• Animal Systematics, Evolution and Diversity
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• 제33권3호
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• pp.145-161
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• 2017

We reviewed eight South Korean species of the genera Scambus Hartig, 1838 and Tromatobia $F{\ddot{o}}rster$, 1869. Among them, the Genus Scambus Hartig, 1838 is a moderately large group that includes 152 species worldwide. The South Korean genus Scambus Hartig, 1838 only includes one species, Scambus calobatus (Gravenhorst, 1829). The Tromatobia $F{\ddot{o}}rster$, 1869 group is a relatively small genus, including 33 worldwide species. This group is recorded for the first time from South Korea. Also, we report seven newly recorded species: Scambus nigricans (Thomson, 1877), Scambus vesicarius (Ratzeburg, 1844), Tromatobia flavistellata Uchida and Momoi, 1957, Tromatobia nipponica Uchida, 1928, Tromatobia ornata (Gravenhorst, 1829), Tromatobia ovivora (Boheman, 1821), and Tromatobia variabilis (Holmgren, 1856). A key to South Korean species of the genera Scambus Hartig, 1838 and Tromatobia $F{\ddot{o}}rster$, 1869, diagnoses and illustrations are provided.

• 한국자동차공학회논문집
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• 제6권5호
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• pp.10-19
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• 1998

The erosion of electrode in spot welding of aluminium alloy by direct current is dependent on the electric polarity. The positive electrode is much more eroded than the negative one. To explain this phenomenon, Peltier effect has been generally accepted as a unique theory. In this study Peltier effect was evaluated by calculations on the basis of some references and experiments. The difference of heat generated by Peltier effect on both electrode surfaces was, however, only 4% of total heat generated during wel- ding. Because of insufficient explanation, Kohler theory, which is mainly affected by thin oxide film, was introduced. A theoretical calculation showed 17% of the temperature difference between the positive and negative electrode, in case "surface voltage" resulted from oxide film was 30% of total contact voltage. This revealed that the erosion of electrode could be more affected by Kohler theory than effect.an effect.

• Animal Systematics, Evolution and Diversity
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• 제30권2호
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• pp.95-102
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• 2014

The four species of the suborder Holaxonia, Anthogorgia japonica Studer, 1889 of family Acanthogorgiidae, Astrogorgia rubra (Thomson & Henderson, 1906), Euplexaura attenuata (Nutting, 1910), and E. erecta (Kukenthal, 1908) of family Plexauridae have been newly recorded in Korea. They were collected from intertidal and sublittoral zones in the western and southern coasts and Jeju-do Island of Korea by SCUBA diving and fishing nets from 1969 to 2010. This study approaches holaxonians by focusing on external and internal morphologies including size, form, and color of colonies, branches, polyps, coenenchyme, axis, and spicules. Anthogorgia japonica is characterized by its planar growth form, dichotomously branched form, non-retractile polyps, and Astrogorgia rubra by arrangement of calyxes being situated in lateral side at stems and alternately in all sides at branches. Euplexaura attenuata is sparsely and laterally branched colony, and has straight wand-like stems. Euplexaura erecta has branches which run parallel to the main stem.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 추계학술발표대회 개요집
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• pp.130-132
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• 2004

석출물의 용해 온도보다 낮은 온도에서의 석출물의 야금학적인 거동을 예측하였다. 평균 사이즈 석출물의 지속적인 성장만을 고려하는 기존의 모델과 달리, 본 연구에서 제안된 모델의 경우에는, Gibbs-Thomson equation으로부터 유도되는 critical particle size를 고려하였다. 제안된 모델을 이용해서 TiN석출물의 거동을 예측하였으며, 이를 실험 결과 및 기존의 모델에 의한 예측 값과 비교하였다. 석출물들의 분포는 전형적인 log-normal 분포를 따르는 것으로 관찰되었으며, 본 연구에서 제안된 모델이 기존의 모델에 비해서 실험결과와 잘 일치함을 확인할 수 있었다.

• 설비공학논문집
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• 제6권1호
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• pp.11-19
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• 1994

An optimal design for Gifford-McMahon/Joule-Thomson(GM-JT) refrigerators was performed by a numerical method. The design goal was to meet the cooling requirement for MRI systems, which was 3 Watt at 4 K. A general cycle analysis program was written to calculate the cooling capacity of the GM-JT refrigerators for the givenstage GM refrigerator. The program was executed for a specific refrigerator with various design parameters. The optimal values for the maximum cooling were found for the sizes of the heat exchangers, the mass flow rate of helium, and the compression pressure.

