• 한국신뢰성학회지:신뢰성응용연구
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• 제14권4호
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• pp.213-219
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• 2014

Wind turbine, which is attracting part of the renewable energy and is researching continuously, is going to be large size for high efficiency. There is a yaw system rotating the nacelle, weighted about 600 tons, to be perpendicular with the wind direction blowing in the large wind turbine. The wind turbine is focusing on the reliability improvement because working environment effect is bigger than any other points and specially, the reliability improvement of the yaw drive is required by the customer because it is the key component of the wind turbine. Because of this, the establishment of criteria for yaw drive is required because yaw drive system is the part of the wind turbine closely related with ensuring the reliability. So, this study did the failure analysis of the yaw drive system, which is consisted with 10 sets of yaw drives through researching and analyzing the site conditions. Also this study designed the life test method based on the failure analysis and working condition of the yaw drive. To design the accelerated life test of the yaw drive, this study reviewed the torque, lubrication condition, and frequency of use and etc. Finally, this selected the torque as the acceleration factor which is affected mainly to the system and also, the test equipment was developed based on the requirement of the life and performance test.

• 한국환경복원기술학회지
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• 제18권6호
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• pp.135-149
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• 2015

Korean fir(Abies koreana E.H.Wilson 1920), endemic tree species of Korean peninsula, is considered as vulnerable and endangered species to recent rapid environmental changes such as land use and climate change. There are limited activities and efforts to find natural habitats of Korean fir for conservation of the species and habitats. In this study, by applying SDMs (Species Distribution Models) based on climate and topographic factors of Korean fir, we developed Korean fir's predicted distribution model and explored novel natural habitats. In Mt. Shinbulsan, Youngnam region and Mt. Songnisan, we could find korean fir's two novel habitat and the former was the warmest($13^{\circ}C$ in annual mean temperature), the driest(1,200mm~1,600mm in annual rainfall) and relatively low altitude environment among Korean fir's habitats in Korea. The result of SDMs did not include mountain areas of Gangwon-do as habitats of A. nephrolepis, because there were different contributions of key habitat environment factors, summer rainfall, winter mean temperature and winter rainfall, between A. koreana and A. nephrolepis. Our results raise modification of other distribution models on Korean fir. Novel habitat of Korean fir in Mt. Shinbulsan revealed similar habitat affinity of the species, ridgy and rocky site, with other habitats in Korea. Our results also suggest potential areas for creation of Korea fir's alternative habitats through species reintroduction in landscape and ecosystem level.

• 대한간호학회지
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• 제29권5호
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• pp.1155-1166
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• 1999

The purpose of this study was to investigate the residents' opinions about community mental health in the Taegu-Kyungpuk area for the future development of a community mental health program and model appropriate for Korea, The subjects were 152 residents in the Taegu - Kyungpuk area. In July 1999, the data was collected using a convenience sample technique. Mental health status was significantly different for the level of occupational advantage(x$^2$＝15.684, p＜.05) and physical health(x$^2$＝39.262, p＜.000). Factor structure for mental health problems with the percentage of variance was as follows. optimistic view(27.518), dark view(10.758), mastery(6.200), discomfiture(6.101) and life style(5.641). Most of the respondents(92.1%) took the mental health problems seriously. The serious aspects of the mental health problem were found to be epilepsy, mental retardation, neurosis and schizophrenia respectively. Concerning about the view of community mental health, most of the respondents answered that the a C.M.H.C. was ‘useful and urgent’ concerning the need for C.M.H,(77.6%). They answered positively on the utilization of C.M.H.C(75.7% ) and preferred the separately new community mental heath center. A psychiatrist was preferred as the key person in charge(44.1%). If community mental health centers were established in a community health center, they answered that the expected major problem would be quality control of care(44.7%). They preferred the psychiatrist's office as the recommended agency for the insane(44.7%). Opinions of the asylum system were found very negative in respect to psychiatric therapy and humanitarianism. The results of this study will help establish a relevant model for this community as the primary site for a community-based mental health model.

