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Kubo, Fukuichiro. "Investigation of modified Weingarten model." 京都大学 (Kyoto University), 2007. http://hdl.handle.net/2433/136757.
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Martorello, Cristiane Dias de Souza. "Epidemiology in complex networks - modified heterogeneous mean-field model." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/100/100132/tde-16012019-173906/.
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The study of complex networks presented a huge development in last decades. In this dissertation we want to analyze the epidemic spread in scale-free networks through the Susceptible - Infected - Susceptible (SIS) model. We review the fundamental concepts to describe complex networks and the classical epidemiological models. We implement an algorithm that produces a scale-free network and explore the Quenched Mean-Field (QMF) dynamics in a scale-free network. Moreover, we simulate a change on the topology of the network according to the states of the nodes, and it generates a positive epidemic threshold. We show analytically that the fraction of infected vertices follows a power-law distribution in the vicinity of this critical point<br>O estudo de redes complexas tem se desenvolvido muito nos últimos anos. Nesta dissertação queremos analisar o processo de propagação de epidemia em redes livres de escala através do modelo Suscetível - Infectado - Suscetível (SIS). Apresentamos uma revisão de redes e as principais características dos modelos epidemiológicos clássicos. Implementamos um algoritmo que produz uma rede livre de escala dado um expoente e exploramos a dinâmica do modelo Quenched Mean-Field (QMF) inserido em uma rede livre de escala. Além disso, foi simulada uma possível alteração na topologia da rede, devido aos estados dos vértices infectados, que gerou um limiar epidêmico positivo no modelo e a probabilidade de vértices infectados seguiu uma lei de potência na vizinhança desse ponto crítico
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Schønberg, Vegard, and Christian Dalheim Øien. "Simulations of impact using the modified Gurson model." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for bygg, anlegg og transport, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18779.
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We have performed modified Gurson model calibrations to the steel alloys Weldox 460E, Weldox 700E and Weldox 900E through finite element method (FEM) simulations of various tensile material tests performed, and used these material models to perform FEM simulations of impact of blunt tool steel projectiles on target plates made out of these steel alloys. The purpose of these FEM simulations was to study the dependence of target plate steel alloy on the ballistic limit velocity of the projectile resulting from the modified Gurson model. It was found that the modified Gurson model is able to reproduce the dependence seen in experiments, but that it is strongly dependent on a certain model parameter related to the shear stress dependence on material damage. We have also discovered potential problems, and possible solutions, regarding the calibration of these material models and the use of them in the FEM impact simulations carried out.
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Brock, Jerry S. "A modified Baldwin-Lomax turbulence model for turbomachinery wakes." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-09052009-040231/.
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Albarracin, Orlando Yesid Esparza. "Generalized autoregressive and moving average models: control charts, multicollinearity, and a new modified model." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/45/45133/tde-21112017-184544/.
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Recently, in the health surveillance area, control charts have been proposed to decide if the morbidity or mortality of a specific disease reached an epidemic level. This thesis is composed by 3 papers. In the first two papers, CUSUM and EWMA control charts were proposed to monitor count time series with seasonal and trend effects using the Generalized Autoregressive and Moving Average models (GARMA), instead of the independent Generalized Linear Model (GLM) as it is usually used in practice. Different statistics based on transformations, for variables that follow a Negative Binomial distribution, were used in these control charts. In the second paper, two new statistics were proposed based on the ratio of log-likelihood function. Different scenarios describing disease profiles were considered to evaluate the effect of omission of serial correlation in EWMA and CUSUM control charts. The performance of CUSUM and EWMA charts when the serial correlation is neglected in the regression model was measure in terms of average run length (ARL). In summary, when the autocorrelation is neglected, fitting a pure GLM instead of a GARMA model will lead to an increase of false alarms. However, no statistics among the tested ones seem to be robust, in a sense to produce the smallest increase of false alarms in all scenarios. In general, all monitored statistics presented a smaller ARL_0 for higher values of autocorrelation. \\\\ In the last paper, the GARMA models (p, q) with p and q simultaneously different from zero were studied since that two features were observed in practice. One is the multicollinearity, which may lead to a non-convergence of the maximum likelihood, using iteratively reweighted least squares. The second is the inclusion of the same lagged observations into the autoregressive and moving average components confounding the interpretation of the parameters. In a general sense, simulation studies show that the modified model provide estimators closer to the parameters and offer confidence intervals with higher coverage percentage than obtained with the GARMA model, but some restrictions in the parametric space are imposed to guarantee the stationarity of the process. Also, a real data analysis illustrate the GARMA-M fit for daily hospilatization rates of elderly people due to respiratory diseases from October 2012 to April 2015 in São Paulo city, Brazil.<br>Recentemente, no campo da saúde, gráficos de controle têm sido propostos para monitorar a morbidade ou a mortalidade decorrentes de doenças. Este trabalho está composto por três artigos. Nos dois primeiros artigos, gráficos de controle CUSUM e EWMA foram propostos para monitorar séries temporais de contagens com efeitos sazonais e de tendência usando os modelos Generalized autoregressive and moving average models (GARMA), em vez dos modelos lineares generalizados (GLM), como usualmente são utilizados na prática. Diferentes estatísticas baseadas em transformações, para variávies que seguem uma distribuição Binomial Negativa, foram usadas nestes gráficos de controle. No segundo artigo foram propostas duas novas estatísticas baseadas na razão da função de log-verossimilhança. Diferentes cenários que descrevem perfis de doenças foram considerados para avaliar o efeito da omissão da correlação serial nesses gráficos de controle. Este impacto foi medido em termos do Average Run Lenght (ARL). Notou-se que a negligência da correlação serial induz um aumento de falsos alarmes. Em geral, todas as estatísticas monitoradas apresentaram menores valores de ARL_0 para maiores valores de autocorrelação. No entanto, nenhuma estatística entre as consideradas mostrou ser mais robusta, no sentido de produzir o menor aumento de falsos alarmes nos cenários considerados. No último artigo, foram estudados os modelos GARMA (p, q) com p e q simultaneamente diferentes de zero, uma vez que duas características foram observadas na prática. A primeira é a presença de multicolinearidade, que induz à não-convergência do método de máxima verossimilhança usando mínimos quadrados ponderados reiterados. A segunda é a inclusão dos mesmos termos defasados nos componentes autorregressivos e de médias móveis. Um modelo modificado, GARMA-M, foi apresentado para lidar com a multicolinearidade e melhorar a interpretação dos parâmetros. Em sentido geral, estudos de simulação mostraram que o modelo modificado fornece estimativas mais próximas dos parâmetros e intervalos de confiança com uma cobertura percentual maior do que a obtida nos modelos GARMA. No entanto, algumas restrições no espaço paramétrico são impostas para garantir a estacionariedade do processo. Por último, uma análise de dados reais ilustra o ajuste do modelo GARMA-M para o número de internações diárias de idosos devido a doenças respiratórias de outubro de 2012 a abril de 2015 na cidade de São Paulo, Brasil.
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Nyström, Anton. "Gesture-level model : A modified Keystroke-level model for tasks on mobile touchscreen devices." Thesis, Uppsala universitet, Institutionen för informatik och media, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-356435.
