• 한국응용과학기술학회지
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• 제40권6호
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• pp.1298-1308
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• 2023

본 연구는 대학생들이 받는 스트레스와 탈모와의 관련성, 탈모 인식 현황을 파악하고, 유형별 스트레스와 탈모 인식의 상관관계를 분석하는데 목적을 두고 경기도 지역 대학생들을 대상으로 245부의 설문지를 회수하여 SPSS 통계 패키지를 이용하여 분석하였다. 연구 결과 탈모로 인한 가장 큰 문제는 '자신감 상실'로 분석되었고, 특히 진로/취업과 학업에 대한 스트레스가 큰 사람일수록 '자신감 상실'에 대한 문제를 가장 심각하게 생각하고 있는 것으로 분석되고, 탈모 인식에 대한 일반적 특성과 '최근 가장 큰 스트레스' 항목의 교차분석 결과와 유형별 스트레스와 탈모 인식을 구성하는 탈모 현황의 상관관계분석 결과 모든 유형의 스트레스가 대학생 탈모에 영향을 미치는 것으로 분석되었다. 그중 가장 큰 영향을 미치는 스트레스는 진로/취업 스트레스와 학업 스트레스인 것으로 나타났고, 탈모가 생겼을 경우 대인관계나 경제적 문제에 앞서 진로/취업, 학업, 외모를 위해 보다 더 적극적으로 탈모 치료에 임할 의향이 있는 것으로 분석되었다. 따라서 본 연구는 스트레스를 유형별로 분류하고, 탈모 인식에 있어서 탈모 현황, 탈모 관리, 탈모 치료의 3가지 항목으로 구체화하여 실증적 연구 방법을 통해 상관관계를 분석하였다는 점에서 큰 의의가 있다고 판단된다.

• 전기학회논문지
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• 제57권6호
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• pp.924-931
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• 2008

This paper presents a buswise transmission loss allocation algorithm utilizing the transaction strategy. We prove that whatever calculated by any transaction strategy, the total of the allocated transmission losses of each bus, including no-load loss allocation, almost equals the total loss of AC power flow algorithm and the loss is perfectly slackbus-independent. In this paper, the allocated transmission losses of each bus is calculated by the method of integrating loss sensitivities using by the load level parameter ${\lambda}$. The performance of the proposed algorithm is evaluated by the case studies carried out on the WSCC 9-bus and IEEE 14-bus systems.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.2168-2180
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• 2014

In this paper, a generalized power loss algorithm for multilevel neutral-point clamped (NPC) PWM inverters is presented, which is applicable to any level number of multilevel inverters. In the case of three-level inverters, the conduction loss depends on the MI (modulation index) and the PF (power factor), and the switching loss depends on a switching frequency, turn-on and turn-off energy. However, in the higher level of inverters than the three-level, the loss of semiconductor devices cannot be analyzed by conventional methods. The modulation depth should be considered in addition, to find the different conducting devices depending on the MI. In a case study, the power loss analysis for the three- and five-level NPC inverters has been performed with the proposed algorithm. The validity of the proposed algorithm is verified by simulation for the three-and five-level NPC inverters and experiment for three-level NPC inverter.

• 조명전기설비학회논문지
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• 제24권3호
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• pp.33-38
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• 2010

In this paper, the nature of iron loss in electrical steel during alternating field excitation is investigated more precisely. The exact definition of AC iron loss is cleared by accurately measuring the iron loss for conditions of both the sinusoidal magnetic field and sinusoidal magnetic flux density. The results of this approach to iron loss calculations in electrical steel are compared to experimentally-measured losses. In addition, an inverse hysteresis model considering eddy current loss was developed to analyze the iron loss when the input is the voltage source. With this model, the inrush current in the inductor or transformer as well as the iron loss can be calculated.

