• Journal of information and communication convergence engineering
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• 제22권3호
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• pp.215-220
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• 2024

This paper presents an efficient method for expanding interconnections in scenarios involving the reconstruction of interconnections across arbitrarily divided planes. Conventionally, such situations necessitate rebuilding interconnections based on all targets, ensuring minimal cost but incurring substantial time expenditure. In this paper, we present a tinkered tree algorithm designed to efficiently expand interconnections within a Euclidean plane divided into m randomly generated regions. The primary objective of this algorithm is to construct an optimal tree by utilizing the minimum spanning tree (MST) of each region, resulting in swift interconnection expansion. Interconnection construction is applied in various design fields. Notably, in the context of ad hoc networks, which lack a fixed-wired infrastructure and communicate solely with mobile hosts, the heuristic proposed in this paper is anticipated to significantly reduce costs while establishing rapid interconnections in scenarios involving expanded connection targets.

• 대한기계학회논문집
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• 제11권6호
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• pp.971-974
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• 1987

본 연구에서는 최적설계를 위한 기초로서, 고정된 두 열원사이에서 작동하는 열기관을 예로 들어 운전조건에 따른 출력과 효율의 변화를 정성적으로 설명하여 출력 과 효율의 최대값이 극대값으로 나타남을 보이고, 경제적 측면에서 이들의 의의 및 경 제적 최적운전조건과의 관계 등을 고찰하려 한다.

• 한국경영과학회지
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• 제25권4호
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• pp.15-25
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• 2000

In this paper, we introduce a point-to-multipoint minimum cost flow problem with convex and demand splitting. A source node transmits the traffic along the tree that includes members of the point-to-multipoint connection. The traffic is replicated by the nodes only at branch points of the tree. In order to minimize the sum of arc costs, we assume that the traffic demand can be splitted and transmitted to destination nodes along different trees. If arc cost is linear, the problem would be a Steiner tree problem in networks eve though demand splitting is permitted. The problem would be applied in transmitting large volume of traffic from a serve to clients in Internet environments. Optimality conditions of the problem are presented in terms of fair tree routing. The proposed algorithm is a finite terminating algorithm for $\varepsilon$-optimal solution. convergence of the algorithm is obtained under monotonic condition and strict convexity of the cost function. Computational experiences are included.

• 한국경영과학회지
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• 제14권2호
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• pp.53-66
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• 1989

The Public Vehicle Routing Problem (PVRP) is to find the minimum total cost routes of M or less Public-Vehicles to traverse the required arcs(streets) at least once, and return to their starting depot on a directed network. In this paper, first, a mathematical model is formulated as minimal cost flow model with illegal subtour elimination constraints, and with the fixed cost and routing cost as an objective function. Second, an efficient branch and bound algorithm is developed to obtain an exact solution. A subproblem in this method is a minimal cost flow problem relaxing illegal subtour elimination constraints. The branching strategy is a variable dichotomy method according to the entering nonrequired arcs which are candidates to eneter into an illegal subtour. To accelerate the fathoming process, a tighter lower bound of a candidate subproblem is calculated by using a minimum reduced coast of the entering nonrequired arcs. Computational results based on randomly generated networks report that the developed algorithm is efficient.

• 에너지공학
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• 제1권1호
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• pp.87-96
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• 1992

열교환기의 설치비 및 연간 비용에 주된 영향을 미치는 유틸리티의 소비와 열 교환 장치 수의 최소화를 목적으로 하여 경험법칙을 기초로 한 열교환망 합성 방법을 제안하였다. 본 연구에서 제안하는 열교환망 합성 알고리즘의 특징은 축소된 부문제 생성 기법과 부문제의 해를 구하는 방법에 있으며, 제안한 방법을 문헌에 실린 열교환망 합성 문제에 적용한 결과 이전의 결과보다 열교환장치 및 흐름의 분기등이 감소한 결과를 얻음으로써 본 방법의 우수성을 확인할 수 있었다.

