• Journal of Digital Contents Society
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• v.13 no.2
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• pp.151-157
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• 2012

Even though the protective facility is well made with the development of medicine, the spatial dose within the radiation section could increase the exposure of the workers. The spatial dose is always present in distribution room within the Department of Nuclear Medicine, so the spatial dose of the interior distribution room is measured and analyzed for the prediction of the exposure dose. The spatial dose rate was $6.78{\pm}0.083{\mu}Sv/h$ in the $^{18}F$ distribution room of department of Nuclear Medicine, $9.248{\pm}0.013{\mu}Sv/h$ in $^{99m}Tc$, and $^{131}I$ distribution room. In addition, in case of $^{18}F$ distribution room, the yearly external exposure dose was $42.5{\mu}Sv$ when the nurse does IV in 1m in distance. It also showed that the spatial dose rate on the direction of right oblique showed higher than others by the standard of distribution window of distribution room. Therefore, the staying time of the workers should be short during distributing radiopharmaceuticals in the distribution room and the design of the distribution protection is necessary to reduce the exposure in the direction of right oblique of the protection. The utmost endeavors are required to reduce the worker's individual exposure dose while doing IV.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2012.05a
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• pp.367-368
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• 2012

• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.448-450
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• 2004

센서 네트워크는 다양한 탐지 대상 및 환경을 감시하는데 유용하게 사용될 수 있다 이러한 센서 네트워크에서 센서 노드간 키를 설립하는 것은 보안을 위한 가장 기본적인 요구 사항이다 하지만 센서가 가진 기본 특성인 자원의 제약 때문에 일반 네트워크에서 사용되고 있는 중앙 키 분배 서버를 이용한 키 분배나 공개키 기법을 사용하는 것은 적합하지 않다. 따라서 본 논문에서는 센서 네트워크 특성에 맞는 키의 사전 분배 방식을 제안한다. 본 논문에서 제시한 기법은 클러스터를 기반으로 위치 정보를 이용하여 키를 사전 분배하였기 때문 에 노드간 키 설립확률을 높였을 뿐만 아니라, 악의적인 노드에 의해 다항식이 공개되어 정상 노드가 붕괴되는 것을 막기 위해 클러스터당 헤드를 두어 다항식을 공유하는 노드의 범위를 줄여 보안을 보다 강화 시켰다.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.859-864
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• 2000

This paper reports a numerical flow characteristic analysis in gas boiler combustion chamber. The numerical results with simplification and assumptions were found within 30% of the experiment. A lot of geometrical modification has been invested in attempt to obtain the uniform flow in the combustion chamber exit. As a result, the velocity magnitude of the combustion chamber is relate with the hole size in air distribution plate. The velocity uniformity of the combustion chamber is relate with the number of holes and location in air distribution plate.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.8
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• pp.21-31
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• 1998

In this paper, a new algorithm is proposed which distributes multicast cells in a copy network. The dual copy network is composed of running adder network, distributor, dummy address encoder, and broadcasting network. It is operated lower input address and higher one simultaneously by the distribution algorithm. As a result, for each input has a better equal opportunity of processing, cell delay and hardware complexity are reduced in copy network. Also, for it adopts the broadcasting network from an expansion Banyan network with binary tree and Banyan network, overflow probability is reduced to a half in that network. As a result of computer simulation, the copy network processed by the distribution algorithm is remarkably improved in cell delay of input buffer according to all input loads.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.781-786
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• 2017

This study aims to acquire a basic clustering technology of hybrid rocket motor for lunar lander, including the oxidizer flow distribution characteristic and the simultaneous ignition characteristic. The experimental setups were established to conduct a series of ground firing test of a clustered motor. The gaseous oxygen (GOX) and the HDPE (High Density PolyEthylene) were used as the oxidizer and the solid fuel, respectively. Experimental results which are the simultaneous pyrotechnic ignition characteristic, the oxidizer distribution characteristic and the pressure traces of each combustion chamber imply that the hybrid rocket clustered motor works successfully.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1260-1262
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• 2010

