• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.1245-1249
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• 2017

Recently, unusual transformer failures have been reported in 25kV power systems connected with a VCB and transformer. In this study, performance of the protection system, dielectric strength of the transformers, characteristics of switching surges and resonance phenomena were analysed and assessed. All investigations regarding the insulation breakdown of the transformers were carried out by simulations, laboratory tests, factory tests and on-site measurements in order to thoroughly investigate the root causes. Furthermore, experimental methods for investigating the resonance phenomenon were derived and tests were conducted applying the derived method to recreate the phenomenon in the transformer. It is found that resonance between the transformer and switching surge generated by closing a VCB can initiate the breakdown of internal windings of a transformer.

• 조명전기설비학회논문지
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• 제29권3호
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• pp.81-87
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• 2015

In order to effectively protect electrical and electronic circuits which are extremely susceptible to lightning surges, multi-stage surge protection circuits are required. This paper presents the operational characteristics of the two-stage hybrid surge protection circuit in extra-low voltage DC power lines. The hybrid surge protective device consists of the gas discharge tube, transient voltage suppressor, and series inductor. The response characteristics of the proposed hybrid surge protective device to combination waves were investigated. As a result, the proposed two-stage surge protective device to combination wave provides the tight clamping level of less than 50V. The firing of the gas discharge tube to lightning surges depends on the de-coupling inductance and the rate-of-change of the current flowing through the transient voltage suppressor. The coordination between the upstream and downstream components of the hybrid surge protective device was satisfactorily achieved. The inductance of a de-coupler in surge protective circuits for low-voltage DC power lines, relative to a resistance, is sufficiently effective. The voltage drop and power loss due to the proposed surge protective device are ignored during normal operation of the systems.

• 한국기후변화학회지
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• 제6권3호
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• pp.167-173
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• 2015

The purpose of study is to identify trophic pathways from organic matter to macroinvertebrates in terms of the consumer and to characterize the food webs in an intermittent stream system of the Echi River in Japan. The ${\delta}^{13}C$ values of macroinvertebrates and their potential food sources indicated the scraper (Psephenoides spp., Ecdyonurus levis) and collector-gatherer (Ephemera strigata, Paraleptonphlebia chocolata) feed on periphyton and POM (particulate organic matter) in situ. Davidius lunatus, and Hexatoma spp., which were identified as predators, may feed upon Ephemera strigata and Stenelmis larvae, respectively. At station characterized by seepage water, the ${\delta}^{15}N$ values of Ecdyonurus levis, Lymnaea auricularia, and Rhyacophila nigrocephala larva probably showed relatively lower values according to its diets. Even in homogenous species, the trophic pathways of macroinvertebrates in situ exhibited considerable variation; this reflected the trophic pathways from organic matter to the consumer depending on habitat characteristics in stream.

• Earthquakes and Structures
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• 제23권1호
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• pp.101-113
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• 2022

A new type of fabricated subway station construction technology can effectively solve these problems. For a new type of metro structure form, it is necessary to clarify its mechanical properties, especially the seismic performance. A soil-structure elastoplastic finite element model is established to perform three-dimensional nonlinear dynamic time-history analysis based on the first fabricated station structure-Yuanjiadian station of Changchun Metro Line 2, China. Firstly, the nonlinear seismic response characteristics of the fabricated and cast-in-place subway stations under different seismic wave excitations are compared and analyzed. Then, a comprehensive analysis of several important parameters that may affect the seismic response of fabricated subway stations is given. The results show that the maximum plastic strain, the interlayer deformation, and the internal force of fabricated station structures are smaller than that of cast-in-place structure, which indicates that the fabricated station structure has good deformation coordination capability and mechanical properties. The seismic responses of fabricated stations were mainly affected by the soil-structure stiffness ratio, the soil inertia effect, and earthquake load conditions rarely mentioned in cast-in-place stations. The critical parameters have little effect on the interlayer deformation but significantly affect the joints' opening distance and contact stress, which can be used as the evaluation index of the seismic performance of fabricated station structures. The presented results can better understand the seismic responses and guide the seismic design of the fabricated station.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.841-844
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• 1999

