• Title/Summary/Keyword: on-line analysis

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Electric Power Characteristics of a SFCL based on Turn-ratio of 3-Phase Transformer (3상 변압기의 권수비에 따른 초전도 한류기의 전력특성)

  • Jeong, In-Sung;Choi, Hyo-Sang;Jung, Byung-Ik
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.3
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    • pp.414-417
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    • 2014
  • At present, the demand for electric power increases, the electric power system is complicated. The size of the line-to-ground fault and the line-to-line fault occurred with complication of electric power system continue to increase, therefore several issues are raised. To address these issues effectively, the superconducting fault current limiter (SFCL) has been proposed, this study is ongoing. In this paper, we applied the SFCL in three-phase transformer and comparative analysis of the electric power burden to the SFCL. The superconductor is combined to the third winding of transformers in connection structure. In case of a third line-to-line fault, we did comparative analysis of the electric power burden to the SFCL based on the turn ratio of transformer third winding. In this case, we could confirm as the third turn ratio increased, electric power impressed to the superconducting element increased.

Analysis of Symmetric Coupled Line with New Crossbar Embedded on Si-based Lossy Structure using the FDTD Method (실리콘에 기초한 새로운 크로스바 구조의 손실있는 대칭 결합선로에 대한 유한차분법을 이용한 해석)

  • Kim, Yoonsuk
    • Journal of the Korea Institute of Military Science and Technology
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    • v.4 no.2
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    • pp.122-129
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    • 2001
  • A characterization procedure for analyzing symmetric coupled MIS(Metal-Insulator-Semiconductor) transmission line is used the same procedure as a general single layer symmetric coupled line with perfect dielectric substrate from the extraction of the characteristic impedance and propagation constant for even- and odd-mode. In this paper, an analysis for a new substrate shielding symmetric coupled MIS structure consisting of grounded crossbar at the interface between Si and SiO2 layer using the Finite- Difference Time-Domain(FDTD) method is presented. In order to reduce the substrate effects on the transmission line characteristics, a shielding structure consisting of grounded crossbar lines over time-domain signal has been examined. Symmetric coupled MIS transmission line parameters for even- and odd-mode are investigated as the functions of frequency, and the extracted distributed frequency- dependent transmission line parameters and corresponding equivalent circuit parameters as well as quality factor for the new MIS crossbar embedded structure are also presented. It is shown that the quality factor of the symmetric coupled transmission line can be improved without significant change in the characteristic impedance and effective dielectric constant.

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On-line PD Monitoring Using UHF Technique (UHF 가술을 이용한 온라인 PD 모니터링)

  • Choi, Yong-Sung;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.04c
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    • pp.115-118
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    • 2008
  • A field-oriented UHF system for on-line PD monitoring of transformers. is designed, which has been installed inside the oil tank of a transformer by two ways: on-line installing mode through the oil-valve and pre-installing mode through the man hole/hand hole cover. This system has successfully captured long intermittent discharge signals that hadn't been detected through conventional techniques, and solved the problem successfully. The results demonstrate that UHF technique has great advantages for on-line PD monitoring of transformers. By adopting the peak detection technique, it becomes easy and effective for the transplantation of the phase-resolved pattern recognition technique from conventional method to UHF method, and then to realize continuous on-line monitoring, source characterization and trending analysis.

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Development of an On-line Consultant Training System for Consulting-Supervision (컨설팅장학을 위한 온라인 컨설턴트 교육 시스템 개발)

