• 융합신호처리학회논문지
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• 제4권3호
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• pp.61-67
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• 2003

We propose a systolic array for dynamic programming which is a technique for solving combinatorial optimization problems. We derive a systolic array for single source shortest path Problem, SA SSSP, and then show that the systolic array serves as dynamic Programming systolic array which is applicable to any dynamic programming problem by developing a systolic array for 0 1 knapsack problem, SA 01KS, with SA SSSP for a basis. In this paper, each of SA SSSP and SA 01KS is modeled and simulated in RT level using VHDL, then synthesized to a schematic and finally implemented to a layout using the cell library based on 0.35${\mu}{\textrm}{m}$ 1 poly 4 metal CMOS technology.

• 대한전자공학회논문지SD
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• 제49권8호
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• pp.1-9
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• 2012

Quantum-Inspired Evolutionary Algorithm(QEA)은 알고리즘 자체에 충분한 data-level parallelism이 내재되어 있어 GPU를 이용한 가속에 용이하다. 그러나 효과적인 실행시간의 단축을 위해서는 CPU와 GPU에의 적절한 task-mapping이 필요하다. 이때 단순히 함수 자체의 병렬성만을 고려하는 것이 아니라 CPU와 GPU간의 데이터 전송도 고려하여 task-mapping을 할 필요가 있다. 또한 추가적인 성능향상을 위하여 zero-copy host memory와 적절한 execution configuration의 사용, 그리고 memory coalescing 등을 이용할 수 있다. 그 결과 30,000개의 item수를 가진 0-1 knapsack problem에 대한 QEA의 수행을 multi-threading CPU에 비해 평균 3.69배 빠르게 할 수 있었다.

• Industrial Engineering and Management Systems
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• 제3권2호
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• pp.92-99
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• 2004

We consider the ATM switching node location problem (ANLP). In this problem, there are two kinds of facilities, hub facilities and remote facilities, with different capacities and installation costs. We are given a set of customers with each demand requirements, a set of candidate installation sites of facilities, and connection costs between facilities. We need to determine the locations to place facilities, the number of facilities for each selected location, the set of customers who are connected to each installed hub via installed remote facilities with minimum cost, while satisfying demand requirements of each customer. We formulate this problem as a general integer programming problem and solve it to optimality. In this paper, we present a preprocessing procedure to tighten the formulation and develop a branch-and-price algorithm. In the algorithm, we consider the integer knapsack problem as the column generation problem. Computational experiments show that the algorithm gives optimal solutions in a reasonable time.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.63-64
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• 2007

The Underwater Wireless Sensor Networks (UWSN) consists of sensor nodes equipped with limited sensing coverages, energy resources and communication capacity. Hence, the deployment and movement algorithm is a key issue that needs to be organized in order to improve the sensing efficiency of the networks. In this paper, we use a Queen problem and Knapsack problem to prevent the reiteration phenomenon of sensors, to guarantee improvement sensing coverage and efficiency in the 3D UWSN.

• 산업경영시스템학회지
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• 제35권2호
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• pp.57-63
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• 2012

소프트웨어 개발에 있어서 소프트웨어를 시장에 출시하는 계획을 수립하는 것은 소프트웨어를 이루고 있는 기능들을 구현하는 데 제약이 되는 조건들(기술, 자원, 위험, 예산 등)을 만족하면서 계획된 출시기간에 이들 기능들을 할당하는 일이다. 이와 같이 소프트웨어 출시를 계획하는 것은 소프트웨어 제품라인에 대해서 고려할 때 더욱 복잡해진다. 본 연구에서는 소프트웨어 제품라인에 있어서 소프트웨어 출시 계획을 수립하기 위한 문제를 우선순위 제약하의 다수 0-1 배낭문제로 수리 모형화하고, 이를 풀기 위한 최적해법이 개발된다. 최적해법은 동적 계획법이 주가 되고, 문제의 크기를 줄이기 위하여 휴리스틱과 축소방법이 이용된다.

• 한국경영과학회지
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• 제24권3호
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• pp.93-107
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• 1999

We consider the development of an integer programming model and algorithm for the ATM switching node location problem. There are two kinds of facilities, hub facilities and remote facilities, with different capacities and installation costs. Each customer needs to be connected to one or more hub facilities via remote facilities, where the hub(remote) facilities need to be installed at the same candidate installation site of hub(remote) facility. We are given a set of customers with each demand requirements, a set of candidate installation sites of facilities, and connection costs between facilities, We need to determine the locations to place facilities, the number of facilities for each selected location, the set of customers who are connected to each installed hub facilities via installed remote facilities with minimum costs, while satisfying demand requirements of each customer. We formulate this problem as a general integer programming problem and solve it to optimality. In this paper, we develop a branch-and-cut algorithm with path variables. In the algorithm, we consider the integer knapsack polytope and derive valid inequalities. Computational experiments show that the algorithm works well in the real world situation. The results of this research can be used to develop optimization algorithms to solve capacitated facility location problems.

