• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1999년도 추계학술대회 논문집
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• pp.127-132
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• 1999

A mobile IP is proposed to support host mobility over the current Internet. One of the most important issues on the host mobility is location and routing schemes that allow mobile hosts to move effectively from one site to another. In a Mobile IP environment, frequent handoffs are likely to degrade the performance by minimizing the loss of datagrams during handoffs. The handoff scheme is using routing optimization and binding extension to improve the performance by minimizing the average transfer delay of messages and packet loss. Simulation details show the improvement of transport delays and packet loss rate.

• 한국통신학회논문지
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• 제27권2C호
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• pp.123-130
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• 2002

셀룰러 망 환경에서 인터넷 호스트의 이동성을 지원하기 위하여, 본 논문에서는 Mobile IP의 단점을 보완할 수 있는 적응적 이동성 제어 방식과 이러한 방식을 구현하기 위한 프로토콜을 제안한다. 본 논문에서 제안한 방식은 사용자의 이동성에 따라 외부 에이전트의 의탁주소를 적응적으로 결정한다. 따라서, 제안된 방식은 외부 도메인의 게이트웨이를 외부 에이전트로 지정하는 기존의 마이크로 이동성 지원 방안들과는 다르다. 이렇게 적응적 방식을 사용하면, 셀룰러 망에서 다양한 환경에 적합한 서비스 품질을 사용자들에게 효과적으로 제공할 수 있다. 또한 핸드오버를 자주 하여 발생하는 Mobile IP의 신호 부하도 줄일 수 있다. 제안된 방식의 성능을 시뮬레이션을 통하여 검토해 본 결과, 이동 노드에게 비교적 안정된 접속점을 제공할 수 있음을 알 수 있었다.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2003년도 춘계학술대회논문집
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• pp.179-184
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• 2003

HLA-RTI is middleware for the distribute simulation that developed in the US Department of Defense. This provides fast accomplishment speed and reliability than distribute simulation Middleware by transfer. However, DDM(Data Distribution Management) service is used as data filtering technology in the existing HLA-RTI. As for this, the problem that network traffic increases in data exchange between the mobility simulation objects is generated. it proposes applying agent technology to the mobility simulation object in order to solve these problems in this paper in this. And this paper applies that to practical simulation and analyzes performance between each data filtering technology with comparison.

• 디지털산업정보학회논문지
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• 제5권3호
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• pp.107-115
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• 2009

Traditionally, simulation method is used to test and evaluate the performance of communication protocol or functional elements for mobile communication service. In this paper, wireless network simulator is implemented using the C++ object-oriented programming language. This simulator can simulate wireless data services, like as ad-hoc networks, by considering the user's mobility. In this paper, the simulator includes network traffic model to reflect wireless data service and traffic source model to represent a user's mobility similar to real service environment and traffic characteristics can be reflected on the simulation, and also more accurate simulation results can be got through that. In addition, by using object-oriented techniques, new service feature or environment can be easily added or changed so that the developed mobile communication simulator can reflect the real service environment all the time. This simulator can be used in adjusting the characteristics of wireless data hosts following the mobility of the user, and also can be used in building new wireless ad-hoc network routing protocols.

• 한국통신학회논문지
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• 제38A권3호
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• pp.258-267
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• 2013

최근 한정된 무선 자원을 효율적으로 사용할 수 있는 이동성 관리 프로토콜로써 Proxy Mobile IPv6(PMIPv6)가 각광을 받고 있다. 그리고 모바일 IPTV 등과 같은 인터넷 방송 시스템의 핵심적인 기술인 멀티캐스트 기술 또한 PMIPv6 네트워크를 중심으로 많은 논의가 이루어지고 있다. 하지만 PMIPv6는 PMIPv6 도메인 내에서의 지역 이동성만을 지원하는 문제점을 가지고 있기 때문에 PMIPv6의 멀티캐스트 서비스에 있어서도 전역 이동을 지원하지 못하는 문제가 존재한다. 뿐만 아니라 지역 간의 이동 시에 발생하는 근본적인 바인딩 절차와 그룹 가입 절차 동안의 패킷 유실을 해결하지 못해 전역 이동에 따른 서비스 끊김 현상이 크게 발생한다. 따라서 본 논문에서는 PMIPv6 네트워크에서 전역 이동을 지원하는 끊김 없는 멀티캐스트 기법을 제안한다. 제안하는 기법은 LMA간 시그널링 추가로 전역 이동이 가능하며 바인딩 절차와 그룹 가입 절차를 고속으로 수행하여 지연시간을 상쇄하였다. 또한 LMA에서 버퍼링 기능을 수행하여 패킷의 손실을 방지하였다. 이와 같은 결과는 시뮬레이션을 통하여 증명하였다.

