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1
Mphahama, Litsoanelo Evodiah. "Institutional constraints to horticulture production and marketing." Thesis, University of Fort Hare, 2011. http://hdl.handle.net/10353/428.
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Lesotho has a land area of about 30.340 square kilometers and is completely surrounded by the Republic of South Africa. Much of the country is mountainous. Its agricultural sector is characterized by low productivity due to erratic climatic conditions, limited arable land and fragile soils with a low water holding capacity. These conditions have proved very detrimental to crop production, rendering agriculture a risky economic activity. Numerous efforts have been made over the years to address the technical constraints confronting the sector, but nothing seems to be changing. The implication is that the technical/climatic factors mentioned above may be only part of the problem. The current situation whereby Lesotho imports nearly 95% of its domestic food requirements is unsustainable, but this desperate picture looks set to worsen with the continuing threats of contracting farm sizes and further declines in farmer participation rates. But this sector has continued to be an important source of household survival and existence. A study was designed and conducted during 2008 and 2009 to identify the institutional constraints to horticulture production in Lesotho, looking specifically at the obstacles to effective production and marketing of horticultural products. A total of 100 farming households were enumerated in four districts of the country, namely Butha Buthe, Berea, Mafeteng, and Thaba-Tseka. A range of institutional and non-price factors in the farming and marketing environment were incorporated in a binary choice model to investigate the degree of satisfaction of the farming households with their previous year’s farming results. To avoid selection bias in the sample, a probit model was chosen, and the Stata-10 software was used to estimate probit coefficients. The results provide indications that property rights, the agricultural extension service, the condition of the physical infrastructure, and distance to markets may be crucial elements threatening the existence of this sector in Lesotho. The difficulties in accessing markets and land remain important institutional constraints to horticulture production and marketing in Lesotho. Recommendations made on these issues include providing more policy support to homestead gardening and for these issues to be incorporated into the Vision 2020 process. Also to be included is the issue of addressing the growing national food insecurity and enhancing Basotho livelihoods in general.
2
Khushk, Ali Muhammed. "The mango production and marketing system in Sindh, Pakistan : constraints and opportunities." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267809.
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Smith, William Corbett. "Production costing with transmission constraints." Ohio : Ohio University, 1989. http://www.ohiolink.edu/etd/view.cgi?ohiou1182517746.
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Pappu, Suguna. "Production planning with due-date constraints." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/13160.
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Borsi, John Joseph. "Cyclic scheduling with spacing constraints." Diss., Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/25475.
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Godber, Olivia Florence. "Livestock production : sustainable development and environmental constraints." Thesis, University of Bristol, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.723443.
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Qutub, Saleh. "Dark matter production after inflation and constraints." Thesis, Lancaster University, 2017. http://eprints.lancs.ac.uk/87382/.
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A multitude of evidence has accumulated in support of the existence of dark matter in our Universe. There are already plenty of dark matter candidates. However, we do not know yet whether any of these candidates constitutes the whole or a part of the dark matter population despite the tremendous experimental efforts. In this thesis, we study several possible dark matter production mechanisms and the corresponding observational and theoretical constraints in the context of inflationary cosmology. Adopting a model-independent approach, we explore the parameter space for dark matter with a mass of order MeV and above showing that only small regions of the parameter space for the popular freeze-out mechanism are still viable. Nevertheless, the regions of the parameter space corresponding to the freeze-in and non-thermal dark matter scenarios are mostly unexplored. We, therefore, zoom into these regions and show that a connection to the inflationary observables can be established, which can help constrain these scenarios. We then consider the parameter space of a sub-eV dark matter candidate, the axion. We show that using the Cosmic Microwave Background radiation constraint on the effective number of relativistic species, an interesting constraint can be placed. This bound arises from the fact that the field whose angular excitations are the axions can be displaced from its minimum during inflation and later decays dominantly into ultra-relativistic, axions which contribute to the effective number of relativistic species. We finally consider the possible production of axion-like particle via non-perturbative effects due to their coupling to inflatons or moduli. We show that this mechanism is efficient only if the amplitude of inflaton/moduli oscillations is initially much larger than the mass scale associated with the axion-like particles. In this case, bounds can be placed on the corresponding parameter spaces.
8
Mingard, P. "Design constraints : An historical approach." Thesis, Brunel University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378449.
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Slifka, Janet Louise Khoenle 1964. "Respiratory constraints on speech production at prosodic boundaries." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/9027.
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Thesis (Ph.D.)--Harvard--Massachusetts Institute of Technology Division of Health Sciences and Technology, 2000.<br>Includes bibliographical references (p. 133-137).<br>This research characterizes the respiratory system dynamics at the initiation and termination of utterances and determines correlations of physiological measures with acoustic cues for these prosodic boundaries. The analysis includes boundaries within a breath as well as boundaries that are aligned with the initiation and termination of exhalation. Simultaneous recordings of the acoustic signal, airflow, esophageal pressure and lung volume were collected during read isolated utterances and short paragraphs. These measures were used to derive estimates of recoil forces of the chest wall, net muscular forces, and the area of the airway constriction. Data are presented from four subjects (two men, two women), all native speakers of American English. Perceptual ratings for initial and final prominent syllables and the locations of pauses within the utterance were also collected. For speech boundaries th.i.t are aligned with breath boundaries, utterance initiation occurs during a rapid transition in muscular effort. Sound begins as soon as conditions permit and these conditions consistently occur during net inspiratory muscular force. Alveolar pressure reaches an initial peak (PpI) that is, in most cases, correlated to the relaxation characteristic of the chest wall. The timing of Pp1 generally coincides with a prominent syllable if that syllable is the first or second syllable in the utterance and precedes later prominences. Pressure at phonation onset is, on average, near 0.3PpI for utterances initiated with a voiced sonorant and is near 0. 8Pp1 for utterances initiated with a voiceless fricative. Phonation termination results from an approximately 3-fold increase in glottal area and a J-3 cm H20 fall in pressure. Irregular fundamental frequency (FO) at the end of voicing, in many cases, does not fit the classical definition of glottalization. Instead, voicing terminates with increasing glottal area, and FO becomes irregular during the increase. In some cases, regular FO resumes as glottal area continues to increase. Distinct respiratory gestures are made at pauses within a breath. The pressure is reduced by 2-3 cm H20, on average, during a period of relatively little volume change. The findings in this research show that the role of the respiratory system in speech production goes beyond a more traditional view of this role as one of simply providing a relatively constant driving pressure during speech.<br>by Janet Slifka.<br>Ph.D.
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Castelo, Daniela Pio Quinto. "Physiological constraints on sound production in Lusitanian toadfish." Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10460.
