• Progress in Superconductivity
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• 제12권1호
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• pp.51-56
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• 2010

$^{13}C$ NMR (nuclear magnetic resonance) measurements have been performed to investigate the local electronic structure of a superconducting graphite intercalation compound $CaC_6$ ($T_c$ = 11.4 K). A large number of single crystals were stacked and sealed in a quartz tube for naturally abundant $^{13}C$ NMR. The spectrum, Knight shift, linewidth, and spin-lattice relaxation time $T_1$ were measured in the normal state as a function of temperature down to 80 K at 8.0 T perpendicular to the c-axis. The $^{13}C$ NMR spectrum shows a single narrow peak with a very small Knight shift. The Knight shift and the linewidth of the $^{13}C$ NMR are temperature-independent around, respectively, +0.012% and 1.2 kHz. The spin-lattice relaxation rate, $1/T_1$, is proportional to temperature confirming a Korringa behavior as for non-magnetic metals. The Korringa product is measured to be $T_1T\;=\;210\;s{\cdot}K$. From this value, the Korringa ratio is deduced to be $\xi$ = 0.73, close to unity, which suggests that the independent-electron description works well for $CaC_6$, without complications arising from correlation and many-body effects.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.316-316
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• 2010

Thin films spin-coated from solvent solutions are characterized by solution parameters and spin-coating process. In this study, performance characteristics of polymer solar cells were investigated with changing solution parameters such as solvent and additives. The phase-separation between polymer and fullerene is needed to make the percolation pathway for better transportation of hole and electron in polymer solar cells. For this reason, cooperative effects of solvent mixtures adding additives with distinct solubility have been studied recently. In this study, chlorobezene, 1, 2-dichlorbenzene, and chloroform were used as solvent. 1, 8-diiodoctaned and 1, 8-octanedithiol were used as additives and were added into poly(3-hexylthiophene-2, 5-diyl)/[6, 6]-phenyl C61 butyric acid methyl ester (P3HT/PCBM) blends. Pre-patterned ITO glass was cleaned using ultrasonication in mixed solvent with ethyl alcohol, isopropyl alcohol and acetone. PEDOT:PSS was spin-coated on to the ITO substrate at 3000rpm and was baked at $120^{\circ}C$ for 10min on the hotplate. The prepared solution was spin-coated at 1000rpm and the spin-coated thin film was dried in the Petri dishes. Al electrode was deposited on the thin film by thermal evaporation. The devices were annealed at $120^{\circ}C$ for 30min. By adding 2.5 volume percent of additives into the chlorobenzene from that bulk heterojunction films consisting of P3HT/PCBM, the power efficiency (AM 1.5G conditions) was increased from 2.16% to 2.69% and 3.12% respectively. We have investigated the effect of additives in P3HT/PCBM blends and the film characteristics and the film characteristics including J-V characteristics, absorption, photoluminescence, X-ray diffraction, and atomic force microscopy to mainly depict the morphology control by doping additives.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.238-239
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• 2010

Dimethyl sulphoxide (DMSO) is one of the widely-used secondary dopants in order to enhance the conductivity of poly(3, 4-ethylenedioxy-thiophene):poly(styrene sulfonate) (PEDOT:PSS) film. In this work, we investigated the effect of DMSO doping in to PEDOT:PSS on the electrical performance of the bulk heterojunction photovoltaics consisting of poly(3-hexylthiophene-2, 5-diyl) and phenyl-C61-butyric acid methyl ester. Correlation between the power conversion efficiency and the mechanism of improving conductivity, surface morphology, and contact properties was examined. The PEDOT:PSS films, which contain different concentration of DMSO, have been prepared and annealed at different annealing temperatures. The mixture of DMSO and PEDOT:PSS was prepared with a ratio of 1%, 5%, 15%, 25%, 35%, 45%, 55% by volume of DMSO, respectively. The DMSO-contained PEDOT:PSS solutions were stirred for 1hr at $40^{\circ}C$, then spin-coated on the ultra-sonicated glass. The spin-coated films were baked for 10min at $65^{\circ}C$, $85^{\circ}C$, and $120^{\circ}C$ in air. In order to investigate the electrical performance, P3HT:PCBM blended film was deposited with thickness of 150nm on DMSO-doped PEDOT:PSS layer. After depositing 100nm of Al, the device was post-annealed for 30min at $120^{\circ}C$ in vacuum. The fabricated cells, in this study, have been characterized by using several techniques such as UV-Visible spectrum, 4-point probe, J-V characteristics, and atomic force microscopy (AFM). The power conversion efficiency (AM 1.5G conditions) was increased from 0.91% to 2.35% by tuning DMSO doping ratio and annealing temperature. It is believed that the improved power conversion efficiency of the photovoltaics is attributed to the increased conductivity, leading to increasing short-circuit current in DMSO-doped PEDOT:PSS layer.

