• Title, Summary, Keyword: Linear programming (LP)

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Optimal Base Station Clustering for a Mobile Communication Network Design

  • Hong, Jung-Man;Lee, Jong-Hyup;Lee, Soong-Hee
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.5
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    • pp.1069-1084
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    • 2011
  • This paper considers an optimal base station clustering problem for designing a mobile (wireless) communication network. For a given network with a set of nodes (base stations), the problem is to optimally partition the set of nodes into subsets (each called a cluster) such that the associated inter-cluster traffic is minimized under certain topological constraints and cluster capacity constraints. In the problem analysis, the problem is formulated as an integer programming problem. The integer programming problem is then transformed into a binary integer programming problem, for which the associated linear programming relaxation is solved in a column generation approach assisted by a branch-and-bound procedure. For the column generation, both a heuristic algorithm and a valid inequality approach are exploited. Various numerical examples are solved to evaluate the effectiveness of the LP (Linear Programming) based branch-and-bound algorithm.

Design of FIR Filters with Finite Precision Coefficients Using LP(Linear Programming) (선형계획을 이용한 유도 정밀도 계수 FIR 필터의 설계)

  • 조남익;이상욱
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.12
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    • pp.2386-2396
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    • 1994
  • In this paper, an optimal algorithm for the design of 1-D FIR filters with finite precision coefficients is proposed. The algorithm is based on the observation that the frequency constraints of a sub-problems(SP) in the branch and bound algorithm, which repeatedly use LP(linear programming), are closely related with those of neighboring SPs. By using the relationship between the SPs, the proposed algorithm reduces the number of constraints required for solving each SP with Lp, whereas the conventional algorithm employs all the constraints, which are required for solving the initial problem. Thus, the overall computational load for the design of FIR filters with finite precision coefficients is significantly alleviated, compared to the conventional branch and bound algorithm. Also, a new branching scheme for the design of FIR filters with sum-of-power-of-two(SOPOT) coefficients is proposed. It is shown that the computational load for the design fo SOPT coefficient filters can be further reduced with the new branching scheme.

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Development of The Robust State Estimator using Linear Programming (선형계획법을 이용한 견실한 상태추정기의 개발에 관한 연구)

  • Lim, Jae-Sup;Kwon, Hyung-Seok;Kim, Hong-Rae
    • Proceedings of the KIEE Conference
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    • pp.181-183
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    • 2001
  • This paper presents a robust power system state estimator using linear programming(LP). LP state estimators minimize the weighted sum of the absolute values of the measurement residuals. In this paper, WLS(weighted least square) and WLAV(weighted least absolute value) state estimators are run with same measurement sets including bad data in order to compare the robustness to bad data and convergence characteristics of the two methods. Simulations with three test cases are performed and the results are presented, using IEEE 14 bus system.

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A Study on Determination of Optimal Incentives of DSM Programs by Linear Programming (선형계획법에 의한 수요관리 프로그램의 최적 지원금 결정에 관한 연구)

  • Lee, Byung-Ha;Kim, Jung-Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.3
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    • pp.517-523
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    • 2011
  • A lot of DSM (Demand Side Management) programs have been implemented to promote the effective utilization of resources and the rational development of power industry, and various economic analyses and policy-based studies on DSM have been executed to determine effective subsidy budget. In this paper, a new objective function for deciding an optimal incentive allocation among various programs is presented by introducing the maximization of the total saving power of the programs. For simplicity, the objective function and the constraints is linearized to apply LP(Linear Programming) method. LP program based on Simplex Method was developed by MATLAB. An optimal incentive allocation of 4 DSM programs is presented by the use of the developed MATLAB program.

Comparison of Optimization Algorithms for Available Transfer Capability Assessment in Interconnected Systems (연계계통에서 가용송전용량 평가를 위한 최적화 알고리즘의 비교)

  • Kim, Kyu-Ho;Song, Kyung-Bin
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.55 no.12
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    • pp.549-554
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    • 2006
  • Available transfer capability(ATC) is an important indicator of the usable amount of transmission capacity accessible by several parties for commercial trading in power transaction activities. This paper deals with an application of optimization technique for available transfer capability(ATC) calculation and analyzes the results of ATC by considering several constraints. Especially several optimization techniques are used to solve the ATC problem with state-steady security constraints. The results are compared with that of repeat power flow(RPF), sequential quadratic programming(SQP) and linear programming(LP). The proposed method is applied to 10 machines 39 buses model systems to show its effectiveness.

