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A common practice in reliability studies is to model the failure process of systems with a single distribution. This thesis investigates this practice for modeling the failure distribution of systems subject to a finite number of independent failure mechanisms experiencing age acceleration. The models of systems during component age acceleration and the models of the residual lives of systems surviving component age acceleration are investigated. The fit of a single distribution to represent the failure time distribution of such systems is investigated for both modeling environments. More importantly, the assumption of time scale compression, and the resulting effect of parameter stability in the single Weibull and lognormal distribution models, is investigated for systems experiencing both differential component age acceleration and uniform component age acceleration. The analysis in this thesis shows that single distribution models are biased when modeling systems with non-identical components. Also, parameter stability in the single distribution models does not occur when the components experience differential age acceleration. The bias in the models leads systems with uniform age acceleration to experience parameter instability because of data dependency due to the bias. / Master of Science

This research presents a framework system dynamics (simulation) model that evaluates the effect of maintenance policies on system performance and life-cycle cost. The model highlights factors such as learning, aging and the technological upgrades that occur during the life-cycle of a system. The metrics used to measure the effectiveness of maintenance policies are the system life-cycle cost and cumulative breakdowns. In this research, a varying maintenance policy has been modeled using system dynamics methodology to determine the future performance of the system that is dependent upon its past performance when breakdowns occur randomly. The main objective of this modeling approach is to balance the cost of preventive maintenance actions with the opportunity losses due to system breakdowns. The approach used in this research primarily involves forecasting future breakdowns using an average of accumulated opportunity losses. This research effort was mainly aimed at developing a (framework) model to determine effective maintenance policy for a system and evaluating the effect on the life-cycle cost for various scenarios. This model could further form the basis of a decision support system for maintenance modeling. / Master of Science

Yes / Aneuploidy is usually deleterious in multicellular organisms but appears to be tolerated and potentially beneficial in unicellular organisms, including pathogens. Leishmania, a major protozoan parasite, is emerging as a new model for aneuploidy, since in vitro-cultivated strains are highly aneuploid, with interstrain diversity and intrastrain mosaicism. The alternation of two life stages in different environments (extracellular promastigotes and intracellular amastigotes) offers a unique opportunity to study the impact of environment on aneuploidy and gene expression. We sequenced the whole genomes and transcriptomes of Leishmania donovani strains throughout their adaptation to in vivo conditions mimicking natural vertebrate and invertebrate host environments. The nucleotide sequences were almost unchanged within a strain, in contrast to highly variable aneuploidy. Although high in promastigotes in vitro, aneuploidy dropped significantly in hamster amastigotes, in a progressive and strain-specific manner, accompanied by the emergence of new polysomies. After a passage through a sand fly, smaller yet consistent karyotype changes were detected. Changes in chromosome copy numbers were correlated with the corresponding transcript levels, but additional aneuploidy-independent regulation of gene expression was observed. This affected stage-specific gene expression, downregulation of the entire chromosome 31, and upregulation of gene arrays on chromosomes 5 and 8. Aneuploidy changes in Leishmania are probably adaptive and exploited to modulate the dosage and expression of specific genes; they are well tolerated, but additional mechanisms may exist to regulate the transcript levels of other genes located on aneuploid chromosomes. Our model should allow studies of the impact of aneuploidy on molecular adaptations and cellular fitness. / This study was supported by Belgian Science Policy Office (TRIT, P7/41), Flemish Fund for Scientific Research (G.0.B81.12), and Department of Economy, Science and Innovation in Flanders ITM-SOFIB (SINGLE project, to J.C.D.). G.D. and B.C. were supported by the Research Foundation—Flanders (FWO) (grants 12Q8115N and 11O1614N, respectively). V.S., J.M. and P.V. were supported by Czech Science Foundation (project no. 13-07500S) and Charles University (UNCE 204017/2012). J.R.V. was supported by research grants from the KU Leuven (SymBioSys [PFV/10/016]) and the Hercules Foundation (ZW11-14). M.S., M.B., and J.A.C. were supported by the Wellcome Trust through the core support for the Wellcome Trust Sanger Institute (grant no. 098051). G.B., P.P., and G.F.S. were supported by Institut Pasteur strategic fund for the LeiSHield project (to G.F.S.).