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The aim of this thesis was to develop a touchscreen-adapted version of the well established Keystroke-level model, which is a user performance model designed to be a quick and easy way to evaluate user interfaces prior to creating prototypes. A quantitative research method was chosen to measure general execution times for common touchscreen gestures on mobile devices. Over 1000 data points were collected from participants who partook in a observational experiment using a prototype specifically programmed for this study. The results of the thesis involves the analyzed measurements acquired from the experiment, as well as a four important aspect to consider when performing similar experiments, namely: (1) The individual speed of the participants; (2) The participants’ level of expertise; (3) The participants’ methods of performing the gestures; (4) Designing the experiment for medium difficulty.<br>Målet med denna uppsats var att utveckla en pekskärmsanpassad version av den välkända modellen Keystroke-level model, vilket är en modell som kan användas för att snabbt och enkelt utvärdera gränssnitt utan att behöva utveckla fungerande prototyper. En kvantitativ forskningsmetod användes för att mäta hur lång tid det tar för användare generellt att utföra de vanligaste fingergesterna på mobila pekskärmar. Över 1000 datapunkter samlades in från ett experiment där deltagarna fick använda en prototyp som automatiskt mätte den tid det tog för användarna att utföra de olika fingergesterna. Resultaten av studien består av de mätvärden som räknats ut samt fyra aspekter som är viktiga att ha i beaktning när liknande experiment ska utformas. Dessa är: (1) Varje deltagares individuella hastighet; (2) Deltagarnas pekskärmsvana; (3) Sättet de olika deltagarna utför fingergesterna; (4) Utforma experimentet för att representera en medium svårighetsgrad.<br>Le but de ce projet fut de créer une version du Keystroke-level model adaptée aux écrans tactiles. Ce modèle de performance utilisateur est une méthode d’évaluation simple et rapide d’interfaces utilisateur avant la création de prototypes. Une étude quantitative fut choisie pour mesurer le temps d’exécution général de mouvements spécifiques effectués sur des écrans tactiles de téléphones. Plus de 1000 points de données furent collectés auprès de participants ayant pris part à une étude observationnelle utilisant un prototype spécialement programmé pour l’occasion. Les résultats de ce projet incluent l’analyse des mesures acquises lors de cette étude ainsi que quatre aspects importants à considérer lors de la réalisation d’études similaires, à savoir: (1) La vitesse individuelle des participants; (2) Le niveau d’habitude d’utilisation d’écrans tactiles des participants; (3) Les méthodes utilisées par les participants lors de la réalisation des mouvements; (4) La conception d’étude pour des mouvements de difficulté dite moyenne.
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Zhou, Maichun, and 周買春. "Modified Xinanjiang model and its incorporation with GIS and topmodel." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31241402.
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Mellor, Dale. "The modified turning bands (MTB) model for space-time rainfall." Thesis, University of Newcastle Upon Tyne, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357808.
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Xie, Xiaoyue S. B. Massachusetts Institute of Technology. "Modified Maxwell Model for hysteresis compensation of piezoelectric stack actuators." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98747.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (page 29).<br>This thesis presents new observations of the hysteresis behavior of piezoelectric stack actuators and proposes an Input-Range Dependent Maxwell Model for more accurate hysteresis compensation. Experimental studies show that the assumptions of the classical Maxwell model do not fully hold: the actuator behaves differently in the initiation stage compared to the later cycles, and the parameters of the Maxwell model are dependent on the input history. Two most prominent factors are the input range of the most recent half loop and the local extremum input at the beginning of the current half loop. To accommodate for these variations, two types of modified Maxwell model are presented: the Input-Range Dependent Maxwell Model and the Local-Extremum Dependent Maxwell Model. We further propose parameter estimation schemes for each modified model. In both models, one set of parameters is obtained for the initiation stage and another set for later cycles, and the first Maxwell spring constant is related to the input history - input range or local extremum, respectively. Further studies suggested that the linear dependence of the first spring constant on the input range is much stronger than on the local extremum. Simulations with the identified Input-Range Dependent Maxwell Model gave a maximum percentage error of 2.71%, as compared with a percentage error of 8.29% using the classical Maxwell model. This suggests that the model can accurately predict the response of a piezoelectric stack actuator and is promising for hysteresis compensation in nano-positioning applications.<br>by Xiaoyue Xie.<br>S.B.
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Martins, João Pedro Lourenço. "Characterization by model reactions of modified EUO and MWW zeolites." Thesis, Poitiers, 2012. http://www.theses.fr/2012POIT2282/document.
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L'EU-1 et la MCM-22 sont deux zéolithes à taille de pores intermédiaire, utilisées respectivement pour l'isomérisation de la coupe C8 aromatique et l'alkylation du benzène par des oléfines légères. Leurs propriétés catalytiques originales sont dues à une contribution très importante des sites acides localisés sur leur surface externe. Au cours de ce travail, différentes approches ont été envisagées pour augmenter la quantité ou la proportion de ces sites aux dépends des sites internes. Tout d'abord, une série de zéolithes H-EU-1 partiellement échangées par du sodium a été préparée et caractérisée par voie physicochimique et par des réactions modèles. Comme attendu, l'échange s'accompagne d'une diminution de la concentration en sites acides de Brönsted. Toutefois, une augmentation importante de la quantité de sites acides très forts a été observée pour des taux d'échange de 26 à 35 % et corrélée à l'augmentation de l'activité en craquage du méthylcyclohexane. Par ailleurs, les conversions du m-xylène et du 1,3,5-triméthylbenzène diminuent rapidement pour de faibles taux d'échange, ce qui pourrait s'expliquer par un échange préférentiel des sites acides externes, également mis en évidence dans le cas de zéolithes MCM-22. Enfin, une nouvelle zéolithe de la famille MWW a été synthétisée et caractérisée. Cette zéolithe possède une acidité totale similaire à celle de la MCM-22, mais une proportion de sites acides externes beaucoup plus importante, conduisant à une activité beaucoup plus grande en transformation du m-xylène et du 1,3,5-triméthylbenzène. Cette nouvelle zéolithe pourrait donc constituer une alternative intéressante à la zéolithe MCM-22 en alkylation du benzène<br>EU-1 and MCM-22 are two 10-ring zeolites used in petrochemical applications such as C8-aromatic cut isomerization and benzene alkylation with short olefins. In all these processes, the original catalytic behaviors of both zeolites are characterized by an important contribution of the acid sites located over the external surface of their crystals. In this work, different methods were investigated in order to increase the amount or the proportion of these acid sites at the expense of those located inside the pores. Firstly, a series of partially Na-exchanged H-EU-1 was prepared and fully characterized through physicochemical techniques and model reactions. As expected, the exchange led to a gradual decrease in the total Brönsted site concentration. Nevertheless, an increase of the concentration in very strong acid sites was obtained for exchange ratio between 26 and 35%, leading to a significant increase of the activity in methylcyclohexane transformation. On the other hand, m-xylene and 1,3,5-trimethylbenzene (135-TMB) conversions decreased rapidly at low exchange ratio, which was attributed to a preferential exchange of the external acid sites. This latter phenomenon was also observed over Na-exchanged H-MCM-22 zeolites. Secondly, a new zeolite belonging to the MWW family was synthesized and characterized. This zeolite was shown to possess the same acid site concentration than MCM-22 zeolite but with a much higher proportion of external sites. In consequence, it exhibited a very high catalytic activity in both m-xylene and 135-TMB transformations. This material could therefore be considered as an alternative to MCM-22 in the benzene alkylation process<br>EU-1 e MCM-22 são dois zeólitos de poros intermédios utilizados, respetivamente, na isomerização do corte C8 aromático e na alquilação do benzeno com olefinas leves. As suas propriedades catalíticas originais devem-se a uma importante contribuição dos centros ácidos localizados nas superfície externa. Nesta tese, diferentes abordagens foram investigadas com o objetivo de aumentar a quantidade ou a proporção destes centros ácidos em detrimento dos centros internos. Primeiramente, uma série de zeólitos H-EU-1 parcialmente permutados com sódio foi preparada e caracterizada por via físico-química e por reações modelo. Como esperado, a permuta é acompanhada por uma diminuição da concentração em centros ácidos de Brönsted. Contudo, um importante aumento da quantidade de centros ácidos muito fortes foi obtido para taxas de permuta entre 26 e 35% e correlacionado com um aumento da atividade no cracking do metilciclohexano. Por outro lado, as conversões do m-xileno e do 1,3,5-trimetilbenzeno diminuem rapidamente para baixas taxas de permuta, o que pode ser explicado por uma permuta preferencial dos centros ácidos externos. Este último fenómeno foi igualmente observado no caso do zeólito H-MCM-22 permutado com sódio. Por fim, um novo zeólito pertencente à família MWW foi sintetizado e caracterizado. Este zeólito demonstrou possuir uma acidez total semelhante à do zeólito MCM-22, porém com uma muito maior proporção de centros ácidos externos, conduzindo a uma bastante superior atividade nas transformações do m-xileno e do 1,3,5-trimetilbenzeno. Este novozeólito poderá, portanto, representar uma alternativa interessante ao zeólito MCM-22 na alquilação do benzeno
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Lee, Youngho. "Finite element model updating of loaded and geometrically modified structures." Thesis, University of Bristol, 2006. http://hdl.handle.net/1983/f7493e73-ad88-438c-8b8e-a3e801ec9947.
