Tesis: "Logistic growth"

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Molla, Mohammad Mofigul Islam. "A Stochastic Bayesian Update and Logistic Growth Mapping of Travel-Time Flow Relationship". Diss., North Dakota State University, 2017. http://hdl.handle.net/10365/25911.

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The travel-time flow relationship is not always increasing in nature, it is very difficult to predict precisely. Traditional method fails to replicate this unique conditions. Until millennium, although various researchers and practitioners have given much attention to develop travel-time flow relationships, the advancement to improve travel-time flow relationships was not substantial. The knowledge about the travel-time flow relationship is not commensurate with or parallel to the advancement of new knowledge in other fields. After millennium, most investigators did not devote enough attention to create new knowledge, except for application and performance evaluation of the existing knowledge. Therefore, it is necessary to provide a new theoretical and methodological advancement in travel-time flow relationship. Consequentially, this research proposes a new methodology, which considers stochastic behavior of travel-time flow relationship with probabilistic Bayesian statistics and logistic growth mapping techniques. This research moderately improves the travel-time flow relationship. The unique contribution of this research is that the proposed methods outperforms the existing traditional travel-time flow theory, assumptions, and modeling techniques. The results shows that the proposed model is considerably a good candidate for travel-time predictions. The proposed model performs 36 percent better and accurate travel-time predictions in compared to the existing models. Furthermore, travel-time flow relationship need capacity and free-flow speed estimations. Traditionally, practice of capacity estimation is mostly practical, subjective, and not steady-state capacity. Therefore, a robust and stable capacity-estimation method was developed to eliminate the subjectivity of capacity estimation. The proposed model shows robust and capable of replicating steady-state capacity estimation. The free-flow speed estimation should relate to the traffic-flow speed model while the density is zero. Therefore, this research investigates the existing deterministic speed-density models and recommends a better methodology in free-flow speed estimation. This research presents how the undefined practice of free-flow speed selection can be sensitive. Additionally, finding suitable concurrent travel-time data and traffic volume is crucial and very challenging. To collect concurrent data, this research investigates and develops several technologies such as crowdsource, web app, virtual sensor method, test vehicle, smartphone, global positioning system, and utilized several state and local agencies data collection efforts. Keywords: Travel-Time Flow, Travel-Time Delay, Volume-Delay Function, Travel Time, Origin-Destination Survey, Travel Demand Model, Travel Data Collection, Transportation Survey, Internet Sensor, Crowdsourcing, Virtual Sensor Method, VSM, Transportation Planning, GPS, Smartphone, Loop Detector, Travel -Time Prediction, Travel-Speed Prediction, TDM, Bayesian Inference, Logistic Growth Function.

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Irvine, Paul Michael. "Using a logistic phenology model with improved degree-day accumulators to forecast emergence of pest grasshoppers". Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, 2011, 2011. http://hdl.handle.net/10133/3105.

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Many organisms, especially animals like insects, which depend on the environment for body heat, have growth stages and life cycles that are highly dependent on temperature. To better understand and model how insect life history events progress, for example in the emergence and initial growth of the biogeographical research subjects, we must first understand he relationship between temperature, heat accumulation, and subsequent development. The measure of the integration of heat over time, usually referred to as degree-days, is a widely used science-based method of forecasting, that quantifies heat accumulation based on measured ambient temperature. Some popular methods for calculation of degreedays are the traditional sinusoidal method and the average method. The average method uses only the average of the daily maximum and minimum temperature, and has the advantage that it is very easy to use. However, this simplest method can underestimate the amount of degree-day accumulation that is occurring in the environment of interest, and thus has a greater potential to reduce the accuracy of forecasting insect pest emergence. The sinusoidal method was popularized by Allen (1976, [1]), and gives a better approximation to the actual accumulation of degree-days. Both of these degree-day accumulators are independent of typical heating and cooling patterns during a typical day cycle. To address possible non-symmetrical effect, it was deemed prudent to construct degree-day accumulators to take into account phenomena like sunrise, sunset, and solar noon. Consideration of these temporal factors eliminated the assumption that heating and cooling in a typical day during the growth season is symmetric. In some tested cases, these newer degree-day integrators are more accurate than the traditional sinusoidal method, and in all tested cases, these integrators are more accurate than the average method. After developing the newer degree-day accumulators, we chose to investigate use of a logistic phenology model similar to one used by Onsager and Kemp (1986, [54]) when studying grasshopper development. One reason for studying this model is that it has parameters that are important when considering pest management tactics, such as the required degree-day accumulations needed for insects in immature stages (instars) to be completed, as well as a parameter related to the variability of the grasshopper population. Onsager and Kemp used a nonlinear regression algorithm to find parameters for the model. I constructed a simplex algorithm and studied the effectiveness when searching for parameters for a multi-stage insect population model. While investigating the simplex algorithm, it was found that initial values of parameters for constructing the simplex played a crucial role in obtaining realistic and biologically meaningful parameters from the nonlinear regression. Also, while analyzing this downhill simplex method for finding parameters, it was found there is the potential for the simplex to get trapped in many local minima, and thus produce extraneous or incorrectly fitted parameter estimates, although Onsager and Kemp did not mention this problem. In tests of my methods of fitting, I used an example of daily weather data from Onefour, AB, with a development threshold of 12 ±C and a biofix day of April 1st, as an example. The method could be applied to larger, more extensive datasets that include grasshopper population data on numbers per stage, by date, linked to degree accumulations based on the non-symmetrical method, to determine whether it would offer significant improvement in forecasting accuracy of spring insect pest events, over the long term.
xii, 106 leaves ; 29 cm

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Fay, TH y JC Greeff. "A three species competition model as a decision support tool". Elsevier, 2007. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000167.

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An overcrowding problem of nyala, and lately also of impala in the Ndumo Game Reserve, South Africa, has been detrimental to other species and vegetation structures over a period of two decades. In the present study a deterministic model for three competing species (where two species tend to be overpopulated while the third faces probable localized extinction) is constructed, while future trends coupled with their coexistence are projected. On a mathematical basis, we seek reasons for the failure of the cropping strategies implemented by management over the last two decades, and suggest alternative, scientifical-based approaches to the calculation of cropping quotas to ensure the future coexistence of all three species. A system of three first-order nonlinear differential equations is used, with parameter values based on field data and opinions of specialist ecologists. The effect of various cropping strategies, and the introduction of a fourth species (man as a predator) to the system, is investigated mathematically. This model was implemented as a harvesting strategy in 2002, and is being continuously tested. Final assessment can only be done over a 10–15-year period, but so far indications are promising.

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Fossceco, Stewart Lee. "Logistic growth curve parameter estimates for scrotal circumference and relationships with female reproduction in crossbred sheep". Diss., Virginia Tech, 1991. http://hdl.handle.net/10919/37241.

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Data from two groups of lambs were analyzed. In group one, seasonal patterns of testis growth through 16 mo of age were assessed on 40 spring-born ram lambs (eight Barbados Blackbelly, 10 Suffolk and 22 1/2-Dorset, 1/4-Finnish Landrace, 1/4-Rambouillet). Scrotal circumference (sc) and body weight (wt) were measured at mean ages of 30, 62, 96, 124, 153, 180, 212, 243, 290, 333, 364, 398, 427, 454, 488 and 517 d. A multivariate repeated measures analysis indicated that there were breed differences in ram sc and wt measurements at each age. When logistic growth curves were fit to ram sc data, breed differences were associated with parameters of the logistic curve that defined mature testis size and the period of rapid testis growth. For group two, data were collected on 1,044 lambs from 727 spring lambings over 5 years; 67 sires and 525 dams were represented. Sc and wt were measured in rams at 5 times (mean ages of 44, 63, 97, 129 and 156 d); ewes were weighed at these times and at three additional times (187, 230 and 271 d). All ewe lambs were kept for fall breeding. Fertility, prolificacy and postweaning spring mating behavior of ewes that had lambed were measured. After ewes lambed, they were exposed to vasectomized rams and checked for postweaning spring mating behavior. Restricted maximum likelihood (REML) was used to estimate variance components for additive genetic, ewe, and litter effects in group two Jambs. Heritability estimates for wt at birth to 150 d ranged from .14 to .42. Heritabilities for sc and sc scaled to the 1/3 power of body weight (rsc) ranged from .09 to .57 and from .13 to .55, respectively, and were largest at approximately 90 d. Logistic sc growth curves were fitted to data from individual ram lambs. Heritabilities of the estimated logistic parameters mature sc (A), sc maturing rate (k), age at inflection of the sc growth curve (t₁) and initial 14-d sc (SC14), were estimated at .09±.15, .17±.18, .37±.29 and .40±.14, respectively. Heritability estimates for fertility and spring mating behavior (spbrd) were .04±.13 and .41±.19, respectively. The heritability estimate for prolificacy was zero. Longitudinal additive genetic covariances among wt, sc and rsc at the second, third and fourth measurements were estimated from approximate multivariate REML analysis treating variances as known. Estimated genetic correlations among wts were largest, and ranged from. 77 to .93. Estimated genetic correlations for rsc traits were between .48 and .90. Estimated genetic correlations for sc ranged only from .10 to .67. Pairwise genetic correlations among sc or rsc with fertility or spbrd were estimated to be moderate and positive (.20 and .34, respectively); t₁ had correlations of -.32 and -.48 with fertility and spbrd, respectively.
Ph. D.

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5

Browning, Alexander P. "Stochastic mathematical models of cell proliferation assays". Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/110808/1/Alexander_Browning_Thesis.pdf.

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Cell proliferation assays are routinely used to study collective cell behaviour, and can be interpreted with mathematical models. In this thesis, we apply a computational Bayesian technique to calibrate stochastic discrete mathematical models of cell migration and cell proliferation in the context of a cell proliferation assay. Initially, we use a lattice-based model to explore the optimal duration of a cell proliferation assay. Next, we estimate the parameters in a lattice-free model using three independent experimental data sets. Our model is able to both describe and predict the evolution of the population and spatial structure in a cell proliferation assay.

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6

Johnson, Vicki D. "Growth Mindset as a Predictor of Smoking Cessation". Cleveland State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1246034970.

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7

Wasson, Samantha Rae. "Increasing Introductory Biology Students' Modeling Mastery Through Visualizing Population Growth Models". BYU ScholarsArchive, 2021. https://scholarsarchive.byu.edu/etd/9181.

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In introductory biology, college students are taught to predict how populations will grow and change over time by using population growth models. These models are commonly represented as mathematical equations. However, students consistently struggle when math and biology concepts intersect in the classroom, and these struggles lead to suboptimal understanding of how mathematical population models are designed and used. Education literature suggests that students may struggle with population modeling because of math anxiety, the high cognitive load of the task, and the lack of scaffolding for abstract concepts. In our study, we sought to improve student mastery modeling exponential growth, logistic growth, and Lotka-Volterra predator-prey interactions through using pictorial diagrams in modeling pedagogy. We predicted that these diagrams would reduce the amount of triggered math anxiety, lower the cognitive load of the task through reducing element interactivity, and allow for a more scaffolding for abstract symbols through a pictorial representation bridge. To test the effectiveness of population diagrams, we created two versions of a population modeling lesson plan: one version taught using diagrams then equations, while the other taught using purely equations. We also designed practice and assessment questions that tested calculation and model-building ability. We assessed math anxiety, scientific reasoning ability, and math ability at the beginning of the semester and state anxiety, effort of tasks, and difficulty of tasks during each lesson. Over 200 students from a non-major biology course were randomly assigned to each group, and all were given a pre-assessment, four lessons, a practice test, and a unit test on population modeling. Our findings show that while the addition of pictorial models to the traditional pedagogy did not have a significant effect on exponential and logistic growth model mastery, students that were exposed to predator-prey diagrams were more able to create a new model for a three-level predator-prey interaction than students that were only given traditional pedagogy. In addition, students who were exposed to predator-prey interaction diagrams before they derived equations reported a lower cognitive load than students who were only exposed to equations. Although diagrams were not a more helpful calculation tool for students than traditional equations, using population diagrams before to equation derivation may help improve student mastery of growth model creation.

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Murphy, Stephen J. "Vegetation Dynamics of an Old-growth Mixed Mesophytic Forest in Southeastern Ohio, USA". Ohio University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1350941088.

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Bara, Carlos Roberto Francisco. "Variáveis relevantes para as empresas de alto crescimento no Brasil". Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/12/12139/tde-11062018-114840/.

