• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.188-194
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• 1999

Fiber reinforced composite materials are widely used in automotive industry to produce parts that are large, thin. lightweight. strong and stiff. It is very important to know a charge shape in order to have good products in the compression molding. In particular, the product such as a bumper beam is composed of the random and unidirectional fiber mats. This study analyzes numerically the characteristics of flow fronts such as a bulging phenomenon made by changing viscosity of random mat and unidirectional fiber mat and slip parameters. And it is discussed that the effect of ratio of viscosity A and stack type on mold filling parameters

• 천문학논총
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• 제19권1호
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• pp.71-76
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• 2004

We have developed a tool for measuring optical aberrations of telescope. We adopt curvature sensing technique and use the least square method for finding the amplitudes of the Zernike polynomials. This tool runs under the PC Linux system and the PC windows system with Linux emulators such as Cygwin. The program for UNIX system is used for optical alignment of 1.8M optical telescope at the Bohyunsan Optical Astronomical Observatory (BOAO) and the PC based program is used for the Korea Astronomy Observatory (KAO) wide field telescope (named NEOPAT-3). Our tool is found to be efficient for precise measurement of the optical aberrations of telescopes.

• East Asian Economic Review
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• 제16권1호
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• pp.3-23
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• 2012

The recent global financial crisis has highlighted the importance of international monetary and financial system reform. The current system is deemed to be no longer adequate to meet the needs of a complex, integrated world economy. With regards to the reform of the international monetary system, there have been various proposals both in demand and supply sides. These include proposals to build a stronger global financial safety net, to diversify the supply of international reserve currency and so on. These proposals face trade-offs between desirability and political feasibility. Given this situation, a practical transition would be to strengthen policy coordination among the major economies and to reform the International Monetary Fund. The success on both fronts depends heavily on global economic governance reform and the role of the G20. Increased status and representation of Asian countries in the G20 give both privileges and responsibilities to Asians. To meet these responsibilities, Asians should put forth greater efforts to develop their intellectual leadership in global economic issues through creating new forum and institutions.

• 대한기계학회논문집A
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• 제20권9호
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• pp.2843-2853
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• 1996

The multi-point procedure is developed to predict the shape change of a semi-elliptical surface crack during stable fatigue crack growth. 3-D stress intensity factors along a crack front are calculated using the simplified 3-D J-intergral. Crack growth rate coefficient in the Paris law is assumed to be constant along the crack growth. Crack growth rate is set to be the distance between the two parallel tangent lines on the two semi-elliptic crack fronts before and after crack growth.

• 한국대기환경학회지
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• 제11권1호
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• pp.85-93
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• 1995

Measurements of ground level ozone concentrations were made in a rural area of Chongwon (Choongbook Province) from June 1993 to July 1994. High values frequently exceeding 100 ppb (ambient air qualyty standard of Korea) were recorded. High ozone concentrations in the boundary layer were primarily correlated with the several meteorological parameters in warm seasons: pressure, radiation, temperature, precipitation and wind velocity. The annual average concentration of ozone at Chongwon was 17ppb, and this value was relatively higher than those for other cities in Korea. O$\_$3/ concentrations were observed to increase when the ridge of a surface anticyclone was passing over the region, and maximum values(.geq.100 ppb) were observed on the rear sides of high pressure centers and in the warm sectors of cyclones(well head of cold fronts). The ozone concentrations had a negative correlation with the concentration of primary pollutants(e.g., total hydrocarbons).

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.128-134
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• 2006

A characterization of turbulent reacting flows has proved difficult owing to the complex interaction between turbulence, mixing, and combustion chemistry. There are many types of time scales in turbulent flame which can determine flame structure. This counter jet type premixed burner produces high intensity turbulence. The goal is to gain better insights into the flame structures at high turbulence. 6 propane/air flames gave been studied with high velocity fluctuation in bundle type nozzle and in one hole type nozzle. By measuring velocity fluctuation, turbulent intensity and integral length scale are obtained. And sets of OH LIF images were processed to see flame structure of the mean flame curvatures and flame lengths for comparison with turbulence intensity and turbulent length scales. The results show that the decrease in nozzle size generates smaller flow eddy and mean curvatures of the flame fronts, and a decrease in Damkohler number estimated from flow time scale measurement.

• 한국생산제조학회지
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• 제21권3호
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• pp.473-478
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• 2012

In this paper, the air bubble formation mechanism in the rectangular and triangular line-and-space pattern during dispensing UV Nanoimprint Lithography (UV-NIL) at an atmospheric condition is studied. To investigate the air bubble formation, an analytic model based on geometric approach and a numerical model based on CFD(computational fluid dynamics) were used in the analysis. It was found in the numerical analysis that every time the flow front passed through a corner of the pattern, it proceeded with a newly formed shape, occurring due to interface reconfiguration, since the flow fronts were formed such that they minimized the surface energy. Moreover, the conditions for the air bubble formation were investigated by applying the analytic analysis based on geometric approach and the numerical analysis. Good overall agreement was found between the analytic and numerical analysis.

• 기술혁신연구
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• 제10권1호
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• pp.174-200
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• 2002

Technological capabilities of POSCO (Pohang Iron & Steel Co.) have been developed through acquisition, catch-up, and generation stage. In 1970s standardized operation technologies were acquired based on Japan's technological cooperation. The prime route of technological acquisition was overseas training and operation technologies were articulated by mock and real operation. In 1980s POSCO focused to catch-up advanced technologies through in-house R&D activities. Technological informations were broadly accumulated, task force teams were constructed for important technological tasks, and the scope of technological innovation covered nearly all fields. In 1990s POSCO launched long-term projects based on the large-scale investment and challenged the new fronts of steel technologies. Frontier technologies such as smelting reduction and thin slab casting were early commercialized and new technological concepts were emerged. In conclusion, this article suggests some implications on the development of technological capabilities in Korea.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.181-182
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• 2000

Due to the instability of the EKWC, the oceanic conditions in the East Sea are affected by the fluctuations of the moving paths of the TWC, polar fronts, and warm eddies. In particular, warm eddies play an important role in spreading the surface water of the East Sea from its southern coastal region to its interior region (Isoda, 1994). However, the fluctuation characteristics of the meandering TWC and the warm eddies in the East Sea are not yet known due to the instability of the TWC. Hideaki(1999) showed that the moving paths and features of the TWC in the coastal regions of Japan were not constant. (omitted)

• 한국문헌정보학회지
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• 제31권1호
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• pp.125-151
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• 1997

이 연구는 현 단계 한국문헌정보학이 각종 사회환경의 변화에 유연하게 대응할 수 있는 발전전략을 모색하는 것이다. 이를 위해 다음의 두 가지 실천전략을 제시하였다. 첫 번째는 주체적인 학술연구의 전략으로서, 연구자들이 기존의 학술논문쓰기 방법을 과감하게 탈피하여 도서관과 관련기관의 일상생활을 있는 그대로 기술하고 설명할 수 있는 자유롭고 쉬운 양식의 글 쓰기 전략을 제시하였다. 또한 한국의 낙후된 도서관현장의 발전에 참조가 되는 방향에서 외국의 원전을 읽고 번역하는 전략도 함께 제시하였다. 두 번째는 학술운동의 전략으로서, 연구자와 현장사서들이 함께 참여하여 우리의 학문적 내실을 다져내며 한국문헌정보학이 한국사회과학의 당당한 일원으로서 참여할 수 있는 전략을 제시하였다.