• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1708-1717
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• 2023

The grade analysis of lead-zinc ore is the basis for the optimal development and utilization of deposits. In this study, a method combining Prompt Gamma Neutron Activation Analysis (PGNAA) technology and machine learning is proposed for lead-zinc mine borehole logging, which can identify lead-zinc ores of different grades and gangue in the formation, providing real-time grade information qualitatively and semi-quantitatively. Firstly, Monte Carlo simulation is used to obtain a gamma-ray spectrum data set for training and testing machine learning classification algorithms. These spectra are broadened, normalized and separated into inelastic scattering and capture spectra, and then used to fit different classifier models. When the comprehensive grade boundary of high- and low-grade ores is set to 5%, the evaluation metrics calculated by the 5-fold cross-validation show that the SVM (Support Vector Machine), KNN (K-Nearest Neighbor), GNB (Gaussian Naive Bayes) and RF (Random Forest) models can effectively distinguish lead-zinc ore from gangue. At the same time, the GNB model has achieved the optimal accuracy of 91.45% when identifying high- and low-grade ores, and the F₁ score for both types of ores is greater than 0.9.

• Journal of the Korea Fashion and Costume Design Association
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• v.26 no.1
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• pp.99-109
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• 2024

This study focused on analyzing the difference in the impact of non-financial performance, specifically ESG (Environmental, Social, and Governance) activity grade level, on management performance and corporate value among the 25 fashion companies listed on the Korea Exchange that completed their ESG evaluation in 2022. The companies were categorized into three levels based on their ESG evaluations: ESG Integrated Grade (ESG-T), ESG-E (Environmental), ESG-S (Social), and ESG-G (Governance). The study then empirically analyzed how these levels affected management performance and corporate value. The empirical analysis revealed significant differences in the impact on management performance and corporate value depending on the ESG activity grade level. Companies with higher ESG grades exhibited better management performance and higher corporate values across all ESG sub-variables (ESG-T, ESG-E, ESG-S, ESG-G) compared to those with lower grades. This finding demonstrates the influence of ESG activity grade levels on improving management performance and enhancing corporate value in fashion companies. The results of this research provide meaningful insights into the direction of sustainable management through ESG activities in fashion companies.

• Korean Journal of Materials Research
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• v.14 no.1
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• pp.78-82
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• 2004

In this study, the degree of creep damages on the weldment accelerated creep degradation was nondestructively evaluated by replica method. The frequency of creep cavities occurrence has been observed highly at the intercritical HAZ. The life fraction of weldment damaged by creep has shown from 0.25(damage grade: 2) to 0.75(damage grade: 4) when it reptured. The degree of creep damages is considered to be evaluated by the metallographic replica method which is one of nondestructive evaluation methods.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.3
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• pp.119-123
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• 2013

Most of the world's solar cells in photovoltaic industry are currently fabricated using crystalline silicon. Czochralski-grown silicon crystals are more expensive than multicrystalline silicon crystals. The future of solar-grade Czochralski-grown silicon crystals crucially depends on whether it is usable for the mass-production of high-efficiency solar cells or not. It is generally believed that the main obstacle for making solar-grade Czochralski-grown silicon crystals a perfect high-efficiency solar cell material is presently light-induced degradation problem. In this work, the substitution of boron with gallium in p-type silicon single crystal is studied as an alternative to reduce the extent of lifetime degradation. The diamond-wire sawing technology is employed to slice the silicon ingot. In this paper, the quality of the diamond wire-sawn gallium-doped silicon wafers is studied from the chemical, electrical and structural points of view. It is found that the characteristic of gallium-doped silicon wafers including texturing behavior and surface metallic impurities are same as that of conventional boron-doped Czochralski crystals.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.2
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• pp.264-277
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• 1995

is designed to study the college women's desirable clothing behavior in campus, and to find out the difference in person perception according to appropriate or inappropriate clothing. Detailed object is to find out the following differences according to appropriate and inappropriate clothing in campus: 1) formation of impression 2) inference of value. Addi\ulcorner tionally the difference in person perception according to major, grade and preference group are studied. For data collection, 460 college women who are attending Ewha Woman's University are included, and convenience sampling method is used. Frequency, percentage, mean, factor analysis, t-test, ANDV A. duncan test, correspondent analysis are used for data analysis. The result are as follows: 1) Wearer's impression is devided into four factors: appearence evaluation, personality evaluation, ability and activity. 2) There are significant differences in impression formation and value inference according to situational appropriateness. 3) There are significant differences in person perception according to major, grade and preference group.

• Journal of Korean Home Economics Education Association
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• v.9 no.2
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• pp.17-30
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• 1997

Purpose of this study is to analyze the validity of textbook content on practical arts for the 6th curriculum, to grasp the content problems and to propose the strategy of reformation to be satisfied with consumer better than supplier. The data collected from 196 elemantary school teachers who lived in Gyungsang-namdo and analized by SPSS/PC(sup)+ package program. The statistical methods used for analysis were frequency, descriptives, validity, t-test, oneway ANOVA. The major findings can be summarised as follows： 1. The textbooks on practical arts for 3rd, 4th, 5th and 6th grades showed unbalanced division for picture, figure, table unite and evaluation type of all units doesn’t show diversity. 2. The validity of textbook contents on practical arts was found to be the highest for 3rd grade textbook and the lowest for 6th grade one. Among the validity of the evaluation items,‘differentiation with other subject’and ‘usefulness of living’showed high scores, wheres ‘fitness of child level’marked lowest score. 3. There was no significant difference Among the validity contents of teachers based on socio-demographic variables.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.98-103
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• 2003

Based on ASME probabilistic risk assessment (PRA) and NEI PRA peer review guidance, we evaluate a human reliability analysis (HRA) in probabilistic safety assessment (PSA) for Korea standard nuclear power plants, Ulchin Unit 3&4, to improve it performed at under design. The HRA for Ulchin Unit 3&4 is assessed as higher than Grade I based on ASME PRA standard and as higher than Grade 2 based on NEI PRA peer review guidance. The major items to be improved identified through the evaluation process are the documentation, the systematic human reliability analysis, the participitation of operators in the works and review of HRA. We suggest the guidance on the identification and qualitative screening analysis for pre-accident human errors and solve some items to be improved using the suggested guidance.

• The Mathematical Education
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• v.42 no.5
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• pp.673-682
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• 2003

In this paper, we studied how to organize and develop a web based diagnostic-formative evaluation system. We investigated the interest of students about the system and analyze their scores after we applied this system to 10-th grade students for 10 months.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.06a
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• pp.33-42
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• 2003

Since the cut slope has been big concern due to frequent failures, the government decided to include cut slopes in the“Act for Safety Control of Public Structures”. Based on the Act, the cut slope whose height is over 50m and length is over 200m should be inspected on the regular basis. According to the Act, KISTEC developed the objective evaluation method for the condition of cut slope. The evaluation method is divided into two categories: evaluation for damaged condition and evaluation for failure affecting factor. Based on the evaluation results, the cut slope is graded from A to E. In this study, the process to evaluate the cut slope condition and the evaluation criteria to divide the grade of cut slope are introduced.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1233-1238
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• 2013

The course evaluation is used in faculty evaluation model even the grade of course evaluation has a big gap in absolute value with the characteristics of subjects. It is important to obtain the reliability of course evaluation because the result of course evaluation is fed to instructor to assure the quality of instruction. The purpose of this paper are to analyze the relation of attendance rate and course evaluation to improve the reliability of course evaluation.