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Empreendedorismo tem sido objeto de incentivo no mundo e no Brasil, dada a sua significante contribuição para o desenvolvimento econômico e social de uma nação. Observa-se que a maioria das empresas, existentes ou novas, evolui de forma lenta e gradual; no entanto, reduzida parcela apresenta um padrão diferente, com crescimento elevado em faturamento ou número de colaboradores: são as empresas de alto crescimento (EACs). Tais empresas são as responsáveis por grande parte da geração de empregos (Birch, 1981; Coad, Daunfeldt, Holzl, Johansson, & Nightingale, 2014; Henrekson & Johansson, 2010; OECD, 2010). A presente tese procurou identificar as variáveis que ajudam a explicar o desempenho das EACs no Brasil, classificadas conforme critério da OECD (2007). Foi conduzida uma pesquisa com 470 empresas brasileiras, que coletou mais de 30 variáveis preditoras categóricas ou métricas, utilizadas no modelo Regressão Logística. Foram identificadas algumas variáveis alinhadas com a literatura e outras menos intuitivas e documentadas. Comprovou-se o aumento da probabilidade de EACs quando se relacionavam com aceleradoras, recebiam premiações ou eram spin-offs de outras empresas. Em função das altas taxas de juros bancários e da cultura empreendedora no Brasil, surpreendeu o impacto positivo de empréstimos bancários e a percepção dos empreendedores sobre registrar marcas comerciais, bem como o impacto negativo da percepção sobre propaganda em mídia digital e doações de instituições de fomento, relacionadas às EACs. Análises adicionais com o subgrupo de EACs caracterizadas como gazelas foram feitas. Embora apresente limitações de surveys e outras, a tese confirmou parte dos resultados da literatura sobre empreendedorismo e identificou avenidas para futuras pesquisas.
Entrepreneurship has been object of encouragement in the world and in Brazil, given its significant contribution to the economic and social development of a nation. It is observed that the majority of companies, existing or new, are developing slowly and gradually; however, small share presents a different pattern, with high growth in sales or number of employees: they are the high growth firms (HGFs). These firms are responsible for a large part of job creation (Birch, 1981; Coad, Daunfeldt, Holzl, Johansson, & Nightingale, 2014, Henrekson & Johansson, 2010, OECD, 2010). This thesis aimed to identify the variables that help to explain the performance of HGFs in Brazil, according to OECD (2007) criterion. A survey with 470 Brazilian companies was conducted, collecting more than 30 categorical or metric predictor variables, used in the Logistic Regression model. Some identified variables were aligned to literature, but others less intuitive or documented. It was confirmed the increase in the probability of HGFs when they related to accelerators, received awards, or were spin-offs of other companies. As a consequence of the high banking interest rates and the entrepreneurship culture in Brazil, surprised the positive impact of bank loans and the entrepreneurs\' perception of trademark registration, as well as the negative impact of perception on advertising in digital media and donations from development institutions, related to HGFs. Additional analyzes with the subgroup of HGFs characterized as gazelles were made. Although it presents limitations of surveys and others, the thesis confirmed part of the results of the literature on entrepreneurship and identified avenues for future researches.

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Atems, Bebonchu. "Essays in nonlinear macroeconomic modeling and econometrics". Diss., Kansas State University, 2011. http://hdl.handle.net/2097/11985.

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Doctor of Philosophy
Department of Economics
Lance J. Bachmeier
This dissertation consists of three essays in nonlinear macroeconomic modeling and econometrics. In the first essay, we decompose oil price movements into oil demand (stock market) shocks and oil supply (oil-market) shocks, and examine the response of the stock market to these shocks. We find that when oil prices are “net-increasing”, a stock market shock that causes the S&P 500 to rise by one percentage point will cause the price of oil to rise approximately 0.2 percentage points, with a statistically significant positive effect one day after the stock market shock. On the other hand, the response of the stock market to an oil market shock is a decline of 6.8 percent when the price of oil doubles. For other days, the initial response of the oil market to a stock market shock is the same as in the net oil price increase case (by construction). We then analyze the response of monetary policy to the identified stock market and oil market shocks and find that short-term interest rates respond to the stock market shocks but not the oil market shocks. Finally, we evaluate the predictive power of the decomposed stock market and oil shocks relative to the change in the price of oil. We find statistically significant gains in both the in-sample fit and out-of-sample forecast accuracy when using the identified stock market and oil market shocks rather than the change in the price of oil. The second essay revisits the statistical specification of near-multicollinearity in the logistic regression model using the Probabilistic Reduction approach. We argue that the ceteris paribus clause invoked with near-multicollinearity is rather misleading. This assumption states that one can assess the impact of near-multicollinearity by holding the parameters of the logistic regression model constant, while examining the impact on their standard errors and t-ratios as the correlation (\rho) between the regressors increases. Using the Probabilistic Reduction approach, we derive the parameters (and related statisitics) of the logistic regression model and show that they are functions of \rho , indicating the ceteris paribus clause in the traditional account of near multicollinearity is unattainable. Monte carlo simulations in the paper confirm these findings. We also show that traditional near-multicollinearity diagnostics, such as the variance inflation factor and condition number can fail to detect near-multicollinearity. Overall, the paper finds that near-multicollinearity in the logistic model is highly variable and may not lead to the problems indicated by the traditional account. Therefore, unexpected, unreliable or unstable estimates and inferences should not be blamed on near-multicollinearity. Rather the modeler should return to economic theory or statistical respecification of their model to address these problems. The third essay examines the correlations between income inequality and economic growth using a panel of income distribution data for 3,109 counties of the U.S. We examine the non-spatial dynamic correlations between county inequality and growth using a System GMM approach, and find significant negative relationships between changes in inequality in one period and growth in the subsequent period. We show that this finding is robust across different sample sizes. We further argue that because the space-specific time-invariant variables that affect economic growth and inequality can differ significantly across counties, failure to incorporate spatial effects into a model of growth and inequality may lead to biased results.We assume that dependence among counties only arises from the disturbance process, hence the estimation of a spatial error model. Our results indicate that the bias in the parameter for inequality amounts to about 2.66 percent, while that for initial income amounts to about 21.51 percent.

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Silva, Carlos Patricio Montenegro. "Inferência bayesiana em modelos de dinâmica de populações biológicas com termo de perturbação assimétrico". Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/45/45133/tde-15052016-104959/.

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Neste trabalho de tese, estudamos o modelo de crescimento logístico de populações biológicas utilizando a abordagem de espaço de estados. Os estados não observados são as biomassas anuais, a equação de observação é linear e a equação de estado é não linear. As distribuições de probabilidade utilizadas para os termos de erro de observação aditivos são: Normal, t-student, Skew-normal e Skew-t. As distribuições Log-normal, Log-t, Log-skew-normal e Log-skew-t são consideradas para os erros de observação multiplicativos. A inferência nos modelos é realizada considerando-se métodos Bayesianos e as distribuições a posterior de interesse são aproximadas utilizando-se algoritmos MCMC e a aproximação de Laplace. Apresentamos duas aplicações, a primeira referente a pesca de camarão marinho na costa do Chile, na qual a variável observável é o rendimento médio anual de pesca (captura por unidade de esforço média). Na segunda é considerada a pesca de lagostim vermelho na costa de Chile, na qual além do rendimento médio anual da pesca, observa-se as estimativas anuais de biomassa vulnerável, obtidas através de estudos de área varrida. Para o primeiro conjunto de dados, os modelos com erros de observação multiplicativos têm melhor performance, particularmente os modelos Log-skew-normal e Log-skew-t. Considerando estes resultados, no segundo caso utilizamos somente erros multiplicativos e a distribuição a posteriori preditiva mostra que cada variável observável parece ter sua própria família de distribuição de probabilidades. Além disso, os resultados também revelam uma crescente complexidade do modelo ao incorporar a classe mais geral de distribuições assimétricas.
We study the logistic population growth model using a state-space approach. The non observable states are the annual biomass of the population with a linear observation equation and a non-linear state equation. The probability distribution used for the additives observation error terms are Normal, Student-t, Skew-normal and Skew-t, and Log-normal, Log-t, Log-skew-normal and Log-skew-t for multiplicative observation errors terms. The inference about the parameters of the models is performed using Bayesian methods, with MCMC algorithms and Laplace approximations. We present two applications to real data sets. The first in marine shrimp population off the coast of Chile, where observable variable is the average annual fishing yield. The second application is for the population of the red squat lobster off Chile, where in addition to the average annual fishing yield, a second observable variable was included. In the first case, the multiplicative observational errors models presented the best results. Particularly the Log-skew-normal and Log-skew-t models has the better performances. Considering these results, in the second application we use only multiplicative observation errors models.

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Gebhardt, Albertus Johannes. "Ensuring sufficient capacity of logistical infrastructure for future growth". Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86539.

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Thesis (MComm)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: This study explore how forecasting techniques can be combined in linear programming (LP) as a tool to optimise the parameters of forecasting methods in order to ensure sufficient capacity of logistic infrastructure exist for future growth. This study will use greenfield and brownfield projects from Sasol, a petrochemical company from South Africa, to test the methodology on. The methodology followed in the study was to firstly look at previous literature studies on logistical infrastructure and how to create sufficient capacity. Secondly, understandings of supply chain planning principles in general as well as supply chain planning in context of Sasol were investigated. Thirdly, different forecasting methods like; qualitative include judgemental, life cycle, Delphi method, market research etc. and quantitative methods including time series and causal methodologies had been investigated. Fourthly, decision making tools to incorporate multiple forecasts were investigated to understand why Sasol decided to use i2. Fifthly, the current capital project approach in Sasol had been investigated to fully understand where room for improvements would be possible. Finally the theory from the study was applied on two different projects in Sasol, one greenfield and one brownfield project. The results found that by using sound supply chain planning methodologies, sound supply chain design principles and multiple forecasts being combined by using LP decision making tools a better decision can be made with regards to logistical infrastructure investment as well as ensuring sufficient logistical infrastructure capacity. The two case studies have shown that this approach is flexible enough, apart from a few minor changes and can be adopted for both scenarios and that great results can be achieved. Logistical infrastructure could be optimised due to collaboration and the overall costs and performance of a supply chain improved.
AFRIKAANSE OPSOMMING: Hierdie studie ondersoek hoe lineêre programmering ( LP ), as n hulpmiddel, gebruik kan word om vooruitskattingstegnieke te kombineer om sodoende die vooruitskattingsmetodes te optimaliseer en te verseker dat voldoende kapasiteit van logistieke infrastruktuur bestaan vir toekomstige groei. Hierdie studie se metodes sal getoets word op groenveld- en bruinveldprojekte van Sasol , 'n petrochemiese maatskappy van Suid –Afrika. Die metode gevolg tydens die studie, was eerstens om te kyk na vorige literatuurstudies oor logistieke infrastruktuur en hoe om voldoende kapasiteit te skep. Tweedens, om ‘n breë oorsig van die beginsels van voorsieningsketting-beplanning te bekom sowel as voorsieningsketting-beplanning in die konteks van Sasol te ondersoek. Derdens, verskillende vootuitskattingsmetodes soos kwalitatiewe metodes (insluitend veroordelende-, lewensiklus- en Delphi-metode en marknavorsing) en kwantitatiewe metodes (insluitend die tydreeks- en oorsaaklike metodes) is geondersoek. In die vierde plek is besluitnemingshulpmiddels, wat verskeie vooruitskattings kombineer, geondersoek om te verstaan waarom Sasol besluit het om i2 aan te koop. In die vyfde plek is die metode van Sasol se kapitaalprojekte geondersoek om te verstaan of daar nie moontlik ruimte vir verbeterings sou wees nie. Laastens is die studie se metode op twee projekte van Sasol toegepas, een groenveld- en een bruinveldprojek. In die studie is gevind dat beter besluite geneem kan word aangaande beleggings in logistieke infrastruktuur en om te verskere daar is voldoende logistieke infrastruktuur kapasiteit - deur gebruik te maak van optimale metodes in voorsieningsketting-beplanning en voorsieningskettingontwerp. Die twee gevallestudies het getoon dat hierdie benadering buigsaam genoeg is, afgesien van 'n paar klein veranderinge, om vir beide moontlikhede gebruik te kan word en goeie resultate te behaal. Deur die samewerking van verskeie besigheidseenhede kon logistieke infrastruktuur geoptimaliseer word terwyl die kostes en algehele prestasie van voorsieningsketting verbeter kon word.

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Mytilinaios, Ioannis. "Modelling the impact of mild food processing conditions on the microbiological safety of food". Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/7914.

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There is significant interest by the food industry in applying milder processing conditions. A major area of research within predictive modelling has been the search for models which accurately predict the effect of combining multiple processes or hurdles. For a mild process, which has temperature as the major microbial injury step, the effect of the other combined hurdles in inhibiting growth of the injured organisms must be understood. The latter means that the inoculum size dependency of the time to growth must also be fully understood. This essentially links injury steps with the potential for growth. Herein, we have been developing the use of optical density (O.D) for obtaining growth rates and lag times using multiple inocula rather than using the traditional methods which use one single inoculum. All analyses were performed in the Bioscreen analyser which measures O.D. The time to detection (TTD) was defined as the time needed for each inoculum to reach an O.D=0.2 and O.D was related to microbial numbers with simple calibration curves. Several primary models were used to predict growth curves from O.D data and it was shown that the classic logistic, the Baranyi and the 3-phase linear model (3-PLM) were the most capable primary models of those examined while the modified Gompertz and modified logistic could not reproduce TTD data. Using the Malthusian approximation of the logistic model the effect of mild temperature shifts was studied. The data obtained showed that for mild temperature shifts, growth rates quickly changed to the new environment without the induction of lags. The growth of Listeria monocytogenes, Salmonella Typhimurium and Escherichia coli was studied at 30⁰C and/or 37⁰C, in different NaCl concentrations, pH and their combinations. The classical 3-parameter logistic with lag model was rearranged to provide the theoretical foundation for the observed TTD and accurate growth rates and lag times could be estimated. As the conditions became more unfavourable, the lag time increased while the growth rate decreased. Also, the growth rate was found to be independent from the inoculum size; the inoculum size affected only the TTD. The Minimum Inhibitory Concentration (MICNaCl and MICpH) was calculated using the Lambert and Pearson model (LPM) and also the Growth/No Growth (G/NG) interface was determined using combinations of NaCl and pH. These data were transformed in rate to detection (RTD) and fitted with a response surface model (RSM) which was subsequently compared with the Extended LPM (ELPM). The LPM and the ELPM could analyse results from individual and combined inhibitors, respectively. Following a mild thermal process a lag due to thermal injury was also induced, the magnitude of which was dependent on the organism and environmental conditions; the observed distribution of the lags appeared, in general, to follow the Log-normal distribution. After the lag period due to injury, growth recommenced at the rate dictated by the growth environment present. Traditional growth curves were constructed and compared with the data obtained from the Bioscreen under the same conditions. From the results obtained, it can be suggested that the increased lag times and growth rates obtained from the traditional plate counts compared with the values obtained from the Bioscreen microbiological analyser, might be an artifact of the plating method or may be due to the use of the modified Gompertz to study the growth. In conclusion, O.D can be used to accurately determine growth parameters, to give a better understanding and quantify the G/NG interface and to examine a wealth of phenomena such as fluctuating temperatures and mild thermal treatments. The comparison between the traditional growth curves against the data obtained from the Bioscreen showed that the TTD method is a rapid, more accurate and cheaper method than the traditional plate count method which in combination with the models developed herein can offer new possibilities both to the research and the food industry.