• 한국수소및신에너지학회논문집
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• 제34권5호
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• pp.478-489
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• 2023

In this study, fault diagnosis and detection methods developed to ensure the reliability of polymer electrolyte membrane (PEM) hydrogen electrolysis systems have been proposed. The proposed method consists of model development and data generation of the PEM hydrogen electrolysis system, and data-driven fault diagnosis learning model development. The developed fault diagnosis learning model describes how to detect and classify faults in the sensors and components of the system.

• 산업공학
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• 제17권1호
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• pp.22-32
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• 2004

The most complicated and difficult area in the simulation of evacuation process is the area of human behavior. However, it is generally very difficult to understand and quantify human behaviors since the factors involved vary significantly according to the types of accidents and the environment. The walking speed of passenger is especially affected by dynamic effect and list due to damage and ship motion in wave. There are various methods to get the useful data for evacuation simulation. The onboard experimental approach is one of the strongest method. This paper discusses the onboard experimental results of human mobility of passengers in evacuation from ship. To realize ship trim and heel due to maritime casuality, the passage model for experiment is made. The experiment was carried out at dynamic and static condition respectively using the ship with passage model. The result was evaluated and it will be reflected in evacuation simulation tool.

• Journal of Communications and Networks
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• 제7권3호
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• pp.377-384
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• 2005

The purpose of this research is to develop and evaluate a traffic engineering architecture that uses local state information. This architecture is applied to an Internet protocol radio access network (RAN) that uses multi-protocol label switching (MPLS) and differentiated services to support mobile hosts. We assume mobility support is provided by a protocol such as the hierarchical mobile Internet protocol. The traffic engineering architecture is router based-meaning that routers on the edges of the network make the decisions onto which paths to place admitted traffic. We propose an algorithm that supports the architecture and uses local network state in order to function. The goal of the architecture is to provide an inexpensive and fast method to reduce network congestion while increasing the quality of service (QoS) level when compared to traditional routing and traffic engineering techniques. We use a number of different mobility scenarios and a mix of different types of traffic to evaluate our architecture and algorithm. We use the network simulator ns-2 as the core of our simulation environment. Around this core we built a system of pre-simulation, during simulation, and post-processing software that enabled us to simulate our traffic engineering architecture with only very minimal changes to the core ns-2 software. Our simulation environment supports a number of different mobility scenarios and a mix of different types of traffic to evaluate our architecture and algorithm.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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• pp.293-296
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• 2001

In this paper, we investigate two soft handover algorithms used in the different mobile communication system. These different systems are IS-95 system and 3GPP system. The performances of two different soft handover are compared under similar conditions in terms of propagation, environment and mobility behavior. For performance comparison of soft handover, we model cell environment, radio channel and mobility. With these models the computer simulation are performed and the result of computer simulation are reported.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.745-748
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• 2003

HLA-RTI는 미국방부에서 개발한 분산 시뮬레이션을 위한 미들웨어로서 이전까지의 분산 시뮬레이션 미들웨어보다 빠른 수행속도와 신뢰성을 제공한다. 그러나 기존의 HLA-RTI에서 데이터 필터링 기술로 사용하는 DDM(Data Distribution Management) 서비스는 이동성이 강한 시뮬레이션 객체들간의 데이터 교환에서 네트웍 트레픽이 증가하는 문제점이 발생하게 된다. 이에 본 논문에서는 이러한 문제점을 해결하기 위해 이동성이 강한 시뮬레이션 객체에 에이전트 기술을 적용할 것을 제안하며 실제적인 시뮬레이션에 적용하여 각 데이터 필터링 기술간의 성능을 비교하고 분석한다.