• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.127-130
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• 1988

This paper describes digital simulation of harmonic elimination in the FC-TCR. (Fixed Capacitor and Thyristor Controlled Reactor) A model at harmonic frequency is developed for a STATIC VAR compansator. The model is shown to be useful in predicting resonance condition. A new variable filter is used for synthesized harmonic elimination.

• 한국안전학회지
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• 제10권2호
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• pp.72-76
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• 1995

An electrostatic passive neutralizer without HV power source has been used widely to reduce charges on insulators such as running plastic films, papers and cloths, but its elimination characteristics and safely have been hardly investigated in detail. Especially, an operation of the passive neutralizer depends primarily on the charged insulator and the elimination ability does not depend on only the neutralizer, because an electrostatic elimination is caused by corona discharges occurring between the passive neutralizer and charged insulator. From a reason described above, the purpose of this study is to examine experimentally the elimination ability of the passive neutralizer. Experiments were made on the corona discharges between the passive neutralizer and charged insulator running at high velocity in practical field to make clear the setting condition of the passive neutralizer for operating effectively and safely. Results obtained from field experiments are presented in this paper.

• 한국세라믹학회지
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• 제27권2호
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• pp.169-178
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• 1990

The sintering characteristics of ZrO2 were analyzed in terms of pore microstructure and kinetics of pore elimination. The pore structue of the ZrO2 sample prepared from colloid suspension was characterized by three distinct types of pores ; intradomain, interdomain, and intergglomerate pores. Sintering data at 1600$^{\circ}C$ showed that pores larger than a certain critical size(∼3$\mu\textrm{m}$) were difficult to remove, and this was analyzed in terms of the interagglomerate pore formed from the suspension under the condition of low kinetic stability, that is, the stability ratio smaller than its critical value. A theoretical equation for densification rate was derived and was applied to the densification rate of the ZrO2 polycrystalline body containging both the matrix(the 1st-generation) pores and the interagglomerate (the 2nd-generation) pores under the condition of slow grain growth.

• 대한전자공학회논문지
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• 제23권3호
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• pp.409-414
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• 1986

To eliminate the requirement of multiplications in nonrecursive filter realization, the use of a delta modulation(DM) has been studied by several researchers. However, the structure of DM filters inevitably contains an intergrator that is cascaded with the arithmetic unit to operate convolution summation. In this paper we porpose a method to determine the coefficients that may be used for implementation of a DM filter without an integrator. Also, we obtain the condition by which one can exclude the response errors due to the elimination of the integrator. By computer simulations it is shown that the performance of the proposed filter is very good, providing that the condition is satisfied.

• Bulletin of the Korean Chemical Society
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• 제25권9호
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• pp.1379-1384
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• 2004

Rearrangements of 1,3-oxathiolane sulfoxides 8 and 9 in the presence of base are described from a mechanistic viewpoint of sigmatropic and elimination reactions. In the presence of triethylamine the (Z)-sulfoxide 8 gave the corresponding thiolsulfinate 10 by way of dimerization of the sulfenic acid intermediate 2 at room temperature while the (E)-sulfoxide 9 was recovered even after refluxing in ethyl acetate by the reversal of the [2,3]-sigmatropic rearrangement of the sulfenic acid 4. Triethylamine promoted the developing charge separation in the transition state of the sigmatropic rearrangement of the (Z)-sulfoxide 8 to facilitate the ring opening to the sulfenic acid 2. The reason for more facile ring opening of the (Z)-sulfoxide 8 in comparison with the corresponding (E)-sulfoxide 9 is attributable to the differences in the reactivity of the hydrogen adjacent to the carbonyl group. Triethylamine was not strong base to deprotonate the carbonyl-activated methylene hydrogen of the (E)-sulfoxide 9 but enough to catalyze the sigmatropic process of the sulfoxides. The sulfenic acid 2 dimerized to the thiolsulfinate 10 while the sulfenic acid 4 proceeded the sigmatropic ring closure. In the presence of strong base such as potassium hydroxide, the elimination reaction was predominant over the sigmatropic rearrangement. In this reaction condition, both sulfoxides 8a and 9a gave a mixture of the disulfide 12, the isomeric disulfide 14, and the sulfinic acid 13. Under the strong alkaline condition an elimination of activated hydrogen from the carbon adjacent to the carbonyl group to furnish the sulfenic acid 2a and the isomeric sulfenic acid 18. The formation of the transient intermediate in the reaction was proven by isolation of the isomeric disulfide 14. The reactive entity was regarded as the sulfenic acid rather than sulfenate anion under these reaction conditions.

• 한국물환경학회지
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• 제18권2호
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• pp.159-168
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• 2002

A lab-scale Reverse Osmosis(RO) membrane reactor was installed to investigate the membrane permeability, characteristics of membrane fouling at each conditions, and performance of elimination at different trans-membrane pressure(TMP) in the liquid fertilizer accumulated system. Experimental setup was divided to three different TMP conditions. As a result of experiment, permeability of RO membrane was proportional to the increase of TMP and temperature. After experiment was completed, two types chemical cleaning(remove the organic foulant and inorganic foulant) was done, and recover rate of permeability was each 99.8, 99.7 and 99.7%, respectively. From this experimental data, membrane fouling could be determined that the most of it was recoverable in this system, and major reason of fouling was concentration polarization. Elimination rate of solute substance in the liquid fertilizer indicated very stable(above 99%), except ammonia nitrogen, and the most stable elimination rate was investigated at the highest TMP condition (Run 3).

