2,418 research outputs found

    Adaptive fuzzy interpolation

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    Fuzzy interpolative reasoning strengthens the power of fuzzy inference by the enhancement of the robustness of fuzzy systems and the reduction of the systems' complexity. However, after a series of interpolations, it is possible that multiple object values for a common variable are inferred, leading to inconsistency in interpolated results. Such inconsistencies may result from defective interpolated rules or incorrect interpolative transformations. This paper presents a novel approach for identification and correction of defective rules in interpolative transformations, thereby removing the inconsistencies. In particular, an assumption-based truth-maintenance system (ATMS) is used to record dependences between interpolations, and the underlying technique that the classical general diagnostic engine (GDE) employs for fault localization is adapted to isolate possible faulty interpolated rules and their associated interpolative transformations. From this, an algorithm is introduced to allow for the modification of the original linear interpolation to become first-order piecewise linear. The approach is applied to a realistic problem, which predicates the diarrheal disease rates in remote villages, to demonstrate the potential of this study

    Proceedings of the first international VLDB workshop on Management of Uncertain Data

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    Interactions between perception and rule-construction in human and machine concept learning

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    Weitnauer E. Interactions between perception and rule-construction in human and machine concept learning. Bielefeld: Universität Bielefeld; 2016.Concepts are central to human cognition and one important type of concepts can be represented naturally with symbolic rules. The learning of such rule-based concepts from examples relies both on a process of perception, which extracts information from the presented examples, and a process of concept construction, which leads to a rule that matches the given examples and can be applied to categorize new ones. This thesis introduces PATHS, a novel cognitive process model that learns structured, rule-based concepts and takes the active and explorative nature of perception into account. In contrast to existing models, the PATHS model tightly integrates perception and rule construction. The model is applied to a challenging problem domain, the physical Bongard problems, and its performance under different learning conditions is analyzed and compared to that of human solvers

    The political economy of unemployment, labour market institutions and macroeconomic policies in open economies: the cases of Germany and the Netherlands in the 1980s and 1990s

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    The question that this thesis addresses is how western European countries with regulated labour markets managed to reduce their unemployment rates in the 1980s and 1990s. Most of the accounts in mainstream economics literature have been trying to explain this turnaround in performance in terms of labour market reforms that were undertaken in the direction of deregulation and by stressing potential interactions between such reforms in labour market policies, backing their claims with econometric evidence that is usually not robust. This thesis takes a different approach both theoretically and empirically. Theoretically, it develops the hypothesis that in open economies, coordinated collective wage bargaining can lead to moderate wage/price outcomes in the presence of conservative/stability oriented macroeconomic policies even in the presence of generous labour market protection policies. Moreover, in countries with regulated labour markets, the effectiveness of moderate bargaining outcomes and labour market reforms in combating unemployment will depend on the size and openness of the economy: the smaller and more open an economy is, the more effective moderate bargaining outcomes and labour market reforms will be in reducing the equilibrium rate of unemployment. This hypothesis is an alternative to the ‘deregulation thesis’ rather than a competing one. This hypothesis is explored and further qualified in this thesis through qualitative comparative analysis-QCA with fuzzy-sets and the detailed study of the cases of the Netherlands and Germany in the 1980s and the 1990s. The upshot of the analysis of this thesis is that the effects of labour market policies and institutions on labour market performance should be considered within the context of macro-level institutions (e.g. macroeconomic policies) and characteristics (e.g. openness to trade) if we want to accurately assess the need to reform them

    Attribute Weighted Fuzzy Interpolative Reasoning

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    Africa in Transition -- Nexus Between State Building & Regional Integration

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    Regional integration in Africa is at a nascent stage, despite long-standing interest in continental unification since the Pan-African independence movements. The current surge in continental-wide economic integration builds on previous efforts, yet is markedly different in terms of the ideas, interests, and institutions today. A primary reason for the failure of the first East Africa attempt to integrate was the lack of a strong private sector. Research on African regionalism has focused mostly on limited success, lack of economic growth, and persistent wide-spread poverty. Recent developments present an opportunity to objectively study the gradual evolution in African perspectives and state capacities. This dissertation employs a neo-institutional theoretical construct within a temporal frame to examine factors motivating states to attempt the complicated and potentially risky process of economic competition. Using a fuzzy-set Qualitative Comparative Analysis (fsQCA) followed by process-tracing case studies, this research analyzes variables impacting elite bargaining and decision-making. Results demonstrate that conjunctions of certain conditions are at work in creating cooperative institutions, specifically economic pressures, regional insecurity, plus state capacity. These conditions have influenced the evolution of states’ perceptions regarding the potential for integration to maximize states’ welfare as well as national ability to navigate the process. The temporal dimension reveals a change in the relationship between government and business elites is a significant departure from the failed East African attempt in the 1960s. Gradual convergence in national preferences, combined with exogenous support for integration are subtle but measurable. The argument made here is not that regional integration will be successful or that conditions will not change in the future. Rather, this study focuses on the gradual evolution in underlying dynamics influencing changing relations, namely the strengthening interaction between government policymakers and economic powerbrokers. Today, business pressure groups have a vested interest in regional trade and, consequently, an influential role in international politics as theorized by neo-institutionalism. Empirical evidence demonstrates interest in interdependence can drive support for creation of mechanisms conducive to economic integration. Mutually reinforcing forces resulted in observable state direction of resources to enhance economic competitiveness, human capital, and regional security via cooperative regional programs and institutions
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