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1.
Gonzalo Romero Guillermo Durn Javier Marenco Andrs Weintraub 《International Transactions in Operational Research》2013,20(6):767-794
Ship routing problems are a particular kind of routing problems where the vehicles to be routed are vessels or ships, usually in maritime environments. In contrast to land routing, ship routing has unique features, including overnight trips, disjoint time windows, not necessarily prespecified routes, and a great uncertainty derived from weather conditions. In this work we present a special ship routing problem, which incorporates many features present in general ship routing settings. We discuss aspects related with data gathering and updating, which are particularly difficult in the context of ship routing. Additionally, we present a GRASP algorithm to solve this problem. We apply our solution approach to a salmon feed supplier based in southern Chile, and present computational results on real data. 相似文献
2.
Even though many consensus protocol algorithms have been developed over the last several years in the literature, robustness properties of these algorithms involving nonlinear dynamics have been largely ignored. Robustness here refers to sensitivity of the control algorithm achieving semistability and consensus in the face of model uncertainty. In this paper, we examine the robustness of several control algorithms for network consensus protocols with information model uncertainty of a specified structure. In particular, we develop sufficient conditions for robust stability of control protocol functions involving higher‐order perturbation terms that scale in a consistent fashion with respect to a scaling operation on an underlying space with the additional property that the protocol functions can be written as a sum of functions, each homogeneous with respect to a fixed scaling operation, that retain system semistability and consensus. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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In cluster analysis, a fundamental problem is to determine the best estimate of the number of clusters; this is known as the automatic clustering problem. Because of lack of prior domain knowledge, it is difficult to choose an appropriate number of clusters, especially when the data have many dimensions, when clusters differ widely in shape, size, and density, and when overlapping exists among groups. In the late 1990s, the automatic clustering problem gave rise to a new era in cluster analysis with the application of nature-inspired metaheuristics. Since then, researchers have developed several new algorithms in this field. This paper presents an up-to-date review of all major nature-inspired metaheuristic algorithms used thus far for automatic clustering. Also, the main components involved during the formulation of metaheuristics for automatic clustering are presented, such as encoding schemes, validity indices, and proximity measures. A total of 65 automatic clustering approaches are reviewed, which are based on single-solution, single-objective, and multiobjective metaheuristics, whose usage percentages are 3%, 69%, and 28%, respectively. Single-objective clustering algorithms are adequate to efficiently group linearly separable clusters. However, a strong tendency in using multiobjective algorithms is found nowadays to address non-linearly separable problems. Finally, a discussion and some emerging research directions are presented. 相似文献
5.
周利利 《数字社区&智能家居》2009,5(2):942-943,958
手持导航产品中,电磁干扰对产品性能的影响巨大。该文重点描述PND产品中EMI定位和整改问题的一般分析方法和手段,即通过组合使用通用的电、磁场探头,GPS有源天线,电压探头进行近场扫描,准确定位PND中的干扰源和干扰路径,并举例说明这些方法的应用。 相似文献
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通过分析等效辐射功率、电磁辐射功率密度和电磁辐射防护距离概念及计算模型,探讨绿色无辐射TD-LTE室内覆盖基站建设模式. 相似文献
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时域有限差分(FDTD)法中的时域近远场变换法计算天线远场辐射特性的优点是通过一次计算可以得到全频域的结果,缺点是数据存储量大、计算速度慢。文献R.Pascaud、S.Wang和G.Carat介绍了一种基于二维空间数据压缩的时域近远场变换方法,此方法可以大大减少数据存储量从而减少近远场变换时间。基于减少数据量的考虑,本文提出一种基于时域抽样法的近远场变换算法以提高近远场变换计算效率。为验证新算法的有效性,分别用经典算法和时域抽样法对七单元八木天线远场辐射特进行计算,结果表明本算法可有效减少数据存储量,提高近远场变换效率。 相似文献
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随着全球3G网络的高速发展和智能手机的快速普及,国内外移动支付业务呈现爆发式增长,市场空间巨大.根据用户支付方式的不同,移动支付可分为远程支付和近场支付两大类,应用涵盖公交、购物、电子票券等方面.综合分析SIM Pass、RF-SIM、NFC-SWP、APP四类主流移动支付方案的技术特征与市场现状,并探讨移动互联网时代移动支付的发展趋势. 相似文献
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Shihong Ding 《International journal of control》2016,89(4):815-832
This paper considers the problem of global stabilisation of a class of generalised cascaded systems. By using the extended adding a power integrator technique, a global controller is first constructed for the driving subsystem. Then based on the homogeneous properties and polynomial assumption, it is shown that the stabilisation of the driving subsystem implies the stabilisation of the overall cascaded system. Meanwhile, by properly choosing some control parameters, the global finite-time stability of the closed-loop cascaded system is also established. The proposed control method has several new features. First, the nonlinear cascaded systems considered in the paper are more general than the conventional ones, since the powers in the nominal part of the driving subsystem are not required to be restricted to ratios of positive odd numbers. Second, the proposed method has some flexible parameters which provide the possibility for designing continuously differentiable controllers for cascaded systems, while the existing designed controllers for such kind of cascaded systems are only continuous. Third, the homogenous and polynomial conditions adopted for the driven subsystem are easier to verify when compared with the matching conditions that are widely used previously. Furthermore, the efficiency of the proposed control method is validated by its application to finite-time tracking control of non-holonomic wheeled mobile robot. 相似文献
