824 resultados para Probabilistic decision process model


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An analysis of diabatic heating and moistening processes from 12-36 hour lead time forecasts from 12 Global Circulation Models are presented as part of the "Vertical structure and physical processes of the Madden-Julian Oscillation (MJO)" project. A lead time of 12-36 hours is chosen to constrain the large scale dynamics and thermodynamics to be close to observations while avoiding being too close to the initial spin-up for the models as they adjust to being driven from the YOTC analysis. A comparison of the vertical velocity and rainfall with the observations and YOTC analysis suggests that the phases of convection associated with the MJO are constrained in most models at this lead time although the rainfall in the suppressed phase is typically overestimated. Although the large scale dynamics is reasonably constrained, moistening and heating profiles have large inter-model spread. In particular, there are large spreads in convective heating and moistening at mid-levels during the transition to active convection. Radiative heating and cloud parameters have the largest relative spread across models at upper levels during the active phase. A detailed analysis of time step behaviour shows that some models show strong intermittency in rainfall and differences in the precipitation and dynamics relationship between models. The wealth of model outputs archived during this project is a very valuable resource for model developers beyond the study of the MJO. In addition, the findings of this study can inform the design of process model experiments, and inform the priorities for field experiments and future observing systems.

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Understanding farmer behaviour is needed for local agricultural systems to produce food sustainably while facing multiple pressures. We synthesize existing literature to identify three fundamental questions that correspond to three distinct areas of knowledge necessary to understand farmer behaviour: 1) decision-making model; 2) cross-scale and cross-level pressures; and 3) temporal dynamics. We use this framework to compare five interdisciplinary case studies of agricultural systems in distinct geographical contexts across the globe. We find that these three areas of knowledge are important to understanding farmer behaviour, and can be used to guide the interdisciplinary design and interpretation of studies in the future. Most importantly, we find that these three areas need to be addressed simultaneously in order to understand farmer behaviour. We also identify three methodological challenges hindering this understanding: the suitability of theoretical frameworks, the trade-offs among methods and the limited timeframe of typical research projects. We propose that a triangulation research strategy that makes use of mixed methods, or collaborations between researchers across mixed disciplines, can be used to successfully address all three areas simultaneously and show how this has been achieved in the case studies. The framework facilitates interdisciplinary research on farmer behaviour by opening up spaces of structured dialogue on assumptions, research questions and methods employed in investigation.

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Background: Concerted evolution is normally used to describe parallel changes at different sites in a genome, but it is also observed in languages where a specific phoneme changes to the same other phoneme in many words in the lexicon—a phenomenon known as regular sound change. We develop a general statistical model that can detect concerted changes in aligned sequence data and apply it to study regular sound changes in the Turkic language family. Results: Linguistic evolution, unlike the genetic substitutional process, is dominated by events of concerted evolutionary change. Our model identified more than 70 historical events of regular sound change that occurred throughout the evolution of the Turkic language family, while simultaneously inferring a dated phylogenetic tree. Including regular sound changes yielded an approximately 4-fold improvement in the characterization of linguistic change over a simpler model of sporadic change, improved phylogenetic inference, and returned more reliable and plausible dates for events on the phylogenies. The historical timings of the concerted changes closely follow a Poisson process model, and the sound transition networks derived from our model mirror linguistic expectations. Conclusions: We demonstrate that a model with no prior knowledge of complex concerted or regular changes can nevertheless infer the historical timings and genealogical placements of events of concerted change from the signals left in contemporary data. Our model can be applied wherever discrete elements—such as genes, words, cultural trends, technologies, or morphological traits—can change in parallel within an organism or other evolving group.

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Research on invention has focused on business invention and little work has been conducted on the process and capability required for the individual inventor or the capabilities required for an advice to be considered an invention. This paper synthesises the results of an empirical survey of ten inventor case studies with current research on invention and recent capability affordance research to develop an integrated capability process model of human capabilities for invention and specific capabilities of an invented device. We identify eight necessary human effectivities required for individual invention capability and six functional key activities using these effectivities, to deliver the functional capability of invention. We also identified key differences between invention and general problem solving processes. Results suggest that inventive step capability relies on a unique application of principles that relate to a new combination of affordance chain with a new mechanism and or space time (affordance) path representing the novel way the device works, in conjunction with defined critical affordance operating factors that are the subject of the patent claims.

