• 제목/요약/키워드: Phase Criteria

검색결과 539건 처리시간 0.03초

상시 계측결과를 이용한 경부고속철도 교량의 동적거동 분석 (A analysis on dyanmic movements of Bridge status using High Rail monitoring systems)

  • 정재민;한상철;최일윤;이준석;서형렬
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 추계학술대회 논문집
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    • pp.934-939
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    • 2004
  • The Korea high-speed rail, based on the French design. It also implements new concept to increase the strength of bridge deck by adding an impact factor (dynamic intensity factor) in static load. In order to assure the dynamic stability, SYSTRA and Jeseph Penzien, a professor in CEC (the US) conducted a dynamic stability review on design phase. Analyzing the review results, they developed design criteria for dynamic behavior. This study deal with operating PSC box GIRDER equipped with measurement equipment or measured data of Seoul $\∼$ Taejeon, P.S.C BOX GIRDER bridge and steel comsition bridge equipped with measurement equipment based on structual knowledge about configuration of measuring sensor, response analysis of structure when train runs was performed by using measured data of PSC box girder to directly compare with design criteria. moreover, the dynamic stability with comparison of high-speed rail construction criteria was reviewed and analyzed based on historical records.

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Analysis and Design of LCL Filter with Passive Damping Circuits for Three-phase Grid-connected Inverters

  • Ahn, Hyo Min;Oh, Chang-Yeol;Sung, Won-Yong;Ahn, Jung-Hoon;Lee, Byoung Kuk
    • Journal of Electrical Engineering and Technology
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    • 제12권1호
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    • pp.217-224
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    • 2017
  • The analysis and design process of the LCL filter with passive damping circuits for three-phase grid-connected inverter are presented based on the generalized model of LCL filter. Several types of the passive damping circuits in previous studies could be compared and analyzed by using the generalized model considering various design criteria of passive damping circuits. According to the analysis in this paper, a reasonable configuration of passive damping circuits for three-phase grid-connected inverters is proposed. The validity of the proposed design process is verified by informative simulation and experimental results.

Analysis of MOSFET Failure Modes in Bi-directional Phase-Shift Full-Bridge Converters

  • Oh, Chang-Yeol;Sung, Won-Yong;Kim, Yun-Sung;Lee, Byoung-Kuk
    • Journal of Electrical Engineering and Technology
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    • 제10권4호
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    • pp.1692-1699
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    • 2015
  • This paper presents an analysis of the mechanism of failure modes in bi-directional phase-shift full-bridge converters, composed of MOSFET, based on the circuit operation and parasitic parameters of MOSFET. In addition, the relation between circuit operation and parameters is suggested through an experimental comparison. From this relation, the suitable ranges of parameters for stable performance are analyzed. The design criteria of the bi-directional phase-shift full-bridge converter are presented and evaluated from the experimental verification.

전자조달을 위한 공급자 선택 지원 시스템의 개발 (A Decision Support System for Supplier Selection in B2B E-procurement)

  • 하성호;남미성
    • 경영과학
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    • 제21권1호
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    • pp.113-129
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    • 2004
  • Nowadays many enterprises build e-procurement systems. An e-procurement is a Web-based procurement process and its functionalities are considered important in the B2B e-commerce. Buyers should select competent suppliers for a successful e-procurement. Therefore, this study proposes a method using the analytic hierarchy process(AHP) for building a Web-based supplier selection system. In detail, the purpose of this study is (1) to review methods previously used when buyers selecting suppliers and to extract important selection criteria: (2) to explain extended AHP method adopted by this study among supplier selection methods: (3) to describe the supplier selection steps using extended AHP : and (4) to propose a decision support system embedding the methodology described above. The proposed system comprises of three phase: first phase is to evaluate suppliers on enterprise level: second phase to evaluate them on each transaction level: third phase to post-evaluate them.

Design Method for the LCL Filters of Three-phase Voltage Source PWM Rectifiers

  • Guo, Xizheng;You, Xiaojie;Li, Xinran;Hao, Ruixiang;Wang, Dewei
    • Journal of Power Electronics
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    • 제12권4호
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    • pp.559-566
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    • 2012
  • A new design method for the LCL filters of three-phase voltage source PWM rectifiers is presented in this paper. Based on the single-phase harmonic equivalent model, the harmonic voltage of the rectifier side is calculated to design the LCL filter parameters by an iterative algorithm, in which the resonance frequency $f_{res}$ and the ratio r between the grid-side inductance and the rectifier-side inductance are selected as known constants. The design criteria and process are introduced and the influence on the design result by the value of the resonance frequency $f_{res}$, ratio r is analyzed. Finally an example (600V, 500kW) is tested by simulation and experiment to verify the validity of the new design method.

PCM의 잠열측정을 위한 T-history법에 대한 고찰 (Consideration on the T-history Method for Measuring Heat of Fusion of Phase Change Materials)

  • 박창현;최주환;홍희기
    • 설비공학논문집
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    • 제13권12호
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    • pp.1223-1229
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    • 2001
  • Though conventional calorimetry methods such as differential scanning calorimetry (DSC) and differential thermal analysis (DTA) are used generally in measuring heat of fusion, T-history method has the advantages of a simple experimental apparatus and no requirements of sampling process, which is particularly useful for measuring thermal properties of inhomogeneous phase change materials (PCMs) in sealed tubes. However, random criteria (a degree of supercooling) used in selecting the range of latent heat release and neglecting sensible heat during the phase change process can cause significant errors in determining the heat of fusion. In the present study, it was shown that a 40% discrepancy exists between the original T-history and the present methods when analyzing the same experimental data. As a result, a reasonable modification to the original T-history method is proposed.

