• 정보처리학회논문지B
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• 제10B권3호
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• pp.249-256
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• 2003

다중 에이전트 시스템에서 가장 중요한 문제는 여러 에이전트가 서로 효율적인 협동(coordination)을 통해서 목표(goal)를 성취하는 것과 다른 에이전트들과의 충돌(collision) 을 방지하는 것이다. 본 논문에서는 먹이 추적 문제의 목표를 효율적으로 성취하기 위해 새로운 전략 방법을 제안한다. 제안된 제어 전략은 다중 에이전트를 제어하기 위해 강화 학습을 이용하였고, 에이전트들간의 거리관계와 공간 관계를 고려하였다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제27권8호
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• pp.834-845
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• 2000

대부분의 에이전트는 그들이 생성될 때 자신이 수행하는 작업에 대한 계획을 갖고 있다. 이러한 에이전트들이 모여 멀티 에이전트 시스템을 이룰 경우 하나의 복잡한 작업을 수행하기 위해 미리 정의된 각 에이전트의 계획을 그대로 사용하게 되면 각 계획 규칙 사이의 연관성 등을 고려하지 못하기 때문에 시스템의 작업 처리 효율성이 떨어진다. 이를 해결하기 위해서는 에이전트가 갖고 있는 독자적인 계획을 통합하는 것이 요구된다. 이러한 계획의 통합은 미리 정의된 각 에이전트의 계획 사이의 관계를 파악하여 병렬적인 작업 수행을 가능하게 한다. 본 논문에서는 멀티 에이전트 시스템을 이루는 에이전트들이 자신의 작업 수행을 위한 계획을 갖고 있다는 가정 하에 하나의 큰 작업을 효율적으로 처리하기 위해 에이전트들의 계획을 네트워크 형태로 표현하고 이를 통합하여 작업을 수행하는 방법을 제시한다. 이 방법은 기존의 연구들이 다루고 있는 계획 순서 등과 관련된 에이전트 조정 문제를 자연스럽게 해결할 뿐만 아니라 다른 계획에 영향을 미치지 않는 각 에이전트의 독자적인 계획을 병렬로 수행시켜 작업 처리 시간을 단축시키는 효과를 낸다.

• Asia pacific journal of information systems
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• 제10권2호
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• pp.23-49
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• 2000

We proposed a conceptual design of the web-based agent model for global supply chain management(GSCM), where agents representing autonomous operational units, such as suppliers, factories, distribution center and customers, cooperate and are coordinated through the information exchange. The agent model assumed the hierarchical federated system. In the federated system, the agents of the same region are grouped and linked to the region-specific facilitator only through which communication between agents is allowed. The facilitator is responsible for monitoring and controlling the conversations consisting of the message flows across the agents. A web-based user presentation was also designed so that human users could involve in collaborative settings into the GSCM multi-agent system. In the conversation protocols which allow for complex coordinated behavior among agents, the KQML was extended to represent the messages. A GSCM scenario where the supply chain is formed upon customer order and supply decision is made was used to demonstrate the dynamics of the conversation protocols.

• 전기학회논문지
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• 제57권4호
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• pp.537-542
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• 2008

The protection against transient instability and consequent out-of-step condition is a major concern for the utility industry. Unstable system may cause serious damage to system elements such as generators and transmission lines. Therefore, out-of-step detection is essential to operate a system safely. Also, a multi-agent system is one that consists of a number of agents, which interact with one another. Multi-agent systems(MAS) can offer the flexibility and the adaptability to the previous algorithm. In this paper, the detection algorithm of out-of-step is designed by multi-agent system and implemented by EMTP-MODELS. To verify performance of the proposed algorithm based on multi-agent system, simulations by EMTP have been carried out.

• 한국멀티미디어학회논문지
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• 제11권3호
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• pp.353-363
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• 2008

단일 에이전트 환경에서는 Q-학습의 학습 시간을 줄이기 위해서 학습결과를 전파시키거나 일렬의 행동을 패턴으로 만들어 학습한다. 다중 에이전트 환경에서는 동적인 환경과 다수의 에이전트 상태를 고려해야하기 때문에 학습에 필요한 시간이 단일 에이전트 환경보다 길어지게 된다. 이 논문에서는 단일 에이전트 환경에서 시간 단축을 위해서 유한개의 행동으로 정책을 만들어 학습하는 매크로 행동을 다중 에이전트 환경에 적합한 내시 Q-학습에 적용함으로써 다중 에이전트 환경에서 Q-학습 시간을 줄이고 성능을 높이는 방법을 제안한다. 실험에서는 다중 에이전트 환경에서 매크로 행동을 이용한 에이전트와 기본 행동만 이용한 에이전트의 내시 Q-학습 성능을 비교했다. 이 실험에서 네 개의 매크로 행동을 이용한 에이전트가 목표를 수행할 성공률이 기본 행동만 이용한 에이전트 보다 9.46% 높은 결과를 얻을 수 있었다. 매크로 행동은 기본 행동만을 이용해서 적합한 이동 행동을 찾아도 매크로 행동을 이용한 더 낳은 방법을 찾기 때문에 더 많은 Q-값의 변화가 발생되었고 전체 Q-값 합이 2.6배 높은 수치를 보였다. 마지막으로 매크로 행동을 이용한 에이전트는 약 절반의 행동 선택으로도 시작위치에서 목표위치까지 이동함을 보였다. 결국 에이전트는 다중 에이전트 환경에서 매크로 행동을 사용함으로써 성능을 향상시키고 목표위치까지 이동하는 거리를 단축해서 학습 속도를 향상시킨다.

