913 resultados para Nested decisions


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DDM is a framework that combines intelligent agents and artificial intelligence traditional algorithms such as classifiers. The central idea of this project is to create a multi-agent system that allows to compare different views into a single one.

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The objective of the thesis is to structure and model the factors that contribute to and can be used in evaluating project success. The purpose of this thesis is to enhance the understanding of three research topics. The goal setting process, success evaluation and decision-making process are studied in the context of a project, business unitand its business environment. To achieve the objective three research questionsare posed. These are 1) how to set measurable project goals, 2) how to evaluateproject success and 3) how to affect project success with managerial decisions.The main theoretical contribution comes from deriving a synthesis of these research topics which have mostly been discussed apart from each other in prior research. The research strategy of the study has features from at least the constructive, nomothetical, and decision-oriented research approaches. This strategy guides the theoretical and empirical part of the study. Relevant concepts and a framework are composed on the basis of the prior research contributions within the problem area. A literature review is used to derive constructs of factors withinthe framework. They are related to project goal setting, success evaluation, and decision making. On the basis of this, the case study method is applied to complement the framework. The empirical data includes one product development program, three construction projects, as well as one organization development, hardware/software, and marketing project in their contexts. In two of the case studiesthe analytic hierarchy process is used to formulate a hierarchical model that returns a numerical evaluation of the degree of project success. It has its origin in the solution idea which in turn has its foundation in the notion of projectsuccess. The achieved results are condensed in the form of a process model thatintegrates project goal setting, success evaluation and decision making. The process of project goal setting is analysed as a part of an open system that includes a project, the business unit and its competitive environment. Four main constructs of factors are suggested. First, the project characteristics and requirements are clarified. The second and the third construct comprise the components of client/market segment attractiveness and sources of competitive advantage. Together they determine the competitive position of a business unit. Fourth, the relevant goals and the situation of a business unit are clarified to stress their contribution to the project goals. Empirical evidence is gained on the exploitation of increased knowledge and on the reaction to changes in the business environment during a project to ensure project success. The relevance of a successful project to a company or a business unit tends to increase the higher the reference level of project goals is set. However, normal performance or sometimes performance below this normal level is intentionally accepted. Success measures make project success quantifiable. There are result-oriented, process-oriented and resource-oriented success measures. The study also links result measurements to enablers that portray the key processes. The success measures can be classified into success domains determining the areas on which success is assessed. Empiricalevidence is gained on six success domains: strategy, project implementation, product, stakeholder relationships, learning situation and company functions. However, some project goals, like safety, can be assessed using success measures that belong to two success domains. For example a safety index is used for assessing occupational safety during a project, which is related to project implementation. Product safety requirements, in turn, are connected to the product characteristics and thus to the product-related success domain. Strategic success measures can be used to weave the project phases together. Empirical evidence on their static nature is gained. In order-oriented projects the project phases are oftencontractually divided into different suppliers or contractors. A project from the supplier's perspective can represent only a part of the ¿whole project¿ viewed from the client's perspective. Therefore static success measures are mostly used within the contractually agreed project scope and duration. Proof is also acquired on the dynamic use of operational success measures. They help to focus on the key issues during each project phase. Furthermore, it is shown that the original success domains and success measures, their weights and target values can change dynamically. New success measures can replace the old ones to correspond better with the emphasis of the particular project phase. This adjustment concentrates on the key decision milestones. As a conclusion, the study suggests a combination of static and dynamic success measures. Their linkage to an incentive system can make the project management proactive, enable fast feedback and enhancethe motivation of the personnel. It is argued that the sequence of effective decisions is closely linked to the dynamic control of project success. According to the used definition, effective decisions aim at adequate decision quality and decision implementation. The findings support that project managers construct and use a chain of key decision milestones to evaluate and affect success during aproject. These milestones can be seen as a part of the business processes. Different managers prioritise the key decision milestones to a varying degree. Divergent managerial perspectives, power, responsibilities and involvement during a project offer some explanation for this. Finally, the study introduces the use ofHard Gate and Soft Gate decision milestones. The managers may use the former milestones to provide decision support on result measurements and ad hoc critical conditions. In the latter milestones they may make intermediate success evaluation also on the basis of other types of success measures, like process and resource measures.