  • Hong, Gak-Pyo;Rha, MinJu;Jung, Jae-Hun;Kim, Mihye;Yoo, Kwan-Hee
    • The Journal of the Korea Contents Association
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    • v.14 no.7
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    • pp.18-28
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    • 2014
  • With the reformation of organization and function of local office of education in 2010, consulting-supervision is introduced to schools as a system for education reform to improve the quality of school education. However, a dedicated on-line portal system that can provide integrated management on the functionalities of consulting-supervision has not been implemented yet. To successfully operate consulting-supervision in schools, it is also needed to provide an on-line consultant education system, that can support teachers to train themselves as a supervision-consultant. In this paper, we introduce an on-line consultant training system that provides various learning activity tools for consultant training based on Learning Activity Management System(LAMS) and Action Learning. The system consists of Management stage, Analysis stage, Solution stage, and Action stage for the empowerment of consultants' expertises, and is named as MASA. Brain-writing, SWOT(Strengths, Weaknesses, Opportunities, and Threads) analysis, 5Whys, decision grid, PMI(Plus, Minus, Interesting), and black chart techniques were developed in MASA as learning activity tools for consultant training.

A Study on the Formative Characteristic and the Components of Visual Evaluation of the Bolero (볼레로의 조형적 특성과 시각적 평가의 구성요인)

  • Kim, Jeong-Mee;Lee, Jung-Soon
    • Fashion & Textile Research Journal
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    • v.8 no.6
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    • pp.679-686
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    • 2006
  • The purposes of this study are to look into the formative characteristics of the bolero and to evaluate the visual effects and images according to changes in the line and length of the connecting lines of the neck, center front, and hem lines from analyzing the bolero style shown in 2005 S/S domestic fashion. Theoretical examination of the bolero was made philologically with reference books, theses and some articles. And the bolero style shown in 2005 S/S domestic fashion was analyzed with pictures from a fashion magazine "Ceci" and a fashion website 'Interfashion Planning" from Feb. to Aug. of 2005. As a result, the basic lines of the bolero are classified into three different categories according to the connecting lines of the neck, center front line, and hem line. We altered the length of the bolero in three categories with the changes in the waistline-5 cm, 8 cm, and 11 cm. For the visual evaluation, 9 stimuli were placed in mannequins, and were estimated by the experts in the fashion design. For the visual evaluation according to changes in the line and length of the bolero, we used 12 pairs of items to find the visual effects, and 13 pairs of adjectives to measure the visual images. The stimuli and adjectives were randomly given to the evaluators and were evaluated by the 7-Point Likert Type Scale. Data we got from this experiment was analyzed statistically by using the SPSS 12.0 and practiced the Factor Analysis and Correlation Analysis. In the current women's garments, the bolero is a new fashion item which combines with jackets or cardigans. Usually the bolero jacket is made out of a cotton, denim, leather or fur, and the bolero cardigan usually used knitted materials. The design could be very varied depending on the roundness of the center front line, and hem line. According to the result of factor analysis of the visual effects of the Bolero, four factors were identified the whole silhouette, neck line, breasts and shoulders. According to the result of factor analysis of the visual image of the Bolero, three factors were identified maturity, tenderness, neatness.

Electromagnetic Environment of Transmission Line Based on Full Parameter Online Estimation

  • Sun, Zidan;Zhou, Xiaofeng;Liang, Likai;Mo, Yang
    • Journal of Information Processing Systems
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    • v.16 no.2
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    • pp.394-405
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    • 2020
  • The parameters of transmission lines have an influence on the electromagnetic environment surrounding the line. This paper proposes a method based on phasor measurement unit (PMU) and supervisory control and data acquisition (SCADA) to achieve online estimation of transmission line full parameters, such as resistance, reactance and susceptance. The proposed full parameter estimation method is compared with the traditional method of estimating resistance independently based on SCADA system. Then, the electromagnetic environment is analyzed based on the different parameter estimation methods. The example results illustrate that online estimation of transmission line full parameters is more accurate in the analysis of electromagnetic environment, which further confirms its necessity and significance in engineering application.

