This paper presents comparative performance analysis of Automatic generation control with two recently developed meta-heuristic nature inspired algorithms called backtracking search algorithm/Wind driven optimization ...
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ISBN:
(纸本)9781509043071
This paper presents comparative performance analysis of Automatic generation control with two recently developed meta-heuristic nature inspired algorithms called backtracking search algorithm/Wind driven optimization algorithm. An attempt has been made to show the superiority of Wind driven optimization algorithm over backtracking search algorithm to improve the transient performance of automatic generation control of an interconnected two-area multi-source power system with physical constraints governor dead band, generation rate constraints, reheat system. Comparative studies of BSA and WDO with PI/PID controller reveals that WDO based PID controller in both the areas improve the transient performance to a greater extent following small load perturbation(s).
This paper presents a methodology for topology optimization of transmission line towers. In this approach, the structure is divided in main modules, which can assume different pre-established topologies (templates). A...
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This paper presents a methodology for topology optimization of transmission line towers. In this approach, the structure is divided in main modules, which can assume different pre-established topologies (templates). A general rule for the templates creation is also presented, which is based in terms of the design practice and feasibility of prototype testing. Thus, these allow that the optimal solution has an important characteristic of direct industrial application. Furthermore, during the optimization process the size and shape of the structure are optimized simultaneously to the topology choice. For numerical examples, two structures were assessed. The first one is a transmission line tower studied in CIGRE (2009). Eight different load cases were considered. The second one is a single circuit, self-supported 115 kV transmission line tower. The structure was subjected to a cable conductor rupture scenario and a wind load hypothesis. In both examples the constraints from the ASCE 10-97 (2000) were applied. Due to the non-convex nature of the problem and to the presence of discrete variables in the procedure, the optimization was conducted through the Firefly algorithm (FA) and the backtracking search algorithm (BSA), which are two modem heuristic algorithms. The results for the size, size and shape, and size, shape and topology optimization are presented and discussed, as well as an analysis of the performance of the algorithms. It is shown that the proposed scheme is able to reduce up to 6.4% of the structural weight, when compared to a classical size optimization procedure on original structures. (C) 2015 Elsevier Ltd. All rights reserved.
Multimodal biometric systems aim to improve the recognition accuracy by minimizing the limitations of unimodal systems. In this paper, different fusion schemes based on feature-level and match score-level fusion are e...
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Multimodal biometric systems aim to improve the recognition accuracy by minimizing the limitations of unimodal systems. In this paper, different fusion schemes based on feature-level and match score-level fusion are employed to provide a robust recognition system. The proposed method presents a multimodal approach based on face-palmprint biometric systems by match score-level fusion technique. Local binary patterns are performed as local feature extractor to obtain efficient texture descriptor. Feature selection is performed using backtracking search algorithm to select an optimal subset of face and palmprint extracted features. Hence, computation time and feature dimension are considerably reduced while obtaining the higher level of performance. Then, match score-level fusion is performed to show the effectiveness and accuracy of the proposed method. In score-level fusion, face and palmprint scores are normalized using tanh normalization and matching scores of individual classifiers are fused using sum rule method. The experimental results are tested on a developed virtual multimodal database combining FERET face and PolyU palmprint databases. The results demonstrate a significant improvement compared with unimodal identifiers, and the proposed approach significantly outperforms other face-palmprint multimodal systems with a recognition accuracy of 99.17 %. Additionally, the proposed approach is compared with the state-of-the-art methods.
The focus of this paper is on proposing new schemes based on score level and feature level fusion to fuse face and iris modalities by employing several global and local feature extraction methods in order to effective...
