• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1869-1873
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• 2010

For reliable operation of oil-filled electrical equipment, monitoring and maintenance of insulating oil is essential. Dissolved gas analysis(DGA) is widely used for monitoring faults in high voltage electrical equipment in service. Therefore, oil analysis should be monitored regularly during its service life. KEPCO has investigated thousands of dissolved gas analysis data since 1985, and conducted studies on the relationship of gas in oil analysis and internal inspection results of transformer. As the results, KEPCO revised criteria for transformer diagnosis and has applied it since 2008. Almost of 100 cases of internal inspection results since 2001 have been investigated. This paper presents the correlation of the fault-identifying gases with faults found in actual transformers and how should we approach to internal inspection of transformer by dissolved gas analysis.

• Journal of the Korean Society of Safety
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• v.31 no.1
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• pp.118-125
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• 2016

The purpose of this study is to identify issues for an effective safety culture assessment by conducting a case study of an electronics manufacturing plant in Korea. Cooper's safety culture model was used as the assessment method, and Fleming and Hudson's safety culture maturity models were applied as assessment criteria. The results of the safety culture assessment showed that there needs to be a design optimized for study purposes. For example, the correlation between the questionnaire survey and in-depth interview needs to be analyzed. The result of the behavior monitoring should show the relationships with other dimensions. A safety culture maturity model has to be developed to customize the study factors and questions.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.9
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• pp.1196-1200
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• 2000

First lactation records of 683 Murrah buffaloes maintained at National Dairy Research Institute, Karnal, were used for comparing the sire evaluation for age at first calving, first lactation 305-day or less milk yield and first service period. The sires were evaluated using Simple daughters average, Contemporary comparison, Least-squares and BLUP methods. The BLUP evaluations were obtained under single-, two- and three-trait individual animal models. The results revealed that for taking a decision regarding the method of sire evaluation to be used for selecting sires with high breeding values, criteria of the rank correlation could be misleading and comparison of the selected sires is likely to give a veritable picture. The Best Linear Unbiased Prediction method under multi-trait animal model incorporating first lactation milk yield with first service period as a covariable and age at first calving in the model was found to be more efficient and accurate for sire selection in Murrah buffaloes.

• Science of Emotion and Sensibility
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• v.10 no.4
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• pp.631-637
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• 2007

This research focuses on similarity evaluation of images according to tones of images. Color space of images were converted RGB color space into HSI color space. The information entropy criteria has been taken for evaluating similarity of images for digital library. The similarity was then calculated by combining correlation coefficients and information entropy. Those two values are further analyzed with a relation to human sensibility.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.06b
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• pp.60-66
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• 1998

The horizontal cold chamber pressure die casting produces a variety of net shape, complicate-geometry castings with desired mechanical properties. dimensional tolerance, and surface finish. However, top quality castings can be achieved only when optimal performance of thecold chamber (shot sleeve )and plunger is maintained druing the molten metla injection phase of the process. Unforturately, inreality , shot sleeves deteriorate fast and sometimes fail catastrophically due to incorrect design. These early and unexpected failures of shot sleeves cost die casters money and productiivity. To prevent promature failures of shoe sleeves major faulure mechanisms were investigated. with the aid of analyticla solutions robust design criteria for shot sleeves have been developed. The data directly obtained from failed shot sleeves in the die casting industry for automotive parts, support a strong correlation between design and filures. by applying these design criterial we expected premature faulures of shot sleeves can be avoided in die casting industry.

• The Plant Pathology Journal
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• v.27 no.2
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• pp.110-115
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• 2011

Aggressiveness was studied in seven Plasmopara halstedii (sunflower downy mildew) pathotypes: 100, 300, 304, 314, 704, 710 and 714. Aggressiveness criteria including percentage infection, latent period, sporulation density and reduction of hypocotyl length (dwarfing) were analysed in one sunflower inbred line showing a high level of quantitative resistance. Genetic relationships were detected between the seven pathotypes using 12 EST-derived markers. Pathotypes 100, 300, 304 and 314 were characterized with shorter latent period and higher sporulation density than pathotypes 710, 704 and 714. All pathotypes showed high percentage infection values and caused a large reduction in seedling size except for pathotype 314 involved in dwarfing. Pathotypes 714, 704 and 314 had an intermediary genetic position between the pathotypes 100 and 710. No correlation was detected between aggressiveness traits and EST genotypes.