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14

Conradie, Jessica Kate. "Modelling population dynamics of Leysera gnaphalodes in Namaqualand, South Africa". Diss., Connect to this title online, 2003. http://upetd.up.ac.za/thesis/available/etd-02182004-083915.

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15

Stull, Kyra Elizabeth. "An osteometric evaluation of age and sex differences in the long bones of South African children from the Western Cape". Thesis, University of Pretoria, 2013. http://hdl.handle.net/2263/40263.

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The main goal of a forensic anthropological analysis of unidentified human remains is to establish an accurate biological profile. The largest obstacle in the creation or validation of techniques specific for subadults is the lack of large, modern samples. Techniques created for subadults were mainly derived from antiquated North American or European samples and thus inapplicable to a modern South African population as the techniques lack diversity and ignore the secular trends in modern children. This research provides accurate and reliable methods to estimate age and sex of South African subadults aged birth to 12 years from long bone lengths and breadths, as no appropriate techniques exist. Standard postcraniometric variables (n = 18) were collected from six long bones on 1380 (males = 804, females = 506) Lodox Statscan-generated radiographic images housed at the Forensic Pathology Service, Salt River and the Red Cross War Memorial Children’s Hospital in Cape Town, South Africa. Measurement definitions were derived from and/or follow studies in fetal and subadult osteology and longitudinal growth studies. Radiographic images were generated between 2007 and 2012, thus the majority of children (70%) were born after 2000 and thus reflect the modern population. Because basis splines and multivariate adaptive regression splines (MARS) are nonparametric the 95% prediction intervals associated with each age at death model were calculated with cross-validation. Numerous classification methods were employed namely linear, quadratic, and flexible discriminant analysis, logistic regression, naïve Bayes, and random forests to identify the method that consistently yielded the lowest error rates. Because some of the multivariate subsets demonstrated small sample sizes, the classification accuracies were bootstrapped to validate results. Both univariate and multivariate models were employed in the age and sex estimation analyses. Standard errors for the age estimation models were smaller in most of the multivariate models with the exception of the univariate humerus, femur, and tibia diaphyseal lengths. Univariate models provide narrower age estimates at the younger ages but the multivariate models provide narrower age estimates at the older ages. Diaphyseal lengths did not demonstrate any significant sex differences at any age, but diaphyseal breadths demonstrated significant sex differences throughout the majority of the ages. Classification methods utilizing multivariate subsets achieved the highest accuracies, which offer practical applicability in forensic anthropology (81% to 90%). Whereas logistic regression yielded the highest classification accuracies for univariate models, FDA yielded the highest classification accuracies for multivariate models. This study is the first to successfully estimate subadult age and sex using an extensive number of measurements, univariate and multivariate models, and robust statistical analyses. The success of the current study is directly related to the large, modern sample size, which ultimately captured a wider range of human variation than previously collected for subadult diaphyseal dimensions.
Thesis (PhD)--University of Pretoria, 2013.
gm2014
Anatomy
unrestricted

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16

Jönsson, Ingela y Mattias Nilsson. "Klassiska populationsmodeller kontra stokastiska : En simuleringsstudie ur matematiskt och datalogiskt perspektiv". Thesis, Växjö University, School of Mathematics and Systems Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-2262.

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I detta tvärvetenskapliga arbete studeras från den matematiska sidan tre klassiska populationsmodeller: Malthus tillväxtmodell, Verhulsts logistiska modell och Lotka-Volterras jägarebytesmodell. De klassiska modellerna jämförs med stokastiska. De stokastiska modeller som studeras är födelsedödsprocesser och deras diffusionsapproximation. Jämförelse görs med medelvärdesbildade simuleringar.

Det krävs många simuleringar för att kunna genomföra jämförelserna. Dessa simuleringar måste utföras i datormiljö och det är här den datalogiska aspekten av arbetet kommer in. Modellerna och deras resultathantering har implementerats i både MatLab och i C, för att kunna möjliggöra en undersökning om skillnaderna i tidsåtgången mellan de båda språken, under genomförandet av ovan nämnda jämförelser. Försök till tidsoptimering utförs och även användarvänligheten under implementeringen av de matematiska problemen i de båda språken behandlas.

Följande matematiska slutsatser har dragits, att de medelvärdesbildade lösningarna inte alltid sammanfaller med de klassiska modellerna när de simuleras på stora tidsintervall. I den logistiska modellen samt i Lotka-Volterras modell dör förr eller senare de stokastiska simuleringarna ut när tiden går mot oändligheten, medan deras deterministiska representation lever vidare. I den exponentiella modellen sammanfaller medelvärdet av de stokastiska simuleringarna med den deterministiska lösningen, dock blir spridningen stor för de stokastiska simuleringarna när de utförs på stora tidsintervall.

Datalogiska slutsatser som har dragits är att när det kommer till att implementera få modeller, samt resultatbearbetning av dessa, som ska användas upprepade gånger, är C det bäst lämpade språket då det visat sig vara betydligt snabbare under exekvering än vad MatLab är. Dock måste hänsyn tas till alla de svårigheter som implementeringen i C drar med sig. Dessa svårigheter kan till stor del undvikas om implementeringen istället sker i MatLab, då det därmed finns tillgång till en uppsjö av väl lämpade funktioner och färdiga matematiska lösningar.

In this interdisciplinary study, three classic population models will be studied from a mathematical view: Malthus’ growth, Verhulst’s logistic model and Lotka-Volterra’s model for hunter and prey. The classic models are being compared to the stochastic ones. The stochastic models studied are the birthdeath processes and their diffusion approximation. Comparisons are made by averaging simulations.

It requires numerous simulations to carry out the comparisons. The simulations must be carried out on a computer and this is where the computer science emerges to the project. The models, along with the handling of the results, have been implemented in both Mat- Lab and in C in order to allow a comparison between the two languages whilst executing the above mentioned study. Attempts to time optimization and an evaluation concerning the user-friendliness regarding the implementation of mathematical problems will be performed.

Mathematic conclusions, which have been drawn, are that the averaging solutions do not always coincide with the traditional models when they are being simulated over large time. In the logistic model and in Lotka-Volterra’s model the stochastic simulations will sooner or later die when the time is moving towards infinity, whilst their deterministic representation keeps on living. In the exponential model, the mean values of the stochastic simulations and of the deterministic solution coincide. There is, however, a large spread for the stochastic simulations when they are carried out over a large time.

Computer scientific conclusions drawn from the study includes that when it comes to implementing a few models, along with the handling of the results, to be used repeatedly, C is the most appropriate language as it proved to be significantly faster during execution. However, all of the difficulties during the implementation of mathematical problems in C must be kept in mind. These difficulties can be avoided if the implementation instead takes place in MatLab, where a numerous of mathematical functions and solutions will be available.

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17

Maraschin, Clarice. "Localização comercial intra-urbana : análise de crescimento através do modelo logístico". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/18680.

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Este trabalho investiga os processos de crescimento e evolução das localizações comerciais no espaço urbano. A formação e o desenvolvimento de múltiplos núcleos comerciais é parte do cenário urbano contemporâneo, criando padrões espaciais e temporais heterogêneos, que desafiam a compreensão de teóricos e planejadores. O estudo desses processos requer abordagens dinâmicas, compatíveis com a escala e a velocidade das mudanças. Nesse contexto, recorta-se como problema de pesquisa a modelagem do crescimento das localizações comerciais em setores urbanos, ao longo do tempo. O trabalho propõe a representação da dinâmica de crescimento quantitativo do comércio no espaço urbano através da distribuição logística, um modelo dinâmico e não-linear, capaz de descrever tipos de crescimento com capacidade limitada. O modelo adotado pressupõe um processo descentralizado de tomada de decisões individuais de localização por parte dos agentes - os lojistas - condicionados pelas decisões dos demais. Tais decisões dependem da interação com um ambiente que está em transformação, portanto as respostas também variam. Nesta concepção, forças de aceleração e desaceleração do crescimento das localizações comerciais, que emanam do processo de estruturação espacial urbana, são filtradas através de um processo de leitura e percepção por parte dos agentes. O modelo proposto é validado em quatro setores na cidade de Porto Alegre: Centro, Azenha, Menino Deus e Iguatemi, considerando dados de número de estabelecimentos varejistas ao longo de uma série temporal de 23 anos, de 1983 a 2006. Nesta pesquisa, o modelo logístico também foi explorado como instrumento de descrição e análise de dois problemas relacionados ao crescimento das localizações comerciais em setores urbanos. O primeiro diz respeito aos fatores envolvidos em tal crescimento. A hipótese adotada é que diferenças no processo de estruturação espacial urbana teriam capacidade de produzir uma especificidade no processo de crescimento do comércio em cada área considerada. Diferentes indicadores da estrutura espacial urbana são relacionados à dinâmica de crescimento em cada área, visando identificar os fatores mais relevantes a atuar nesse processo. O segundo problema envolve a aplicação do modelo logístico para o caso da implantação de um grande equipamento comercial, do tipo shopping center, avaliando como este afeta o crescimento do comércio no seu entorno. A investigação demonstra que o modelo proposto descreve o crescimento das localizações comerciais com alto grau de correlação com os dados empíricos em todas as áreas estudadas. O trabalho evidencia também que o modelo possibilita associar os fatores da estrutura espacial urbana ao crescimento do comércio. O modelo também se mostrou um instrumento válido para a análise do impacto da implantação de grandes equipamentos comerciais sobre o processo de crescimento do comércio no seu entorno.
This thesis investigates growth and evolution in retail location. The presence of multiple retail centers is an essential part of the contemporary urban scene, leading to heterogeneous spatial and temporal patterns, whose comprehension defies scholars and planners. Dynamic approaches are required for studying those processes of urban change, considering the scale and speed of change. In this context, this study focuses on modeling the growth of retail location in urban areas through time. To represent quantitative growth of retail location, the work proposes the use of logistic model, a non-linear model designed to describe a specific capacitated growing dynamics. The model assumes a decentralized process of individual location decisions taken by agents – the retailers – constrained by others decisions. Such decisions interact on a changing environment, thus, the answers also change. In this sense, accelerating and deterring forces for retail location growing, emanating from urban spatial structure, pass through a sort of filtering process: the way agents perceive and interpret the environment. Proposed model is validated in four areas in the city of Porto Alegre, Brazil: Centro, Azenha, Menino Deus and Iguatemi, considering data on number of retail establishment through a temporal data set of 23 years, from 1983 to 2006. In this study, logistic model has also been applied to describe and analyze two problems regarding retail location growth. The first problem refers to the causal factors involved in such growth process. The hypothesis adopted is that differences in spatial structuration process are able to produce a specific pattern of temporal growth. Different urban spatial structure indicators are then related to dynamics of growth in each area, trying to identify the most relevant aspects affecting this process. The second problem involves the use of logistic model referring to the case of large retail formats – such as regional shopping centers - aiming to understand the impact of such planned centers on quantitative retail growth. The investigation demonstrates that proposed model describes the growing of retail location with high levels of correlation to empirical data in all studied areas. It also shows that is possible to relate urban spatial structure factors to retail location growth. The model also performs as a valid instrument of impact analysis of large retail formats on the retail growth process at its neighborhood.

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18

Nilsson, Mattias y Ingela Jönsson. "Klassiska populationsmodeller kontra stokastiska : En simuleringsstudie ur matematiskt och datalogiskt perspektiv". Thesis, Växjö University, School of Mathematics and Systems Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-2263.

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I detta tvärvetenskapliga arbete studeras från den matematiska sidan tre klassiska populationsmodeller: Malthus tillväxtmodell, Verhulsts logistiska modell och Lotka-Volterras jägarebytesmodell. De klassiska modellerna jämförs med stokastiska. De stokastiska modeller som studeras är födelsedödsprocesser och deras diffusionsapproximation. Jämförelse görs med medelvärdesbildade simuleringar.

Det krävs många simuleringar för att kunna genomföra jämförelserna. Dessa simuleringar måste utföras i datormiljö och det är här den datalogiska aspekten av arbetet kommer in. Modellerna och deras resultathantering har implementerats i både MatLab och i C, för att kunna möjliggöra en undersökning om skillnaderna i tidsåtgången mellan de båda språken, under genomförandet av ovan nämnda jämförelser. Försök till tidsoptimering utförs och även användarvänligheten under implementeringen av de matematiska problemen i de båda språken behandlas.

Följande matematiska slutsatser har dragits, att de medelvärdesbildade lösningarna inte alltid sammanfaller med de klassiska modellerna när de simuleras på stora tidsintervall. I den logistiska modellen samt i Lotka-Volterras modell dör förr eller senare de stokastiska simuleringarna ut när tiden går mot oändligheten, medan deras deterministiska representation lever vidare. I den exponentiella modellen sammanfaller medelvärdet av de stokastiska simuleringarna med den deterministiska lösningen, dock blir spridningen stor för de stokastiska simuleringarna när de utförs på stora tidsintervall.