The Study on the Effect of Waiting Line on Consumers' Perceived Quality and Emotional State

  • Li, Nan;Song, Jae-Do
    • Asia Marketing Journal
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    • v.21 no.2
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    • pp.21-49
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    • 2019
  • This study examines a model which simultaneously contains two paths between waiting line and purchase intention: one tested the positive effect of waiting line through consumers' perceived quality, whereas another one go through consumers' emotional state to test the negative effect of waiting line on purchase intention. To further understand perceived quality, the study divided perceived quality into perceived product quality and perceived service quality. The study used restaurants in the experiment. Results indicated that although long waits in line will directly increase both consumers' product quality perception and negative emotions, the total indirect effects on purchase intention are still significantly positive. For consumers' perceived service quality, long waiting situations have no such effect on it. Significant results from a moderation analysis also shown that consumers in low-level knowledge settings are more influenced by waiting lines than those in high-level knowledge settings when they make the product's quality-related judgment. However, the level of consumer knowledge does not moderate the relationship between waiting lines and service quality.

A Study on Reclosing Decision on 154kV Combined Transmission Lines (154kV 혼합송전선로 재폐로 결정에 관한 연구)

  • Jung, Chae-Kyun;Park, Hung-Sok;Kang, Ji-Won;Lee, Jong-Beom
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.10
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    • pp.1761-1769
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    • 2010
  • This paper describes switching surge analysis on reclosing decision in 154kV combined transmission line with power cables. Reclosing should be operated in combined transmission line based on the technical evaluation because of insulation problem of power cable section. If the surge strikes on power cable, the breakdown can occur at week point of cable insulation. Therefore the detailed analysis is required by considering several conditions such as length ratio of power cable, arrester, fault resistance, charging rate and grounding resistance, etc.. In addition, sheath voltage on IJ(Insulated Joint) is analyzed to confirm the protective level. Simulation is performed by EMTP/ATP. Analysis results show that reclosing can be operated without any special problem by the single line-to-ground fault with fault resistance of $1\Omega$ to $50\Omega$ occurred at the overhead transmission section in 154kV combined transmission lines and trap charge of 100% and 110%.

A Study on Determination of Ranking for Railroad Line's Improvement in Seoul using Fuzzy Theory (Fuzzy모형을 이용한 시가지 내 철도선로 정비 우선순위 결정에 관한 연구)

  • 손기복;김경철
    • Proceedings of the KSR Conference
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    • 1998.05a
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    • pp.184-193
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    • 1998
  • The existence of railroad line gives many influences in various kinds of aspects. To minimize negative influences is necessary to line's improvement, but appropriate methodology doesn't show until now. In this study, Fuzzy Integration Method(FIM) are employed in an effort to give ranking for railroad line's improvement in Seoul. The FIM is designed to generalize a various influences, appeared on account of existence of railroad line. Empirical analysis is performed for railroad line in distance of 83.5㎞ in Seoul. The total lines are divided in 51 sections, and there are selected a 11 evaluation index to reflect influences. Through a questionnaire survey about residents, operator and administrator, important degree of evaluation items are decided, reveal ins the interests of related groups. Then, evaluation values are calculated wi th practical survey results about each sections. The results of evaluation reveal that the higher ranking of improvement from FIM concentrates the Kyeng-Ul Line and Kyeng-Won line because these lines appear a many public discontents and negative influences such as noise and demolition of living environment.

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Antitumoral Compound, MCS-202, an Effector on Proliferation and Morphology of Human Breast Tumor Cell Line, MCF-7 (인체유암세포주 MCF-7의 형태변화와 증식에 영향을 주는 항암활성물질, MCS-202)

  • 이성우;김세은;김항섭;김환묵;이정준;김영호
    • Microbiology and Biotechnology Letters
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    • v.21 no.6
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    • pp.594-599
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    • 1993
  • In the course of screening for microbial metabolites employing human cancer cell line, we identified a mycelial extract of Streptomyces sp. 1365, which are effective on growth inhibition and morphological change of MCF-7, human breasr cancer cell line. By repeased column chromatography and recrystallization process, yellow needle crystals were obtained as an active compound and identified as resistomycin by spectral analysis.

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