In the field of linear regression analysis, a single outlier can dramatically influence ordinary least squares estimation while low-breakdown procedures such as M regression and bounded influence regression may be unable to combat a small percentage of outliers. A high-breakdown procedure such as least trimmed squares (LTS) regression can accommodate up to 50% of the data (in the limit) being outlying with respect to the general trend. Two available one-step improvement procedures based on LTS are Mallows 1-step (M1S) regression and Schweppe 1-step (S1S) regression (the current state-of-the-art method). Issues with these methods include (1) computational approximations and sub-sampling variability, (2) dramatic coefficient sensitivity with respect to very slight differences in initial values, (3) internal instability when determining the general trend and (4) performance in low-breakdown scenarios. A new high-breakdown regression procedure is introduced that addresses these issues, plus offers an insightful summary regarding the presence and structure of multivariate outliers. This proposed method blends a cluster analysis phase with a controlled bounded influence regression phase, thereby referred to as cluster-based bounded influence regression, or CBI. Representing the data space via a special set of anchor points, a collection of point-addition OLS regression estimators forms the basis of a metric used in defining the similarity between any two observations. Cluster analysis then yields a main cluster "halfset" of observations, with the remaining observations becoming one or more minor clusters. An initial regression estimator arises from the main cluster, with a multiple point addition DFFITS argument used to carefully activate the minor clusters through a bounded influence regression framework. CBI achieves a 50% breakdown point, is regression equivariant, scale equivariant and affine equivariant and distributionally is asymptotically normal. Case studies and Monte Carlo studies demonstrate the performance advantage of CBI over S1S and the other high breakdown methods regarding coefficient stability, scale estimation and standard errors. A dendrogram of the clustering process is one graphical display available for multivariate outlier detection. Overall, the proposed methodology represents advancement in the field of robust regression, offering a distinct philosophical viewpoint towards data analysis and the marriage of estimation with diagnostic summary. / Ph. D.

A large percentage of individuals with intractable epilepsies have an accompanying cortical malformation, the underlying cellular mechanisms of which are poorly understood. It is known however that in an animal model for one such malformation, polymicrogyria, epileptogenesis occurs most easily from an adjacent area termed the paramicrogyral region (PMR). Previous studies implicate SS interneurons as a potential contributor to this pathology, which lead to our hypothesis: in PMR, SS interneurons exert a higher modulatory influence on excitatory pyramidal cells, as compared to the same by SS interneurons within homologous control cortex. Using a freeze-lesion model for polymicrogyria in transgenic mice that selectively express either Channelrhodopsin or Archaerhodopsin optogenetic channels in these cells, we assessed the contribution of SS interneurons as it potentially differs between layer V of PMR and control cortex. These studies provided the following biological examples in support of previous extrapolations that indicate SS over-activation within PMR: (1) SS interneuron mediated evocation of inhibitory events in layer V excitatory neurons is more robust in PMR than in control. Similarly, electrically-evoked inhibitory events in these excitatory neurons trend towards being larger, signifying a larger contribution by interneurons. (2) SS interneuron mediated suppression of electrically-evoked responses trends towards being stronger in PMR; and (3) the selective silencing of SS interneurons might not impart an effect on spontaneous inhibitory postsynaptic events.