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Mestrado em Biologia Aplicada<br>O Sucesso reprodutivo dos machos territoriais do xarroco dependem da sua
capacidade vocal. Para a produção de vocalizações são utilizados músculos
sónicos intrínsecos à parede da bexiga-natatória, cuja frequência de contração
pode atingir valores superiores a 100 Hz e são por isso conhecidos como os
músculos mais rápidos entre todos os vertebrados. Com este estudo pretendese
averiguar se a capacidade fisiológica de produção de som é diferente no
inverno e na época reprodutiva, assim como entre juvenis e adultos. Para este
efeito estimulámos o nervo sónico de indivíduos jovens e adultos, no inverno e
na época reprodutiva, com uma sequência de sirenes artificiais simulando a
frequência, duração e taxa de vocalizações naturais. O movimento de
contração do músculo sónico foi registado recorrendo a um transdutor de força
e, simultaneamente foi registado o som produzido. Esperávamos que machos
adultos de verão produzissem sons de maior amplitude e fossem mais
resistentes à fadiga do que machos adultos de Inverno. Não esperávamos
encontrar estas diferenças sazonais em juvenis pré-reprodutivos. No entanto,
esperávamos que machos juvenis no geral produzissem sons de menor
amplitude e fossem menos resistentes à fadiga. Em paralelo à estimulação do
nervo sónico para produção de som, foi realizada a caracterização histológica
e histoquímica das fibras do músculo sónico para cada um destes grupos de
modo a procurar eventuais diferenças estruturais que justificassem as
diferenças esperadas. Machos de verão, tanto adultos como juvenis
demonstraram ter uma melhor performance vocal em termos amplitude de
som. A fadiga muscular parece não variar com a estação do ano mas é, no
entanto, mais acentuada em juvenis. Os resultados referentes ao movimento
de contração do músculo sónico mostram que, para além da contração rápida
correspondente à frequência de estimulação, este músculo apresenta uma
contração lenta e sustida não descrita para outras espécies deste género. Os
cortes histológicos apresentam uma distribuição heterogénea das fibras.
Machos de verão apresentam mais sarcoplasma na época reprodutiva que os
indivíduos de inverno, fêmeas e juvenis. Machos de inverno e verão
apresentam fibras de maior diâmetro que juvenis. As fibras do músculo sónico
têm uma forma poligonal e um centro de sarcoplasma rodeado de miofibrilhas.
A presença de fibras em remodelação e possível divisão em xarrocos adultos
nunca tinha sido descrita nesta espécie. Machos adultos de inverno, assim
como machos adultos de verão que não apresentam uma alta taxa de
vocalizações naturais, aparentam ter fibras mais lentas que machos adultos de
verão com grande performance vocal. Não foi possível determinar o
mecanismo responsável pela contração lenta e sustida do músculo sónico. No
entanto, postulamos que este fenómeno terá um papel importante na
ampliação e radiação do som produzido.<br>Male territorial Lusitanian toadfish depend on their vocal capability for
reproductive success. Sound is produced by a pair of sonic muscles intrinsic to
the swimbladder walls, which contract as fast as 100Hz. and are therefore
considerate to be among the fastest muscles in vertebrates. In this study we
aimed to investigate if the physiological ability for sound production is different
in the winter and in the breeding season, as well as in juveniles and adults. In
that vein we have stimulated the sonic nerve of both adults and juveniles,
during the winter and breading season, with sequences of artificial boatwhistles
simulating the frequency, duration and rate of natural calls. The sonic muscle
contraction movement was recorded using a force transducer. Simultaneously,
we have recorded the produced sound. We expected that the breading adult
males would be able to produce sound of higher amplitude and to be more
resistant to fatigue then the non reproductive winter adult males, however we
didn’t expect to find seasonal differences in pre-reproductive juveniles males.
However, it was expected for juvenile males to produce sounds of lower
amplitude and to be less resistant to fatigue than adult males in general. We
have also examined the histology and histochemistry of sonic muscle fibers to
search for eventual morphological differences between these groups in order to
justify the expected differences in physiological ability for muscle contractions.
Summer males, both adults and juveniles, showed a better performance in
terms of a higher sound amplitude. The muscle fatigue didn’t seem to change
between seasons but is more pronounced in juveniles than adults. The
contraction movement of the sonic muscle results shows the expected fast
contractions that follow the stimulation frequency and also a slow and
sustained contraction that hasn’t been described in any other toadfish specie.
Histological sections of the sonic muscle show fibers that are arranged in
several orientations. Summer males sonic muscle fibers have higher
sarcoplasm area than winter individuals, females and juveniles. Winter and
summer males showed a larger sonic muscle fibers diameter than juveniles.
The fibers were found to have a polygonal shape and a central core of
sarcoplasm surrounded by myofibrils. The presence of remodeling and possible
division fibers in sonic muscle in adult males has never been described in this
species. The sonic muscle of both winter and summer adult males that did not
vocalize at high rates in a natural environment presented slower fibers than
summer adult males that were previously found to be strongly vocal. It was not
possible to determinate the mechanism responsible for the slow and sustained
contraction of the sonic muscle but we postulate that this phenomenon has an
important role in sound amplitude and radiation.
11
Goncalves, Vitor Salvador Picoa. "Livestock production in Guinea-Bissau : development potentials and constraints." Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259470.
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Tai, Chia-Hung C. "A stochastic project scheduling problem with resource constraints /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9842569.
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Keas, David G. "Analysis of production constraints at NADEP Alameda : a TQL approach /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1993. http://handle.dtic.mil/100.2/ADA272416.
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Mills, Annamaria. "Understanding constraints to cocksfoot (Dactylis glomerata L.) based pasture production." Phd thesis, Lincoln University. Agriculture and Life Sciences Division, 2007. http://theses.lincoln.ac.nz/public/adt-NZLIU20070717.161658/.
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This research examined the mechanisms by which temperature, water availability and nitrogen (N) affect the dry matter (DM) yield potential of cocksfoot (Dactylis glomerata L.) dominant pastures. The experiment was a split plot design with main plots of fully irrigated (I) or dryland (D), sub-plots of N fertiliser at 800 kg N/ha in 2003/04; and 1600 kg N/ha in 2004/05 (+N) or 0 kg N/ha (-N). The potential environmental yield of an established 8 year old cocksfoot dominant pasture was 21.9 t DM/ha/y from I+N pastures compared with 9.8 t DM/ha by I-N pastures and 15.1 t DM/ha/y by D+N pastures. The lowest yields were from dryland pastures with no N which produced 7.5 t DM/ha/y in 2003/03 and 5.0 t DM/ha/y in 2004/05.
The effect of seasonal temperatures on the DM production, when periods of water stress were excluded, was quantified using thermal time accumulated above a base temperature of 3°C as 7.0 kg DM/°Cd/ha for N fertilised pastures and 3.3 kg DM/°Cd/ha for pastures with no N.
