• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2000.04a
• /
• pp.401-404
• /
• 2000

최근 제조환경은 다양한 소비자의 요구, 제품의 짧은 수명 주기, 치열한 국내외 경쟁 등으로 특징 지워진다. 이러한 제조환경에 적응하기 위하여 FMS(flexible manufacturing systems)에서 기계의 종류는 다기능 공작기계(versatile machine)로 구성되고, 공구는 빠른 공구 이동장치(tool delivery system)에 의하여 제어되는 추세에 있다. 공구 이동장치를 이용하여 가공 중에 필요한 공구를 다른 기계 또는 공구 저장장치로부터 공급하는 동적 공구할당 전략하의 FMS 에서는 공구의 가용여부(작업 일정계획)를 고려한 작업순서 결정이 중요한 문제이다. 본 연구에서는 동적 공구할당 전략하의 FMS 에서 한 부품 또는 한 셋업에서 공구대기시간을 줄이는 방향으로 공구할당을 수행하는 작업순서 알고리즘을 제안하고, 시뮬레이션 실험을 통하여 다른방법으로 공구할당을 수행하는 알고리즘과 비교함으로써 본 작업순서 알고리즘의 우수성을 입증한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.29 no.1
• /
• pp.377-382
• /
• 2005

This paper deals with productivity improvement of stevedoring system by pooling opertaions of transport vehicle at automated container terminal. Usually, in traditional container terminals, grouping operations of transport vehicle are applied for container crane because vehicle routing path is simple and vehicle assignment is easy. But this static assignment(SA) operation that arrsign vehicles to container crane ar apron reduces flexibility of vehicles. Therefore, This paper presented 4 dynamic assignment(DA) method to improve efficiency of vehicles. These 4 dynamic assignment method consider present situations of container crane such as sequence(Se), queue time(Qt), productivity(Pr), numeric of vehicle assignment(Nv), numeric of buffer(Nb) at vehicles assignment. At the results, dynamic assignment operation to consider Qt, Nv, Nb is most efficient and by next time, dynamic assignment operation to consider Se is superior more than static assignment operation. but, dynamic assignment operation to consider Pr or Qt of container crane only is inefficient than static assignment operation.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.12
• /
• pp.856-864
• /
• 2019

The weapon-target assignment (WTA) problem is a matter of effectively allocating weapons to a number of threats. The WTA in a rapidly changing dynamic environment of engagement must take into account both of properties of the threat and the weapon and the effect of the previous decision. We propose a method of applying the Greedy Randomized Adaptive Search Procedure (GRASP) algorithm, a kind of meta-heuristic method, to derive optimal solution for a dynamic WTA problem. Firstly, we define a dynamic WTA problem and formulate a mathematical model for applying the algorithm. For the purpose of the assignment strategy, the objective function is defined and time-varying constraints are considered. The dynamic WTA problem is then solved by applying the GRASP algorithm. The optimal solution characteristics of the formalized dynamic WTA problem are analyzed through the simulation, and the algorithm performance is verified via the Monte-Carlo simulation.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.04a
• /
• pp.671-674
• /
• 2002

동적 메모리 할당 방식은 사전에 그 메모리의 크기를 결정할 수 없는 경우에 효과적인 프로그래밍 기술이다. 하지만 메모리 조각화 문제와 최악의 경우 실행 시간을 예측할 수 없는 단점 때문에 실시간 시스템에는 거의 적용되지 않고 있다. 본 연구에서는 리눅스 기반의 실시간 시스템을 위한 동적 메모리 할당 알고리즘인 QB(Ouick-Buddy)를 제안한다 제안된 알고리즘은 작은 크기의 메모리 요구에 대해서 워드 크기별로 프리 리스트를 관리하고, 큰 크기의 메모리 요구에 대해서는 이진 버디 시스템을 이용하여 관리한다. 이 알고리즘에서는 작은 크기의 메모리 요구에 대해 완전-적합(exist-fit) 전략을 사용하여 메모리 이용 효율을 증가시킨다. 또한 큰 크기의 메모리 요구에 대해서 버디 시스템을 적용함으로써 외부 조각화를 제거시키고 처리량(throughput)을 증가시킨다. 제안된 알고리즘의 성능을 확인하기 위해서 제안된 알고리즘과 이진 버디 시스템(binary buddy system), 빠른-적합(quick-fit)의 메모리 이용 효율성 및 메모리 조각화 율을 비교할 것이다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.10a
• /
• pp.92-94
• /
• 2000

