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1
BALDI, GIORGIO. "IDENTIFICATION AND CHARACTERIZATION OF STRESSED REPLICATION FORK INTERMEDIATES." Doctoral thesis, Università degli Studi di Milano, 2019. http://hdl.handle.net/2434/609359.
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The DNA replication machinery encounters a number of obstacles while duplicating the genome, which put the replicative apparatus under stress. Cells have developed a number of mechanisms to overcome replication stress sources. However, in the presence of chronic stress, or after loss of key factors that help to deal with this stress, a range of deleterious events can occur. One of the main pathways implicated in DNA damage sensing and response is DNA damage checkpoint. When DNA replication fork progression is blocked, checkpoint activation ensures structural stability of the replisome components avoiding fork collapse and promoting, when possible, fast resumption of DNA replication. One of the hallmarks of replication stress is the accumulation single-stranded DNA at the replication forks. Here we used Atomic Force microscopy (AFM) and Electron Microscopy (EM)-based approaches to provide a detailed characterization of DNA lesions arising in the presence of replication stress imposed by interference with DNA polymerase activity in Xenopus laevis egg extract. We identified a number of intermediates induced by DNA polymerase inhibition, including replication forks containing ssDNA gaps and reversed forks (RVFs). Importantly, we directly correlated the presence and the length of ssDNA gaps at the replication fork junctions with the onset RVFs. Significantly, we identified one possible source of ssDNA gap accumulation at forks by showing that homologous recombination protein Rad51 is required for optimal function of Polymerase-alpha at stressed replication forks. To fulfill this function, Rad5/Pol-alpha interaction is likely to be important for stalled fork resumption. We also provided evidence that replication fork intermediates with persistent ssDNA gaps are converted into RVFs by Smarcal1 translocase, showing that this enzyme is among the most important fork remodelers that can trigger fork reversal upon fork stalling. We also showed that RVFs can trigger extensive Mre11 dependent DNA degradation upon replication stress in the absence of functional Rad51. Finally, we provided mechanistic insights into checkpoint regulation of RVFs levels through ATR, Smarcal1 and Rad51 regulation. Overall this provides structural and molecular insights into the metabolisms of replication forks under stressful conditions.
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Hallberg, Jonatan, and Joel Winninge. "In-plant reverse logistics: The reversed flow of steel scrap for reuse at Sandvik Materials Technology." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119981.
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Syftet med denna studie är att kartlägga flödet av returstål inom SMT för att identifiera eventuella problem samt, om så är fallet, presentera förbättringsförslag för att åtgärda dessa. Kartläggningen visade att ett fåtal produktionsenheter står för majoriteten av returstålet som uppstår inom SMT samt att det överlag föreligger brister i sorteringen. Felsorteringen medför kostnader i form av ökad hantering, minskat materialvärde samt problem vid smältningsprocessen i Stålverket. En av anledningarna till felsorteringen är avsaknaden av återkoppling i form av kostnader och sorteringskvalitet till varje produktionsenhet. Det har via kartläggningen framkommit att transportkostnaderna är låga relativt materialvärdet. Därför är det av vikt att returstålet transporteras till Råvarugården snabbt. Resultatet av denna studie är att returstålsflödet skulle bli effektivare genom förbättrad sortering snarare än genom minskade transportkostnader.
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Buss, Amanda Sória. "Proposta de embalagem para logística reversa em projeto de Design para o Território." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/85034.
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A logística reversa de embalagem (LRE) e o design orientado ao território (DT) são abordagens com ênfases diferentes, mas que possuem características que se complementam. A embalagem, por exemplo, surge como uma estratégia com o potencial de comunicação do território e de sustentabilidade ambiental, premissas do DT, através da logística reversa. Este trabalho tem como principal objetivo propor diretrizes e práticas para integração entre essas duas abordagens, LRE e DT. Utilizou-se como unidade de análise um processo de produção orgânica. O método adotado foi a pesquisa-ação, contendo atividades como: (i) revisão de literatura sistematizada para identificação e análise de conceitos, diretrizes, objetivos e ações que permitisse a integração entre a LRE e o DT; (ii) identificação de oportunidades de LRE no contexto do DT a partir do mapeamento de um processo e da sugestão de ferramentas como o blueprint, o Service Failure Mode and Effect Analysis (SFMEA) e a matriz SWOT; (iii) testar as diretrizes de integração propostas em um projeto de embalagens. Dentre os principais resultados do trabalho estão a apresentação de um conjunto de diretrizes norteadoras de LRE em projetos de DT; um diagnóstico de oportunidade de LRE em um projeto de DT, no caso o dos produtores de hortaliças orgânicas; proposição de uma ferramenta para avaliação da integração entre as abordagens e o grau de formalismo presente no planejamento e na gestão da LRE, denominada RADAR DT-LRE; o replanejamento do sistema logístico e o projeto de embalagens; e a aplicação da ferramenta RADAR DT-LRE. Constatou-se que as diretrizes, objetivos e ações integradas entre LRE e DT nortearam de forma satisfatória o sistema de LRE e o projeto das embalagens no caso investigado, apresentando melhorias em relação seu ao estado inicial. As diretrizes com destaque foram: proteção e perpetuação da identidade e do patrimônio, desenvolvimento econômico, redução do impacto ambiental; melhoria da imagem da empresa/negócio e, em menor grau, infraestrutura de suporte ao sistema de logística reversa de embalagens.The packaging reverse logistics (PRL) and the territorial design (TD) are approaches with different emphases, but that have characteristics that complement each other. The packaging, for example, appears as a strategy with the potential for territory communication and environmental sustainability - assumptions of TD - through reverse logistics. The main of this work is to propose guidelines and practices for integration between the two approaches, PRL and TD. A process of organic production was used as the analysis unit. The method adopted was the action research, containing activities such as: (i) systematic literature review to identify and analyze concepts, guidelines, objectives and actions that allow integration between the PRL and TD; (ii) identification of opportunities for PRL in the context of TD, from a process mapping and suggestion of tools such as blueprint, Service Failure Mode and Effect Analysis (SFMEA) SWOT matrix; and (iii) testing the integration guidelines proposed in a packaging project. The main results of the work are: presenting a set of guidelines for PRL in TD projects; a diagnosis of a opportunity of PRL in a TD project; proposal of a tool to evaluate the level of integration between the two approaches and the degree of formality present in the planning and in the management of PRL, called Radar TD-PRL; redesign of the logistics system and packaging design, and implementation of the tool RADAR TD-PRL. It was found that the guidelines, objectives and integrated actions between PRL and TD guided satisfactorily the PRL system and the packaging design in the investigated case, showing improvements compared to its initial state. The featured guidelines are: protection and perpetuation of identity and heritage, economic development, reduced environmental impact, improving the company's image / business, and, to a lesser extent, infrastructure support system for PRL.
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McAdam, Ian. "Connectionist models for reverse engineering." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=67543.
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Design recovery, a part of the reverse engineering process of a program, must supply a programmer with all the information they need to fully understand a program or a system. In this thesis, a connectionist method is proposed for analyzing the informal information (comments and mnemonics) in a program that can be used for design recovery in conjunction with more traditional approaches. A connectionist model was chosen because of its properties of being robust (capable of tolerating noisy inputs), its associative memory ability (capable of retrieving a concept given only the context of the original input word), and its generalization ability (learn conceptually relevant micro-features of the domain). The proposed approach uses a combination of top down domain analysis (the creation of a concept hierarchy by a domain expert, to be used in the formation of the training set) and a bottom up approach (the analysis of the informal information using the network).
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Pimenta, Aline de Barros. "Os agentes ambientais e a logística reversa dos resíduos sólidos urbanos na cidade de Juiz de Fora - MG." Universidade Federal de Juiz de Fora, 2012. https://repositorio.ufjf.br/jspui/handle/ufjf/1918.
