2,548 research outputs found

    A proposal of an architecture for the coordination level of intelligent machines

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    The issue of obtaining a practical, structured, and detailed description of an architecture for the Coordination Level of Center for Intelligent Robotic Systems for Sapce Exploration (CIRSSE) Testbed Intelligent Controller is addressed. Previous theoretical and implementation works were the departure point for the discussion. The document is organized as follows: after this introductory section, section 2 summarizes the overall view of the Intelligent Machine (IM) as a control system, proposing a performance measure on which to base its design. Section 3 addresses with some detail implementation issues. An hierarchic petri-net with feedback-based learning capabilities is proposed. Finally, section 4 is an attempt to address the feedback problem. Feedback is used for two functions: error recovery and reinforcement learning of the correct translations for the petri-net transitions

    Simulating Train Dispatching Logic with High-Level Petri Nets

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    Railway simulation is commonly used as a tool for planning and analysis of railway traffic in operational, tactical and strategical level. During the simulation, a typical problem is a deadlock, i.e. a specific composition of trains on a simulated section positioned in such a way that they are blocking each other\u27s paths. Deadlock avoidance is very important in the simulation of railways because deadlock can stop the simulation, and significantly affect the simulation results. Simulation of train movements on a single track line requires implantation of additional rules and principles of train spacing and movement as train paths are more often in conflict than on a double track line. A High-level Petri Nets simulation model that detects and manages train path conflicts on a single track railway line is presented. Module for train management is connected to other modules on a hierarchical High-level Petri net. The model was tested on a busy single track mainline between Hrpelje-Kozina and Koper in south-western Slovenia

    Network Supplier Credit Management: Models Based on Petri Net

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    In current credit evaluation methods, the credit condition of the network supplier and the credit degree of each index cannot be described well, and the credit evaluation data only source of the transaction platform have much limitation. This research proposes the method of calculating the importance and the value of the credit evaluation indexes, and proposes to put credit evaluation into big data environment. This research uses the transaction process of B2C as the case, and constructs multiple attribute weighted Petri net credit index subnet (CWPSN) for realizing the credit evaluation of the network supplier, and for presenting the correlations among the evaluation results of the credit evaluation indexes, and for presenting the importance of the indexes and the credit degree of each index, and describes the cost optimization process with credit cost optimization investment process Petri net (CCOIPPN). By the case to verify the credit evaluation method based on Petri net and the cost optimization method based on Petri net. The researches have provided methods for clearly and concretely describing the process of credit evaluation and cost optimization of network supplier, and have guidance significance for similar other researches

    The safety case and the lessons learned for the reliability and maintainability case

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    This paper examine the safety case and the lessons learned for the reliability and maintainability case

    Reliability Evaluation for Mechanical Systems by Petri Nets

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    The current trend in mechanical engineering is to design mechanical systems with higher stability, reliability, availability and operability. In order to meet the requirement of high reliability for a machine, it is of great importance for designers to seek the weak links in the system and learn the state of the key subsystems, carrying out the remedial measures when necessary. Hence, behavior modeling and failure analysis are the two aspects seriously concerned in the reliability evaluation in mechanical systems. This chapter will introduce new methodologies that use the fuzzy reasoning Petri net (FRPN) models to evaluate the reliability of mechanical systems in reliability prediction, reliability apportionment and reliability analysis. Cases are proposed by analyzing a spacecraft solar array system using the proposed method. Results indicate that the Petri nets models can contribute to a higher accuracy in reliability evaluation for mechanical systems
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