• 한국통신학회논문지
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• 제32권12B호
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• pp.728-734
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• 2007

본 논문에서는 최소 구축비용의 물리적 다중 보안 등급 네트워크 설계를 위한 GOSST 휴리스틱 메커니즘을 제안한다. 다중 보안 등급 네트워크상에서 각 노드는 원하는 보안 등급으로 다른 노드와 통신할 수 있다. 이를 위해서는 불법적인 물리적 접근을 통제할 수 있는 방법이 필요하다. 이러한 네트워크를 최소비용으로 구축하기 위해 GOSST 문제를 적용한다. 이 문제는 NP-Hard 영역이므로 현실적인 해를 얻기 위해서는 적절한 복잡도의 휴리스틱이 필요하다. 본 연구에서는 최소 구축비용의 물리적 다중 보안 등급 네트워크의 설계를 위해, 우리의 이전 거리 직접 GOSST 휴리스틱을 변형한 GOSST 휴리스틱 메커니즘을 제안한다. 이것은 실험 비교 대상인 G-MST에 대하여 평균 29.5%의 구축비용 절감을 보였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.370-372
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• 1986

In this paper we propose a Generalized Minimum Variance Self-tuning Control of the system with an autoregressive noise model. To establish a Generalized Minimum Variance Control, the control input is also included in a cost function and a novel identity is introduced. The effectiveness of this algorithm is demonstrated by the computer simulation.

• The Korean Journal of Ecology
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• 제21권5_1호
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• pp.409-418
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• 1998

A molel study was conducted to determine the optimal sample size for the analysis of the aquatic insect community in a stream reach of the Pangtae Creek, Kangwon-do in October 1995 and may 1996. The results showed that the required minimum sample size varied and depended on the purposes of the community analysis. Acoording to the Species: Area Curve method, at least 16 Surber samplings ($30{\times}30cm$) were required in a stream reach in each spring and fall survey. The species diversity index did not vary significantly as the sample size increased. Based on the coefficient of variation analysis, the minimum sample sizes of 10 were required in order to compare seasonal differences of the community in the study area. Considering the static community structure of aquatic insects, including both species numbers and individual numbers of aquatic insects, 11 and 7 samplings were optimal sizes for the fall and spring survey, respectively. We concluded that 12 Surber samplings from 3 riffle-pool sequences (4 samplings at each riffle-pool sequence) would be required in a stream reach (length 1 km) to obtain reliable as well as cost efficient data. Our model showed that the optimal sample size should be determined by interactions between minimum sample size, the degree of data reliability, and cost efficiency.

• 한국안전학회지
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• 제23권5호
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• pp.125-130
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• 2008

PSC보의 보강 시에 안전도분석을 위한 신뢰성해석과 생애주기비용을 최소화하기 위만 최적설계를 실시하였다. 신뢰성해석은 현재 공용중인 표준단면을 변형시키면서 실시하며 자연적 불확실성과 인위적 불확실성을 고려하였다. 자연적(내재적) 불확실성을 고려하여 최소생애주기비용을 구한 후에, 인위적 불확실성을 최대 90%의 분산까지 고려하여 재해석을 실시하였다. 보강방법에 대한 신뢰성해석과 최소생애주기비용해석은 보강방법을 결정하는데 매우 합리적인 기준을 제시하였다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.195-204
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• 2003

Network optimization is being increasingly important and fundamental issue in the fields such as engineering, computer science, operations research, transportation, telecommunication, decision support systems, manufacturing, and airline scheduling. Networks provide a useful way to modeling real world problems and are extensively used in practice. Many real world applications impose on more complex issues, such as, complex structure, complex constraints, and multiple objects to be handled simultaneously and make the problem intractable to the traditional approaches. Recent advances in evolutionary computation have made it possible to solve such practical network optimization problems. The invited talk introduces a thorough treatment of evolutionary approaches, i.e., hybrid genetic algorithms approach to network optimization problems, such as, fixed charge transportation problem, minimum cost and maximum flow problem, minimum spanning tree problem, multiple project scheduling problems, scheduling problem in FMS.