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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Em função da geração crescente e diversificada de Resíduos Sólidos Urbanos e da implantação de um sistema de gestão inadequado, configura-se o agravamento de problemas ambientais, econômicos e sociais, relacionados tanto à saúde pública, quanto à contaminação do solo e da água. Diante deste contexto urbano, mundialmente reproduzido, apresenta-se como objetivo específico evidenciar a atividade logística reversa informal, realizada pelos catadores, e a sua capacidade de ampliar as possibilidades produtivas da tecnologia reversa e potencializar a redução, reutilização e reciclagem energética e material dos resíduos sólidos produzidos cotidianamente. A fim de avaliar a relação entre os trabalhadores de rua (catadores), o ambiente de trabalho e a qualidade de vida que caracteriza seus hábitos e atuações na cidade de Juiz de Fora, Minas Gerais, foram analisados dados aferidos em 2008 e reiterados em 2010 e 2011, com base em referencial teórico multidisciplinar com o propósito de viabilizar uma análise apurada da realidade da gestão municipal de resíduos sólidos em comparação à realidade nacional. A busca por uma maior eficiência das políticas de gestão dos resíduos sólidos e da integração deste sistema está diretamente relacionada à conscientização de seus geradores e o comprometimento dos diversos setores, públicos e privados. Com a análise do potencial ambiental, econômico e social da redução, reutilização e reciclagem, energética e material, dos resíduos sólidos gerados e coletados na cidade, foi possível inferir que a gestão adequada de resíduos associa-se à maior sustentabilidade das operações de logística reversa e reinserção de bens e materiais ao ciclo produtivo.
Due to the growing and diverse generation of urban solid waste and the establishment of an inadequate management system, the environmental, economic and social problems, all related to the public health and the contamination of soil and water, have gotten worse. In the face of this urban context, reproduced worldwide, it is presented as a specific objective to evidence the reverse logistics informal activity, conducted by the garbage collectors, and its ability to expand the productive possibilities of the reverse technology and enhance the energetic and material reduction, reuse and recycling of solid waste produced daily. In order to evaluate the relationship between street workers (garbage collectors), the work environment and the quality of life that characterizes their habits and actions in the city of Juiz de Fora, Minas Gerais, were analyzed measured data in 2008 and repeated in 2010 and 2011, based on a multidisciplinary theoretical reference with the aim of enabling a detailed analysis of the reality of the municipal management of solid waste in comparison to the national reality. The search for a greater efficiency of management policies of solid waste and the integration of this system is directly related to the awareness of their generators and the commitment of several sectors, public and private. By analyzing the environmental, economic and social potential of the reduction, reuse and recycling, energetic and material, of solid waste generated and collected in the city, we could infer that the proper management of waste has been associated to a greater sustainability of the reverse logistics operations and reintegration of goods and materials to the production cycle.
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Lima, Daniel Carneiro de. "Analysis of market forces and state in the formation of reverse chains of steel containers for beverages and lubricating oil in the textile industry." Universidade Federal do CearÃ, 2007. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=3647.
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nÃo hÃThis study analyzes the market and governmental forces informing the recycling policies of companies in the beverage can industry and the textile lubricant industry in CearÃ. The two industries were chosen for a comparative study of environmental strategies due to differences in the specific environmental regulation to which they are subjected. Companies in these sectors are adopting more responsible environmental protection policies as part of their national and international competitive strategies, since consumers and investors are increasingly recognizing the relation between industrial performance and environmental quality. Likewise, regulation is grower stricter regarding accountability for environmental damage. The main stakeholder influences affecting company policy-making were analyzed qualitatively using the model of institutional pressures proposed by Delmas (2004), according to which companies respond to the demands of the market, regulation and other stakeholders in order to increase their competitive advantage. The companies were also analyzed with regard to their environmental strategies and their understanding of and reaction to external pressures in view of their history of environmental performance, competitive position and organizational structure. The findings for the two industries compared in the study were organized according the model of institutional pressures, relating adopted environmental practices to external pressures and company profile. Environmental practices were evaluated with the help of indicators reflecting the quality of environmental management and its insertion into the overall business system, including general management, human resources, purchasing department, legal department, production, operation and marketing. The market â informed by international environmental standards â was found to be the strongest influence on company recycling policies in the beverage can industry. In the case of textile lubricants, these policies were most often determined by the international market and national regulations.
O trabalho apresenta uma anÃlise das forÃas de mercados e de Estado que agem sobre a formaÃÃo das cadeias reversas das embalagens de aÃo para bebidas e do Ãleo lubrificante utilizado pela indÃstria tÃxtil. A escolha desses dois setores teve como objetivo a realizaÃÃo de um estudo comparativo da conduta ambiental e estratÃgica das empresas cearenses em um ambiente onde ocorre regulamentaÃÃo especÃfica, como à o caso do Ãleo lubrificante, e onde nÃo existe uma regulamentaÃÃo especÃfica, que caracteriza a cadeia das embalagens de aÃo para bebida. Destaca-se tambÃm o fato de as empresas desses setores adotarem a proteÃÃo ambiental como parte de suas estratÃgias competitivas nacionais e internacionais, pois, tanto os consumidores como os investidores, estÃo comeÃando a ver com maior clareza as relaÃÃes entre o desempenho comercial e a qualidade ambiental. AlÃm das exigÃncias dos clientes, ressalta-se o fato de as legislaÃÃes terem se tornado mais rigorosas quanto à responsabilidade por danos ambientais. Mediante de uma anÃlise qualitativa, foram avaliadas as principais influÃncias exercidas pelas partes interessadas, segundo o Modelo das PressÃes Institucionais, proposto por Delmas (2004). Com base neste modelo, a empresa responde Ãs exigÃncias dos mercados, da legislaÃÃo e das demais partes interessadas, com o objetivo de obter vantagem competitiva, alÃm de se averiguar o comportamento ambiental das empresas diante da posiÃÃo estratÃgica que ocupam e a maneira como essas percebem e reagem Ãs pressÃes em funÃÃo de fatores especÃficos, tais como: o histÃrico de desempenho ambiental, a posiÃÃo competitiva das empresas-matrizes e a estrutura organizacional das organizaÃÃes. As tÃxteis e as integrantes da cadeia das embalagens de aÃo para bebida no Cearà tiveram os seus resultados organizados segundo o modelo das pressÃes institucionais, que relaciona a adoÃÃo de prÃticas ambientais em relaÃÃo Ãs pressÃes sofridas e de acordo com as caracterÃsticas das empresas. Avaliou-se tambÃm a conduta ambiental mediante de um conjunto de indicadores que refletem a qualidade do gerenciamento ambiental ao longo do sistema de negÃcios, incluindo administraÃÃo geral, recursos humanos, compras, jurÃdico, produÃÃo e operaÃÃo e marketing. A pesquisa constatou que, no setor das embalagens de aÃo para bebidas, o mercado, influenciado por padrÃes internacionais de conduta ambiental, à o que exerce maior influÃncia sobre as empresas para a formaÃÃo da cadeia reversa. Jà na cadeia reversa do Ãleo lubrificante na indÃstria tÃxtil, constatou-se que os mercados internacionais e a legislaÃÃo nacional sÃo os que exercem maiores influÃncias para a formaÃÃo dessas cadeias reversas.
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Liu, Xiaodong. "Abstraction : a notion for reverse engineering." Thesis, De Montfort University, 1999. http://hdl.handle.net/2086/4214.
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Sit, Eric N. 1977. "Reverse HTTP tunneling for firewall traversal." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/9086.
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Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.Includes bibliographical references (leaf 104).
This thesis describes a reverse hypertext tunneling protocol that allows a web browser from outside a firewall to access a web server inside a firewall. Reverse HTTP utilizes pre-existing proxy services to create a transparent and scalable method to tunnel through a firewall. Reverse HTTP provides an excellent solution to the problem of providing controlled access to firewall protected resources. This is because unlike traditional firewall traversal methods, reverse HTTP is completely software based and requires no changes to the existing firewall configuration. Reverse HTTP works because it tunnels traffic in a form which a web proxy server on the firewall allows to pass. A Java software implementation has been developed and tested to demonstrate the usefulness and efficacy of the reverse HTTP protocol. This experimental implementation proves that a portable, scalable solution can be developed with comparable performance characteristics to a normal web proxy. Although the implementation can be used to view protected web sites, it does not compromise the overall network security.
by Eric N. Sit.
S.B.and M.Eng.
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Hughes, Nina(Nina Yuchen). "Reverse logistics supply chain process modeling and simulation." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122581.
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Thesis: M.B.A., Massachusetts Institute of Technology, Sloan School of Management, 2019, In conjunction with the Leaders for Global Operations Program at MITThesis: S.M., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2019, In conjunction with the Leaders for Global Operations Program at MIT
Cataloged from PDF version of thesis.