• 산업기술연구
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• 제24권A호
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• pp.91-97
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• 2004

This paper describes the design of a 2-phase stepping motor driver using CPLD(Complex Programmable Logic Device). The driver IC such as L297(SGS-Thomson Microelectronics), which is mostly used has some difficulties in PWM control because of the switching noise of power MOSFETs. It causes current ripple and acoustic noise. To improve theses characteristics, we proposed a new current control method that the output PWM frequency is almost constant using a digital filter. Also we proposed constant current method for 1-2 phase(half step) excitation. The proposed method is implemented with CPLD(Xilinx, XC9572-PC44). Experimental results show the effectiveness of the proposed method.

• 한국응용곤충학회지
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• 제56권3호
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• pp.283-287
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• 2017

한국산 자루맵시벌속(Genus Netelia Gray)의 12개 아속 중 하나 인, 애자루맵시벌아속의 분류학적 연구를 수행하였으며, 그 결과로 1미기록종[Netelia (Parabates) nigricarpus (Thomson, 1888) (검은점애자루맵시벌: 신칭)]을 국내에 처음 보고한다. 애자루맵시벌아속의 3종에 대한 식별 형질과 외형 사진을 제공한다.

• 대한기계학회논문집B
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• 제28권1호
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• pp.89-98
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• 2004

In this paper, we develope a dispersion model based on the Generalized Langevin Model. Thomson's well-mixed condition is the well known criterion to determine particle dispersion. But, it has 'non-uniqueness problem'. To resolve this, we adopt a turbulent model which is a new approach in this field of study. Our model was greatly simplified under the self-similarity condition, leaving model only two model constants $C_{0}$ and ${\gamma}$$_{5}$ that control the dispersion and spin which measures rotational property of the Lagrangian particle trajectory. We investigated the sign of spin as well as magnitude by using the Direct Numerical Simulation. Model calculations were performed on the neutrally stable boundary layer flow. We found that spin has weak effect on the particle dispersion but it shows the significant effect on the horizontal flux compared to the zero-spin model.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1995년도 춘계학술대회논문집; 전남대학교, 19 May 1995
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• pp.322-327
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• 1995

무기체계 개발에서 개발장비의 내구성은 개발자가 고려해야될 가장 중요한 항목 중에 하나이다. 그러나 이런 개념이 꼭 무기체계 개발에만 국한된다고 생각되지는 않는다. 실제로 여러 선진국에서는 자동차나 항공기 그리고 인공위성에 탑재되는 거의 모든 장비를 환경시험을 통하여 엄격하게 관리하고 있는 것이 사실이고, 우리 기업들 역시 진동을 비롯하여 온도, 충격, EMI/EMC등 환경시험분야에 많은 관심을 기울이고 있기 때문에 이런 환경시험수준 결정절차나 과정 그리고 결과를 나름대로 파악하는 일은 매우 중요하다고 판단된다. 여러 환경시험 중에서도 진동시험은 가장 보편적이고 오래된 것으로 진동시험을 합리적으로 수행하기 위해서는 무엇보다도 합리적이고 타당한 진동시험수준 결정이 필요하다. 미 군사규격도 Sinusoidal이나 Swept Sine에서 Random Vibration 시험까지 여러 종류의 시험에서 각각에 맞는 시험 방법을 제시하고 있으나 이를 뒷받침하는 이론적 설명은 부족한 편이다. 이런 상황에서 프랑스가 환경시험, 특히 진동 시험에 많은 연구를 하고 있어서 이번에 국방과학연구소가 프랑스의 Thomson-CSF사와 함께 일하면서 배우고 나름대로 연구한 것을 앞장에 언급하였다. 세부적인 내용이 많이 포함되지는 못했지만 가능하면 여러 분야에서 이런 작업이나 연구에 관하여 많은 관심을 가져 주기를 바란다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1999년도 학술대회논문집-국제 전기방전 및 플라즈마 심포지엄 Proceedings of 1999 KIIEE Annual Conference-International Symposium of Electrical Discharge and Plasma
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• pp.58-63
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• 1999

In order to analyze the discharge-pumped KrF excimer laser, computer simulation code is developed. On the other hand, the electron velocity distribution in a discharge plasma, measured by the Thomson scattering method, showed the Maxwellian, while the code predicted non-Maxwellian. This disagreement was solved by introducing the electron-electron collision into the simulation code. We also developed a simulation code on the CO2 laser-heated plasma in high-pressure Ar gas, and estimated the formation process of Ar2 excimer. The code predicted the possibility of the Ar2 laser action at 126 nm.