• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1999년도 추계 학술대회논문집
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• pp.71-76
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• 1999

The base flow regions of a three-body sounding rocket containing multiple exhaust plumes were numerically investigated in three dimensions for a free stream Mach number of 2.7 at flight altitude 18.5 km. The flowfields were calculated using the full compressible Navier-Stokes equations with an one-equation turbulence model of Baldwin-Earth. The present calculations were executed based upon a chemically frozen, single perfect gas model assumption. Due to the symmetry of the three-body rocket of each single nozzle, only one fourth of the computational domain was considered for the analysis. The results indicate that a babe heating effect is not considerable due to the small expansion of the plumes. In the base, however, a low speed recirculating flow dominates the region.

• 대한기계학회논문집A
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• 제30권2호
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• pp.171-178
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• 2006

Experimental and theoretical study of the non-planar response motions of a circular cantilever beam subject to base harmonic excitation has been presented in this paper work. Theoretical research is conducted using two non-linear coupled integral-differential equations of motion. These equations contain cubic linearities due do curvature term and inertial term. A combination of the Galerkin procedure and the method of multiple scales are used to construct a first-order uniform expansion for the case of one-to-one resonance. The results show that the non-linear geometric terms are very important for the low-frequency modes of the first and second mode. The non-linear inertia terms are also important for the high-frequency modes. We present the quantitative and qualitative results for non-planar motions of the dynamic behavior.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 춘계학술대회 논문집
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• pp.269-274
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• 1999

Aluminum alloy has not only physical characteristic of very high activated high thermal conductivity and high thermal coefficient expansion but also special characteristic of great difference fusibility of hydrogen between liquid and solid phase. Because of these reasons, Aluminum welding is very different. Therefore, only MIG welding method should be applied instead of other welding methods. In this study, in order to select optimal welding conditions, it has been to investigate the effectiveness on the welding current, welding speed, flow rate of gas and welding voltage to occurrence of spatters, external shape of bead, state of penetration and width and hight of bead by using filer metal of A15356(dia. 1.21mm) on the base material of A16061.

• 사상체질의학회지
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• 제12권2호
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• pp.43-55
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• 2000

Purpose This study is intended to catch the expansion of theory of Sasang Constitutional Medicine through comparison prescription of Sasang-Yihak-Chobonguen with prescription of Dongyi-Soose-Bowon Method I studied the archive of prescription and medicines concerned in the Sasang-Yihak- Chobonguen with Dongyi-Soose-Bowon Result and conclusion 1. The base of theory on prescription of Sasang-Yihak-Chobonguen is based on Naesang -oigam theory but the base of theory on prescription of Dongyi-Soose-Bowon is based on Pyoribyung theory of Sasang constitutional Medicine. 2. Medicines are confused in prescription of Sasang-Yihak-Chobonguen but medicines are not confused in prescription.

• 분석과 대안
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• 제2권2호
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• pp.143-162
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• 2018

This paper focuses on the policy framework about "Quantitative and Qualitative Easing (QQE)" of Japan, and analyzes reasons why the policy goal was not reached. The QQE was introduced by the Bank of Japan in 2013 with the purpose of meeting the price stability target of 2% and getting out of deflation that prevents sustained price decline. However, despite the implementation of the bold monetary easing policy unprecedented in the world, the policy goal was not achieved as of June 2018. As a result of analyzing the causes, the following three structural factors were confirmed. 1) The rise in prices by QQE was limited because Japan's consumer price is strongly depending on import price. 2) The effect is high degree of uncertainty and limited because theoretical framework of reflationist which adopted QQE depends on "expectation formation" by "self-fulfilling expectation" and "multiple equilibria". 3) It was confirmed that the expansion of the monetary base did not lead to money stock due to the existence of Japanese liquidity trap, long-term low interest rate policy.