Datalogiska slutsatser som har dragits är att när det kommer till att implementera få modeller, samt resultatbearbetning av dessa, som ska användas upprepade gånger, är C det bäst lämpade språket då det visat sig vara betydligt snabbare under exekvering än vad MatLab är. Dock måste hänsyn tas till alla de svårigheter som implementeringen i C drar med sig. Dessa svårigheter kan till stor del undvikas om implementeringen istället sker i MatLab, då det därmed finns tillgång till en uppsjö av väl lämpade funktioner och färdiga matematiska lösningar.

In this interdisciplinary study, three classic population models will be studied from a mathematical view: Malthus’ growth, Verhulst’s logistic model and Lotka-Volterra’s model for hunter and prey. The classic models are being compared to the stochastic ones. The stochastic models studied are the birthdeath processes and their diffusion approximation. Comparisons are made by averaging simulations.

It requires numerous simulations to carry out the comparisons. The simulations must be carried out on a computer and this is where the computer science emerges to the project. The models, along with the handling of the results, have been implemented in both MatLab and in C in order to allow a comparison between the two languages whilst executing the above mentioned study. Attempts to time optimization and an evaluation concerning the user-friendliness regarding the implementation of mathematical problems will be performed.

Mathematic conclusions, which have been drawn, are that the averaging solutions do not always coincide with the traditional models when they are being simulated over large time. In the logistic model and in Lotka-Volterra’s model the stochastic simulations will sooner or later die when the time is moving towards infinity, whilst their deterministic representation keeps on living. In the exponential model, the mean values of the stochastic simulations and of the deterministic solution coincide. There is, however, a large spread for the stochastic simulations when they are carried out over a large time.

Computer scientific conclusions drawn from the study includes that when it comes to implementing a few models, along with the handling of the results, to be used repeatedly, C is the most appropriate language as it proved to be significantly faster during execution. However, all of the difficulties during the implementation of mathematical problems in C must be kept in mind. These difficulties can be avoided if the implementation instead takes place in MatLab, where a numerous of mathematical functions and solutions will be available.

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19

Florby, Henrik y Marcus Justad. "International Logistics : Realizing the coherence between efficient logistics strategy and international growth". Thesis, University of Kalmar, Baltic Business School, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hik:diva-1295.

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The world economy is in a transition period never experienced before, One of the main realising factors, boosting economy growth, is the catch up of many emerging countries. The emerging countries impose new competitive dimensions to the global economy, forcing well established multinational corporations into new competitive situations, brining both opportunities and threats.

The construction equipment industry has entered a condition of unprecedented growth. The total market demand has increased significantly and the demand development is prospected to continue for many more years. To keep up with the market demand and the sales opportunities, it is important to have machines available in the market. This impose that the logistic strategy is getting more important for companies in order to keep up with the prospected sales opportunities.

This Masters thesis is initiated by our case company, Volvo Construction Equipment International, currently suffering from an inefficient logistics strategy constraining international growth.

Based on our analysis and conclusion, Volvo Construction Equipment is recommended to move from transaction selling, spot market like international logistics strategy towards a relationship marketing based logistics strategy establishing in-depth collaborations with key account shipping suppliers. Furthermore, we recommend that Volvo CE should consider a logistics management function in order to facilitate the inter-organizational flow of logistics information.

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20

Santos, Alessandro Souza. "Modelagem do escoamento de granéis agrícolas aplicada à estratégia operacional nos terminais portuários da região sudeste do Brasil". Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/3/3135/tde-06052015-102551/.

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O processo de crescimento da produção da soja e a necessidade de eficiência em seu escoamento, atrelado a um menor custo logístico total, demanda a elaboração de um planejamento operacional que delimite as áreas de influências dos portos, as hinterlands; e mantenha a estabilidade do mercado. Entretanto, o menor custo logístico total para escoamento da produção não é respeitado em alguns fluxos por conta de restrições de transporte multimodal. Em consonância a isso, os projetos futuros de implantação de novas rotas para o escoamento da produção, delimitadas por investimentos em transporte multimodal, instalação de novos portos e terminais de transbordo de carga, vem interferindo nessas áreas de influência aumentando a dinâmica do negócio. Este estudo possui como objetivo caracterizar a dinâmica das rotas de escoamento da produção, listar as suas interferências, mapear a discussão a respeito do conceito de hinterlands e apresentar metodologias para sua delimitação. O modelo proposto será aplicado a todos os portos que participaram do comércio exterior da soja em 2011, com destaque para o Píer 3, da Vale S/A. Como resultados esperados, deverão ser respondidos dois questionamentos fundamentais: 1) qual a importância do Píer 3, da Vale S/A, no que tange ao escoamento da safra agrícola brasileira, e na sua competitividade de custo logístico total? 2) O terminal será necessário no futuro?
The growth process of soybean production and the need for efficiency in its flow, coupled to a lower total logistics costs, demand the development of an operational plan that demarcates the areas of influence of the ports, the Hinterlands, and maintain market stability. However, the lowest total logistics costs for production flow are not respected in some scenarios due to restrictions of the multimodal transportation. Correspondingly, future projects to implement new routes for the production flow, bounded by investments in multimodal transport, installation of new ports and terminals cargo transshipment, are interfering in these areas of influence increasing business dynamics. This study aims to characterize the dynamics of the flow of production routes, list their interference, map the discussion about the concept of hinterlands and present methodologies for its delimitation. The proposed model will be applied to all ports participating in the foreign trade of soybeans in 2011, with emphasis on the VALE S/A Pier 3. The expected results should answer two fundamental questions: 1) what is the importance of VALE S/A Pier 3 regarding the distribution of the Brazilian harvest, and the competitiveness of total logistics costs? 2) The terminal will be needed in the future?

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Martins, Maria Cristina. "Análise de resíduos projetados em modelos não-lineares de regressão: uma aplicação em crescimento de frutos". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/11/11134/tde-19022013-171004/.

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Alguns aspectos devem ser considerados nos trabalhos com frutíferas como o ponto adequado de colheita e estratégias de conservação, sendo fundamental a análise do crescimento e desenvolvimento dos frutos. Vários tipos de modelos estatísticos podem descrever os processos de crescimento envolvidos no sistema de produção vegetal, sendo os modelos não lineares considerados mais adequados para esse tipo de estudo. Para que os resultados obtidos no ajuste do modelo sejam válidos é necessário verificar a qualidade de ajuste por meio de uma análise dos resíduos. A distribuição dos resíduos ordinários para os modelos de regressão não linear, é matematicamente trabalhosa e os critérios de diagnóstico são falhos, principalmente em pequenas amostras. Diante de tal fato, Cook e Tsai (1985) definiram o resíduo projetado. O comportamento dos resíduos projetados é melhor do que o dos resíduos ordinários, pois suas propriedades são mais próximas das correspondentes ao resíduo ordinário da regressão normal linear. O ganho é substancial se o teste para a medida de não linearidade for significativo. Por meio dos ajustes dos modelos logístico e de Gompertz aos dados de comprimento de peras foi realizada a análise dos resíduos ordinários e dos resíduos projetados, a fim de evidenciar suas vantagens. Os resíduos projetados se mostraram viáveis para diagnóstico dos modelos e descartaram possíveis tendências apresentadas pelos resíduos normalizados.
Some aspects must be considered in the works with fruit tree such as the appropriate point of harvest and conservation strategies, being fundamental the analysis of growth and fruit developments. Several types of statistical models can describe the growth processes involved in plant production system and the non-linear models are considered more suitable for this type of study. For the results obtained from the model fit to be valid is necessary to check the quality of fit through a residual analysis. The distribution of the ordinary residuals in the non-linear regression models is mathematically complicated and the diagnostic criteria are not precise, mainly in small samples. To overcome this fact, Cook and Tsai (1985) defined the projected residual. The behaviour of the projected residuals is better than the ordinary residuals since their properties are closer to those corresponding to the ordinary residuals for the normal linear regression. The gain is substantial if the test for non-linearity is significant. Through the fit of the logistic and Gompertz models to the pears length data, it was performed an analysis of the ordinary and projected residuals in order to demonstrate their advantages. The projected residuals showed more feasible for the diagnostic of the models and ruled out possible trends presented by normalized residuals.

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22

Jin, Wang. "Investigating the reproducibility of in vitro cell biology assays using mathematical models". Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/109790/1/Wang_Jin_Thesis.pdf.

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In vitro cell biology assays are routinely used to study cancer spreading, drug design and tissue repair. However, issues associated with reproducibility are reported in literature. In this thesis we investigate the overlooked source of variability that affects the reproducibility of cell biology assays, using a combined mathematical and experimental approach. By calibrating mathematical models to experimental data, we find that the initial degree of confluence significantly affects cell motility. Following the similar approach, we identify the two-phase growth in scratch assays. We then propose a proliferation mechanism for lattice-based, random walk models, which accounts for biologically more realistic crowding effects. At last, we use a lattice-based, random walk model to mimic the passaging process and find that the passage number could significantly affect the wound closure in scratch assays.

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23

Dejsakultorn, Chalermlok. "Discretionary use of open briefings in the Australian continuous reporting environment". Thesis, Queensland University of Technology, 2012. https://eprints.qut.edu.au/54623/1/Chalermlok_Dejsakultorn_Thesis.pdf.

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The Australian Securities Exchange (ASX) listing rule 3.1 requires listed companies to immediately disclose price sensitive information to the market via the ASX’s Company Announcements Platform (CAP) prior to release through other disclosure channels. Since 1999, to improve the communication process, the ASX has permitted third-party mediation in the disclosure process that leads to the release of an Open Briefing (OB) through CAP. An OB is an interview between senior executives of the firm and an Open Briefing analyst employed by Orient Capital Pty Ltd (broaching topics such as current profit and outlook). Motivated by an absence of research on factors that influence firms to use OBs as a discretionary disclosure channel, this study examines (1) Why do firms choose to release information to the market via OBs?, (2) What are the firm characteristics that explain the discretionary use of OBs as a disclosure channel?, and (3) What are the disclosure attributes that influence firms’ decisions to regularly use OBs as a disclosure channel? Based on agency and information economics theories, a theoretical framework is developed to address research questions. This theoretical framework comprises disclosure environments such as firm characteristics and external factors, disclosure attributes and disclosure consequences. In order to address the first research question, the study investigates (i) the purpose of using OBs, (2) whether firms use OBs to provide information relating to previous public announcements, and (3) whether firms use OBs to provide routine or non-routine disclosures. In relation to the second and third research questions, hypotheses are developed to test factors expected to explain the discretionary use of OBs and firms’ decisions to regularly use OBs, and to explore the factors influencing the nature of OB disclosure. Content analysis and logistic regression models are used to investigate the research questions and test the hypotheses. Data are drawn from a hand-collected population of 1863 OB announcements issued by 239 listed firms between 2000 and 2010. The results show that types of information disclosed via an OB announcement are principally on matters relating to corporate strategies and performance and outlook. Most OB announcements are linked with a previous related announcement, with the lag between announcements significantly longer for loss-making firms than profitmaking firms. The main results show that firms which tend to be larger, have an analyst following, and have higher growth opportunities, are more likely to release OBs. Further, older firms and firms that release OB announcements containing good news, historical information and less complex information tend to be regular OB users. Lastly, firms more likely to disclose strategic information via OBs tend to operate in industries facing greater uncertainty, do not have analysts following, and have higher growth opportunities are less likely to disclose good news, historical information and complex information via OBs. This study is expected to contribute to disclosure literature in terms of disclosure attributes and firm characteristics that influence behaviour in this unique (OB) disclosure channel. With regard to practical significance, regulators can gain an understanding of how OBs are disclosed which can assist them in monitoring the use of OBs and improving the effectiveness of communications with stakeholders. In addition, investors can have a better comprehension of information contained in OB announcements, which may in turn better facilitate their investment decisions.