Includes bibliographical references (page 67).
As consumer preferences shift towards online shopping and utilizing their homes as fitting rooms, traditional brick and mortar retailers are faced with the challenge to adapt. Many retailers are experiencing a growing number of returned merchandize, many of which cannot be easily resold to consumers due to various supply chain challenges. This thesis explores the opportunities to improve the consumer returns process and presents methods for modeling the supply chain process for reverse logistics in the retail industry derived from case studies. The model then allows for hypothesis testing. By changing parameters in the model, this thesis further explores the scenarios in which the supply chain process may be improved to increase margin and decrease cost. The primary recommendations include specific modifications to the current reverse supply chain flow, enabling new channels that improve speed and margin, as well as developing the decision tool further for better accuracy and integration into the supply chain.
by Nina Hughes.
M.B.A.
S.M.
M.B.A. Massachusetts Institute of Technology, Sloan School of Management
S.M. Massachusetts Institute of Technology, Department of Civil and Environmental Engineering
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Boyle, Casey Alex. "Process enablers for successful reverse engineering inside large organizations." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/126949.
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Thesis: M.B.A., Massachusetts Institute of Technology, Sloan School of Management, in conjunction with the Leaders for Global Operations Program at MIT, May, 2020Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, in conjunction with the Leaders for Global Operations Program at MIT, May, 2020
"May 2020." Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 131-135).
Reverse engineering has the potential to be a strategic advantage for many engineering companies. As companies continuously look for new ways to improve their business and technical expertise, reverse engineering facilitates detailed knowledge capture for many possible applications. These applications open new channels of revenue, create more options in the market, and drive value to customers. Although reverse engineering is nothing new to industry and has been actively researched, this thesis seeks to understand the key enablers that promote successful reverse engineering at scale in a modern corporation. Given that many large firms are set up with the forward engineering process in mind, what are the differentiated characteristics of an effective reverse engineering organization? By treating reverse engineering as a system of interconnected dependent events, an organization can be shaped to build a workflow with the necessary linkages for successful execution and scaling.
This "pull" more than "push" process that establishes clear communication between functions is key to preventing rework, shortening flow time, and increasing quality. Reverse engineering, like traditional forward engineering, must be organized as an integrated multifunctional process with organized information sharing, compromise, and iteration. Additionally, the teardown process itself is a central piece of the puzzle for successful reverse engineering. This is due to the multiple strategic linkages associated and interconnectedness required by key stakeholders for understanding the investigated component. A teardown is defined as an observant disassembly of a component for information gain. This thesis focuses more deeply into the teardown process. By showcasing challenges that lead to common errors, teardown process recommendations are made for a more efficient way to reverse engineer.
A lack of early stakeholder engagement prior to teardown frequently leads to inefficient knowledge sharing. More active stakeholder participation is recommended to improve the overall quality of teardown reports and serve as an additional opportunity to discover a component's hidden complexities. It is also recommended that formal design tools, such as functional analysis, be utilized for truly understanding a component's physical behavior. Implementing these recommendations and tools will increase the efficiency and output quality of reverse engineering teams, reducing rework.
by Casey Alex Boyle.
M.B.A.
S.M.
M.B.A. Massachusetts Institute of Technology, Sloan School of Management
S.M. Massachusetts Institute of Technology, Department of Mechanical Engineering
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Akgul, Tankut. "Assembly Instruction Level Reverse Execution for Debugging." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5249.
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Reverse execution can be defined as a method which recovers the states that a program attains during its execution. Therefore, reverse execution eliminates the need for repetitive program restarts every time a bug location is missed. This potentially shortens debug time considerably.
This thesis presents a new approach which, for the first time ever (to the best of the author's knowledge), achieves reverse execution at the assembly instruction level on general purpose processors via execution of a reverse program. A reverse program almost always regenerates destroyed states rather than restoring them from a record. Furthermore, a reverse program provides assembly instruction by assembly instruction execution in the backward direction. This significantly reduces state saving and thus decreases the associated memory and time costs of reverse execution support.
Furthermore, this thesis presents a new dynamic slicing algorithm that is built on top of assembly instruction level reverse execution. Dynamic slicing is a technique which isolates the code parts that influence an erroneous variable at a program point. The algorithm presented in this thesis achieves dynamic slicing via execution of a reduced reverse program. A reduced reverse program is obtained from a full reverse program by omitting the instructions that recover states irrelevant to the dynamic slice under consideration. This provides a reverse execution capability along a designated dynamic slice only. The use of a reduced reverse program for dynamic slicing removes the need for runtime execution trajectories.
The methodology of this thesis has been implemented on a PowerPC processor with a custom made debugger. As compared to previous work, all of which heavily use state saving techniques, the experimental results show up to 2206X reduction in runtime memory usage, up to 403X reduction in forward execution time overhead and up to 2.32X reduction in forward execution time for the tested benchmarks. Measurements on the selected benchmarks also indicate that the dynamic slicing method presented in this thesis can achieve up to six orders of magnitude (1,928,500X) speedups in reverse execution along the dynamic slice as compared to full-scale reverse execution.
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Hong, I.-Hsuan Ethan. "Decentralized Decision-making for Reverse Production Systems." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/14099.
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Reverse production systems are often comprised of several tiers with independent members competing at each tier. This research develops and designs a decision-making process for decentralized reverse production systems where each participant in the network determines its decisions in a self-interested way.
This dissertation includes three major parts. The first part develops a prototype model for a decentralized reverse production system with two tiers, collectors and processors, focusing on the coordination of transactions of recycled items between these two tiers. The collectors determine the individual material flow allocation mechanisms, based on predictions of the range of prices from the processors, that relate the flow amount to the overall vector of acquisition prices that will be offered by the processors to all the collectors. The processors compete for the flow from the collectors and reach an equilibrium state where no entity is willing to change its decisions.
In the second part, we extend the prototype model for a general multi-tiered recycling network comprised of the upstream boundary tier, several intermediate tiers, and the downstream boundary tier where each of the tiers has multiple independent entities. Recycled items flow from the top tier to the downstream tier, but acquisition prices are set from the downstream tier back to the upstream tier.
Finally the third part provides a comparison of centralized and decentralized models for reverse production systems and addresses several numerical insights of different system subsidy schemes.
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Meuli, Christian. "Reverse assays for high-thorughput multiplexd screening." Thesis, KTH, Skolan för bioteknologi (BIO), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149452.
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Radkevitch, Ulad. "Online reverse auctions for procurement of services /." Rotterdam : Erasmus Research Institute of Management, 2008. http://hdl.handle.net/1765/13497.
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Marklund, Sarah. "Reverse Stress Test Optimization : A study on how to optimize an algorithm for reverse stress testing." Thesis, Umeå universitet, Institutionen för fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-149178.
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In this thesis we investigate how to optimize an algorithm that determines a scenario multiplier for a reverse stress test with a method where predefined scenarios are scaled. The scenarios are composed by different risk factors that represents market events. A reverse stress test is used for risk estimation and explains for what market condition a given portfolio will lose a particular amount. In this study we consider a reverse stress test where the goal is to find for what scenario a clearing house become insolvent, that is when the clearing house's loss is equal to its resource pool. The goal with this work is to find a more efficient algorithm than the current bisection algorithm for finding the scenario multiplier in the reverse stress test. The algorithms that were examined were one bracketing algorithm (the false-position algorithm) and two iterative algorithms (the Newton-Raphson and Halley's algorithms), which were implemented in MATLAB. A comparative study was made where the efficiency of the optimized algorithms were compared with the bisection algorithm. The algorithms were evaluated by comparing the running times and number of iterations needed to find the scenario multiplier in the reverse stress test. Other optimization strategies that were investigated were to reduce the number of scenarios in the predefined scenario matrix to decrease the running time and determine an appropriate initial multiplier to use in the iterative algorithms. The reduction of scenarios consisted of removing the scenarios that were multiples of other scenarios by comparing the risk factors in each scenario. We used Taylor approximation to simplify the loss function and thereby approximate an initial multiplier, which would reduce the manually input from the user. Furthermore, we investigated the running times and number of iterations needed to find the scenario multiplier when several initial multipliers were used in the iterative algorithms to increase the chance of finding a solution. The result shows that both the Newton-Raphson algorithm and Halley's algorithm are more efficient and need less iterations to find the scenario multiplier than the current bisection algorithm. Halley's algorithm is the most efficient, which is on average 200-470% faster than the current algorithm depending on how many initial multipliers that are used (one, two or three), while the Newton-Raphson algorithm is on average 150-300% faster than the current algorithm. Furthermore, the result shows that the false-position algorithm is not efficient for this aim. The result from the reduction of scenarios shows that scenarios could be removed by this approach, where the real scenario obtained from performing a reverse stress test was never among the removed scenarios. Moreover, the initial multiplier approximation could be used when the scenario matrix contains a certain type of risk factors. Finally, this study shows that the current bisection algorithm can be optimized by the Newton-Raphson algorithm and Halley's algorithm.
