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61.
The structure of sintered nickel composite plaque is characterized by an irregular pore structure with a wide distribution of pore sizes as well as a l  相似文献   
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In this paper, a feasibility study of a randomized space vector switching scheme for three-level inverters is reported. Based on the traditional space vector concept for pulse width modulation (PWM) inverters, the sequence of the space vector is randomized in this scheme. The overall vector, resulting from the randomization, is mathematically identical to that of the traditional space vector. It has been found that the randomized scheme can effectively spread the switching noise over a wide frequency range and at the same time keep the steady-state link capacitor voltage balanced. The proposed scheme has been implemented in real time in a digital controller and its features have been experimentally confirmed  相似文献   
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This study examined the predictive efficacy of 10 rationally derived, archivally coded variables for assessing reoffense risk among extrafamilial child molesters. Follow-up data on 111 child molesters who were discharged from the Massachusetts Treatment Center between 1960 and 1984 were used. Degree of sexual preoccupation with children, paraphilias, and number of prior sexual offenses predicted sexual recidivism. Juvenile and adult antisocial behavior, paraphilias, and low amount of contact with children predicted nonsexual victim-involved and violent recidivism. Area under the receiver-operating characteristic curves in all three analyses indicated discrimination that was substantially better than chance, ranging from .73 to .79. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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The widening of interest and scope of property management and maintenance has attracted a greater diversity of professional disciplines into facilities management. Dr Quah, coordinator of CIB W70 on Management, Maintenance and Modernization of Building facilities, expresses her personal views on the current fascination with the subject.  相似文献   
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Centralized and distributed automated guided vehicle system (AGVS) models for materials handling, and the model for part processing are integrated into a single coherent model. This formulation can be used to collectively schedule and control the entire flexible manufacturing system (FMS) as opposed to the traditional separate scheduling of part processing and material handling. The two AGVS models are based on Petri nets and can be directly used in the scheduling method that uses Petri nets for formulation and heuristic search for solution. This method employs a global search to seek the optimal operation of an entire FMS. Scheduling examples are presented and the method compares favorably with the results simulated using heuristic dispatch rules  相似文献   
69.
In this paper, we present a technique for using an additional parallel neural network to provide adaptive enhancements to a basic fixed neural network-based nonlinear control system. This proposed parallel adaptive neural network control system is applicable to nonlinear dynamical systems of the type commonly encountered in many practical position control servomechanisms. Properties of the controller are discussed, and it is shown that if Gaussian radial basis function networks are used for the additional parallel neural network, uniformly stable adaptation is assured and the approximation error converges to zero asymptotically. In the paper, the effectiveness of the proposed parallel adaptive neural network control system is demonstrated in real-time implementation experiments for position control in a servomechanism with asymmetrical loading and changes in the load  相似文献   
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In this study, it is demonstrated that the incorporation of fluorine can enhance poly-Si/Si interfacial oxide break-up in the poly-Si emitter contacted p+-n shallow junction formation. The annealing temperature for breaking up the poly-Si/Si interfacial oxide has been found to be as low as 900°C. As a result, the junction depth of the BF2-implanted device is much larger than that of the boron-implanted device  相似文献   
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