Epilepsy, defined by recurrent seizures, is the one of the most prevalent neurological disorders worldwide (World Health Organization 2007). While many forms of epilepsy are well-controlled by anti-epileptogenic medications, a significant portion of patients have intractable, i.e. untreatable, seizures. The etiology of these seizures is varied, but a significant cause, particularly for patients with intractable epilepsy is developmental malformation. In these cases, an error or interruption during the development of the neocortex produces a structural alteration. Such patients may have other neurological problems, but seizures are the most common symptom. The neuronal mechanisms that link malformation and cortical hyperexcitability are not well understood. Here we have sought to examine potential mechanisms that result from microgyria, a malformation characterized by excessive numbers of small gyri.The presence of epileptiform activity indicates that the normal balance of excitation and inhibition has shifted . Two functions of inhibition within neocortex are to prevent spread of excitation, and to modulate the timing of surrounding excitation. Although seemingly contradictory, increasing some forms of inhibition can result in an increase in synchronous excitatory activity. We hypothesize that for certain malformation epilepsies, the inhibitory processes that control timing are increased, creating a hyper-synchronous cortex, while the inhibitory processes that control horizontal spread are decreased, allowing the propagation of such activity. Here we have examined the network effect of selectively modulating the inhibitory cells that control vertical or columnar cortical synchrony. This modulation is performed via activation of metabotropic glutamate receptors found on the vertically-projecting interneurons but not on those inhibitory cells that control horizontal spread of activity. Our results suggest that the network effect of activating these interneurons is altered in malformed, epileptogenic cortex.

Understanding the future of a Large Technical System (LTS) through a sociotechnical analysis is a complex notion. The authors will investigate the phenomenon by studying residential water consumption in Sweden. Although Sweden has great access to raw water, compared to many other countries, it does not justify the fact that consumption patterns have to be unsustainable. To perceive the future, one will need to have knowledge of history. Therefore, this thesis has identified 11 drivers that will affect future residential water consumption. From these 11 drivers, the authors have posed four future scenarios for residential water consumption. The top 3 identified drivers are connected to behaviour and awareness. Thus, implying individuals' responsibility and accountability will be of greater significance for the sustainable development of residential water consumption. For this research, the authors have adopted a framework based on the application of LTS, Multi-Level Perspective (MLP), Scenario building, PESTLE, and Multi-Criteria Analysis (MCA). The authors have conducted a qualitative study, gathering data through a literature study and semi-structured interviews. The 18 interviewees covered a broad spectrum of knowledge, experiences, and general interest in water. By understanding the dynamics of the system and drivers, the authors will be able to present the gathered knowledge to stakeholders for possible strategic decisions. / Att förstå framtiden för ett stort tekniskt system (LTS) genom en socioteknisk analys innebär stor komplexitet. Detta kommer att undersökas genom att studera hushållens vattenförbrukning i Sverige. Även om Sverige har stor tillgång till råvatten, jämfört med många andra länder, berättigar det inte förekommandet av ohållbara konsumtionsmönster. För att öka förståelsen av framtiden måste en ha kunskap om historien. Därför har denna avhandling identifierat 11 drivkrafter som kommer att påverka den framtida hushållens vattenförbrukning. Från dessa 11 drivkrafter har författarna formulerat fyra framtida scenarier för hushållens vattenförbrukning. De tre högst rankade identifierade drivkrafterna är kopplade till beteende och medvetenhet. Detta antyder på att individens enskilda ansvar och skyldigheter är av större betydelse för en hållbar utveckling av hushållens vattenförbrukning. För denna forskning har författarna använt sig av ett teoretiskt ramverk som bygger på tillämpningen av LTS, Multi-Level Perspective (MLP), Scenario building, PESTLE and Multi-Criteria Analysis (MCA). Författarna har genomfört en kvalitativ studie, där insamling av data härstammar från den genomförda litteraturstudien och 18 semi-strukturerade intervjuer. De 18 intervjukandidaterna täckte ett brett spektrum av kunskap, erfarenhet och intresse av vatten. Genom att skapa ett samband och förstå dynamiken i systemet och drivkrafterna, kommer författarna att kunna presentera den samlade kunskapen till intressenter för eventuella strategiska beslut.