• Bulletin of the Korean Chemical Society
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• 제26권12호
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• pp.1969-1974
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• 2005

Composite systems of $Eu(phen)_2Cl_3{(H_2O)}_2$, Eu(DN-bpy)$(phen)Cl_3{(H_2O)}_2$ and Eu(DB-bpy)$(phen)Cl_3{(H_2O)}_2$ (DNbpy: $4,4^\prime$-Dinonyl-$2,2^\prime$-dipyridyl; DB-bpy: $4,4^\prime$-Di-tert-butyl-$2,2^\prime$-dipyridyl) with crown ethers of Benzo-15-crown-5 (B15C5), Benzo-18-crown-6 (B18C6), 18-crown-6 (18C6), Dibenzo-18-crown-6 (DB18C6) and Dibenzo-24-crown-8 (DB24C8) were fabricated successfully and characterized by using photoluminescent spectroscopy and luminescent lifetime measurements. All composites formed show high luminescence mainly in red region. It was found that the heterocyclic ligands such as phen, DN-bpy and DB-bpy as well as the crown ethers have great influences on the photoluminescent properties of $Eu^{3+}$ ion. The environment around $Eu^{3+}$ ion in the composite systems changes greatly,presumably the variation of the first coordination sphere. The $Eu^{3+}$ ion occupies higher symmetrical environment and in more than one kind of symmetrical site in the composite systems studied in this work.

• 대한영양사협회학술지
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• 제14권1호
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• pp.23-35
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• 2008

Improved nutritional intake contributes to maintaining health and quality of life in elderly population and also reducing individual and social medical costs. Most of nutrition assistance programs for elderly, such as congregate or home-delivered meal programs, are not currently serviced in rural communities mainly due to low cost efficiency of program operation. However, the needs and necessity of such programs are presumed to be higher in rural area where the population density of elderly at nutritional risk is relatively high. Therefore, the purpose of this study was to develop a community-based meal program for the rural elderly. In 2007, four rural communities located in Jeon-Nam province were selected and the pilot meal program was applied for three months. Following are key features of the meal program model developed in this study: 1) meal production and service are operated by elderly participants to overcome the voluntary personnel shortage 2) utilization of locally-produced foods is maximized to reduce the meal cost, 3) traditional cooking methods are applied to adjust the food preference of elderly, and 4) foods are serviced on site to minimize the food safety problem possibly caused by delivery process. The pilot programs resulted in high satisfaction with the programs of participating elderly. The community-based meal program model developed in this study is expected to be used as an effective nutrition and health intervention model for the rural elderly.

• 한국환경성돌연변이발암원학회지
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• 제22권3호
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• pp.175-182
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• 2002

Endocrine disruptors (EDs) are the chemicals that affect endocrine systems through activation or inhibition of steroid hormone response. It is necessary to have a good system to evaluate rapidly and accurately endocrine-disrupting activities of suspected chemicals and their degradation products. The key targets of EDs are nuclear hormone receptors, which bind to steroid hormones and regulate their gene transcription. We constructed a co-expression system of Gal4p DNA binding domain (DBD)- ligand binding domain of human estrogen receptor $\alpha$ or $\beta$, and Gal4p transactivation domain (TAD)-co-activator AIB-1, SRC-1 or TIF-2 in Saccharomyces cerevisiae with a chromosome-integrated lacZ reporter gene under the control of CYC1 promoter and Gal4p binding site (GAL4 upstream activating sequence, GAL4$_{UAS}$). Expression of this reporter gene was dependent on the presence of estrogen or EDs in the culture medium. We found that the two-hybrid system with combination of the hER$\beta$ LBD and co-activator SRC-1 was most effective in the xenoestrogen-dependent induction of reporter activity. The extent of transcriptional activation by those chemicals correlated with their estrogenic activities measured by other assay systems, indicating that this assay system is efficient and reliable for measuring estrogenic activity. The data in this research demonstrated that the yeast detection system using steroid hormone receptor and co-activator is a useful tool for identifying chemicals that interact with steroid receptors.s.