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Gassner, Lina. "Developing metacognitive awareness - a modified model of a PBL-tutorial." Thesis, Malmö högskola, Odontologiska fakulteten (OD), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-19779.
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In order for students to become good self-directed learners, an awareness of one’s own learning process and studying strategies is essential. The aim of this paper is to describe a project –and the results of it - where a modified model of a problem-based learning (PBL) tutorial is used, a project launched to develop students’ metacognitive awareness and improve the quality of their tutorials. Dental hygiene students and their tutors at the faculty of Odontology, Malmö University participated in the project which meant that the students worked independently during the first PBL-session with the tutor only paying a few short visits to the group. At these visits, the students presented their problems, hypotheses and objectives with the purpose to create an opportunity of primarily reviewing and reflecting but also getting feed-back from the tutor. The tutor was present throughout the second PBL-session. This model was alternated with and compared to the traditional “Malmö model” in which the tutor participates throughout both PBL-sessions. The project was evaluated through interviews. A Metacognitive Awareness Inventory (MAI) was filled in before and after the project. Results for the MAI show a significant increase in metacognitive awareness. In the interviews, students state that they participated in the PBL-session to a greater extent and had more spontaneous discussions without the tutor, but also that they felt a lack of security and sometimes interrupted by the visits from the tutor.
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Mead, Alexander James. "Demographics of dark-matter haloes in standard and non-standard cosmologies." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/9951.
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This thesis explores topics related to the formation and development of the large-scale structure in the Universe, with the focus being to compute properties of the evolved non-linear density field in an approximate way. The first three chapters form an introduction: Chapter 1 contains the theoretical basis of modern cosmology, Chapter 2 discusses the role of N-body simulations in the study of structure formation and Chapter 3 considers the phenomenological halo model. In Chapter 4 a novel method of computing the matter power spectrum is developed. This method uses the halo model directly to make accurate predictions for the matter spectrum. This is achieved by fitting parameters of the model to spectra from accurate simulations. The final predictions are good to 5% up to k = 10 hMpc-1 across a range of cosmological models at z = 0, however accuracy degrades at higher redshift and at quasi-linear scales. Chapter 5 is dedicated to a new method of rescaling a halo catalogue that has previously been generated from a simulation of a specific cosmological model to a different model; a gross rescaling of the simulation box size and redshift label takes place, then individual halo positions are modified in accord with the large scale displacement field and their internal structure is altered. The final power spectrum of haloes can be matched at the 5% level up to k = 1 hMpc-1, as can the spectrum of particles within haloes reconstituted directly from the rescaled catalogues. Chapter 6 applies the methods of the previous two chapters to modified gravity models. This is done in as general a way possible but tests are restricted to f(R) type models, which have a scale-dependent linear growth rate as well as having 'chameleon screening' - by which modifications to gravity are screened within some haloes. Taking these effects into account leads to predictions of the matter spectrum at the 5% level and rescaled halo distributions that are accurate to 5% in both real and redshift space. For the spectrum of halo particles it is demonstrated that accurate results may be obtained by taking the enhanced gravity in some haloes into account.
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Izgec, Bulent. "Performance analysis of compositional and modified black-oil models for rich gas condensate reservoirs with vertical and horizontal wells." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/237.
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It has been known that volatile oil and gas condensate reservoirs cannot be modeled accurately with conventional black-oil models. One variation to the black-oil approach is the modified black-oil (MBO) model that allows the use of a simple, and less expensive computational algorithm than a fully compositional model that can result in significant timesaving in full field studies. The MBO model was tested against the fully compositional model and performances of both models were compared using various production and injection scenarios for a rich gas condensate reservoir. The software used to perform the compositional and MBO runs were Eclipse 300 and Eclipse 100 versions 2002A. The effects of black-oil PVT table generation methods, uniform composition and compositional gradient with depth, initialization methods, location of the completions, production and injection rates, kv/kh ratios on the performance of the MBO model were investigated. Vertical wells and horizontal wells with different drain hole lengths were used. Contrary to the common belief that oil-gas ratio versus depth initialization gives better representation of original fluids in place, initializations with saturation pressure versus depth gave closer original fluids in place considering the true initial fluids in place are given by the fully compositional model initialized with compositional gradient. Compared to the compositional model, results showed that initially there was a discrepancy in saturation pressures with depth in the MBO model whether it was initialized with solution gas-oil ratio (GOR) and oil-gas ratio (OGR) or dew point pressure versus depth tables. In the MBO model this discrepancy resulted in earlier condensation and lower oil production rates than compositional model at the beginning of the simulation. Unrealistic vaporization in the MBO model was encountered in both natural depletion and cycling cases. Oil saturation profiles illustrated the differences in condensate saturation distribution for the near wellbore area and the entire reservoir even though the production performance of the models was in good agreement. The MBO model representation of compositional phenomena for a gas condensate reservoir proved to be successful in the following cases: full pressure maintenance, reduced vertical communication, vertical well with upper completions, and producer set as a horizontal well.
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Raychoudhury, Trishikhi. "Transport of surface-modified iron nanoparticles through model subsurface porous media." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104765.