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24

Mello, José Henrique Fortes. "Efeitos do controle da jaqueira, Artocarpus heterophyllus L., sobre a comunidade de pequenos mamíferos e a rede de dispersão de sementes na Ilha Grande, RJ". Universidade do Estado do Rio de Janeiro, 2012. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=3490.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Atualmente observa-se uma expressiva perda de biodiversidade global resultante de atividades antrópicas, sendo a introdução de espécies exóticas uma das mais impactantes. A jaqueira Artocarpus heterophyllus é uma espécie exótica introduzida no Brasil durante o período colonial, sendo considerada invasora em diversas localidades. Na Mata Atlântica invade áreas de mata aberta e de borda, habitualmente associadas a ambientes antrópicos. Na Ilha Grande é encontrada em grande abundância em decorrência do histórico de ocupação humana. Para compreender como a mastofauna responde a presença da jaqueira, o Laboratório de Ecologia de Mamíferos da Universidade do Estado do Rio de Janeiro (UERJ) vem desenvolvendo um estudo ao longo de seis anos nos arredores da Vila Dois Rios, localizada na face oceânica da Ilha Grande. A partir dos resultados prévios iniciou-se uma segunda etapa do estudo no mesmo local que buscou avaliar diferentes métodos de controle das jaqueiras. O presente estudo é uma continuação direta desses dois trabalhos anteriores e teve como objetivo acompanhar as respostas da comunidade de pequenos mamíferos no período imediatamente posterior ao controle. Durante 18 meses foram amostradas bimestralmente 18 grades, 10 aonde foi efetuado o controle das jaqueiras e 8 aonde não foi constatada a presença desta árvore. Em cada grade foram colocadas 11 armadilhas de captura viva sendo banana a isca utilizada. Os mamíferos capturados foram medidos e suas fezes coletadas. A quantidade de jacas em cada área também foi anotada bimensalmente. As fezes foram analisadas em laboratório e as sementes encontradas identificadas. Os resultados obtidos indicam que a influência de A. heterophyllus sobre a estrutura da comunidade de pequenos mamíferos foi menor após o tratamento de controle. A única espécie que parece ainda responder a abundância de jaqueiras é o roedor Trinomys dimidiatus, que apresentou densidades mais elevadas nas áreas em tratamento, porém mais próximas a resultados obtidos para espécies congêneres em áreas pouco antropizadas. Utilizando uma abordagem de redes complexas observamos que, embora T. dimidiatus seja a espécie mais abundante em termos de número de indivíduos, o gambá Didelphis aurita parece ser a espécie de mamífero mais importante para dispersão de sementes nativas, aparecendo como espécie com maior número de conexões com espécies de sementes nas redes contruídas para as áreas sem jaqueiras e com jaqueiras antes e após o tratamento. Finalmente, a partir dos dados obtidos criamos um modelo matemático para a população de T. dimidiatus dos arredores da Vila Dois Rios, baseado em um crescimento logístico. Os resultados do modelo proposto se mostraram correlacionados com os dados de abundância reais, de modo que ele parece ser um simulador adequado da população local.
Currently, the world is experiencing a severe loss of biodiversity as consequence of human activities. Of these, the introduction of exotic species is one of the most harmful. The jackfruit tree, Artocarpus heterophyllus, is considered an exotic species in Brazil, where it was introduced during colonial times. In the Brazilian Atlantic Rainforest, A. heterophyllus colonizes open canopy and edge areas, mostly associated with anthropic environments. In Ilha Grande it can be found in high densities as a result of the historical process of human occupation of the island. To better understand if and how the small mammalian fauna responded to the presence of A. heterophyllus, the Laboratory of Mammal Ecology of Universidade do Estado do Rio de Janeiro (UERJ) has been developing a study in the course of the last six years in the surroundings of Vila Dois Rios, located in the oceanic front of Ilha Grande. Based on previous results, a second phase of the study was implemented in the same local. This second study aimed to evaluate the best control method for the jackfruit trees (Moura 2011). The present study is a direct continuation of both studies, its main objective being to accompany the responses of mammalian community in the period immediately after the treatment of the jackfruit trees. During the course of 18 months 18 grids were sampled in a bimonthly basis, 10 where the jackfruit trees were treated and 8 where jackfruit trees were absent. In each grid 11 live traps were opened, and the bait was banana. The captured mammals were ear-tagged and measured and their feces collected. The number of jackfruits was also counted in each area bimonthly. The feces were analyzed in laboratory and the found seeds identified. Our results indicate that the community structure is being less influenced by A. heterophyllus abundances after the control treatment. The only species that still presented a response to the presence of A. heterophyllus was the spiny rat Trinomys dimidiatus. Even so, although the density of T. dimidiatus was high, it was lower than the density found previously, being more similar to results obtained for congeneric species in less anthropized sites. By using complex network analysis we observed that, although T. dimidiatus is the most abundant species in the study area, the opossum Didelphis aurita seems to be the most important species in terms of seed dispersal. D. aurita was the species with most connections in all built networks for areas without jackfruit trees and with jackfruit trees before and after the treatment. Finally, based on the obtained results we created a mathematical model for T. dimidiatus population of the surroundings of Vila Dois Rios, based on the logistic growth equation. The results of the proposed model were statistically correlated with our actual data, and so may be considered an adequate simulator for this particular population.

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Timén, William. "The logistical secret : Supply Chain Management in the Dominican Republic". Thesis, Södertörns högskola, Institutionen för samhällsvetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-19919.

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Globalisation has made logistics more important than ever in developing countries. If one business function raises their costs on a service, the end customer will usually pay the price in the store. When the end customers cannot afford the end price on a product, they will turn to other alternatives. This thesis examines how process management would affect the local population within the Dominican Republic. By beginning to question why some functions exist the effect will be economically visible in a DuPont according to the theories. Supply chain management seeks to manage the whole processes from A to Z in the most efficient way possible. The study was conducted during 8 weeks in the Dominican Republic. Eleven managers were interviewed to see how important SCM is for DR. The conclusions of the study is that Supply Chain Management is very important for DR. Well managed supply chains allow higher quality goods such as medicine and food to be accessed at a lower price by the local population. By targeting the economical position of working capital in a process an organisation can reach an increased ROI without the use economical means (increase the income/delivery service or reduce the costs).
MFS study financed by the Swedish International Development cooperation Agency, SIDA

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Karlsson, Olof y Anton Nilsson. "Effekter av tillväxt genom ett informationslogistiskt perspektiv : En studie som belyser ett tillverkande företags expansiva tillväxt och transporter". Thesis, Linnéuniversitetet, Institutionen för informatik (IK), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-85967.

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Många företag har under de senaste åren haft en god tillväxt inom deras organisationer som har påverkat både företagets interna och externa organisationsstruktur. Det som främst har påverkat företagen är globaliseringen då de geografiska gränserna har suddats ut, vilket har lett till att efterfrågan på produkter har ökat vilket ökar även kraven på transporterna. Tidigare forskning belyser att vid tillväxtperioder ökar företagens transportkostnader markant och kräver därför en ökad kontroll över dessa kostnader. Studiens valda teoretiska ramverk har använts för att identifiera och visuellt belysa de informationslogistiska effekterna av tillväxt. Syftet med studien har varit att utifrån ett informationslogistiskt perspektiv undersöka ett tillverkande företags effekter under en period av expansiv tillväxt med avgränsning till transporter. Studiens forskningsfrågor har besvarats med hjälp utav en kvalitativ metod med semistrukturerade intervjuer för att samla in empiri. Den insamlade empirin har analyserats genom tre olika tillvägagångssätt som är beskrivning, systematisering och kategorisering samt tagit det etniska övervägandet i beaktning. Resultatet av studien har påvisat att det administrativa arbetet på fallföretaget inte har prioriterats under en tillväxtperiod. Det har lett till att organisationen har fått en okontrollerad informationshantering. Genom det framtagna teoretiska ramverket TOEI, kunde resultatet analyseras och identifiera de informationslogistiska effekterna i de fyra huvudkategorierna teknik, organisation, miljö och individ. Det visade på att fallföretaget har påverkats av den snabba tillväxten och det kan bekräftas att riskfaktorerna av tillväxt är informationsöverflöd, ökade arbetsuppgifter, tidsbrist samt okontrollerade kostnadsunderlag.
Many companies have experienced growth within their organizations over the past fewyears, which has influenced these companies’ internal and external organizational structure.Companies have been affected by globalization since the geographical boundaries have been erased, which has led to an increase in demand for products and transportationrequirements. Previous research shows that there is a significant increase in a company’stransportation costs during periods of growth, which therefore requires an improved control over these costs. Based on the purpose of the research was to find a suitable and theoretical framework in order to identify and visually highlight the Information logistics’ effects by growth. The purpose of this research was to investigate and explore the effects of expansive growth during a specific period of time and how that effects a manufacturing company through an Information logistics perspective, with limitation to transport. The research in this study has been answered with the help of a qualitative method in which semi-structured interviews have been used to collect empirical data. Then this data has been analyzed through the three different approaches which is description, systematisation and categorization and the answers are handled ethically. The result of the case study showed that the administrative work has not been prioritized during a period of growth. Through the developed theoretical framework TOEI, the result has been analyzed and the Information logistics’ effects could be identified in the four main categories technical, organizational, environmental and individual. The case study concluded that companies affected by rapid growth experience the following risk factors: information overflow, increasing work assignment, lack of time and uncontrolled cost support.

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Li, Hongqin. "Leading, knowing and growing from a Wu Wei perspective : a study of logistics SMEs in Shanghai, China". Thesis, University of Exeter, 2015. http://hdl.handle.net/10871/24171.

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The aim of the study is to investigate how owner-managers of Chinese SMEs explore and exploit knowledge while growing SMEs in the spirit of Wu Wei. SME growth has been an increasingly important topic, where there is an important link between SME leadership, knowledge and growth. However, a large body of existing research treats knowledge as a static or reified asset or resource such that these studies are mainly concerned with how to create, acquire, transfer or manage knowledge. Following that, the research methods tend to be dominated by quantitative analysis, and weighs towards large organizations in developed economies. Drawing on the data collected in China, this study employs a mixed-methods approach by administering 103 surveys, wherefrom nine owner-managers are isolated for in-depth interviews at three business stages of SMEs (micro, small and medium). By attending to three dimensions (genuine Wu Wei, You Wei and Wu Bu Wei) of a Chinese Daoist Wu Wei perspective, it re-examines the link between SME leadership, knowledge and firm growth. This empirically-derived work shows evidence of subtle changes embedded in the growing process: While owner-managers stress keeping inherent openness to explore knowledge (genuine Wu Wei) and strategically exploit knowledge deployed in their everyday leadership practice (You Wei), growth evolves as a spontaneous and continuous accomplishment (Wu Bu Wei). By adopting a Wu Wei perspective, this study makes distinctive contributions to the understanding of leadership, knowledge and growth, where leadership and knowledge co-evolve and disseminate in the dynamic processes of growing as ‘leadership becoming’ rather than ‘knowledge leadership’. Whilst fostering the co-flow and co-evolution of leading, knowing and growing, the owner-managers undertake the role of knowledge generalist, knowledge supervisor and knowledge mentor within micro, small and medium firms.

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Sabanovic, Aida, Gustav Behnke y William Chan. "Logistiska problem vid e-handelns tillväxt : En flerfallsstudie av svenska e-handelsföretag". Thesis, Linnéuniversitetet, Institutionen för ekonomistyrning och logistik (ELO), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-27693.

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Bakgrund: E-handel har haft en ständig ökning i Sverige sedan de första företagen startade sina verksamheter. Under de senaste åren har e-handeln visat en betydligt större tillväxttakt än detaljhandeln. Statistik visar att nio av tio konsumenter någon gång har e-handlat vilket tyder på att e-handeln idag är väletablerat bland konsumenterna. En mognare marknad har lett e-handeln in i en ny fas i den konkurrenskraftiga expansionen. Med en expanderad e-handel tillkommer nya utmaningar och problem inom logistik. E-handelsföretag som inte infört nödvändiga logistiksatsningar riskerar att hindras i utvecklingen eller konkurreras ut. Detta innebär att företag inom e-handel måste optimera, förnya och bli mer personliga mot kund för att behålla ett övertag gentemot konkurrenterna. Syfte: Syftet med rapporten är att beskriva inköpsprocessen och lagerhanteringen samt undersöka vilka problem inom inköpsprocessen och lagerhanteringen svenska e-handelsföretag upplevt i samband med e-handelns tillväxt. Metod: Rapporten består av en kvalitativ flerfallstudie. Studien utfördes på fallföretagen NordicFeel, NordicInk, Sporttema, Bubbleroom och GreenTech. Datainsamling har skett genom litteraturstudier, semi-strukturerade intervjuer samt direkta observationer. Slutsats: Svenska e-handelsföretag i studien är små i förhållande till sina leverantörer. Därmed avviker de från van Weeles (2010) inköpsprocess då de inte tillämpar kontraktskrivning och leverantörsuppföljning. Eftersom samtliga fallföretag bedriver försäljning av befintliga varumärken begränsas även deras möjlighet att utfärda specifikationer till leverantörer. Studier av lagerhanteringen uppvisades att samtliga fallföretag utför ankomstkontroll på inkommande gods. Dock levereras godset i- 4 -avvikande förpackningar och på olika pallsystem, vilket medför varierande hantering vid inläggning och plock av produkterna. Avsaknad av kontraktskrivning medför att samtliga företag har svårt att kräva leverantörer på ersättning vid felaktiga leveranser. Felaktiga leveranser härrör från att de är ofullständiga eller innehåller felförpackade produkter. Vid mottagning upptäcker företagen skadade produkter, som rapporteras till inköpsavdelningen. Samtliga företag utnyttjar inte sin lageryta optimalt, vilket leder till försvårad framkomlighet på lagret vid inläggning och plock.
Background: E-commerce has had a constant increase in Sweden since the first companies started their operations. In recent years, e-commerce has shown a significantly higher growth rate than retail. Statistics show that nine out of ten consumers have shopped online, suggesting that e-commerce is well established among consumers. A mature market has led e-commerce in to a new phase of the comtetitive expansion. With an expanded e-commerce however, new logistical challenges and problems emerge. E-commerce companies that have not yet adopted necessary logistics efforts could be hindered in their development or forced to exit the market. This means that companies in e-commerce must optimize, innovate and be more personal with customers in order to maintain an edge over the competition. Purpose: The purpose of this paper is to describe the purchasing process and inventory management and study the problems in the purchasing process and inventory management Swedish e-commerce companies experienced in e-commerce growth. Method: The paper consists of a qualitative multiple case study. The study was performed on the companies NordicFeel, NordicInk, Sporttema, Bubbleroom and GreenTech. Data was obtained from literature reviews, semi-structured interviews and direct observations. Conclusion: Swedish e-commerce companies in the study are small in relation to their suppliers. The companies differ from van Weeles (2010) purchasing process since they do not apply contracts and supplier monitoring. Because the companies engage in sales of existing brands they are also limited in their ability to issue specifications for suppliers. The studies of inventory management demonstrated that the companies perform inspection of incoming goods. However, the delivered goods are received in- 6 -different packaging and different pallet systems, which results in varying handling during insertion and retrieval of the products. The lacks of contracts mean that the companies have difficulty to demand suppliers of compensation due to incorrect deliveries. Incorrect deliveries mean they are incomplete or contain improperly packaged products. Upon receiving damaged products, the companies report to the purchasing department. The companies do not use the warehouse space optimally, leading to a more cumbersome accessibility in the warehouse during loading and picking.

