This paper analyses and develops models for programmer participation and effort estimation in open source software projects. This has not yet been a centre of research, although any results would be of high importance for assessing the efficiency of this model and for various decision-makers. In this paper, a case study is used for hypotheses generation regarding manpower function and effort modeling, then a large data set retrieved from a project repository is used to test these hypotheses. The main results are that Norden-Rayleigh-based approaches need to be complemented to account for the addition of new features during the lifecycle to be usable in this context, and that programmer-participation based effort models show significantly less effort than those based on output metrics like lines-of-code. (author's abstract) / Series: Working Papers on Information Systems, Information Business and Operations

A migração de processos é importante em programas MPI por vários motivos, tais como permitir re-escalonamento de processos, balanceamento de cargas e tolerância a falhas. Independentemente do tipo do uso da migração, conhecer o custo imposto pela realização desta operação é um problema pertinente. Quando utiliza-se migração para tentar diminuir o tempo de execução de uma aplicação paralela, este custo passa a ser um ponto crítico. Existem algumas soluções para migração de processos em programas MPI disponíveis atualmente. No entanto, ainda não existe um estudo que quantifique o custo destas migrações. Nesse contexto, este trabalho apresenta um estudo para modelar e dimensionar o custo de migração de processos em programasMPI. Primeiramente, o trabalho identificou, analisou, avaliou e, quando necessário, adaptou as principais soluções disponíveis atualmente para migrar processos MPI. Com base nessas soluções, foram criados modelos de custo que poderão ser utilizado para estimar dinamicamente os custos de migração e auxiliar na tomada de decisão em algoritmos de escalonamento. Osmodelos criados foram utilizados para estimar os custos demigração emaplicações paralelas e o resultado foi comparado comos custos demigração reais. Nesta comparação, os valores previsto ficaram bastante próximos dos valores observados no experimento, demonstrando a qualidade das previsões dos modelos propostos. / Process migration is essential for MPI programs for different reasons, such as processes rescheduling, load balancing and fault tolerance. Knowing well the cost necessary for this operation is a pertinent problem, regardless of the type of migration use. Whenever migration is used for improving the performance of parallel applications, its cost becomes a deciding point. Nowadays, there are some solutions to process migration available for MPI programs. However, there is not a study that can quantify the migration cost and its impact on the execution of MPI programs. In this context, this work presents a study for modeling and dimensioning the process migration cost in MPI programs. First, we identified, analyzed, evaluated and, when needed, adapted the main solutions which are presently available to migrate MPI processes. Based in these solutions, we defined cost models. These models can be used to dynamically estimate the migration costs and to guide scheduling decisions. These models were used to predict the migration cost in parallel applications and the result was compared to observed migration costs. In this comparison, the predicted values were very similar to those observed in the experiment. This work still shows an evaluation about the impact of a migration in the execution of real parallel applications in order to verifying the viability of applying this approach to improve the performance.