• Archives of Plastic Surgery
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• 제40권5호
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• pp.522-529
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• 2013

Background Despite advances in surgical techniques, sterile protocols, and perioperative antibiotic regimens, surgical site infections (SSIs) remain a significant problem. We investigated the relationship between wound classification (i.e., clean, clean/contaminated, contaminated, dirty) and SSI rates in plastic surgery. Methods We performed a retrospective review of a multi-institutional, surgical outcomes database for all patients undergoing plastic surgery procedures from 2006-2010. Patient demographics, wound classification, and 30-day outcomes were recorded and analyzed by multivariate logistic regression. Results A total of 15,289 plastic surgery cases were analyzed. The overall SSI rate was 3.00%, with superficial SSIs occurring at comparable rates across wound classes. There were similar rates of deep SSIs in the clean and clean/contaminated groups (0.64%), while rates reached over 2% in contaminated and dirty cases. Organ/space SSIs occurred in less than 1% of each wound classification. Contaminated and dirty cases were at an increased risk for deep SSIs (odds ratios, 2.81 and 2.74, respectively); however, wound classification did not appear to be a significant predictor of superficial or organ/space SSIs. Clean/contaminated, contaminated, and dirty cases were at increased risk for a postoperative complication, and contaminated and dirty cases also had higher odds of reoperation and 30-day mortality. Conclusions Analyzing a multi-center database, we found that wound classification was a significant predictor of overall complications, reoperation, and mortality, but not an adequate predictor of surgical site infections. When comparing infections for a given wound classification, plastic surgery had lower overall rates than the surgical population at large.

• 한국축산시설환경학회지
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• 제16권2호
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• pp.115-122
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• 2010

A major problem within the agricultural/farming community concerns the enormous amount of manure produced by livestock; one possible solution to this problem is to use the animal slurry as a liquid fertilizer. While there are several areas where this fertilizer could be used, one promising area of application is within chestnut tree fields. However, since most of these fields are located on slopes of varying grades and not on flat land, a different spread system is required. Generally, chemical fertilizer is spread in the chestnut field manually by hand; not only does this require a great deal of manpower it is also very difficult and hard work. In our lab experiment, we investigated the relationship between the amount of fertilizer spread and the length of pipe used at varying pressure levels. The hose in our system utilized PVC piping with evenly spaced holes for the fertilizer to dissipate. We initially found that the amount of spread was greatly reduced by reducing pipe pressure. While the difference of the amount of spread during fertilizing was not great, we did find that the reduction of the spread could be correlated to the frictional resistance of the inner lining of the pipe. Based on this, we hypothesized that an increase in pipe pressure would yield a consistent spread. Additionally, a similar outcome could be obtained by regulating the distance of the holes in the pipe and their diameter.

• 한국축산시설환경학회지
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• 제16권2호
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• pp.123-128
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• 2010

비닐하우스용 소형 액비살포기를 설계, 제작하였으며, 납작호스용 일체형과 견고한 둥근호스 분리형으로 되어 있다. 살포장치의 구성은 권취기, 유압모터, 유압실린더, 배출장치, 호스, 3점링크히치, 호스고정장치, 프레임 등으로 되어있다. 살포 시스템은 일체형과 분리형으로 나누어진다. 일반적으로 납작호스는 일체형에 사용되고 둥근호스는 분리형에 사용된다. 분리형은 좁은 공간에서 선회 등을 할 때 작업의 활동성을 개선할 수 있다. 액비살포기를 사용함으로써 작업효율을 5배 정도 높일 수 있었으며, 인력소요는 1/3로 감소되었다. 원하는 살포량에 따른 작업속도를 맞추어주면 면적당 목표 살포량을 얻을 수 있다. 관리자에 대한 작업환경이 개선되었다.

• 한국농공학회논문집
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• 제60권4호
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• pp.37-48
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• 2018

The extreme 2017 spring drought affected a large portion of central and western South Korea, and was one of the most climatologically driest spring seasons over the 1961-2016 period of record. This drought was characterized by exceptionally low precipitation, with total precipitation from January to June being 50% lower than the mean normal precipitation (1981-2010) over most of western South Korea. In this study, for the quantitative drought impact analysis, the widely-used Standardized Precipitation Index (SPI) and the statistical drought frequency are compared with observed meteorological characteristics and anomalies. According to the drought frequency analysis of monthly cumulative precipitation during January and May in 2017, Gyeonggi-do, Chungcheong-do, and Jeollanam-do areas showed more than drought frequency over 100 years. Gyeongsangnam-do area showed more than drought frequency over 200 years based on annual precipitation in 2017. The South Korean government (Ministry of Agriculture, Food and Rural Affairs (MAFRA) and Korea Rural Community Corporation (KRC)) have been operating a government-level drought monitoring system since 2016. Results from this study can be used to improve the drought monitoring applications of future drought events, as well as drought planning and preparedness in South Korea.