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AbstractThe overall objective of this research is to evaluate significant mechanisms for deposition of surface-modified NZVI in granular subsurface media during transport. Although surface-modified NZVI have been shown to transport more easily than bare NZVI, there is a lack of knowledge of how different parameters such NZVI particle concentration, NZVI size, aqueous-phase flow velocity, and sand particle size influence nanoparticle transport. To investigate the effects of these parameters on transport, a number of laboratory experiments were conducted with NZVI synthesized from ferrous sulfate in the presence of polymers that were effective in colloidal stabilization of the particles. The bare and surface modified-NZVI was characterized for size and surface chemistry by a wide array of analytical instruments. The polymer-stabilized NZVI were employed in three different studies to identify parameters that influence deposition of NZVI in model, granular, subsurface media. In the first study, the breakthrough patterns of carboxymethyl cellulose (CMC)- and polyacrylic acid (PAA)- stabilized NZVI eluted from packed sand columns under a range of pore water velocities and NZVI influent concentrations were investigated. The NZVI effluent relative concentrations of both types of particles decreased with decreasing flow velocities and increasing particle concentrations. PAA-NZVI exhibited slower elution from the columns than CMC-NZVI under identical experimental conditions, and this is attributed to more rapid aggregation kinetics of PAA-NZVI. The second study focused on the quantitative evaluation of aggregation kinetics and the possible effects of aggregation on NZVI deposition. Aggregation of CMC-NZVI particles resulted in a change in particle size distribution (PSD) with time, and the changes in particle size were evaluated by nanoparticle tracking analyzer (NTA). The effects of particle concentrations on the transport in porous media were evaluated by comparing the time profiles of elution of CMC-NZVI from packed sand columns. Changes in PSD over time were responsible for a gradual increase in effluent concentration between 1 and 4 pore volumes, and beyond 4 pore volumes particle detachment contributed to non-steady state effluent concentrations. The NZVI elution profiles had a good fit with aggregation kinetics equations coupled to colloid transport equations that account for particle deposition and detachment. The third study focused on assessing the significance of straining of CMC-NZVI particles during transport in model subsurface porous media. Laboratory experiment were conducted to assess the transport of CMC-NZVI in columns packed with four different sized sands and with three different concentrations. . Breakthrough curves (BTC) and retention profiles of CMC-NZVI along the column length were analyzed to characterize CMC-NZVI transport. The breakthrough curves suggest that with decrease in mean sand diameter, the effluent concentrations decrease. Very high CMC-NZVI particle retention towards the inlet, particularly for the finer sands was observed. These observations are consistent with particle retention in porous media due to straining and/or wedging. Two colloid transport models considering 1) particle deposition by attachment only, and 2) particle retention by straining along with particle deposition by attachment were fitted to the experimental data. Comparison of experimental data and the model calculations suggest that in addition to deposition on collector surface, CMC-NZVI particles are removed from the solution by straining in packed sand beds, with straining rate coefficients that decrease with increase in sand diameter.<br>L'objectif global de cette recherche est d'évaluer les mécanismes importants de déposition des particules NZVI modifiées en surface dans les milieux granulaires subsurfaciques pendant le transport. Bien que les particules NZVI modifiées en surface aient montré un transport plus facile que les particules NZVI nues, il y a un manque de connaissance sur la façon dont des simples paramètres, tel que la concentration des particules NZVI, leur taille, la vitesse d'écoulement de la phase aqueuse et la taille des particules de sable, influencent le transport des nanoparticules. Dans la première étude, on a étudié les modèles des particules CMC- et PAA-ZVI élues des colonnes remplies de sable dans une gamme de vitesses de l'eau des pores, et des concentrations influentes de particules NZVI. . Les concentrations effluentes relatives des deux types de particules NZVI ont diminué avec la diminution des vitesses d'écoulement et avec l'augmentation des concentrations des particules. Les particules PAA-NZVI présentaient une élution plus lente que les particules CMC-NZVI dans des conditions expérimentales identiques, ceci étant attribué à une cinétique d'agrégation plus rapide pour les particules PAA-NZVI. La réduction de la stabilité colloïdale due à l'agrégation des particules CMC- et PAA-NZVI a été vérifiée en utilisant les tests de sédimentation et on a trouvé que les particules PAA-NZVI ont été moins stables que les particules CMC-NZVI. La deuxième étude portait sur l'évaluation quantitative de la cinétique d'agrégation et les effets d'agrégation possibles sur la déposition des particules NZVI. L'agrégation des particules CMC-NZVI a entraîné un changement dans la distribution de la taille des particules (PSD) avec le temps, et les changements dans la taille des particules étaient évalués par l'analyse de suivi des nanoparticules (NTA). Les effets de la concentration des particules dans la gamme sur le transport dans les milieux poreux ont été évalués en comparant les profils de temps d'élution des particules CMC-NZVI dans les colonnes remplies de sable. Les profils d'élution des particules NZVI ont eu un bon ajustement avec les équations cinétiques d'agrégation couplées aux équations de transport colloïdal, qui tiennent compte de la déposition des particules et de détachement. La troisième étude portait sur l'évaluation de l'importance de la filtration des particules CMC-NZVI pendant le transport dans les milieux poreux subsurfaciques modèles. Des expériences de laboratoire ont été effectuées pour évaluer le transport des particules CMC-NZVI dans les colonnes et trois concentrations différentes. Les courbes percées (BTC) et les profils de rétention des particules CMC-NZVI le long de la colonne ont été analysés afin de caractériser le transport. Les courbes BTC suggèrent que les concentrations effluentes diminuent avec la diminution du diamètre moyen du sable. Une très élevée rétention des particules CMC-NZVI a été observée, particulièrement pour les sables plus fins. Ces observations sont en accord avec la rétention des particules dans les milieux poreux due à la filtration et au calage. Deux modèles de transport colloïdal qui considèrent 1) la déposition des particules uniquement par attachement, et 2) la rétention des particules par filtration et déposition par attachement, ont été ajustés aux données expérimentales. La comparaison des données expérimentales avec les calculs du modèle suggèrent qu'en plus de la déposition sur la surface du collecteur, les particules CMC-NZVI sont retirées de la solution par filtration dans les lits remplis de sable, avec des coefficients de filtration qui diminuent avec le diamètre du sable.
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Shahinian, Sarkis Serge. "Biophysical and functional properties of lipid-modified proteins and model lipopeptides." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40439.
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Three related studies were carried out to understand better the physical properties, cellular function, and means to prepare artificially proteins 'anchored' to membranes by two hydrophobic chains.<br>The first study entailed the development of efficient methodologies to conjugate antibody Fab$ sp prime$ fragments to suitable lipid 'anchors' in liposomes, to allow for the targeted delivery of liposome-associated materials to cells expressing the appropriate cell surface determinant. To monitor the production of Fab$ sp prime$ fragments bearing reactive thiol groups, we developed a maleimide-polyethylene glycol (PEG) conjugate 'thiol reagent' for use in an SDS-PAGE mobility shift assay. Optimizing conditions for Fab$ sp prime$ preparation developed by this approach, we achieved efficient and reproducible coupling of Fab$ sp prime$ fragments to liposomes via a novel lipid 'anchor'. Such Fab$ sp prime$-'targeted' liposomes efficiently delivered encapsulated materials to cultured cells in vitro.<br>The second study used lipid-modified peptides to investigate the strength of membrane anchoring conferred by dual lipid modifications of the types attached to various intracellular proteins. Based on kinetic measurements of interbilayer transfer of such peptides and peptide-macromolecule conjugates, we suggest that doubly-modified proteins exhibit extremely slow rates of spontaneous intermembrane transfer. We have proposed mechanisms by which this property of 'dual-anchored' proteins may be exploited to achieve efficient subcellular targeting by 'trapping' mechanisms.<br>The third study sought to assess current models of the mechanism of preferential localization of glycosylphosphatidylinositol (GPI)-proteins to specialized plasma membrane invaginations known as caveolae. This was accomplished using cell membrane-incorporated lipid-PEG-biotin-streptavidin conjugates, whose lateral distribution under various conditions ($ pm$ crosslinking) shows significant overlap with that of endogenous GPI-proteins. We propose a novel mechanistic model based on 'surface-crowding' effects, for the preferential association of lipid-anchored molecules with caveolae, particularly upon crosslinking.
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Petersen, Stefan. "Aspects of solitons in noncommutative field theories the modified Ward model /." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=983545502.
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Beamguard, Miles B. "Mathematical model of arsenic adsorption in a modified zeolite / Microfiltration System." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001804.
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Zhu, Jiqing. "Towards a Viscoelastic Model for Phase Separation in Polymer Modified Bitumen." Licentiate thesis, KTH, Bro- och stålbyggnad, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-163540.
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In this thesis, a review is given on the most popular polymers used today for polymer modification of bitumen. Furthermore, the development of a model for phase separation in polymer modified bitumen (PMB) is proposed, that will enable a better control and understanding of PMB phase behaviour, allowing thus to enhanced long-term performance. PMB is hereby considered as a blend and focus is placed on its structure, its equilibrium thermodynamics and its phase separation dynamics. The effects of dynamic asymmetry on phase separation in PMB are analysed with related theories and some image data. Based on the discussion in this thesis, it is concluded that the effects of dynamic asymmetry between bitumen and polymer should be taken into consideration when studying phase separation in PMB. By analysing related literature and image data, it is found that some features of viscoelastic phase separation are shown during the phase separation process in some PMBs. It is therefore possible and useful to develop a viscoelastic model for PMB to describe its phase separation behaviour. In this, the stress-diffusion coupling is expected to play a key role in the model. Finally, recommendations are made towards the future research which is needed to realize the proposed model.<br><p>QC 20150409</p>
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Brown, Brady A. "Aerosol optical depth retrieval by NPS model modified for SeaWiFS input." Thesis, Monterey, California. Naval Postgraduate School, 2002. http://hdl.handle.net/10945/6091.