The 2.5 t DM/ha difference in yields of D-N pastures in 2003/04 and 2004/05 was the result of the duration, extent and timing of the water stress period. In both years the critical limiting deficit (DL) was calculated as 78 mm from the soil moisture deficit in the 0-0.8 m soil layers. Beyond DL yield decreased at a rate of 1.45%/mm in +N and N pastures, relative to fully irrigated control pastures.
Yields of D+N and D-N pastures were similar during periods of water stress with 0.4±0.1 t/DM/ha produced during the rotation ending 30/12/2003. This was less than from either the I-N (1.2 t DM/ha) or I+N (3.5 t DM/ha) pastures due to the reduction in the amount of photosynthetically active radiation intercepted by the canopies of the dryland pastures. However, in the rotation ending 2/5/2004, after autumn rain alleviated drought conditions, yield of the D+N pasture was 2.1 t DM/ha compared with 1.7 t DM/ha by I+N pastures.
The effect of N on yield was described using a nutrition index which showed that as DM yield increased N% in the herbage declined. This is a function of the ratio between metabolic and structural N requirements rather than caused by ontogeny alone. Specific leaf N was determined at two harvests and appeared constant at a given point in time (1.0-1.6 g N/m² leaf). In contrast, specific pseudostem N increased from 0.8-1.0 g N/m² pseudostem at an NNI of 0.4 in N pastures to 2.6-3.0 g N/m² pseudostem at an NNI of 1.2 in the +N pastures.
Differences between the yields of +N and N pastures were caused by differences in radiation use efficiency (RUE) as determined by the linear relationship (R²=0.76) between RUE and the nitrogen nutrition index (NNI).
In this thesis, empirical relationships for the effects of temperature, water availability and N were derived and the physiological mechanisms which underlie these descriptions were identified. These relationships provide clear and simple explanations of the effects of environmental variables on the productivity of cocksfoot based pastures which will enhance understanding of the benefits and limitations of cocksfoot, particularly in dryland farming systems.
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Gungulo, Ana Lidia. "Expanding pulse production in Mozambique : identifying constraints and new strategies." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/41117.
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Pulses (common beans and cowpeas) provide a major alternative source of protein, and the rapid rise in food prices has led to an increase in the consumption of inexpensive pulses. The slow growth in pulse production has, however, led to a decline in availability. Thus, to overcome this decline in production, this study concern in expanding pulse production in Mozambique by using the agricultural research survey known as TIA. In addition, this study identified and analysed the critical drivers influencing production, as well as constraints and opportunities to expand pulse production in Mozambique.
In studying the participation of smallholder farmers in pulse markets, the Heckman two-step approach was applied to avoid sample selection bias. In the first step a Probit model was estimated to capture the household’s decision of whether or not to participate in the market. The second step comprised of an OLS estimation to determine the significance of variables that contribute to the level of pulse sold. At national level, results indicate that the majority of households receive price information, but few households receive information on fertilizers and improved seed use. Most households also have poor access to credit and improved extension services, and low levels of membership of agricultural associations. A very small percentage of household farmers are engaged in pulse production, with male farmers more dedicated to the production of common beans and female farmers more dedicated to the production of cowpeas.
In terms of market participation, the results reveal that female-headed households are less likely to participate in pulse markets. The critical factors that discourage entry into the pulse market are distance to the market and yield loss. The factors that give incentives to smallholders to participate in the pulse market are land size, price information and pulse price.
The trade volume of common beans is relatively high and is affected by land size, pulse price and price information. In contrast, the trade volume of cowpeas is highly affected by bicycle ownership and ownership of livestock for animal traction. Cowpea prices also have a positive effect on the volume of cowpeas sold. Yield loss is a major factor that negatively affects the pulse trade, while land size has a negative effect on the volume of cowpeas sold.
Land availability and price information provide good opportunities, in Mozambique, for expanding pulse production. The expansion of pulse production is however constrained by household access to public goods and services such as extension services, credit and membership to an agricultural association. Moreover, the expansion of pulse production in the country is also constrained by the absence of the use of productive technologies such as improved seed and fertilizer.
Based on the results of the study, the recommendations are to expand extension services, improve access to improved technology, facilitate access to agricultural finance, and improve infrastructure and storage facilities. This would facilitate and give incentive to smallholder to expanding pulse production in Mozambique.<br>Dissertation (MSc Agric)--University of Pretoria, 2013.<br>gm2014<br>Agricultural Economics, Extension and Rural Development<br>unrestricted
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Vanit-Anunchai, Chuthaporn. "Possibilities and constraints of marketing environmentally friendly produced vegetables in Thailand." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=982597886.
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Gruber, Wolfgang. "Modeling and transformation of workflows with temporal constraints." Berlin : Amsterdam : Aka, Akademische Verlagsgesellschaft ; IOS Press, 2004. http://catalog.hathitrust.org/api/volumes/oclc/57677828.html.
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Gress, Tobias. "South African Rooibos industry : opportunities and constraints with special reference to the German consumer market." Master's thesis, University of Cape Town, 2004. http://hdl.handle.net/11427/5818.
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Includes bibliographical references.<br>Over the last decade a South African product, namely Rooibos, has conquered the German consumer market. It initially started as a small trend amongst health conscious people, developing into a staple product, to being difficult nowadays to imaging Rooibos not being available for sale. As Rooibos gained popularity on the extremely competitive German food market, marketing strategies had to change accordingly. To reach the mass market, it was necessary to market Rooibos at the discounters and supermarkets, important for the German grocery industry. Advertising also played an important role as through TV and pring media many consumers can be approached and therefore product awareness increased.
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Xu, Qiming. "Processing constraints on segmental and suprasegmental production in a foreign language." Thesis, University of Ottawa (Canada), 1991. http://hdl.handle.net/10393/7623.
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Erbaugh, J. Mark. "Determinants of agricultural production constraints in Uganda: a socio-ecological approach /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487867541730366.
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Russ, Katheryn Niles. "Pinpointing production constraints faced by female-headed households in rural Malawi." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-10022008-063206/.
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Malherbe, Johannes Louw. "Scheduling program based on the theory of constraints." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53581.
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Thesis (MEng)--Stellenbosch University, 2003.<br>ENGLISH ABSTRACT: The goal of this thesis is to provide a stepping-stone for the design and development of a software
package that implements the Goal System Algorithm, based on the Theory of Constraints (TOC).
This includes the complete description and explanation of the Goal System Algorithm (GS), as
well as the partial implementation of this algorithm using Microsoft Access as a Database
Management System (DBMS) and Microsoft Visual C++ as programming language. The main
development effort was put into the development of a scheduling algorithm and the
implementation of a data structure that lies at the core of this algorithm.