Den här studien utgår ifrån två svenska koppargruvor varav den ena, Aitik i Gällivare, är idrift och den andra, Falu gruva, stängde 1992. Studiens syfte är att undersöka förutsättningarna för att använda Falu gruva som modell för den framtida avvecklingen av Aitik, med särskilt avseende på efterbehandling, kulturarvsprocesser och återanvändning. Inom ramen för kulturarvsprocesser och återanvändning beaktas särskilt lärande.Metodansatsen är kvalitativ och den teoretiska utgångspunkten är att en gruva kan ses som ett stort sociotekniskt system bestående av artefakter och sociala komponenter. Genom intervjuer med representanter från Falu gruvas ägare och Aitiks ägare samt från Gällivare kommun genererades data. Data från intervjuerna samt från en mindre dokumentstudieut gjorde studiens resultat. Detta analyserades tematiskt och diskuterades utifrån uppsatsens teoriavsnitt. Resultatet visar att Aitik kan utvecklas vid en framtida avveckling och att Falu gruva i vissa avseenden kan användas som modell för denna process. Bland annat kan Falu gruva användas som modell för Aitik avseende utbildning som en del av återanvändning, där Aitikkan lära av Falu gruva genom att inte göra samma misstag som gjorts där. Resultatet visar emellertid också att samhällena Gällivare och Falun skiljer sig mycket åt, både vad gäller samhällsidentitet och samhällets relation till gruvan. Slutsatsen av den här studien är att aspekter såsom att betrakta artefakter som en resurs; gruvans roll i samhället; samt vem som definierar kulturarv är centrala för att kunna använda Falu gruva som modell för Aitikmed hänsyn till lärande. / This study is about two Swedish copper mines, Aitik in Gällivare which is still in use and theFalun mine, which closed in 1992. The aim of this study is to explore the prerequisites for using the Falun mine as a model for the future closure of the Aitik mine, with regards specifically to mine reclamation, heritagisation and reuse. In particular, the aspect of learning within the heritagisation and reuse framework is discussed. A qualitative research method has been used and the theoretical starting point is that a mine can be seen as a large technological system consisting of artifacts and social components. Data has been collected through interviews with representatives from the Falun mine owners, the Aitik mine owners and from the local government of Gällivare. This data, along with data from a limited document study, made up the results of this study. The results were then analyzed thematically and discussed against the theoretical frameworks used in this study. The results show that Aitik can be developed post-closure and that the Falun mine can, ins ome regards, be used as a model for this development process. Among other aspects, theFalun mine can be used as a model for Aitik for education as a part of reusing the mine, where Aitik can learn from the Falun mine by not making the same mistakes that were made there. However, the results show that the Gällivare and Falun societies are different in terms of identity and in their relations towards the mines. The conclusion of this study is that aspects such as regarding artifacts as resources; the mine’s role in society; and who determines what a cultural heritage is, are all important in order to use the Falun mine as a model for Aitik from an educational perspective.

Made available in DSpace on 2014-06-12T15:59:48Z (GMT). No. of bitstreams: 1 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2007 / A especificação formal de um sistema ou seu modelo formal é uma forma abstrata de representar suas propriedades (características). Métodos formais é um ramo da Engenharia de Software com foco no desenvolvimento de sistemas tendo uma especificação formal do mesmo como ponto de partida. Inicialmente, as vantagens de usar notações abstratas antes da implementação do sistema estavam apenas relacionadas a um melhor entendimento do problema. Depois, tornou-se evidente que o uso de notações formais abstratas combinadas com técnicas de refinamentos de modelos reduzem o tempo de desenvolvimento e aumentam a qualidade do produto de sistema. A fase de testes é positivamente influenciada pelo uso de métodos formais. Pesquisas têm sido desenvolvidas para melhorar a qualidade do sistema usando modelos formais e casos de teste. Uma vez verificadas as propriedades do sistema através de uma investigação dos modelos formais, é possível gerar casos de testes confiáveis do sistema que serão colocados em ação para verificar a implementação do sistema posteriormente. O campo de pesquisa que explora métodos formais aplicados com testes de software é chamada de Testes Baseados em Modelos, ou simplesmente MBT, do inglês Model-Based Testing. Porém, há situações onde não é possível possuir o modelo abstrato definido a