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M. Anuradha G. Mani T. Shanthi N. R. Nagarajan P. Suresh C. Bharatiraja 《计算机系统科学与工程》2022,43(1):381-396
In the digital area, Internet of Things (IoT) and connected objects generate a huge quantity of data traffic which feeds big data analytic models to discover hidden patterns and detect abnormal traffic. Though IoT networks are popular and widely employed in real world applications, security in IoT networks remains a challenging problem. Conventional intrusion detection systems (IDS) cannot be employed in IoT networks owing to the limitations in resources and complexity. Therefore, this paper concentrates on the design of intelligent metaheuristic optimization based feature selection with deep learning (IMFSDL) based classification model, called IMFSDL-IDS for IoT networks. The proposed IMFSDL-IDS model involves data collection as the primary process utilizing the IoT devices and is preprocessed in two stages: data transformation and data normalization. To manage big data, Hadoop ecosystem is employed. Besides, the IMFSDL-IDS model includes a hill climbing with moth flame optimization (HCMFO) for feature subset selection to reduce the complexity and increase the overall detection efficiency. Moreover, the beetle antenna search (BAS) with variational autoencoder (VAE), called BAS-VAE technique is applied for the detection of intrusions in the feature reduced data. The BAS algorithm is integrated into the VAE to properly tune the parameters involved in it and thereby raises the classification performance. To validate the intrusion detection performance of the IMFSDL-IDS system, a set of experimentations were carried out on the standard IDS dataset and the results are investigated under distinct aspects. The resultant experimental values pointed out the betterment of the IMFSDL-IDS model over the compared models with the maximum accuracy 95.25% and 97.39% on the applied NSL-KDD and UNSW-NB15 dataset correspondingly. 相似文献
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Geometric homogeneity with applications to finite-time stability 总被引：10，自引：0，他引：10
This paper studies properties of homogeneous systems in a geometric, coordinate-free setting. A key contribution of this paper is a result relating regularity properties of a homogeneous function to its degree of homogeneity and the local behavior of the dilation near the origin. This result makes it possible to extend previous results on homogeneous systems to the geometric framework. As an application of our results, we consider finite-time stability of homogeneous systems. The main result that links homogeneity and finite-time stability is that a homogeneous system is finite-time stable if and only if it is asymptotically stable and has a negative degree of homogeneity. We also show that the assumption of homogeneity leads to stronger properties for finite-time stable systems. 相似文献
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A global continuous control scheme for the finite-time or (local) exponential stabilisation of mechanical systems with constrained inputs is proposed. The approach is formally developed within the theoretical framework of local homogeneity. This has permitted to solve the formulated problem not only guaranteeing input saturation avoidance but also giving a wide range of design flexibility. The proposed scheme is characterised by a saturating-proportional-derivative type term with generalised saturating and locally homogeneous structure that permits multiple design choices on both aspects. The work includes a simulation implementation section where the veracity of the so-cited argument claiming that finite-time stabilisers are faster than asymptotical ones is studied. In particular, a way to carry out the design so as to, indeed, guarantee faster stabilisation through finite-time controllers (beyond their finite-time convergence) is shown. 相似文献
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Helen Josephine V L Ramchand Vedaiyan V. M. Arul Xavier Joy Winston J A. Jegatheesan D. Lakshmi Joshua Samuel Raj 《计算机系统科学与工程》2023,45(1):701-717
The Internet of Things (IoT) technologies has gained significant interest in the design of smart grids (SGs). The increasing amount of distributed generations, maturity of existing grid infrastructures, and demand network transformation have received maximum attention. An essential energy storing model mostly the electrical energy stored methods are developing as the diagnoses for its procedure was becoming further compelling. The dynamic electrical energy stored model using Electric Vehicles (EVs) is comparatively standard because of its excellent electrical property and flexibility however the chance of damage to its battery was there in event of overcharging or deep discharging and its mass penetration deeply influences the grids. This paper offers a new Hybridization of Bacterial foraging optimization with Sparse Autoencoder (HBFOA-SAE) model for IoT Enabled energy systems. The proposed HBFOA-SAE model majorly intends to effectually estimate the state of charge (SOC) values in the IoT based energy system. To accomplish this, the SAE technique was executed to proper determination of the SOC values in the energy systems. Next, for improving the performance of the SOC estimation process, the HBFOA is employed. In addition, the HBFOA technique is derived by the integration of the hill climbing (HC) concepts with the BFOA to improve the overall efficiency. For ensuring better outcomes for the HBFOA-SAE model, a comprehensive set of simulations were performed and the outcomes are inspected under several aspects. The experimental results reported the supremacy of the HBFOA-SAE model over the recent state of art approaches. 相似文献