The reason for the development of such a package is that it will aid a production manager,
working in a small to medium size job-shop, in generating a schedule for production that
will increase throughput, while simultaneously reducing both inventory and operating
expense thereby generating profits and cash flow.
With regard to this thesis and the overall project goal the following have been achieved.
1. The complete project has been researched, scoped and each step has been explained.
2. The complete program structure has been defined and broken into two separate modules;
the Data Mining and Conversion Module and the TOC Scheduling Algorithm.
3. The database containing all the MRP data necessary for scheduling has been designed
and implemented using a MS Access database with an ODBC connection. An ODBC
connection to the database was used so that a smooth transmission to other database
management systems can be made.
4. The TOC Scheduling Algorithm has been developed and the following have been
implemented:
• A basic user interface has been created for the insertion of all the user input and to
display the constraint schedule.
• A data structure called a linked list has been developed and used to store the
scheduling data in memory.
• The complete GS algorithm had been researched and explained.
• The GS algorithm has been and implemented and tested up to the point where it
schedules the constraint.
• The pseudo code for the part of the GS algorithm that was not implemented has been
documented and included in this report.
More development needs to be done and a proper Graphical User Interface must also be created
to complete this project, but after completion a Toe software package will exist that is
completely unique in South Africa and the market potential for this package will be considerable.<br>AFRIKAANSE OPSOMMING: Die doel van hierdie tesis is om die grondslag te skep vir die ontwerp en ontwikkeling van 'n
sagteware pakket wat Goldratt se Doel Sisteem Algoritme, gebasseer op die 'Theory of
Constraints', implementeer. Dit sluit die gedetaileerde beskrywing van die Doel Sisteem
Algoritme in en 'n gedeeltelike implementasie van die algortime, deur gebruik te maak van 'n
Microsoft Access databasis as databasis bestuur sisteem en Microsoft Visual C++ as 'n
programerings taal. Die hoof klem is gelê op die ontwikkeling van die skedulerings algortime en
die implementasie van die strukture wat deel van die kern uitmaak van die algoritme.
Die hoof rede vir die ontwikkeling van so 'n pakket is sodat dit 'n produksie bestuurder van
'n klein to medium grootte vervaardigings besigheid sal help om 'n skedule vir produksie
the genereer wat die vloer se deurset sal verhoog, terwyl dit voorraad en operasionele kostes
sal verlaag. Met ander woorde dit sal die besigheid help om meer geld te maak huidiglik en
in die toekoms.
Met betrekking tot die tesis en die algehele projek doel is die volgende bereik:
1. Die hele projek is nagevors, uit een gesit en verduidelik.
2. Die hele program struktuur is gedefinieer en opgebreek in twee aparte modules; nl. die
'Data Mining and Conversion Module' en die 'TOC Scheduling Algorithm'.
3. Die databasis wat al die nodige MRP inligting bevat wat benodig word vir skedulering is
ontwerp en geimplementeer deur gebruil te maak van 'n MS Access databasis met 'n
ODBC konneksie. Daar is van 'n ODBC konneksie gebruik gemaak sodat as die nodig
is, daar sonder enige moeite na ander databasis bestuurs sisteme oorgeskakel kan word.
4. Die 'TOC Scheduling Algorithm' is onwikkel en die volgende is geimplementeer.
• A basisse gebruikers vlak is ontwikkel sodat al die nodig invoer data in die program
ingevoer kan word.
• 'n Geskakelde lys is ontwikkel en gebruik as die data struktuur om al die
skedulerings informasie in geheue te stoor.
• Die Doel Sisteem algorimte is in sy geheel verduidelik en gedokumenteer.
Die Doel Sisteem algoritme is geïmplementeer tot op die punt waar dit die primêre
bottelnek skeduleer.
• Die pseudo kode vir die deel van die GS algoritme wat nie geimplementeer is nie is
uitgelê in ingesluit as deel van die verslag.
Verdere ontwikkeling word nog benodig en 'n beter gebruikers vlak moet nog geskep word om
die projek te finaal afte handel, maar na dit gedoen is sal daar 'n TOe skedulering pakket bestaan
wat heeltemal uniek is tot Suid-Afrika en 'n groot mark potensiaal sal hê.
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Cohen, Andrew Connolly. "Advertising as Cultural Production." Thesis, Yale University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10783444.
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<p> This dissertation presents three sociological essays analyzing advertising agencies through the lens of cultural economic sociology. Drawing on 12 months of ethnographic research and 81 interviews across four American advertising agencies, this dissertation presents three explorations of how meaning-making processes are central to the various processes of advertising production. </p><p> The first essay explores how market intermediaries help other market actors see the market and their opportunities for action within it. The essay article illustrates how advertising practitioners provide their clients with visions of what the market is and what opportunities for action lie within it, developing advertising campaigns to match that vision. These accounts of the market and its opportunities are dynamically negotiated, both reflecting and shaping the identities of the clients, their target audiences, and the intermediaries themselves. Because intermediaries dramaturgically perform these interpretations of the market for their client in micro-level interactions, they must also deal with disagreement, contestation, and negotiation over their visions of the market.</p><p> The second essay explores how advertising agencies consume and produce consumer research. Taking a relational approach to the production of advertising, this essay conceives of the work agencies do as part of establishing viable exchange relationships with their clients in which the client exchanges money for the agency's ideas for campaigns. The analysis shows how agency employees—in particular, account planners—first negotiate what kinds of consumers matter with their clients, then produce consumer research in ways that helps them generate particular types of qualitative materials. Agency employees then use those materials to craft aesthetic, material representations of the consumer that can serve as exchange media to facilitate the broader exchange of campaign ideas and money.</p><p> The third essay takes adopts a pragmatic sociological framework to examine conflict in advertising agencies, suggesting such conflicts can be better understood as inevitable clashes between different regimes for justifying the value of advertising work. The article examines three such regimes that advertising practitioners use to justify the work they do: the regime of <i> partnership</i>, the regime of <i>expertise</i>, and the regime of <i>brokerage</i>. Each regime supposes its own definition of what is good advertising work, how that work is evaluated, and how that work should be done, as well as what relationships there should be between the agents who do the work and their clients. Furthermore, each regime has its critiques of the others, and compromises between regimes are unstable and temporary. The different types of conflicts that arise from clashes between these regimes can be understood as the outcome of threats to the different social bonds supposed by each of those regimes.</p><p> These articles are prefaced by a broad discussion of the intellectual projects of economic sociology, in which the literature is divided into two camps: one that studies the economy <i>of</i> culture, and one that studies the economy as culture. After reviewing the different conceptualizations of production and consumption in each, as well as considering the role of materiality and the relationship between the economic and the social, this discussion concludes with a commitment to studying the economy as the enactment of cultural intentions, opting for an analytical strategy that preserves the relative autonomy of culture in exploring how narratives and codes structure economic activity.</p><p>
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Halforty, Gail Avril. "Constraints to students' participation in sport on a formalised level: implications for marketers." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1012120.