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Phillips, Hannah(Hannah Michelle). "A data-driven approach to continuous improvement in reverse logistics." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/126915.
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Thesis: M.B.A., Massachusetts Institute of Technology, Sloan School of Management, in conjunction with the Leaders for Global Operations Program at MIT, May, 2020Thesis: S.M., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, in conjunction with the Leaders for Global Operations Program at MIT, May, 2020
Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 78-79).
Verizon may rely on third-party logistics providers (3PLs) to manage some aspects of the reverse supply chain of Fios equipment. As a result, it depends on the 3PL to continually strive for increased quality, reliability, capacity, and speed. Above all, in order to have a successful partnership, the process must be economical for the 3PL. As several sources of variation are detrimental to the 3PL's margins and cause operational problems, Verizon is investing in the supplier relationship to ensure that the 3PL is profitable and positioned for the future. Making sure there is a "win-win" relationship is beneficial for both parties and helps to ensure that the investments that have been made will continue to result in success, including operational improvements. To do this, a culture of continuous improvement and data-driven decisions needs to be cultivated and developed at the 3PL. The goal of this project is two-fold. First, there is a need to understand the variation that exists in the 3PL's process as well as the associated costs, which include overtime, ineffective labor and production planning, and high turnover. The secondary goal of the project is to empower the 3PL to make data-driven decisions in the future and start to shift their culture to one that aligns better with Verizon's. By showing the benefits of collaboration between the two companies, this project will help build trust. In this thesis, we discuss how process mining is used to understand the 3PL's current state and guide data-driven continuous improvement. We introduce several opportunities for handling variation, including creating visibility into return volumes, reducing defects caused by incorrect packaging, and creating feedback mechanisms for operators. This is done in close collaboration with the 3PL to ensure they will ultimately have ownership of implementation.
by Hannah Phillips .
M.B.A.
S.M.
M.B.A. Massachusetts Institute of Technology, Sloan School of Management
S.M. Massachusetts Institute of Technology, Department of Civil and Environmental Engineering
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Uichanco, Joline Ann Villaranda. "Data-driven revenue management." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/41728.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2007.Includes bibliographical references (p. 125-127).
In this thesis, we consider the classical newsvendor model and various important extensions. We do not assume that the demand distribution is known, rather the only information available is a set of independent samples drawn from the demand distribution. In particular, the variants of the model we consider are: the classical profit-maximization newsvendor model, the risk-averse newsvendor model and the price-setting newsvendor model. If the explicit demand distribution is known, then the exact solutions to these models can be found either analytically or numerically via simulation methods. However, in most real-life settings, the demand distribution is not available, and usually there is only historical demand data from past periods. Thus, data-driven approaches are appealing in solving these problems. In this thesis, we evaluate the theoretical and empirical performance of nonparametric and parametric approaches for solving the variants of the newsvendor model assuming partial information on the distribution. For the classical profit-maximization newsvendor model and the risk-averse newsvendor model we describe general non-parametric approaches that do not make any prior assumption on the true demand distribution. We extend and significantly improve previous theoretical bounds on the number of samples required to guarantee with high probability that the data-driven approach provides a near-optimal solution. By near-optimal we mean that the approximate solution performs arbitrarily close to the optimal solution that is computed with respect to the true demand distributions.
(cont.) For the price-setting newsvendor problem, we analyze a previously proposed simulation-based approach for a linear-additive demand model, and again derive bounds on the number of samples required to ensure that the simulation-based approach provides a near-optimal solution. We also perform computational experiments to analyze the empirical performance of these data-driven approaches.
by Joline Ann Villaranda Uichanco.
S.M.
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Tam, Ka-wing. "Feature based reverse engineering for thermoforming mould design /." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B36537196.
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Matic, (Mihelcic) Sanja. "Reverse Mortgage as an Option for Funding Retirement." Thesis, Jönköping University, JIBS, Economics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-12414.
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Sanli, Ozgur. "A Reverse Proxy For Protecting Web Based Applications." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/4/1230382/index.pdf.
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Palthepu, Srinivas. "Scalable program recognition for knowledge-based reverse engineering." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0018/NQ37907.pdf.
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Dunnewijk, Jeroen. "Reverse flow adsorption technology for homogeneous catalyst recycling." Enschede : University of Twente [Host], 2006. http://doc.utwente.nl/57601.
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Magdalinos, Christos. "An information retrieval tool for reverse software engineering." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=24025.
Full textAbstract:
Information retrieval in large data spaces using formal, structure oriented patterns of features has many possible applications. We developed and studied a system that can be used to localize code segments in a program. The system is built using a generic and extensible object oriented framework and uses the Viterbi dynamic programming algorithm on simple Markov models to calculate a similarity measure between an abstractly described code segment and a possible instantiation of it in the program. The resulting system can be incorporated in a larger cooperative environment of CASE tools and can be used during the design recovery process to perform concept localization.
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Tam, Ka-wing, and 譚家榮. "Feature based reverse engineering for thermoforming mould design." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B36537196.
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Herzog, Petra [Verfasser]. "Reverse genetics for Human Coronavirus NL63 / Petra Herzog." Bonn : Universitäts- und Landesbibliothek Bonn, 2015. http://d-nb.info/1080561269/34.
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Bouma, Andrew Thomas. "Split-feed counterflow reverse osmosis for brine concentration." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/118668.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 73-77).
Brine concentration is a useful operation that allows for increased recovery ratios in water treatment systems, reduction of waste volumes, and the production of minerals from saline brines. As our world moves towards a more sustainable future, improvements in energy-efficient brine concentration will be important. While viable brine concentration technologies exist, current methods are often inefficient. In this thesis, a model is developed to simulate Counterflow Reverse Osmosis (CFRO), a membrane-based, pressure-driven brine concentration technology. Using this model, a single CFRO module is simulated and its performance characterized. Entropy generation within a single-stage system is analyzed, which provides insights for configuring and optimizing multistaged systems. Additionally, a parametric analysis of membrane parameters provides direction for the development of CFRO-specific membranes. Two existing configurations of CFRO are discussed, and compared with a new third configuration, split feed CFRO, which is presented for the first time here. Split feed CFRO systems are simulated and optimized to provide guidance for system design. A variety of multistage systems operating at a range of recovery ratios are simulated, and the results compared are with existing desalination and brine concentration technologies. Potential is shown for the maximum recovery ratio of RO systems to increase significantly when hybridized with split-feed CFRO brine concentration systems, while the energy requirements of these hybridized systems is similar to, or an improvement on, the expected performance of conventional RO systems operating at high pressures and the same conditions. A large reduction in energy usage when compared to commonly used evaporative brine concentrators is shown to be possible.
Funded by the Kuwait Foundation for the Advancement of Sciences (KFAS) Project No. P31475EC01
by Andrew Thomas Bouma.
S.M.
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Kovacs, Jason Richard. "Engineering nanostructured selective layers for reverse osmosis membranes." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98709.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemical Engineering, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 122-142).
