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An efficient solution procedure for crushing failure in 3D limit analysis of masonry block structures with non-associative frictional joints

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INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES 2015年 69-70卷 252-266页

作者： Portioli, F. Casapulla, C. Cascini, L. Univ Naples Federico II Dept Struct Engn & Architecture I-80134 Naples Italy

A formulation for limit analysis of three-dimensional masonry structures modelled as rigid block assemblages is presented. A concave contact model is adopted for interfaces, using contact points located at the corners of the interface to represent interactions. A no-tension and non-associative frictional behaviour with limited compressive strength is considered for joints. The limit analysis problem is formulated as a second order cone programming problem (SOCP) and an iterative procedure is proposed to model crushing failure and to take into account non-associative frictional behaviour. Applications to numerical case studies are presented for validation. Finally, the accuracy and the computational efficiency of the proposed formulation are evaluated by a comparison with the results of. a full scale experimental sub-assemblage of a masonry pier-spandrel system. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Masonry structures Rigid blocks Limit analysis Crushing failure Non-associative friction second order cone programming Three-dimensional modelling

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Stochastic lot sizing problem with controllable processing times

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OMEGA-INTERNATIONAL JOURNAL OF MANAGEMENT SCIENCE 2015年 53卷 1-10页

作者： Koca, Esra Yaman, Hande Akturk, M. Selim Bilkent Univ Dept Ind Engn TR-06800 Ankara Turkey

In this study, we consider the stochastic capacitated lot sizing problem with controllable processing times where processing times can be reduced in return for extra compression cost. We assume that the compression cost function is a convex function as it may reflect increasing marginal costs of larger reductions and may be more appropriate when the resource life, energy consumption or carbon emission are taken into consideration. We consider this problem under static uncertainty strategy and a service level constraints. We first introduce a nonlinear mixed integer programming formulation of the problem, and use the recent advances in second order cone programming to strengthen it and then solve by a commercial solver. Our computational experiments show that taking the processing times as constant may lead to more costly production plans, and the value of controllable processing times becomes more evident for a stochastic environment with a limited capacity. Moreover, we observe that controllable processing times increase the solution flexibility and provide a better solution in most of the problem instances, although the largest improvements are obtained when setup costs are high and the system has medium sized capacities. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Stochastic lot sizing Controllable processing times second order cone programming

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Heuristics for a continuous multi-facility location problem with demand regions

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COMPUTERS & OPERATIONS RESEARCH 2015年 62卷 237-256页

作者： Dinler, Derya Tural, Mustafa Kemal Iyigun, Cem Middle E Tech Univ Dept Ind Engn TR-06531 Ankara Turkey

We consider a continuous multi-facility location allocation problem where the demanding entities are regions in the plane instead of points. The problem can be stated as follows: given m (closed, convex) polygonal demand regions in the plane, find the locations of q facilities and allocate each region to exactly one facility so as to minimize a weighted sum of squares of the maximum Euclidean distances between the demand regions and the facilities they are assigned to. We propose mathematical programming formulations of the single and multiple facility versions of the problem considered. The single facility location problem is formulated as a second order cone programming (SOCP) problem, and hence is solvable in polynomial time. The multiple facility location problem is NP-hard in general and can be formulated as a mixed integer SOCP problem. This formulation is weak and does not even solve medium-size instances. To solve larger instances of the problem we propose three heuristics. When all the demand regions are rectangular regions with their sides parallel to the standard coordinate axes, a faster special heuristic is developed. We compare our heuristics in terms of both solution quality and computational time. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Facility location problems second order cone programming Minimum sum of squares clustering Hyperbolic smoothing

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Jamming Attacks Reliable Prevention in a Clustered Wireless Sensor Network

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WIRELESS PERSONAL COMMUNICATIONS 2015年第3期85卷 925-936页

作者： Valencia Cordero, Claudio Lisser, Abdel Univ Santiago Chile Dept Ingn Elect Santiago Chile Univ Paris 11 Rech Informat Lab F-91405 Orsay France

A heterogeneous wireless sensor network attacked by jamming is analyzed as a two-player non-cooperative game chance constrained problem, the utility function is based on the signal interference plus noise ratio at the receiver. In view of the problem's stochasticity, second order cone programming is used to solve the game problem. Our preliminary numerical results show that the communication distance between network elements must be taken into account at the time of establishing the design requirements of any reliable application against jamming attacks. Furthermore, it is established that the receiver's sensitivity level is a central parameter for changing the frequency used for the power transmission initially selected by the nodes.

