• 한국통신학회논문지
• /
• 제29권12C호
• /
• pp.1707-1721
• /
• 2004

본 논문에서는 네트워크 차원의 종합적인 보안관리가 가능한 침입탐지시스템의 분산 통신모델을 제안하고 보안노드와 분산 시스템 레벨에서 각각 모델링하고 시뮬레이터를 설계하고 구현한다. 노드 레벨에서는 하드웨어기반 침입탐지를 수행하는 기가비트 보안 노드의 구조분석을 기반으로 경보 메시지의 전달 성능을 평가한다. 분산 시스템 레벨에서는 보안정책을 기반으로 네트워크 수준에서 분산 침입방지시스템의 컴포넌트 사이에 전달되는 탐지 및 경보 정보의 전달 성능을 모의실험을 통하여 성능평가를 수행한다. 제안된 모델에서 통신 메커니즘의 결정요인들을 적용하여 성능 평가를 수행하고 시스템의 정량적인 이해를 하기 위하여 결과를 제시한다.

• Journal of international Conference on Electrical Machines and Systems
• /
• 제3권2호
• /
• pp.222-228
• /
• 2014

As tightened the grid connection related regulation for a distributed power generation Japan, islanding of the distributed power generation should be detected more rapidly. In this paper, it is introduced the development tendency of sliding mode frequency shift type anti-islanding technology in Japanese companies.

• Journal of information and communication convergence engineering
• /
• 제8권5호
• /
• pp.473-478
• /
• 2010

Today's engineering design is carried out in a distributed fashion geographically or physically. This places new requirements on the computational environments such as efficient integration and collaboration. With the advances of the Internet and Network environment recently, many researches have been proposed and at the same time, Web-based distributed design gives to a new paradigm in design and manufacturing fields. That is, Web-based technologies lead to reduce the product development times and to ensure a competitive product in order to exchange and interact of real-time design information that integrates the distributed design environment between departments as well as companies via Internet and Web. So, an efficient data communication for design information sharing is the foundation for collaborative systems in the distributed environment. Design data communication techniques such as CORBA, DCOM and RMI have been considered in the existing research but they have some problems that are limitations of interoperability and firewall problems in the Web. Therefore, this paper presents a Web-based distributed design application where distributed design information resources are integrated and exchanged using Web Services for supporting XML and HTTP without the interoperability and firewall problems through the 330K VLCC case.

• Journal of information and communication convergence engineering
• /
• 제1권1호
• /
• pp.12-22
• /
• 2003

Real-time(RT) object-oriented(OO) distributed computing is a form of RT distributed computing realized with a distributed computer system structured in the form of an object network. Several approached proposed in recent years for extending the conventional object structuring scheme to suit RT applications, are briefly reviewed. Then the approach named the TMO (Time-triggered Message-triggered Object) structuring scheme was formulated with the goal of instigating a quantum productivity jump in the design of distributed time triggered simulation. The TMO scheme is intended to facilitate the pursuit of a new paradigm in designing distributed time triggered simulation which is to realize real-time computing with a common and general design style that does not alienate the main-stream computing industry and yet to allow system engineers to confidently produce certifiable distributed time triggered simulation for safety-critical applications. The TMO structuring scheme is a syntactically simple but semantically powerful extension of the conventional object structuring approached and as such, its support tools can be based on various well-established OO programming languages such as C++ and on ubiquitous commercial RT operating system kernels. The Scheme enables a great reduction of the designers efforts in guaranteeing timely service capabilities of application systems

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1982-1985
• /
• 2003

Future cellular networks will mainly be driven by, high quality channels, high band with utilization, low power consumption and efficient network management. For a given channel allocation, the capacity and quality of communication of cellular radio systems using CDMA(Code Division Multiple Access) can be increased by using a transmitter power control scheme to combat the near-far problem. Centralized power control schemes or distributed ones to maximize the minimum signal-to-interference in each user of CDMA wireless network have been investigated. This paper has proposed a distributed power control algorithm, which employs an adaptive search scheme, in order to solve quickly the linear systems of equations for power update in CDMA cellular radio systems. The simulation results show that the proposed scheme has faster convergence rate than the typical bang-bang type of distributed power control algorithm, which has been much used as a reference algorithm in IS-95A and W-CDMA communication network.

