• Journal of Sensor Science and Technology
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• v.21 no.1
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• pp.46-52
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• 2012

The rapid water pollution in stream, river, lake and sea in recent years raises an urgent need for continuous monitoring and policymaking to conserve the global clean environment. In particular, the increasing water pollution in coastal marine areas adds to the importance of the environmental monitoring systems. In this paper, the mobile server is designed to gathers information of the water quality at coastal areas. The obtained data by the server is transmitted from field servers to the base station via multi-hop communication in wireless sensor network. The information collected includes dissolved oxygen(DO), hydrogen ion exponent(pH), temperature, etc. By the information provided the real-time monitoring of water quality at the coastal marine area. In addition, wireless sensor network-based flooding routing protocol was designed and used to transfer the measured water quality information efficiently. Telosb sensor node is programmed using nesC language in TinyOS platform for small scale wireless sensor network monitoring from a remote server.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.1
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• pp.21-28
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• 2006

This paper describes the design and implementation of video conference system using hybrid type P2P(Peer to Peer). The proposed video conference system has hybrid type P2P architecture based on a client-server and P2P(Peer to Peer), where client-server is used for exchange of account management, client list and status information and P2P is used for the real time video conference. The proposed video conference system decreases the traffic of server, and cuts down the load of a network. Because the multimedia data is decentralized to client by P2P. Also, this system is tested by the multi-party video conference system using communication protocol and application software through high speed networks.

• IE interfaces
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• v.11 no.2
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• pp.39-48
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• 1998

It is strongly believed that Video on Demand(VOD) will become one of the most promising services for Broadband Integrated Services Digital Network(B-ISDN). VOD service can be classified into two types of services: Near VOD(NVOD) and Interactive VOD(IVOD). Although VOD network requires many kinds of resources, we only consider video servers, programs. and storages. In the network. some video servers should be installed at some nodes(especially, at the root node for NVOD service). so that each node with video server stores video programs and distributes stored programs to customers. We take into account three kinds of costs related with the above resources: a program transmission cost, a program storage cost, and a video server installation cost. There exists a trade-off relationship among those three costs according to the locations of video servers and the kinds of programs stored at each video server. Given a multi-level VOD network and the total number of programs being served in the network. the resource. optimization problem for providing both IVOD and NVOD services is to determine where to install video servers, and which and how many programs should be stored at each video server, in order to minimize the total cost. In this paper we develop an efficient dynamic programming algorithm to solve the problem. We also implement the algorithm based on two different service policies assumed in this paper.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.4
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• pp.3-11
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• 2003

It is very important to detect and remove original sources of various attacks through networks. One of the effective method to detect the sources is traceback systems. In this paper, we design and implement an agent-based traceback system that does not require the reaction of routers and administrators and does not need numerous log data. In the design, we introduce a traceback server and traceback agents in each network Using sniffing and spoofing, the server transmits a packet with a specific message. The agents detect the packet and provide the information for the server to trace back the original source.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.665-666
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• 2015

Recently BIM technology has been expanded for using in construction project. However its spread has been delayed than the initial expectations, due to the high-cost of BIM infrastructure development, the lack of regulations, the lack of process and so forth. In construction site phase, especially the analysis of current research trend about IT technologies, virtualization and BIM service, data exchange such as drawing, 3D model, object data, properties using cloud computing and virtual server system is defined as a most successful solution. The purpose of this study is enable the cloud computing BIM server to provide several main function such as edit a model, 3D model viewer and checker, mark-up, snapshot in high-performance quality by proper design of VDI system. Concurrent client connection performance is a main technical index of VDI. Through test-bed server client, developed VDI system's multi-connect control will be evaluated. The performance-test result of BIM server VDI will effect to development direction of cloud computing BIM service for commercialization.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.05a
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• pp.183-187
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• 2002

JLBS는 multi-server multi-queue 방식을 채택하고 있으며, 각 tool별로 할당된 license 수에 비례하여 system을 할당한다. 그러나 이러한 방식의 문제점은 특정 tool에만 job이 집중될 경우 비효율적이다. 즉 특정 system은 모두 사용되고 있고, queue에는 많은 job이 대기하고, 여타 tool에 해당하는 queue에는 대기하는 job이 없어서 system이 그냥 놀고 있는 현상이 발생한다. 본 논문에서는 이러한 단점을 극복하기 위해 각 tool에 license수에 비례하여 할당되었던 system을 모든 tool들이 system을 공유할 수 있도록 하는 방법을 제안했다. 대신 system의 숫자는 줄이고, license의 숫자는 더 할당하는 방법으로, 기존의 방법보다 더 효율적으로 나타났다.

• Proceedings of KOSOMES biannual meeting
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• 1999.03a
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• pp.7-17
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• 1999

This paper describes design techniques on the ship simulator system adopting virtual reality technology. Ship handling, generally, is done by the multi workers such as Captain, Officer, Pilot and Quartermaster. With this special fact, we proposed multi client-server network and hardware architecture which fit to the Virtual Reality Ship Simulator.

• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.6
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• pp.299-305
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• 2020

We have developed a scheduler that additionally consider network performance by extending the Kubernetes developed to manage lots of containers in cloud computing nodes. The network delay adapt characteristics of the compute nodes were learned during server operation and the learned results were utilized to develop placement algorithm by considering the existing measurement units, CPU, memory, and volume together, and it was confirmed that the low delay network service was provided through placement algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1675-1678
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• 2004

In this paper, web based monitoring systems are implemented for multi-axis force control systems of an intelligence robot. A brief review about the principle of multi-axis force sensors and a method that can reduce the effect of noise signal to sensor performance is presented. A web based monitoring system is implemented by porting Linux at embedded systems which include Xscale processors. A device driver is developed to receive data from multi-axis force sensors in Linux operation systems. To control this device driver, a socket program for web browser is also developed. The experiments are performed to investigate the effectiveness of proposed methods. The experimental results show that the values of force sensors can be monitored by remote PCs.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.4
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• pp.334-340
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• 2004

In this paper, a Web-based management system for the building network is described. A multi-protocol converter based on SoC and embedded Linux is designed. The open source licensing, reliability, and broad hardware support are key reasons for use of embedded Linux in embedded industry. The multi-protocol converter integrates control network of RS-485 and LonWorks devices through TCP/IP protocol for a client with Java applet. The system consists of three-tier architecture, such as a client, a server that is performed on a multi-protocol converter, and control devices. The developed system includes the inverter motor control system with modbus protocol for the RS-485 network. The experiment results show that the multi-protocol converter using embedded Linux is a flexible and effective way to builda Web -based monitoring and control system.