• 한국가스학회지
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• 제8권4호
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• pp.62-69
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• 2004

정전기 방전으로 인한 재해방지, 생산효율의 향상, 정전기 방전에 민감한 전자소자의 보호를 위하여 각종 생산 공정에서는 정전기의 제전이 필요하다. 그래서 필름생산공장, 도장공장, 반도체 공장 등에서 이러한 정전기를 제거하기 위하여 제전기를 사용하고 있다. 본 연구에서는 전압인가식 제전기 bar의 길이, 동관의 길이 및 전극 간격을 변화시켜가면서 최적의 제전효율을 가지는 조건을 고찰하고, 이러한 조건에서 발생되는 방전에 의한 가연성 가스의 폭발 유무를 연구하였다. 그 결과 제전효율은 각각의 제전 bar에서 접지전극과 침상전극 사이의 간격이 8-11(mm)사이 일 때 최적의 제전효율을 나타내는 것을 알 수 있으며, 최적의 제전효율을 나타내는 bar에 대하여 가연성 가스의 폭발실험을 한 결과 폭발은 일어나지 않는 것을 알 수 있었다. 이상과 같이 본 연구를 통하여 나타난 결과를 이용하여 최적의 제전효율과 안전성을 가지는 방폭형 전압인가식 제전기 개발에 필요한 자료를 제시함으로써 산업현장에서 발생하는 가연성 가스에 의한 폭발사고를 미연에 방지할 수 있을 것으로 사료된다.

• 대한전자공학회논문지SP
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• 제43권1호
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• pp.1-8
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• 2006

본 논문은 다중 참조영상(multiple reference image)에 적용 가능한 새로운 고속 전역탐색 움직임 추정 기법을 제안한다. 제안된 방법은 기존의 비트율을 고려한 연속제거알고리즘(rate constrained successive elimination algorithm: RSEA)을 다중 참조영상에 확대 적용하는 방법이다. 첫 번째 참조영상에 대한 움직임 추정의 계산량에 비해 그 이후 참조영상에 대한 움직임 추정의 계산량이 적어질 수 있음을 보일 것이다. 계산량 감축을 위해, 본 논문에서 최적 움직임 벡터의 후보 블록의 개수를 감소시킬 수 있는 새로운 조건을 소개한다. 실험 결과을 통해 제안된 방법이 기존의 RSEA과 동일한 움직임 추정오차를 가지면서도 계산량을 감소시킴을 보일 것이다.

• 대한한방소아과학회지
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• 제34권3호
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• pp.67-75
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• 2020

Objectives This study is conducted to evaluate Th2 skewed condition control through skin fat barrier formation from the treatment using Coptidis Rhizoma and Glycyrrhiza uralensis extract. Methods The 6-week-old NC/Nga mice were divided into 4 groups: Control group (Ctrl), lipid barrier eliminate treatment group (LBET), Coptidis Rhizoma and Glycyrrhiza uralensis feeding treatment after lipid barrier elimination group (CGFT), dexamethasone feeding treatment after lipid barrier elimination group (DxFT). After 3 days, differences in skin condition, improvement of skin fat barrier, and control of Th2 skewed condition of each group were observed. Results Pathologic skin damage and tissue changes were less in the CGFT group than in the LBET and DxFT groups, and Transepidermal water loss (TEWL) and pH were also significantly decreased (p < 0.05). The filaggrin intensity and positive response also increased significantly in the CGFT group (p < 0.05). Kallikrein-related peptidase (KLK) 7, Protease activated receptor (PAR)-2, Thymic stromal lymphopoietin (TSLP), Interleukin (IL)-4, and the products of the Th2 differentiation process also showed a significant decrease compared to the LBET and DxFT groups (all p < 0.05). Conclusions The Coptidis Rhizoma and Glycyrrhiza uralensis extract causes skin barrier recovery and function recovery through the formation of skin fat barrier. This leads to the conclusion that Coptidis Rhizoma and Glycyrrhiza uralensis extract can control Th2 differentiation through the formation of skin fat barrier.

• 한국표면공학회지
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• 제28권1호
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• pp.23-33
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• 1995

AISI 304 stainless steel has high resistance to corrosion due to the presence of a self-healing chromium oxide film on the surface, which also accounts for the difficulty in plating. Surface cleaning of this alloy is of fundamental importance in gold plating since its effectiveness puts an upper limit on the quality of the final coating. The cleaning of AISI 304 stainless steel was investigated with elimination of artificial passive oxide film and degreasing of remaining buffing wax as stearic acid. The familiar cleaning methods i.e. ultrasonic cleaning, electro-cleaning and activation treatment were fabricated in this study. Activation treatment showed best cleaning efficiency for elimination of passive oxide film among these methods, which was also confirmed by AES (Auger electron spectrometer) analysis. However, the best condition of cleaning was obtained by combining these methods. Electrocleaning time, for degreasing the stearic acid layer, was decreased with increasing amount of added KCN.