572 research outputs found

    A logic approach for exceptions and anomalies in association rules

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    Association rules have been used for obtaining information hidden in a database. Recent researches have pointed out that simple associations are insu cient for representing the diverse kinds of knowledge collected in a database. The use of exceptions and anomalies deal with a di erent type of knowledge sometimes more useful than simple associations. Moreover ex- ceptions and anomalies provide a more comprehensive understanding of the information provided by a database. This work intends to go deeper in the logic model studied in [5]. In the model, association rules can be viewed as general relations between two or more attributes quanti ed by means of a convenient quanti er. Using this formulation we establish the true semantics of the distinct kinds of knowledge we can nd in the database hidden in the four folds of the contingency table. The model is also useful for providing some measures for assessing the validity of those kinds of rulesPeer Reviewe

    Mining Linguistic Associations for Emergent Flood Prediction Adjustment

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    Floods belong to the most hazardous natural disasters and their disaster management heavily relies on precise forecasts. These forecasts are provided by physical models based on differential equations. However, these models do depend on unreliable inputs such as measurements or parameter estimations which causes undesirable inaccuracies. Thus, an appropriate data-mining analysis of the physical model and its precision based on features that determine distinct situations seems to be helpful in adjusting the physical model. An application of fuzzy GUHA method in flood peak prediction is presented. Measured water flow rate data from a system for flood predictions were used in order to mine fuzzy association rules expressed in natural language. The provided data was firstly extended by a generation of artificial variables (features). The resulting variables were later on translated into fuzzy GUHA tables with help of Evaluative Linguistic Expressions in order to mine associations. The found associations were interpreted as fuzzy IF-THEN rules and used jointly with the Perception-based Logical Deduction inference method to predict expected time shift of flow rate peaks forecasted by the given physical model. Results obtained from this adjusted model were statistically evaluated and the improvement in the forecasting accuracy was confirmed

    Islands in the grammar? Standards of evidence

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    When considering how a complex system operates, the observable behavior depends upon both architectural properties of the system and the principles governing its operation. As a simple example, the behavior of computer chess programs depends upon both the processing speed and resources of the computer and the programmed rules that determine how the computer selects its next move. Despite having very similar search techniques, a computer from the 1990s might make a move that its 1970s forerunner would overlook simply because it had more raw computational power. From the naïve observer’s perspective, however, it is not superficially evident if a particular move is dispreferred or overlooked because of computational limitations or the search strategy and decision algorithm. In the case of computers, evidence for the source of any particular behavior can ultimately be found by inspecting the code and tracking the decision process of the computer. But with the human mind, such options are not yet available. The preference for certain behaviors and the dispreference for others may theoretically follow from cognitive limitations or from task-related principles that preclude certain kinds of cognitive operations, or from some combination of the two. This uncertainty gives rise to the fundamental problem of finding evidence for one explanation over the other. Such a problem arises in the analysis of syntactic island effects – the focu

    The development of reasoning heuristics in autism and in typical development

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    Reasoning and judgment under uncertainty are often based on a limited number of simplifying heuristics rather than formal logic or rule-based argumentation. Heuristics are low-effort mental shortcuts, which save time and effort, and usually result in accurate judgment, but they can also lead to systematic errors and biases when applied inappropriately. In the past 40 years hundreds of papers have been published on the topic of heuristics and biases in judgment and decision making. However, we still know surprisingly little about the development and the cognitive underpinnings of heuristics and biases. The main aim of my thesis is to examine these questions. Another aim is to evaluate the applicability of dual-process theories of reasoning to the development of reasoning. Dual-process theories claim that there are two types of process underlying higher order reasoning: fast, automatic, and effortless (Type 1) processes (which are usually associated with the use of reasoning heuristics), and slow, conscious and effortful (Type 2) processes (which are usually associated with rule-based reasoning). This thesis presents eight experiments which investigated the development of reasoning heuristics in three different populations: typically developing children and adolescents between the age of 5 and 16, adolescents with autism, and university students. Although heuristic reasoning is supposed to be basic, simple, and effortless, we have found evidence that responses that are usually attributed to heuristic processes are positively correlated with cognitive capacity in the case of young children (even after controlling for the effects of age). Moreover, we have found that adolescents with autism are less susceptible to a number of reasoning heuristics than typically developing children. Finally, our experiments with university students provided evidence that education in statistics increases the likelihood of the inappropriate use of a certain heuristic (the equiprobability bias). These results offer a novel insight into the development of reasoning heuristics. Additionally, they have interesting implications for dual-process theories of reasoning, and they can also inform the debates about the rationality of reasoning heuristics and biases

    Measuring and assessing indeterminacy and variation in the morphology-syntax distinction (advance online)