priori. Para superar tal restrição outras técnicas surgiram para sintetizar um modelo abstrato seguindo apenas execuções do sistema. As execuções de um sistema contêm comportamentos necessários para construir um modelo abstrato desse sistema. Na literatura atual, tais técnicas usadas para construir representações abstratas seguindo execuções do sistema são chamadas de Anti-Model- Based Testing ou simplesmented Anti-MBT. Então, depois de construir um modelo abstrato, técnicas de verificação de modelos e geração de casos de teste seguindo modelos formais podem ser aplicadas normalmente. O propósito desse trabalho é dar suporte a algumas técnicas de MBT usadas no contexto da Motorola (CIn/BTC). Em tais técnicas, as especificações usadas para gerar casos de testes são geralmente incompletas, inconsistentes, e às vezes não existem. Portanto, usando casos de testes reais do sistema é possível criar novas especificações e atualizar especificações originais do sistema, e posteriormente gerar novos casos de teste usando comportamentos válidos do sistema. Um outro problema detectado em nosso contexto é a distância existente entre as representações abstratas e reais. Um caso de teste abstrato, por exemplo, é útil em técnicas formais, mas não é possível executar um caso de teste diretamente no sistema. Dessa forma, para executar (manualmente ou automaticamente) os casos de teste gerados pelas técnicas de MBT é necessário primeiro traduzi-los em uma representação real. Como resultado desse trabalho nós desenvolvemos técnicas formais de modelagem do comportamento do sistema usando casos de teste. Os resultados das técnicas de modelagem são modelos formais especificados nos formalismos de LTS ou CSP. Além disso, nós definimos uma técnica de unificação que une modelos formais gerados a partir de diferentes artefatos do sistema (requisitos e casos de teste). O resultado da técnica de unificação é um completo e unificado modelo do sistema, que contém informações providas de diferentes artefatos. Nós também definimos uma técnica para traduzir casos de teste abstratos em representações reais. Os casos de teste reais gerados por nossa técnica de tradução são usados no contexto do time de automação de testes da Motorola, onde esse trabalho está inserido. Finalmente, nós automatizamos as técnicas desenvolvidas usando linguagens de programação e especificações formais. O resultado é a ferramenta TCRev que é capaz de modelar, unificar e traduzir modelos do sistema. A ferramenta TCRev interage com o outras ferramentas externas, tais como FDR e FDR Explorer. Todos os resultados foram validados em estudos de casos reais executados no contexto da Motorola. Nessa dissertação nós apresentamos um destes estudo de casos

Background:Scarcity refers to a basic economic problem, the gap between limited resources and limitlesswants. This situation requires people to make decisions on how to allocate resourcesefficiently in order to satisfy basic needs and as many additional wants as possible. Scarcitycan affect the consumers ability to source and process information with regards to acquiring ascarce product. Scarcity can be divided into two cues, LQS and LTS and these ques can helpunderstand a consumer's purchase intention.Purpose:The purpose of this paper is to explain the effect increasing LQS & LTS has on onlinepurchase intention onlineMethodology:This thesis employed a quantitative research method as well as a deductive approach with anexplanatory goal. The study was cross-sectional in nature. The data was collected via anonline questionnaire sent out to an online community consisting of around 20,000 members,which obtained 272 valid replies that passed the qualification question by purposive samplingThe data was tested using reliability testing, validity testing, and significance testing.Furthermore two simple linear regression analysis to test the two hypotheses formed in theconceptual framework.Findings:The findings of this paper states that LQS and LTS both show a significant positive impact onpurchase intention in an online context. LTS was shown to have a higher significant impacton purchase intention when comparing the two cues.Conclusion:The conclusion from this paper comes in three separate items. The general conclusion,theoretical implication and managerial implication. The general conclusion states that thefindings prove that LTS and LQS has a significant positive impact on purchase intention.Secondly, the theoretical implication states that LTS has a more significant impact onpurchase intention in an online context and that scarcity does not influence a positivebehavioural outcome such as purchase intention similarly offline versus online.The managerial implications state that LQS and LTS could be used to enhance purchaseintention synonymously with each other.

