• The KIPS Transactions:PartD
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• v.12D no.2 s.98
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• pp.289-302
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• 2005

The mobile agent has very various performance according to the element of communication number of times between hosts, quantity of transmission data agent's size, network state etc. specially, migration method is caused much effect in whole performance of distributed system. Most existing migration methods have simplicity structure that it moves doing to accumulate continuously result after achieving task by visiting host in the fixed order. Therefore, in case there are situation such as fault, obstacle, and service absence etc. This can be inefficient due to mobile agent increased network required time. In this paper, we design and implementation Multicast Migration Model for minimizing network required time by solving this problems. Multicast Migration Model includes components such as mobile agent including call module and naming agent, which provides object replication information and distributed server's location transparence. And we evaluate and compare with existing migration method applying prototype system to verify implemented migration model.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.64-75
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• 2007

Service discovery protocols is software components to find specific services or resources on network. The SLP defined by IETF protocol is a framework for automatic service discovery on IP based networks. Automatic service discovery is an important component on ubiquitous computing environment. This paper proposes a service discovery architecture named as SLPA(Service Location Protocol based on AMAAM). AMAAM(Mobility Agent Advertisement Mechanism) is an aggregation-based Mobile IP implementation in MANET. In SLPA, the role of the directory agent is assigned to the mobility agent in AMAAM. The mobility agent periodically beacons an advertisement message which contains both the advertisement of the directory agent in SLP and the advertisement of the mobility agent in Mobile IP. For evaluating the functional correctness of SLPA and the overhead of maintaining a service directory of SLPA. We simulate SLPA using ns-2 and analyze the overhead of control overheads for the aggregation. Through the simulation experiments we show the functional correctness of the proposed architecture and analyze the performance results.

• Journal of Korea Spatial Information System Society
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• v.11 no.4
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• pp.47-55
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• 2009

As the wireless internet technology such as mobile phone, WIBRO, HSDPA develops, customized location-based services for traffic, tourism, shopping, and emergency relief has lately attracted attention. For giving customized services. we should consider dynamic characteristics of moving object which continuously change their location. In this paper, we define the context trigger type of moving object and design triggering method for processing context generated by moving object. Also we propose location-based push service platform including context trigger of moving object for supporting location-based information to user. The proposed system gathers moving object stream from the terminal based on MS-assisted or Stand-alone positioning mode of embedded GPS in terminal extract user context by user device agent, and send context information to server.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.102-108
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• 2015

This paper proposes a new fault isolation methodology for a smart protective device which plays an agent role on the smart grid distribution system with the distributed generation. It, by itself, determines accurately whether its protection zone is fault or not, identifies the fault zone and separates the fault zone through the exchange of fault information such as the current information and the voltage information with other protective devices using bi-directional communication capabilities on the smart grid distribution system. The heuristic rules are obtained from the structure and electrical characteristics determined according to the location of the fault and DG (Distributed Generation) when faults such as single-phase ground fault, phase-to-phase short fault and three-phase short fault occur on the smart grid distribution system with DG.

• Journal of information and communication convergence engineering
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• v.15 no.1
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• pp.37-42
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• 2017

The constrained application protocol (CoAP) can be used for remotely controlling various sensor devices in Internet of Things (IoT) networks. In CoAP, to support the handover of a mobile sensor device, service discovery and message transmission needs to be repeated, although doing so would increase the handover delay significantly. To address this limitation of CoAP, a centralized CoAP scheme has been proposed. However, it tends to result in performance degradation for an inter-domain handover case. In this letter, we propose a distributed CoAP handover scheme to support the inter-domain handover. In the proposed scheme, a distributed mobility agent (DMA) is used for managing the location of mobile sensors in a domain and performing handover control operations with its neighboring DMAs in a distributed manner. A performance comparison reveals that the proposed scheme offers a performance improvement of up to 29.5% in terms of the handover delay.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.217-219
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• 2003

This paper presents a distance relaying algorithm for a transmission line protection with MAS. First, the voltage and fault current of the opposite side are represented as a function of those of the measuring end using source voltages of both ends. These voltages are assumed to be obtained from the transformers protecting agents, periodically in normal state. Then, the fault location expression, independent of fault resistance, is derived with voltage and current in only one end of faulted line used. The suggested algorithm is applied to a simple system with two power sources to show its effectiveness.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.490-492
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• 2003