• KIEE International Transactions on Power Engineering
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• 제2A권3호
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• pp.89-94
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• 2002

In this paper, a protection system using a Multi-Agent concept for power distribution networks is proposed. Every digital over current relay(OCR) is developed as an agent by adding its own intelligence, self-tuning and communication ability. The main advantage of the Multi-Agent concept is that a group of agents work together to achieve a global goal which is beyond the ability of each individual agent. In order to cope with frequent changes in the network operation condition and faults, an OCR agent, suggested in this paper, is able to detect a fault or a change in the network and find its optimal parameters for protection in an autonomous manner considering information of the whole network obtained by communication between other agents. Through this kind of coordination and information exchanges, not only a local but also a global protective scheme is completed. Simulations in a simple distribution network show the effectiveness of the suggested protection system.

• Journal of information and communication convergence engineering
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• 제17권3호
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• pp.167-173
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• 2019

This study investigates the problem of leader-following consensus for multi-agent systems with output saturations. This study assumes that the agents are described as a neutrally stable system, and the leader agent generates the bounded trajectory within the saturation level. Then, the objective of the leader-following consensus is to track the trajectory of the leader by exchanging information with neighbors. To solve this problem, we propose an observer-based distributed consensus algorithm. Then, we provide a consensus analysis by applying the Lyapunov stability theorem and LaSalle's invariance principle. The result shows that the agents achieve the leader-following consensus in a global sense. Moreover, we can achieve the consensus by choosing any positive control gain. Finally, we perform a numerical simulation to demonstrate the validity of the proposed algorithm.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.268-271
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• 2003

In this paper, we propose a new framework based on negotiatory mobile multi agent system, and implement a mobile multi agent environment based on DECAF(Distributed Environment-Centered Agent Framework) which is one of the distributed agent development toolkit so as to implement a new PDS(Personal Digital Library System). The new framework has some optimality and higher performance in distributed environments.

• 한국자동차공학회논문집
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• 제12권5호
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• pp.125-135
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• 2004

The validity of simulation has been well-established for decades in areas such as computer and communication system. Recently, the technique has become entrenched in specific areas such as transportation and traffic forecasting. Several methods have been proposed for investigating complex traffic flows. However, the dynamics of vehicles and their driver's characteristics, even though it is known that they are important factors for any traffic flow analysis, have never been considered sufficiently. In this paper, the traffic simulation using a multi-agent approach with considering vehicle dynamics is proposed. The multi-agent system is constructed with the traffic environment and the agents of vehicle and driver. The traffic environment consists of multi-lane roads, nodes, virtual lanes, and signals. To ensure the fast calculation, the agents are performed on the based of the rules to regulate their behaviors. The communication frameworks are proposed for the agents to share the information of vehicles' velocity and position. The model of a driver agent which controls a vehicle agent is described in the companion paper. The vehicle model contains the nonlinear subcomponents of engine, torque converter, automatic transmission, and wheels. The simulation has proceeded for an interrupted and uninterrupted flow model. The result has shown that the driver agent performs human-like behavior ranging from slow and careful to fast and aggressive driving behavior, and that the change of the traffic state is closely related with the distance and the signal delay between intersections. The system developed shows the effectiveness and the practical usefulness of the traffic simulation.

• 한국가스학회지
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• 제8권2호
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• pp.28-34
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• 2004

Enhanced methodologies for process diagnosis and abnormal situation management have been developed for the last two decades. However, there is no single method that always shows better performance over all kinds of diagnostic problems. In this paper, a framework of message-passing, cooperative, intelligent diagnostic agents is presented for improved on-line fault diagnosis through cooperative problem solving of different expertise. A group of diagnostic agents in charge of different process functional perform local diagnoses in parallel; exchange related information with other diagnostic agents; and cooperatively solve the global diagnostic problem of the whole process plant or business units just like human experts would do. For their better understanding, sharing and exchanging of process knowledge and information, we also suggest a way of remodeling processes and protocols, taking into account semantic abstracts of process information and data. The benefits of the suggested multi-agents-based approach are demonstrated by the implementations for solving the diagnostic problems of various chemical processes.