비디오 저장 서버를 설계하는데 가장 주안을 두어야 할 점은 서버의 이용률을 증가시키고 그에 따른 비용을 최소화 해야 한다는 점이다. 이를 위한 서버로 분산 비디오 저장 서버가 주로 이용되고 있고, 그 목적으로는 균등한 비디오 할당과 부하조정(load balancing)이 제안되어 왔다. 이에 대한 방안의 하나로 디스크 기반의 비디오 저장 서버 클러스터에서 부하 시프팅(load shifting)이 그 목적을 이루기 위한 한가지 방법으로 연구되었다. 이것은 동일한 용량의 서버로 구성된 비디오 서버 클러스터에서 비디오를 다른 서버에 복사해 놓고 사용되고 있는 비디오 요구시 그 비디오에 대한 요구를 다른 서버의 복사본으로 이동시킴으로써 서버들에 대해 균등한 비디오 할당을 하고 서버나 비디오의 추가와 같은 동적인 변화에 대해 데이터 활당 및 부하 조정을 감안하여 제안된 것이다. 이 논문에서는 기존의 동일한 서버만을 사용한 것과는 달리 용량이 서로 다른 서버나 비디오를 추가할 경우에 요구되는 최적의 비디오 데이터 할당과 부하 조정에 관한 전략에 관하여 설명한다.

• Journal of Navigation and Port Research
• /
• v.30 no.3 s.109
• /
• pp.235-240
• /
• 2006

This study analyzed equipment operation strategy of ATC(Automated Transfer Crane) in order to development efficiency ATC operation logic for apply to domestic ACT(Automated Container Terminal). Improving productivity of ACT developed dynamic operation logic and established dispatching rule. As a result of simulation experiment reduced waiting time and interference time of ATC. Thus, we can improve productivity of ACT using dynamic operation logic and interference avoidance strategy.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.1
• /
• pp.165-171
• /
• 2005

In this paper, the centralized dynamic load-balancing was processed effectively by using the network based parallel genetic algorithm. Unlike the existing method using genetic algorithm, the performance of central scheduler was improved by distributing the process for the searching of the optimal task assignment to clients. A roulette wheel selection and an elite preservation strategy were used as selection operation to improve the convergence speed of optimal solution. A chromosome was encoded by using sliding window method. And a cyclic crossover was used as crossover operation. By the result of simulation for the performance estimation of central scheduler according to the change of flexibility of load-balancing method, it was verified that the performance is improved in the proposed method.

• Journal of Korea Game Society
• /
• v.6 no.3
• /
• pp.13-22
• /
• 2006

Games such as sports, RTS, RPG, which teams of players play, require advanced artificial intelligence technology for team management. The existing artificial intelligence enables an intelligent agent to have the autonomy solving problem by itself, but to lack interaction and cooperation between agents. This paper presents "Level Unified Approach Method" with effective role allocation and autonomy in multiagent system. This method allots sub-goals to agents using role information to accomplish a global goal. Each agent makes a decision and takes actions by itself in dynamic environments. Global goal of Team coordinates to allocated role in tactics approach. Each agent leads interactive cooperation by sharing state information with another using Databoard, As each agent has planning capacity, an agent takes appropriate actions for playing allocated roles in dynamic environments. This cooperation and interactive operation between agents causes a collision problem, so it approaches at tactics side for controlling this problem. Our experimental result shows that "Level Unified Approach Method" has better performance than existing rental approach method or de-centralized approach method.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.11B
• /
• pp.1016-1022
• /
• 2003

The EPON has been actively studied as one of the access networks for the economic configuration of FTTH. The EPON must support the dynamic bandwidth allocation to the subscribers in order to support the QoS due to its base on Ethernet technology EFM SG, which is actively working for the standardization of EPON, also recently decided to select DBA. Therefore in this paper, we designed a ONU buffer scheduling algorithm(AIWFQ) and a scheme of DBA(Class-based FCFS) for the OLT suitable for embodying MPCP of the EPON. In this paper, we proposed methods that the EPON system can make use of by measuring end to end process delay time and the buffer size in order to implement the algorithm by using the OPNET.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.2B
• /
• pp.272-278
• /
• 2004

The EPON has been actively studied as one of the access networks for the economic configuration of FTTH. The EPON must support the dynamic bandwidth allocation to the subscribers in order to support the QoS due to its base on Ethernet technology. EFM SG, which is actively working for the standardization of EPON, also recently decided to select DBA. Therefore in this paper, we designed a ONU buffer scheduling algorithm (AIWFQ) and a scheme of DBA(Class-based FCFS) for the OLT suitable for embodying MPCP of the EPON. In this paper, we proposed methods that the EPON system can make use of by measuring end to end process delay time and the buffer size in order to implement the algorithm by using the OPNET.