• 한국정밀공학회지
• /
• 제16권1호통권94호
• /
• pp.161-166
• /
• 1999

Virtual Manufacturing System(VMS) is a computer model that represents the precise and whole structure of manufacturing systems and simulates their physical and logical behavior in operation. In this paper, a real time simulation for the virtual factory is proposed to integrate a process planning with scheduling under distributed environments. In order to communicate the information under distributed environments, we use a server/client concept using socket program and internet.

• 한국경영과학회지
• /
• 제22권2호
• /
• pp.31-44
• /
• 1997

This paper presents an approximate analytical model to estimate the mean packet walting times at the stations in the IEEE 802, 6 subnetwork of a metropolitan area network. Each station is modeled as a two queue single server system, which serves data packets and requests from downstream stations according to the DQDB protocol. The model estimates the mean waiting time of the requests and in turn, using the discrete time work conservation law, estimates the mean waiting time for packets. Simulation experiments shows that the model accurately works even under very high traffic loads.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1999년도 추계종합학술대회 논문집
• /
• pp.939-942
• /
• 1999

In this paper, Tele-Test System for ASIC Design is constructed. It consists of the server, and the clients. The server and clients are implemented by Java. Using Java RMI system, the remote access via information network is implemented. In this Tele-test system, fault simulation, test pattern compaction, test pattern generation, and path-delay fault test generation services are implemented. All service can be peformed parallel by network access.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 1999년도 가을 학술발표논문집 Vol.26 No.2 (3)
• /
• pp.105-107
• /
• 1999

최근 컴퓨터와 제반 기술들의 눈부신 발달로 인해 대용량의 멀티미디어 데이터를 다루는 서비스들이 많이 등장하고 있다. 주문형 비디오 서비스(Video on Demand)가 가장 대표적인 예라고 할 수 있으며, 이를 구현하기 위한 많은 방법들이 제안되고 있다. 본 논문에서는 현재까지 개발되어 있는 VoD 시스템에 관하여 살펴보고, 이를 기반으로 PASS(Parallel and Scalable Server) VoD 시스템을 제안한다. PASS VoD 시스템은 병렬 비디오 서버로서 SAN(System Area Network)로 연결된 independent proxy 구조와 비슷한 구조를 가지는 시스템이다. 본 논문에서는 PASS VoD 시스템에 대하여 설명하고 PASS VoD 시스템이 scalable 함을 시뮬레이션을 통하여 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제7권4호
• /
• pp.784-799
• /
• 2013

This paper presents an adaptive rate control scheme for streaming-based content sharing service. This scheme delivers multimedia contents from a user device to another device or seamlessly redirects streaming service across heterogeneous user devices. In the proposed scheme, a streaming server adjusts video quality level according to the network and client status. Our scheme is different from other rate control schemes, because the video quality at the server is decided not only based on the available bandwidth, but also based on the device characteristics and bandwidth requirement at the access network. We also propose a bandwidth estimation method to achieve more equitable bandwidth allocations among streaming flows competing for the same narrow link with different Round Trip Times (RTTs). Through the simulation, we prove that our scheme improves the network stability and the quality of streaming service by appropriately adjusting the quality of the video stream. The simulation results also demonstrate the ability of the proposed scheme in ensuring RTT-fairness while remaining throughput efficient.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2011년도 제42회 하계학술대회
• /
• pp.370-371
• /
• 2011

This paper proposed an under-voltage relay algorithm module for a network based protective relay simulator. The simulation system is based on the client-server paradigm. The relaying simulator which consists of server-side relay models and user interface provides network-based simulation environment for a variety of protective relaying algorithms. The performance of the relay algorithm was verified by comparing the results of under-voltage relay algorithm in the simulator with the results of the C language implementation.

• 한국정보처리학회논문지
• /
• 제7권4호
• /
• pp.1279-1289
• /
• 2000

Recently, research activities for combining portable computer technology and wireless communication technology are in progress to realize mobile computing environment that designed to support mobile hosts in the existing network environments. For PCN environments, the location management strategies are particularly emphasized among various strategies necessary for the mobile computing environment. Location management strategy for PCN environment, which is mostly based on the IS-41 standards brings an issue that additional network traffics are generated to deliver updata messages to home location server whenever a mobile host changes its location server. In this paper, we propose an innovative updata strategy and a search strategy that resolves the problem shown in the IS-41 scheme for HLR/VLR structure of CDMA environments. Also, this paper presents the performance comparison of proposed scheme and scheme used in IS-41 obtained from a simulation. The simulation was conducted based on the number of messages, the rate of database accesses, and the number of hops visited when the location management scheme is executed.

• 한국시뮬레이션학회:학술대회논문집
• /
• 한국시뮬레이션학회 1998년도 추계학술대회 및 정기총회
• /
• pp.6-6
• /
• 1998

본 논문에서는 WDM(Wavelength Division Multiplexing) 수동 성형망(Passive Star Network)에서 클라이언트/서버 트래픽을 위한 효율적인 TDM(Time Division Multiplexing) 스케쥴링 알고리즘을 소개하고 알고리즘의 성능분석 및 단대단 트래픽의 지연분석 결과를 소개한다. 클라이언트/서버 트래픽은 서버 노드와 클라이언트간의 송, 수신 트래픽 양이 클라이언트 노드간의 트래픽 양에 비해 상대적으로 크기 때문에 TT-FR 시스템의 TDM 시스템 기반으로 클라이언트/서버 트래픽의 특성을 효율적으로 이용하는 새로운 TDM 스케쥴링 방법으로 STFA(Server Traffic Frist Assignment) 알고리즘을 제시하고 성능 분석결과를 나타낸다. STFA 알고리즘은 서버 노드의 송신 및 수신에 각각 하나씩의 파장을 먼저 할당함으로써 클라이언트 노드는 송, 수신 모두를 위해 파장 조정이 요구되는 방법이다. STFA 알고리즘이 TT-FR 시스템의 TDM 스케쥴링 방법보다 짧은 프레임 길이를 제공함을 정적인(STatic) 트래픽 수요에 대해 보였으며 동적인(Dynamic) 트래픽 수요에 대해 단대단 트래픽의 지연분석 결과를 나타내었다. 이를 위해 다양한 시뮬레이션을 수행하였다.

• 한국시뮬레이션학회:학술대회논문집
• /
• 한국시뮬레이션학회 2005년도 추계학술대회 및 정기총회
• /
• pp.19-24
• /
• 2005

Radio Frequency Identification (RFID) is a technology used to identify the physical objects and get information about the object on which the tag attaches from network. It is expected that RFID will lead IT market from human-oriented to object-oriented. Therefore, RFID technology and services will become wide-spread. But the system of RFID naming service is quite similar to the existing DNS facilities. So it has many weak points against to DDos attack. Furthermore if the MDS server Is under attack, there might be trouble of total RFID networks.In this paper, we propose a new detecting model to find attack traffic at local routers by using Management Information Base (MIB) which is optimized for RFID MDS server.

• 한국멀티미디어학회논문지
• /
• 제20권1호
• /
• pp.51-57
• /
• 2017

The purpose of this study is to design a system that can be used for military simulation and virtual training using the location information of individual soldier's weapons. After acquiring the location information using Arduino's GPS shield, it is designed to transmit data to the Smartphone using Bluetooth Shield, and transmit the data to the server using 3G/4G of Smartphone in real time. The server builds the system to measure, analyze and manage the current position and the tracking information of soldier. Using this proposed system makes it easier to analyze the training situation for individual soldiers and expect better training results.