• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권4호
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• pp.843-859
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• 2024

The university course scheduling problem (UCSP) aims at optimally arranging courses to corresponding rooms, faculties, students, and timeslots with constraints. Previously, the university staff solved this thorny problem by hand, which is very time-consuming and makes it easy to fall into chaos. Even some meta-heuristic algorithms are proposed to solve UCSP automatically, while most only utilize one single algorithm, so the scheduling results still need improvement. Besides, they lack an in-depth analysis of the inner algorithms. Therefore, this paper presents a novel and practical approach based on Tabu search and simulated annealing algorithms for solving USCP. Firstly, the initial solution of the UCSP instance is generated by one construction heuristic algorithm, the first fit algorithm. Secondly, we defined one union move selector to control the moves and provide diverse solutions from initial solutions, consisting of two changing move selectors. Thirdly, Tabu search and simulated annealing (SA) are combined to filter out unacceptable moves in a parallel mode. Then, the acceptable moves are selected by one adaptive decision algorithm, which is used as the next step to construct the final solving path. Benefits from the excellent design of the union move selector, parallel tabu search and SA, and adaptive decision algorithm, the proposed method could effectively solve UCSP since it fully uses Tabu and SA. We designed and tested the proposed algorithm in one real-world (PKNU-UCSP) and ten random UCSP instances. The experimental results confirmed its effectiveness. Besides, the in-depth analysis confirmed each component's effectiveness for solving UCSP.

• 한국시뮬레이션학회논문지
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• 제5권1호
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• pp.91-106
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• 1996

Control Variate (CV) is very useful technique for variance reduction in a wide class of queueing network simulations. However, the loss in variance reduction caused by the estimation of the optimum control coefficients is an increasing function of the number of control variables. Therefore, in some situations, it is required to select an optimal set of control variables to maximize the variance reduction . In this paper, we develop the Adaptive Control Variates (ACV) method which selects an optimal set of control variates during the simulation adatively. ACV is useful to maximize the simulation efficiency when we need iterated simulations to find an optimal solution. One such an example is the Simulated Annealing (SA) because, in SA algorithm, we have to repeat in calculating the objective function values at each temperature, The ACV can also be applied to the queueing network optimization problems to find an optimal input parameters (such as service rates) to maximize the throughput rate with a certain cost constraint.

• 디지털산업정보학회논문지
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• 제17권2호
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• pp.13-20
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• 2021

Placement is a very important step in the VLSI physical design process. It is the problem of placing circuit modules to optimize the circuit performance and reliability of the circuit. It is used at the layout level to find strongly connected components that can be placed together in order to minimize the layout area and propagation delay. The most popular algorithms for circuit placement include the cluster growth, simulated annealing, integer linear programming and genetic algorithm. In this paper we propose a adapted genetic algorithm searching solution space for the placement problem, and then compare it with simulated annealing and genetic algorithm by analyzing the results of each implementation. As a result, it was found that the adaptive genetic algorithm approaches the optimal solution more effectively than the simulated annealing and genetic algorithm.

• 한국콘텐츠학회논문지
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• 제21권7호
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• pp.164-170
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• 2021

VLSI 설계에서의 분할(partitioning)은 기능의 최적화를 위하여 설계하고자 하는 회로의 그룹화(grouping)하는 단계로서 레이아웃(layout)에서 면적과 전파지연의 최소화를 위해 함께 배치할 소자를 결정하는 문제이다. 이러한 분할 문제에서 해를 얻기 위해 사용되는 알고리즘은 Kernighan-Lin 알고리즘, Fiduccia Mattheyses heuristic, 시뮬레이티드 어닐링, 유전자 알고리즘 등의 방식이 이용된다. 본 논문에서는 회로 분할 문제에 대하여 유전자 알고리즘과 확률 진화 알고리즘을 결합한 어댑티드 유전자 알고리즘을 이용한 해 공간 탐색(solution space search) 방식을 제안하였으며, 제안한 방식을 유전자 알고리즘 및 시뮬레이티드 어닐링 방식과 비교, 분석하였고, 어댑티드 유전자 알고리즘이 시뮬레이티드 어닐링 및 유전자 알고리즘보다 더 효과적으로 최적해에 근접하는 것을 알 수 있었다.