A migração de processos é importante em programas MPI por vários motivos, tais como permitir re-escalonamento de processos, balanceamento de cargas e tolerância a falhas. Independentemente do tipo do uso da migração, conhecer o custo imposto pela realização desta operação é um problema pertinente. Quando utiliza-se migração para tentar diminuir o tempo de execução de uma aplicação paralela, este custo passa a ser um ponto crítico. Existem algumas soluções para migração de processos em programas MPI disponíveis atualmente. No entanto, ainda não existe um estudo que quantifique o custo destas migrações. Nesse contexto, este trabalho apresenta um estudo para modelar e dimensionar o custo de migração de processos em programasMPI. Primeiramente, o trabalho identificou, analisou, avaliou e, quando necessário, adaptou as principais soluções disponíveis atualmente para migrar processos MPI. Com base nessas soluções, foram criados modelos de custo que poderão ser utilizado para estimar dinamicamente os custos de migração e auxiliar na tomada de decisão em algoritmos de escalonamento. Osmodelos criados foram utilizados para estimar os custos demigração emaplicações paralelas e o resultado foi comparado comos custos demigração reais. Nesta comparação, os valores previsto ficaram bastante próximos dos valores observados no experimento, demonstrando a qualidade das previsões dos modelos propostos. / Process migration is essential for MPI programs for different reasons, such as processes rescheduling, load balancing and fault tolerance. Knowing well the cost necessary for this operation is a pertinent problem, regardless of the type of migration use. Whenever migration is used for improving the performance of parallel applications, its cost becomes a deciding point. Nowadays, there are some solutions to process migration available for MPI programs. However, there is not a study that can quantify the migration cost and its impact on the execution of MPI programs. In this context, this work presents a study for modeling and dimensioning the process migration cost in MPI programs. First, we identified, analyzed, evaluated and, when needed, adapted the main solutions which are presently available to migrate MPI processes. Based in these solutions, we defined cost models. These models can be used to dynamically estimate the migration costs and to guide scheduling decisions. These models were used to predict the migration cost in parallel applications and the result was compared to observed migration costs. In this comparison, the predicted values were very similar to those observed in the experiment. This work still shows an evaluation about the impact of a migration in the execution of real parallel applications in order to verifying the viability of applying this approach to improve the performance.

A migração de processos é importante em programas MPI por vários motivos, tais como permitir re-escalonamento de processos, balanceamento de cargas e tolerância a falhas. Independentemente do tipo do uso da migração, conhecer o custo imposto pela realização desta operação é um problema pertinente. Quando utiliza-se migração para tentar diminuir o tempo de execução de uma aplicação paralela, este custo passa a ser um ponto crítico. Existem algumas soluções para migração de processos em programas MPI disponíveis atualmente. No entanto, ainda não existe um estudo que quantifique o custo destas migrações. Nesse contexto, este trabalho apresenta um estudo para modelar e dimensionar o custo de migração de processos em programasMPI. Primeiramente, o trabalho identificou, analisou, avaliou e, quando necessário, adaptou as principais soluções disponíveis atualmente para migrar processos MPI. Com base nessas soluções, foram criados modelos de custo que poderão ser utilizado para estimar dinamicamente os custos de migração e auxiliar na tomada de decisão em algoritmos de escalonamento. Osmodelos criados foram utilizados para estimar os custos demigração emaplicações paralelas e o resultado foi comparado comos custos demigração reais. Nesta comparação, os valores previsto ficaram bastante próximos dos valores observados no experimento, demonstrando a qualidade das previsões dos modelos propostos. / Process migration is essential for MPI programs for different reasons, such as processes rescheduling, load balancing and fault tolerance. Knowing well the cost necessary for this operation is a pertinent problem, regardless of the type of migration use. Whenever migration is used for improving the performance of parallel applications, its cost becomes a deciding point. Nowadays, there are some solutions to process migration available for MPI programs. However, there is not a study that can quantify the migration cost and its impact on the execution of MPI programs. In this context, this work presents a study for modeling and dimensioning the process migration cost in MPI programs. First, we identified, analyzed, evaluated and, when needed, adapted the main solutions which are presently available to migrate MPI processes. Based in these solutions, we defined cost models. These models can be used to dynamically estimate the migration costs and to guide scheduling decisions. These models were used to predict the migration cost in parallel applications and the result was compared to observed migration costs. In this comparison, the predicted values were very similar to those observed in the experiment. This work still shows an evaluation about the impact of a migration in the execution of real parallel applications in order to verifying the viability of applying this approach to improve the performance.

