• 제목/요약/키워드: elimination condition

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A Study on Harmonic Elimination of FC-TCR in Power System (전력계통에 있어서 FC - TCR 장치의 고조파 제어에 관한 연구)

  • Kim, Joon-Hyun;Kim, Young-Man;Lee, Seung-Joo
    • Proceedings of the KIEE Conference
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    • 1988.11a
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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.

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A Study on Characteristics of De-electrification and Discharge of Self-Discharged Electrostatic Reducer (자기방전식제건기에 의한 대전물체의 제전 및 방전특성)

  • 박수덕;이동훈
    • Journal of the Korean Society of Safety
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    • v.10 no.2
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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.

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Effects of the Colloid/Interface Variables on Densification and Pore Elimination of Zirconia (콜로이드/계면변수가 Zirconia의 치밀화와 기공제거에 미치는 영향)

  • 장현명;한규호;이기강;정한남
    • Journal of the Korean Ceramic Society
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    • v.27 no.2
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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.

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A Study on the Elimination of Integrator in DM Filters (DM 필터에서의 적분기제거에 관한 연구)

  • Shin, Jae Ho;Lee, Chong Kak
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.23 no.3
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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.

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Base-Catalyzed Rearrangement of Some 1,3-Oxathiolane Sulfoxides: Mechanistic Viewpoint of the Sigmatropic and Elimination Reactions

  • Hahn, Hoh-Gyu;Nam, Kee-Dal;Cheon, Seung-Hoon
    • Bulletin of the Korean Chemical Society
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    • v.25 no.9
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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.

Accumulation of Food Wastes Liquid Fertilizer using Reverse Osmosis Membrane System (역삼투막을 이용한 음식폐기물 액비의 농축)

  • Cha, Gi-Cheol;Hwang, Myoung-Goo;Lee, Myung-Gyu;Tae, Min-Ho
    • Journal of Korean Society on Water Environment
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    • v.18 no.2
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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).

A study on the explosion proof by the electric discharge on voltage application type (전압인가식 제전기의 방폭화에 관한 연구)

  • Lee Chun Ha;Kim Jum Ho;Park Min Young
    • Journal of the Korean Institute of Gas
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    • v.8 no.4 s.25
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    • pp.62-69
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    • 2004
  • It is necessary to eliminate the electric static for the prevention of disasters by electric static discharge, the improvement of production efficiency, the protection of a sensitive electronic devices in the variable manufacturing processes. Then it is handled for elimination of electric static in the painting plant, the film manufacturing plant, the producing semi-conductor factory. This study described on the ideal condition of electric static elimination efficiency by changing of the length of voltage input type eliminator's bar, the length of copper pipe and the gap of electrode and the existence of explosion by inflammable gas with that conditions. As the result, the electric static elimination efficiency has the most ideal value at the 8-11(mm) gap of the earth electrode and needle type electrode each elimination bar and there is not explode at the explosive experiment of inflammable gas with the ideal elimination bar. We can consider that there are some data which are needed for elimination efficiency and it will be able to protect the occurrence of explosion accident inflammable nas in the industrial fields.

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A fast full search algorithm for multiple reference image motion estimation (다중 참조 영상 움직임 추정을 위한 고속 전역탐색법)

  • Kang Hyun-Soo;Park Seong-Mo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.43 no.1 s.307
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    • pp.1-8
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    • 2006
  • This paper presents a fast full search algorithm for motion estimation applicable to multiple reference images. The proposed method is an extended version of the rate constrained successive elimination algorithm (RSEA) for multiple reference frame applications. We will show that motion estimation for the reference images temporally preceding the first reference image can be less intensive in computation compared with that for the first reference image. for computational reduction, we will drive a new condition to lead the smaller number of candidate blocks for the best matched block. Simulation results explain that our method reduces computation complexity although it has the same quality as RSEA.

Effect of Th2 Differentiation Control through Formation of Skin Fat Barrier on Coptidis Rhizoma & Glycyrrhiza Uralensis extract (황련감초 추출물의 상피지방장벽 생성을 통한 Th2 분화 조절)

  • Park, Beom Chan;Ahn, Sang Hyun;Seo, Il Bok;Cheon, Jin Hong;Kim, Ki Bong
    • The Journal of Pediatrics of Korean Medicine
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    • v.34 no.3
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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.

A Study on the Cleaning of AISI 304 Stainless Steel Surface for Gold Plating (금도금을 위한 AISI 304 스테인레스강 표면의 세정)

  • 한범석;장현구
    • Journal of the Korean institute of surface engineering
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    • v.28 no.1
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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.

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