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시공단계의 사고손실 비용 기반 건설안전 위험성 평가 방안 (Construction Safety Risk Assessment Method Based on Accident Loss Cost in the Construction Phase)

  • 이재현;정재욱;정재민
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2023년도 봄 학술논문 발표대회
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    • pp.407-408
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    • 2023
  • This article proposes a method to assess construction safety risk during the construction phase based on accident loss costs. Risk assessments for hazardous construction work are required by law, but they lack quantitative criteria. To address this, a survey estimated loss costs due to fatalities in the construction industry, finding labor loss cost and delay reimbursement cost to be the largest factors. The proposed method uses algorithm to calculate expected accidents and risk levels based on project characteristics, work methods, personnel, and environment data. This method is expected to enhance the reliability and usability of risk assessments during the construction phase of construction projects.

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친환경건축물 인증제도 활성화를 위한 정보시스템 개선 연구 (A Study on the Improvement of Green Building Certification Information System)

  • 류수훈
    • 한국디지털건축인테리어학회논문집
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    • 제11권3호
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    • pp.5-16
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    • 2011
  • This study aims for improvement and rebuilding of the 'Green Building Certification Criteria Information System;GBCCIS'. To achieve this, improved information system has developed self-assessment program available on the web and to provide data about the target of Green Building Certification based on the 2010 revised criteria. The target building of Green Building Certification is Apartment, Office, Mixed-Use Building, School, property for sale, accommodation, and other facilities. Also, the information system about the Green building related technologies and techniques to take advantage of offer a variety of information was built. Green Building Certification Criteria web-site Established in this study has information and each menu and contents are linked to organic and high-utilization. Each menu is organized according to the used frequency and the group. Also this web-site is composed of information guide field, core service field, and other field. These improvement of Green Building Certification Criteria Information System can be a positive incentive measures for the activation of Green Building Certification Criteria easily by taking advantage of relevant information by users. And these will be possible to planning development of Green building technologies by introducing the latest Green building construction techniques applicable building. Also, to assess in advance by using self-assessment program in the design phase of building will lead to Green building design and provide the convenience of the application process and through database construction and share information of building assessment resources certified Green Building Certification Criteria will lead to the containment and fair assessment between cation authorities.

소비자 의류제품지식과 의복구매시 평가기준과의 관계 (The Relationship between Clothing product Bnowledge and Evaluative Criteria in Clothing Purchase Process)

  • 김은영
    • 한국의류학회지
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    • 제22권3호
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    • pp.353-364
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    • 1998
  • Consumer knowledge has been discussed as an important concept to understand information processing such as information search and evaluation process. It has been defined as the amounts and contents of information in consumer's memory accumulated by experiences. According to literature review, experts who have much knowledge are likely to retrieve their information related to products for a purchase efficiency. Therefore, they are likely to simplify the information processing for a choice. The purpose of this study was to examine the relationship between clothing product knowledge and evaluative criteria for a purchase. The results were as follows; First, it was found out that evaluative criteria were composed of four dimensions such as the management, the esthetic, the fitness and the brand. Therefore, it is implied that evaluative criteria for purchasing clothing products were multidimensional. Second, the level of objective knowledge was low, and consumers perceived that they didn't have much knowledge related with clothing products. Also, the relationships between objective and subjective knowledge were positive but low. Third, the evaluative criteria were effected by the level of consumer's knowledge significantly. In subjective knowledge, the subjects in a high group considered all criteria more deeply than in a low group. But there was a significant difference only in the esthetic between two groups in objective knowledge. The results of this study imply that consumer knowledge may influence evaluation process. Knowledgeable consumer would consider product attributes deeply for evaluating clothing products, and especially, the esthetic would be an important factor as an attribute including the instrumental and expressive functions in a purchase phase. Therefore, consumer knowl- edge would be a basis of predicting expert's information processing and managing heavy buyer or loyal consumers in apparel industry.

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우수유출 모형을 이용한 합류식하수관로시스템의 월류량, 월류빈도 산정 기준 결정 연구 (Criteria for calculation of CSO volume and frequency using rainfall-runoff model)

  • 이건영;나용운;류재나;오재일
    • 상하수도학회지
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    • 제27권3호
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    • pp.313-324
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    • 2013
  • It is widely known that untreated Combined Sewer Overflows (CSOs) that directly discharged from receiving water have a negative impact. Recent concerns on the CSO problem have produced several large scale constructions of treatment facilities, but the facilities are normally designed under empirical design criteria. In this study, several criteria for defining CSOs (e.g. determination of effective rainfall, sampling time, minimum duration of data used for rainfall-runoff simulation and so on) were investigated. Then this study suggested a standard methodology for the CSO calculation and support formalized standard on the design criteria for CSO facilities. Criteria decided for an effective rainfall was over 0.5 mm of total rainfall depth and at least 4 hours should be exist between two different events. An Antecedent dry weather period prior to storm event to satisfy the effective rainfall criteria was over 3 days. Sampling time for the rainfall-runoff model simulation was suggested as 1 hour. A duration of long-term simulation CSO overflow and frequency calculation should be at least recent 10 year data. A Management plan for the CSOs should be established under a phase-in of the plan. That should reflect site-specific conditions of different catchments, and formalized criteria for defining CSOs should be used to examine the management plans.