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While uncertainty abounds in almost any decision on investment in schooling, it is mostly ignored in research and virtually absent in labour economics tekst books. This paper documents the scope for risk, discusses the tough disentanglement of heterogeneity and risk, surveys the analytical models, laments the absence of a good workhorse model and points out the challenges worth tackling: document ex ante risk that investors face, develop a tractable and malleable analytical model and integrate the option of consumption smoothing in analytical and empirical work. Hedging labour market risk in the stock market can be safely ignored.

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BACKGROUND: Recent neuroimaging studies suggest that value-based decision-making may rely on mechanisms of evidence accumulation. However no studies have explicitly investigated the time when single decisions are taken based on such an accumulation process. NEW METHOD: Here, we outline a novel electroencephalography (EEG) decoding technique which is based on accumulating the probability of appearance of prototypical voltage topographies and can be used for predicting subjects' decisions. We use this approach for studying the time-course of single decisions, during a task where subjects were asked to compare reward vs. loss points for accepting or rejecting offers. RESULTS: We show that based on this new method, we can accurately decode decisions for the majority of the subjects. The typical time-period for accurate decoding was modulated by task difficulty on a trial-by-trial basis. Typical latencies of when decisions are made were detected at ∼500ms for 'easy' vs. ∼700ms for 'hard' decisions, well before subjects' response (∼340ms). Importantly, this decision time correlated with the drift rates of a diffusion model, evaluated independently at the behavioral level. COMPARISON WITH EXISTING METHOD(S): We compare the performance of our algorithm with logistic regression and support vector machine and show that we obtain significant results for a higher number of subjects than with these two approaches. We also carry out analyses at the average event-related potential level, for comparison with previous studies on decision-making. CONCLUSIONS: We present a novel approach for studying the timing of value-based decision-making, by accumulating patterns of topographic EEG activity at single-trial level.

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Social reciprocity may explain certain emerging psychological processes, which are likely to be founded on dyadic relations. Although some indices and statistics have been proposed to measure and make statistical decisions regarding social reciprocity in groups, these were generally developed to identify association patterns rather than to quantify the discrepancies between what each individual addresses to his/her partners and what is received from them in return. Additionally, social researchers are not only interested in measuring groups at the global level, since dyadic and individual measurements are also necessary for a proper description of social interactions. This study is concerned with a new statistic for measuring social reciprocity at the global level and with decomposing it in order to identify those dyads and individuals which account for a significant part of asymmetry in social interactions. In addition to a set of indices some exact analytical results are derived and a way of making statistical decisions is proposed.

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ABSTRACT The traditional method of net present value (NPV) to analyze the economic profitability of an investment (based on a deterministic approach) does not adequately represent the implicit risk associated with different but correlated input variables. Using a stochastic simulation approach for evaluating the profitability of blueberry (Vaccinium corymbosum L.) production in Chile, the objective of this study is to illustrate the complexity of including risk in economic feasibility analysis when the project is subject to several but correlated risks. The results of the simulation analysis suggest that the non-inclusion of the intratemporal correlation between input variables underestimate the risk associated with investment decisions. The methodological contribution of this study illustrates the complexity of the interrelationships between uncertain variables and their impact on the convenience of carrying out this type of business in Chile. The steps for the analysis of economic viability were: First, adjusted probability distributions for stochastic input variables (SIV) were simulated and validated. Second, the random values of SIV were used to calculate random values of variables such as production, revenues, costs, depreciation, taxes and net cash flows. Third, the complete stochastic model was simulated with 10,000 iterations using random values for SIV. This result gave information to estimate the probability distributions of the stochastic output variables (SOV) such as the net present value, internal rate of return, value at risk, average cost of production, contribution margin and return on capital. Fourth, the complete stochastic model simulation results were used to analyze alternative scenarios and provide the results to decision makers in the form of probabilities, probability distributions, and for the SOV probabilistic forecasts. The main conclusion shown that this project is a profitable alternative investment in fruit trees in Chile.