• Spatial Information Research
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• 제18권1호
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• pp.39-48
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• 2010

최근 세계 여러 나라들은 해양개발이 활성화됨에 따라 자국의 해양영토 확보에 총력을 기울이고 있으며, 인접국가간 분쟁이 잦아지면서 해양영토의 중요성은 급격히 부각되고 있다 특히 삼면이 바다로 이루어진 우리나라의 경우 주변국들과 분쟁의 소지를 많이 내포함에 따라 우리나라의 해양영토 확보를 위한 노력이 매우 필요하다. 따라서 본 연구에서는 국가의 해양영토의 국가관할권을 결정하는 영해기준점의 실태 조사 및 분석을 통하여 영해기준점의 재질, 매설 지역 선정 및 측량절차 간소화, 조위관측 및 멀티빔 음향측심기를 이용한 정확한 위치 선정 등의 정비방안을 제시했으며, 국가 기준점으로서 영해기준점의 등급향상 방안을 제시함으로써 2등 국가기준점으로 자리매김할 수 있는 근거를 마련하였다. 또한 타 국가기준점과의 상호 연계 및 영해기준점 관리의 효율성 및 효용성을 극대화하기 위하여 영해기준점과 영해보조기준점 DB 표준방안을 제시하였다. 마지막으로 현 영해기준점관련 작업규정의 검토를 통하여 조사 및 유지관리에 관한 개선된 작업규정과 영해기준점의 홍보 및 대외협력 방안을 제시함으로써 향후 주변국가와의 영토분쟁 시 우위를 선점할 수 있는 해양영토의 기준 및 해양영토 확장을 위한 기반을 마련하고자 하였다.

• 한국레이저가공학회지
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• 제4권3호
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• pp.40-44
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• 2001

Microbump formation during CO$_2$ laser texturing of glass substrates is examined in this paper. Experimental results show that different bump shapes (dome-shaped, with a central dimple, and with a peripheral rim) are generated depending on the laser fluence. A theoretical model for the process is suggested based on thermoelastic behavior but limited only to the dome-shaped bump. The dimensions (maximum height and base area) of the bump shows a logarithmic dependence on laser fluence as expected from the theory. Numerical computation reveals that the effect of thermal diffusion is not negligible for relatively long laser pulses.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1371-1374
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• 1995

It is well known that the degradation of transformer oil conseqently lead to the failure of transformer. This paper discussed the characteristics of the degradation sensor checking transformer oil condition in live line. The degadation sensor is composed of base ring, electrodes and porous ceramic, passed through the transformer oil and checks the transformer oil condition through sensor's leakage current. So it is important to minimize the leakage current of base ring and connection parts. To investigate the leakage current of base ring and connection parts the characteristics of V-T-I and DC 2 KV and other examinations were performed. It is verified that ionized transformer oil caused by the expansion of temperature increases in the leakage current of porous ceramic sensor. It is certification that the leakage current of other parts of porous ceramic is very small(about 2%) compared with the porous ceramic body and it is confirmed that the leakage current in porous ceramic is changed sensitively according to the new oil(NO) and and the degradation oil(DO).

• 한국공작기계학회논문집
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• 제15권5호
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• pp.7-13
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• 2006

This study was to evaluate the effect of carbon content on metallic change and fatigue characteristics with Fe-29%Ni-17%Co, low heat expansion alloy, widely using electronic components, precision machines, and sealing with glass and metal etc. The steels were fabricated with variation of carbon content, 0, 0.03, 0.06, 0.1, and 0.20% with VIM and tensile test and fatigue test were performed to achieve the above purpose. The more carbon content, the higher hardness value and yield strength. But elongation of 0.03%C, 0.06%C, and 0.10%C specimen decreased about 2.2%, 1.5% and 0.8% respectively more than that of the base metal. Especially the strength and elongation of 0.20%C specimen increased simultaneously about 14.4% and 7.5%. Fatigue life of 0.03%C specimen decreased but the more carbon content, the higher fatigue life over 0.06% carbon content more than that of base metal.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1765-1768
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• 1996

It is well known that the degradation transformer oil is mainly effected to the failure of transformer. In this paper it is discussed the characteristics of the degradation sensor checking transformer oil condition in live line. The degadation sensor composed with base ring, electrodes and porous ceramic passed through the transformer oil and checked the transformer oil condition with sensor's leakage current. It is important to minimize the leakage current of base ring and connection parts. To investigate the leakage current of base ring and connection parts it is examined the characteristics of V-T-I and DC 2 KV and other examinations. It is verified that ionized transformer caused by the expansion of oil temperature increase in the leakage current of porous ceramic sensor. It is certificated that the leakage current of other parts of porous ceramic is very small (about 2 %) than the porous ceramic and it is confirmed that the leakage current in porous ceramic is changed sensitively according to the new oil(NO) and and the degradation oil(DO).