• 정보와 통신
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• 제25권8호
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• pp.32-38
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• 2008

최근 초고속 인터넷의 급속한 발달로 IP 기반의 방송 및 영상의 분배 기능이 빠르게 개발되고 있다. 과거 아날로그 방송에서는 영상을 변조(scramble) 하여 보내고 대응 복조기를 이용하여 정당한 가입자만 시청 할 수 있도록 하는 기술이다. 하지만 최근 IP 기반의 방송 시스템에서는 과거의 변조 (Scramble) 방식이 한계점을 보이고 있다. IPTV는 방송망과 달리 개방형 특징을 가지고 있다. 이는 인터넷 기반의 다양한 공격(man-in-the-middle-attack, TCP-hijacking)이 IPTV에서도 가능하다는 것이다. 본 고에서는 IP 환경에서 제공 가능한 보안 서비스에 대한 기술을 정리한다. 특히 IPTV서비스를 위한 보안 요구사항, 적용 기술 및 대표적인 연구를 소개한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.150-157
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• 2011

Nowadays, high speed train has settled down as a fast and convenient environment-friendly transportation and it's need is gradually increasing. However increased train speed leads to increased aerodynamic noise, which causes critically affects comfortability of passengers. Especially, the pantograph of high speed train is protruded out of train body, which is the main factor for increased aerodynamic noise. Since aerodynamic noise caused pantograph should be measured in high speed, it is difficult to measure it and to analysis aerodynamic noise characteristics due to the various types of pantograph. In this research, aerodynamic noise of pantograph is predicted by CFD (Computational Fluid Dynamic) and FW-H (Ffowcs Williams-Hawkings) equation. Also, Wind tunnel test results and numerical simulation results were compared. As a result, Simulation results predicting sound pressure level is very similar with wind tunnel test result. This research will draw major factor in aerodynamic noise of pantograph and will be utilized for predict sound pressure level of pantograph.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.249-252
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• 2005

In this paper, we propose a Digital Living Network Alliance (DLNA) proxy system, to provide services for accessing and sharing various DLNA-based media contents which are distributed over his/her or other's home facilities via home network or internet. The proposed system based on DLNA[1] and SIP Notification mechanism[2] so that data such as contents can be transferred from home network consisted with private IP from outside public IP networks.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.1008-1013
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• 2001

KSR-III propulsion system designed in KARI has a gas-pressurization system for propellant feeding system. This system uses a regulator for the control of the ullage pressure of propellant tank and a venturi for passive control of propellant flowrate. This system seems to be very reliable, but the flowrate of propellant varies according to the change of acceleration with the rocket flight. In this paper, dynamic characteristic of KSR-III propulsion feeding system was analyzed in flight condition. The purpose of this research is to find the variation of off ratio and propellant flowrate change for certification condition of engine reliability test.

• 디지털산업정보학회논문지
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• 제6권3호
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• pp.59-68
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• 2010

In the paper, we proposed the Using Correspondent Information for Route Optimization on PMIPv6 over Inter-MAG. Proxy Mobile IPv6 has the problem that a mobile node sends data packets through inefficient routing paths when communicating other mobile node. Route optimization schemes are proposed to solve the triangle routing problem that creates the shortest routing path by leaving the inefficient routing paths. We proposed Correspondent Information Route Optimization scheme to reduce signaling cost as compared with other route optimization scheme. We can reduce signaling cost of route optimization through the Correspondent Information message on basic PMIPv6 and hand-off environment.

• 한국자동차공학회논문집
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• 제6권2호
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• pp.228-234
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• 1998

The buckling is one of the major two nonlinear problems. One is the material non-linearity and other is the geometrical nonlinear. Material non-linearity has occurred when the buckling stress of material exceeded the yield stress of material. The material non-linearity must be taken into account when the buckling analysis of thick plate is performed. In this study, inelastic modulus that is used to calculate the buckling strength is taken to account for the material non-linearity. The results from experiments are used to formulate the semi-theoretical formula. The analysis results generated by the use of semi-theoretical formula are close to the experimental data.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2008년도 추계학술발표회
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• pp.179-180
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• 2008

• 전기학회논문지
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• 제61권10호
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• pp.1420-1425
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• 2012

Nowadays, Interior permanent magnet synchronous motor(IPMSM) which having high power density is much used for the vehicles. However, IPMSM causes a lot of losses because of high-speed driving and high current density, and temperature rising by iron loss and copper loss could reduce torque characteristics and durability of IPMSM. Therefore, analysis about thermal characteristics of IPMSM is required at design stage. In this paper, temperature characteristics according to current vector control method were analyzed through calculate thermal equivalent circuit. And calculated results were verified through comparing with the experiments.

• 전기학회논문지
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• 제59권8호
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• pp.1449-1455
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• 2010

The excitation control system of an emergency diesel generator is classified as a kind of safety-related system. Compared with other control systems in a power plant, this system is required to be more reliable and have better performance. In this paper, the digital multi-redundant excitation system for a diesel generator was proposed. The signal processing system of the proposed system makes high speed signal processing and arithmetic in excitation control possible. The improved soft start algorithm and multiple PI parameters adaptation considering the diesel generator characteristics were implemented in the proposed system. The developed system was applied to a nuclear power plant successfully.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1666_1667
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• 2009

최근 국내 표준 화력발전소는 대부분 초 임계압의 관류형 보일러가 설치되어 운전되고 있다. 보일러 출구 증기온도를 정격치 이내로 운전하는 것은 보일러 운전에 중요한 요소이다. 보일러 효율 상승 등을 고려하여 과열기 Tube 재질의 온도 허용 한계치 이내에서 운전이 되어야 한다. 본 논문은 화력발전소에서 부하변동 범위가 넓고, 고효율 운전이 가능한 초 임계압 관류보일러의 동특성과 과열기 온도제어의 구성 및 실제 운전 중인 발전소의 운전데이터를 분석한 내용에 대하여 기술하고자 한다.