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We empirically contribute to the debate on business education in building on a decision frame perspective of decision making in corporate responsibility settings. Business schools have been accused to teach amoral theories, leading their students to behave less morally and engendering corporate responsibility scandals. Research has also pointed toward self-selection: business students would differ from non-business students before entering business school. We examine the role of socioeconomic status, core self-evaluations in this regard. Further, we investigate the belief in a free market as a distal influence triggering a business frame, and moral intensity as a proximal influence triggering a moral frame on responsible decision making by business and non-business students. Cross-sectional data obtained from 566 students on two decision making scenarios mostly supported our hypotheses. Socioeconomic status but not core self-evaluations explain the belief in a free market, and had indirect effects on the likelihood to make a less responsible decision. Importantly, the relationship between business studies and the belief in a free market remained significant after accounting for these variables. Our study thus contributes to the socialization and self-selection arguments. We discuss theoretical and practical implications for research on decision frames and for business education, respectively.

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Population ageing brings new challenges to long-term household economic decisions. In the event of old-age dependency, housing assets become a key self-insurance device. However, little empirical evidence has been reported regarding an individual"s expectations of having to use their housing wealth for such a purpose. This paper draws upon two complementary data sources to empirically examine: (1) the influence of housing assets on an individual"s willingness-to-sell (WTS) their dwelling for care purposes, and (2) the willingness to take out a reverse mortgage contract loan in the event of old-age dependency. The paper"s findings suggest that homeowners" WTS in old age is unaffected by their income or housing assets and is, rather, determined by socio-environmental housing characteristics and the individual"s health and personal needs. Conversely, the study finds that the uptake of home reversion loans is largely dependent on income or education, but not on a household"s housing assets.

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OBJECTIVE: It has been suggested that Schistosoma mansoni, which is endemic in African fishing communities, might increase susceptibility to human immunodeficiency virus (HIV) acquisition. If confirmed, this would be of great public health importance in these high HIV-risk communities. This study was undertaken to determine whether S. mansoni infection is a risk factor for HIV infection among the fishing communities of Lake Victoria, Uganda. We conducted a matched case-control study, nested within a prospective HIV incidence cohort, including 50 HIV seroconverters (cases) and 150 controls during 2009-2011. METHODS: S. mansoni infection prior to HIV seroconversion was determined by measuring serum circulating anodic antigen (CAA) in stored serum. HIV testing was carried out using the Determine rapid test and infection confirmed by enzyme-linked immunosorbent assays. RESULTS: About 49% of cases and 52% of controls had S. mansoni infection prior to HIV seroconversion (or at the time of a similar study visit, for controls): odds ratio, adjusting for ethnicity, religion, marital status, education, occupation, frequency of alcohol consumption in previous 3 months, number of sexual partners while drunk, duration of stay in the community, and history of schistosomiasis treatment in the past 2 years was 1.23 (95% CI 0.3-5.7) P = 0.79. S. mansoni infections were chronic (with little change in status between enrolment and HIV seroconversion), and there was no difference in median CAA concentration between cases and controls. CONCLUSIONS: These results do not support the hypothesis that S. mansoni infection promotes HIV acquisition.

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'Què faries si l"única manera de salvar cinc persones d"una mort segura a causa d"un accident atzarós fos provocar expressament la mort d"una altra persona que no està en perill?" No és una pregunta fàcil, ni la resposta trivial. Prenem decisions constantment, sovint intranscendents-quina camisa em poso avui?-, però també moltes que tenen un cert component moral, que poden afectar altres persones.

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Diferents estudis mostren que les persones que parlen dues llengües són més àgils a l"hora de resoldre conflictes en què cal valorar diferents informacions de manera simultània

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A growing body of scientific literature recurrently indicates that crime and forensic intelligence influence how crime scene investigators make decisions in their practices. This study scrutinises further this intelligence-led crime scene examination view. It analyses results obtained from two questionnaires. Data have been collected from nine chiefs of Intelligence Units (IUs) and 73 Crime Scene Examiners (CSEs) working in forensic science units (FSUs) in the French speaking part of Switzerland (six cantonal police agencies). Four salient elements emerged: (1) the actual existence of communication channels between IUs and FSUs across the police agencies under consideration; (2) most CSEs take into account crime intelligence disseminated; (3) a differentiated, but significant use by CSEs in their daily practice of this kind of intelligence; (4) a probable deep influence of this kind of intelligence on the most concerned CSEs, specially in the selection of the type of material/trace to detect, collect, analyse and exploit. These results contribute to decipher the subtle dialectic articulating crime intelligence and crime scene investigation, and to express further the polymorph role of CSEs, beyond their most recognised input to the justice system. Indeed, they appear to be central, but implicit, stakeholders in intelligence-led style of policing.

