161 research outputs found

    A conceptual model of personalized virtual learning environments

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    The Virtual Learning Environment (VLE) is one of the fastest growing areas in educational technology research and development. In order to achieve learning effectiveness, ideal VLEs should be able to identify learning needs and customize solutions, with or without an instructor to supplement instruction. They are called Personalized VLEs (PVLEs). In order to achieve PVLEs success, comprehensive conceptual models corresponding to PVLEs are essential. Such conceptual modeling development is important because it facilitates early detection and correction of system development errors. Therefore, in order to capture the PVLEs knowledge explicitly, this paper focuses on the development of conceptual models for PVLEs, including models of knowledge primitives in terms of learner, curriculum, and situational models, models of VLEs in general pedagogical bases, and particularly, the definition of the ontology of PVLEs on the constructivist pedagogical principle. Based on those comprehensive conceptual models, a prototyped multiagent-based PVLE has been implemented. A field experiment was conducted to investigate the learning achievements by comparing personalized and non-personalized systems. The result indicates that the PVLE we developed under our comprehensive ontology successfully provides significant learning achievements. These comprehensive models also provide a solid knowledge representation framework for PVLEs development practice, guiding the analysis, design, and development of PVLEs. (c) 2005 Elsevier Ltd. All rights reserved

    A probabilistic model of computing with words

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    AbstractComputing in the traditional sense involves inputs with strings of numbers and symbols rather than words, where words mean probability distributions over input alphabet, and are different from the words in classical formal languages and automata theory. In this paper our goal is to deal with probabilistic finite automata (PFAs), probabilistic Turing machines (PTMs), and probabilistic context-free grammars (PCFGs) by inputting strings of words (probability distributions). Specifically, (i) we verify that PFAs computing strings of words can be implemented by means of calculating strings of symbols (Theorem 1); (ii) we elaborate on PTMs with input strings of words, and particularly demonstrate by describing Example 2 that PTMs computing strings of words may not be directly performed through only computing strings of symbols, i.e., Theorem 1 may not hold for PTMs; (iii) we study PCFGs and thus PRGs with input strings of words, and prove that Theorem 1 does hold for PCFRs and PRGs (Theorem 2); a characterization of PRGs in terms of PFAs, and the equivalence between PCFGs and their Chomsky and Greibach normal forms, in the sense that the inputs are strings of words, are also presented. Finally, the main results obtained are summarized, and a number of related issues for further study are raised

    The Design of Agents Oriented Collaboration in SCM

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    In today\u27s global marketplace, individual firms no longer compete as independent entities but rather as integral part of supply chain links. In order to cater for the increasing demand on collaboration between supply chain partners, the technology of intelligent agent has gained increased interest in supply chain management. However fewer researches have clearly investigated the mechanism about agent applications in this area. In this paper we are to study the way how to incorporate intelligent agents into supply chain management from the perspective of agent-oriented system analysis and design. A multi-agent framework for collaborative planning, forecasting and replenishment in supply chain management is developed, in which supply chain collaboration models are composed from software components that represent types of supply chain agent, their constituent control elements, and their interaction protocols

    Knowledge Engineering in Agent Oriented Business Process Management

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    The challenge of dynamic environment requires managing business processes with the ability to adapt to changes and to collaborate in activities. As a promising technology to process management, agent technology with its flexible, distributed and intelligent features has been studied in numerous studies. However, most existing approaches are special and ad-hoc. They have not looked much into the nature and characteristic of agents and their rational behaviours in process management. This paper intends to investigate the mechanism how to build intelligent agents in dynamic process management from the view of knowledge engineering. An agent-oriented approach to dynamic process management with its knowledge engineering is discussed, and a three-layer knowledge model of intelligent agents is proposed. By exploiting the knowledge involved in dynamic process management and transforming it into a computational model, this work provides an essential support of developing agent-oriented approaches to business process management

    Stability of Random Forests and Coverage of Random-Forest Prediction Intervals

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    We establish stability of random forests under the mild condition that the squared response (Y2Y^2) does not have a heavy tail. In particular, our analysis holds for the practical version of random forests that is implemented in popular packages like \texttt{randomForest} in \texttt{R}. Empirical results show that stability may persist even beyond our assumption and hold for heavy-tailed Y2Y^2. Using the stability property, we prove a non-asymptotic lower bound for the coverage probability of prediction intervals constructed from the out-of-bag error of random forests. With another mild condition that is typically satisfied when YY is continuous, we also establish a complementary upper bound, which can be similarly established for the jackknife prediction interval constructed from an arbitrary stable algorithm. We also discuss the asymptotic coverage probability under assumptions weaker than those considered in previous literature. Our work implies that random forests, with its stability property, is an effective machine learning method that can provide not only satisfactory point prediction but also justified interval prediction at almost no extra computational cost.Comment: NeurIPS 202

    Intelligent Security System:Using Multi-Agent to Improve Internet Security

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    With the recent popularity of the Internet and the attendant proliferation of companies using it for all kinds of communication, a serious problem of security has arisen. In this paper, at first, current Internet security issues are addressed, and several existing technologies are discussed. Then we present an artificial intelligent solution which represents the current work of our Internet security project. Architecture, functions and features of the solution are described consequentl

    The dynamic predictive power of company comparative networks for stock sector performance

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    As economic integration and business connections increase, companies actively interact with each other in the market in cooperative or competitive relationships. To understand the market network structure with company relationships and to investigate the impacts of market network structure on stock sector performance, we propose the construct of a company comparative network based on public media data and sector interaction metrics based on the company network. All the market network structure metrics are integrated into a vector autoregression model with stock sector return and risk. Several findings demonstrate the dynamic relationships that exist between sector interactions and sector performance. First, sector interaction metrics constructed based on company networks are significant leading indicators of sector performance. Interestingly, the interactions between sectors have greater predictive power than those within sectors. Second, compared with the company closeness network, the company comparative network, which labels the cooperative or competitive relationships between companies, is a better construct to understand and predict sector interactions and performance. Third, competitive company interactions between sectors impact sector performance in a slower manner than cooperative company interactions. The findings enrich financial studies regarding asset pricing by providing additional explanations of company/sector interactions and insights into company management using industry-level strategies

    A Framework of Fuzzy Diagnosis

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    Fault diagnosis has become an important component in intelligent systems, such as intelligent control systems and intelligent eLearning systems. Reiter's diagnosis theory, described by first-order sentences, has been attracting much attention in this field. However, descriptions and observations of most real-world situations are related to fuzziness because of the incompleteness and the uncertainty of knowledge, e. g., the fault diagnosis of student behaviors in the eLearning processes. In this paper, an extension of Reiter's consistency-based diagnosis methodology, Fuzzy Diagnosis, has been proposed, which is able to deal with incomplete or fuzzy knowledge. A number of important properties of the Fuzzy diagnoses schemes have also been established. The computing of fuzzy diagnoses is mapped to solving a system of inequalities. Some special cases, abstracted from real-world situations, have been discussed. In particular, the fuzzy diagnosis problem, in which fuzzy observations are represented by clause-style fuzzy theories, has been presented and its solving method has also been given. A student fault diagnostic problem abstracted from a simplified real-world eLearning case is described to demonstrate the application of our diagnostic framework
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