• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1628-1635
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• 2008

In this paper, the motion coordination algorithm of mobile agents in active sensor network is proposed to track the dynamic boundary for environmental monitoring. While most of dynamic boundary tracking algorithms in the literature were studied under the assumption that the boundary and/or its evolving rate is known a priori, the proposed algorithm is assumed that the individual active agent can measure the state of environment locally without any information of the boundary. When the boundary is evolving dynamically, the formation of active agents is designed to achieve two objectives. One is to track boundary layer based on the measured information and a small deviation. The other is to maintain a uniform distance between adjacent agents. The algorithm structure based on a state diagram is proposed to achieve these two objectives. Finally, it will be shown in the simulations that all given agents converge to a desired boundary layer and maintain a formation along the boundary. (e.g., a circle, an ellipse, a triangle and a rectangle)

• Proceedings of the Korea Society for Simulation Conference
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• 1997.04a
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• pp.81-85
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• 1997

In a virtual environment, agents must demonstrate some degree of realism and interactivity. This paper discusses the algorithm that enables agents to navigate a virtual road network realistically and interactively. The road description files written in this language provide the information of road environments to the navigating agents and the scene visualizer. We call this navigating agent in the road an ambient car. The ambient cars must follow the traffic rules as human does. To do this, the ambient car should continuously check its circumstances, such as, the traffic lights, lanes, road signs, and other ambient cars. Because of the huge scale of road network and the large number of ambient cars, the algorithm considers only the area where the participant is currently located. By this locality, the performance of the whole system does not fluctuate much in different situations. The behavior of ambient cars according to the predefined rules may appear monotonous. We added probability distribution functions to introduce some randomness. We implemented the above idea on silicon Graphics Indigo 2 workstation. The ambient car exhibited its awareness of lanes, traffic lights, and other cars. The participants could hardly distinguish between a human-controlled car and computer-controlled ambient car generated by the algorithm.

• Journal of KIISE:Software and Applications
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• v.27 no.8
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• pp.834-845
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• 2000

Most agents are associated with plan rules for their tasks when they are created. In a multi-agent system in which many agents are interacting, the direct use of predefined plan rules of each agents may slow down the system due to the lack of recognition of the relationship among plan rules of the agents. In order to overcome this, we need to analyze and integrate the agent's plan rules to facilitate concurrent rule execution. This paper proposes a method that integrates and executes local plan rules of task agents in a multi-agent environment. The results of the integration are represented in a network structure. For domain task execution, a task agent collects other task agents' plan rules and builds an integrated domain network, which is exploited to achieve the goal. The agent problem solving by using the domain network enables not only the concurrent plan execution but the solution of coordination problems.

• Journal of the Korea Computer Graphics Society
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• v.17 no.4
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• pp.23-30
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• 2011

We propose an intelligent ribbon road network for automatic vehicle simulation, and a real-time algorithm for large-scale, realistic traffic simulation based on artificial energy functions. Our method reconstructs a road network automatically from both GIS (Geographic Information System) real-world data and synthetic models. Such automatic road network helps us to easily simulate almost every possible scenario such as intersections, ramps, etc. In order to simulate agents' movement, we design car-environment interaction energy and car-car interaction energy functions. Car agents move along the road network according to the proposed energy functions while avoiding collisions with other car agents.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.2
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• pp.287-312
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• 2011

Internet chat programs and instant messaging services are becoming increasingly popular among Internet users. One of the crucial issues with Internet chat is how to manage the corresponding pairs of questions and answers in a sequence of conversations. Although many novel methodologies have been introduced to cope with this problem, most are poor in managing interruptions, organizing turn-taking, and conveying comprehension. The Internet environment is recently evolving into a 3D environment, but the problems with managing chat dialogues with the standard 2D text-based chat have remained. Therefore, we propose a more realistic communication model for chat agents in 3D virtual space in this paper. First, we propose a new method to measure the capacity of communication between chat agents and a novel visualization method to depict the hierarchical structure of chat dialogues. In addition, we are concerned with communication networks for virtual people (avatars) living in virtual worlds. In this paper we consider a microscopic aspect of a social network in a relatively short period of time. Our experiments show that our model is highly effective in a virtual chat environment, and the communication network based on our model greatly facilitates investigation of a very large and complicated communication network.

