• 제목/요약/키워드: Jeon Yong Soon

검색결과 201건 처리시간 0.03초

Preparation of Yba2Cu3Ox Superconductor Prepared with Additives of PbO and Ag2O

  • Chu, Soon-Nam;Park, Jung-Cheul;Jeon, Yong-Woo
    • Transactions on Electrical and Electronic Materials
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    • 제10권1호
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    • pp.31-34
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    • 2009
  • The improvement of preparation process of ${YBa_2}{Cu_3}{O_x}$ superconductor and its conducting properties is important for practical applications. In this study, the additives such as $Ag_{2}O$ and PbO were used to improve the preparation conditions of ${YBa_2}{Cu_3}{O_x}$ superconducting bulk samples and the properties of ${YBa_2}{Cu_3}{O_x}$ superconductors prepared with powders using sol-gel method and solid state reaction method were studied. The effects of the different powders and the additives to the density, grain alignment, and porosity of samples, that affect the critical current density of superconductor, also have been investigated. It is found that the properties of ${YBa_2}{Cu_3}{O_x}$ prepared with sol-gel synthesized powder and the additives showed better superconductivities than those of conventionally prepared superconductors.

LED 프로젝터 방열용 히트싱크의 성능평가 (Performance Evaluation of Heat Sink for Cooling of LED Projector)

  • 이경용;최영석;전동순;김선창;손광은
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.1167-1171
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    • 2008
  • The flow and thermal performance of the skiving and louver fin type heat sinks for the cooling system of the small LED projector were experimentally evaluated. A small fan tester based on AMCA standards was used to control and measure the air flow rate into the heat sink. Three heat blocks were used to simulate the heat and light sources(red, green and blue) of the small LED projector. We measured the pressure drop, temperatures and input power at the specific air flow rate and discussed those results. As a result, it is found that the louver fin type heat sink has higher pressure drop and lower thermal resistance than the skiving type. From the comparison of the temperature of the heat block between skiving and louver fin type, the louver fin type heat sink was found to be more suitable for cooling the high power heat source than skiving type. The thermal performance of the fan-sink(louver fin type) system was discussed with the picture taken by a thermal video.

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염색체 마디 추출을 위한 최적타원 추정기법 (The Optimal Ellipse Estimation Method for Chromosome Bands Extraction)

  • 이상렬;이권순;전계록;장용훈;엄상희
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1995년도 춘계학술대회
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    • pp.227-229
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    • 1995
  • This paper attempts to examine an optimal method for the chromosome specific vector extraction. Usually, represented method are used with a line segmentation on a chromosome Image. It is not Inaccurate but also needs a long time for the analysis. This paper purpose to aquire specific vector in the image with a using optimal ellipse estimation method. Normally, shapes of chromosomes are curved and too difficult to analyze automatically. A chromosome has a lot of band which looks like an ellipse. If we can estimate their bands with an ellipse, we can reconstruct the sample Which Is straight and can be analyzed easily. We have rearranged a chromosome Image with above proposed. Result shows a reconstructed sample which Is simple for chromosome analysis.

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Color Variation Improvement by Introducing Double Emission Layers in WPLEDs

  • Kwon, Soon-Kab;Lee, Yong-Kyun;Park, Tae-Jin;Jeong, Su-Hyeon;Jeon, Woo-Sik;Kwon, Jang-Hyuk;Jang, Jin
    • Journal of Information Display
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    • 제7권3호
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    • pp.19-22
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    • 2006
  • White polymeric light-emitting devices (WPLEDs) have been fabricated from polyfluorene-based (PFO) blue and MEH-PPV polymer blending systems. A device structure of ITO / PEDOT:PSS / Blending polymer / Blue polymer / LiF / Al was employed. This structure of double emission layers showed significant improvement of white color shift phenomenon. A current efficiency of 4.67 cd/A (3,900 $cd/m^{2}$, 6.4 V) and a brightness value of 17,600 $cd/m^{2}$ at 9.4 V with (0.34, 0.35) CIE coordinates at 5 V and (0.29, 0.29) at 9 V were achieved achieved.

유연성 전자소자 적용을 위한 BNO박막의 저온화학기상증착 (Low Temperature Chemical Vapor Deposition of BNO Thin Films for Flexible Electronic Device Applications)

  • 전상용;성낙진;윤순길
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.42-42
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    • 2007
  • In the future, electronic components will be integrated on flexible polymer substrates and then miniaturized by thin films using suitable thin film technologies. In this article, the concept of a room temperature CVD is demonstrated using $Bi_3NbO_7$ (BNO) films with a cubic fluorite structure and their structural and electrical properties were investigated in films deposited without substrate heating. Effects of substrate temperature on electrical properties of BNO films were also studied. Films deposited without substrate heating (real temperature of $50^{\circ}C$) show partially crystallized BNO single phases with grain size of approximately 6.5 nm. Their dielectric and leakage properties are comparable to those of films deposited by pulsed laser deposition at room temperature. The concept of room temperature CVD will become a new paradigm in the deposition of dielectric thin films for flexible electron device applications.