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Approved for public release, distribution is unlimited<br>Using visible wavelength radiance data obtained from the spaceborne Sea-viewing Wide Field-of-view Sensor (SeaWiFS), during the Aerosol Characterization Experiment-Asia (ACE-Asia), an analysis of aerosol optical depth (AOD) was completed by modification to the NPS AOD Model previously compiled for NOAA geosynchronous- and polar-orbiting satellites. The objective of the analysis was to calibrate the linearized, single-scatter algorithm, estimated bi-directional surface reflectance, and phase function parameters. The intent of the study was to provide enhanced temporal AOD coverage with the addition of the orbiting SeaWiFS eight-channel radiometer to the established NOAA constellation of five-channel AVHRR-equipped satellites. The work has operational significance in providing timely, accurate remote information to military operators of identification and targeting systems. Possible applications include detection and warning of international treaty violation or reducing the adverse public health effects by weapons of mass destruction or pollution advection on global weather patterns.
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Zhu, Ting. "Color-Based Fingertip Tracking Using Modified Dynamic Model Particle Filtering Method." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306863054.
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Cox-Jones, Gena L. "Job Characteristics Model: Test of a Modified Four-Trait Model at the University of Central Florida." Master's thesis, University of Central Florida, 1987. http://digital.library.ucf.edu/cdm/ref/collection/RTD/id/17301.
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University of Central Florida College of Arts and Sciences Thesis<br>The study examined the nubmer of significant factors in the Hackman and Oldham (1980) job characteristics model. The original factors were: Skill Variety, Task Significance, Task Identity, Autonomy, and Feedback. Scores on these dimensions for 84 employees of the University of Central Florida (21 supervisory and 63 non-supervisory subjects) were used as the basis for this study through a mail administration of the Hackman and Oldham Job Diagnostic Survey (JDS) and their Job Rating Form (JRF). It was hypothesized that: (a) only four significant job dimensions would emerge from factor analysis of the data; (b) that the motiviating potential ratings from job incumbents would be significantly different from those provided by supervisors; and (c) that these motiviating potential scores would be significantly lower than the norm for the job families into which those positions fell. the data failed to lend support to any of the preceeding hypotheses. First, only one significant factor (Skill Variety) was extracted from the non-supervisory data while two factors (Skill Variety and Task Identity) were extracted from the supervisory data. Second, incumbents' ratings were not significantly different from those of their supervisors and third, the motivating potential scores of incumbents were found to be higher than the norm for most of hte job families sampled in the study.<br>M.S.;<br>Arts and Sciences;<br>Industrial/Organizational Psychology<br>89 p.<br>viii, 89 leaves, bound : ill. ; 28 cm.
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Arvelo, Jose. "ADAPTING THE MODIFIED CAM CLAY CONSTITUTIVE MODEL TO THE COMPUTATIONAL ANALYSIS OF DENSE GRANULAR SOILS." Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2452.
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The computational constitutive Modified Cam Clay Model (MCCM) was developed at Cambridge to study the behavior of clays and has been proven to be effective. In this study, this model is extended to the case of dense sands to analyze the accuracy of the stress-strain behavior. This analysis is based on triaxial test data applied to remolded and compacted sand samples under drained conditions. The laboratory triaxial tests were performed by the Florida Department of Transportation to research the permeability effect in sandy soils compacted up to 95% of maximum unit weight at the optimum moisture content. Each soil sample was tested using different stress paths. In addition, these data were also used to obtain the soil parameters. These soil parameters are used as input data for the Modified Cam Clay Model. Moreover, a computer program in MATLAB was developed based on the MCCM constitutive theory and application in order to predict the stress-strain response for overconsolidated soils under drained condition. Based on observations of the qualitative behavior of these soils, a modification is proposed in this thesis to the original constitutive model to improve the predicted stress-strain behavior. The results of the computer program are typically presented in the deviatoric stress versus shear strain and the stress path plane (deviatoric stress versus mean effective stress). These are the principal plots used for the behavior prediction of soil specimens. Furthermore, the results of the computer program were compared to the laboratory triaxial test data. In general, it is may be concluded that, MCCM with some modification, is applicable to dense sands.<br>M.S.C.E.<br>Department of Civil and Environmental Engineering<br>Engineering and Computer Science<br>Civil Engineering
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Schroeder, Hans R. "S-acylation and intracellular targeting of lipid-modified proteins and model lipopeptides." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36812.
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Three related studies were performed to better characterize the intracellular process of protein S-acylation in mammalian cells. The first study focused on the use of cysteinyl-containing fluorescent lipopeptides which mimic the N-terminal of various S-acylable intracellular regulatory proteins. These lipopeptides diffuse rapidly between membranes and are efficiently S-acylated by a variety of mammalian cells. S-acylation appears to be enzymatic by various criteria and is highly selective for cysteinyl as opposed to serinyl residues. Fluorescence microscopy revealed that the plasma membrane is the predominant site for intracellular S-acylation but that a second potential site localized to the Golgi apparatus may also exist.<br>The second study examined the intracellular S-acylation of lipopeptides which mimic the carboxy-terminus of N-ras. S-acylation of lipopeptides was again specific for cysteinyl residues as opposed to serinyl residues. The exact structure of the attached prenyl group, for example the farnesyl versus geranyl group, does not affect the ability of the lipopeptide to undergo S-acylation, however, an attached moiety with sufficient hydrophobicity to promote high affinity but rapidly reversible interactions with membranes is required for efficient S-acylation. Fluorescence microscopy suggests that S-acylation of these peptides and likely N-ras protein itself occurs at the plasma membrane of mammalian cells.<br>The third study examined the hypothesis that proteins of different sequences may be S-acylated by distinct S-acyltransferases. Lipopeptides bearing sequences mimicking the N-termini of src-like nonreceptor protein tyrosine kinases or heterotrimeric G-protein alpha-subunits, incorporate similar ratios of [3H]palmitate/[3H]stearate following incubation of lipopeptide with cells and equal activities of [3H]palmitate and [3H]stearate. In contrast, lipopeptides which mimic the C-terminus of N-ras exhibit ratios which are significantly different from the ratios for those lipopeptides described above. These results suggest that these two groups of structurally-different lipopeptides are S-acylated by distinct S-acyltransferases within the plasma membrane. Further, lipopeptides bearing nonphysiological sequences which are preferentially S-acylated in the Golgi, incorporate radiolabeled fatty acids in ratios which are significantly different from those determined for most lipopeptides S-acylated at the plasma membrane, suggesting that distinct S-acyltransferases may exist in the plasma membrane and Golgi apparatus of mammalian cells.
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Mandelbaum, Saul. "A model of cancer immunotherapy via immunoencapsulation of gene-modified tumour cells." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0025/MQ50438.pdf.
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Tiah, Yao Ming. "An analysis of small navy tactics using a modified Hughes' Salvo Model." Thesis, Monterey, Calif. : Naval Postgraduate School, 2007. http://bosun.nps.edu/uhtbin/hyperion.exe/07Mar%5FTiah.pdf.
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Thesis (M.S. in Operations Research)--Naval Postgraduate School, March 2007.<br>Thesis Advisor(s): Wayne P. Hughes. "March 2007." Includes bibliographical references (p. 85-86). Also available in print.
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Jayasuriya, Wadu M. L. "Dynamic analysis of circular plate on elastic foundation using modified Vlasov model." Ohio : Ohio University, 1992. http://www.ohiolink.edu/etd/view.cgi?ohiou1172686917.