The interference situation from NGSO/FSS network to GSO/FSS network is more complicated than the situation between GSO networks because of the time varying orbital characteristics of NGSO systems. In this paper, the interference characteristics for several types of hand-over strategies are simulated and it is shown that the results should be useful in practical coordination of inter-network interference.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.847-858
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• 2015

Control strategy and corresponding parameters have significant impacts on the overall technical and economic characteristics of composite energy storage systems (CESS). A better control strategy and optimized control parameters can be used to improve the economic and technical characteristics of CESS, and determine the maximum power and stored energy capacity of CESS. A novel coordinated control strategy is proposed considering the coordination of various energy storage systems in CESS. To describe the degree of coordination, a new index, i.e. state of charge coordinated response margin of supercapacitor energy storage system, is presented. Based on the proposed control strategy and index, an optimization model was formulated to minimize the total equivalent cost in a given period for two purposes. The one is to obtain optimal control parameters of an existing CESS, and the other is to obtain the integrated optimal results of control parameters, maximum power and stored energy capacity for CESS in a given period. Case studies indicate that the developed index, control strategy and optimization model can be extensively applied to optimize the economic and technical characteristics of CESS. In addition, impacts of control parameters are discussed in detail.

• 복식
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• 제25권
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• pp.41-62
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• 1995

This research was intended to investigate how risk perception and risk reduction behavior by consumers differ according to different product characteristics of clothing. The responses of 318 female college students living in Seoul and surrounding vicinities were collected and analyzed. Inner wear, blue-jean pants, coat were selected as representing each clothing product characteristics. Frequencies distribution, regression and correlation coefficient were utilized for statistical analysis. Results are as follows. 1. The type of perceived risk and risk reduction behavior differed according to product characteristics of clothing. Physical and performance risk were more highly perceived for the purchase of innerwear. However, for the purchase of jean pants and coat, socio-psycho-logical and economic risk were also perceived highly because the rate of fashion change, social symbolism, and coordination with other clothing items become more important characteristics. To reduce perceived risk, dependency on past purchase experiences and shop-ping were mostly preferred method regardless of product characteristics of clothing. 2. Risk type as determinant variables for predicting overall risk differed according to product characteristics of clothing. But fashionability and usefulness were common determinant risk variables, which identifies typical characteristics of clothing product.

• 디자인학연구
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• 제18권1호
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• pp.167-174
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• 2005

본 연구는 컬러 코디네이션 지원모델과 도구를 개발하여 디자이너의 감성적 직관적 의사결정을 객관적으로 지원하는 것을 목적으로 한다. 이를 위해 본 연구의 선행연구인 '섬유컬러 그루핑 체계에 관한 연구'에서 제안된 컬러 그루핑 체계와 대표 어휘를 바탕으로 본 연구에서는 배색 그룹의 설계를 통해 실용적으로 사용할 수 있는 컬러 코디네이션지원 모델을 제작하였다. 본 연구의 결과를 요약하면 다음과 같다. 첫째, 컬러 그룹을 구성하기 위한 기본 컬러 도출을 위해 $1999{\sim}2003$년까지의 5년간 세계 4대 collection, 2002 F/W 2003 S/S 시즌의 Street 패션, 자 그룹별 대표 브랜드에서 총 687개의 컬러를 수집하였다. 둘째, 687개의 수집된 컬러는 비색 그룹을 위한 추출을 위해 3단계의 과정을 거쳐 총 144색의 컬러로 정리하였다. 셋째, 최종 추출된 컬러는 선행전구에서 제안한 그루핑 체계인 브라이트, 파스텔, 딥, 뉴트럴 그룹으로 분류하였고, 4개의 대그룹은 다시 12개의 소그룹으로 분류하였다. 넷째, 제시된 각 그룹 내의 색깔은 그룹 내에서의 코디네이션은 물론, 타 그룹과도 서로 대치 될 수 있는 크로스 오버코디네이션 개념을 도입하여 커러 코디네이션 체계를 구축하였다. 다섯째, 위와 같이 계통 색조별 4개의 대표 그룹(12개의 소그룹)으로 된 배색 체계를 구성하는 총 144개의 컬러를 섬유패션 디자인 산업의 대표 소재라 할 수 있는 면사에 염색하였다. 또한 글로벌 비즈니스로서의 패션 산업적 특성과 연관 디자인 산업분야와의 호환성을 고려해 시스템을 구성하는 각 색상에는 팬 톤 컬러 기호와 CMYK 값을 명시했다. 여섯째, 완성된 면 소재의 얀(yarn)을 크로스 코디네이션이 용이하도록 디자인된 용기에 포장하여 패션 실무자들이 쉽게 활용 할 수 있는 컬러 코디네이션 시스템을 완성하였다.