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The rate of obesity has risen dramatically over recent years and is an epidemic in many countries. School pupils and university students are no exception to this. The negative effects physically, mentally and emotionally of being overweight are detrimental to one’s quality of life. It is therefore critical to encourage pupils and students to participate in physical activity. Formalised sport is a key component of encouraging physical activity. The habits learnt in childhood and early adulthood are often carried through for the rest of one’s life. The benefits of participating in sport need to be promoted extensively to the students, as research has shown students that participate in sport are not only healthier but achieve better academic results. This study examined the constraints to students’ participation in formalised sport. The empirical data was collected by means of a survey, using self-administered questionnaires distributed to students on the three Summerstrand campuses at the Nelson Mandela Metropolitan University in Port Elizabeth. Two hundred and eighty three usable questionnaires were received. Time and scheduling was found to be the most constraining factor to participation in sport. I am too busy with my university studies attracted the highest mean score of all the items on the questionnaire. It is recommended that: • sport organisers at NMMU emphasise to the students the benefits of regular participation in physical activity; • the effectiveness of the current NMMU sport programmes and accessibility be further investigated as only 18 per cent of the students in 2011 were participating in sport programmes at NMMU; • time management skills be taught to the NMMU students as the Time and scheduling constraint was the most profound constraint to participation in formalised sport; • NMMU academic staff work more closely with the staff at the University Sport Bureau to promote regular sport participation and to disseminate sport related information that could promote being more actively involved in sport; and • relevant introductory sport programmes and more internal leagues be offered, that gently introduce various sport codes to the students.
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Kasljevic, Ivan, and Emir Mustafic. "Theory of Constraints och Lean Production i High-mix Low-volume företag." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-28403.
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Konkurrensen i tillverkningsföretag ökar ständigt och detta medför att det ställs hårda krav på produktkvalitet och förmågan att leverera produkter i tid. För att företag ska kunna nå upp till dessa mål krävs utveckling och ständiga förbättringar i takt med den växande marknaden. Detta uppnås på olika sätt men ett vanligt sätt är att arbeta med förbättringsmetodiker. Val av förbättringsmetodik beror på företagets tillverkning, kunskap inom företaget och resurser inom företaget. Att välja förbättringsmetodik anpassat till den egna organisationen är väldigt svårt för många organisationer och många organisationer ställer sig frågan: ”Vilken metod passar bäst för den egna organisationen?”. Målet med examensarbetet är att undersöka om och hur Lean Production och Theory of Constraints kan användas i företag med high-mix low-volume produktion. Med hjälp av en litteraturstudie och en fallstudie har följande frågor besvarats: 1) hur Lean Prodution och Theory of Constraints används i en HMLV produktion och hur dessa kombineras, 2) hur produktionsflödet styrs enligt Lean Production och Theory of Constraints för att effektivisera en produktionsprocess i ett HMLV företag, 3) vilka personliga paradigm och policys det uppstår enligt Lean Production och Theory of Constraints i HMLV företag och vad sambandet mellan dessa och kvalitet är. Resultat från litteraturstudien och fallstudien visar att Lean Production och dess verktyg går bra att använda kombinerat med Theory of Constraints i HMLV företag med vissa undantag. Dessa undantag är dock inga undantag som säger att Lean Production och dess verktyg inte går att använda i HMLV företag i kombination med Theory of Constraints. Dessa undantag behöver endast anpassas för HMLV produktion. Resultaten visade också att standardiserat arbete i en produktion har en avgörande roll när Lean Production och Theory of Constraints används. Standardiserat arbete bidrar till att fortsatt utveckling och implementering underlättas. Resultaten visar även på att produktionsflödet kan anpassas med hjälp av metoder inom Lean Production och Theory of Constraints och att detta göras bäst när dessa två metodiker kombineras. Vidare visade resultaten att nya investeringar i form av ny utrustning inte är nödvändiga i många fall. Detta förutsätter att flaskhalsar, så som personliga paradigm och policys, identifieras. Resultaten visade även att kvaliteten är direkt kopplad till dessa två flaskhalsar och att en investering i ledarskap är att föredra.<br>Competition between manufacturing companies is constantly increasing and this causes high demands on product quality and ability to deliver products in time. For companies to be able to reach these goals it is necessary to work with development and continuous improvements and respond to the current pace of the market. This can be achieved in different ways, but a common method is to work with improvement methodologies. Selecting which improvement methodologies to use depends on a company’s manufacturing, knowledge, and resources. Many organisations find it difficult to choose improvement methodologies for their particular organisation and ask the question: “Which method is best suited for our organisation?”. The goal of this study is to examine whether and how Lean Production and Theory of Constraints can be utilized in companies with high-mix low-volume production. By performing a literature review and a case study the following questions have been answered: 1) how Lean production and Theory of constraints are utilized in a HMLV production system and how they can be combined, 2) how the production flow is controlled according to Lean Production and Theory of Constraints to improve the efficiency of a production process in a HMLV company, 3) what personal paradigms and policys arise according to Lean Production and Theory of Constraints in HMLV company and what the relationship between these and quality is. Results from the literature review and case study show that Lean Production and its tools are possible to use in a combination with Theory of Constraints in HMLV companies with some exceptions. However there is no exceptions saying that Lean Production and its tools combined with Theory of Constraints can not be utilized in HMLV companies. These exceptions only need to be adjusted for HMLV production. The results also showed that standardized work in a production process plays a crucial role when combining Lean production with Theory of Constraints. Standardized work contributes to facilitation of further development and implementation. The results show that the production flow can be adjusted using methods from Lean Production and Theory of Constraints, and that this is done best by combining these two methodologies. Furthermore, the results showed that in many cases new investments in the form of new equipment are not necessary. This assumes that bottlenecks, such as personal paradigms and policies are identified. The results showed that quality is directly linked to these two bottlenecks and that an investment in management is preferable.
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Ghazi, Nezami Farnaz. "Sustainability based decisions in manufacuring systems with production, reliability, and maintenance constraints." Diss., Wichita State University, 2013. http://hdl.handle.net/10057/10608.
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Murphy, Carol (Carol Anne) 1961. "Gender constraints to increased agricultural production faced by rural women in KwaZulu." Master's thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/15959.