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Chakraverti, Sugandha, Sheo Kumar, S. C. Agarwal, and Ashish Kumar Chakraverti. "Modified Cocomo Model For Maintenance cost Estimation of Real Time System Software." IJCSN, 2012. http://hdl.handle.net/10150/219511.
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Software maintenance is an important activity in
software engineering. Over the decades, software
maintenance costs have been continually reported to
account for a large majority of software costs
[Zelkowitz 1979, Boehm 1981, McKee 1984, Boehm
1988, Erlikh 2000]. This fact is not surprising. On the
one hand, software environments and requirements are
constantly changing, which lead to new software
system upgrades to keep pace with the changes. On
the other hand, the economic benefits of software
reuse have encouraged the software industry to reuse
and enhance the existing systems rather than to build
new ones [Boehm 1981, 1999]. Thus, it is crucial for
project managers to estimate and manage the software
maintenance costs effectively.<br>Accurate cost estimation of software projects is
one of the most desired capabilities in software
development Process. Accurate cost estimates not only help
the customer make successful investments but also assist
the software project manager in coming up with appropriate
plans for the project and making reasonable decisions
during the project execution. Although there have been
reports that software maintenance accounts for the
majority of the software total cost, the software estimation
research has focused considerably on new development and
much less on maintenance. Now if we talk about real time
software system(RTSS) development cost estimation and
maintenance cost estimation is not much differ from simple
software but some critical factor are considered for RTSS
development and maintenance like response time of
software for input and processing time to give correct
output. As like simple software maintenance cost estimation
existing models (i.e. Modified COCOMO-II) can be used
but after inclusion of some critical parameters related to
RTSS.
A Hypothetical Expert input and an industry data set of
eighty completed software maintenance projects were used
to build the model for RTSS maintenance cost. The full
model, which was derived through the Bayesian analysis,
yields effort estimates within 30% of the actual 51% of
the time,outperforming the original COCOMO II model
when it was used to estimate theseprojects by 34%.
Further performance improvement was obtained when
calibrating the full model to each individual program,
generating effort estimates within 30% of the actual 80%
of the time.
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Parthasarathy, Meghana. "Analyzing Warehouse-Retailer Interaction using a Modified Economic Order Quantity (EOQ) Model." Ohio University / OhioLINK, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1103228627.
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Eltayeb, Yousif Mazin Fadl Elhag. "Non-linear bond modelling for reinforced concrete : a newly-modified bond model." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608831.
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Ku, Wei-lien, and 古維廉. "Modified Duration Vector under HJM Model." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/48586466571590353019.
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碩士<br>國立臺灣大學<br>財務金融學研究所<br>90<br>Abstract：In the past, the study of interest rate instruments focused on constructing bond portfolios and pricing derivatives. However, when constructing portfolios investors ought to take interest rate derivatives into consideration, because their lower transaction cost, higher interest rate sensitivity.
Immunization is a main subject in managing the portfolio of interest rate instruments. The way to immunization is divided into multi-factor and single-factor. The most famous immunization strategy of the former is to use Macaulay duration. As to that of the later, empirical studies support M vector. But their assumptions are so severe that using these strategies is restricted.
This paper modifies continuous duration vector (Nawalkha,1995) by HJM Model. Under HJM model, the paper derives a more delicate model which can fit term structure and volatility curve. Given main volatility curve including constant, exponential dampen and hump, this paper supplies different formulas.
Although continuous duration vector can’t be used directly, its formula is general under loose assumptions. Using HJM model to modify it in the paper, the price changes of bonds and interest derivatives are functions of volatility curve. If the shape of volatility curve is constant, the multi-factor model will degrade to single-factor one, and it can reflect the effect of parallel movement of term structure. If someone expects the slope and curvature of term structure will change dramatically, he needs to use the formula under hump volatility curve.
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Lin, Chih-Sheng, and 林志昇. "Modified SVMs Model in Forecasting System." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/53865543747710872939.
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碩士<br>大葉大學<br>工業工程學系碩士班<br>92<br>Support vector machines (SVMs), a novel neural network technique, have been successfully applied in solving nonlinear regression estimation problems. In the real-world time series is a complex and nonlinear dynamic system. Effective time series forecasting is one of the most important topics in the complex time series. Therefore, forecasting system is very complicated and thus difficult to predict. In general, it is very hard for an individual model including SVMs model to complex time series. It is not satisfactory by Cao. Therefore, I modify the SVMs model to deal with the time series forecasting.
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Lo, Jen-Ho, and 羅仁和. "Size-Modified Poisson-Nernst-Planck Model." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/96805650568180052217.
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碩士<br>國立新竹教育大學<br>應用數學系碩士班<br>100<br>The Poisson-Nernst-Planck (PNP) model is a basic continuum model for simulating ionic flows in an open ion channel. The effects of finite particle size on electrostatics, density profile, and diffusion have been a long existing topic in the study of ionic solution [8]. The Poisson equation is derived from Coulomb's law in electrostatics and Gauss's theorem in calculus. The Nernst-Planck equation is equivalent to the convection-diffussion model. An entropy functional that accounts for the finite size effects of ions in electrolytes proposed by Borukhov et al. [1] for the Poisson-Boltzmann (PB) equation has been generalized by Lu and Zhou [8] to the PNP model. We obtain second-order convergent results for the finite size linear PNP model with exact solutions.
For nonlinear finite size PNP model with exact solutions, the numerical errors are almost zero.
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Day, Dennif, and 戴邦芳. "Modified Diagonalization Method for VIP Model." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/62049484615975274219.
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碩士<br>國立交通大學<br>土木工程研究所<br>82<br>Equilibrium network flow can be formulated as Varia- tional
Inequality Problem (VIP) without symmetric assumption.
Diagonalization method is one of the approaches to slove
the equilibrium problem of the VIP model. Although the
Diagonalization method is very easy to implement, the slow
convergence of it's subproblem affects the performance of
the method drastically. In the past, there are two
strategies have been reported to improve it's computional
efficiency on the origional approach : streamlined method
and Harker's method. In this thesis, it is found that the
performance of the streamlined method is very unstable and the
use of Harker's accelerated step can't outperform the
origional approach. As a result of these facts, we present
two accelerated strategies on the former two strategies. The
computional performance of all these strategies that
mentioned above explored by numerical experiment.It is shown
that the strategies we proposed can considerably reduce the
algorithm's computional requirements. We also use these
results to illustrate something that we should notice on
the comparison basis of the computional performance for
different algorithms.
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Chan, Tz-Sheng, and 詹資盛. "A Modified Displaced Dipole Model for Dielectrophoresis." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/86088029166762436591.
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Pai, Pin-Chun, and 白秉錞. "The Modified Coulomb Potential in Bigravity Model." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/34365983082556356263.
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碩士<br>國立清華大學<br>物理系<br>104<br>General Relativity(GR) has a great success to explain some astronomy problem such as universal expansion, Mercury precession, and gravitional lensing. The recent observation of grvitational wave from black hole converge also gives a strong evidence of GR. In the view of field theory, GR can be described as a massless spin-2 field. Physicists have been tried to construct a massive spin-2 gauge theory for a long time, however many of these attempts face the ghost problem, which involves a mode of infinite negative energy thus followed by inconsistence of the theory. A recent massive gravity theory called dRGT model and its extension model called bigravuty theory have been showed that they are ghost-free. The ghost may reappear when one concerns such theory coupling to matter fields, but recent study shows that a class of effective theory in bigravity model can be used to construct ghost-free interaction with matter. In this thesis we first take a brief review of dRGT model and bigravity, and then we solve a series of effective metrics by some known solution of bigravity theory. In the later part we consider a model in which a Dirac fermion couples to a effective metric and interacts with a U(1) gauge boson, which couples to another effective metric. Finally we give the modified Coulomb potential in this model.