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En entreprise, les supérieurs hiérarchiques ont une influence non négligeable sur la prise de décision de leurs subordonnés. Ces derniers tendent à se conformer à l'avis de leur supérieur pour prendre leurs décisions. Toutefois, cette conformité des subordonnés à l'avis de leur supérieur peut devenir un problème lorsque l'avis reçu est questionnable d'un point de vue éthique. Les études antérieures menées à ce sujet ont démontré que le contenu n'a pas d'impact, c'est-à-dire que du moment qu'un avis est donné par un supérieur hiérarchique, les subordonnés tendent à se conformer à cet avis quelque soit son contenu. Dans la présente expérience, nous nous sommes intéressés à ce phénomène de conformité dans une prise de décision ayant des conséquences sur des personnes. En particulier, nous avons étudié le rôle de l'empathie, définit comme l'habilité de ressentir les émotions des autres ou de se mettre à leur place. Notre première hypothèse concerne l'effet principal de l'avis du supérieur : les participants tiennent compte de l'avis de leur supérieur dans leur prise de décision. Notre seconde hypothèse concerne le rôle modérateur de l'empathie: les participants haut en empathie sont moins sensibles à l'avis de leur supérieur que les participants bas en empathie étant donné qu'ils anticipent les conséquences de leur décision vis-à-vis des personnes concernées. Cent-douze étudiants ont participé à un exercice de mise en situation. Dans la peau d'un chef de Département d'une entreprise, ils devaient entre autres réfléchir au problème du niveau des salaires du personnel peu qualifié et en particulier au fait que cette catégorie de salariés était surpayée par rapport à ce qui se pratiquait sur le marché du travail. Cette expérience était composée de deux conditions, où l'avis du supérieur était manipulé. Dans la condition 1, l'avis du supérieur était de baisser les salaires, alors que dans la condition 2 l'avis était de garder les salaires constants. Les résultats ont confirmé nos hypothèses. Les participants recevant l'avis de leur supérieur de baisser les salaires ont effectivement pris la décision de baisser les salaires. Il a aussi été démontré que le niveau d'empathie modère cette relation. Les participants haut en empathie ont eu tendance à ne pas suivre l'avis donné contrairement aux participants bas en empathie. Cela démontre ainsi l'influence que peut avoir le contexte sur les individus et leur prise de décision mais aussi que les caractéristiques personnelles ont une influence non négligeable.

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HIV-infected women are at increased risk of cervical intraepithelial neoplasia (CIN) and invasive cervical cancer (ICC), but it has been difficult to disentangle the influences of heavy exposure to HPV infection, inadequate screening and immunodeficiency. A case-control study including 364 CIN2/3 and 20 ICC cases matched to 1,147 controls was nested in the Swiss HIV Cohort Study (1985-2013). CIN2/3 risk was significantly associated with low CD4+ cell counts, whether measured as nadir [odds ratio (OR) per 100-cell/μL decrease = 1.15, 95% CI: 1.08, 1.22], or at CIN2/3 diagnosis (1.10, 95% CI: 1.04, 1.16). An association was evident even for nadir CD4+ 200-349 versus ≥350 cells/μL (OR = 1.57, 95% CI: 1.09, 2.25). After adjustment for nadir CD4+, a protective effect of >2-year cART use was seen against CIN2/3 (OR versus never cART use = 0.64, 95% CI: 0.42, 0.98). Despite low study power, similar associations were seen for ICC, notably with nadir CD4+ (OR for 50 vs. >350 cells/μL= 11.10, 95% CI: 1.24, 100). HPV16-L1 antibodies were significantly associated with CIN2/3, but HPV16-E6 antibodies were nearly exclusively detected in ICC. In conclusion, worsening immunodeficiency, even at only moderately decreased CD4+ cell counts, is a significant risk factor for CIN2/3 and cervical cancer.