关键词： Wireless sensor network Jamming attack Chance constraints second order cone programming Game theory

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DESIGN OF ROBUST BROADBAND BEAMFORMERS WITH MINIMAX CRITERION

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INTERNATIONAL JOURNAL OF INNOVATIVE COMPUTING INFORMATION AND CONTROL 2015年第1期11卷 19-29页

作者： Hai Huyen Dam Nordholm, Sven Curtin Univ Technol Dept Math & Stat Kent St Perth WA Australia Curtin Univ Technol Dept Elect & Comp Engn Perth WA Australia

Broadband beamformers are known to be sensitive to errors and mismatches in their array elements. This paper proposes a robust minimax beamformer design which takes into account sensor element characteristics. The design formulation minimizes robust integral squared error subject to relaxation constraints on the peak deviation error for the beamformer. The advantage of the proposed formulation is that the design allows a trade-off between the peak deviation error and the sensitivity of the minimax error with respect to variations in sensor element characteristics. This improvement has been achieved with almost no increase in complexity compared with the original minimax problem. Design examples demonstrate that the proposed beamformer is less sensitive with respect to variations in sensor element characteristics when compared to the traditional minimax beamformer with a minor degradation in beamformer performance.

关键词： Robust beamformer design Minimax second order cone programming

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Peak-to-average power ratio reduction using second order cone programming based tone reservation for terrestrial digital video broadcasting systems

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IET COMMUNICATIONS 2009年第7期3卷 1250-1261页

作者： Mahafeno, I. M. Louet, Y. Helard, J. -F. INSA Rennes CNRS UMR 6164 Inst Elect & Telecommun Rennes F-35043 Rennes France SUPELEC F-35576 Cesson Sevigne France

High peak-to-average power ratio (PAPR) is a critical issue in any multicarrier systems using orthogonal frequency division multiplexing, as terrestrial digital video broadcasting (DVB). It can result in low power efficiency and large performance degradation of systems, due to the nonlinearity of high-power amplifier (HPA). A PAPR reduction method based on tone reservation technique with second-order cone programming (SOCP) approach in terrestrial DVB systems is proposed. The authors first demonstrate the superiority of the SOCP optimisation algorithm compared with an iterative gradient-based algorithm, using the current DVB-T parameters: significant PAPR reduction gains can be achieved with only a very small set of subcarriers in the useful bandwidth, making the proposed method more promising in terms of spectral efficiency. Moreover, the proposed solution presents a very good trade-off between PAPR reduction gain and mean transmitted power increase. An overall study, taking into account the limitation of the power level of the dedicated subcarriers and the evaluation of the performances in presence of a nonlinear HPA, is presented. These performances are given in terms of adjacent channel power ratio and bit error rate. The resulting PAPR reduction gain demonstrates that the relevance of the proposed method for the future DVB-T standard is straightforward.

关键词： digital video broadcasting second order cone programming Modulation and coding methods high-power amplifier terrestrial digital video broadcasting systems power amplifiers orthogonal frequency division multiplexing OFDM modulation tone reservation Radio and television broadcasting Optimisation techniques peak-to-average power power ratio reduction quadratic programming

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Adaptive broadband beamformer for nonuniform linear array based on second order cone programming

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Journal of Systems Engineering and Electronics 2009年第2期20卷 278-282页

作者： Chen Peng Hou Chaohuan Ma Xiaochuan Cao Zhiqian Liang Yicong Yan Sheng Inst.of Acoustics Chinese Academy of Sciences Beijing 100080 P. R. China Xi'an Inst.of Electromechanical Information Technology Xi'an 710065 P. R. China

Adaptive broadband beamforraing is a key issue in array applications. The adaptive broadband beamformer with tapped delay line （TDL） structure for nonuniform linear array （NLA） is designed according to the rule of minimizing the beamformer＇s output power while keeping the distortionless response （DR） in the direction of desired signal and keeping the constant beamwidth （CB） with the prescribed sidelobe level over the whole operating band. This kind of beamforming problem can be solved with the interior-point method after being converted to the form of standard second order cone programming （SOCP）. The computer simulations are presented which illustrate the effectiveness of our beamformer.

关键词： information processing technique adaptive broadband beamformer tapped delay line nonuniformlinear array constant beamwidth second order cone programming

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Locally centralized SOCP-based localization technique for wireless sensor network

Locally centralized SOCP-based localization technique for wi...