• Journal of Korean Society of Rural Planning
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• v.3 no.2
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• pp.102-111
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• 1997

For rational agricultural land use planning, it is quite necessary to get hold of land suitability precisely and to make decision on land use patterns accordingly. In the methodological viewpoint, objective and scientific evaluation techniques for land suitability classification should be supported for the systematic land use planning. As one of technical development approaches to rational land use planning, this study tried to frame a land suitability evaluation system for agricultural purposes. Evaluation unit is defined as a tract of land bounded by road, other land units and topographical features. And quantification theory was applied in the determination works of evaluation criteria. The administrative area of Namsa-myon(district), Yongin-si(city), Kyunggi-do(province) was selected for the case study. In order to check the feasibility of the evaluation system developed in the study, field check team, consisting of 2 government officers and 2 representative farmers, carried out evaluation works by observation on 148 sample land units, 10% of total 1,480 ones. Between estimated and observed results, there showed very good relationship of its multiple correlation coefficient, R=0.9467.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.402-405
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• 2006

The diffuser noise of HVAC(heating ventilating and air-conditioning) uses dB(A) or NC as a indoor noise criteria that ASHRAE represents, and there is no specific guide line for application. According to the previous study, there are some problems like that even though the sound level of sound source is same, the NC shows different values, which makes the noise rating confused. This problem is caused by the frequency characteristics of sound source and its sound level. Therefore, appropriate evaluation method should be considered based on the subjective responses. This study aims to analyze the physical parameters appropriate for the evaluation of HVAC diffuser noise. To achieve this, recording of sound sources, calculation of physical parameters and psycho-acoustic experiment were carried out and the results were derived from the correlation analysis between physical parameters and subjective evaluatio

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.5
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• pp.132-144
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• 2001

Iln order to figure out criteria of bentonite for using as impervious material of waste landfill, laboratory experiments were performed to reveal the geotechnical properties of soil-bentonite mixtures such as compaction test, direct shear test, unconfined compression test, triaxial compression test, consolidation test and permeability test. The results of the study are summarized as follows ; 1. Based on the compaction test, optimum moisture content increased with the increase of bentonite content, but maximum dry density decreased. 2. In unconfined compression test, the maximum strength of the soil-bentonite mixtures appeared at 10% bentonite content. The correlation equation between stress($\sigma$) and strain($\varepsilon$) of the soil-bentonite mixtures is given by ; $\sigma=\frac{a\cdot\varepsilon}{\varepsilon^n+b}$ 3. In shear test of the mixtures. the shear strength showed an increasing trend with increase of bentonite content and the maximum shear strength appeared at 10% bentonite content. 4. In consolidation test, the coefficient of compressibility $(a_v)$$(m_v)$$(C_v)$

• Journal of the Korean Society for Library and Information Science
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• v.29
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• pp.305-343
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• 1995

The purposes of this study are to confirm the applicability of the unobtrusive evaluation to Korean libraries, to develop survey forms, check lists and evaluation criteria appropriate for Korean libraries, to analyze the relationship between the test variables and the performance level, to find out the causes of poor service if any, and to propose measures for improving the quality of reference services. The main results of the analyses are as follows : $\cdot$ The accuracy of answers was correlated to appropriateness of search process, way of providing answer, usage of language, approachability and use of second materials in the order named. That is, there was a strong correlation between accuracy and the variables related to librarian's behavior. $\cdot$ There was no statistically significant relationship between accuracy and the environmental aspects of reference department such as number of professional librarians, self-evaluation of reference collection, etc. $\cdot$ The main reasons for failing to give accurate answers were found to be weaknesses in understanding questions. developing search strategy logically and relating the querries to available information sources.