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Paola Festa Mauricio G. C. Resende 《International Transactions in Operational Research》2009,16(1):1-24
A greedy randomized adaptive search procedure (GRASP) is a metaheuristic for combinatorial optimization. It is a multi-start or iterative process, in which each GRASP iteration consists of two phases, a construction phase, in which a feasible solution is produced, and a local search phase, in which a local optimum in the neighborhood of the constructed solution is sought. Since 1989, numerous papers on the basic aspects of GRASP, as well as enhancements to the basic metaheuristic have appeared in the literature. GRASP has been applied to a wide range of combinatorial optimization problems, ranging from scheduling and routing to drawing and turbine balancing. This is the first of two papers with an annotated bibliography of the GRASP literature from 1989 to 2008. This paper covers algorithmic aspects of GRASP. 相似文献
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Luis F. Santos Simone L. Martins Alexandre Plastino 《International Transactions in Operational Research》2008,15(4):387-416
Recent research has shown that the hybridization of metaheuristics is a powerful mechanism to develop more robust and efficient methods to solve hard optimization problems. The combination of different techniques and concepts behind metaheuristics, if well designed, has the potential to exploit their advantages while diminishing their drawbacks, which results in methods suited to a more diverse set of real problems. The DM‐GRASP heuristic is one such hybrid method that has achieved promising results. It is a hybrid version of the GRASP metaheuristic that incorporates a data‐mining process. In this work, we review how this hybridization was designed and survey the results of its practical applications evaluated until now. 相似文献
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Vinícius Leal do Forte Flávio Marcelo Tavares Montenegro José André de Moura Brito Nelson Maculan 《International Transactions in Operational Research》2016,23(6):1185-1199
We propose algorithmic frameworks based on the iterated local search (ILS) metaheuristic to obtain good‐quality solutions for the Euclidean Steiner tree problem (ESTP) in n dimensions. This problem consists in finding a tree with minimal total length that spans p points given in an n‐dimensional Euclidean space and, eventually, also some additional points whose insertion contributes to reduce the total length of the tree. These ILS approaches make use of both the tree enumeration structure, called topology‐describing vector, and the exact minimization step of a well‐known branch‐and‐bound method for the ESTP. Computational results are provided. 相似文献
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介绍了远场光和近场光的物理图景 ,根据它们的不同性质并结合应用 ,指出远场光学探测的空间分辨能力受光学衍射极限的约束 ,近场光学探测可以突破光学衍射极限。应用近场光学设计新的传感器和探测器 ,能够提高灵敏度和分辨力 相似文献
18.
Paola Festa Mauricio G. C. Resende 《International Transactions in Operational Research》2009,16(2):131-172
A greedy randomized adaptive search procedure (GRASP) is a metaheuristic for combinatorial optimization. It is a multi-start or iterative process, in which each GRASP iteration consists of two phases, a construction phase, in which a feasible solution is produced, and a local search phase, in which a local optimum in the neighborhood of the constructed solution is sought. Since 1989, numerous papers on the basic aspects of GRASP, as well as enhancements to the basic metaheuristic, have appeared in the literature. GRASP has been applied to a wide range of combinatorial optimization problems, ranging from scheduling and routing to drawing and turbine balancing. This is the second of two papers with an annotated bibliography of the GRASP literature from 1989 to 2008. In the companion paper, algorithmic aspects of GRASP are surveyed. In this paper, we cover the literature where GRASP is applied to scheduling, routing, logic, partitioning, location, graph theory, assignment, manufacturing, transportation, telecommunications, biology and related fields, automatic drawing, power systems, and VLSI design. 相似文献
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Mario Villalobos-Arias Carlos A. Coello Coello Onésimo Hernández-Lerma 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2006,10(11):1001-1005
This paper analyzes the convergence of metaheuristics used for multiobjective optimization problems in which the transition probabilities use a uniform mutation rule. We prove that these algorithms converge only if elitism is used. 相似文献
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The problem of global asymptotic stabilisation is investigated for a class of upper-triangular systems with uncontrollable linearisation. A notion of generalised homogeneity is introduced in this article, providing a new insight and a deeper perspective on how to categorise nonlinear terms into the higher-order and equal-order terms in a non-traditional way. The delicate analysis and new categorisation of the vector field make it possible to encompass more general nonlinearities. A globally stabilising controller is recursively constructed by a bottom-up, step-by-step procedure, containing the equal-order terms as its indispensable components. It is illustrated that the results obtained in this article incorporate and extend existing results for the global stabilisation of upper-triangular systems. 相似文献