The Maximin Linear Programming Knapsack Problem With Extended GUB Constraints (확장된 일반상한제약을 갖는 최대최소 선형계획 배낭문제)

  • 원중연
    • Journal of the Korean Operations Research and Management Science Society
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    • v.26 no.3
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    • pp.95-104
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    • 2001
  • In this paper, we consider a maximin version of the linear programming knapsack problem with extended generalized upper bound (GUB) constraints. We solve the problem efficiently by exploiting its special structure without transforming it into a standard linear programming problem. We present an O(n$^3$) algorithm for deriving the optimal solution where n is the total number of problem variables. We illustrate a numerical example.

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On a Two Dimensional Linear Programming Knapsack Problem with the Extended GUB Constrain (확장된 일반상한제약을 갖는 이차원 선형계획 배낭문제 연구)

  • Won, Joong-Yeon
    • Journal of Korean Institute of Industrial Engineers
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    • v.27 no.1
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    • pp.25-29
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    • 2001
  • We present a two dimensional linear programming knapsack problem with the extended GUB constraint. The presented problem is an extension of the cardinality constrained linear programming knapsack problem. We identify some new properties of the problem and derive a solution algorithm based on the parametric analysis for the knapsack right-hand-side. The solution algorithm has a worst case time complexity of order O($n^2logn$). A numerical example is given.

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An Analysis of Optimal Operation Strategy of ESS to Minimize Electricity Charge Using Octave (Octave를 이용한 전기 요금 최소화를 위한 ESS 운전 전략 최적화 방법에 대한 분석)

  • Gong, Eun Kyoung;Sohn, Jin-Man
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.4
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    • pp.85-92
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    • 2018
  • Reductions of the electricity charge are achieved by demand management of the load. The demand management method of the load using ESS involves peak shifting, which shifts from a high demand time to low demand time. By shifting the load, the peak load can be lowered and the energy charge can be saved. Electricity charges consist of the energy charge and the basic charge per contracted capacity. The energy charge and peak load are minimized by Linear Programming (LP) and Quadratic Programming (QP), respectively. On the other hand, each optimization method has its advantages and disadvantages. First, the LP cannot separate the efficiency of the ESS. To solve these problems, the charge and discharge efficiency of the ESS was separated by Mixed Integer Linear Programming (MILP). Nevertheless, both methods have the disadvantages that they must assume the reduction ratio of peak load. Therefore, QP was used to solve this problem. The next step was to optimize the formula combination of QP and LP to minimize the electricity charge. On the other hand, these two methods have disadvantages in that the charge and discharge efficiency of the ESS cannot be separated. This paper proposes an optimization method according to the situation by analyzing quantitatively the advantages and disadvantages of each optimization method.

A Study on the Constrained Dispatch Scheduling Using Linear Programming for TWBP (선형계획법을 이용한 양방향입찰시장에서의 제약급전계획 연구)

  • Kim Gwang Won;Lee Jong-Bae;Jung Jung-Won
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.53 no.10
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    • pp.573-580
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    • 2004
  • A new real-time constrained dispatch scheduling (CDS) is needed for TWBP. The CDS needs to be performed at every dispatch period to decide generation power of scheduling generators and amounts of scheduling load. Therefore, the CDS is not based on real generation costs but on bidding data of market participants with some constraints such as power balance, generation limits, ancillary service, and transmission line limits. This paper selects linear programming(LP) as an optimization tool for the CDS and presents effective formulae for the LP application. This paper also presents the way of minimizing the number of variables and constraints of the LP to improve real-time applicability.

Optimized Land Use by Integrated Use of Fuzzy-LP and GIS (Fuzzy-LP와 GIS의 결합을 통한 토지의 최적 이용문제)

  • 전철민
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.20 no.3
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    • pp.273-282
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    • 2002
  • Although the influence of GIS has been proved in a variety of applications, there also have been some research issues about that the coupling of GIS with other mathematical or engineering tools is necessary to meet various needs of specialized problem domains. Linear Programming, a mathematical technique used in optimal distribution of given quantity, can enhance its usability by integrating with GIS since LP basically does not include means to deal with spatial data. The limitation of the traditional LP technique is that it requires explicitly defined conditions, which is impractical or impossible in such decision making processes as in land use problems that use less crisp decision factors. This study develops a method to incorporate such fuzzy situations by integrating Fuzzy-LP that employs fuzzy logic and GIS. The GIS provides data to or displays data from the Fuzzy-LP processes in the integrated system. This methodology is illustrated to solve a land use distribution problem.