• 제목/요약/키워드: Utility-reduction

검색결과 196건 처리시간 0.02초

의복 착용 동기에 따른 의복 효용 감소에 대한 방응 (Response to Clothing Utility-Reduction according to Clothing-Wearing Motives)

  • 정인희;박상진;권영일
    • 한국의류학회지
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    • 제25권7호
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    • pp.1332-1340
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    • 2001
  • This study was designed (1) to examine the results of previous qualitative research on clothing-wearing motives by quantitative approach, (2) to explore the concept of clothing utility, utility-reduction and discard, and (3) to investigate the impact of clothing-wearing motives on consumer attitudes and consuming-behaviors. Date were collected by questionnaire from 443 collegiate students between August and September of 2000, and 396 questionnaires were analyzed. 3 groups were identified on the basis of clothing-wearing motives and named by extroversion group, introversion group, and least clothing-congnizing group respectively. This supported the qualitative results in part, especially in the direction of motives. Clothing utility-reduction factors were identified as appearance demage, social-psychological damage, and abandonment-causing damage. The 3 groups were responded on utility-reduction differently, thus clothing-wearing motive variable was determined as useful in fashion marketing.

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Reduction of Input Current Harmonics for Three Phase PWM Converter Systems under a Distorted Utility Voltage

  • Park, Nae-Chun;Mok, Hyung-Soo;Kim, Sang-Hoon
    • Journal of Power Electronics
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    • 제10권4호
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    • pp.428-433
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    • 2010
  • This paper proposes a harmonics reduction technique for the input currents of three phase PWM converters. The quality of the phase angle information on the utility voltage connected to the PWM converters affects their control performance. Under a distorted utility voltage, the extracted phase angle based on the synchronous reference frame PLL method is distorted. This causes large harmonics in the input currents of a PWM converter. In this paper, a harmonics reduction method that makes the input currents in the PWM converter sinusoidal even under distorted utility conditions is proposed. By the proposed method, without additional hardware, the THD (Total Harmonic Distortion) of the input currents can be readily limited to below 5% which is the harmonic current requirements of IEEE std. 519. Its validity is verified by simulations and experimental results.

eUCP 11조의 잠재적 하자의 규명과 합리적 개정방안의 모색 (A Study on the Inherent Defects in the eUCP Article 11 & Implication for the Revision)

  • 김기선
    • 무역상무연구
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    • 제35권
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    • pp.41-69
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    • 2007
  • This study analyzes some important implications for the forthcoming revision of eUCP through the methodology of expected utility maximization theory. The overall results are as follows. First, beneficiary with an initial wealth has a risk-averse utility in traditional letter of credit transaction, and he would be more risk-averse in eUCP transaction. Secondly, the beneficiary who has risk-averse utility will pay for the risk premium to reduce the risk of corruption of an electronic record by means of cost of loss reduction activities. Thirdly, the cost of loss reduction activities is represented by a convex cost function, Fourthly, a risk averse beneficiary pursues loss reducing activities to the point where the expected marginal product of loss reduction is less than its marginal cost. Fifthly, a more risk-averse eUCP beneficiary will always select a higher level of loss reduction as long as the effectiveness of loss reduction is certain. Sixthly, when the effectiveness of loss reduction is uncertain, the more risk-averse eUCP beneficiary does not necessarily choose a higher level of loss reducing activities. Finally, it would be more reasonable that eUCP Article 11 should protect eUCP beneficiary who pursues a higher level of loss reducing activities.

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한국형기동헬기 진동저감장치 (Vibration Reduction Devices for Korean Utility Helicopter)

  • 정세운;곽동일;김세희;최종호;심대성
    • 한국항공우주학회지
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    • 제41권12호
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    • pp.987-993
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    • 2013
  • 한국형기동헬기(KUH)는 국내 최초로 개발된 헬기로서, 2010년 3월 초도 비행을 시작으로 2012년 6월 체계 개발을 성공적으로 종료하였다. 비행시험 단계에서 다양한 진동문제가 발생하였으며 이를 제어하기 위해 적절한 진동저감장치를 설계하고 적용하였다. 한국형 기동헬기의 주요 진동 성분인 $4{\Omega}$ 주파수 진동 저감을 위해 주로터 블레이드, 주기어박스 지지부, 조종실, 승객실 그리고 조종좌석에 진동저감장치를 적용하였다. 또한, 테일-쉐이크 진동 제어를 위해 돔페어링을 적용하였다. 본 논문에서는 한국형 기동헬기에 적용된 진동저감장치들의 해석 및 설계 기법과 비행시험 결과를 제시한다.