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Bibliography: pages 116-124.<br>It is well known that women are constrained by their gender role, which is imposed on them by the gender relations they experience. This role allocates them the direct responsibility for maintenance of the household and subjects them to patriarchal relations of male domination and female subordination. There is little understanding, however, of how gender-specific constraints operate. This study records the gender-specific constraints affecting the lives of black, rural women in a homeland in South Africa (KwaZulu). An analysis is given of the extent to which these gender-specific constraints affect the agricultural productivity of these women. An integrated methodology, combining elements of qualitative observations, key-informant interviews and quantitative surveys was used to identify gender-based constraints to agricultural production experienced by rural women in the study area (the Nhlangwini Ward, Umzumbe District, southern KwaZulu). This information revealed that the lives of women in the Nhlangwini Ward are severely affected by gender-specific constraints that arise out of: their involvement in various activities that constitute their multiple work role (survival tasks, household tasks and different resources (land, income generation); their access to capital and training) and their perception of their gender role and the patriarchal relations they experience. Women in the ward adapt to these constraints by: using child labour and hired labour to assist them in conducting survival tasks and household tasks; allocating some shopping (for clothes) to male household members who have greater access to urban centres; membership of community gardens to gain access to arable land and agricultural expertise; hiring private arable land for farming and adopting poultry farming as a favoured agricultural activity. Recommendations are made for types of projects and policy changes that could work to overcome these constraints and the broader subordination of women in rural areas. As gender and rural development is a pioneering research field in South Africa, more research of this type is urgently required because at present the development process takes little cognisance of gender issues.
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Lin, Wei. "Production Scheduling of an Open-pit Mining Complex with Waste Dump Constraints." Thesis, Curtin University, 2021. http://hdl.handle.net/20.500.11937/88095.
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The research work aims to solve the production scheduling problem for open pit mining complexes. It establishes a Mixed-Integer Programming (MIP) model that maximises the net present value of future cash flows and satisfies reserve, production capacity, mining block precedence, waste disposal, stockpiling, and pit sequence constraints. The model is validated and implemented with real-world case.
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Humlová, Jana. "Marketingová strategie Musical production." Master's thesis, Vysoká škola ekonomická v Praze, 2013. http://www.nusl.cz/ntk/nusl-198472.
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This thesis deals with an arts marketing with a focus on musical theater. The theoretical part defines basic elements of the marketing process, with the main emphasis placed on marketing mix and its specifics in context of musical production. In this part of the thesis there is also description of marketing research. In favour of smooth transition to practical part, at the very end of theoretical part there is a summary of main competitors. The practical part is focused on the company operating in the theater Hybernia and on its marketing and communication activities. Based on the theoretical presumptions the marketing research had been realized and it had examined the customers of this company. The output of the research, analysis of the marketing mix and analysis of the competitors serve as basis for creating innovations in marketing mix.
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Huynh, Thi Thu Thuy. "Capacity constraints in multi-stage production-inventory systems applying material requirements planning theory /." Linköping : Department od Production Economics, Linköping Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-7355.
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Vassalos, Michael. "ESSAYS ON FRESH VEGETABLE PRODUCTION AND MARKETING PRACTICES." UKnowledge, 2013. http://uknowledge.uky.edu/agecon_etds/12.
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Commercial fresh vegetable production is one of the most rewarding and risky farming activities. The price and yield variations throughout the production year, the special characteristics of fresh vegetable produce (i.e. perishability), and the changing consumer demands are some of the factors contributing to the increased uncertainty faced by vegetable producers. This dissertation combined mathematical programming and econometric techniques to: 1) investigate the optimal production and marketing practices under different price distribution information scenarios, risk aversion levels and marketing outlets and 2) examine growers’ preferences as well the effect of risk aversion levels and growers’ risk perception on the choice of marketing contracts. Specifically, the following three modeling approaches were adopted in order to achieve the dissertation objectives: 1) quadratic programming under a mean-variance framework, 2) discrete choice experiments and 3) a combination of quadratic and integer programming embodied in a meanvariance framework. The findings indicate that optimal production practices and the resulting net returns are substantially influenced not only by the choice of marketing channel but also by growers’ risk aversion levels as well as price knowledge. Furthermore, regarding the choice of marketing contracts, the results highlight the existence of heterogeneity in preferences and illustrate the importance of certification cost, in line with the previous literature. Lastly, the findings indicate that risk aversion and risk preferences do not play a significant role in the choice of contractual agreements by farmers.
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Chow, Po-fun Wendy, and 周寶芬. "Marketing of local drama production in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31268730.
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Chow, Po-fun Wendy. "Marketing of local drama production in Hong Kong /." Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19876555.
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Huynh, Thi Thu Thuy. "Capacity Constraints in Multi-Stage Production-Inventory Systems : Applying Material Requirments Planning Theory." Doctoral thesis, Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-7355.
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In this thesis, capacity-constrained aspects of multi-level, multi-stage productionplanning are investigated. The aim has been to extend Material Requirements Planning Theory (MRP Theory) to cover more general problems dealing with capacity constraints, in particular when non-zero lead times are present and the processes take place in continuous time. MRP Theory deals with multi-level production systems with multiple items taking place either within a discrete or continuous time framework. External demand is considered either deterministic or stochastic. Lead times are assumed to be given constants, and the Net Present Value Principle has been applied as the objective function. The Bill-of-Materials, capturing component as well as capacity requirements, in volume as well as in advanced timing due to lead times, has been described using a generalised input matrix involving Laplace transforms or z transforms. In order to be able to apply Dynamic Programming as a solution method, the system state has been defined and designed in terms of a matrix, in which historical values of cumulative production and cumulative demand are given state variables. A high power computer has been used to calculate solutions to numerical examples. Moreover, this thesis examines the fundamental equations of MRP Theory in order to analyse the possibility to obtain closed-form expressions for the time development of the system, when standard ordering rules of MRP are applied. In addition, capacity-constrained production planning problems and procedures in a paper mill have been surveyed and are presented in the form of a case study.
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Piccolo, Andrea [Verfasser]. "Continental crust production during the early Earth: Constraints from geodynamic models / Andrea Piccolo." Mainz : Universitätsbibliothek Mainz, 2019. http://d-nb.info/1188356739/34.
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Suzuki, Kuniaki. "Investigation into the constraints to dairy cattle health and production in Northern Vietnam." Thesis, Royal Veterinary College (University of London), 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417822.
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Lauridsen, Rasmus Bach. "Stoichiometric constraints on secondary production in a nutrient rich headwater stream food web." Thesis, Queen Mary, University of London, 2012. http://qmro.qmul.ac.uk/xmlui/handle/123456789/2523.