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International Conference on Advanced Wireless Information and Communication Technologies (AWICT)

作者： Abdelmoneem, Randa M. Shaaban, Eman Ain Shams Univ Fac Comp & Informat Sci Dept Comp Syst Cairo 11566 Egypt

Node localization is one of the essential requirements to most applications of wireless sensor networks. This paper proposes a clustered localization approach for WSNs based on second order cone programming (SOCP). The cluster solves the SOCP problem as a global minimization to get positions of the cluster sensor nodes. To enhance localization accuracy, a cluster level refinement step is implemented using Gauss-Newton optimization. The initial position for the Gauss-Newton optimization is the position drawn from the preprocessor SOCP. The proposed approach scales well for large networks and provides a considerable reduction in computation time while yielding good localization accuracy. (C) 2015 Published by Elsevier B.V.

关键词： Wireless sensor network Localization second order cone programming

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Optimization of Lens Adjustment in Semiconductor Lithography Equipment Using Quadratically Constrained and second-order cone programming

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JOURNAL OF ADVANCED MECHANICAL DESIGN SYSTEMS AND MANUFACTURING 2010年第4期4卷 785-793页

作者： Shinano, Yuji Yoshihara, Toshiyuki Miyashiro, Ryuhei Fukagawa, Youzou Konrad Zuse Zentrum Informat Tech Berlin D-14195 Berlin Germany CANON INC Semicond Prod Equipment PLM Ctr 2 Utsunomiya Tochigi 3213292 Japan Tokyo Univ Agr & Technol Inst Engn Tokyo 1848588 Japan

The present paper considers optimization of lens adjustment in semiconductor lithography equipment. For improving productivity, the laser irradiation power of recent semiconductor lithography equipment has been boosted, which causes significant aberration due to heating during exposure. The aberration of the equipment must be measured or estimated in order to adjust the positions and orientations of the lenses. Since this adjustment is performed sequentially during exposure, the optimization problem to obtain optimal lens adjustment should be solved within a time as short as 100 ms. Although the problem of calculating the optimal lens adjustment can be naturally formulated as a convex minimization problem, in such a formulation the objective function is convex but includes several nondifferentiable points. Hence, optimization methods based on derivatives cannot be applied. Other approaches using derivative-free optimization or meta-heuristic methods cannot guarantee that the obtained solutions are truly optimal. Therefore, we formulate the optimization problem as quadratically constrained and second-order cone programming problems, which can be handled by solvers using an interior point method. Using the proposed formulations, computational experiments demonstrate that the optimal lens adjustment is obtained in a practical computational time, which is much less than 100 ms.

关键词： Semiconductor Lithography Aberration Optimum Design System Engineering Optical Instrument Precision Instrument second order cone programming Quadratically Constrained programming Engineering Optimization

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NONLINEAR MIXED INTEGER programming MODELS AND ALGORITHMS FOR FAIR AND EFFICIENT LARGE SCALE EVACUATION PLANNING

NONLINEAR MIXED INTEGER PROGRAMMING MODELS AND ALGORITHMS FO...

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作者： Vedat Bayram Bilkent University

学位级别：博士

Shelters are safe facilities that protect a population from possible damaging effects of a disaster. Traffic management during an evacuation and the decision of where to locate the shelters are of critical importance to the performance of an evacuation plan. From the evacuation management authority's point of view, the desirable goal is to minimize the total evacuation time by computing a system optimum (SO). However, evacuees may not be willing to take long routes enforced on them by a SO solution; but they may consent to taking routes with lengths not longer than the shortest path to the nearest shelter site by more than a tolerable factor. We develop a model that optimally locates shelters and assigns evacuees to the nearest shelter sites by assigning them to shortest paths, shortest and nearest with a given degree of tolerance, so that the total evacuation time is minimized. As the travel time on a road segment is often modeled as a nonlinear function of the flow on the segment, the resulting model is a nonlinear mixed integer programming model. We develop a solution method that can handle practical size problems using second order cone programming techniques. Using our model, we investigate the trade-off between efficiency and fairness. Disasters are uncertain events. Related studies and real-life practices show that a significant uncertainty regarding the evacuation demand and the impact of the disaster on the infrastructure exists. The second model we propose is a scenario-based two-stage stochastic evacuation planning model that optimally locates shelter sites and that assigns evacuees to shelters and paths to minimize the expected total evacuation time, under uncertainty. The model considers the uncertainty in the evacuation demand and the disruption in the road network and shelter sites. We present a case study for an impending earthquake in Istanbul, Turkey. We compare the performance of the stochastic programming solutions to solutions based on single sc

关键词： Disaster Management Evacuation Traffic Management Shelter Location System Optimal Constrained System Optimal User Equilibrium Nearest Allocation Two-Stage Stochastic programming second order cone programming Benders Decomposition Pareto-optimal Cuts

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