• 전기학회논문지P
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• 제54권1호
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• pp.15-19
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• 2005

This paper analyzed the power loss characteristics according to winding thickness and winding method of high frequency transformer. Power loss was analyzed by PExprt using FEM tool. The ferrite core model for analysis be used the EE10 type of TDK cop.. Transformer model objected flyback transformer type applied to flyback converter/inverter. Therefore, analysis results of loss were obtained from inner parameters of DC, AC resistance, leakage inductance, copper loss, core loss, and temperature etc.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2001년도 학술대회 논문집
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• pp.169-171
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• 2001

The transport loss of a Bi-2223 tape exposed to external magnetic field was investigated. The results show that the transport loss is independent on voltage lead arrangements in case the magnetization loss is compensated. An serious increase of the transport loss due to external magnetic fields is observed. The loss is described well by dynamic resistance loss in relatively high fields, but another mechanism than the dynamic resistance must be responsible for the increase of the loss in low fields. The transport loss is also dependent strongly on the orientation of the applied field.

• 대한전기학회논문지:전력기술부문A
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• 제50권7호
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• pp.333-339
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• 2001

The transmission networks are not perfect conductors and a percentage of the power generated is therefore lost before it reaches the loads. This network loss effects to the cost of suppling power to consumers, and must be considered if the most efficient dispatch and location of generators and loads is to be achieved. In this paper, we propose an approximate calculation of marginal loss factors to analyze characteristics of transmission loss of KEPCO power system. These static marginal loss factors are approximately calculated based on the KEPCO's expected summer peak load data of year 2000.

• 한국지역사회생활과학회지
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• 제27권3호
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• pp.405-418
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• 2016

This study was conducted to explore the influences of loss experiences and depression on ego-integraty and transcendence of elderly Koreans and to identify gender differences in the relationships among loss experiences, depression, ego-integrity, and transcendence from 146 men and 194 women aged over 60 years in Busan, Gyeong-Nam, and Gyeong-Buk area. The main results were as follows: elderly men reported more loss experiences and transcendence than elderly women. Next, loss experiences influenced ego-integrity and depression mediated the relationship between loss experiences and ego-integrity. Also, ego-integrity had a direct effect on transcendence. Last, depression of elderly men fully mediated the relationship between loss experiences and transcendence. The relationship between loss experiences and ego-integration was partially mediated by depression for elderly women. These results were discussed in terms of gero-education and elderly welfare.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2005년도 학술발표회 논문집
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• pp.102-109
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• 2005

In this study, a prototype model of earthquake loss estimation method will be proposed for the quantitative and qualitative damage evaluation of buried pipeline subjected to Permanent Ground Deformation(PGD) due to liquefaction. With this objective, domestic and foreign status of the arts related with earthquake loss estimation method is summarized at first. Domestic development of computer aided earthquake loss estimation method seems to be difficult for the time being. Thus, referring to HAZUS : Earthquake Loss Estimation Methodology which is developed by FEMA (Federal Emergency Management Agency) and NIBS (National Institute of Building Sciences), earthquake loss estimation procedure of buried pipeline subjected to PGD due to liquefaction are proposed, and then exemplary loss estimation are executed. Considering that there have been no practical earthquake loss estimation method and procedure in Korea, the research accomplishments such as above are considered to be helpful for the substantial development of earthquake loss estimation method of buried pipeline subjected to PGD due to liquefaction.

• 한국물환경학회지
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• 제22권4호
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• pp.619-625
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• 2006

Amount of soil loss is important information for the proper water quality management, In this research, annual average soil loss of the Geum River basin was estimated using RUSLE (Revised Universal Soil Loss Equation) and GIS (Geographic Information System). Input data were manipulated using ArcGIS ver. 8.3. From crop field which constitute 8.2% of the Geum River Basin, annual average soil loss was estimated as 53.6 ton/ha/year. From the rice paddy field which constitutes 20% of the Geum River Basin, soil loss was estimated as 33.5 ton/ha/year, In comparison, forestry area which constitutes 61.8% of the basin discharged 2.8 ton/ha/year, It could be known from this research that appropriate measures should be implemented to prevent excessive soil loss from the agricultural areas.