A major challenge to communities across the world in the next century will be ensuring millions have access to adequate freshwater resources. Studies from the UN World Health Organization indicate that over 1.1 billion people currently lack access to reliable and secure freshwater supplies, with an estimated 2.5 million deaths per year from diseases associated with poor access and sanitation in 2007. Reverse osmosis (RO), a process through which water is desalted via pressurized flow past a salt-selective membrane, is an energy-efficient method to generate freshwater from oceanic, brackish, and waste water sources. However, there are a number of challenges to scaling up RO processes to large scale production, including the need to improve membrane selectivity and throughput. One method to assemble selective layers for RO membranes is layer-by-layer (LbL) assembly, which is a flexible, scalable assembly technique that enables the incorporation of a myriad of polyelectrolytes and inorganic nanoparticles into thin films. There is a gap in the scientific literature concerning the use of LbL to generate RO selective layers where previous approaches have not taken full advantage of the LbL process to incorporate nanomaterials that can generate ordered nanostructures for salt rejection. In particular, high-aspect ratio clay platelets are ideal for such a purpose; it was hypothesized that effective salt rejection could be achieved by hindering the diffusion of solvated ions through nano-channels formed by the platelets embedded within a polymer matrix. This body of work examines the application of spray layer-by-layer (spray-LbL) assembly with clay composite thin film architectures to generate nanostructured selective layers for use in RO membrane technology. First, appropriate substrates were identified as support layers for the deposition of spray- LbL assembled clay composite thin films. Both electrospun bisphenol-A polysulfone (PSU) mats of varying fiber diameter and polyethersulfone (PES) ultrafiltration (UF) membranes with varying pore diameters were examined. Second, a range of materials were investigated for the spray-LbL deposition of clay composite films. Laponite clay platelets were incorporated into several different film architectures including strong polyelectrolytes as well as cross-linkable weak polyelectrolytes to form both bilayer and tetralayer film architectures. The clay content was controlled via manipulating assembly conditions such as the pH and spray times of the film components. Assembled membrane architectures were tested at industrial RO operating conditions in dead-end permeation cells and evaluated for salt rejection, water permeability, and mechanical strength. Ultimately, it was determined the most uniform and robust films were those deposited on PES membranes with 30 nm pores, closely matching the characteristic length of the LAP clay platelets to reduce the impact of bridging. Although all the film architectures tested exhibited significantly greater water permeability than commercially available RO selective layers, the salt selectivity was found to be highly dependent on the film architecture and assembly conditions. The best performing film architecture consisted of a cross-linked clay composite tetralayer film, exhibiting salt rejection of 89% for aqueous 10,000 ppm NaCl solution with an order of magnitude increase in water permeability over a commercially-available thin film composite membrane. The key conclusion drawn from the studies indicate the presence of an optimal zone where the incorporation of clay platelets introduces additional salt selectivity via size exclusion, balanced with the cross-linked polymer component of the film to improve the mechanical strength and reduce the risk of critical defect formation during operation. Taken together, these investigations represent a new approach using structured nanomaterials to develop next generation clay composite RO selective layers. The increased water permeability of the clay composite selective layers offers an attractive advantage in desalting applications where high flux is desirable, such as with brackish water resources as well as in membrane unit operations near their thermodynamic limit.
by Jason Richard Kovacs.
Ph. D.
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Detrich, Kahlil. "Electroding Methods for in situ Reverse Osmosis Sensors." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/31207.
Full textAbstract:
The purpose of this work is to develop and evaluate electroding methods for a reverse osmosis (RO) membrane that results in an in situ sensor able to detect RO membrane protein fouling. Four electroding techniques were explored: i) gold exchange-reduction, ii) encapsulated carbon grease, iii) â direct assembly processâ (DAP), and iv) platinized polymer graft. The novel platinized polymer graft method involves chemically modifying the RO membrane surface to facilitate platinization based on the hypothesis that deposition of foulant on the platinized surface will affect platinum/foulant/solution interfacial regions, thus sensor impedance. Platinized polymer graft sensors were shown to be sensitive to protein fouling.
Electrodes were characterized by their electrical properties, SEM and XPS. Assembled sensors were evaluated for sensitivity to electrolyte concentration and protein fouling. Micrographs showed coating layers and pre-soak solution influence gold exchange-reduction electrode formation. High surface resistance makes gold exchange-reduction an unsuitable method. Concentration sensitivity experiments showed carbon grease and DAP electroding methods produce unusable sensors. Carbon grease sensors have time-dependent impedance response due to electrolyte diffusion within the micro-porous polysulfone support. DAP electroded sensors proved quite fragile upon hydration; their impedance response is transient and lacks predictable trends with changes in concentration. A parametric study of the platinized polymer graft method shows amount of grafted monomer correlates to grafting time, and deposited platinum is a function of exchange-reduction repetitions and amount of grafted monomer. Platinized polymer graft sensors were fouled in both dead-end and cross-flow RO systems, and their impedance trends, while varying between sensors, indicate protein-fouling sensitivity.Master of Science
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Harrison, Don. "Solar powered reverse osmosis desalination for remote communities." Thesis, Harrison, Don (1989) Solar powered reverse osmosis desalination for remote communities. Honours thesis, Murdoch University, 1989. https://researchrepository.murdoch.edu.au/id/eprint/40085/.
Full textAbstract:
Many Aboriginal Outstations in Western Australia have bores which produce drinking water of such a low standard that the health of the community members is at risk. Major concerns are the high concentrations of sale, nitrates and fluoride and bacteriological contamination. Communities faced with this problem have four choices. They can sink another bore nearby in the hope of finding better water, which would be expensive and not necessarily successful. They can physically move to another location which would be socially and culturally disruptive. They can accept the risk and drink the water untreated. Recent innovations in reserve osmosis desalination now make it possible to treat the water on site using solar power.
The appropriateness of this new technology for remote locations is analysed. A means of predicting the power requirements of a unit capable of supplying the drinking water needs of a small community, estimated at up to 1 m3 per day is derived. A small commercially available unit was tested and it was found that in summer it could produce a steady flow of over 5 L/hour for 10 hours per day when used with a solar tracker and a power optimiser. Two designs were developed which could supply the desired 1 m3 flow rate from the power of two 55 W solar panels. A prototype of one design has been constructed and early testing demonstrate that is is capable of producing up to 400 L/day even at low pump efficiencies. Minor improvements are likely to substantially improve production in the near future.
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Black, Paul. "Techniques for the reverse engineering of banking malware." Thesis, Federation University of Australia, 2020. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/175276.
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Malware attacks are a significant and frequently reported problem, adversely affecting the productivity of organisations and governments worldwide. The well-documented consequences of malware attacks include financial loss, data loss, reputation damage, infrastructure damage, theft of intellectual property, compromise of commercial negotiations, and national security risks. Mitiga-tion activities involve a significant amount of manual analysis. Therefore, there is a need for automated techniques for malware analysis to identify malicious behaviours. Research into automated techniques for malware analysis covers a wide range of activities. This thesis consists of a series of studies: an anal-ysis of banking malware families and their common behaviours, an emulated command and control environment for dynamic malware analysis, a technique to identify similar malware functions, and a technique for the detection of ransomware. An analysis of the nature of banking malware, its major malware families, behaviours, variants, and inter-relationships are provided in this thesis. In doing this, this research takes a broad view of malware analysis, starting with the implementation of the malicious behaviours through to detailed analysis using machine learning. The broad approach taken in this thesis differs from some other studies that approach malware research in a more abstract sense. A disadvantage of approaching malware research without domain knowledge, is that important methodology questions may not be considered. Large datasets of historical malware samples are available for countermea-sures research. However, due to the age of these samples, the original malware infrastructure is no longer available, often restricting malware operations to initialisation functions only. To address this absence, an emulated command and control environment is provided. This emulated environment provides full control of the malware, enabling the capabilities of the original in-the-wild operation, while enabling feature extraction for research purposes. A major focus of this thesis has been the development of a machine learn-ing function similarity method with a novel feature encoding that increases feature strength. This research develops techniques to demonstrate that the machine learning model trained on similarity features from one program can find similar functions in another, unrelated program. This finding can lead to the development of generic similar function classifiers that can be packaged and distributed in reverse engineering tools such as IDA Pro and Ghidra. Further, this research examines the use of API call features for the identi-fication of ransomware and shows that a failure to consider malware analysis domain knowledge can lead to weaknesses in experimental design. In this case, we show that existing research has difficulty in discriminating between ransomware and benign cryptographic software. This thesis by publication, has developed techniques to advance the disci-pline of malware reverse engineering, in order to minimize harm due to cyber-attacks on critical infrastructure, government institutions, and industry.Doctor of Philosophy
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Susanto-Lee, Robertus. "Efficiency improvements for small-scale reverse-osmosis systems." Thesis, Curtin University, 2006. http://hdl.handle.net/20.500.11937/286.