No description available.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The fast food industry, specifically the service department, has experienced sustainable economic growth and has evolved in the application of substantial methods, however, it has presented a slowdown due to deficient operation level provided in the customer service area. A large number of customers do not make the purchase owing to a series of unmet trends that face the consumer behaviour which leads to significant economic losses and inefficient service. They have therefore focused their efforts on finding impulse mechanisms through allowing them to migrate to less costly processes and/or to achieve better utilisation of available resources without success. This research inquires into the effectiveness of the Lean Thinking Simulation (LTS) model, which consists in the development of a set of methodological phases and the adaptation of the technological support termed as Digital Change to improve the performance of customer service in Peruvian fast food. The main result of this practical study was defined by a Dashboard in real-time, and as a first approximation of the model, a 17.03% improvement can be shown in the performance of customer service on the fast food selected. / Revisión por pares

Large, ever more complex, technological systems surround us and provide products and services that both construct and define much of what we consider as modern society. Our societal bargain is the trade-off between the benefits of our technologies and our constant vigilance over the safe workings and the occasional failures of these often hazardous sociotechnical systems during their operating life. Failure of a system's infrastructure, whether a complex subsystem or a single component, can cause planes to crash, oil rigs to burn, or the release of radioactivity from a nuclear power plant. To prevent catastrophes, much depends not only on skilled and safe operations, but upon the effective maintenance of these systems. Using the commercial nuclear power industry, of the United States, as a case study, this dissertation examines how nuclear power plant maintenance functions to ensure the plants are reliable and can safely operate for, potentially, eighty years; the current, government regulation defined limit, of their functional life. This study explores the history of U.S. nuclear maintenance regulatory policy from its early Cold War political precursors, the effect of the 1979 Three Mile Island reactor melt-down accident, through its long development, and finally its implementation by nuclear power licensees as formal maintenance programs. By investigating the maintenance of nuclear power plants this research also intends to expand the conceptual framework of large- technological-system (LTS) theory, in general, by adding a recognizable, and practically achievable, end-of-life (EOL) phase to the heuristic structure. The dissertation argues that maintenance is a knowledge producing technology that not only keeps a sociotechnical system operating through comprehension, but can be a surveillance instrument to make system end-of-life legible; that is both visible and understandable. With a discernible and legible view of system end-of-life, operators, policy makers, and the public can make more informed decisions concerning a system's safety and its continued usefulness in society. / Doctor of Philosophy / Large, ever more complicated, technical systems surround us and provide products and services that define much of what we consider as modern society. Our societal bargain is the trade-off between the benefits of our technologies and our constant vigilance over the safe workings and the occasional failures of these often hazardous systems during their operating life. Failure of a system's infrastructure, whether a complex subsystem or a single component, can cause planes to crash, oil rigs to burn, or the release of radioactivity from a nuclear power plant. To prevent catastrophes, much depends not only on skilled and safe operations, but upon the effective maintenance of these systems. Using the commercial nuclear power industry, of the United States, as a case study, this dissertation examines how nuclear power plant maintenance functions to ensure the plants are reliable and can safely operate for, potentially, eighty years; the current, government regulation defined limit, of their functional life. This study explores the history of U.S. nuclear maintenance regulatory policy from its early Cold War political precursors, the effect of the 1979 Three Mile Island reactor melt-down accident, through its long development, and finally its implementation by nuclear power licensees as formal maintenance programs. By investigating the maintenance of nuclear power plants this research also intends to develop a method to determine when a nuclear power plant, or other large technological system, is approaching or has reached the end of its reliable and safe operational life. The dissertation presents maintenance as a technology of knowledge that not only keeps a system operating through understanding of its components, but can be a general surveillance instrument to make system end-of- life legible. With a discernible and understandable view of end-of-life, operators, policy makers, and the public can make more informed decisions concerning a system's safety and its continued usefulness to society.