The study was conducted to establish what effect life cycle cost forecasting accuracy has on project valuations with special reference to a global mining organisation’s coal business unit in South Africa. The research stemmed from the fact that the organisation identified through its own research in 2009 that its capital projects rarely met the originally budgeted life cycle cost forecasts estimated during the project development stages. These forecasts were generally found to be underestimated. Overrunning of cost budgets in project management terms results in project failure. The study employed two main empirical research sections. The first section took a case study approach where past implemented project results were collated and analysed. The main aim was to determine how close to reality the original life cycle cost estimates were, and secondly how any variances to the originally budgeted costs impacted on the anticipated project value post implementation. Secondly, the study employed in-depth interviews with seven project specialists within the organisation that were also involved in the development stages of the investigated projects. The study concluded that life cycle cost forecasts are very important project business case inputs and that the necessary time and effort should go into developing them so as to ensure that they are as comprehensive and accurate as possible. The sensitivity analysis that was conducted revealed that a coal mining project business case is the second most sensitive to variations in life cycle costs after variations in commodity price. The results indicated that a 20% increase in life cycle costs can destroy an equivalent project value of up to 100%. Accurate life cycle cost forecasting is therefore essential in order to estimate to a certain degree of accuracy the value of a project which in turn will be used to inform capital investment decision making. / MBA, North-West University, Potchefstroom Campus, 2014

The study was conducted to establish what effect life cycle cost forecasting accuracy has on project valuations with special reference to a global mining organisation’s coal business unit in South Africa. The research stemmed from the fact that the organisation identified through its own research in 2009 that its capital projects rarely met the originally budgeted life cycle cost forecasts estimated during the project development stages. These forecasts were generally found to be underestimated. Overrunning of cost budgets in project management terms results in project failure. The study employed two main empirical research sections. The first section took a case study approach where past implemented project results were collated and analysed. The main aim was to determine how close to reality the original life cycle cost estimates were, and secondly how any variances to the originally budgeted costs impacted on the anticipated project value post implementation. Secondly, the study employed in-depth interviews with seven project specialists within the organisation that were also involved in the development stages of the investigated projects. The study concluded that life cycle cost forecasts are very important project business case inputs and that the necessary time and effort should go into developing them so as to ensure that they are as comprehensive and accurate as possible. The sensitivity analysis that was conducted revealed that a coal mining project business case is the second most sensitive to variations in life cycle costs after variations in commodity price. The results indicated that a 20% increase in life cycle costs can destroy an equivalent project value of up to 100%. Accurate life cycle cost forecasting is therefore essential in order to estimate to a certain degree of accuracy the value of a project which in turn will be used to inform capital investment decision making. / MBA, North-West University, Potchefstroom Campus, 2014

Innovation and technological change is the major factor of production, renewal, and competitiveness of firms and nations in the contemporary “knowledge economy”. The overall purpose of this dissertation is to investigate the innovative behavior of firms in various sectors and regions. In particular, I have analyzed the determinants (driving forces) of firms’ innovation on the one hand (in paper 1 and 2), and the effect of firms’ innovation on the other hand (in paper 3 and 4). In addition, a central concern in this dissertation is that context, in which firms operate and innovate, matters for innovation. I take into account several contexts in the analyses of both the determinants and effects of innovation. These contexts are: the regions in which firms are located, the dynamics of industries, and the dynamics of cluster in which firms belong to. This dissertation consists of four separate papers plus an introductory chapter. Each paper can be read independently, but all of them deal with either determinants or effects of the innovation of firms. The first paper analyzes the effect of various firm-specific determinants on firms’ innovation output. It also considers the stages of the Industry Life Cycle (ILC) as a context in which firms operate and innovate. Using the Community Innovation Survey data for manufacturing and service sectors in Sweden during 2002-2004, I find that the importance of various determinants of firms’ innovation depends on the stages of the ILC in which they operate. The second paper is again investigates the determinants of innovation, but this time incorporates another context that affect the innovation, i.e. the regions that firms belong to. Using the patent applications data as a measure of innovation in all functional regions in Sweden during 2002-2007, we find that both the internal knowledge generated within the region and the inflow of external knowledge matter for innovation of firms located in the regions. Moreover, the extent of related variety of knowledge in the region has the superior role to promote innovation. The third paper examines the effect of a firm’s innovation output on firm’s performance. Export behavior of firms is chosen as a performance indicator. Particular attention is devoted to distinguishing between innovation input and innovation output and to isolate their effects on export behavior of firms. Using two waves of Swedish Community Innovation Survey data during 2002-2006 merged with registered firm-level data, I find that what really matters for enhancing the export behavior of firms is the innovation output of firms, rather than the innovation input (mere efforts in investing in innovation activities). The fourth paper also analyzes the effect of innovation on performance measures but this time incorporates another context, i.e. the life cycle of the regional cluster that firms belong to. This paper delves into a particular cluster, i.e. Linköping ICT cluster. Using data collected through interviews during 2009 and 2012 on key cluster actors, we find that innovation is among the factors that are always highly important at any given stage of the cluster’s evolution, however, it has slightly greater importance during the “growing” stage.