The use of biofuels in the United States has increased dramatically in the last few years. The largest source of feedstock for ethanol to date has been corn. However, corn is also a vitally important food crop and is used commonly as feed for cattle and other livestock. To prevent further diversion of an important food crop to production of ethanol, there is great interest in developing commercial-scale technologies to make ethanol from non-food crops, or other suitable plant material. This is commonly referred to as biomass. A review is made of lignocellulosic sources being considered as feedstocks to produce ethanol. Current technologies for pretreatment and hydrolysis of the biomass material are examined and discussed. Production data and cost estimates are culled from the literature, and used to assist in development of mathematical models for evaluation of production ramp-up profiles, and cost estimation. These mathematical models are useful as a planning tool, and provide a methodology to estimate monthly production output and costs for labor, capital, operations and maintenance, feedstock, raw materials, and total cost. Existing credits for ethanol production are also considered and modeled. The production output in liters is modeled as a negative exponential growth curve, with a rate coefficient providing the ability to evaluate slower, or faster, growth in production output and its corresponding effect on monthly cost. The capital and labor costs per unit of product are determined by dividing the monthly debt service and labor costs by that month’s production value. The remaining cost components change at a constant rate in the simulation case studies. This methodology is used to calculate production levels and costs as a function of time for a 25 million gallon per year capacity cellulosic ethanol plant. The parameters of interest are calculated in MATLAB with a deterministic, continuous system simulation model. Simulation results for high, medium, and low cost case studies are included. Assumptions for the model and for each case study are included and some comparisons are made to cost estimates in the literature. iv While the cost per unit of product decreases and production output increases over time, some reasonable cost values are obtained by the end of the second year for both the low and medium cost case studies. By the end of Year 2, total costs for those case studies are $0.48 per liter and $0.88 per liter, respectively. These cost estimates are well within the reported range of values from the reviewed literature sources. Differing assumptions for calculations made by different sources make a direct cost comparison with the outputs of this modeling methodology extremely difficult. Proposals for reducing costs are introduced. Limitations and shortcomings of the research activity are discussed, along with recommendations for potential future work in improving the simulation model and model verification activities. In summary, the author was not able to find evidence—within the public domain—of any similar modeling and simulation methodology that uses a deterministic, continuous simulation model to evaluate production and costs as a function of time. This methodology is also unique in highlighting the important effect of production ramp-up on monthly costs for capital (debt service) and labor. The resultant simulation model can be used for planning purposes and provides an independent, unbiased estimate of cost as a function of time.

Investment in new technologies is considered by firms as a solution to improve their productivity, product and service quality and their competitive advantages in the global market. Unfortunately, not all technology adoption projects have met their intended objectives. The complexity of technology adoption along with little consideration of the long term cost of the technology, are among the factors that challenge companies while adopting a new technology. Companies often make new technology adoption decision without enough attention to the total cost of the technology over its lifecycle. Sometimes poor decision making while adopting a new technology can result in substantial recurring loss impacts. Therefore, estimating the total cost of the technology is an important step in justifying the technology adoption. Total Ownership Cost (TOC) is a wildly-accepted financial metric which can be applied to study the costs associated with the new technology throughout its lifecycle. TOC helps companies analyze not only the acquisition and procurement cost of the technology, but also other cost components occurring over the technology usage and service stage. The point is that, technology adoption cost estimation is a complex process involving consideration of various aspects such as the maintenance cost, technology upgrade cost and the cost related to the human-resource. Assessing the association between the technology characteristics (technology upgrades over its life cycle, compatibility with other systems, technology life span, etc) and the TOC encompasses a high degree of complexity. The complexity exists because there are many factors affecting the cost over time. Sometimes decisions made today can have long lasting impact on the system costs and there is a lag between the time the decision is taken and when outcomes occur. iv An original contribution of this dissertation is development of a System Dynamics (SD) model to estimate the TOC associated with the new technology adoption. The SD model creates casual linkage and relationships among various aspects of the technology adoption process and allows decision makers to explore the impact of their decisions on the total cost that the technology brings into the company. The SD model presented in this dissertation composes of seven sub-models including (1) technology implementation efforts, (2) workforce training, (3) technology-related workforce hiring process, (4) preventive and corrective maintenance process, (5) technology upgrade, (6) impact of technology on system performance and (7) total ownership cost sub model. A case study of Enterprise Resource Planning (ERP) system adoption has been used to show the application of the SD model. The results of the model show that maintenance, upgrade and workforce hiring costs are among the major cost components in the ERP adoption case study presented in Chapter 4. The simulation SD model developed in this dissertation supports trade-off analysis and provides a tool for technology scenarios evaluation. The SD model presented here can be extended to provide a basis for developing a decision support system for technology evaluation.

