• Journal of Information Technology Applications and Management
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• 제13권4호
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• pp.141-153
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• 2006

According to supply of super high way internet service, importance of security becomes more emphasizing. Therefore, flawless security solution is needed for blocking information outflow when we send or receive data. large enterprise and public organizations can react to this problem, however, small organization with limited work force and capital can't. Therefore they need to elevate their level of information security by improving their information security system without additional money. No hackings can be done without passing invasion blocking system which installed at the very front of network. Therefore, if we manage.isolation log effective, we can recognize hacking trial at the step of pre-detection. In this paper, it supports information security manager to execute isolation log analysis very effectively. It also provides isolation log analysis module which notifies hacking attack by analyzing isolation log.

• Journal of Power Electronics
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• 제16권4호
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• pp.1256-1267
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• 2016

Distributed stray inductance exerts a significant influence on the turn-off voltages of power switching devices. Therefore, the design of low stray inductance bus bars has become an important part of the design of high-power converters. In this study, we first analyze the operational principle and switching transient of a T-type converter. Then, we obtain the commutation circuit, categorize the stray inductance of the circuit, and study the influence of the different types of stray inductance on the turn-off voltages of switching devices. According to the current distribution of the commutation circuit, as well as the conditions for realizing laminated bus bars, we laminate the bus bar of the converter by integrating the practical structure of a capacitor bank and a power module. As a result, the stray inductance of the bus bar is reduced, and the stray inductance in the commutation circuit of the converter is reduced to more than half. Finally, a 10 kVA experimental prototype of a T-type converter is built to verify the effectiveness of the designed laminated bus bar in restraining the turn-off voltage spike of the switching devices in the converter.

• 한국항공우주학회지
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• 제41권1호
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• pp.25-30
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• 2013

집적형 하이브리드 구동장치는 적층형 압전재료(압전스택)를 이용한 마이크로 펌프에서 토출되는 유체로 피스톤을 구동시키는데 크기는 작으면서도 큰 구동력과 높은 속도를 동시에 출력할 수 있는 새로운 개념의 통합 구동장치로서 현재 소형화 및 고출력을 요구하는 항공 우주, 유도무기 등 다양한 분야에서 광범위하게 연구되고 있다. 본 연구에서는 이러한 하이브리드 구동장치의 구동원리 및 성능 시험에 대해 소개하였다. 우선 구동장치의 주 동력인 압전 스택의 성능 시험을 수행함으로써 압전 스택의 구동전력과 구동시간에 따른 성능 변화를 관찰하였고 다음 구동장치의 성능 시험을 통해 구동장치의 최대 이송속도와 최대 구동력을 측정하였다. 구동장치의 최대 이송속도는 53.3 mm/s로, 최대 구동력은 240.7 N으로, 최대 일률은 3.2 W로 측정되었다.

• 한국군사과학기술학회지
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• 제25권4호
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• pp.401-411
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• 2022

As the role of high-value air assets(e.g., AWACS, JSTARS, Rivet Joint, E-2) becomes more critical in modern warfare, the air escort for these assets blocking attacks from any potential enemy fighter also becomes vital. Without the escort, the operations of the assets become restricted. However, such an escort is not always possible due to the limited flight time of the escort fighters. In this paper, we introduce an escort tactics for high-value air assets performed by the manned-unmanned teaming composed of a transport aircraft and UAVs(unmanned aerial vehicles). In this tactics, the transport aircraft plays the role of an aircraft carrier, which carries, launches, and retrieves the UAVs. The missions of UAVs in this tactics are to detect and engage enemy fighters. We also introduce the simulation result of this tactics to identify the UAVs' required capabilities and optimal maneuvering.

• 한국재료학회지
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• 제26권8호
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• pp.417-421
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• 2016

We improve the energy conversion efficiency (ECE) of a dye sensitized solar cell (DSSC) by preparing a working electrode (WE) with localized surface plasmon resonance (LSPR) by inducing Au thin films with thickness of 0.0 to 5.0 nm, deposited via sputtering. Field emission scanning electron microscopy and atomic force microscopy were used to characterize the microstructure of the blocking layer (BL) of the Au thin films. Micro-Raman measurement was employed to confirm the LSPR effect, and a solar simulator and potentiostat were used to evaluate the photovoltaic properties, including the impedance and the I-V of the DSSC of the Au thin films. The results of the microstructural analysis confirmed that nano-sized Au agglomerates were present at certain thicknesses. The photovoltaic results show that the ECE reached a value of 5.34% with a 1-nm thick-Au thin film compared to the value of 5.15 % without the Au thin film. This improvement was a result of the increase in the LSPR of the $TiO_2$ layer that resulted from the Au thin film coating. Our results imply that the ECE of a DSSC may be improved by coating with a proper thickness of Au thin film on the BL.

• 한국수산과학회지
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• 제30권6호
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• pp.1033-1043
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• 1997

In order to understand the generation mechanism of the Ulleung Eddy, we carried out a series of numerical experiments using the nonlinear 11/2 - layer model allowing the inflow of the Tsushima Current. According to our numerical results, the Ulleung Eddy was generated due to the inflow variations of the Tsushima Current. Its inflow through the Korea Strait was deflected to the east due to the Coriolis force and the nonlinear self advection. Thus, an anticyclonic motion was formed at the north of the Korea Strait. The inflow became a coastal boundary current, and finally flowed out model ocean through the eastern exit. When the speed of inflow decreased slowly, the eddy- like motion at the north of the Korea Strait changed into an enclosed anticyclonic eddy of about 200 km in diameter. The Ulleung Eddy became circular shape due to the nonlinear self advection, then changed into elliptical shape in meridional direction because of the blocking effect of the western boundary.

