• The KIPS Transactions:PartC
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• v.13C no.2 s.105
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• pp.161-166
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• 2006

In this paper, we propose optical subscriber access network to eliminate multiple access interference using 2 dimensional(D) optical frequency and time domain CDMA method. We have numerically analyzed the characteristics of proposed system. It is seen that the excess intensity noise is the major limiting factor to the system. Also it is seen that the number of simultaneous subscribers is four times as large as the conventional ID optical system under the same bit error ratio.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.734-737
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• 2012

인체 무선망이란 USN(Ubiquitous Sensor Network)을 통해 환자의 생체 정보를 실시간으로 수집하는 환경이다. 이를 기반으로 원격지에서 생체 정보를 전달 받는 시스템이 u-RPMS(USN Remote Patient Monitoring System)이다. u-RPMS에서 실시간으로 환자의 정보들이 발생하는데 이때 실시간으로 발생한 정보들은 공유가 불가피하다. 환자의 생체 정보는 생명과 연결되기 때문에 공유할 때 안전이 중요하다. 하지만 u-RPMS에서는 무선 통신으로 동작하기 때문에 보안에 취약하며, 이를 보안하기 위해서 서버와 DB(Data Base) 사이에 인증 서버를 통해서 해결 할 것을 제시한다. 본 연구에서는 인체 무선망을 기반으로 해서 모듈화 된 오픈 소스 원격진료 플랫폼인 OpenEMed의 개인 확인 서비스(PIDS, Personal Identification Service)를 이용해 네트워크를 기반으로 한 Kerberos 인증을 제안한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.461-463
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• 2018

In this paper, we have studied the devices needed for long distance wireless transmission of SDH network. This devices propose wireless transmission and measurement method of STM-1(basic transmission unit of SDH method) signal and 200Mbps synchronous ethernet. The synchronous clock recovery function is provided for STM-N transmission and synchronous ethernet transmission, and spare clock switching function is designed for stable synchronization. In addition, we discussed the measurement method of STM-N and synchronous Etherent communication method in wireless transmission section.

• The Science & Technology
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• v.33 no.3 s.370
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• pp.66-71
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• 2000

푸른빛을 발산하는 레이저기술이 마침내 한 무명의 과학자(별항참조:무명의 연구가가 완성한 대발명)가 10년간 쏟은 각고의 노력으로 완성되어 세계정보ㆍ통신계에 혁신의 바람을 몰고 오기 시작했다. 2000년 말경에 처음으로 출시될, 푸른 레이저를 이용하는 고화질 DVD 플레이어는 12cm 디스크 양면에 종전의 플레이어보다 2배나 많은 20기가바이트(2백억바이트)의 데이터를 저장할 수 있게 된다. 푸른 레이저는 나아가서 광컴퓨터, 레이저를 이용하는 TV 디스플레이, 무선고속통신장치, 해상도를 두배로 끌어 올릴 수 있는 레이저 프린터 그리고 에너지 효과가 뛰어난 조명등을 포함하여 광범위한 신기술을 창출하여 세상의 모습을 몰라보게 바꿀 것으로 기대된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.450-453
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• 2017

In this abstract, the FPGA system using solar tracking is introduced. Solar tracking system combined with sensor tracking and solar altitude programming is utilized. The sensor tracking system consists of image sensor, light sensor, and the programs for sun altitude received by the computer. The sun altitude is received from the national weather database by wireless communication. The goal is to have maximum energy generation efficiency using bi-directional tracking and mixed tracking with FPGAs that are relatively inexpensive in terms of developing and programming the system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.6
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• pp.150-158
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• 2016

This paper is on a design of a new balise system which has a new functional part of a micro-power inductive wireless loop vehicle detector. The field test has processed and the data has analyzed for check the solar energy operable ability of the detect data interconnect sub-system which includes repeaters and field controllers. Instead of a railroad environment, 12 individual parking-lots are used for field test environment. As a result, in the condition of the designed system and the test environment, it is assumed that under 200 passing vehicles(train or tram) per day can be processed only with solar energy.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.4
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• pp.846-851
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• 2007

The wireless sensor network is one of the most practical and cost-effective solutions for monitoring systems covering wild and wide area such as wildfire monitoring. However, the RF distance between sensor nodes is very short due to the need of low power consumption of the sensor node, so the number of sensor nodes to be deployed in the target area is more than tens of thousands. In this paper, we design and analyze the deployment issues as well as re-deployment problem occurred when the battery is exhausted. We also propose the needs and solutions for coverage problem in dynamic deployment. By the experimental evaluations, we analyze the packet success ratio between sensor nodes under various environments such as obstacles and variable distances.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.188-194
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• 2011

We analyze transmission performance of radio frequency signal in WDM-ROF (wavelength division multiplexing - radio over fiber) system employing photonic crystal fiber. In a WDM-ROF system employing conventional single-mode fiber, transmission performance of radio frequency signal is analyzed depending on each WDM channel. In this case, each WDM channel experiences power fluctuation of received RF signal in remote node because of double sidebands of the modulated signal and wavelength dependent dispersion of single mode fiber. This RF power fluctuation acts as a design constraint in viewpoint of system design. By employing photonic crystal fiber (PCF) with dispersion compensation characteristics, the transmission performance of RF signal can be improved compared with the case with SMF only.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.636-637
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• 2018

The electronic shelf label(ESL) system based on wireless communication can reduce waste of disposable paper, reduce labor force and update real time information. However, the environment in which a large number of ESL modules are installed is exposed to interference from radio frequency(RF) communications in the Industry-Science-Medical(ISM) band. In this paper, we propose an ESL system based on visible light communication to avoid congestion of ESL system using ISM band. In the proposed system, the goods information and ID transmitted from the administrator server are transmitted in the ESL Tag, and the ESL Tag identifies the ID and displays the product information. Experiments show that ESL system using visible light communication is possible.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.748-751
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• 2004

In this paper, we discuss about wireless Internet security. The past few years have seen unprecedented growth in the number of wireless user, applications, and network access technologies. Wireless Internet is similar to wired internet, but it has some constrained wireless environment. So many internet technologies for wireless are developing now. There are WAP(Wireless Application Protocol) and WPKI. WAP(now version 2.0) is a protocol specification for wireless communication networks. it provides an application framework and network protocols for wireless devices such as mobile telephones, PDAs and internet technologies. In this paper some analysis of security(e.g. digital signature or encryption) for wireless internet are performed.