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Most consumers maintain body tissue Carbon:Nitrogen:Phosphorus within narrow constraints, despite ratios often varying markedly among basal resources. Elemental quality may be a major factor governing resource selection by, and production of, consumers. Elemental imbalances between resources and consumers could constrain the flux of matter through food webs. Here the aim was to characterise and quantify the distribution and flux of C, N and P in a headwater stream food web. The stream water was nutrient rich (TP=208 μg L-1; TON=7 mg L-1), resulting in low C:N and C:P of basal resources. Nevertheless, elemental imbalances were evident between consumers and basal resources, particularly for organisms feeding on detritus. Although taxonomic differences existed, detritivores were typically depleted in N and P compared to taxonomically related species. Detritus comprised 97% of the biomass entering the food web, resulting in excess consumption of C and, therefore, stoichiometric imbalances. 75% of the tree canopy was removed from the heavily shaded experimental reach, resulting in a significant increase in benthic algae and a subsequent reduction in elemental imbalance and an increase in secondary production. It appears that stoichiometric constraints on secondary production were relaxed by increasing the availability of high quality resources in this detritus based food web. Most previous studies have calculated imbalances based on diet assumed from trophic level or functional feeding groups; however, the results presented here from gut contents analysis highlight the potentially erroneous interpretation of assumed measures of imbalance. Furthermore, static measures of elemental imbalances, i.e. the difference in elemental quality between consumers and their resources, do not give an adequate measure of these constraints. The dynamic measures explored here, give an assessment of relative rates of supply (rate of consumption) and demand (from metabolism). Such dynamic measures are crucial to understanding the role of ecological stoichiometry in determining key ecosystem processes.
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Baker, Jonathan (Jonathan Early). "The impact of including water constraints on food production within a CGE framework." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68446.
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Thesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2011.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 73-76).<br>This research explores the long-term relationship between water resources, irrigated land use change and crop production within a computable general equilibrium modeling framework. The modeling approach is developed on a variant of the MIT Emissions Prediction and Policy Analysis (EPPA) model that describes three agriculture sectors-crops, livestock and managed forestry-five land types-cropland, pasture land, managed forest land, natural grass land and natural forest land-and conversion among these land types. I further develop this framework by describing crop production as the aggregate production of crops grown on irrigated and non-irrigated cropland. Water resources, through the parameterization of regional irrigable land supply curves, limit conversion to irrigated cropland and thus constrain regional crop production. Land use change, dynamics of irrigated land and regional water demand and crop production are investigated with the new model structure. Non-irrigated cropland is found be expanding faster than irrigated cropland. However, regionally, competition from biofuels for non-irrigated cropland may drive further expansion in irrigated cropland. Regarding water demand, most regions are withdrawing a very small share of their renewable water resource. Crop production levels are compared to results from a model that does not include water constraints. Global crop production declines a small amount with the most significant regional effect observed in the Middle East where regional water constraints have severely restricted the area by which irrigated cropland can expand. This result highlights the importance of considering water resource constraints in regions that experience, or might experience, shortages of water.<br>by Jonathan Early Baker.<br>S.M.in Technology and Policy
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Clemente, Lucia. "Influence of defoliation and environmental constraints on tanin production in Thamnochortus insignis Mast." Thesis, University of Cape Town, 1991. http://hdl.handle.net/11427/25954.
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Schwartz, Thomas J. "Production and direct marketing of sweetpotatoes in southern Illinois /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1203549821&sid=10&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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La, Trobe Helen Louise. "Perceptions of sustainable food production through direct marketing schemes." Thesis, University of Kent, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274344.
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Paxton, Heather. "Locomotor design constraints and musculoskeletal compromises in the broiler chicken." Thesis, Royal Veterinary College (University of London), 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.572144.
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Goel, Saumya. "Dynamic Probabilistic Lot-Sizing with Service Level Constraints." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306865399.
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Mirante, Nicole. "Combined constraints in speech production : evidence from linguistic data, oral poetry, and cultural dynamics." Thesis, University of British Columbia, 2006. http://hdl.handle.net/2429/30956.
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This work describes a model of speech production based on the central role
exercised by a speaker's working memory. It is proposed that speakers make intensive
use of their working memory when planning, composing and uttering speech, and that a
speaker's working memory is guided in its composition processes by an array of co-occurring
cues, or constraints, which determine the selection of chunks of utterances in
memory. The constraints are: semantic activation, imagery (i.e. the activation of detailed
semantic, visual and spatial information), syntax, speech rhythm, prosody and sound
repetitions. Speakers are exposed to the perception of environmental information and to
others' speech, and these inputs determine the co-occurring activation and the selection
of mnemonic data according to the constraints outlined. Evidence for the model is drawn
from linguistic material, research on the cognitive psychology of oral literatures, and
studies in social psychology and cultural information transmission.
The model stems from criticism that I direct to the concept of language as it is
understood in modern linguistics. It will be shown that the assumptions on which current
theories of language rest are at odds with recent developments in philosophy and
communication studies. It will be argued that the proposed model is not only more
theoretically sound, but also more adequate to describe speech as it is produced by real
speakers.<br>Arts, Faculty of<br>English, Department of<br>Graduate
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Olivares-Gonzalez, Enrique. "Physiological constraints on production of the Indian white prawn Fenneropenaeus indicus (H. Milne Edwards)." Thesis, Bangor University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369826.
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Matabwa, Charles January. "Nutrient and water constraints to crop production in the savanna soils of Mubangwe, Malawi." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304248.
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Palmerio, Jesse. "Gamma-ray burst production efficiency from stars : constraints from population models and host galaxies." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS471.