• 정보화정책
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• 제17권1호
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• pp.102-119
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• 2010

기존 IT 아웃소싱 관리가 기술적 인프라스트럭처의 효과적 활용에 집중되었다고 한다면 최근에는 전략적 연계와 IT 프로세스 관리에 초점을 맞추고 있다. 아웃소싱 서비스의 안정적인 공급과 정확한 평가를 위해 IT 서비스 제공 표준 프로세스를 기반으로 한 IT 서비스 관리가 주요 이슈로 떠오르고 있다. 이를 지원하기 위한 방법론으로 COBIT, ITIL 등이 활발히 도입되어 활용되고 있으며 이를 통하여 IT 아웃소싱 서비스 제공 프로세스 표준화, 관리 효과성 도출, 나아가서는 성과 향상을 목표로 하고 있다. 본 연구의 목적은 아웃소싱 서비스 제공을 위한 IT 거버넌스와 IT 서비스 제공 표준 프로세스로써 COBIT과 ITIL의 성숙도 수준이 IT 아웃소싱 성과에 미치는 영향을 탐색, 분석하는 데에 있다. 이를 위하여 증권거래소 상장 IT 아웃소싱 서비스공급사의 고객사 4개사를 대상으로 프로세스 성숙도와 아웃소싱 성과를 탐색하였다. 분석 결과, IT 서비스를 제공받는 고객사의 IT 거버넌스 수준과 서비스를 공급하는 공급사의 IT 서비스 관리 프로세스 성숙도가 아웃소싱 성과에 영향을 미치는 것으로 확인되었다.

• Safety and Health at Work
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• 제11권2호
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• pp.159-164
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• 2020

Background: This study aimed to examine the association between educational level and unable to work due to ill-health (UWdIH) among 30- to 79-year-old South Koreans. Methods: A cross-sectional nationwide survey of the 2010-2016 Korea National Health and Nutritional Evaluation Survey was used for analyses. A total of 29,930 participants aged ≥30 and < 80 years, who do not have any disability in their daily life because of health problems, were included. Educational level and reason for nonworking are self-reported with multiple choices. Multivariate logistic regression was used to examine an association between education level and UWdIH by setting those who graduated college as their final education (n = 6,997) as a baseline while controlling for potential confounding factors. Results: In the age-stratified result, the ratio of UWdIH was increased as age increases in 3 educational groups (p < .0001). There was a tendency that low-level educated [International Standard Classification of Education (0-2)] participants showed higher ratio of UWdIH than high-level educated [International Standard Classification of Education (5≤)] participants in both sexes (odds ratio: 2.54, 95% confidence interval: 2.12-3.05). Conclusion: There is a clear link between educational level and UWdIH; the less the educated, the more likely to be UWdIH. Policy priority should be given to plans that can help this vulnerable social group to work and enjoy healthy lives.

• Journal of Species Research
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• 제2권2호
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• pp.99-126
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• 2013

Amynthas diffringens (Baird, 1869) is deemed valid yet comparable to A. corticis (Kinberg, 1867) and to A. nipponicus (Beddard, 1893) or A. peregrinus (Fletcher, 1896). Its syntypes tend to more genital markings than usual as shown for variable specimens from Japan, Korea, and Australasia that comply genetically with either of two A. corticis spp. groups. A. diffringens type-locality was UK hothouses yet closest specimens appear in part of A. heteropodus (Goto & Hatai, 1899) (=A. corticis) from Japan. Japanese Amynthas divergens (Michaelsen, 1892) is restored based on its serrate intestinal caeca. Meanwhile, the lectotype of Amynthas pingi (Stephenson, 1925) is deemed a synonym of A. carnosus (Goto & Hatai, 1899) compliant with Kobayashi's (1936) types III & II. Erstwhile A. pingi synonym A. fornicatus (Gates, 1925) is again included, but A. hongkongensis (Michaelsen, 1910) and A. chungkingensis (Chen, 1936) are provisionally retained whilst A. carnosa lichuanensis Wang & Qiu, 2005 is given separate species status. A new Korean taxon is proposed as A. carnosus naribunji sub-sp. nov. and two replacement names are provided: A. zhuya nom. nov. for homonym A. montanus Qiu & Sun, 2012 from Hainan and A. yizhou for A. carnosus sensu Shen et al., 2005 from Taiwan. No attempt is made to fully resolve numerous Japanese synonyms of A. carnosus [eg Ishizuka's (2001) invista, subterranea, subalpina, umbrosa, mutabilis, nubicola, plus A. nonmonticolus Blakemore, 2010] nor Korean synonyms [eg kyamikia Kobayashi, 1934, monstrifera Kobayashi, 1936 and murayamai Kobayashi, 1938, sangyeoli, youngtai (with segments miscounted), kimhaeiensis, sinsiensis and baemsagolensis - all names by Hong & James (2001) plus ?A. sangumburi Hong & Kim, 2002 (its segments miscounted too)] also A. fuscus Qiu & Sun, 2012 from Hainan and Taiwanese monsoonus James et al., 2005 plus A. penpuensis Shen et al., 2003 and A. taiwumontis Shen et al., 2013 syns. nov.. All synonyms remain in the currently defined A. carnosus pending full revisons although several may eventually comply with parts of prior A. corticis s. lato.