Development of safety-Based Guidelines for Cost-Effective Utility Pole Treatment along Highway Rights-of-Way

  • 김정현
    • 대한교통학회:학술대회논문집
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    • 대한교통학회 1997년도 제32회 학술발표회
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    • pp.33-69
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    • 1997
  • This study was conducted to develop a methodology to predict utility pole accident rates and to evaluate cost-effectiveness for safety improvement for utility pole accidents. The utility pole accident rate prediction model was based on the encroachment rate approach introduced in the Transportation Research Board Special Report 214. The utility pole accident rate on a section of highway depends on the roadside encroachment rate and the lateral extent of encroachment. The encroachment rate is influenced by the horizontal and vertical alignment of the highway as well as traffic volume and mean speed. The lateral extent of encroachment is affected by the horizontal and vertical alignment, the mean speed and the roadside slope. An analytical method to generate the probability distribution function for the lateral extent of encroachment was developed for six kinds of encroachment types by the horizontal alignment and encroachment direction. The encroachment rate was calibrated with the information on highway and roadside conditions and the utility pole accident records collected on the sections of 55mph speed limit of the State Trunk Highway 12 in Wisconsin. The encroachment rate on a tangent segment was calibrated as a function of traffic volume with the actual average utility pole accident rates by traffic volume strategies. The adjustment factors for horizontal and vertical alignment were then derived by comparing the actual average utility pole accident rates to the estimations from the model calibrated for tangent and level sections. A computerized benefit-cost analysis procedure was then developed as a means of evaluating alternative countermeasures. The program calculates the benefit-cost ratio and the percent of reduction of utility pole accidents resulting from the implementation of a safety improvement. This program can be used to develop safety improvement: alternatives for utility pole accidents when a predetermined performance level is specified.

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Development of safety-Based Guidelines for Cost-Effective Utility Pole Treatment along Highway Rights-of-way

  • 김정현
    • 대한교통학회:학술대회논문집
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    • 대한교통학회 1997년도 제32회 학술발표회
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    • pp.35-72
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    • 1997
  • This study was conducted to develop a methodology to predict utility pole accident rates and to evaluate cost-effectiveness for safety improvement for utility pole accidents. The utility pole accident rate prediction model was based on the encroachment rate approach introduced in the Transportation Research Board special Report 214. The utility pole accident rate on a section of highway depends on the roadside encroachment rate and the lateral extent of encroachment. The encroachment rate is influenced by the horizontal and vertical alignment of the highway as well as traffic volume and mean speed. The lateral extent of encroachment is affected by the horizontal and vertical alignment, the mean speed and the roadside slope. An analytical method to generate the probability distribution function for the lateral extent of encroachment was developed for six kinds of encroachment types by the horizontal alignment and encroachment direction. The encroachment rate was calibrated with the information on highway and roadside conditions and the utility pole accident records collected on the sections of 55mph speed limit of the State Trunk Highway 12 in Wisconsin. The encroachment rate on tangent segment was calibrated as a function of traffic volume with the actual average utility pole accident rates by traffic volume strategies. The adjustment factors for horizontal and vertical alignment were when derived by comparing the actual average utility pole accident rates to the estimations from the model calibrated for tangent and level sections. A computerized benefit-cost analysis procedure was then developed as a means of evaluating alternative countermeasures. The program calculates the benefit-cost ratio and the percent of reduction of utility pole accidents resulting from the implementation of a safety improvement. This program can be used to develop safety improvement alternatives for utility pole accidents when a predetermined performance level is specified.

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교통안전진단 개선방안들의 우선순위 산정 연구 (A Study on Practical Method of Utility Curve for Deciding Priority Order of the Improvements in Traffic Safety Audit)

