• 제목/요약/키워드: optimum condition

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웨이퍼 폴리싱 공정의 회전속도와 진폭속도에 따른 가공특성 연구 (A Study on the Characteristics of a Wafer-Polishing Process at Various Machining and Oscillation Speed)

  • 이은상;이상균;김성현;원종구
    • 한국기계가공학회지
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    • 제11권1호
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    • pp.1-6
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    • 2012
  • The polishing of silicon wafers has an important role in semiconductor manufacturing. Generally, getting a flat surface such as a mirror is the purpose of the process. The wafer surface roughness is affected by many variables such as the characteristics of the carrier head unit, operation, speed, the pad and slurry temperature. Optimum process conditions for experimental temperature, pH value, down-force, slurry ratio are investigated, time is used as a fixed factor. This study carried out a series of experiments at varying platen, chuck rpm and oscillation cpm taking particular note of the difference between the rpm and the affect it has on the surface roughness. In this experiment determine the optimum conditions for polishing silicone wafers.

정밀연삭기의 전해드레싱 시스템 개발사례 (Development of Grinding Dressing System by Using Inprocess Electrelytic Dressing)

  • 김정두
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1998년도 춘계학술대회 논문집
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    • pp.196-202
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    • 1998
  • Recently, developments in the frontier industry have brought a rapid increase in the use of brittle materials such as silicon wafer, ferrite, sintered carbide, MgO single crystal and die steel. Because of high hardness and brittleness the cracking and chipping are apt to generate in the grinding of brittle materials, but have replaced gradually the high precision grinding. In this study, the optimum system of in-process electrolytic dressing controlled by computer was developed for improving the defects, and could maintain the optimum dressing condition at all times. The control of in-process dressing was simplified using this system, was able to maintain a stable dressing current and was unrelated to the change of dressing condition according to the variation of gap and oxide layer. Therefore, the optimum in-process electrolytic dressing system was constructed and the analysis of grinding mechanism with this system was studied.

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솔잎 가루 첨가 냉동 쿠키의 제조 배합비의 최적화 (Optimization of Iced cookiess with the Addition of Pine leaf Powder)

  • 진소연;주나미;한영실
    • 한국식품조리과학회지
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    • 제22권2호
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    • pp.164-172
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    • 2006
  • The purpose of this study was to find the optimal mixing condition of three different amounts of pine leaf powder, butter and sugar for preparation of pine leaf cookies. The optimum mixing condition for pine leaf cookies was optimized by response surface methodology The optimum mixing rates of pine leaf powder, butter and sugar were 8.6 g, 252.8 g and 154.1 g for color, 8.4 g, 240.7 g and 149.8 g for appearance, 8.8 g, 246.5 g and 154.7 g for flavor and 10.9 g, 277.1 g and 134.6 g for texture respectively. The optimum mixture ratio which fulfilled all items was pine leaf powder 9.4 g, butter 270.5 g and sugar 141 g.

최적화 기법을 이용한 3차원 트러스 구조물의 설계자동화 (Design Automatization of Space Truss Structure Using Optimizations Technique)

  • 최은규;임기식;이병해
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1993년도 가을 학술발표회논문집
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    • pp.81-90
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    • 1993
  • The optimum design of a structure requires the determination of the economical member size and shape of the structure which satisfies the design condition and function. In this study, the process of design automatization of three-dimensional truss structure introduces the optimization technique tests its application in the design automatization, proposes its application method and applies the example structure of the parabolic antenna truss. Using the Formex Algebra of configuration function, the structure's mesh-generation is automatized. By using the program developed in this study, the input member array, member size and load condition designer can generate the input data file for the structure analysis and optimum design. This study is aimed at the development of a design automatization system that search for tile optimum value of a structure design by observing the structure's sensitivity from the modification of member array and member property.

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국산 SPS5 스프링강의 마찰용접에 관한 연구 (A Study on Friction Welding of Localized SPS5 Spring Steel)

  • 정순억
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집A
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    • pp.803-808
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    • 2000
  • This thesis studied whether friction welding of SPSS, localized torsion bar material could be accomplished or not. And then optimum welding conditions were examined and leaded through tensile, impact, torsion and hardness test after postweld heat treatment of the actual field condition. Obtained results were as follows; Linear relationship was existed between heating time and total upset, and a quadratic equation model could be made between tensile strength and heating time. Optimum welding conditions with fine structure were as follows in case total upset(U)=8.5mm; the number of rotations(n)=2,000 rpm, heating pressure($p_1$)=80MPa, upset pressure($p_2$)=200MPa, heating time($t_1$)=4sec, upset time($t_2$)=3 sec.