• 한국의류산업학회지
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• 제23권6호
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• pp.709-725
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• 2021

The study focused on the design features of Chanel and Fendi, directed by Carl Lagerfeld, creative director of Chanel and Fendi until his recent death. The range of the study was from the 2017 S/S Collection to the 2019 F/W Collection, which collected a total of 767 fashion photographs, including 483 Chanel, 284 Fendi, with tops, bottoms and dresses at VOGUE (https://www.vogue.com). According to the data analysis criteria organized based on prior research and related literature, it was classified in the order of form, color, material, pattern, decoration, fashion image, item and coordination, and content analysis was conducted based on statistical analysis. Overall, the design characteristics of the Chanel collection, directed by Karl Lagerfeld, were rectangle form, tone in tone coloring, combination of identical materials, geometric patterns, and classical images as the main design characteristics of the Chanel collection. The design characteristics shown in the Fendi collection directed by Karl Lagerfeld were rectangle form, tone in tone coloration, hard material combination, abstract pattern, and total coordination. Comparing the design features of Chanel and Fendi, directed by Karl Lagerfeld, is as follows. Chanel and Fendi's designs show a lot of rectangle form, tone-in-tone colors, hard-materials and combination of the same material.

• 한국가정과교육학회지
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• 제27권3호
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• pp.47-61
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• 2015

본 연구는 중학생의 외모관리행동에 따른 바른 인성과 창의적 인성의 차이를 살펴봄으로써 외모관리행동에 따른 바른 인성과 창의적 인성 측면에서 어떤 점들을 고려할 수 있을지에 관한 기초적인 자료를 제공하는데 그 목적이 있다. 따라서 본 연구의 목적을 위해 광주광역시에 소재한 중학교 3학년 600명을 대상으로 2014년 2월 3일부터 2월 14일까지 설문지조사를 실시하였고 544부를 최종분석에 사용하였다. 자료 분석을 위해서 SPSS/PC WIN 19.0 프로그램을 사용하여 기술통계, 요인분석, 신뢰도 분석(Cronbach's ${\alpha}$), 일원분산분석(One-way ANOVA), Duncan-test를 실시하였다. 이와 같은 연구 결과를 살펴볼 때 외모관리행동 중 토털코디네이션 추구행동은 중학생의 관심도가 높고 바른 인성과 창의적 인성과 관련이 깊었다. 바른 인성에서는 기본생활습관과 효도 경애, 창의적 인성에서는 호기심, 사고의 개방성, 위험감수, 과제집착, 심미성에 긍정적인 결과를 보였다. 이러한 점을 고려하여 가정 교과 교육과정에 토털코디네이션 추구행동과 관련된 내용이 보완될 필요성이 있다고 생각된다. 또한, 의생활 영역과 관련된 방과 후 활동 프로그램을 실시하거나 자유학기제를 통한 진로탐색의 기회를 마련하여 토털코디네이션과 관련된 심층적인 교육이 이루어진다면 바른 인성과 창의적 인성에 긍정적인 영향을 미칠 것이라 기대한다.