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LIN, JUN-MING, and 林君明. "Modified continued-fraction method of model reduction." Thesis, 1985. http://ndltd.ncl.edu.tw/handle/7xttbk.
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Liu, Yen-Ting, and 劉彥廷. "Constructing An Energy Consumption Model using GMDH and Modified Grey Model." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/23402470209948472729.
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碩士<br>國立交通大學<br>工業工程與管理系所<br>101<br>Energy is an essential element of economic development for all countries. Energy consumption has become an important economic index in recent years. Time-series models were frequently used to construct energy consumption model, because it only needs the information of energy consumption. Many studies have developed time-series prediction models for energy consumption using Box-Jenkins models, Autoregressive Integrated Moving Average (ARIMA) or gray models. However, energy consumption would be affected by economic indicators such as population, economic policy, and industrialization of a country, etc. Therefore, a cause-result prediction model is more suitable for forecasting the energy consumption. This study employs GMDH and modified gray model to construct a cause-result prediction model for energy consumption model to enhance the accuracy of existing time-series forecasting models.
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"Bayesian model selection for semiparametric structural equation models with modified group Lasso." 2014. http://repository.lib.cuhk.edu.hk/en/item/cuhk-1291541.
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Selecting an appropriate model is a crucial issue for applying structural equation models (SEMs) in real applications. Due to the model complexity, however, it is quite challenging to perform model selection on semiparametric SEMs with functional structural equations. In this thesis, we propose a modified Bayesian adaptive group Lasso procedure to perform model selection and estimation for semiparametric SEMs. By considering a novel formulation of basis expansions to approximate the unknown functions with certain penalties imposed, we are able to introduce a partial linear structure that combines the advantages of linear and nonparametric formulations for structural equations. The nonlinear, linear, or none structures in structural equations can be automatically detected with the proposed method. In addition, the group Lasso with adaptive penalties not only largely alleviates the model selection difficulties caused by the group effects and correlations introduced by basis expansions of latent variables, but also reduces the bias of traditional Lasso procedures. Simulation studies demonstrate that the proposed methodology performs satisfactorily. The proposed method is applied to analyze a real data set of diabetic kidney disease, which provides us some meaningful insights.<br>在结构方程模型的实际应用中，选择一个合适的模型是一个核心问题。但是由于模型的复杂性，对于含有函数型结构的半参数结构方程模型进行模型选择十分困难。在本文中，我们提出了一种新的贝叶斯自适应群Lasso，并应用它来对半参数结构方程模型同时进行参数估计和模型选择。我们在非参数结构方程模型中引入了部分线性结构，并通过一种新的基底函数展开来近似结构方程里的未知函数。这种结构同时具备了线性模型和非参数模型的优势。本文的方法可以自动识别半参数结构方程模型里面的非线性和线性结构，并筛除不重要的变量。这种带有自适应惩罚的群Lasso不仅减小了传统Lasso方法在估计参数时产生的偏差，而且解决了由潜变量的基底表示导致的组效应和相关性引起的模型选择的困难。由模拟实验的结果可以看出本文提出的方法十分有效。我们还应用所提出的方法分析了一组关于糖尿病型肾病的数据，并得到了一些有意义的结果。<br>Feng, Xiangnan.<br>Thesis M.Phil. Chinese University of Hong Kong 2014.<br>Includes bibliographical references (leaves 51-56).<br>Abstracts also in Chinese.<br>Title from PDF title page (viewed on 18, October, 2016).<br>Detailed summary in vernacular field only.
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Lee, Tung-Sheng, and 李東昇. "A Modified Data Allocation Model for Multidisk Databases." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/06955374642953138912.
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碩士<br>國立交通大學<br>資訊管理研究所<br>85<br>This paper approaches optimal file allocation in a single
processor/multidisk database system, such that allocation can
increase I/O throughput. We introduce the optimal method which
involves N((N-1)/2+M+M(N-1)/2) 0-1 variables for the multidisk
allocation problem with N relations and M disks from Rotem et
al.(1993)[2]. This thesis proposes both modified models which
compare with Rotem's model as following: First modified model
contains NM 0-1 variables and N(N-1)(M+1)/2 continuous
variables.Second modified model contains NM 0-1 variables and N(
N-1)/2 continuous variables.The results show that both modified
models are more computationally effective. Especially, the
second modified model is the most powerful.
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Tu, Yi-Hsuan, and 杜宜軒. "Modified WIC for Order Selection in Autoregressive Model." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/07897542770727722926.
Full textAbstract:
碩士<br>國立成功大學<br>統計學系<br>88<br>We proposed two modified weighted information criteria （WIC）, WICu and WICs, combining AICu with BIC and SICc, respectively, for order selection in autoregressive model. WICu is essentially equivalent to AICu for small sample sizes and to BIC for large sample sizes. Similarly, WICs is equivalent to SICc for large sample sizes and close to AICu for small sample sizes. Both of them are weakly consistent under general conditions. We also compare WICu and WICs with several popular criteria by simulation study. It shows WICu and WICs are better or at least comparable to WIC. In particular, for small samples, WICu and WICs perform as well as AICu and outperform other criteria, and for large sample sizes, WICu and WICs perform as well as BIC and SIC, respectively, and outperform other criteria.
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Pan, Jyun-Sian, and 潘俊賢. "Research On Ohlson’s Model Of Modified Cash Accounting." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/82413331226593621006.
Full textAbstract:
碩士<br>雲林科技大學<br>會計系研究所<br>96<br>This study is research on Ohlson’s model of modified cash accounting as Ohlson [2007]. Because that statement of cash flows lacks a clear “bottom-line” directly comparable to net income to assessment accounting earnings quality and firm’s performance. And management often thinks about firm’s earnings targets or Self-interest Behavior. Then use some methods or procedures to get involved in the financial and influence the result of the financial report, to reach the behavior of the earnings targets. The common tactics are change of discretionary accruals. So the application of the modified cash model is mainly revising to the question of the cash flow statement. Through defining broader of cash in the model can to eliminate all accruals and re-creation cash flow statement content. It works like a regular income statement on a cash and approximate cash equivalent basis. Finally, the derivation of the bottom-line for the cash earnings statement is referred to as MCA’s (net) comprehensive cash earnings.
The difference among the cash earnings and net income is called net accrual. Ohlson inference that the net accrual and growth have positive relation and about application research of modified cash accounting model has not yet at present. Appliance difference of cash earnings and net income to calculate the net accrual. Then this text planned to regard financial materials of electronics industry as the sample of Taiwan. The Empirical data are obtained from the Taiwan Economic Journal Data Bank (TEJ) amounted to 2years since 2005 till 2006. Use statistical regression analysis to test hypothesis. Empirical results of study are the association between net accrual and growth is positive significantly.
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LIN, YU-JUNG, and 林昱融. "Modified Gaussian Mixture Model Applied to Speaker Verification." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/33cbau.
Full textAbstract:
碩士<br>中央警察大學<br>刑事警察研究所<br>104<br>Gaussian mixture model (GMM) is a combination of a plurality of Gaussian probability density function, it can be smoothly approximate the probability density distribution of any arbitrary shape. In various areas of pattern recognition, it has a good recognition results. However, during building the speaker model process, we must determine the parameters of each Gaussian probability density function through constantly iterative calculation, the calculation process is quite complex. This paper presents modified Gaussian mixture model, each characteristic for recognition has its own independent Gaussian probability density function. Since the process without iteration, it can significantly reduce the amount of calculation. And the speaker verification results show that it can still maintain a good recognition results. In this paper, we use Mel frequency cepstral coefficients(MFCCs) as the voice characteristic for speaker verification. The average error rate for speaker verification on Gaussian mixture model is 0.5901%, while it on modified Gaussian mixture model is 1.6700%, the gap between them was 1.0799%. The error rate of two methods during the speaker verification has less difference. But in the speaker model build process, modified Gaussian mixture model does not need to go through an iterative calculation. The calculation ways and time are more simple and faster than Gaussian mixture model. It can also be another consideration of algorithm for more speed and convenience.