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Munim, Ziaul Haque y Hans-Joachim Schramm. "The impacts of port infrastructure and logistics performance on economic growth: the mediating role of seaborne trade". SpringerOpen, 2018. http://dx.doi.org/10.1186/s41072-018-0027-0.

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Considering 91 countries with seaports, this study conducted an empirical inquiry into the broader economic contribution of seaborne trade, from a port infrastructure quality and logistics performance perspective. Investment in quality improvement of port infrastructure and its contribution to economy are often questioned by politicians, investors and general public. A structural equation model (SEM) is used to provide empirical evidence of significant economic impacts of port infrastructure quality and logistics performance. Furthermore, analysis of a multi-group SEM is performed by dividing countries into developed and developing economy groups. The results reveal that it is vital for developing countries to continuously improve the quality of port infrastructure as it contributes to better logistics performance, leading to higher seaborne trade, yielding higher economic growth. However, this association weakens as the developing countries become richer.

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Koenigs, Leslie E. (Leslie Erin) 1973. "A "go to market" strategy : enabling P&G profitable share growth through streamlined logistics". Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/34721.

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Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering; in conjunction with the Leaders for Manufacturing Program at MIT, 2002.
Includes bibliographical references (leaf 75).
The cosmetics industry is an intensely competitive, fashion-driven industry. As such, new product launch processes are viewed to be a competitive advantage in promoting continued brand awareness in the market place. However, very few resources are in place to encourage manufacturer and retailer collaboration and to monitor new product launches during launch and after the initial 3-6 month promotion period. As a result, large trade inventories and product return charges negatively impact both the profitability of the manufacturer, Procter & Gamble (P&G), as well as their retail customers. This thesis concentrates on supply chain management methods to enhance the profitability of launching new products in the cosmetics industry to both P&G and one retail customer, Retailer A. Of the retailers that P&G sells cosmetics through, Retailer A represents one of the largest opportunities to reducing trade inventory and product return charges. An analysis presented in this thesis revealed that Retailer A ordered an average of 18 months of a new product during the first 2-3 months of launch for products released in the January 2000- May 2001 period. Research was conducted during a six and a half month internship within P&G's Product Supply group at the Cosmetics Division in Hunt Valley, MD. The internship was affiliated with the Massachusetts Institute of Technology's Leaders for Manufacturing Program. Outputs of this work include a high-level strategy for launching new products within this division, as well as logistics tactics developed via a dynamic supply chain model. Through theoretical and simulation analysis, the project revealed that implementing unique stocking and reordering strategies for launching new products based on item type and retail store sales volume results in significant savings to P&G and Retailer A. For Retailer A alone, the impact of implementing the project recommendations is estimated to be approximately a one million dollar reduction in final retail inventory, which translates into between a half a million and a one million dollar reduction in P&G's product return charges. In addition, an in-stock improvement opportunity is estimated to be one hundred and thirty thousand dollars, translating directly to improved service for the final consumer.
by Leslie E. Koenigs.
S.M.
M.B.A.

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Filho, DemÃcrito Pereira GalvÃo. "CaracterizaÃÃo dos operadores logÃsticos atuantes no Estado do CearÃ: empresas, mercados e atividades desenvolvidas". Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14161.

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nÃo hÃ
Na conjuntura econÃmica atual, as organizaÃÃes, em busca de maior eficiÃncia e de vantagens competitivas sustentÃveis que lhes garantam crescimento no longo prazo, tÃm concentrado esforÃos em suas competÃncias principais, terceirizando as demais atividades da empresa, entre elas, as da logÃstica, o que levou ao surgimento e desenvolvimento do mercado de Operadores LogÃsticos (OLs). Esta dissertaÃÃo teve como objetivo principal caracterizar os OLs atuantes no Estado do CearÃ em termos de identificaÃÃo e dimensionamento das empresas, das atividades logÃsticas realizadas e do desenvolvimento desse mercado. Para tanto, este trabalho assumiu uma natureza exploratÃria-descritiva, se utilizando do mÃtodo indutivo e do estudo de casos mÃltiplos, envolvendo a consulta de dados secundÃrios disponÃveis em periÃdicos e publicaÃÃes especializadas em logÃstica, bem como tambÃm a livros, dissertaÃÃes e teses jÃ produzidas, alÃm dos dados obtidos em visita aos sites das empresas objeto desta pesquisa. Como objetivo secundÃrio, o presente estudo buscou, atravÃs de pesquisa bibliogrÃfica, descrever e discutir os principais conceitos da logÃstica e sua importÃncia para a economia das empresas, caracterizar os OLs, enfatizando os principais conceitos e a evoluÃÃo dessas empresas no Brasil e avaliar alguns aspectos econÃmicos do mercado de OLs. Os resultados das anÃlises revelam um segmento formado por empresas relativamente jovens, em sua maioria de grande porte, mas que registram taxas positivas de crescimento, possivelmente decorrentes do grande nÃmero de serviÃos prestados, do uso intensivo da tecnologia e do fechamento de novos contratos, favorecido pelo crescimento das atividades nos diferentes setores econÃmicos do paÃs em 2010. Concluiu-se ainda, que os OLs prestam serviÃos aos mais variados tipos de indÃstria e que com polÃticas pÃblicas corroborando para minimizar problemas histÃricos no paÃs como a deficiÃncia de infraestrutura, carga tributÃria e trÃmites excessivamente burocrÃticos, poderia ser celebrado um expressivo crescimento econÃmico para o Estado do CearÃ.
In the current economic climate, organizations, seeking greater efficiency and sustainable competitive advantages that will ensure long-term growth, efforts have concentrated on its core competencies, outsourcing other business activities, including the logistics, which led to the emergence and development of markets for Logistics Operators (OLs). This work aimed to characterize the OLs active in the state of Ceara in terms of identifying and sizing of companies, logistic activities undertaken and the development of this market. Therefore, this study took an exploratory-descriptive, if using the inductive method and the study of multiple cases involving the consultation of secondary data available in journals and publications specializing in logistics, as well as well as books, dissertations and theses ever produced in addition to the data obtained to visit the websites of the companies object of this research. As a secondary objective, this study sought, through literature, describe and discuss the main concepts of logistics and its importance to the economy of enterprises, to characterize the OLs, emphasizing the key concepts and evolution of these companies in Brazil and assess some economic aspects OLs market. The analysis results show a segment comprised of relatively young companies, mostly large, but that record positive growth rates, possibly due to the large number of services, the intensive use of technology and the closing of new contracts, favored the growth of activities in different economic sectors in the country in 2010. It was also concluded that the OLS provide services to a range of industry and supporting public policies to minimize the historical problems in the country and the deficiency of infrastructure, taxes and overly bureaucratic procedures, could be entered into a significant economic growth for State of CearÃ.

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Cheng, Raymond Wai Man. "The determinants of growth in small and medium enterprises: an empirical study in the logistics industry in Hong Kong". Thesis, Curtin University, 2006. http://hdl.handle.net/20.500.11937/59.

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Small and Medium Enterprise (SMEs) have contributed significantly to the economic growth of Hong Kong and it is worth investigating how they prosper. This study was based on an examination of a sample of SMEs in the logistics industry operating during the economic crisis in Hong Kong. The factors influencing the growth of small firms are many, complex and erratic. The primary objective of this study was to test the determinants of SME growth. The research question addressed was how and to what extent the characteristics of the owner-manger, the nature of the firm, and company strategy, together with the economic and government factors, impact upon the growth of small business. This study was conducted in 2004, based on a survey of 102 SMEs within the logistics industry in Hong Kong SAR. By studying the factors contributing to the growth of SMEs, this research investigated and analyzed the characteristics of SMEs which were at least three years old during of the period 1998 - 2003. The appropriateness and the support of the determinants that affect SME growth were empirically analysed. The research design was quantitative in nature, testing various hypotheses and theories about the associations between perceived constructs. Outcomes were then compared with factual indicator data, subjected to multiple regression analysis and co-efficiency analysis. The results of the regression analysis showed no tremendous incongruity compared to research conducted in previous studies, although there were some factors associated significantly and some factors associated positively but insignificantly with firm growth. Even though some findings appeared to be inconsistent with previous studies, the preoccupation of researchers and policy-makers worldwide with matters relating to SME growth was recognized.These empirical findings provide evidence that owner-managers may adopt different managerial styles and strategies as a consequence of the amount of growth desired, and the amount of risk they are willing to assume. Of the four main factors identified as influencing the growth of small firms - the characteristics of the owner-manager, the nature of the firm itself, the business strategies adopted, and the external factors concerned - all these four components need to be combined appropriately for growth to be achieved. This means that it is very difficult to identify whether or not a firm will be a success or a failure. The significances of these factors and their impacts have been addressed and reported in the study. Recommendations are made for business practitioners who are still trading, distinguishing between businesses with high and low growth expectations. Owner-managers are encouraged to acquire better management skills and qualifications to improve their managerial capabilities and experience. Appropriate strategic planning, technology advancement, education, training and government support are recommended for improving growth performance. In recognition of the need to improve small business growth, these research findings reveal that some of the factors considered important to success in Hong Kong small businesses are unique to the Hong Kong business environment. In this sense, the findings provide good references for scholars and policy-makers to design policies and provide assistance that are appropriate for use particularly in Hong Kong. Future research directions have been discussed and managerial implications for both practitioners and researchers have been suggested.

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Karlsson, Emma y Sandra Widen. "The possibility of an increased utilization of harvested biomass in Östergötland: Optimization and analysis of flows". Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-150141.

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I studien har resurstillgången i form av biomassa inom Östergötland kartlagts för att undersöka om det finns en potentiell möjlighet för ett ökat tillvaratagande av skördad biomassa från skogsbruket. Det har även undersökts om ett tillvaratagande av biomassa för en ökad energiutvinning är ekonomiskt hållbart i förhållande till de rörliga transportkostnader som medförs. Utifrån den kartläggning som genomförts har därmed en matematisk modell skapats som ger förslag på hur biomassan skall fördelas från resurspunkter till värmeverk i Östergötlands 13 kommuner, för att därmed uppfylla den efterfrågan av fjärrvärme som finns i respektive kommun. Den matematiska modellen fördelar även ut de resurser som finns kvar efter att efterfrågan har uppfyllts, till ett antal optimalt placerade kondenskraftverk, där elektricitet skall utvinnas. Utifrån 4 framtagna scenarier tyder den matematiska modellens resultat på att ett ökat tillvaratagande av biomassa i form av grot och stubb kan genomföras med lönsamhet genom optimerad lokalisering av förbränningsstationer och fördelning av biomassa. Denna studie är en del av ett kommande forskningsprojekt och ger en första indikation på att det finns en potential för ett ökat tillvaratagande av biomassa från skogsbruket.

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34

Cheng, Raymond Wai Man. "The determinants of growth in small and medium enterprises: an empirical study in the logistics industry in Hong Kong". Curtin University of Technology, Graduate School of Business, 2006. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=18498.

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Small and Medium Enterprise (SMEs) have contributed significantly to the economic growth of Hong Kong and it is worth investigating how they prosper. This study was based on an examination of a sample of SMEs in the logistics industry operating during the economic crisis in Hong Kong. The factors influencing the growth of small firms are many, complex and erratic. The primary objective of this study was to test the determinants of SME growth. The research question addressed was how and to what extent the characteristics of the owner-manger, the nature of the firm, and company strategy, together with the economic and government factors, impact upon the growth of small business. This study was conducted in 2004, based on a survey of 102 SMEs within the logistics industry in Hong Kong SAR. By studying the factors contributing to the growth of SMEs, this research investigated and analyzed the characteristics of SMEs which were at least three years old during of the period 1998 - 2003. The appropriateness and the support of the determinants that affect SME growth were empirically analysed. The research design was quantitative in nature, testing various hypotheses and theories about the associations between perceived constructs. Outcomes were then compared with factual indicator data, subjected to multiple regression analysis and co-efficiency analysis. The results of the regression analysis showed no tremendous incongruity compared to research conducted in previous studies, although there were some factors associated significantly and some factors associated positively but insignificantly with firm growth. Even though some findings appeared to be inconsistent with previous studies, the preoccupation of researchers and policy-makers worldwide with matters relating to SME growth was recognized.
These empirical findings provide evidence that owner-managers may adopt different managerial styles and strategies as a consequence of the amount of growth desired, and the amount of risk they are willing to assume. Of the four main factors identified as influencing the growth of small firms - the characteristics of the owner-manager, the nature of the firm itself, the business strategies adopted, and the external factors concerned - all these four components need to be combined appropriately for growth to be achieved. This means that it is very difficult to identify whether or not a firm will be a success or a failure. The significances of these factors and their impacts have been addressed and reported in the study. Recommendations are made for business practitioners who are still trading, distinguishing between businesses with high and low growth expectations. Owner-managers are encouraged to acquire better management skills and qualifications to improve their managerial capabilities and experience. Appropriate strategic planning, technology advancement, education, training and government support are recommended for improving growth performance. In recognition of the need to improve small business growth, these research findings reveal that some of the factors considered important to success in Hong Kong small businesses are unique to the Hong Kong business environment. In this sense, the findings provide good references for scholars and policy-makers to design policies and provide assistance that are appropriate for use particularly in Hong Kong. Future research directions have been discussed and managerial implications for both practitioners and researchers have been suggested.