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Les sursauts gamma (GRB) sont de brèves bouffées de rayonnement électromagnétique à haute énergie provenant de l'espace, formés dans un jet ultra-relativiste à l'issue de la naissance d'un trou noir stellaire. Une sous-classe de GRB dite longs (LGRB) s'est avérée associée à l'effondrement de coeur d'étoiles massives, ainsi les LGRB ont été suggérés comme des traceurs prometteurs de la formation stellaire jusqu'aux premiers ages de l'Univers. Cependant, les coeurs stellaires ne donnent pas tous lieu à des LGRB, car ces derniers sont des événements rares nécessitant des conditions particulières pour être formés. Dans cette thèse, nous étudions un ingrédient essentiel pour utiliser les LGRB en tant que traceurs de formation stellaire: l’efficacité des LGRB, définie comme la fraction des effondrements de coeur qui forme un LGRB. Dans la première partie de la thèse, nous présentons un modèle statistique de population développé pour reproduire trois contraintes observationnelles soigneusement sélectionnées. Ce modèle nous permet de contraindre la population intrinsèque de LGRB et de montrer que l'efficacité des LGRB augmente avec le redshift. La deuxième partie de la thèse est consacrée à l'identification de facteurs affectant l'efficacité des LGRB par l'étude d'un échantillon complet et sans biais de LGRB à 1 < z < 2. Nous étudions les environnements dans lesquels se forment les LGRB en étudiant les propriétés de leurs galaxies hôtes et en les comparant aux galaxies à formation d'étoiles. Nous montrons que la métallicité est un facteur déterminant régissant l’efficacité des LGRB. Ces résultats combinés offrent un pas de plus vers la compréhension des astres parents des LGRB<br>Gamma-ray bursts (GRBs) are brief bursts of high-energy electromagnetic radiation originating from space, formed in an ultra-relativistic jet following the aftermath of a newly born stellar mass black hole. A subclass of so-called long-duration GRBs (LGRBs, lasting typically a few tens of seconds) have been shown to be associated with the core-collapse of massive stars. Due to the short-lived nature of massive stars, LGRBs have been suggested as promising tracers of star formation up to the earliest epochs of the Universe. However, not all massive star core-collapses give rise to LGRBs as these are rare events, requiring particular conditions to form. In this thesis, we investigate a crucial ingredient for using LGRBs as tracers of star formation: the LGRB efficiency, defined as the fraction of core-collapses that form an LGRB. In the first part of the thesis, we present a statistical population model developed to reproduce three carefully selected observational constraints. This model allows us to constrain the intrinsic LGRB population and quantify the LGRB efficiency, showing that it increases with redshift. The second part of the thesis is devoted to identifying the factors affecting the LGRB efficiency by studying a complete, unbiased sample of LGRBs at 1 < z < 2. We study the environments in which LGRBs form by studying the properties of their host galaxies and comparing them with typical star-forming galaxies. We show that, as expected from theoretical considerations, metallicity is a key driving factor behind the LGRB efficiency. These results combined bring us one step closer to understanding the progenitors of LGRBs
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Chen, J. C., and 陳志清. "Theory of Constraints Applied to the Production and Marketing of the Switchgear in Taiwan－The case of N Company." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/95541850371461798611.
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碩士<br>國立交通大學<br>管理學院高階主管管理碩士學程<br>94<br>Switchgear is the requisite equipment of the electricity and control system so the supply and demand of the switchgear are closely linked to the growth of the using demand of the electricity system. The rapid and strong development of mainland China economy in recent years has caused absorbent effect, which led the domestic industry in Taiwan to the investing reduction. It is predictable that the switchgear demand of the domestic market in Taiwan will grow less. Besides, the switchgear export from Taiwan can’t be competed with the international major companies as well. Therefore, there will be a huge impact on domestic switchgear industry, which will make the competition among those switchgear manufactories more intensively. There are 115 companies of the switchgear manufacture in Taiwan. This case study uses a switchgear manufactory, so-called “N company”, as the example. N company, the leading switchgear manufactory in Taiwan, predicts the demand of the switchgear will less grow gradually in the future. To ensure the leading position in the manufacture, how to change the patterns of taking orders and producing products to lift the competitive ability will increase its revenue and profits.
To seek the strategies to improve, this research applies Theory of Constraints by Dr. Eliyahu M Goldratt to find out the core conflict. The main demands of the clients are quality, delivery time, price and service. However, the major six items of undesirable effects of N company’s can’t be satisfied with its clients’ demands, which imply the crises of the decreases of revenue and profits. Using the analysis of Theory of Constraints Evaporating Cloud, we can get the core conflict , the conflicts of the product manufacture standardized or not standardized from the clients’ demands. Then, draw out the strategy, “Manufacturing the products to meet the client’s demands and to maximize the company’s capacity.” Therefore, N company chooses the international excellent label to build up the technical collaboration and the business partner relationship to manufacture the standardized products, which can make the delivery time shortened, the products standardized by the international institutes, and the inventory built for the well-prepared service. Then, with instructions and promotion, clients will adopt the products.
Because the standards are less and the employees are more skillful, after the product standardization, the quality of the products can be guaranteed. Also, it can use the automatic equipments to manufacture for the production procedure, which will decrease the dependence on the employees and increase the efficiency of the production. To make annual purchasing agreements can dramatically shorten the operation time of the supply chain and decrease the excess of the capital to lower the cost. Not only to meet the clients’ demands on quality, delivery time, price and service but the standardization also lowers the cost the meanwhile and lifts the competitive ability to increase its revenue and profits. After the development of N company in its standardization, according to Theory of Constraints based on future, this research can suggest the study trends for the ongoing improvements in the future.
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Maesela, Lesedi Molefe. "Assessment of the production and marketing constraints of dairy goat and goat milk faced by rural household dairy-goat farmers in Sekhukhune District of Limpopo Province South Africa." Diss., 2017. http://hdl.handle.net/10500/23693.
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Beal, Colin McCartney. "Constraints on algal biofuel production." Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-05-2775.
Full textAbstract:
The aspiration for producing algal biofuel is motivated by the desire to replace conventional petroleum fuels, produce fuels domestically, and reduce greenhouse gas emissions. Although, in theory, algae have the potential to produce a large amount of petroleum fuel substitutes and capture carbon emissions, in practice, profitable algal biofuel production has proven quite challenging. This dissertation characterizes the production pathways for producing petroleum fuel substitutes from algae and evaluates constraints on algal biofuel production. Chapter 8 provides a summary of the entire dissertation.
The first chapter provides a framework for reporting the production of renewable diesel from algae in a consistent way by using data that are specific and by presenting information with relevant metrics. The second chapter presents a review of analytical tools (i.e., microscopy, spectroscopy, and chromatography) that can be used to analyze the structure and composition of intermediate products in an algal biofuel production pathway.
In chapters 3 through 6, the energy return on investment, water intensity, and financial return on investment are presented for three cases: 1) an Experimental Case in which data were measured during five batches of algal biocrude production with a combined processed volume of about 7600 L, 2) a hypothetical Reduced Case that assumes the same energy output as the Experimental Case, with reduced energy and material inputs, and 3) a Highly Productive Case that assumes higher energy outputs than the Experimental Case, with reduced energy and material inputs, similar to the Reduced Case.
For all three cases, the second-order energy return on investment was determined to be significantly less than 1, which means that all three cases are energy negative. The water intensity (consumption and withdrawal) for all cases was determined to be much greater than that of conventional petroleum fuels and biofuels produced from non-irrigated crops. The financial return on investment was also found to be significantly less than 1 for all cases, indicating production would be unprofitable. Additionally, it was determined that large-scale algal biofuel production would be constrained by the availability of critical energy and material inputs (e.g., nitrogen and carbon dioxide).
The final part of this dissertation presents a first-principles thermodynamic analysis that represents an initial attempt at characterizing the thermodynamic limits for algal biofuel production. In that analysis, the energy, entropy, and exergy is calculated for each intermediate product in the algal biofuel production pathway considered here.
Based on the results presented in this body of work, game-changing technology and biotechnology developments are needed for sustainable and profitable algal biofuel production.<br>text