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We utilized an ecosystem process model (SIPNET, simplified photosynthesis and evapotranspiration model) to estimate carbon fluxes of gross primary productivity and total ecosystem respiration of a high-elevation coniferous forest. The data assimilation routine incorporated aggregated twice-daily measurements of the net ecosystem exchange of CO2 (NEE) and satellite-based reflectance measurements of the fraction of absorbed photosynthetically active radiation (fAPAR) on an eight-day timescale. From these data we conducted a data assimilation experiment with fifteen different combinations of available data using twice-daily NEE, aggregated annual NEE, eight-day f AP AR, and average annual fAPAR. Model parameters were conditioned on three years of NEE and fAPAR data and results were evaluated to determine the information content from the different combinations of data streams. Across the data assimilation experiments conducted, model selection metrics such as the Bayesian Information Criterion and Deviance Information Criterion obtained minimum values when assimilating average annual fAPAR and twice-daily NEE data. Application of wavelet coherence analyses showed higher correlations between measured and modeled fAPAR on longer timescales ranging from 9 to 12 months. There were strong correlations between measured and modeled NEE (R2, coefficient of determination, 0.86), but correlations between measured and modeled eight-day fAPAR were quite poor (R2 = −0.94). We conclude that this inability to determine fAPAR on eight-day timescale would improve with the considerations of the radiative transfer through the plant canopy. Modeled fluxes when assimilating average annual fAPAR and annual NEE were comparable to corresponding results when assimilating twice-daily NEE, albeit at a greater uncertainty. Our results support the conclusion that for this coniferous forest twice-daily NEE data are a critical measurement stream for the data assimilation. The results from this modeling exercise indicate that for this coniferous forest, average annuals for satellite-based fAPAR measurements paired with annual NEE estimates may provide spatial detail to components of ecosystem carbon fluxes in proximity of eddy covariance towers. Inclusion of other independent data streams in the assimilation will also reduce uncertainty on modeled values.

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Observed and predicted changes in the strength of the westerly winds blowing over the Southern Ocean have motivated a number of studies of the response of the Antarctic Circumpolar Current and Southern Ocean Meridional Overturning Circulation (MOC) to wind perturbations and led to the discovery of the``eddy-compensation" regime, wherein the MOC becomes insensitive to wind changes. In addition to the MOC, tracer transport also depends on mixing processes. Here we show, in a high-resolution process model, that isopycnal mixing by mesoscale eddies is strongly dependent on the wind strength. This dependence can be explained by mixing-length theory and is driven by increases in eddy kinetic energy; the mixing length does not change strongly in our simulation. Simulation of a passive ventilation tracer (analogous to CFCs or anthropogenic CO$_2$) demonstrates that variations in tracer uptake across experiments are dominated by changes in isopycnal mixing, rather than changes in the MOC. We argue that, to properly understand tracer uptake under different wind-forcing scenarios, the sensitivity of isopycnal mixing to winds must be accounted for.

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This paper presents an integrative and spatially explicit modeling approach for analyzing human and environmental exposure from pesticide application of smallholders in the potato producing Andean region in Colombia. The modeling approach fulfills the following criteria: (i) it includes environmental and human compartments; (ii) it contains a behavioral decision-making model for estimating the effect of policies on pesticide flows to humans and the environment; (iii) it is spatially explicit; and (iv) it is modular and easily expandable to include additional modules, crops or technologies. The model was calibrated and validated for the Vereda La Hoya and was used to explore the effect of different policy measures in the region. The model has moderate data requirements and can be adapted relatively easy to other regions in developing countries with similar conditions.