• 디지털산업정보학회논문지
• /
• 제14권3호
• /
• pp.39-44
• /
• 2018

Communication in real-time distributed system should have high reliability. To develop group communication Protocol with high reliability, potential fault should be known and when fault occurs, it should be detected and a necessary action should be taken. Existing detection method by Ack and Time-out is not proper for real time system due to load to Ack which is not received. Therefore, group communication messages from real-time distributed processing systems should be communicated to all receiving processors or ignored by the message itself. This paper can make be sure of transmission of reliable message and deadline by suggesting and experimenting fault detection technique applicable in the real time distributed system based on ring, and analyzing its results. The experiment showed that the shorter the cycle of the heartbeat signal, the shorter the time to propagate the fault detection, which is the time for other nodes to detect the failure of the node.

• 한국컴퓨터산업학회논문지
• /
• 제3권8호
• /
• pp.1019-1026
• /
• 2002

이기종 분산환경에서 객체지향기술과 분산기술에 기반한 개방형 정보 통신망 구조의 연구가 진행되고 있다. 객체 그룹화의 목적은 다양하고 복잡한 분산 멀티미디어 서비스를 단순하게 관리하고 서비스를 지원하는데 있다. 본 논문은 이러한 분산 객체그룹 플랫폼 상에 편집자 직접조판을 위한 CTS를 설계한다. 논문의 결과로서 분산CTS 시스템의 기본구조와 객체들 간의 서비스 인터페이스를 설계한다.

• 인터넷정보학회논문지
• /
• 제3권2호
• /
• pp.79-85
• /
• 2002

개방형 통신망 구조에서 어플리케이션 시스템은 다수의 컴퓨팅 노드에 분산되어 있는 객체들의 집합으로 구성된다. 이러한 분산된 환경에서 복잡한 분산 소프트웨어의 개발 및 관리의 복잡성을 줄이고 분산된 객체들을 효율적으로 관리하면서 객체들의 실시간 서비스를 제공하기 위해서는 객체 그룹 관리 및 통신 기법이 필요하다. 본 연구에서는 CORBA를 기반으로 하여 기존의 시스템에 큰 변환 얼이 새로운 서비스를 적용시킬 수 있도록 객체그룹을 구성하고 신뢰성 있는 그룹통신 기법을 제공한다. 그룹관리의 효율향상을 위해 그룹을 서브그룹으로 나누고 서브그룹 관리자를 두어 서브그룹을 관리하도록 하였으며, 시퀀서를 두어 메시지의 순서성을 유지시킨다. 그룹간의 통신방법은 IP 멀티캐스트와 일대일 통신을 기반으로 한 멀티캐스트 기법을 혼용하여 사용하며 메시지 저장소를 두어 오류 발생 시 선택적으로 메시지를 재 전송할 수 있도록 함으로서 성능을 향상시켰다. 제안된 기법을 분산환경에서 시뮬레이션을 통하여 성능을 평가하였다.

• Journal of Positioning, Navigation, and Timing
• /
• 제10권3호
• /
• pp.215-220
• /
• 2021

As the role of robots expands, flexible task planning methods are attracting attention from various domains. Many task planning frameworks are introduced to efficiently work in a wide range of areas. In order to work well in a broad region with multiple robots, various communication conditions should be controlled by task planning frameworks. However, few methods are proposed. In this paper, we propose mission planning methods according to the communication status of robots. The proposed method was verified through experiments assuming different communication states with a multi-robot system.

• 제어로봇시스템학회논문지
• /
• 제16권10호
• /
• pp.1018-1023
• /
• 2010

The CAN (Controller Area Network) system is the most dominant protocol for in-vehicle networking system because it provides bounded transmission delay among ECUs (Electronic Control Units) at data rates between 125Kbps and 1Mbps. And, many automotive companies have chosen the CAN protocol for their in-vehicle networking system such as chassis network system because of its excellent communication characteristics. However, the increasing number of ECUs and the need for more intelligent functions such as ADASs (Advanced Driver Assistance Systems) or IVISs (In-Vehicle Information Systems) require a network with more network capacity and the real-time QoS (Quality-of-Service). As one approach to enhancing the network capacity of a CAN system, this paper introduces a CAN system with dual communication channel. And, this paper presents a distributed message allocation method that allocates messages to the more appropriate channel using forecast traffic of each channel. Finally, an experimental testbed using commercial off-the-shelf microcontrollers with two CAN protocol controllers was used to demonstrate the feasibility of the CAN system with dual communication channel using the distributed message allocation method.