• International Journal of Oral Biology
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• 제31권1호
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• pp.1-6
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• 2006

The primary cause of periodontitis is plaque-associated anaerobic gram-negative bacteria. As shown in the patients with defects in the number or function of neutrophils, innate immunity plays an important role in resistance to bacterial infection and periodontitis. Toll-like receptor 4(TLR4) is one of the key receptors that recognize the molecular patterns of microbes and initiate innate immune response. To understand the role of TLR4 in the pathogenesis of periodontitis, we investigated whether Asp299Gly of TLR4 mutation is associated with periodontitis in Korean population. Subjects for this study included 90 healthy subjects and 98 periodontitis patients. The Asp299Gly mutation was screened by PCR-Restriction Fragment Length Polymorphism(RFLP) of genomic DNA from blood cells using a primer that creates a NcoI restriction site only in the mutant allele. The Asp299Gly mutation was not found in all subjects tested. Our results suggest that the Asp299Gly mutation of TLR4 is very rare in a Korean population. Further mutation screening may be required to determine the role of TLR4 in the pathogenesis of periodontitis.

• 한국전자파학회논문지
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• 제24권8호
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• pp.791-797
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• 2013

본 논문은 자동차 부품의 EMC 규격인 CISPR25의 ALSE 검증 방법에 관하여 새로운 제안을 하였다. CISPR-16은 NSA와 VSWR 방법을 이용하여 챔버 성능을 검증하도록 하고 있다. 그러나 CISPR25의 ALSE는 아직까지 챔버 검증에 관한 표준 방법이 없다. 본 논문은 이러한 관점에서 CISPR D/A JTF에서 논의가 되고 있는 롱-와이어 안테나 방식의 검증 방법을 기반으로 개선된 성능 검증 방법을 제안하고자 한다. 기존에 논의된 롱-와이어 안테나 방식은 길이 500 mm의 안테나를 제안했지만, 본 논문에서는 1,700 mm 안테나 길이를 제안하였으며, 정합 조건에 따른 영향도 평가와 기존에 제안된 방법과 관련된 문제점 및 중요 파라미터들에 관하여 검증 및 개선 방안을 제안하였다.

• 한국병원경영학회지
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• 제14권4호
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• pp.1-24
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• 2009

The purpose of this study was to find out the differences and relationships among balanced strategy, coordinating and learning mechanism, and perceived performance of hospitals in Korea, and provide some directions to establish effective strategic management of hospital. Measure items on balanced strategy, coordinating and learning mechanism, and perceived performance were developed from previous studies. Questionnaire was sent and received through Internet site and e-mail during May, 2008. Data were collected from key informant in each institutions, and analyzed using frequency analysis, T-test, ANOVA, correlation and regression analysis. The major findings of this study were as follows: 1. The level of strategic selection and external learning mechanism of private hospital was lower than that of medical corporation, and others corporation hospital. 2. There was little difference between hospitals in metropolitan and those in small cities. 3. Hospitals that have under 100 beds were statistically lower level in strategic selection and external learning mechanism than hospitals has over 100 beds. 4. Formal coordinating and external learning mechanism, and foundation form(medical corporation) were significantly influenced on profitability from specialized field. 5. Strategic selection and adaptation mechanism were significantly affected on total profitability. 6. Strategic selection and external learning mechanism were significantly influenced on competitive power around its local market. Hospitals that are to be competitive by specialization should have to establish mechanism for management such as balanced strategy, coordinating and learning mechanism.

• BMB Reports
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• 제32권3호
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• pp.254-258
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• 1999

The NADPH-dependent succinic semialdehyde reductase is one of the key enzymes in the brain GABA shunt, and it catalyzes the formation of the neuromodulator $\gamma$-hydroxybutyrate from succinic semi aldehyde. This enzyme was inactivated by diethylpyrocarbonate (DEP) with the second-order rate constant of $1.1{\times}10^3\;M^{-1}min^{-1}$ at pH 7.0, $25^{\circ}C$, showing a concomitant increase in absorbance at 242 nm due to the formation of N-carbethoxyhistidyl derivatives. Complete inactivation of succinic semialdehyde reductase required the modification of five histidyl residues per molecule of enzyme. However, only one residue was calculated to be essential for enzyme activity by a statistical analysis of the residual enzyme activity. The inactivation of the enzyme by DEP was prevented by preincubation of the enzyme with the coenzyme NADPH but not with the substrate succinic semialdehyde. These results suggest that an essential histidyl residue involved in the catalytic activity is located at or near the coenzyme binding site of the brain succinic semialdehyde reductase.