Full textAbstract:
The water supplies of some small inland communities may come in the form of river systems that offer brackish water. Not fit for immediate human consumption, the water can be further processed using reverse osmosis to be converted into drinking water.In very remote areas there are limited energy resources, and for those areas that lie beyond a municipal distribution grid, renewable energy sources may be used. A reverse osmosis system that operates from the limited power generated by a renewable energy system must do so with the utmost of efficiency. Three methods in improving the efficiency of small-scale reverse-osmosis system are investigated, namely high-pressure pump speed control, feed water heating and vacuum pump based energy recovery.
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Susanto-Lee, Robertus. "Efficiency improvements for small-scale reverse-osmosis systems." Curtin University of Technology, Department of Electrical Engineering, 2006. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=16974.
Full textAbstract:
The water supplies of some small inland communities may come in the form of river systems that offer brackish water. Not fit for immediate human consumption, the water can be further processed using reverse osmosis to be converted into drinking water.In very remote areas there are limited energy resources, and for those areas that lie beyond a municipal distribution grid, renewable energy sources may be used. A reverse osmosis system that operates from the limited power generated by a renewable energy system must do so with the utmost of efficiency. Three methods in improving the efficiency of small-scale reverse-osmosis system are investigated, namely high-pressure pump speed control, feed water heating and vacuum pump based energy recovery.
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Petersen, Brian J. (Brian Jude). "Reverse supply chain forecasting and decision modeling for improved inventory management." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/80988.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division; and, (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; in conjunction with the Leaders for Global Operations Program at MIT, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 69-71).
This thesis details research performed during a six-month engagement with Verizon Wireless (VzW) in the latter half of 2012. The key outcomes are a forecasting model and decision-support framework to improve management of VzW's reverse supply chain inventory. The forecasting model relies on a reliability engineering formulation and incorporates a learning component to allow incremental forecast improvement throughout the device lifecycle. The decision-support model relies on Monte Carlo simulations to quantify the uncertainty and risk associated with different inventory management policies. These tools provide VzW stakeholders with a full-lifecycle perspective so that inventory planners can avoid costly end-of-life underages and overages. Prior to this effort, inventory planners at VzW relied on a three month returns forecast despite the fact that customers can return devices more than three years after launch. The decision-support model replaces existing heuristics to improve inventory management. Model efficacy is demonstrated through case studies. For a variety of representative SKUs, the returns forecast model is found to predict cumulative lifecycle returns within 10% using data available six months from launch. Had inventory been managed according to the policies recommended by the decision support model instead of policies from existing heuristics, VzW could have avoided an end-of-life stockout of more than 20,000 devices for a particular SKU.
by Brian J. Petersen.
M.B.A.
S.M.
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Göpfert, Johannes Georg. "Model-based fault diagnosis via structural analysis of a reverse osmosis plant." Master's thesis, Pontificia Universidad Católica del Perú, 2021. http://hdl.handle.net/20.500.12404/19043.
Full textAbstract:
Water desalination is one approach to force water scarcity. One of the processes used for
desalination is reverse osmosis. Like other systems, a reverse osmosis plant is susceptible to
faults. A fault can lead to a loss of efficiency, or if the fault is severe to a total breakdown.
Appropriate measures can minimize the impact of faults, but this requires in time fault
detection.
The following thesis shows a proposal for an online fault diagnosis system of a reverse
osmosis plant. For the model-based approach, a mathematical model of a reverse osmosis
plant has been developed. The model contains a new approach for modeling the interaction
between the high-pressure pump, the brine valve, and the membrane module. Furthermore,
six faults considered for fault diagnosis have been modeled. Two of the faults are plant
faults: The leakage of the feed stream and membrane fouling. The other four faults are
sensor or actuator malfunctions.
The fault diagnosis system is developed via structural analysis, a graph-based approach to
determine a mathematical model’s overdetermined systems of equations.
With the structural analysis, 73 fault-driven minimal structurally overdetermined (FMSO)
sets have been determined. The results show that all six faults are detectable. However, two
faults are not isolable. Five of the FMSO sets have been chosen to deduce the residuals used
for online fault detection and isolation. The simulations demonstrate that the calculated
residuals are appropriate to detect and isolate the faults. If one assumes that only the
considered faults occur, it is possible to determine some faults’ magnitude.
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Borja, Ramirez Vicente. "Redesign supported by data models with particular reference to reverse engineering." Thesis, Loughborough University, 1997. https://dspace.lboro.ac.uk/2134/11705.
Full textAbstract:
The research reported in this thesis is focused on the creation of a CAE system to support Reverse Engineering. It is centred around the computational representation of products (Product Model) and manufacturing capabilities (Manufacturing Model). These models are essential for modem and future software systems aimed to assist the design process, enabling data sharing among the participants who use various computational tools. Reverse Engineering is employed as a particular context and motivation for exploring the application of the models. The research builds on the achievements of the recently finished Model Oriented Simultaneous Engineering System (MOSES) project, undertaken jointly by Leeds University and the Department of Manufacturing Engineering of Loughborough University. MOSES' work on information modelling was analysed and combined together with the original proposals of the author to elaborate a suitable support to Reverse Engineering, applicable to redesign in general. A process for Reverse Engineering is proposed and documented and a data model driven CAE system to support it is specified. The CAE system includes a Product Model, a Manufacturing Model and two software application environments. The Product Model of the system is based on the information requirements of the Reverse Engineering process and is suitable for representing multi-component products, from different perspectives through its life cycle. The applications assist the characteristic activities of Reverse Engineering. In particular, the system is used for exploring the application of Product and Manufacturing Models in supporting Design for Manufacture. The theoretical research is tested by the use of a case study which explores the Reverse Engineering of a component. This work is supported by a prototype software instance of the CAE system. The case study component is an axle which forms part of a product designed and manufactured by a collaborating company.
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Roll, Bruce A. "Online reverse auctions : a pricing tool for government contracting /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2000. http://handle.dtic.mil/100.2/ADA386693.
Full textAbstract:
Thesis (M.S. in Management) Naval Postgraduate School, Dec. 2000.Thesis advisors, Nissen, Mark E. ; Gates, William R. "December 2000." Includes bibliographical references (p. 63-64). Also available online.
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Massons, Gassol Gerard. "Biofouling control in reverse osmosis membranes for water treatment." Doctoral thesis, Universitat Rovira i Virgili, 2017. http://hdl.handle.net/10803/461092.
Full textAbstract:
L’osmosi inversa (OI) és una de les tecnologies de purificació d'aigua més competitives. Els sistemes d'OI han evolucionat significativament en els últims anys per a proporcionar solucions reals i sostenibles als problemes relacionats amb l'aigua. Un dels principals obstacles que impedeix l'expansió en l'ús d'OI en la reutilització de l'aigua, és la pèrdua de rendiment que els elements d'OI experimenten a l'operar amb aigües contaminades. Aquest fenomen de embrutament continua sent un dels majors reptes a resoldre per elements de OI utilitzats en plantes industrials o de tractament d'aigües residuals.
A causa de la complexitat d'estudiar aquests problemes en sistemes d'escala industrial, és necessari desenvolupar protocols per reproduir els efectes en equips de laboratori. Els efectes de l’embrutament solen apareixer després de diversos mesos. No obstant, per poder realitzar la recerca en un temps realista, el procés ha ser accelerat de forma controlada i el més realista possible. S'ha estudiat l'efecte de diferents variables operacionals en el desenvolupament de l’embrutament biològic. També s'ha avaluat el paper dels paràmetres de construcció de mòduls d'OI, provant en paral·lel diferents membranes i espaciadors, per millorar el disseny d'elements resistents al embrutament.