• Journal of Internet Computing and Services
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• v.3 no.2
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• pp.87-95
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• 2002

Due to rapid development of high speed wire/wireless internet technologies, at the current age, it cares into being one phenomenon that the internet business is able to work on anyplace and anytime. In this environment, a technology of mobile agent provides very useful mechanism for personal handheld devices because of supporting migration as autonomously executable software object Instead of users. Therefore, this paper focuses on Implementing a mobile agent platform for personal handheld devices, which supports mobile agents in wire/wireless internet environment. To do this, we construct the system with modified JAMAS, based on Java, in our previous research. Based on our proposed system, we implement the browsing application in personal handheld devices to access the MIB(Management Information Base) on SNMP(Simple Network Management Protocol), which supervises network environment on wire/wireless internet. This proposed application system is easily to access the MIB managed by SNMP agent. then provides network map viewer and updates the MIB through the browser to network administrator. As a result, we can support application area of mobile agents such as hare network management. M-Commerce, integration of remote database systems, active message and active network with personal handheld devices.

• The KIPS Transactions:PartC
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• v.14C no.6
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• pp.537-544
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• 2007

A home network is a residential local area network in which digital home appliances are connected with each other. Applying the mobile agent technology to the home network is expected to provide a new computing model. In particular, mobility and asynchronous ability of mobile agent can be used to reduce network traffic generated for managing home appliances. However, in order to apply the mobile agent concept to the home network, access control for mobile agents is necessary. In the existing home network system, there is one special server, sometimes called home server This server generally has mapping tables to be updated periodically, which describes access control lists between users' authorities and corresponding devices. In this paper, we propose a role-based access control framework with mobile agents in home networks. This framework, called Secure KAgent framework, is designed and implemented based on KAgent system. It has two main characteristics: to control access permissions based on Role-Based Access Control(RBAC) scheme and to safety assign roles to mobile agents by role tickets.

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.117-124
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• 2010

Appling centralized network management architecture SNMP(Simple Network Management Protocol) to wireless networks causes the network overhead, NAT(Network Address Translation) problem on AP, and performance degradation of mobile nodes. In this paper, we propose an integrated management scheme for wired and wireless networks using mobile agents in order to solve above problems. In our proposed scheme, SNMP is applied to manage wired networks and MAs of SNMP are implemented in APs or wireless nodes to manage wireless networks. In addition, we propose a method to reduce the redundant OID information within SNMP response messages. Through the analysis, we show that our proposal resolves the given problems and reduces the processing delay of the wireless nodes.

• Journal of Information Technology Applications and Management
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• v.17 no.1
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• pp.141-155
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• 2010

We develop an intelligent information system in a multilayer electronic supply chain network. Using the internet for supply chain management (SCM) is a key interest for contemporary managers and researchers. It has been realized that the internet can facilitate SCM by making real time information available and enabling collaboration between trading partners. Here, we propose a multi-agent system to analyze the performance of the elements of a supply network based on the attributes of the information flow. Each layer consists of elements which are differentiated by their performance throughout the supply network. The proposed agents measure and record the performance flow of elements considering their web interactions for a dynamic route selection. A dynamic programming approach is applied to determine the optimal route for a customer in the end-user layer.

• Journal of the Korea Society for Simulation
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• v.10 no.1
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• pp.83-92
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• 2001

For the prevention of the network intrusion from damaging the system, both IDS (Intrusion Detection System) and Firewall are frequently applied. The collaboration of IDS and Firewall efficiently protects the network because of making up for the weak points in the each demerit. A model has been constructed based on the DEVS (Discrete Event system Specification) formalism for the simulation of the system that consists of IDS and Firewall. With this model we can simulation whether the intrusion detection, which is a core function of IDS, is effectively done under various different conditions. As intrusions become more sophisticated, it is beyond the scope of any one IDS to deal with them. Thus we placed multiple IDS agents in the network where the information helpful for detecting the intrusions is shared among these agents to cope effectively with attackers. If an agent detects intrusions, it transfers attacker's information to a Firewall. Using this mechanism attacker's packets detected by IDS can be prevented from damaging the network.