• 한국컴퓨터정보학회논문지
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• 제21권5호
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• pp.73-77
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• 2016

This paper deals with the network reliability problem that decides the communication line between main two districts while the k districts were destroyed in military communication network that the n communication lines are connected in m districts. For this problem, there is only in used the mathematical approach as linear programming (LP) software package and has been unknown the polynomial time algorithm. In this paper we suggest the heuristic algorithm with O(n) linear time complexity to solve the optimal solution for this problem. This paper suggests the flow path algorithm (FPA) and level path algorithm (LPA). The FPA is to search the maximum number of distinct paths between two districts. The LPA is to construct the levels and delete the unnecessary nodes and edges. The proposed algorithm can be get the same optimal solution as LP for experimental data.

• Journal of applied mathematics & informatics
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• 제41권1호
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• pp.215-228
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• 2023

The ready-made garments (RMG) have been making a crucial contribution about of 81% of total export and 12.36 % of total GDP of the country which is now the single biggest export earner for Bangladesh. The cheap production cost is the key important factor to explore this RMG sector. But these RMG sector is running on the basis of intuition based decisions. Though they are making profit it is not optimal. In this study, a deterministic model is developed to help the RMG to minimize the production cost and to maximize their profit along with optimal utilization of available resources. 10 different types of products are taken from one of the garments factories of Gazipur, Dhaka to prepare this research work. This model suggests the manufacturer on which products along with how much should be produced to meet the future demand by maintaining the lowest production cost that ultimately maximize the profit of the organization, and also helps Bangladesh to compete in the international market with 'Made in Bangladesh'. LINDO programming is used here to solve this LP model.

• 기술혁신연구
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• 제4권1호
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• pp.27-47
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• 1996

The information technology, such as computer, telecommunication, semi- conductor and software technology, is very crucial to enhance the overall level of industrial technology. The workability of linear programming to decide the R&D investment of information technology has been tested in this paper. The case study of Korea during the year 1995 - 2004 suggests that we should enlarge the total investment volume especially on the software technology.

• 대한전자공학회논문지TC
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• 제49권5호
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• pp.21-26
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• 2012

인트라세션 네트워크 코딩은 멀티 홉 무선 네트워크의 스케줄링을 간소화하고 패킷 전송의 효율성을 통하여 처리율을 향상시킬 수 있는 방법으로 제시되었다. 다중 레이트는 대부분의 무선 네트워크에서 사용되고 있으며 기존 연구에서 기회주의적 라우팅 방식과 결합하여 처리율의 증가를 보였다. 본 논문에서는 다중 레이트와 인트라세션 네트워크 코딩 방식을 사용하여 멀티 홉 네트워크 환경에서 처리율을 향상하기 위한 방법을 제안한다. 네트워크 모델을 인트라세션 네트워크 환경으로 모델링하고 제안한 레이트 선택 방법을 통하여 각 노드에서 최적인 전송 속도를 결정한다. 선형계획법을 사용하여 최대 처리율을 도출하고 MATLAB과 lp_solve IDE 프로그램을 이용하여 성능을 평가한다. 성능평가 결과를 통해 다중 레이트를 사용할 경우 단일 레이트 환경에 비하여 처리율이 향상되며 인트라세션 네트워크 코딩 방식은 기회주의적 라우팅 방식에 비하여 처리율이 향상됨을 보였다.

• 산업경영시스템학회지
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• 제38권4호
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• pp.64-71
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• 2015

In this paper, we present a multi-period 0-1 knapsack problem which has the cardinality constraints. Theoretically, the presented problem can be regarded as an extension of the multi-period 0-1 knapsack problem. In the multi-period 0-1 knapsack problem, there are n jobs to be performed during m periods. Each job has the execution time and its completion gives profit. All the n jobs are partitioned into m periods, and the jobs belong to i-th period may be performed not later than in the i-th period, i = 1, ${\cdots}$, m. The total production time for periods from 1 to i is given by $b_i$ for each i = 1, ${\cdots}$, m, and the objective is to maximize the total profit. In the extended problem, we can select a specified number of jobs from each of periods associated with the corresponding cardinality constraints. As the extended problem is NP-hard, the branch and bound method is preferable to solve it, and therefore it is important to have efficient procedures for solving its linear programming relaxed problem. So we intensively explore the LP relaxed problem and suggest a polynomial time algorithm. We first decompose the LP relaxed problem into m subproblems associated with each cardinality constraints. Then we identify some new properties based on the parametric analysis. Finally by exploiting the special structure of the LP relaxed problem, we develop an efficient algorithm for the LP relaxed problem. The developed algorithm has a worst case computational complexity of order max[$O(n^2logn)$, $O(mn^2)$] where m is the number of periods and n is the total number of jobs. We illustrate a numerical example.