Els resultats dels assaigs realitzats demostren clarament que diferents químiques de membrana poden proporcionar una reducció significativa en els nivells de embrutament. Tot i això, es va trobar que el principal contribuent al desenvolupament dels biofilms es el espaciador. El disseny de l'espaciador es va estudiar en detall per aconseguir un comportament equilibrat en mòduls d'OI que tracten aigües amb un risc d’embrutament biològic elevat. Es van probar espaciadors amb diferents espessors, separacions i angles. Alguns dissenys van mostrar avantatges en la perdua de pressió generada, així com en l'acumulació d’embrutament biològic i orgànic.La osmosis inversa (OI) es una de las tecnologías de purificación de agua más competitivas. Los sistemas de OI han evolucionado significativamente en los últimos años para proporcionar soluciones reales y sostenibles a los problemas relacionados con el agua. Uno de los principales obstáculos que impide la expansión del uso de OI en la reutilización del agua es la pérdida de rendimiento que los elementos de OI experimentan al operar con aguas contaminadas. Este fenómeno de ensuciamiento sigue siendo uno de los mayores desafíos para los elementos de OI utilizados en plantas industriales o de tratamiento de aguas residuales. Debido a la complejidad de estudiar estos problemas en sistemas de escala industrial, es necesario desarrollar protocolos para reproducir los efectos en equipos de laboratorio. Los efectos del ensuciamiento suelen ocurrir después de varios meses. Sin embargo, para poder realizar la investigación en un tiempo realista, el proceso necesita ser acelerado de manera controlada y lo más realista posible. Se ha estudiado el efecto de diferentes variables operacionales en el desarrollo del ensuciamiento biológico. También se ha evaluado el papel de los parámetros de construcción de módulos de OI, probando en paralelo diferentes membranas y espaciadores, para mejorar el diseño de elementos resistentes al ensuciamiento. Los resultados de los ensayos realizados mostraron claramente que diferentes químicas de membrana pueden proporcionar una reducción significativa en los niveles de bioensuciamiento. Sin embargo, se encontró que el principal contribuyente al desarrollo de biofilms fue el espaciador. El diseño del espaciador se estudió en detalle para lograr un comportamiento equilibrado en módulos de OI que tratan aguas propensas al ensuciamiento biológico. Se ensayaron espaciadores con diferentes espesores, espaciamiento y ángulo. Algunos diseños mostraron ventajas en la perdida presión generada, así como en la acumulación de ensuciamiento biológico y orgánico.
Reverses osmosis (RO) filtration is one of the most competitive water purification technologies. RO systems have evolved significantly in the last years to provide real and sustainable solutions to water-related problems. One of the main hurdles that hinders RO expansion in water reuse, is the loss of performance that RO elements suffer when dealing with contaminated waters. This phenomenon known as fouling, remains to be one of the biggest challenges for RO elements used in industrial or wastewater treatment plants. Due to the complexity to study these problems in large scale systems, protocols need to be developed in order to mimic full-scale plants operation on a bench scale. Fouling problems are usually occurring after several month of operations. However, for a realistic time-scale research, the process needs to be accelerated in a controlled way and as similar as possible to what would be occurring naturally. The effect of different operating variables on biofouling development was studied. The role of RO module construction was also evaluated, testing different membranes and feed spacers side-by-side, to guide the improvements on the design of fouling resistant elements. The results from the trials performed clearly showed that different membrane chemistries can provide significant reduction in the levels of biofouling detected after operation. However, it was found that the main contributor to biofilm development was feed spacer. Large differences in the amount of biofouling generated could be associated with feed spacer presence. Feed spacer design was then studied in detail to achieve a balanced performance in spiral wound RO modules treating waters prone to biofouling. Feed spacers with various thickness, spacing and angle were tested and some designs showed advantages in pressure drops, as well as on biologic and organic fouling accumulation.
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Malmsten, Anders. "Reverse Transcriptase Activity Assays for Retrovirus Quantitation and Characterization." Doctoral thesis, Uppsala University, Department of Genetics and Pathology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4737.
Full textAbstract:
Reverse transcriptase (RT) is a crucial enzyme for retrovirus replication, and its presence in the virion is indispensable for infectivity. This thesis illustrates the use of RT activity assays as tools for quantitation and characterization of different retroviruses, particularly HIV.
A non radioactive assay, using microtiter plates, for the RT of Moloney murine leukemia virus (MMuLV) was developed. Assay conditions for MMuLV and HIV-1 RT, together with isozyme specific RT activity blocking antibodies, were shown useful for discrimination between RTs from different retrovirus genera. RT activity assay for HIV-1 was found to quantitate different subtypes more equally efficient than p24 antigen assays did.
Viral load (VL), the amount of HIV particles in the blood, is an important marker of the clinical status of an infected person. A method for VL determination based on RT activity (ExaVir Load) was developed. After plasma pretreatment, to inactivate cellular DNA polymerases, virions in patient plasma were immobilized on a gel, which was washed to remove disturbing factors. The virions were lysed with a detergent containing buffer and the lysate eluted. Finally, the RT activity in the lysate was determined and found to correlate strongly to VL by RNA according to a PCR based standard method (Roche Amplicor 1.5). The second version of the method was able to measure VL down to approximately 400 HIV-1 RNA copies/ml. The usefulness of RT from the VL procedure for determination of susceptibility towards anti-HIV drugs was demonstrated, and the results were in agreement with genotypic data.
Due to its technical simplicity, and ability to detect a broad range of HIV-1 subtypes, ExaVir Load and the drug susceptibility application are interesting for clinical use, particularly but not only in resource limited settings. The concept is also potentially useful for research purposes, e.g. in combination with specific RT assay conditions.
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Anpalagan, Subramaniam Alagan. "Reverse link channel access techniques for CDMA packet networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/NQ63640.pdf.
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Corrigan, Gary E. "Evaluation of reverse transcriptase assay for viral load monitoring /." Stockholm, 2007. http://diss.kib.ki.se/2007/978-91-7357-207-1/.
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Chamberlain, Philip Paul. "Structural mechanisms of drug resistance for HIV reverse transcriptases." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403941.
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Saibani, Nizaroyani. "Performance measurement for reverse and closed-loop supply chains." Thesis, University of Nottingham, 2010. http://eprints.nottingham.ac.uk/12102/.
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Supply chains today continue to have shorter life-cycle products as a result of high rates of innovation. The increasing number of electronic retailing and catalogue sales fulfil the requirement of home shopping. More liberal return policies have been introduced to protect customers' buying rights and at the same time generate more sales. A growing number of environmental regulations are created which involve a wide range of products. All of these circumstances contribute to the reverse flow of products which require manufacturing organisations to strategically manage and deal with the return flows. Reverse supply chains or reverse logistics have attracted the attention of many academics and practitioners and one of the important field studies in this area is of Supply Chain Management. To contribute to the field, this research is purposely carried out to study the performance measurement in reverse supply chains. Reverse logistics networks may be classified into several categories depending on the source of the reverse flow. This research will focus on customer and distribution return flows. The research is significant because there is a gap in the literature and it could help to give companies guidance in managing their reverse supply chains better. Case studies on five companies which include manufacturers and retailers in the UK provide empirical evidence for their practice of performance measurement in reverse supply chains. The research investigates the selection of strategic objectives for reverse supply chains and the impact of product returns' characteristics and the choice of product returns disposition channels. Learning from the performance measurement in a reverse supply chain, the research proposes a three-level performance measurement framework model for reverse and closed-loop supply chains. This framework model provides the decision makers with a formal and systematic approach to select strategic objectives and towards the use of meaningful performance attributes and performance metrics. Subsequently, it offers a practical approach to the decision maker to perform and manage the reverse supply chain more effectively.
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El, Barky Sahar Sobhy. "An enhanced method for core assessment in reverse logistics." Thesis, University of Strathclyde, 2011. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=18808.
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Gorlow, Stasnislaw. "Reverse audio engineering for active listening and other applications." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00959329.
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This work deals with the problem of reverse audio engineering for active listening. The format under consideration corresponds to the audio CD. The musical content is viewed as the result of a concatenation of the composition, the recording, the mixing, and the mastering. The inversion of the two latter stages constitutes the core of the problem at hand. The audio signal is treated as a post-nonlinear mixture. Thus, the mixture is "decompressed" before being "decomposed" into audio tracks. The problem is tackled in an informed context: The inversion is accompanied by information which is specific to the content production. In this manner, the quality of the inversion is significantly improved. The information is reduced in size by the use of quantification and coding methods, and some facts on psychoacoustics. The proposed methods are applicable in real time and have a low complexity. The obtained results advance the state of the art and contribute new insights.
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Shen, Guoling 1967. "Approximation with interval B-splines for robust reverse engineering." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43456.
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Nurminen, F. C. (Fiia-Charlotta). "Probabilistic model of fault displacement hazard for reverse faults." Master's thesis, University of Oulu, 2018. http://urn.fi/URN:NBN:fi:oulu-201809152805.