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35

Kury, Christian. "Epidermal growth factor receptor (EGFR) als mögliches neues Therapieziel bei vielen Tumortypen Einfluss von Nachweisverfahren auf Bedeutung und Logistik /". [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=97614820X.

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Kury, Christian. "Epidermal Growth Factor Receptor(EGFR) als mögliches neues Therapieziel bei vielen Tumortypen Einfluß von Nachweisverfahren auf Bedeutung und Logistik /". [S.l. : s.n.], 2004. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB12046075.

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Deonás, Nikolaos 1978. "Logistical and transportation infrastructure in Asia : potential for growth and development to support increasing trade with Europe". Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/29392.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2004.
Includes bibliographical references (leaves 133-139).
This thesis examines the implications of the rapid growth in demand for trade between Europe and Asia for the existing transportation network and logistical infrastructure. In general terms, technologies need to improve and be compatible with each other, multimodalism and interconnectivity of the various modes needs to be fully implemented, capacities have to grow, facility efficiencies need to improve, planning processes, and government policies need to be updated, along with the growth of demand in the region. The nature and extent of the required changes depend on the role of each country in the region, as well as the capabilities and utilization of the existing infrastructure. The methodology involves an ABC analysis that groups the Asian countries in three categories depending on their level of development and infrastructure. The major transportation modes (urban, road, rail, sea, and air), the logistical infrastructure and the importance and use of Information Technology are examined. Leading economies of the region, categorized as "A" countries, appear to be very successful and are highly competitive in global trade. Network optimization and high technology applications, such as Intelligent Transportation Systems and Electronic Data Interchange can improve these countries' use of infrastructure. Developing countries of the region, categorized as "B" countries, need to further implement best practices and attract funds for the development of their infrastructure.
(cont.) Their needs include further development of the transportation network and integration of all the modes in order to assist their economy and global positioning. "C" countries have inadequate or non- existent infrastructure. These countries need to build or expand their basic infrastructure in order to assist in the transportation of their own products and be able to communicate with the rest of the world. Moreover, international interests imply that these countries provide adequate regional networks that interconnect with those of their neighbors. Directions are provided for the steps that need to follow in the developmental process. Priorities and policy options are analyzed.
by Nikolaos Deonas.
S.M.

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38

Le, Vi. "Processus de branchement avec interaction". Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4743/document.

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Cette thèse se compose de quatre chapitres:Le chapitre 1 étudie la distribution du temps de coalescence (plus récent ancêtre commun) de deux individus tirés au hasard (uniformly) dans la génération actuelle d'un processus de Bienaymé-Galton-Watson en temps continu.Dans le chapitre 2, nous obtenons une représentation de la diffusion de Feller logistique en termes des temps locaux d'un mouvement brownien réfléchi H avec une dérive qui est affine en le temps local accumulé par H à son niveau actuel.Le chapitre 3 considère la diffusion de Feller avec compétition générale. Nous donnons des conditions précises sur le terme de la concurrence, pour le but de décider si le temps d'extinction (qui est aussi la hauteur du processus) reste borné ou non lorsque la taille initiale de la population tend vers l'infini, et de même pour la masse totale du processus.Dans le chapitre 4, nous généralisons les résultats du chapitre 3 pour le cas du processus de branchement à espace d'état continu avec compétition à trajectoires discontinues
This thesis consists of four chapters:Chapter 1 investigates the distribution of the coalescence time (most recent common ancestor) for two individuals picked at random (uniformly) in the current generation of a continuous time Bienaymé-Galton-Watson process.In chapter 2 we obtain a Ray-Knight representation of Feller's branching diffusion with logistic growth in terms of the local times of a reflected Brownian motion H with a drift that is affine in the local time accumulated by H at its current level.Chapter 3 considers the Feller's branching diffusion with general competition. We give precise conditions on the competition term, in order to decide whether the extinction time (which is also the height of the process) remains or not bounded as the initial population size tends to infinity, and similarly for the total mass of the process.In chapter 4 we generalize the results of chapter 3 to the case of continuous state branching process with competition which has discontinuous paths

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39

Ibrahim, Jacob y Andreas Karlsson. "Investering i Logistikfastigheter". Thesis, KTH, Fastigheter och byggande, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-146619.

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Denna uppsats kretsar kring beslutsfattande och metodik vid fastighetsinvesteringar i potentiella tillväxtnoder. Då fastighetssektorn är så omfattande har vi valt att avgränsa oss till en speciell typ av fastigheter, närmare bestämt logistikfastigheter. Ytterligare en fördjupning har skett, där vi valt ut en specifik investering i området, för att fördjupa oss om denna. Det specifika fall vi valt att ta mestadels av vår data från är Rosersbergs industriområde, även känt som Stockholm Nord Logistikcenter. Som en referenspunkt till Stockholm Nord Logistikcenter har vi i arbetet även skrivit översiktligt om Arenastaden, som är belägen i Solna. En del tidigare forskning har gjort på området Logistik, och somliga av dessa studier har vi även tagit del av för att utvinna information inom ämnet som även kunnat användas i vårt arbete. Dock har den studien vi främst använt oss av varit inriktad på logistik i sin helhet och inte ett specifikt fall. På cirka 9 år har området utanför Rosersberg villastad förvandlats från en skog, inom ett bullerområde utanför en mindre bostadsort, till en logistiknod där ett tiotal stora företag bedriver verksamhet i tusentals kvadratmeter lokaler. Allt detta i något som tros komma att bli ett av de största logistikcentrena i hela Sverige, och med tanke för de framtidsplaner som finns är det inte osannolikt. Den största drivkraften för projektet har varit Kilenkrysset, men detta med hjälp av gott samarbetsvilja från offentlig sektor. Vår studie kretsar kring vilka faktorer som påverkat till att denna investering blivit lyckad, samt vilken typ av företag det är som bedrivit arbetet. Vi har även gått in på hur orten Rosersberg, som tidigare legat i lä, påverkats av detta händelseförlopp. Innan projektet i Rosersberg initierades av Kilenkrysset har många frågor angående området diskuterats inom kommunen under många årtionden, dock har man aldrig kommit till skott på grund av bristande intresse och samhällsnytta. Utifrån det vi kunnat utläsa av den tillgängliga data vi samlat, har vi kunnat dra slutsatsen att utvecklingen bidragit till att göra platsen attraktiv för företag, men likväl för människor att numera bo i. Under arbetet har vi tagit kontakt med fyra respondenter som intervjuats, varav tre av dessa respondenter kommer från koncernen Kilenkrysset. Flera företag, bland annat NCC, har kontribuerat till utvecklingen i Rosersbergs industriområde, men Kilenkrysset är de som varit överlägset störst i området. Vi har även haft kontakt med en före detta anställd på bygg- och trafiknämnden i Sigtuna kommun för att få en objektiv, och mer överskådlig bild över hur samarbetet mellan offentlig sektor och investerare sett ut. För att bättre kunna förstå hur beslutsfattande skötts inom Kilenkrysset, både under och innan projektets fortgående, har vi studerat företaget mer grundligt. Information har framtagits kring företagets uppstart och dess historia, och hur det beslutsfattandet som till sist ledde dem till Rosersberg sett ut. Man kan klart se att både företaget i sin helhet och dess ledning är säregna, vilket man även ur materialet kan observera hur detta gynnat dem under projektets fortlöpande. Men även negativa aspekter har tagits upp angående deras beslutsfattande och tillvägagångssätt. Detta för att ge en rättvisande bild av vilka för- och nackdelar som i realiteten kretsar runt dessa metoder.
This essay revolves around the desicion making process in real estate investments, where the investment contributes to the economic growth of the surrounding area. Due to the sheer size of the sector, we have chosen to limit our study to a specific type of real estate, which we decided to be logistic property. We have also chosen to study a specific case in more detail, to be able to understand how these projects develops. The case we chose was the investment of Rosersbergs Industrial park, also known as Stockholm Nord Logistic Centre. As a point of reference to this project we have chosen to briefly look into another, quite similar in size, project; Arenastaden in Solna. There have been studies made on Logistics in the past, some of which we have chosen to use as sources of information on our study. The study we used as the main source studied logistics on a different scale than ours, where the whole logistics market in Stockholm was studied. In merely 9 years the area surrounding Rosersberg has transformed, from unexploited land suffering from airport noise, into a rapidly growing logistics center where dozens of companies have chosen to exist. All this in an area many believe will be one of the biggest logistic centers in Sweden, which is not unlikely due to the future plans of the area. The company that initiated the project, which also has been the driving force is Kilenkrysset AB, with a lot of assistance from a supportive municipality. Before the company's initiative in the area, the municipality has been contemplating since the 60's what to do with the area, and how to make it grow. The issue before the company came along was almost solely economical; because there was no solid plan or investor to take care of the area and the infrastructure surrounding it. Based on the data we collected the area has improved its attraction both to companies, as well as to the residents in the area. Our study will attempt to determine which of the variables had the greatest importance on the end result of the project. As well as to study which type of company that decides to take on these kinds of projects. We have also studied how the surrounding area in Rosersberg has grown as a result of this specific investment. To gather information on the subject, we have contacted four respondents, which consists of three people from the Kilenkrysset organization. The reason why the majority of the interviewed respondents has been from one single company is because they have by far been the biggest investor in the area. The construction company NCC has also been part of the development in the area, but have sold most of their property to Kilenkrysset. The last respondent is from the building and traffic department within the municipality (Bygg- och trafiknämnden). Since we want to understand how decision making is handled within these types of organizations, we have chosen to study Kilenkrysset more thoroughly. Information about their history and the decision making process that eventually lead them to Rosersberg. From the information collected we can conclude that the company and its management have quite an extraordinary way of doing business. It is also obvious how their way of thinking has benefited them throughout their project in Rosersberg. But every technique has consequences, and we will also enlighten these consequences to try to observe both the pros and the cons about these methods.

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40

Ricciardelli, Filippo. "Gestione di una base dati per la mappatura e l’ottimizzazione di processi logistici di una filiera agroalimentare". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.

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La tesi si prefigge di realizzare uno studio su una filiera agroalimentare attraverso un'ampia analisi iniziale e una successivo processo di ottimizzazione. Gli obiettivi riguardano la riduzione di due elementi chiave: - i costi di trasporto inter-nodo - le emissioni si Co2eq relazionate alle food miles I metodi implementati per ottere tali risultati sono stati: -uso del Location Allocation Problem -uso di una base dati fornita dal Centro distributivo committente -interfacciamento tra la base dati e il software di modellazione Il processo si articola in una descrizione accurata del modello creato e dei vari software sfruttati, per poi virare verso una chiara e precisa presentazione dello stato attuale della catena (as-is). Qui, per le 4 tipologie di nodo indagate, vengono studiati diversi elementi. Per citarne alcuni: 1) merce movimentata 3) differenze ingressi/uscite 4) numero di interazioni 5) kg medi trasportati 6) etc. Inoltre, sempre nello stato AS-IS, si presenta uno studio sul posizionamento dei nodi attuato sfruttando la funzione MAPPE di Excel e aiutandosi con svariati grafici. Viene calcolato poi il quantitativo totale di inquinamento differenziato per categoria e il costo totale. Nello stato ottimizzato i parametri del modello vengono individuati sfruttando tecniche euristiche e metodi legati al buon senso. I vari parametri e vincoli vengono poi caricati sul software AMPL che elabora e restituisce i risultati dell'ottimizzazione. L'analisi to-be viene presentata in contrapposizione allo stato attuale della catena, evidenziando miglioramenti e riduzioni implementate. Anche in questa circostanza si sfruttano grafici e tabella per chiarificare i procedimenti svolti. Il risultato dell'analisi consiste in una forte riduzione dei costi attraverso un imponente ricollocamento dei flussi sfruttando le potenzialità già insite nel sistema. I traguardi ottenuti sulla riduzione delle emissioni sono sempre collegabili al processo di ricollocazione dei flussi.

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41

De, Bod Anneke. "South Africa's freight transport involvement options in Sub-Saharan Africa : declining infrastructure and regulatory constraints". Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/1622.

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Silva, Marilia Ribeiro da. "Arranjos Produtivos De Turismo Com InserÃÃo Da LogÃstica De ServiÃo Visando O Desenvolvimento Local EndÃgeno: Estudo Do Caso De Guaramiranga". Universidade Federal do CearÃ, 2008. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=3435.