IPTV 는 대표적인 방송통신융합 산업으로 IT 망의 양방향성을 이용한 서비스의 차별화를 내세우며 여러 사업자에 의해 서비스가 이루어지고 있다. 기존 유선 통신망을 중심으로 제공되어 왔던 IPTV 서비스는 최근 모바일 환경 등으로 그 영역을 확대하기 위해 연구가 진행되고 있으며, 다른 한편으로는 IPTV 서비스를 위한 플랫폼 등을 개방하여 사업자가 아닌 일반인도 IPTV 를 통한 방송을 할 수 있는 구조인 Open IPTV 에 대한 연구가 활발하다. 이러한 Open IPTV 환경에서는 다수의 컨텐츠 제공자가 존재하기 때문에 기존 IPTV 에서 사용 되는 특정 기기 혹은 스마트카드를 통한 사용자 인증 및 키 분배가 어려운 실정이다. 따라서 본 논문에서는 Open IPTV 환경에서 안전한 컨텐츠 전송을 위한 사용자 인증 및 키 분배 시스템을 제안하고자 한다.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.6 no.1
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• pp.28-36
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• 1995

In this paper, a design method of multiple n-way low loss power divider for x-band is propossed. To decrease loss, only two-stages of transmission lines are used with isolation resistors for match. Ex- perimental results for 3-way and 4-way power dividers have the divided power of 5.54~6.17dB and 6.76~7.37 dB, the return loss of more than 17dB and 12dB, and the isolation of more than 18dB and 10dB at center frequency, respectively, The measured results show good agreement with the theoretical analysis.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.4
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• pp.73-79
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• 2015

Enhanced bandwidths of the GPS microstrip patch antennas applied by a Wilkinson power divider and a quadrature hybrid were compared. The square patch was designed, and fed by the two port probes for the circuit application. The Wilkinson power divider and quadrature hybrid circuit were designed, and applied to the patch antenna. The designed patch and two circuits were implemented on the FR4 board, and combined together. The measurement of the bandwidth within a voltage standing wave ratio (VSWR) of 2: 1 were 36.5% (1,200~1,775 MHz) in the case of the Wilkinson power divider and 29.84% (1,230~1,700 MHz) in the case of the quadrature hybrid. Axial ratios (AR) in 3dB were 17.14% bandwidth (1,360~1,630 MHz) and 15.87% bandwidth (1,400~1,650 MHz), respectively. The application of the Wilkinson power divider is wider than that of the quadrature hybrid. The peak gains in the anechoic chamber at the GPS center frequency were measured as 2.84 dBi and 2.75 dBi, respectively.

• KSBB Journal
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• v.9 no.3
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• pp.279-286
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• 1994

A mathematical model has been derived and used to describe phosphoprotein partitioning in Fe(III) IDA-PEG/dextran two-phase systems. This model includes the inhibitory effects of hydrogen and hydroxyl ion concentrations on protein partitioning. For aqueous two-phase partitioning experiments, the Al and A2 subcomponents of ovalbumin carrying two and one surface phosphoryl group(s) were purified using an immobilized metal ion affinity chromatography (IMAC). The ratio of partition coefficients in the presence and absence of Fe(III)IDA-PEG, K/Ko, increased in the pH range of 3.0 to 5.0 due to deprotonation of the second oxygen of the phosphoryl group, and above pH 5.0 declined steeply by the inhibitory binding of hydroxyl ions to the metal ion. This partitioning behavior was well described by the mathematical model. The binding constants for formation of the complex between the phosphoryl group and the Fe(III)IDA-PEG were found to be $6.1{\times}10^3M^{-1} and 2.3{\times}10^4M^{-1}$ in the top and bottom phases, respectively. These values are 3-5 times those for interaction of Cu(II)IDA-PEG with a single surface-accessible histidine.