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In this work we construct the stationary measure of the N species totally asymmetric simple exclusion process in a matrix product formulation. We make the connection between the matrix product formulation and the queueing theory picture of Ferrari and Martin. In particular, in the standard representation, the matrices act on the space of queue lengths. For N > 2 the matrices in fact become tensor products of elements of quadratic algebras. This enables us to give a purely algebraic proof of the stationary measure which we present for N=3.

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The aim of the project is to develop a tool for a management system at the advertising agency ofConfetti. The company has during a longer period of time felt a need of introducing a quality and environmentalsystem but have a lack in resources of knowledge, time and money. Their goal is to have aconcrete documentation which describes their quality policy and the function of the activity.The work has been performed by mapping and analyzing the processes of the company according tothe process model with focus on one pilot process. New routines have been developed and documentedin a management system.Confetti would like their management system to fulfil the ISO-standard so that they eventually inthe future can be certified. Therefore a literature study has been done according to management systemsand standards. The project has been directed to fulfil the ISO-standards demands for a qualitymanagement system. It has resulted in the creation of a comprehensible and userfriendly managementsystem which includes a routine model and new routines for the pilot process of PDF-handling. A oneyear-plan has been created to facilitate for the continuos development of the quality management systemat Confetti. The new quality implementations demands investment, why a budget has been calculatedshowing profitability.Confetti has to continue the development of the management system very soon. They ought to createan analyzis of the companys current situation and choose the processes that they themeselves considermost important or easiest to improve. A management system will not operate by it self, it needsmaintenance and development.

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Forskningen visar att förändringar av informationsteknologin och en ökande anskaffning av nya programvaror har lett till underliggande problem som kan drabba heterogena programvarulicensmiljöer och stora organisationer. Underliggande problem i den stora kontexten är mjukvaruhantering. Licenshantering av programvaror är just en förgrening av det stora problemet. Stora organisationer som en kommunal verksamhet är drabbad av det här underliggande problemet på grund av komplexitet hos organisationens miljö. Att tillämpa förändringar i området programvarulicens är omöjligt utan att göra förändringar i hela den organisationsprocess som följer med det. Fallstudiens uppdrag är ett nytt omfattande område kring licenshantering av programvaror som kan vara väldigt lärorikt och en bra erfarenhet att ta del av. Uppsatsen beskriver hur en kommunal verksamhets licenshantering av programvaror ser ut och de problem som finns med den nuvarande licenshanteringsprocessen. Förarbetet med en litteraturstudie tillsammans med datagenereringsmetoderna intervjuer, dokumentstudier och observationer används för att studera fallet på djupet. Målet är att kunna ta fram de nuvarande problem som finns, analysera dem och ge rekommendation för åtgärder som det studerade fallobjektet, Falu Kommuns IT-kontor, kan använda. En rekommendation för en tydlig licenshanteringsprocessmodell anses vara ett bra akademiskt bidrag eftersom problemet med licenshanteringen av programvaror är ett generellt problem. Uppsatsens resultat är en processmodell om licenshantering av programvaror för organisationer med IT-tjänstkunder. Det är en generisk lösning som skulle kunna användas av andra kommunverksamheter och liknande organisationer.

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It is an everyday experience to realize that things do not turn out the as expected. But what if you realize that everything you have so far experienced as reality is illusion? This article is about former members of the Jehovah’s Witnesses who have had doubts about what they previously believed to be the Truth. The article also treats the exit process, from being a Jehovah’s Witness to becoming an ex-Jehovah’s Witness. The data consists of twenty qualitative interviews with ten Jehovah’s Witnesses and twenty qualitative interviews with ten former Jehovah’s Witnesses. The data also include a diary written during four years preceding an exit from the organization. The analysis was made through thematic concentration. Ontologically the analysis and the article are based on a constructionist view though it is mainly empirical with no further theoretical assessment. However, to be able to understand the results a contextual frame is sketched with two factors affecting members who make an exit. First there are tying factors that bind the person closer to the organization; these are closeness and friendship and confirmation. A secluding factor is something that secludes the member from the outside society; these factors are the work situation and »closed doors«. With high values on these factors the exit process will be more arduous. The results are presented through a process model in which different phases or steps in the exit process are described. The following steps in the process are: (1) different levels of doubts; (2) trying out doubts; (3) turning points; (4) different decisions; (5) different steps in execution; (6) floating; (7) relative neutrality. The process is defined as an altogether ambivalent and emotionally tough experience, but other parts of life may be affected as well, such as employment, social life, family life and career.