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Lin, Chi-hui, and 林季暉. "A Modified Deep Neural Network Speech Enhancement Model." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/8ncc39.
Full textAbstract:
碩士<br>逢甲大學<br>資訊工程學系<br>104<br>Speech intelegibility is more essential than before due to more and more mobile devices need to improve speech quality. This paper develops a more efficient deep neural network (DNN) speech enhancement model based upon Y. Xu’s DNN speech enhancement model, but the structure of DNNs and the learning algorithm of MLPs are modified to achieve an efficient DNN learning. A deep MLP neural net is composed by unrolling a stack of RBMs and adding on a layer to the last stage of the MLP. In the last layer, each neuron has a linear activation function with initial identity weights. Instead of the back-propagation, the resilient propagation learning is employed to train our DNN. These three modifications can speed up DNNs’ learning, that is verified with several experiments using NOIZEUS speech dataset. The key characteristics and mutual relationships among noise intensities, noise types, sentences and human gender, are also identified to reduce the size of training dataset. In order to effectively control parameters of our DNN speech enhancement model, correlations between learning results of DNNs and qualities of enhanced speech are analyzed.
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Liu, Ping-Cheng, and 劉秉承. "Development of a Modified Parallel Computing Watershed Model." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/39228193429753389771.
Full textAbstract:
碩士<br>國立中興大學<br>土木工程學系所<br>104<br>The study developed a next generation hyper-computing watershed model, HERO. The HERO model is based on WASH123D (WAterSHed Systems of 1-D Stream-River Network, 2-D Overland Regime, and 3-D Subsurface Media), which was originally developed by Professor Yeh since 1998. One of the disadvantage of WASH123D is that the dimensions of modeling array are required to be assigned prior to any event simulation. Executed file may need to recompile if their original allocated dimensions are not enough. The other disadvantage is that it will cost too much computational time because the original program is coded in sequential. Therefore this research try to modify the original WASH123D program, to make it became a dynamic allocated array and parallel based computer core.
Simulations indicated that HERO model is no problem to automatically assign program arrays based on any size of study event. It shows more convenient than WASH123D. For parallel tests, HERO model costs less computational time as compared to WASH123D by using the same inputs. And HERO shows the most efficiency performance as 8 cores of central processing units has been applied. And the modeling results revealed very slightly difference to their outputs. They are almost identical. Therefore it can be concluded that HERO model has confirmed can speed up simulations and has not sacrificed modeling preciseness.
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Leu, Chin-Sheng, and 呂金盛. "Integrated Circuit Yield Estimation - Using Modified Poisson Model." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/14407550489981269616.
Full textAbstract:
碩士<br>國立交通大學<br>工業工程研究所<br>82<br>As the complexity of integrated circuits rise, the size of chip increases and the clustering of defects emerges, existing yield models, such as the Poisson model, gradually result in deviation and thus become impractical. Even the negative binominal model which are most popular in the IC industry nowadays since its defect-clustering parameter is related to the chip size and probably may vary with the lot are questioned by many scholars.
The objective of this research is to aim at the drawbacks of present yield models, take defect clustering in account, and then, through statistical analysis, develop a yield model with better yield prediction capability. In this resrearch, we first combine quadrat analysis, hierarchical clustering method, and correlation coefficient method as a defect-clustering analysis procedure to locate defect clusters on wafer maps, identify members of clusters and the relative strength of clustering. Then adopting the concept of wafer partition, we develop a procedure to modify Poisson model with a view to effacing the impact of defect clustering on yield prediction of the poisson yield model.
Through experimental analysis, the clustering analysis procedure proposed by this research are verified to be good at detecting defect clusters, moreover the yield predicton ofmodified Poisson model is more accurate than existing, yield models. Besides, we conclude that yield analysis is applicable in production line, and the strong defect-clustering is likely resulted from mechanical malfunction or human errors.
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Chien-Hung, Liu, and 劉建宏. "A Modified Likelihood Dominance Criterion for Model Selection." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/77127782912644216511.
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Chen, Yung-Chang, and 陳永章. "A Modified Model for Two-Phase Seal Design." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/44775360404456883214.
Full textAbstract:
碩士<br>國立成功大學<br>機械工程研究所<br>81<br>A study is made of phase change in liquid face seals lubricate
under laminar regime.A refined model of the energy equation
for the mixture of two-phase flow is set up to replace the
conven- tional energy equation.Instead of the early model that
liquid ( water) is of a sudden transformed to vapor completely
beyond the saturate point,the energy equation enables us to
predict the thermal properties varying with mixture quality
during flowing process.The influence of fluid density and
dynamic viscosity due to the change of mixture quality on film
temperature and hydro- dynamic pressure is investigated by
differing the entrance and boundary conditions.The present
results in comparison to the one based on the discrete show
significant distinctions in thermal properties at the outlet.
The factors of affecting the lubrication behavior of two-phase
seal include the inlet temperature and pressure,the outlet
pre- ssure,rotational speed and film thickness.This article
will con- centrate on the solutions of mass flow rate,film
thickness, fri- ctional force ,and mixture quality.Moreover,we
make comparison between one-phase and two-phase seal
happening situations. The result appears that changing the
inlet pressure or temperature and under the conditions of
fixed or flexible outlet pressure, temperature distribution
will rise by the increase of rotational speed. The outlet
pressure of flexible outlet pressure rises. And the
position of phase change moves toward the direction of inlet.
This article uses the two-phase flow to deal with the
mixed condition of phase chang,but Lau's discrete model
assume that liquid totally changes to vapor.Thus the pressure
drop of this part is much greater than the two-phase model.
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Tzeng, Ren-Hung, and 曾仁宏. "Application of The Modified DistributedElement Model to Cyclic Ratcheting." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/56255461308047562083.
Full textAbstract:
碩士<br>國立成功大學<br>航空太空工程學系碩博士班<br>91<br>The Distributed Element Model (DEM) in combination with the modified A-F kinematic hardening rule (A-F rule) is capable of adequately describing the uni-axial behavior of cyclic creep (ratcheting) of materials. However, it still has the disadvantage of not being able to describe appropriately multi-axial behavior of cyclic creep. The original A-F rule would lead to a subsequent yield surface which changes its shape during the bi-axial elastic-plastic cyclic loading and would not fit in with the assumption of kinematic hardening rule. Thus we propose two modifications of hardening rule in DEM. Firstly, we modify the original A-F rule to avoid the shape change of the yielding surface. Secondly, we modify the Ziegler kinematic hardening rule to make it proper for modeling of cyclic creep. To verify the modified DEM, we consider the simulation of ratcheting of CS 1070, and the results are compared with experimental results, which are obtained from the literature.
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Chou, Sheng-Kai, and 周聖凱. "A Modified Dynamic Probit Model for Identifying andPredicting Recessions." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/62173187439021626822.
Full textAbstract:
碩士<br>國立臺灣大學<br>經濟學研究所<br>100<br>In this study, we propose a two-step method to circumvent the “announcement lag”
problem of the National Bureau of Economic Research recession dummy, which may
not be suitably dealt with by existing studies on the dynamic Probit model. Specifically,
we first identify the sub-sample of the recession dummy, which is unobserved
because of this problem, using the information contained in certain macroeconomic
indices. Then, we estimate the parameters of the dynamic Probit model based on
the interest rate spread tween ten-year and three-month using the identified recession
probabilities, and make the out-of-sample predictions accordingly. We show
that our model is not only useful for circumventing the announcement lag problem
but also for refining the performance of some alternative models.