Product costing can be used to estimate potential future costs and revenues associated with a product. In the development of new products early cost estimates can be used to support decision making regarding which products are worth pursuing, and which production processes that are the most profitable. For a firm to make precise early cost estimates both technical and financial expertise is needed; however, in practice there is generally a gap between technology and cost. Process-Based Cost Modeling (PBCM) is a model developed to address this gap and generate costing estimates of higher precision. The model is especially developed for process production technologies. Although promising, PBCM is under researched and its applicability in new contexts are yet to be explored.  The purpose of this study was to explore the PBCM’s applicability in new context of process production. This was done through a case study at a multinational agricultural cooperative. The problematization presented by the Case Company was to make early cost estimation of the production process of a main product and its byproducts. Furthermore, the Case Company wanted to compare alternative production designs and use of different raw materials in the production process. To create a product costing model that fully captures the contextual depth of the problem both qualitative and quantitative data was gathered from internal documents, a series of interviews, and observation of one of the sub-processes.  The findings of the study resulted in development of a batch costing model, a hybrid between continuous operations and order costing systems. The batch costing proved to be dynamic and allowed comparison of different production and raw material alternatives. Furthermore, the PBCM methodology that resulted in the batch costing model was evident to give a deeper contextual understanding of the relationship between cost and production technology. For the Case Company, the outcome of the study highlighted key areas needing further investigation and process design features that lower operational costs. The results also provide recommendations how to increase the precision of the product costing models when more data are available. Finally, the academic outcome of the thesis provides trajectory in the further research on PBCM and gives new perspective on the use of batch costing in continuous operations. / Produktkalkylering kan användas för att uppskatta framtida kostnader och intäkter associerade med en produkt. Vid utveckling av nya produkter och produktionsprocess kan produktkalkylering således användas vid beslutsfattande i situationer där man ska välja vilka produkter som är värda att arbeta vidare med, och vid lönsamhetsberäkningar vid olika tillverkningsprocesser. För att företaget ska kunna göra precisa kostnadsuppskattningar behövs både teknisk och ekonomisk expertis. Detta överses dock ofta i praktiken, vilket leder till en klyfta mellan teknik och kostnad. Processbaserad kostnadsmodellering, eller Process-Based Cost Modeling (PBCM), är en metod som har tagits fram för att överkomma denna klyfta, framförallt inom processproduktion. Även om modellen är lovande så saknas forskning på området, därav behöver PBCM:s applicerbarhet prövas i nya kontexter. Syftet med denna studie var att undersöka PBCM:s applicerbarhet i en ny kontext inom processproduktion. Detta gjordes genom att genomföra en fallstudie på ett multinationellt lantbruksföretag som har verksamhet inom livsmedelproduktion. Fallföretags problematisering byggde på att de ville göra en tidig kostnadsbedömning på tillverkningsprocess som producerar en huvudprodukt och ett antal biprodukter. Tillverkningsprocessen är ännu inte utvecklad och företaget vill således jämföra produktionskostnader vid användning av olika råmaterial och tillverkningsalternativ. För att utveckla en lämplig produktkalkyl till företaget samlades både kvalitativa och kvantitativa data in genom interna dokument, en serie av intervjuer, samt genom observation av en av de underliggande tillverkningsprocesserna. Studien resulterade i en hybridkalkyl som använder sig av både process- och orderkalkylering. Hybridkalkylen visade sig lämplig både för företagets produktionsteknologi, men framförallt tillät jämförelse mellan olika tillverkningsalternativ. Metodiken hos PBCM visade sig även användbar för att förstå hur kostnaden påverkas av produktionsteknologin. För fallföretaget påvisade resultaten områden som behöver undersökas ytterligare. Det ges även rekommendationer hur hybridkalkylen kan finslipas när företaget har mer data tillgängligt. När det kommer till det akademiska bidraget, så ger rapporten riktning för fortsatta forskningen på PBCM och ger nya perspektiv på hur hybridkalkylering kan användas i processproduktion.