• 대한약리학회지
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• 제16권1호
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• pp.35-39
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• 1980

In this study, the effects of phenoxybenzamine and related drugs on the action of CCK-PZ and caerulein were examined in isolated gall bladder of guinea pig and higher esophagus strip of fowl. The strips were placed in a bath containing Locke-Ringer solution maintained at $38^{\circ}C$. Oxygen was continuously bubbled through the solution. The contractile response was measured isometrically by a force displacement transducer connected to polygraph. In isolated gall bladder preparation caerulein produced contractile response of CCK-PZ type, but the relative potency on a weight basis was 30 times stronger than CCK-PZ. The response of caerulein or CCK-PZ was not blocked by cholinergic blocking agent and both alpha and beta adrenergic blockades, however, the response of caerulein or CCK-PZ was exceptionally blocked by phenoxybenzamine. In isolated esophagus strip CCK-PZ with high concentration produced marked contraction which was not modified by atropine and other blocking agents, whereas the response was blocked by phenoxybenzamine. These results lead to the conclusion that phenoxybenzamine inherently inhibits the contractile response of CCK-PZ and caerulein on esophagus and other smooth muscle.

• 한국해안·해양공학회논문집
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• 제22권1호
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• pp.10-17
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• 2010

투과성 이중 반원통 구조물과 경사 입사파간의 상호작용문제를 선형포텐셜 이론을 사용하여 살펴보았다. 투과성 이중 반원통 구조물은 바닥에 고정된 동심원상으로 배열된 2개의 원통 구조물로 이루어지며 각 원통 구조물의 전면은 일정한 공극율을 갖는 투과벽으로 후면은 투명한 벽으로 구성된다. 전면 투과벽의 공극율과 간격 그리고 파랑특성(주파수, 입사각)을 변화시키면서 파랑하중과 처올림 파형 그리고 파 차단성능을 살펴보았다. 파 차단 성능의 척도로서 차단영역내의 평균제곱 변위의 제곱근(R.M.S.)을 사용하였다. 투과성 반원통 구조물은 불투과성 구조물과 비교하여 차단영역내의 파도응답을 감소시키며 구조물에 작용하는 파랑하중을 크게 줄여준다. 특히 이중 구조물은 고주파주 영역에서 단일 구조물보다 파를 차단하는데 효과적이다.

• 한국산학기술학회논문지
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• 제17권12호
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• pp.482-487
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• 2016

파장 400 nm 이하의 자외선은 눈 건강에 매우 해롭다. 특히 UVA (315 nm ~ 400 nm)는 백내장, 설안염, 초자체경화 등을 유발할 수 있고, UVB (280 nm ~ 315 nm)는 결막염, 각막염 및 설안염 등을 일으킬 수 있다. 따라서 폴리머 안경렌즈를 사용함에 있어서 자외선의 차단 기능과 가시광선 영역에서 투과되는 빛을 증가시키고, 안경렌즈 표면에서 형성되는 허상을 방지하는 반사방지 기능은 매우 중요하다. 본 연구에서는 m-자일릴렌 디이소시아네이트 모노머와 2,3-Bis-1-propanethiol 모노머 및 벤조트리아졸 UV 흡수제 (SEESORB 709), 안료 혼합물, 이염화 이부틸 주석 촉매제, 알킬인산 에스터 이형제 등의 혼합물을 인젝션 몰드 방법으로 열중합 공정을 적용하여, 굴절률 1.67의 고굴절률 폴리머 안경렌즈를 제조하였다. 폴리머 안경렌즈 표면에서의 반사를 줄이기 위하여 렌즈 양면에 다층박막 반사방지 코팅을 E-beam 증착 시스템으로 코팅하였다. 자외선 차단 폴리머 안경렌즈의 광학적 특성을 UV-visible spectrometer로 분석하였고, 반사방지층을 구성하는 박막의 굴절률, 표면거칠기 등과 같은 박막소재 특성을 각각 Ellipsometry 및 원자힘 현미경으로 분석하였다. 분석 결과 제조된 안경렌즈는 395 nm 파장 이하의 자외선을 99% 이상 완벽하게 차단하였다.

• 한국의류산업학회지
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• 제14권2호
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• pp.294-303
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• 2012

This study was designed to develop air force mechanic parka, evaluate it, and ultimately provide functionally superior parka to the air force. The development process was 1) conducting a survey, 2) identifying problems and shortcomings of currently-supplied parkas, and 3) improving the design, pattern and materials. The newly-developed parkas were evaluated in terms of their ease of fit, clothing mobility, and insulation. Ease of fit was evaluated by subjects' sensory tests, and clothing mobility was by fitness-for-motion tests and range-of-motion tests using a Goniometer. Evaluation on insulation was conducted by thermal manikins. Findings of this study were as follows: 1. In the subjective evaluation on clothing mobility, new parkas were considered to have sufficient ease of fit while previous ones scored much lower, confirming the improvement of the new version. 2. Both subjective tests and ROM measurements on fitness for motion verified the superiority of the new parkas. 3. Insulation tests found that although insulation capability of newly-developed parkas was at a similar level to those of the previous ones, their insulation capability per unit weight was superior, demonstrating that new parkas were better at blocking heat conduction. When making changes in parka patterns and designs to enhance the mobility, it was necessary to maintain the insulation function. The new parkas developed by this study was verified to be superior to the previous ones in their insulation and clothing mobility.