다중 지역 이동 에이전트 컴퓨팅 환경을 기반하여 이동 에이전트 시스템을 개발하는데 있어서, 이동 에이전트를 관리하고 이동 에이전트들간의 메시지 전달을 보장하기 위한 위치 관리 및 메시지 전달 기법은 중요한 고려사항이다. 그러나 기존이 관련연구들은 여러 지역으로 구성된 다중 지역 이동 에이전트 컴퓨팅 환경에 적용하기에는 위치 갱신 비용 및 메시지 전달 비용이 상대적으로 증가한다는 단점과 추적문제(Following Problem)를 발생시킨다는 한계를 가지고 있다. 이에 본 논문에서는 기존의 홈 프락시 기법과 블랙보드 기법을 변형ㆍ혼합(Hybird)하는 새로운 이동 에이전트 위치 관리 및 메시지 전달 기법인 HB 프로토콜을 제안하고자 한다. HB 프로토콜은 다중 지역 이동 에이전트 컴퓨팅 환경에서 이동 에이전트의 위치 변경시 발생하는 위치 갱신 비용과 이동 에이전트들간의 메시지 전달 비용을 효과적으로 줄이며, 추적문제를 낮은 통신비용으로 해결한다.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.10
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• pp.620-629
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• 2005

In this paper, a new protocol-based approach was proposed for development of a ubiquitous vision system. It is possible to apply the approach by regarding the ubiquitous vision system as a multiagent system. Thus, each vision sensor can be regarded as an agent (vision agent). Each vision agent independently performs exact segmentation for a target by color and motion information, visual tracking for multiple targets in real-time, and location estimation by a simple perspective transform. Matching problem for the identity of a target during handover between vision agents is solved by the Identified Contract Net (ICN) protocol implemented for the protocol-based approach. The protocol-based approach by the ICN protocol is independent of the number of vision agents and moreover the approach doesn't need calibration and overlapped region between vision agents. Therefore, the ICN protocol raises speed, scalability, and modularity of the system. The protocol-based approach was successfully applied for our ubiquitous vision system and operated well through several experiments.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3949-3956
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• 2022

Kori Unit 1 is planning a system decontamination project to reduce radiation exposure of decommissioning workers, prevent the spread of contamination and down-grade the level of classification of radioactive waste. The system decontamination range for Kori Unit 1 will be the entire primary system, including RCS, CVCS and RHRS. Some system design modifications are required for the system decontamination operation. In this paper, major system design modifications were evaluated based on the conditions that system restoration is needed after completion of system decontamination. The major system design modifications are CIDF connection location to system, system decontamination operating pressure control, RCP seal water injection and formation of letdown flow. It was evaluated that there was no negative effect on the system due to the system design modifications. However, as the RCP seal water is injected into the system in the oxidation process, the concentration of the oxidizing agent is diluted. Therefore, the oxidizing agent injection and system decontamination operation procedures should be developed to address the dilution effect of the oxidizing agent. The system design modifications dealt in this paper will be finally confirmed through on-site investigation in the future, and if necessary, the system design modifications will be re-evaluated.

• Journal of Convergence for Information Technology
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• v.9 no.2
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• pp.108-114
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• 2019

In this paper, we propose an intelligent vocabulary recommendation agent that automatically provides vocabulary corresponding to game-based learners' needs and requirements in the mobile education augmented reality game environment. The proposed agent reflects the characteristics of mobile technology and augmented reality technology as much as possible. In addition, this agent includes a vocabulary reasoning module, a single game vocabulary recommendation module, a battle game vocabulary recommendation module, a learning vocabulary list Module, and a thesaurus module. As a result, game-based learners' are generally satisfied. The precision of context vocabulary reasoning and thesaurus is 4.01 and 4.11, respectively, which shows that vocabulary related to situation of game-based learner is extracted. However, In the case of satisfaction, battle game vocabulary(3.86) is relatively low compared to single game vocabulary(3.94) because it recommends vocabulary that can be used jointly among recommendation vocabulary of individual learners.