This dissertation is focused on studying transport behavior in vapor chambers at ultra-thin form factors so that their use as heat spreaders can be extended to applications with extreme space constraints. Both the steady-state and transient thermal transport behaviors of vapor chambers are studied. The steady-state section presents an experimental characterization technique, methodologies for the design of the vapor chamber wick structure, and a working fluid selection procedure. The transient section develops a low-cost, 3D, transient semi-analytical transport model, which is used to explore the transient thermal behavior of thin vapor chambers: 1) The key mechanisms governing the transient behavior are identified and experimentally validated; 2) the transient performance of a vapor chamber relative to a copper heat spreader of the same external dimensions is explored and key performance thresholds are identified; and 3) practices are developed for the design of vapor chambers under transient conditions. These analyses have been tailored to ultra-thin vapor chamber geometries, focusing on the application of heat spreading in mobile electronic devices. Compared to the conventional scenarios of use for vapor chambers, this application is uniquely characterized by compact spaces, low and transient heat input, and heat rejection via natural convection.

Humans have a profound impact on ecosystems, and land-use change constitutes a primary driving force in the loss of biodiversity. Habitat loss and fragmentation are key factors in this process by seriously impeding the habitat availability and movement of species, leading to a significant decrease in population viability. Landscape connectivity management able of crossing administrative and ecological spatial and temporal scales has been identified as one of the most important measures to counteract these negative impacts. The use of graph-theory and network-based landscape-ecological tools has become established as a promising way forward to address these issues. Despite urgent needs to adapt and implement such tools in planning, assessment and decision-making, surprisingly little attention has been paid to developing approaches for their effective practical application. This thesis presents the development of a toolbox with network-based, landscape-ecological methods and graph-theoretic indicators, which can be effectively implemented by practitioners within environmental assessment, physical planning and design, to analyze landscape connectivity. Recent advances in network analysis and landscape ecology are brought together and adapted for practical application, bridging the gap between science and practice. The use of participatory approaches was identified as key to successful development, and several workshops, meetings, interviews, as well as prototype testing of the developed software were conducted throughout the study. Input data and selection of species were based on the experience gained through seven real-world cases, commissioned by different governmental organizations within Stockholm County. The practitioners’ perspectives on effective practical application of the proposed toolbox were then assessed through an interview-study. The respondents anticipated improved communication with other actors in addition to being able to better assess critical ecological structures within the landscape. The toolbox was finally tested in a large-scale network analysis of impacts of the regional development plan (RUFS 2010), leading to important insights on the planning of connectivity in an urbanizing region. / <p>QC 20111125</p>

Conceptual cost estimates play a crucial role on initial project decisions although scope is not finalized and very limited design information is available during early project stages. At these stages, cost estimates are needed by the owner, contractor, designer or the lending organization for several purposes including / determination of feasibility of a project, financial evaluation of a number of alternative projects or establishment of an initial budget. Conceptual cost estimates are not expected to be precise, since project scope is not finalized and very limited design information is available during the pre-design stages of a project. However / a quick, inexpensive and reasonably accurate estimate is needed based on the available information. In this study, conceptual cost estimating models will be developed for urban railway systems using data of projects from Turkey. The accuracy of the models and advantages of the study will be discussed.