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    We provide a discussion of some of the challenges in using statistical methods to investigate the morphology-syntax distinction cross-linguistically. The paper is structured around three problems related to the morphology-syntax distinction: (i) the boundary strength problem; (ii) the composition problem; (iii) the architectural problem. The boundary strength problem refers to the possibility that languages vary in terms of how distinct morphology and syntax are or the degree to which morphology is autonomous. The composition problem refers to the possibility that languages vary in terms of how they distinguish morphology and syntax: what types of properties distinguish the two systems. The architecture problem refers to the possibility that languages vary in terms of whether a global distinction between morphology and syntax is motivated at all and the possibility that languages might partition phenomena in different ways. This paper is concerned with providing an overarching review of the methodological problems involved in addressing these three issues. We illustrate the problems using three statistical methods: correlation matrices, random forests with different choices for the dependent variable, and hierarchical clustering with validation techniques

    Visual analytics for relationships in scientific data

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    Domain scientists hope to address grand scientific challenges by exploring the abundance of data generated and made available through modern high-throughput techniques. Typical scientific investigations can make use of novel visualization tools that enable dynamic formulation and fine-tuning of hypotheses to aid the process of evaluating sensitivity of key parameters. These general tools should be applicable to many disciplines: allowing biologists to develop an intuitive understanding of the structure of coexpression networks and discover genes that reside in critical positions of biological pathways, intelligence analysts to decompose social networks, and climate scientists to model extrapolate future climate conditions. By using a graph as a universal data representation of correlation, our novel visualization tool employs several techniques that when used in an integrated manner provide innovative analytical capabilities. Our tool integrates techniques such as graph layout, qualitative subgraph extraction through a novel 2D user interface, quantitative subgraph extraction using graph-theoretic algorithms or by querying an optimized B-tree, dynamic level-of-detail graph abstraction, and template-based fuzzy classification using neural networks. We demonstrate our system using real-world workflows from several large-scale studies. Parallel coordinates has proven to be a scalable visualization and navigation framework for multivariate data. However, when data with thousands of variables are at hand, we do not have a comprehensive solution to select the right set of variables and order them to uncover important or potentially insightful patterns. We present algorithms to rank axes based upon the importance of bivariate relationships among the variables and showcase the efficacy of the proposed system by demonstrating autonomous detection of patterns in a modern large-scale dataset of time-varying climate simulation

    Computer Science and Technology Series : XV Argentine Congress of Computer Science. Selected papers

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    CACIC'09 was the fifteenth Congress in the CACIC series. It was organized by the School of Engineering of the National University of Jujuy. The Congress included 9 Workshops with 130 accepted papers, 1 main Conference, 4 invited tutorials, different meetings related with Computer Science Education (Professors, PhD students, Curricula) and an International School with 5 courses. CACIC 2009 was organized following the traditional Congress format, with 9 Workshops covering a diversity of dimensions of Computer Science Research. Each topic was supervised by a committee of three chairs of different Universities. The call for papers attracted a total of 267 submissions. An average of 2.7 review reports were collected for each paper, for a grand total of 720 review reports that involved about 300 different reviewers. A total of 130 full papers were accepted and 20 of them were selected for this book.Red de Universidades con Carreras en Informática (RedUNCI

    Discovering logical knowledge in non-symbolic domains

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    Deep learning and symbolic artificial intelligence remain the two main paradigms in Artificial Intelligence (AI), each presenting their own strengths and weaknesses. Artificial agents should integrate both of these aspects of AI in order to show general intelligence and solve complex problems in real-world scenarios; similarly to how humans use both the analytical left side and the intuitive right side of their brain in their lives. However, one of the main obstacles hindering this integration is the Symbol Grounding Problem [144], which is the capacity to map physical world observations to a set of symbols. In this thesis, we combine symbolic reasoning and deep learning in order to better represent and reason with abstract knowledge. In particular, we focus on solving non-symbolic-state Reinforcement Learning environments using a symbolic logical domain. We consider different configurations: (i) unknown knowledge of both the symbol grounding function and the symbolic logical domain, (ii) unknown knowledge of the symbol grounding function and prior knowledge of the domain, (iii) imperfect knowledge of the symbols grounding function and unknown knowledge of the domain. We develop algorithms and neural network architectures that are general enough to be applied to different kinds of environments, which we test on both continuous-state control problems and image-based environments. Specifically, we develop two kinds of architectures: one for Markovian RL tasks and one for non-Markovian RL domains. The first is based on model-based RL and representation learning, and is inspired by the substantial prior work in state abstraction for RL [115]. The second is mainly based on recurrent neural networks and continuous relaxations of temporal logic domains. In particular, the first approach extracts a symbolic STRIPS-like abstraction for control problems. For the second approach, we explore connections between recurrent neural networks and finite state machines, and we define Visual Reward Machines, an extension to non-symbolic domains of Reward Machines [27], which are a popular approach to non-Markovian RL tasks
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