A Avaliação do Ciclo de Vida (ACV) é uma ferramenta da gestão ambiental que identifica aspectos ambientais e avalia os impactos ambientais de um produto ao longo de todo o seu ciclo de vida. O ciclo de vida considera todas as atividades que vão desde a extração e processamento das matérias-primas, manufatura, transporte, distribuição, uso, reuso, manutenção e disposição final. Através da ACV são obtidas todas as entradas de massa e energia e as respectivas saídas na forma de emissões atmosféricas, efluentes líquidos e resíduos sólidos para cada atividade que compõe o ciclo de vida do produto estudado. No desenvolvimento da ACV, durante a fase de coleta de dados existe uma enorme quantidade de informações que necessita ser coletada. Para sanar essa dificuldade, vêm sendo desenvolvidos bancos de dados de insumos de grande importância os quais possuem características regionais, tornando o estudo mais completo e confiável. A utilização de bancos de dados tem caráter apenas regional, visto que as condições técnicas e ambientais podem variar de uma região para outra. Dependendo da região, a utilização de bancos de dados internacionais tende a distorcer os resultados dos estudos de ACV, conduzindo a resultados não adequados, os quais não representam a realidade da região em estudo. Neste contexto, o Grupo de Prevenção da Poluição do Departamento de Engenharia Química da Escola Politécnica da USP tem desenvolvido estudos que visam à obtenção de Inventários do Ciclo de Vida (ICVs) para auxiliar na construção de um banco de dados brasileiro. O presente estudo, inserido nessa linha de pesquisa, visa à construção do inventário do ciclo de vida do biodiesel etílico do óleo de girassol produzido no Brasil. O biodiesel é um combustível renovável constituído de uma mistura de monoalquilésteres de ácidos graxos de cadeia longa, derivados de óleos vegetais, gorduras animais ou óleos residuais. Neste estudo, definiu-se o sistema de produto para o biodiesel, o qual dividiu-se em subsistemas para facilitar a coleta de dados. Os dados coletados para cada um dos subsistemas foram predominantemente secundários, isto é, obtidos de publicações científicas e bases de dados estrangeiras. No entanto, os dados secundários foram adaptados à realidade brasileira, por meio de informações e considerações que consideraram as condições tecnológicas e de mercado existentes no Brasil. Como resultado verificou-se que 8 dentre todas as etapas do ciclo de vida do biodiesel, a produção dos grãos de girassol é a que demanda mais recursos materiais e energéticos e que provoca a maior quantidade de emissões para o meio ambiente. Deste modo, na produção do biodiesel deve ser dada atenção especial para a produção da oleaginosa, buscando soluções quanto ao seu alto consumo de recursos e emissões para o meio ambiente. / The Life Cycle Assessment (LCA) is a tool of the environmental management which identifies environmental aspects and evaluates environmental impacts of products during its whole life cycle. The life cycle considers all the activities since the extraction and manufacture of the raw materials, transport, distribuction, use, reuse, maintenance and final disposal. Through the LCA are obtained all the inputs of mass and energy and the respective outputs of atmospheric emissions, liquid effluents and solid wastes for every activity of the product life cycle studied. In the development of the LCA, during the phase of data collection there is a vast quantity of information to be collected. To avoid this difficulty, have been in development databases of important inputs, who has regional characteristics, becoming the study more complete and reliable. The database utilization has only a regional character, since the technical and environmental conditions can change in different regions. Depending of the region, the utilization of international database tends to distort the results of an LCA study, leading non adequate results, which don´t represent the reality of the region in study. In this context, de Pollution Prevention Group (GP2) of the Chemical Engineering Department of Polytechnic School of USP have developed studies that aims to obtain Life Cycle Inventories (LCI) to assist the construction of a Brazilian database. The present study is inserted in such line of research and aims to the construction of the sunflower oil ethylic biodiesel LCI made in Brazil. The biodiesel is a renewable fuel, it is constituted of a mix of mono alkyl esters of long chain fatty acids derived of vegetable oils, animal fats or residual oils. In this study was defined the product system to biodiesel, which was divided in subsystems to assist the data collection. The data were collected for each one of the subsystems were in the majority secondary, obtained of scientific publications and foreign databases. However, the secondary data were adapted to the brazilian reality through informations and considerations that take into account the actual brazilian technological and market conditions. As a result it was verified that among all the steps of the biodiesel life cycle, the agricultural production of the sunflower is that one who demands more energetic and materials inputs and is responsible for the majority of the emissions to the environment. In this way, in the biodiesel production should 10 be given special attention to the agricultural production of the oilseed, searching for solutions to its high consumption of inputs and environmental emissions.