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염료감응형 태양전지의 $TiO_2$ 박막에 바인더에 의한 투과율 특성 (Transmissivity Characteristics by Binder Contents in the $TiO_2$ for Dye-sensitized Solar Cells)

  • 박정철;추순남;이우식;전용우;이성준;홍상진
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.138-139
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    • 2007
  • In this paper, we have studied the optical properties of $TiO_2$ thin film by adding the additives of PEG, PEO and both of them. As a variable amount of additives was added into $TiO_2$, the transmittance of $TiO_2$ thin film was decreased. When the 20 wt% of additives mixed with PEG and PEO was added into $TiO_2$, the transmittance of $TiO_2$ thin film showed higher than that of 10 wt% of additives mixed with PEG and PEO. As a results, we could conclude that the additives makes pore in $TiO_2$ thin film and it improves the transmittance of $TiO_2$ thin film.

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보폐원탕(補肺元湯)이 면역반응에 미치는 영향 (Effect of Bopaewon-tang on Immune Reaction)

  • 전용근;이경아;임재윤;권진;장인수;송정모;은재순
    • 동의생리병리학회지
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    • 제20권1호
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    • pp.125-130
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    • 2006
  • The purpose of this research was to investigate the effects of Bopaewon-tang (BT) on immune reaction in mice. BT (500 mg/kg, p.o.) increased the viability of thymocytes, but decreased the viability of splenocytes in vivo. BT enhanced the population of $CD4^+$cells in thymocytes and enhanced the population of $Thy1^+$ cells in splenocytes and splenic $CD8^+$ cells. Also, BT decreased the production of IL-4 from splenocytes. Furthermore, BT enhanced the production of nitric oxide and the phagocytic activity of peritoneal macrophages. These results suggest that BT enhances the immune response via activation of thymocytes and macrophages.

고종시 감껍질의 추출조건에 따른 항산화 활성 (Changes in the Antioxidant Potential of Persimmon Peel Extracts Prepared by Different Extraction Methods)

  • 정명진;진순우;화성용;방희옥;한동문;전지영;화세경
    • 한국약용작물학회지
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    • 제27권3호
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    • pp.186-193
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    • 2019
  • Background: Astringent persimmon (Diospyros kaki Thunb. cv. Kojongsi) peels are by-products of dried persimmons. This study aimed to evaluate the antioxidant activities of Kojongsi persimmon peel (KPP) extracts prepared by 15 different extraction methods: 5 heating durations (0.5 - 2.5 h) at 3 heating temperatures (50, 70, and $90^{\circ}C$). Methods and Results: An increase in heating temperature increased the antioxidant effect of KPP extracts. Those prepared by heating at 1 h had the highest total phenol content, regardless of the heating temperature. In addition, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and cell-protective effects against $H_2O_2-induced$ oxidative stress were dependent on the total phenol contents of the extract. However, the KPP-induced increased in catalase expression was dependent on heating temperature and duration. Conclusions: These results suggest that extraction by heating at $90^{\circ}C$ for 1 h may enhance KPP's antioxidant effects, which mainly involve non-enzymatic antioxidant systems.

헤도닉 가격 모형을 이용한 즉석밥 속성가치에 대한 연구 (A Study on the Attribute Value of Instant Rice Using Hedonic Price Model)

  • 권순성;전혜빈;김정환;이지용
    • 한국유기농업학회지
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    • 제30권2호
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    • pp.191-206
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    • 2022
  • Rice has prevailed as a staple food in South Korea. Rice consumption has sharply shrunk nowadays. In the wake of COVID-19 Shock and the "untact" era, the instant rice market has significantly grown, and there is a possibility of solving the shrinking consumption of domestic rice. This study contributes to the development of rice consumption promotion strategies by examining the factors of purchasing instant rice based on the Hedonic Price Methodology. In particular, given the increase in online market, this study compares attribute values of product characteristics between online and offline markets. The empirical results show that calorie, brand, organic and functional products have positive effects on instant rice prices. The rate of carbohydrate, the PB and bundle attributes have negative effects on instant rice prices. The results also show that the magnitude of brand, bundle and PB attribute values are bigger in offline market while that of the number of multigrain attribute value is relatively bigger in online market. The organic attribute value is important regardless of marketing channels.

Radical Scavenging Effects and Protective Effect of Spatholobus suberectus against $CCl_4-induced$ Liver Damage in Rats

  • Jeon, Hoon;Cha, Dong-Seok;Ko, Sung-Hoon;Park, Ho-Jun;Lee, Yong-Jae;Lee, Se-Youn;Lim, Jong-Pil;Shin, Tae-Yong;Oh, Chan-Ho;Eun, Jae-Soon;Yang, Jae-Heon;Kim, Dae-Keun;Bu, Young-Min;Kim, Sung-Zoo
    • Natural Product Sciences
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    • 제14권2호
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    • pp.127-130
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    • 2008
  • In the present study, we obtained an extract from the dried stem of Spatholobus suberectus Dunn by using 85% methanol (MeOH extract of S. suberectus; MSS) and investigated its radical scavenging effects in vitro and its protective effect against $CCl_4-induced$ liver damage in rats. MSS scavenged the 1,1-diphenyl-2- picrylhydrazyl radical almost completely and inhibited $FeSO_4-induced$ lipid peroxidation (LPO) in the liver homogenate. Oral administration of MSS significantly reduced the serum glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, and alkaline phosphatase and inhibited LPO in the liver tissue after $CCl_4$ treatment in rats. These results suggest that S. suberectus could be a candidate agent for the treatment of diseases related to oxidative stress.