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Neste projeto busca-se identificar as reações dos consumidores brasileiros ao recall de produtos. No exterior recall é prática mais antiga enquanto que no Brasil é um procedimento recente, mas que vem ganhando crescente importância nos últimos anos. De fato, esse alerta, que um determinado lote da produção não saiu de fábrica como o planejado, feito pelos fabricantes a um grupo de compradores de seus produtos, vem ocorrendo com mais freqüência e particularmente no setor automobilístico. Todavia, é bem possível que muitos consumidores ainda não conheçam esse procedimento e nem saibam que estão sujeitos a imprevistos como o de adquirir um produto que, mesmo tendo passado pelos testes de qualidade do fabricante, possa estar sendo objeto de um chamado desse tipo, pois algo diferente do que era esperado foi encontrado no produto: ele não passou por alguma sabatina posterior de testes do fabricante ou até mesmo de sua matriz no exterior! O objetivo do estudo é o de identificar as reações do consumidor frente ao recall de produtos e os impactos que possa estar criando para ele.

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Esta pesquisa analisa a difusão das certificações ISO-9000 no Brasil sob o prisma da teoria neo-institucional e de referências sobre modismos gerenciais nas organizações. A premissa é de que muitas dessas decisões de certificação - que se tornou muito popular nas empresas brasileiras desde 1990 - só podem ser entendidas plenamente à luz de sua natureza modal e institucionalizada, e que muitas desses processos podem refletir adoções cerimoniais (isto é "para inglês ver"). Através de questionários aplicados em empresas que buscaram a certificação ISO no Brasil, o estudo procura entender melhor fatores ligados à tomada de decisão sobre a adoção, à estratégia de implantação, aos resultados percebidos e aos mecanismos de justificação dos programas.

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Este trabalho pretende analisar os principais centros de pós-graduação e de pesquisa em economia localizados em São Paulo e no Rio de Janeiro, a partir do levantamento de documentos, programas, regulamentos e publicações de seus principais expoentes. Também pretendemos utilizar depoimentos desses expoentes para entender como os processos decisórios foram analisados de "dentro" da instituição. A história da vida do entrevistado permite que entremos no mundo das emoções, nos limites da racionalidade do ator histórico. Ao quebrarmos o esquematismo simplista, podemos desvendar as relações entre o indivíduo e a rede histórica. A memória, com suas falhas, distorções e inversões, torna-se um elemento de análise para explicar o presente, a partir da compreensão do passado sob a ótica de quem vivenciou os fatos.

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Esta pesquisa investiga as relações, nem sempre claras e explícitas, entre competitividade e inovação tecnológica, iniciando pelo referencial teórico. São estudados quatro casos de empresas, sendo três delas brasileiras e uma multinacional, dos setores de indústria e serviços. Dentre as conclusões, destaca-se a constatação de que a competitividade resulta da combinação de três dimensões: tecnologia, gestão (isto é, estratégia de negócio) e pessoas. Também se identificou uma íntima ligação entre inovação tecnológica e ganhos de market share. O estudo demonstra ainda que ganhos de competitividade com base tecnológica, ainda que significativos, são efêmeros, ou seja: a manutenção da vantagem competitiva é um processo dinâmico que exige permanentes esforços de inovação, inclusive com monitoramento constante do mercado e da concorrência. Outro aspecto investigado é o risco inerente à inovação, uma vez que o pioneirismo nem sempre encontra, de imediato, as soluções que se firmam como padrão no mercado. Finalmente, discorre-se também sobre o processo de decisão quanto a investimentos em tecnologia, apresentando modelos não quantitativos como auxiliares na análise e priorização de projetos inovadores.