3,174 research outputs found

    Distributed Supervisory Control of Discrete-Event Systems with Communication Delay

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    This paper identifies a property of delay-robustness in distributed supervisory control of discrete-event systems (DES) with communication delays. In previous work a distributed supervisory control problem has been investigated on the assumption that inter-agent communications take place with negligible delay. From an applications viewpoint it is desirable to relax this constraint and identify communicating distributed controllers which are delay-robust, namely logically equivalent to their delay-free counterparts. For this we introduce inter-agent channels modeled as 2-state automata, compute the overall system behavior, and present an effective computational test for delay-robustness. From the test it typically results that the given delay-free distributed control is delay-robust with respect to certain communicated events, but not for all, thus distinguishing events which are not delay-critical from those that are. The approach is illustrated by a workcell model with three communicating agents

    Improving support services for rural schools : a management perspective

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    Management is a major weakness of rural school supervision systems. Management systems for rural schools should emphasize regular school visits by trained specialists whose task is to help rural teachers with teaching skills and rural principals with routine administrative tasks. The author points out that World Bank projects provide uncoordinated components, such as transportation and one time training efforts for field staff. The training and visit (T&V) system used in agricultural extension provides a model for managing supervision of rural education. It must be adapted to education by 1) targeting specific rural client groups with similar educational needs and problems, 2) providing services that schools want to receive, 3) strengthening links between teacher training colleges, educational research institutions, and rural classrooms. The author recommends including a T&V system in ongoing and future educational projects, after careful evaluation of the pilot project.Teaching and Learning,Gender and Education,Primary Education,ICT Policy and Strategies,Education Reform and Management

    Supervisory control of fuzzy discrete event systems with applications to mobile robotics

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    Fuzzy Discrete Event Systems (FDES) were proposed in the literature for modeling and control of a class of event driven and asynchronous dynamical systems that are affected by deterministic uncertainties and vagueness on their representations. In contrast to classical crisp Discrete Event Systems (DES), which have been explored to a sufficient extent in the past, an in-depth study of FDES is yet to be performed, and their feasible real-time application areas need to be further identified. This research work intends to address the supervisory control problem of FDES broadly, while formulating new knowledge in the area. Moreover, it examines the possible applications of these developments in the behavior-based mobile robotics domain. An FDES-based supervisory control framework to facilitate the behavior-based control of a mobile robot is developed at first. The proposed approach is modular in nature and supports behavior integration without making state explosion. Then, this architecture is implemented in simulation as well as in real-time on a mobile robot moving in unstructured environments, and the feasibility of the approach is validated. A general decentralized supervisory control theory of FDES is then established for better information association and ambiguity management in large-scale and distributed systems, while providing less complexity of control computation. Furthermore, using the proposed architecture, simulation and real-time experiments of a tightly-coupled multi-robot object manipulation task are performed. The results are compared with centralized FDES-based and decentralized DES-based approaches. -- A decentralized modular supervisory control theory of FDES is then established for complex systems having a number of modules that are concurrently operating and also containing multiple interactions. -- Finally, a hierarchical supervisory control theory of FDES is established to resolve the control complexity of a large-scale compound system by modularizing the system vertically and assigning multi-level supervisor hierarchies. As a proof-of-concept example to the established theory, a mobile robot navigation problem is discussed. This research work will contribute to the literature by developing novel knowledge and related theories in the areas of decentralized, modular and hierarchical supervisory control of FDES. It also investigates the applicability of these contributions in the mobile robotics arena

    Organizational choices of banks and the effective supervision of transnational financial institutions : [Version: 19 Juli 2012]

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    This paper outlines relatively easy to implement reforms for the supervision of transnational banking-groups in the E.U. that should not be primarily based on legal form but on the actual risk structures of the pertinent financial institutions. The proposal also aims at paying close attention to the economics of public administration and international relations in allocating competences among national and supranational supervisory bodies. Before detailing the own proposition, this paper looks into the relationship between sovereign debt and banking crises that drive regulatory reactions to the financial turmoil in the Euro area. These initiatives inter alia affirm effective prudential supervision as a pivotal element of crisis prevention. In order to arrive at a more informed idea, which determinants apart from a perceived appetite for regulatory arbitrage drive banksā€™ organizational choices, this paper scrutinizes the merits of either a branch or subsidiary structure for the cross-border business of financial institutions. In doing so, it also considers the policy-makers perspective. The analysis shows that no one size fits all organizational structure is available and concludes that banksā€™ choices should generally not be second-guessed, particularly because they are subject to (some) market discipline. The analysis proceeds with describing and evaluating how competences in prudential supervision are currently allocated among national and supranational supervisory authorities. In order to assess the findings the appraisal adopts insights form the economics of public administration and international relations. It argues that the supervisory architecture has to be more aligned with bureaucratsā€™ incentives and that inefficient requirements to cooperate and share information should be reduced. Contrary to a widespread perception, shifting responsibility to a supranational authority cannot solve all the problems identified. Resting on these foundations, the last part of this paper finally sketches an alternative solution that dwells on far-reaching mutual recognition of national supervisory regimes and allocates competences in line with supervisorsā€™ incentives and the risk inherent in crossborder banking groups

    Scientists, engineers and managers - Partners in space

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    Management practices in aerospace industr

    The Effects of Information Technology on Management and Organization.

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