• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.2
• /
• pp.260-268
• /
• 2008

This raper discusses improvement of MCVoD System by changing the channel allocation of VoD Server. And we analyzed performance of MCVoD System. Using simulation, we compare MCVoD with another VoD server using same channel allocation. In case of average channel allocation, MCVoD System using interchange agent, represents three times better than previous VoD server.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2003.11a
• /
• pp.153-157
• /
• 2003

전력연구원에서는 울진 표준형원전의 시뮬레이터를 개발하였으며, 여기에는 가상 주제어실, 발전소 현상 감시, 중대사고 등 많은 클라이언트 프로그램들이 있다. 이러한 프로그램들은 시뮬레이터와 연동되어 필요한 값을 읽고 쓰는 과정이 필요하다. 그러나 현재는 해당 시뮬레이터 환경에서 개발되지 않는 외부의 응용프로그램이 이들 시뮬레이터의 값들을 엑세스하는 방법은 제공하지 않고 있다. 본 보고서에서는 이러한 문제점을 해결하기 위해 외부 프로그램들이 시뮬레이션모델의 각종 변수들을 효과적으로 엑세스하여 값을 Read/write 할 수 있는 OPC (OLE for Process Control) Server를 개발하였다. 본 프로그램은 Rockwell의 OPC Server Toolkit인 RSI OPC/DDE Server Toolkit Library를 이용하여 개발하였으며 시뮬레이터가 실행되고 있는 컴퓨터에서 실행된다. 본 보고서에서는 OPC 일반개념, 개발한 OPC Server의 소개, OPC Server의 적용결과 등을 기술하고자 한다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.11
• /
• pp.1546-1549
• /
• 2020

This paper introduces the development process of mobile home CCTV that enables remote control and object recognition using unused smartphones and Arduino. Clients can control motors connected to Arduino through button, enable bidirectional voice communication between client-server and receive video from the server in real time. The server sends a PUSH notification to the client when its battery is low. When the server recognizes the charger, the client's remote control allows the server to dock to the charger and charge it. It was confirmed that video and voice delivery between client and server works well without any problems, and that object recognition works smoothly.

• Journal of Industrial Technology
• /
• v.21 no.A
• /
• pp.129-134
• /
• 2001

Linux cluster Server makes a high performance PC cluster system, and provides scalablity and availability as compared with an expensive single server. In this paper, we design and implement a VOD streaming service system to serve video and audio streaming services on the Linux cluster server. Our Streaming server supports the MS Window Media Format based on the RTSP streaming protocol.

• Journal of the Korean Data and Information Science Society
• /
• v.17 no.1
• /
• pp.13-18
• /
• 2006

The purpose of this paper is to identify optimal designs of server port connections between two server system for 200-300 user group. Given 3 empirical models as user and port parallel server types under some conditions of 100 Mbps and optimal CPU temperature suggested by Lee and Kim(2005), our results are shown; port parallel model was optimal when traffic processing times measured, and 250 traffics was jumping point as a critical point in our cases.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2004.05b
• /
• pp.755-759
• /
• 2004

인터넷의 확산으로 인해 가정의 정보화 필요성이 급증함에 따라 Home Network를 위한 Home Server의 개발이 요구되고 있다. 이에 본 논문에서는 가정에서 손쉽게 Home Network를 구축할 수 있는 Home Server를 개발함으로써 가정 정보화에 기여하고자 한다.

• Journal of KIISE:Information Networking
• /
• v.33 no.3
• /
• pp.231-246
• /
• 2006

A server load balancer is used to accept and distribute client requests to one of servers in a wireless internet proxy server cluster. LVS(Linux Virtual Server), a software based server load balancer, can support several load balancing algorithms where client requests are distributed to servers in a round robin way, in a hashing-based way or in a way to assign first to the server with the least number of its concurrent connections to LVS. An improved load balancing algorithm to consider server performance was proposed where they check upper and lower limits of concurrent connection numbers to be allowed within each maximum server performance in advance and apply the static limits to load balancing. However, they do not apply run-time server load information dynamically to load balancing. In this paper, we propose a dynamic load balancing scheme where the load balancer keeps each server CPU load information at run time and assigns a new client request first to the server with the lowest load. Using a cluster consisting of 16 PCs, we performed experiments with static content(image and HTML). Compared to the existing schemes, experimental results show performance improvement in the cases of client requests requiring CPU-intensive processing and a cluster consisting of servers with difference performance.

• Proceedings of the IEEK Conference
• /
• 2002.07a
• /
• pp.238-241
• /
• 2002

With the popularity of utilization of the Internet among people, the amount of data in the network rapidly increased. So that, the fall of response time from WWW server, which is caused by the network traffic and the burden on m server, has become more of an issue. This problem is encouraged the rearch by redundancy of requesting the same pages by many people, even though they browse the same the ones. To reduce these redundancy, WWW cache server is used commonly in order to store m page data and reuse them. However, the technical uses of WWW cache that different from CPU and Disk cache, is known for its difficulty of improving the cache hit rate. Consecuently, it is difficult to choose effective WWW data to be stored from all data flowing through the WWW cache server. On the other hand, there are room for improvement in commonly used cache replacement algorithms by WWW cache server. In our study, we try to realize a WWW cache server that stresses on the improvement of the stresses of response time. To this end, we propose the new cache replacement algorithm by focusing on the utilizable information of network distance from the WWW cache server to WWW server that possessing the page data of the user requesting.

• Journal of Korea Spatial Information System Society
• /
• v.6 no.1 s.11
• /
• pp.87-100
• /
• 2004

When spatial data which a user requests are stored various data servers in web mapping environment, it is necessary to access one more map servers to gain data and then integrate them. This paper designs and implements a fusion map server for web mapping. The proposed fusion map server has three characteristics. First, it has customizing metadata which reflect various user's requests. Second, it provides fusion services which integrate spatial and non-spatial data. Last, it uses the dynamic liking method to support the fusion services efficiently. We design and implement a publisher client, a map server and a fusion map server for proposed map server.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.5 no.7
• /
• pp.1361-1373
• /
• 2001

In the firewall systems of 3-tier client/server systems, in general, data transmission speed is declined rapidly according to the duplicated proxy services in application server and fire wall server. In this paper, an application server configuration containing the proxy functions of firewall system is proposed so that the high speed data transmission can be achieved. The proposed application server can form the dual-homed gateway by means of the additional network interface card. The screened router of application server forms the screened subnet gateway that can separate the internal network. The proposed server configuration is more effective in traffic control than the traditional firewall systems and provides high speed data transmission with the functions of firewall. It can be also cost-effective alternative to the firewall system.