• 한국전자파학회논문지
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• 제23권2호
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• pp.196-206
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• 2012

능동 위상 배열 레이더(AESA Radar: Active Electronically Scanned Array radar)는 전자적으로 빔을 조향함으로써 빔 조향 시간이 비약적으로 빨라져 기존의 기계식 빔 조향 레이더에 비해 레이더에서 수행할 수 있는 다중 임무 처리 능력이 크게 향상되었다. 이러한 이유로 레이더에 주어진 시간, 에너지, 처리 능력 등의 한정된 자원을 실시간으로 효율적으로 관리, 운용할 수 있는 레이더 자원 관리 기술의 중요성이 크게 대두되었다. 그 중 레이더 빔 스케줄링 기술은 레이더 자원 관리의 핵심적인 요소라 할 수 있다. 본 논문에서는 simulated annealing을 이용한 추계적 레이더 빔 스케줄링 알고리즘을 제안하고, 이를 기존의 dispatching rule에 기반한 빔 스케줄링 기법과 비교하였다. 빔 처리 지연도(latency)와 주어진 시간 내에서 처리할 수 있는 빔의 개수 측면에서 스케줄링 결과를 비교하여 성능의 우월성을 입증하였으며, 또한 실시간성을 보장하면서도 기존의 규칙 기반 알고리즘보다 성능이 우수함을 보였다.

• Structural Engineering and Mechanics
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• 제35권1호
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• pp.19-35
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• 2010

This paper proposes a hybrid heuristic and criteria-based method of optimum design which combines the advantages of both the iterated simulated annealing (SA) algorithm and the rigorously derived optimality criteria (OC) for structural optimum design of reinforced concrete (RC) buildings under multi-load cases based on the current Chinese design codes. The entire optimum design procedure is divided into two parts: strength optimum design and stiffness optimum design. A modified SA with the strategy of adaptive feasible region is proposed to perform the discrete optimization of RC frame structures under the strength constraints. The optimum stiffness design is conducted using OC method with the optimum results of strength optimum design as the lower bounds of member size. The proposed method is integrated into the commercial software packages for building structural design, SATWE, and for finite element analysis, ANSYS, for practical applications. Finally, two practical frame-shear-wall structures (15-story and 30-story) are optimized to illustrate the effectiveness and practicality of the proposed optimum design method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.107-110
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• 2003

In this paper, the optimal position selection of error sensors and transducers to attenuate interior noise from outside noise sources using active control techniques is presented. To get an optimal control characteristics in adaptive noise control systems, it is necessary to optimize the positions of sensors and transducers. A new type of simulated annealing method has been proposed as searching technique to find optimal transducers and sensors positions in which the sum of the squared pressures at sensor position in an enclosure can be best minimized. Computer simulations and experiments have been performed to show the effectiveness of the proposed method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2766-2768
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• 2003

In this paper, positions of microphones and speakers in adaptive noise control systems are selected using optimization techniques. To get the optimal control characteristics of adaptive noise control system, It is necessary to optimize positions of microphones and speakers. Assume that control speakers are placed in a experimental enclosure several place indoors. Acoustic transfer functions from control speaker positions to microphone positions are measured for simulation program by experiments, and simulated annealing methods are used to select optimal positions of speakers and microphones.

• Industrial Engineering and Management Systems
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• 제11권4호
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• pp.339-345
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• 2012

This research aims to formulate a mathematical model and develop an algorithm for solving a location problem in emergency medical service vehicle parking. To find an optimal parking location which has the least risk score or risk priority number calculated from severity, occurrence, detection, and distance from parking location for emergency patients, data were collected from Pratoom sub-district Disaster Prevention and Mitigation Center from October 2010 to April 2011. The criteria of risk evaluation were modified from Automotive Industry Action Group's criteria. An adaptive simulated annealing algorithm with multiple cooling schedules called multi-agent simulated quenching (MASQ) is proposed for solving the problem in two schemes of algorithms including dual agent and triple agent quenching. The result showed that the solution obtained from both scheme of MASQ was better than the traditional solution. The best locations obtained from MASQ-dual agent quenching scheme was nodes #5 and #133. The risk score was reduced 61% from 6,022 to 2,371 points.

• 조명전기설비학회논문지
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• 제18권1호
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• pp.90-97
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• 2004

본 논문에서는 자동차 소음 등과 같은 외부 소음이 창문 등을 통해 실내로 전파될 때, 이를 제거하기 위한 능동 소음제어 시스템의 제어 스피커 및 마이크로폰의 최적 위치를 결정하는 기법을 제안하였다. 능동 소음제어 시스템의 특성을 최적화하기 위해서는 제어 스피커 및 마이크로폰의 위치를 최적화할 필요가 있는데, 오차 마이크로폰들에서 측정되는 소음의 제곱합을 최소화하는 새로운 형태의 시뮬레이티드 어닐링 기법을 제안하였다. 컴퓨터 시뮬레이션 및 실험을 통하여 제안된 기법의 효용성을 입증하였다.