  • 최지혜;강순양;홍지연;임준범
    • 한국안전학회지
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    • 제31권3호
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    • pp.143-155
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    • 2016
  • Recently, a massive loss of life and property is occurring in Korea due to traffic accidents, with the rapid increase in cars. For improvement of traffic safety, the Korea Transportation Safety Authority intensively analyzes accident data in local governments with low traffic safety index, performs a field investigation to extract problems and offers local governments improvements for problems, by conducting the 'Special Survey of Actual Conditions of Traffic Safety' each year, starting 2008. But local governments cannot strongly push forward the improvement projects due to the limited budget and the uncertainty of the improvement plan effects. Therefore, this study suggested a model which applied the Utility concept to the AHP theory, in order to efficiently decide a priority of the improvement plans in accident black spots in consideration of the limited budget of local governments. The number of accidents in each spot for improvement and accident severity, traffic volume, pedestrian volume, the improvement project cost and the accident reduction effect were chosen as evaluation factors for deciding a priority, and data about the improvement plan costs and the accident reduction effects, traffic accidents and traffic volume in the spots to undergo the special research on the real condition of traffic accident in the past were collected from the existing studies. Then, regression analysis was carried out and the Utility Curve of each evaluation factor was computed. Based on the AHP analysis findings, this study devised a priority decision method which calculated the weight and the utility function of each evaluation factor and compared the total utility values. The AHP analysis findings showed that among the evaluation factors, accident severity had the biggest importance and it was followed by the improvement plan cost, the number of accidents, the improvement effect, traffic volume and pedestrian volume. The calculated utility function shows a rise in utility, as the variables of the 5 evaluation factors; the number of accidents, accident severity, the improvement plan effect, traffic volume and pedestrian volume increase and a fall in utility, as the variables of the improvement plan cost increase, since the improvement plan cost is included in the budget spent by a local government.

전력회사의 스타콘 투입시 과도 전압 상승과 고조파 분석에 관한 연구 (A Study on the Analysis of Transient Overvoltages and Harmonics due to Utility STATCON Switching)

  • 김경철;서범관;송영주;이일무
    • 조명전기설비학회논문지
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    • 제17권5호
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    • pp.51-59
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    • 2003
  • 전력회사와 수용가들은 유도성 부하에 무효전력을 공급하여 역률(수용가)이나 전압(전력회사)을 조절하기 위해 커패시터 뱅크(전력회사는 스타콘이라 함)를 설치 운영하고 있다. 본 논문에서는 전력회사의 스타콘 투입시 발생되는 과도 전압 상승과 고조파를 분석하고자 한다. 과도 전압과 고조파를 저감시키는 간단한 수단중의 하나는 수용가의 커패시터 뱅크를 전력회사의 스타콘을 투입한 후에 과도상태가 지난뒤에 투입하는 방법이다. EDSA프로그램으로 컴퓨터 시뮬레이션을 수행하여 수용가에서의 과도 전압 상승과 고조파 저감 효과를 검증 하였다. 그리고 수용가에서 발생하는 고조파를 잘 알려진 국제 고조파 관리 기준인 IEEE 519와 IEC 1000으로 비교해 보았다.

사출 성형품의 휨과 웰드라인을 최적화하기 위한 자동 금형설계 방법 (Automatic Mold Design Methodology to Optimize Warpage and Weld Line in Injection Molded Parts)

  • 박종천
    • 소성∙가공
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    • 제9권5호
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    • pp.512-525
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    • 2000
  • Designers are frequently faced with multiple quality issues in injection molded parts. These issues are usually In conflict with each other, and thus tradeoff needs to be made to reach a final compromised solutions. The objective of this study is to develop an automated injection molding design methodology, whereby part defects such as warpage and weld line are optimized. The features of the proposed methodology are as follows: first, Utility Function approach is applied to transform the original multiple objective problem into single objective problem. Second is an implementation of a direct search-based Injection molding optimization procedure with automated consideration of process variation. The Space Reduction Method based on Taguchi's DOE(Design Of Experiment) is used as a general optimization tool in this study. The computational experimental verification of the methodology was partially carried out for a can model of Cavallero Plastics Incorporation, U. S. A. Applied to production, this study will be of immense value to companies in reducing the product development time and enhancing the product quality.

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모듈러 건축용 기계설비 시스템 현황 및 개발에 관한 연구 (Present Condition and Development of Mechanical Utility System for Modular Construction)

  • 이재수;최준석
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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    • pp.19-20
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    • 2016
  • Domestic construction industry has experienced many difficulties as it has been on a downward. It's a way that active modular structure market to solve this problem. However, as Modular structure technical standard in Korea is in the early stages, our modular factory maufactured rate is almost 40% lower than overseas. Besides, there is less design diversity so it just applies for a few buildings like low-rise building and general group barrackes. To deal with these problems, it is essential to modulating the equipment which can improve the production rate. This will help to ensure the quality, shortening of the construction period, the reduction of labor costs. We have defined the name of segmented by each installation location of the equipment to modulating equipment. And it was examined the suitability of the modulating of the location-specific utility system. The results of the analysis are discussed on the page.

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