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Probabilistic fault displacement hazard analysis (PFDHA) is a method development for assessment of the fault rupture hazard and the amount and distribution of co-seismic fault displacement. The method has been developed for normal faulting tectonic settings and developed further for being suitable for strike-slip fault types. For the thrust fault settings, only the parts regarding the probability and the amount of displacement on the primary fault have been examined, but the analysis of the distributed faulting in reverse fault environments has been lacking in the scientific discussion. The purpose of this thesis is to create a probabilistic model for predicting the surface deformation related hazard in thrust fault environments. The analysis of this thesis is based on the analysis of empirical database gathered from 11 historical, well-studied thrust earthquakes. The database was used in the analysis of the spatial distribution of secondary surface rupturing and establishing the attenuation relationships to the amount of dislocation for the increasing distance from the principal fault. The general methodology followed the one defined by previous authors for the PFDHA, but especially for the analysis of the distributed fault rupturing several methodological decisions needed to be done during the work to obtain a statistically robust and reliable model that could be used for prediction purposes. The model utilizes as input the parameters derived from the calculation of the probability of the occurrence, and the amount of distributed faulting, as well as the surface geometry of the fault to be modelled. The model computes the probability of the secondary rupturing exceeding a certain displacement level, or the amount of the secondary slip with a given probability using a 10 x 10 m grid. Together the values computed to all the grid points separately form continuities that can be illustrated on a map. This enables the location specific analysis of the seismic hazard. In the last section of this work the developed model is applicated to the Suasselkä post-glacial fault, situated in Northern Finland. The application is done for a scenario where the fault ruptures for its total surface rupture length, and the probability of surface deformation is analysed in the surroundings of the fault. The model created here can be applied to any well-known mapped fault trace of a reverse kinematics for estimating the seismic event related risk on specific locations around an active faultPFDHA-menetelmä (Probabilistic fault displacement hazard analysis) on kehitetty seismisiin siirrosvyöhykkeisiin liittyvän riskin sekä seismisen siirtymän määrän ja jakauman arviointiin. Menetelmä on kehitetty normaalisiirroksille, mutta sitä on kehitetty edelleen sivuttaissiirroksiin ja työntösiirroksiin sopivaksi. Työntösiiroksille on aiemmin kehitetty vain pääsiirroksen siirtymän todennäköisyyttä ja määrää kuvaavat laskelmat, mutta sekundäärisiirrosten analyysi on puuttunut tieteellisestä keskustelusta. Tämän pro gradu -tutkielman tarkoitus on luoda todennäköisyyksiin perustuva ennustusmalli, jota voidaan käyttää mallintamaan maanpinnan muutoksiin liittyvää riskiä työntösiirrosten ympäristössä. Tämän tutkielman analyysi perustuu 11 historiallisen, hyvin tutkittuun työntösiirrosmaanjäristykseen. Näistä luotua tietokantaa käytettiin sekundäärisiirrosten avaruudellisen jakauman arvioimiseen sekä sekundäärirepeämisen vaimenemissuhteen analysoimiseen etäisyyden pääsiirrokseen kasvaessa. Käytetty menetelmä perustuu pääpiirteissään perinteiseen PFDHA-menetelmään, mutta erityisesti näiden sekundäärisiirrosten analyysin osalta menetelmää koskevia päätöksiä tuli tehdä työn edetessä, jotta lopputuloksena oli tilastollisesti pitävä ja uskottava malli, jota voidaan käyttää riskin arvioinnissa. Malli käyttää syötteenään sekundäärisiirrosten tapahtumisesta ja siirrosten suuruudesta johdettujen todennäköisyysfunktioiden muuttujia, sekä mallinnettavan siirroksen pintageometriaa. Malli laskee sekundäärirepeämän todennäköisyyden ylittää annettu siirtymä tai määritetyllä todennäköisyydellä tapahtuvan siirtymän suuruuden 10 x 10 m ruudukolla pääsiirroksen ympäristössä kullekin ruudulle erikseen. Yhdessä näille ruuduille lasketuista arvoista muodostuu jatkumoja, joita voidaan kuvata kartalla. Tämä antaa mahdollisuuden maanjäristykseen liittyvän seismisen riskin tarkkaan paikkakohtaiseen analyysiin. Työn viimeisessä osassa kehitettyä mallia sovelletaan Pohjois-Suomessa sijaitsevaan Suasselän jääkauden jälkeiseen työntösiirrokseen ja sen ympäristöön. Mallia sovelletaan skenaariolle, jossa siirros liikkuu koko pituudeltaan, ja maanpinnan liikuntojen todennäköisyyttä mallinnetaan siirroksen ympäristössä. Tässä työssä kehitettyä mallia voidaan soveltaa mille tahansa hyvin tunnetulle, aktiiviseksi määritellylle työntösiirrokselle siirroksen seismisen riskin arvioimiseen tietyissä kohteissa siirroksen ympäristössä
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Pas, Joshua W. "Contract and strategic network design for reverse production systems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22577.
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Thesis (Ph. D.)--Industrial and Systems Engineering, Georgia Institute of Technology, 2008.Committee Co-Chair: Ammons, Jane C.; Committee Co-Chair: Realff, Matthew J.; Committee Member: Griffin, Paul M.; Committee Member: Peoples, Robert; Committee Member: Thomas, Valerie.
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Nafziger, John S. "Reverse parameterization of B-spline surfaces for data transfer." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06302009-040414/.
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Harrison, Don. "Solar powered reverse osmosis desalination: Technology for remote communities." Thesis, Harrison, Don (2001) Solar powered reverse osmosis desalination: Technology for remote communities. PhD thesis, Murdoch University, 2001. https://researchrepository.murdoch.edu.au/id/eprint/52404/.
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The need for desalination to provide drinking water of acceptable standards has been established. A review of desalination techniques suggests that solar powered reverse osmosis with energy recovery is likely to satisfy the widest range of applications in inland Australia and elsewhere. Of the energy recovery techniques, the 'flow-regulated' approach appears well suited to remote applications, because it maintains its set recovery ratio regardless of insolation levels, and starts and stops automatically at sunrise and sunset. Operating and capital costs of units needs to be minimised and operational flexibility maximised for wide application in remote areas.
This project aimed to develop, produce and test a low cost solar powered desalinator that was portable, reliable and flexible. The thesis describes the theoretical and practical development of a production model through the four prototypes. The prototypes were tested to determine the performance of a variety of membranes, the efficiency of the pumps and energy recovery system, and the water slippage of valves and seals. The available energy from the two-panel tracking array was also assessed.
A model which describes the hydraulics of 'flow-regulated' energy recovery systems was developed and incorporated in a spreadsheet program and used to assess the performance of the prototypes. The relevance of all the variable components affecting fresh water production can be assessed through graphically presented results from the spreadsheet.
A production model solar powered desalinator capable of 400 L/day from a 120 W peak array has been developed as a result of the project. The flow-regulated approach to energy recovery appears to work well in the field and may be contributing to the maintenance of high water production rates at all sites without resorting to chemical pretreatment or frequent cleaning. High pulsation rates and low feed flow rates through large diameter spiral wound membranes do not appear to adversely affect membrane life at the low pressures used in these machines.
Further research is required to monitor the long term reliability and running costs of these machines, their degree of acceptance in remote communities, and their ability to maintain the quality of product water to acceptable standards.
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Eid, Roy George. "Reverse engineering toolbox for pedagogical applications." Thesis, 2012. http://hdl.handle.net/2152/ETD-UT-2012-05-5678.
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Reverse engineering, the technique of using different tools and methodology to recreate an object or machine, is increasingly used in academia to solidify theoretical concepts as part of the Kolb learning cycle. This thesis aims to aid the use of reverse engineering as a pedagogical tool by developing a toolbox that can be used by students, and professionals alike, to properly reverse engineer a mechanical or electro-mechanical product.
The development begins with an analysis of House of Quality matrices, a design methodology tool used by the industry to relate customer needs to engineering metrics and specifications. After a consolidated list of metrics was developed, the appropriate tools to properly quantify said metrics were researched and documented. Finally, a toolbox was created, with set goals in mind, and applied in two case studies to analyze its performance.
Simultaneously, a portable dynamometer was developed, documented, and tested, with the goal of creating an inexpensive and accessible tool to measure the power output of fractional horsepower DC and AC motors.text