• 한국지능시스템학회논문지
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• 제22권4호
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• pp.414-424
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• 2012

문제 인스턴스 탐색 혹은 자동 생성은 알고리즘 분석 및 테스트에 적용될 수 있으며, 하드웨어, 소프트웨어 프로그램, 계산 이론 등 다양한 수준에서 연구되어온 주제이다. 본 연구에서는 해(解) 공간에 사용된 목적값-거리 상관관계 분석을 문제 인스턴스 공간에 적용하였다. 문제 인스턴스의 목적값은 문제에 따라 알고리즘의 수행 시간과 최적해를 잘 구하는 정도로 정의하였다. 이러한 정의는 문제 인스턴스의 난이도로 해석할 수 있다. 상관관계는 3가지 측면에서 분석하였다: 첫째, 알고리즘과 거리 함수에 따른 상관관계 차이, 둘째, 알고리즘의 개선 전/후의 상관관계 변화, 셋째, 문제 인스턴스 공간과 해당 문제의 해 공간 사이의 연관성. 본 논문은 문제 인스턴스 공간에 상관계수 분석이 어떻게 적용될 수 있는지 보여주며, 문제 인스턴스 공간 분석을 본격적으로 다루는 첫번째 시도이다.

• ETRI Journal
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• 제45권5호
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• pp.874-886
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• 2023

A joint resource-optimization scheme is investigated for nonorthogonal multiple access (NOMA)-enhanced scalable video coding (SVC) multicast in unmanned aerial vehicle (UAV)-assisted radio-access networks (RANs). This scheme allows a ground base station and UAVs to simultaneously multicast successive video layers in SVC with successive interference cancellation in NOMA. A video quality-maximization problem is formulated as a mixed-integer nonlinear programming problem to determine the UAV deployment and association, RAN spectrum allocation for multicast groups, and UAV transmit power. The optimization problem is decoupled into the UAV deployment-association, spectrum-partition, and UAV transmit-power-control subproblems. A heuristic strategy is designed to determine the UAV deployment and association patterns. An upgraded knapsack algorithm is developed to solve spectrum partition, followed by fast UAV power fine-tuning to further boost the performance. The simulation results confirm that the proposed scheme improves the average peak signal-to-noise ratio, aggregate videoreception rate, and spectrum utilization over various baselines.

• 한국멀티미디어학회논문지
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• 제9권12호
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• pp.1560-1571
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• 2006

In order to transmit multimedia streams over the network with a timely changing channel bandwidth such as Internet, scalable video coding schemes have been studied to represent video in flexible bitstream. Much research has been made on how to represent encoded media(such as video) bitstream in scalable ways. In this paper, rte propose an optimal selection of the objects for MPEG-4 bitstream adaptation to meet a given constraint. We adopt a multiple choice knapsack problem with multi-step selection for the MPEG-4 objects with different bit-rate scaling levels in the MPEG-4 bitstream. The bitstream adaptation based on the optimal selection result is then to fetch the necessary parts of the MPEG-4 bitstream to constitute an adapted version of the original MPEG-4 binary resource. The experiment results show that the optimal selection of MPEG-4 objects for a given constraint can promisingly be made which meets the given constraint.

• Journal of Communications and Networks
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• 제16권5호
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• pp.559-567
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• 2014

In this paper, a framework for power allocation of downlink transmissions in orthogonal frequency division multiple access-based decode-and-forward cellular relay networks is investigated. We consider a system with a single base station communicating with multiple users assisted by multiple relays. The relays have limited power which must be divided among the users they support in order to maximize the data rate of the whole network. Advanced power allocation schemes are crucial for such networks. The optimal relay power allocation which maximizes the data rate is proposed as an upper bound, by finding the optimal power requirement for each user based on knapsack problem formulation. Then by considering the fairness, a new relay power allocation scheme, called weighted-based scheme, is proposed. Finally, an efficient power reallocation scheme is proposed to efficiently utilize the power and improve the data rate of the network. Simulation results demonstrate that the proposed power allocation schemes can significantly improve the data rate of the network compared to the traditional scheme.