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The focus of this paper is on proposing new schemes based on score level and feature level fusion to fuse face and iris modalities by employing several global and local feature extraction methods in order to effectively code face and iris modalities. The proposed schemes are examined using different techniques at matching score level and feature level fusion on CASIA Iris Distance database, Print Attack face database, Replay Attack face database and IIIT-Delhi Contact Lens iris database. The proposed schemes involve the consideration of Particle Swarm Optimization (PSO) and backtracking search algorithm (BSA) in order to select optimized features and weights to achieve robust recognition system by reducing the number of features in feature level fusion of the multimodal biometric system and optimizing the weights assigned to the face-iris multimodal biometric system scores in score level fusion step. Additionally, in order to improve face and iris recognition systems and subsequently the recognition of multimodal face-iris biometric system, the proposed methods attempt to correct and align the location of both eyes by measuring the iris rotation angle. Demonstration of the results based on both identification and verification rates clarifies that the proposed fusion schemes obtain a significant improvement over unimodal and other multimodal methods implemented in this study. Furthermore, the robustness of the proposed multimodal schemes is demonstrated against spoof attacks on several face and iris spoofing datasets. (C) 2015 Elsevier B.V. All rights reserved.
This study presents a novel islanding detection and optimal load shedding scheme for radial distribution systems integrated with dispersed generation (DG). A simple and effective passive islanding detection method is ...
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This study presents a novel islanding detection and optimal load shedding scheme for radial distribution systems integrated with dispersed generation (DG). A simple and effective passive islanding detection method is developed based on the phase-space technique and using a probabilistic neural network-based classifier. After the system detects unintentional islanding state, it utilises an optimal load shedding scheme to prevent system collapse due to load-generation mismatch and voltage instability encountered in the islanded part of the system. The optimal load shedding scheme is developed based on the backtracking search algorithm. Extensive tests conducted with the DigSilent Power Factory((R)) software and MATLAB((R)) software on the IEEE 33-bus system with four DG units considering several scenarios of islanding condition were utilised to evaluate the effectiveness of the proposed islanding detection method and the optimal load shedding scheme. The results showed that the proposed method can effectively detect the islanding events and stabilise the islanded part of the system with minimum load curtailment.
In this paper, the performance of four optimization techniques i.e. Grey Wolf Optimizer (GWO), backtracking search algorithm (BSA), Differential Evolution (DE), and Bat algorithm (BA) have been investigated for optimi...
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ISBN:
(纸本)9781467372312
In this paper, the performance of four optimization techniques i.e. Grey Wolf Optimizer (GWO), backtracking search algorithm (BSA), Differential Evolution (DE), and Bat algorithm (BA) have been investigated for optimizing the scaling factors of fuzzy proportional-integral controller (FPIC). Jacketed continuous stirred tank reactor (CSTR) has been considered for step set-point and trajectory tracking of reactor temperature. The present work has been simulated in LabVIEW (TM). The performance of aforementioned algorithms has been evaluated by comparing the cost function Integral of Absolute Error for step set-point and trajectory tracking. On the basis of simulation results, it can be inferred that, GWO outperformed other optimization algorithms for all considered cases.
In developing countries, the increasing utilization of health services, due to a great life expectancy, is followed by a reduction in incomes from the public health system and from private insurance companies, to the ...
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In developing countries, the increasing utilization of health services, due to a great life expectancy, is followed by a reduction in incomes from the public health system and from private insurance companies, to the payment of medical procedures. Beyond this scenery, it is mandatory an effective hospital cost control though the utilization of planning tools. This work is intended to contribute to the reduction of hospital costs, proposing a new tool for planning human resources utilization in hospital plants. Specifically, it is proposed a new tool for human resources allocation in health units. The solution to the allocation problem uses the CSP technique (Constraint Satisfaction Problem) associated with the backtracking search algorithm. With the objective of enhancing the backtracking search algorithm performance a new heuristics is proposed. Through some simulations the performance of the proposed heuristics is compared to the other heuristics previously published in literature: remaining minimum values, forward checking and grade heuristics. Another important contribution of this work is the mathematical modeling of the constraints, that could be unary, multiple, numeric and implicit constraints. In the results it is presented a case study of a human resource allocation in a cooperative health service. Based on the results, it is proposed that for a real allocation problems solution, the best approach is to combine the remaining minimum values heuristics with the grade heuristics, to select the best unit allocation to be filled, and then use the proposed heuristic to select the best physician to the chosen unit allocation. This association shows a satisfactory result for the human resource allocation problem of the case study, with an algorithm convergence time of 46.7 min with no backtracks. The same problem when manually resolved took about more than 50 h. (C) 2011 Elsevier Ltd. All rights reserved.
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