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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
Na atual conjuntura do Estado do CearÃ, marcada pelas conseqÃÃncias de um modelo de crescimento econÃmico com Ãnfase na industrializaÃÃo urbana concentrada na RegiÃo Metropolitana de Fortaleza (RMF), faz-se necessÃria a inclusÃo das demais regiÃes do Estado e de suas respectivas populaÃÃes. TambÃm, Ã necessÃria a desconcentraÃÃo da renda gerada pela atividade econÃmica, que beneficia uma parte mÃnima da populaÃÃo do Estado. Assim, a utilizaÃÃo de estratÃgias de desenvolvimento endÃgeno Ã imprescindÃvel. Nesse contexto, destaca-se o turismo que, no CearÃ, apresenta inÃmeras possibilidades advindas do clima, da localizaÃÃo geogrÃfica privilegiada e da diversidade de paisagens â serranas, litorÃneas e sertanejas, contemplando de forma equilibrada todas as regiÃes do Estado. Entretanto, para que o turismo gere benefÃcios para a populaÃÃo local, devem-se adotar formas de desenvolvimento, que sejam, de fato, economicamente includentes. Ã nesse cenÃrio, que se destacam os Arranjos Produtivos Locais TurÃsticos â APLTÂs que podem ser utilizados como estratÃgias de desenvolvimento local desde que a populaÃÃo seja realmente integrada. Todavia, para que tais arranjos se sustentem Ã necessÃria uma boa prestaÃÃo de serviÃos, pois o turismo Ã uma atividade que exige elevado grau de qualidade dos serviÃos ofertados. Nesse sentido, conceitos de logÃstica aplicados aos serviÃos turÃsticos podem servir como instrumentos para que esses serviÃos sejam adequadamente ofertados e de acordo com as expectativas dos clientes, visando Ã sustentabilidade dos atores locais, especificamente os proprietÃrios dos estabelecimentos de alojamento e de alimentaÃÃo que residem no municÃpio. Para isso, buscou-se a aplicaÃÃo de uma relevante proposta de indicadores de desempenho logÃstico para tais estabelecimentos turÃsticos. Ã, assim, que, nesta dissertaÃÃo, apresenta-se uma anÃlise do APLT com apoio da logÃstica como forma de impulsionar o desenvolvimento local endÃgeno, tendo como estudo de caso o MunicÃpio de Guaramiranga. Os resultados mostram, sinteticamente, uma baixa participaÃÃo e inter-relaÃÃo dos atores locais, alÃm de uma negativa avaliaÃÃo dos serviÃos ofertados pelos estabelecimentos estudados.
At the current framework in the State of CearÃ, characterized by the consequences of a model of economic growth giving emphasis on the urban industrialization concentrated on the Metropolitan Region of Fortaleza (MRF), it is necessary to include other regions of the state and their respective populations. Also, we must decentralize the income generated by the economic activity, which favors only a small m share of the stateâs population. Therefore, the use of strategies for endogenous development is essential. In this context, tourism stands out, which in CearÃ presents numerous opportunities due to our weather, the privileged geographical location and diversity of landscapes - mountains, seaside and countryside, covering all of the stateâs regions in a balanced way. However, in order for tourism to generate benefits for the local population, we must adopt forms of development which are really economically includent. It is in this scenario that the Tourism Local Productive Arrangements â TLPAâs stand out, which can be used as strategies for local development provided that population is really integrated. However, so that such arrangements are sustainable, support is needed to provide good services, as tourism is an activity that requires a high degree of quality of the services offered. In this sense, concepts of logistics applied to tourism services can serve as instruments so that such services are provided adequately and according to customersâ expectations, aiming at the sustainability of local actors, more specifically the owners of accommodation places and restaurants living in the town. For this reason, it was done a survey of excellent proposal of pointers of logistic performance for such tourist establishments. Therefore, we present in this Masterâs thesis an analysis of TLPAâs with the support of logistics as a way to foster local endogenous development, having as case study the City of Guaramiranga. The results has showed synthetically a low participation and interrelation of the local actors, beyond a negative evaluation of the services offered for the studied establishments.

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43

Macedo, Maxsuel de Moura. "Fluidez territorial e log?stica: o PAC no Rio Grande do Norte". Universidade Federal do Rio Grande do Norte, 2014. http://repositorio.ufrn.br:8080/jspui/handle/123456789/18975.

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Made available in DSpace on 2015-03-13T17:10:58Z (GMT). No. of bitstreams: 1 MaxsuelMM_DISSERT.pdf: 4624416 bytes, checksum: 0490a56bd282fc3dc15d7c3612fc0ede (MD5) Previous issue date: 2014-03-28
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
The state is responsible for creating regulatory and infrastructural conditions in a determined territory. These actions generate macrodynamics, however, in some cases they show selective and restricted, as in the case concerning the transportation sector. The actions of the Brazilian government aimed at territorial fluidity nowadays are evidenced especially by the Growth Acceleration Program (PAC). The PAC in the axes allocated to the transport sector, called logistics, which in turn appears as a pressing necessity and as an ideology of the current period. Therefore, within this context of territorial transformations resulting from this program we situate our work that aims to understand how the actions of the State implemented and planned under the PAC are configuring or can configure the brazilian territorial logistics, particularly in the state of Rio Grande do Norte
O Estado ? respons?vel por criar condi??es normativas e infraestruturais em um determinado territ?rio. Essas a??es geram macrodin?micas, contudo, em alguns casos elas se mostram seletivas e restritas, como no caso das concernentes ao setor de transporte. As a??es do Estado brasileiro destinadas a fluidez territorial na atualidade s?o consubstanciadas, especialmente, pelo Programa de Acelera??o do Crescimento (PAC). O PAC nos eixos destinados ao setor de transporte ? batizado de log?stica, que por sua vez, se apresenta como uma necessidade premente e como uma ideologia do atual per?odo. Portanto, dentro desse contexto de transforma??es territoriais advindas com esse programa situamos nosso trabalho, que objetiva compreender como as a??es do Estado concretizadas e planejadas no ?mbito do PAC est?o configurando ou podem configurar a log?stica territorial brasileira, particularmente, a do estado do Rio Grande do Norte

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44

Yang, Shih-Hui y 楊士慧. "A Logistic Growth Model for Social Networks". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/51119682336629306127.

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碩士
國立臺灣大學
資訊管理學研究所
99
With advance of Web 2.0 technology, many social networks such as Facebook, Twitter, and Digg, have been highly developed in recent years. Understanding the growth patterns and the characteristics of social networks helps us to promote the technology of running social networks, increase the networks’ value, and formulate marketing and pricing strategies. Therefore, in this thesis, we first utilize the concept of internal and external attractions to propose a population growth model. Next, we analyze the properties of the proposed model and show that the model has the characteristics of sale-free networks. Finally, we collect the data from two real world social networks to evaluate the proposed model. The experimental results show that these two social networks can be well fitted by the proposed model. Furthermore, we address the management implications of the proposed model and discuss how to promote the value of social networks.

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45

Clark, Aaron James. "Decline curve analysis in unconventional resource plays using logistic growth models". Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-08-4201.

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Current models used to forecast production in unconventional oil and gas formations are often not producing valid results. When traditional decline curve analysis models are used in shale formations, Arps b-values greater than 1 are commonly obtained, and these values yield infinite cumulative production, which is non-physical.. Additional methods have been developed to prevent the unrealistic values produced, like truncating hyperbolic declines with exponential declines when a minimum production rate is reached. Truncating a hyperbolic decline with an exponential decline solves some of the problems associated with decline curve analysis, but it is not an ideal solution. The exponential decline rate used is arbitrary, and the value picked greatly effects the results of the forecast. A new empirical model has been developed and used as an alternative to traditional decline curve analysis with the Arps equation. The new model is based on the concept of logistic growth models. Logistic growth models were originally developed in the 1830s by Belgian mathematician, Pierre Verhulst, to model population growth. The new logistic model for production forecasting in ultra-tight reservoirs uses the concept of a carrying capacity. The carrying capacity provides the maximum recoverable oil or gas from a single well, and it causes all forecasts produced with this model to be within a reasonable range of known volumetrically available oil. Additionally the carrying capacity causes the production rate forecast to eventually terminate as the cumulative production approaches the carrying capacity. The new model provides a more realistic method for forecasting reserves in unconventional formations than the traditional Arps model. The typical problems encountered when using conventional decline curve analysis are not present when using the logistic model. Predictions of the future are always difficult and often subject to factors such as operating conditions, which can never be predicted. The logistic growth model is well established, robust, and flexible. It provides a method to forecast reserves, which has been shown to accurately trend to existing production data and provide a realistic forecast based on known hydrocarbon volumes.
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46

Chen, Chien-Hung y 陳建宏. "Analyzing Urbanization Data Using Logistic Growth Model: The case of APEC". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/3wx49k.

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碩士
長榮大學
土地管理與開發學系碩士班
104
Level of urbanization is an important indicator to predict a number of global trends, however, level of urbanization may be based on unreliable data. This research proposes an simple method to identify a country's urban and country population time series if there is a problem, and to find the upper limit of level of urbanization tendency to view urbanization whether follows logistic growth model. Empirical analysis of the Asia-Pacific Economic Cooperation member countries’ urban and country population time series were used to verify the reliability of the data. This study will investigate the urbanization of each APEC member countries. As long as the study sample shows S-shaped growth curve, this method will be effective, but the urban population change and urbanization level predicted in this study found that some outliers should exist. An exception occurs because the value of its national saturation value is abnormal, indicating urbanization is relevant to the background and characteristics of the country. Therefore, to use Logistic growth model to explore the urbanization of a country, we should be aware of its applicability and restriction.

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47

Cai, Longyao. "Logistic Growth Models for Estimating Vaccination Effects In Infectious Disease Transmission Experiments". Thesis, 2013. http://hdl.handle.net/10214/5314.

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Veterinarians often perform controlled experiments in which they inoculate animals with infectious diseases. They then monitor the transmission process in infected animals. The aim of such experiments can be to assess vaccine effects. The fitting of individual-level models (ILMs) to the infectious disease data, typically achieved by means of Markov Chain Monte Carlo (MCMC) methods, can be computationally burdensome. Here, we want to see if a vaccination effect can be identified using simpler regression-type models rather than the complex infectious disease models. We examine the use of various logistic growth curve models, via a series of simulated experiments in which the underlying true model is a mechanistic model of infectious disease spread. We want to investigate whether a vaccination effect can be identified when only partial epidemic curves are observed, and to assess the performance of these models when experiments are run with various sets of observational times.

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48

"Qualitative analysis of a PDE model for chemotaxis with logarithmic sensitivity and logistic growth". Tulane University, 2021.

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archives@tulane.edu
This thesis examines the qualitative behavior of solutions to a PDE model for chemotaxis; that is the existence, uniqueness and asymptotic behavior of solutions. We study initial-boundary value problems for a chemotaxis model with logarithmic sensitivity and logistic growth for the cell population density, and nonlinear growth of the chemical concentration. Extensive work has been done for this particular model without logistic growth on both bounded and unbounded domains. However, the model with logistic growth on a bounded domain has not been studied before. This case is of particular interest given its relevance for modeling tumor angiogenesis. We first establish global well-posedness of strong solutions for large initial data with no-flux boundary conditions and, moreover, establish the qualitative result that both the population density and chemical concentration asymptotically converge to constant states. The population density in particular converges to its carrying capacity. We additionally prove that the vanishing chemical diffusivity limit holds in this regime. Finally, we provide numerical confirmation of the rigorous qualitative results, as well as numerical simulations that demonstrate a separation of scales phenomenon. We then establish global well-posedness of strong solutions for large initial data with dynamic boundary conditions. Moreover, the solutions will asymptotically approach the boundary data under mild and natural assumptions on the boundary functions. We additionally show the formation of a boundary profile in the singular chemical zero diffusive limit. Lastly, we provide numerical simulations that confirm the boundary layer formation, as well as convergence towards certain steady states of the solution when relaxing the assumptions on the boundary data. The main tool developed in these results is a particular Lyapunov functional that helps overcome the mathematical challenges of the non-conservation of the mass due to the logistic growth. These results give a complete study of this particular system on bounded domains with both zero-flux and dynamic moving boundary conditions.
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Padi Fuster Aguilera

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Juan, Hui-Wen y 阮慧雯. "Discussion on Value Innovation for Enterprise Sustainable Growth ~X logistic company as the research object". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/kg78g4.

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Resumen

碩士
國立臺灣科技大學
管理研究所
107
In the face of today’s rapid technology advancement and fierce competition, Kodak, Nokia, had once dominated its field, failed to kick-off its transformation in a timely manner, resulting in its struggle to stay alive. In contrast, some companies have long awakened to the realization that they cannot depend on present profits to bolster their future sustainability. For instance, Corning, Netflix and other companies know how to consider "the second curve" in business and how to find solutions for their balanced development through "value innovation". Value innovation is a compulsory course for companies to make great strides towards reaching sustainable growth. It requires a combination of strategy, organizational change, talent and corporate culture. Value innovation is a project that must be constantly carried out. "Think Big, Start Small" is how to react to the increasingly complex industrial supply chain relationship and the trend of more customers' demands for integrated services. When thinking about the future development of companies, management scope must start from the top with a holistic perspective to view the strategic layout of the entire "business ecosystem". At the time of implementation, the transformation should be carried out at the most fundamental level. Moving from implementation to transformation, is a road full of obstacles and uncertainties; however, only by taking this step can companies gain a foothold on the international stage in the future.

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50

Lee, Chih-Yuan y 李致遠. "The Two-Species Logistic Growth-Transition model and the Discussion of Its Biological Application: A Mathematical Model of Heterogeneous Cancer Growth with Autocrine Signaling Pathway". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/12560479017310280317.

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碩士
國立臺灣大學
物理研究所
100
In this thesis, I and my senior colleague, Dr. Geng-Ming Hu, develop a biological mathematical model in which the mathematical essence is derived from the paper “Transcriptome-wide noise controls lineage choice in mammalian progenitor cells”. At first, we want to find out some interesting mathematical characteristics such as limiting cycle, but we find that it’s almost impossible to do so. Then when we research associated biological model, we find that our model may have better biological and mathematical interpretation than other models and that our model could fit well with cancer stem cell hypothesis and associated experimental data. Thus we develop our own model with its new biological essence and use it to make excellent fit with associated experimental data. Part of our research is being published in Cell Proliferations under the title “A Mathematical Model of Heterogeneous Cancer Growth with Autocrine Signaling Pathway.”

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Tesis sobre el tema "Logistic growth"

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