• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.290-290
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• 2004

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.493-495
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• 2003

유선 네트워크에서의 토큰 패싱 LAN 접근 제어 방식을 무선 네트워크에 적용하면 네트워크의 높은 부하 상황에서도 안정된 성능을 보인다. 본 논문에서는 실시간 트래픽 서비스와 비실시간 트래픽 서비스가 공존하는 인터넷에서 서비스의 질을 지원하는 무선 토큰링 프로토롤을 제안하였다 제안된 프로토콜 메커니즘에서는 실시간 트래픽 서비스 노드에겐 비실시간 트래픽 서비스 노드보다 토큰 수신을 우선적으로서 부여함으로 빠른 전송을 지원하며, 기존의 토큰 전송 방식에 QoS를 지원하는 장점을 가진다.

• ETRI Journal
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• v.43 no.3
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• pp.471-482
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• 2021

Several code-division multiple access (CDMA)-based interconnect schemes have been recently proposed as alternatives to the conventional time-division multiplexing bus in multicore systems-on-chip. CDMA systems with a dynamic assignment of spreading codewords are particularly attractive because of their potential for higher bandwidth efficiency compared with the systems in which the codewords are statically assigned to processing elements. In this paper, we propose a novel distributed arbitration scheme for dynamic CDMA-bus-based systems, which solves the complexity and scalability issues associated with commonly used centralized arbitration schemes. The proposed arbitration unit is decomposed into multiple simple arbitration elements, which are connected in a ring. The arbitration ring implements a token-passing algorithm, which both resolves destination conflicts and assigns the codewords to processing elements. Simulation results show that the throughput reduction in an optimally configured dynamic CDMA bus due to arbitration-related overheads does not exceed 5%.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.2
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• pp.268-275
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• 2020

A lightweight hardware design of self-timed ring based true random number generator (TRNG) suitable for information security applications is described. To reduce hardware complexity of TRNG, an entropy extractor with feedback structure was proposed, which minimizes the number of ring stages. The number of ring stages of the FSTR-TRNG was determined to be a multiple of eleven, taking into account operating clock frequency and entropy extraction circuit, and the ratio of tokens to bubbles was determined to operate in evenly-spaced mode. The hardware operation of FSTR-TRNG was verified by FPGA implementation. A set of statistical randomness tests defined by NIST 800-22 were performed by extracting 20 million bits of binary sequences generated by FSTR-TRNG, and all of the fifteen test items were found to meet the criteria. The FSTR-TRNG occupied 46 slices of Spartan-6 FPGA device, and it was implemented with about 2,500 gate equivalents (GEs) when synthesized in 180 nm CMOS standard cell library.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.2
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• pp.160-170
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• 1988

This paper describes the outboard NIU(Network Interface Unit) using microprocessor and the hardware and software of concentrator for constructing star typed LAN(Local Area Network) based on token ring method. The NIU adapter can adapter up to four parallel and serial typed terminals. Because it has PAD function on input output data, any type of terminals can be adapted. Since the concentrator has logical switching circuit which enables data to bypass the faulted NIU adapter, this network prevents communication break. When user transmits and receives data, the concentrator constructs star typed LAN which connct both transmitting and receiving sides. A s result, this network eliminated ring latency time in other NIU exculding transmitting and receiving NIU. So the throughput of this LAN is increased. Because this LAN system consists of several modultes according to it's function, the expansion of function or the modification of method is easy.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1767-1770
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• 2003

This paper proposes an efficient network architecture for reflective memory system (RMS). Using this architecture, the time for broadcasting a shared-data to all nodes can be significantly shortened. The device named topology conversion switch (TCS) is implemented to realize the network architecture. The implemented TCS is applied to the ethernet based real time control network (ERCnet) to evaluate the performance.

• 전기의세계
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• v.38 no.6
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• pp.50-57
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• 1989

고속전철 시스템을 완성하는데 있어 일반적인 경우 전원공급 시스템(power supply system), ROollingstock 및 토목공사분야등이 중요시 되고 있다. 그러나 고속으로 운행되는 전철시스템이 정상적으로 운행되고 특히 인원의 안전을 보장하기 위해서는 통신 및 신호시스템의 중요함이 간과되어서는 안된다. 내부통신네트워크는 Trainset 자체가 정상적인 운행이 되도록 만들어 주는 신경역할을 하는 것으로 주로 컴퓨터 네트워크의 개념으로 접근하여야 하며 확장성, 가용성, 견고성 등이 고려요소가 된다. 특히, 확장성과 가용성의 측면에서 Token-ring아키텍쳐가 우선적으로 고려될 수 있음을 보았다. 네트워크에 접속되는 프로세서 및 터미날은 전체 시스템중 뇌(Brain)의 역할을 수행하는 것으로 마이크로 프로세서 개념으로 발전되어야 할 것이다. 원거리통신 네트워크는 전철과 지상설비간의 통신계통으로 요구되는 데이타의 형태, 량 및 전송속도에 따라 설계되어야 한다. 원거리 통신네트워크의 일부인 무선시스템은 고속주행시스템의 특성이 고려되어야 한다. 최근 급속히 발전되고 있는 셀룰라시스템의 개념을 적용할 수 있을 것이다. 특히 디지탈 세룰라의 실용화가 눈앞에 보이기 때문이다.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.659-665
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• 2013

IPCS(Inter Process Communication Service) is a real-time communication middleware designed for warship combat battle systems based on publisher-subscriber communication model. Because IPCS was originally designed to operated under 100 Mbps network environment, increasing network speed into Gigabit environment does not linearly increase the throughput of IPCS. To solve this problem, we anaylized IPCS structure and optimized IPCS into Gigabit-Ethernet environment. We found parameters to improve IPCS based on UDP and Token-ring structure. By improving, IPCS has reliability and higher throughput than TCP although IPCS is based on UDP.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.667-669
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• 2002

IEEE 802.1x는 LAN(Local Area network) 환경에서의 인증을 위해서 IEEE에서 제안한 인증 표준 프로토콜이다 IEEE 802.1x는 token ring, FDDI(Fiber Distributed-Data Interrace), 802.3 등 다양한 802 표준에서 동작할 수 있도록 고안되었다 802.1x는 supplicant와 Authenticator, Authentication Server로 구성된다. 이러한 802.1x의 LAN 환경에서 QoS(Quality of Service)를 보장하기 위해서는 자원 예약 메커니즘이 필요하다. 이러한 자원 예약 메커니즘으로는 RSVP(Resource Resonation Protocol)가 있는데 이것은 유선 네트워크를 위해 설계되었기 때문에 새롭게 수정이 불가피하다. 본 논문에서는 RSVP를 수정 보완하여 WLAN(Wireless LAN)에 맞는 시그널링 프로토콜을 제안한다. 제안한 시그널링 프로토콜을 이용하여 WLAN 에서의 QoS 문제를 해결한다.

• Journal of the Korea Society for Simulation
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• v.3 no.1
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• pp.115-124
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• 1994

In this paper, we have developed a performance analysis tool for communication networks called COMNAS. COMNAS analyses the performance of wide area networks such as Korea Educational Network and Korea Research Environment Open Network which include local area networks such as Ethernet and Token Ring. COMNAS consists of model constructor, simulation implementor, output analyzer and user interface. Attributes of communication networks for modeling either have default values or are entered by user as object units, and implementation of simulation is automatically proceeded by user interface. Ouput results obtained by COMNAS are the status of node, link and entire network such as mean message transmission delay, throughput, utilization, and so on, and they can be selectively obtained upon the request of the user.