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재한 중국 조선족의 생활 형태 및 삶의 질에 관한 연구 (A Study on Real-Life Conditions and Quality of Life among Korean-Chinese in Korea)

  • 최덕경
    • 가족자원경영과 정책
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    • 제5권1호
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    • pp.1-13
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    • 2001
  • The purpose of this study was not only to identify real-life conditions of Korean-Chinese in Korea(clothing habits, eating habits, housing habits, economic life and leisure activities) but also to reveal the related variables that shall affect life quality. The subjects were selected from Korean-Chinese in Korea related to ‘Compatriots House’. The survey was conducted from June 20th to July 5th, 2000. A total of 225 questionnaires out of 350 were used as the final data analysis. All data were analyzed using the SAS/PC for frequency, percentage, F-test and Regression analysis. The study revealed the following results. 1. Significant differences were found in life quality of Korean-Chinese in Korea according to age(p<.05), optimum income (p<.001), health condition(p<.001), education level(p<.005), and entry motivation(p<.05). 2. Variable such as optimum income(β=.334) education level(β=-.190), monthly income(β=.170), health condition(β=.151), and self-esteem(β=.133) affected life quality of Korean-Chinese in Korea. Korean-Chinese’s life quality was explained by these variable(35%). The optimum income variable was the primary influential factor.

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쇼트피닝 가공에 의한 자동차용 Drive Plate의 내구성 향상 (A Study on the Improvement of the Durability of Drive Plate in Automobiles by Shot Peening)

  • 정성균;이국진;이동선;이재헌
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2005년도 춘계학술대회 논문집
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    • pp.191-196
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    • 2005
  • The effects of shot peening on the fatigue strength of SK-5M steel is investigated by experiment. The shot peening process is investigated optimum peening condition by changing impeller speed and exposure time. Bending fatigue test is accomplished to investigate the effect of optimum peening condition on the fatigue characteristics. As exposure time is increased, fatigue life in high stress is increased in early stage, become the maximum from 60 to 100 seconds, and then is decreased. Observing fracture surface through SEM after fatigue test, we can see clear configuration of cracks and peening layer.

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쇼트피닝 가공에 의한 Al 7075-T6의 피로특성에 관한 연구 (A Study on the Fatigue Characteristics of Al 7075-T6 by Shot Peening)

  • 김태형;정성균;신용승
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2002년도 추계학술대회 논문집
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    • pp.335-340
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    • 2002
  • The shot peening process is most often used to improve fatigue properties of metal parts. In order to achieve optimum, repeatable and reliable fatigue enhancement from the shot peening process, the important shot peening parameters must be controlled. In this paper, the optimum shot peening condition is investigated. Rotate bending fatigue test was accomplished to investigate the effects of shot peening on the fatigue strength. Experimental results show that the fatigue strength was tremendously increased by optimum peening condition. But the fatigue strength was decreased by under peening or over peening.

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쥐의 태아 흉선 조직 배양을 이용한 면역조절제 검색방법 확립 (The Screening Condition for the Immune Regulatory Responsor Using Mouse Fetal Thymic Organ Culture)

  • 이승각;송민동;이광호
    • 생약학회지
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    • 제28권4호
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    • pp.286-292
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    • 1997
  • We studied the screening condition for immune regulatory responsor. We focused on the T-lymphocytes leer this purpose. Mouse fetal thymic organ culture (FTOC) system and flow cytometric analysis were mainly used in this experiment. Even if FTOC is carried out in vivo condition, the pattern of thymic development in the condition of FTOC is similar to that of in vivo condition. In this regard, FTOC system might be very powerful tool to screen the immune regulator, especially concerning on T cells. To establish the optimum condition of FTOC to screen the Immune regulator, we focused on the optimum amount of dose and culture period. The cell number and surface antigens on T cells were also analysed by using hemacytometer and flow cytometer. To monitor the differentiation event, anti-CD3, anti-CD4 and anti-CD8 antibodies were used. Alkoxyglycerol and Phellodendri Cortex were used fur positive and negative control, respectively. Astragalus membranceus was used as test sample. From our analysis, we reached to conclusions that the best dose of extract is $50\;{\mu}g/ml$ of culture medium, the best culture period is for 9 days, and ethanol used as solvent has no toxicity to FTOC.

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GC/MS를 이용한 잎담배 중 알칼로이드 함량 분석 (Determination of Nicotine and Other Minor Alkaloids in Tobacco Leaves by GC/MS)

  • 이정민;민혜정;김용하;이문수
    • 한국연초학회지
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    • 제27권1호
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    • pp.100-106
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    • 2005
  • To obtain the optimum condition for analysis of 10 alkaloids in tobacco leaves, such as nicotine, nornicotine, anatabine, anabasine, myosmine, cotinine, 2,3'-dipyridyl, $\beta-nicotyrine,\;\beta-nornicotyrine\;and\;\beta-formylnornicotin$, 5 types of extraction method were investigated by GC-FID and GC/MS. The optimum condition of alkaloid extraction was achieved by using methanol:dichloromethane(1:3, v/v) after NaOH treatment. The use of mass selective detector (MSD) provided unambiguous nicotine related alkaloid analysis. Alkaloids in various tobacco leaves were extracted with the optimum extraction condition and quantified by GC/MS/SIM mode. Compared with concentrations of alkaloids among the various tobacco leaves, the concentration of alkaloids was generally in the order burley > flue-cured > oriental tobacco. In flue-cured tobacco leaves, the order of concentration of alkaloids was nicotine > anatabine > nornicotine > $\beta-nicotyrine\;>\;\beta-formylnornicotine\; >\;myosmine\;>\;2,3'-dipyridyl\;>\;cotinine\;>\;anabasine\;>\;\beta-nornicotyrine$. However, in the case of burley and oriental tobacco leaves, the concentration of nornicotine was higher than that of anatabine.