• 한국경영과학회지
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• 제26권2호
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• pp.13-46
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• 2001

SDP (Semidefinite Programming), as a sort of “cone-LP”, optimizes a linear function over the intersection of an affine space and a cone that has the origin as its apex. SDP, however, has been developed in the process of searching for better solution methods for NP-hard combinatorial optimization problems. We surveyed the basic theories necessary to understand SDP researches. First, We examined SDP duality, comparing it to LP duality, which is essential for the interior point method, Second, we showed that SDP can be optimized from an interior solution in polynomial time with a desired error limit. finally, we summarized several research papers that showed SDP can improve solution methods for some combinatorial optimization problems, and explained why SDP has become one of the most important research topics in optimization. We tried to integrate SDP theories. relatively diverse and complicated. to survey research papers with our own perspective, and thus to help researcher to pursue their SDP researches in depth.

• 전기학회논문지
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• 제60권4호
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• pp.717-725
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• 2011

In the power system with an electric storage system that can increase utilization rate of the source of such new renewable energy, this paper introduces the approach on the daily unit commitment scheduling that determines simultaneously optimum operational condition and output of thermal generators and electric storage device. The unit commitment is one of the most important issues in economic operation and security of short-term operational plan of the power system. It is to determine on/off status of generator to minimize operational cost during the given period. The committed generator should satisfy various operational limitation such as estimated demand by system, spinning reserve condition within minimum operational cost. In order to determine on/off or charge/discharge/idle condition and output level of units and electric storage system, the MILP(Mixed Integer Linear Programming) is suggested. The proposed approach is the mixed method between LP(Linear Programming) and IP(integer programming) which seeks the value of real number and integer that maximize or minimize function objective within given condition. The daily unit commitment problem with the electric storage system is applied to MILP algorithm through linearization and formulation process. The proposed approach is applied to the test system.

• 한국인터넷방송통신학회논문지
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• 제21권5호
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• pp.189-195
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• 2021

본 논문은 금리가 다른 다중 은행의 다중 국가에서 어느 은행에서 얼마의 대출을 받아야 년 상환액을 최소로 할 수 있는지를 결정하는 대출선택 문제(CLP)를 다룬다. 이 문제에 대해 지금까지는 선형계획법과 같은 수학적 소프트웨어 패키지의 도움 없이는 해를 얻기가 사실상 불가능하였다. 본 논문에서는 수송문제에서 적용하고 있는 최소 금리부터 대출금을 결정하는 최소비용선택법(LCM)으로 초기 실현가능 해를 구하고, 교환 최적화 기법을 적용하여 초기 해를 개선하여 최적 해를 구하는 규칙을 가진 알고리즘을 CLP에 적용하였다. 제안된 알고리즘을 실험한 결과, LCM으로 얻은 초기 해에 대해 단지 최대 2회의 교환 최적화만으로도 최적 해를 얻을 수 있음을 보였다.

• 전기의세계
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• 제32권11호
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• pp.664-669
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• 1983

대규모 system을 취급하는 공학분야에 있어서 Matrix의 demension이 커짐에 따라 전산부담을 줄이기 위한 소요기억용량 절감 및 계산시간의 단축이 주된 관심사 중의 하나가 되어 왔다. LP(Linear Programming)기법 역시 대규모 선형 system에 적용될 경우 Basic Matrix 에 대한 dimensionality 문제를 포함하고 있으며 이에 대한 효과적인 해결방법으로 Bartels-Golub Decomposition 방법이 연구되어 있다. 이 방법은 Chan과 Yip등이 LSGA(Load Shedding and Generator Rescheduling) 문제에의 적용을 시도한 바 있으며, 일반적인 선형최적화 문제뿐만 아니라, dimensionality가 큰 Matrix의 Inverse 계산을 요하는 문제에 널리 적용될 수 있으므로 그 개요를 소개하고자 한다.

• 한국인터넷방송통신학회논문지
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• 제22권5호
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• pp.159-164
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• 2022

선형배정문제 (LAP)와 선형병목배정문제 (LBAP)는 다항시간으로 최적 해를 구하는 알고리즘이 알려져 있지 않은 NP-난제로 분류되어 메타휴리스틱 방법이나 O(m⁴) 계산 복잡도의 선형계획법 (LP) 소프트웨어 패키지나 헝가리안 알고리즘 (HA)을 적용하고 있다. 본 논문은 LAP와 LBAP에 대해 O(mn)=O(m²),m=n 복잡도의 다항시간 알고리즘을 제안하였다. LAP에 대해서는 선택-삭제 방법을, LBAP에 대해서는 삭제-선택 방법을 단순히 적용하였다. 모든 데이터에 적합한 유일한 알고리즘이 존재하지 않는 실험 데이터에 제안된 알고리즘을 적용한 결과, 제안된 알고리즘은 모든 데이터에 대해 최적 해를 구할 수 있었다.