• 제목/요약/키워드: Demands Analysis

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다층 구조물과 등가 단자유도계의 에너지 요구량 비교 (Comparison of Energy Demand in Multi-Story Structures and Equivalent SDOF Systems)

  • 최현훈;원영섭;김진구
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2003년도 봄 학술발표회 논문집
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    • pp.19-26
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    • 2003
  • In energy-based design, the structures are generally transformed into equivalent SDOF systems to obtain the input and the dissipated energy. In this study the energy demands in multi-story structures were compared with that of equivalent single degree of freedom systems to validate the transformation method. Three-, eight-, and twenty-story steel moment-resisting frames and buckling restrained braced frames are compared with those of equivalent single degree of freedom systems. Sixty earthquake ground motions recorded in different soil conditions were used to compute the input and hysteretic energy demands in model structures. According to the analysis results, in 3 and 8-story structures the hysteretic energy demands computed in the equivalent SDOF structures are compatible with those computed in the original MDOF structures, while in the 20-story structures the transformed equivalent structures underestimated the hysteretic energy demands.

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안전참여 활동에 대한 직무요구-자원 모형의 적용 및 안전 자기효능감의 조절효과 (Applying the Job Demands-Resources model to safety participation and the moderating effect of safety self-efficacy)

  • 안관영
    • 대한안전경영과학회지
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    • 제16권1호
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    • pp.109-117
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    • 2014
  • This paper reviewed the relationship between job demands/resources and safety participation, and the moderating effect of safety self-efficacy. Based on the responses from 247 employees, the results of multiple regression analysis appeared as follow; 1) job demands factors(role conflict, role ambiguity and role overload) effect negatively on safety participation. 2) job resources factors(autonomy and social support) effect positively on safety participation. 3) safety self-efficacy moderates positively 3 relationships-between role conflict and safety participation, between role ambiguity and safety participation, between social support and safety participation.

건축구조물의 시스템 연성요구도 평가를 위한 대표응답의 활용 (Responses of Equivalent SDOF System for System Ductility Demands Evaluation of Multistory Building Structures)

  • 최원호;이동근
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 봄 학술발표회 논문집
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    • pp.446-453
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    • 2001
  • System-level ductility is an essential parameter for seismic performance evaluation of multistory building structures. The ductility demands for single degree of freedom structures or individual structural members can be determined easily. However, there is no clearly established method to determine the ductility demands for structural systems. The system ductility demands are estimated in this study by the equivalent SDOF system methods and proposed method which used the representative responses obtained from the MDOF systems directly. And seismic performance of building structures is evaluated by the modified Capacity Spectrum Method using the representative responses, and the result was compared with those of the inelastic time history analysis.

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복합포아송 수요를 가지는 CONWIP 시스템에서 고객집단의 성능평가 (Order Based Performance Evaluation of a CONWIP System with Compound Poisson Demands)

  • 박찬우;이효성
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 2004년도 추계학술대회 및 정기총회
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    • pp.8-12
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    • 2004
  • In this study we consider a CONWIP system in which the processing times at each station follow a Coxian distribution and the demands for the finished products arrive according to a compound Poisson process. The demands that are not satisfied are backordered according to the number of demands that exist at their arrival instants. For this system we develop an approximation method to calculate order based performance measures such as the mean time of fulfilling a customer order and the mean number o: customer orders. For the analysis of the proposed CONWIP system, we model the CONWIP system as a closed queueing network with a synchronization station and analyze the closed queueing network using a product form approximation method. Numerical tests show that the approximation method provides fairly good estimation of the performance measures of interest.

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로트 단위로 가공되는 CONWIP 시스템의 근사적 분석 (Approximate Analysis of a CONWIP System with a Lot Production)

  • 이효성;이정은
    • 산업공학
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    • 제11권3호
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    • pp.55-63
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    • 1998
  • In this study we consider a CONWIP system in which the processing times at each station follow an exponential distribution and the demands for the finished products arrive according to a compound Poisson process. The demands that are not satisfied instantaneously are assumed to be lost. We assume that the lot size at each station is greater than one. For this system we develop an approximation method to obtain the performance measures such as steady state probabilities of the number of parts at each station, average number of parts at each station and the proportion of lost demands. For the analysis of the proposed CONWIP system, we model the CONWIP system as a closed queueing network with a synchronization station and analyze the closed queueing network using a product form approximation method. A recursive technique is used to solve the subnetwork in the application of the product-form approximation method. To test the accuracy of the approximation method, the results obtained from the approximation method were compared with those obtained by simulation. Comparisons with simulation have shown that the accuracy of the approximate method is acceptable.

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Demand Analysis of Clothing and Footwear: The Effects of Price, Total Consumption Expenditures and Economic Crisis

  • Kim, Kisung
    • 한국의류학회지
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    • 제36권12호
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    • pp.1285-1296
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    • 2012
  • This study investigates the effects of changes in price, total consumption expenditures and economic sitations on Korean household demands for clothing and footwear using time-series data. The clothing and footwear category was reclassified as clothing, footwear and clothing services items for the demand analysis. This study utilized the Linearized Almost Ideal Demand System (LAIDS) model to analyze household demand. The results indicate that price and total consumption expenditures are significantly related to Korean household consumption expenditure allocations for clothing and footwear items. The effects of the IMF bailout crisis in 1997 and the global financial crisis in 2008 on household expenditure shares for clothing and footwear items were very weak and statistically insignificant. All the demand elasticities were estimated with respect to total consumption expenditures and prices. Clothing was expenditure elastic (greater than one) and other items were classified as inelastic. All the own price elasticities of demands were negative (other than clothing). Through the estimations of cross price elasticity the relationships between the demands for items and other item prices were evaluated (i.e., substitutes and complements).

정적해석을 이용한 내진성능평가의 타당성 (Validity of Seismic Performance Evaluation Using Static Analysis)

  • 원학재;한상환;이리형
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 봄 학술발표회 논문집
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    • pp.475-480
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    • 2001
  • The purpose of this study is to evaluate the validity of seismic performance evaluation using static analysis. For this purpose, Ordinary Moment Resisting Steel Frames(OMRSF) for different heights(3, 6 ,9, 12 story) and seismic zones(Zone 2A, 2B, 3, 4) were designed in compliance to AISC LRFD 1993 Seismic Provisions and NEHRP 1994 Guidelines. Nonlinear Static Procedure(NSP) and Nonlinear Dynamic Procedure(NDP) with a set of ground motion record were used to evaluate seismic demands in OMRSFs. Using the DRAIN-2DX program, this study compares peak displacement demands(Target Displacement) proposed by FEMA 273 with the peak roof displacement demands obtained from the inelastic time history analyses. Based on the results, the validity of procedure of seismic demand evaluation using Target Displacement is discussed.

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Evaluation of ASCE 61-14 NSPs for the estimation of seismic demands in marginal wharves

  • Smith-Pardo, J. Paul.;Reyes, Juan C.;Sandoval, Juan D.;Hassan, Wael M.
    • Structural Engineering and Mechanics
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    • 제69권1호
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    • pp.95-104
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    • 2019
  • The Standard ASCE 61-14 proposes the Substitute Structure Method (SSM) as a Nonlinear Static Procedure (NSP) to estimate nonlinear displacement demands at the center of mass of piers or wharves under seismic actions. To account for bidirectional earthquake excitation according to the Standard, results from independent pushover analyses in each orthogonal direction should be combined using either a 100/30 directional approach or a procedure referred to as the Dynamic Magnification Factor, DMF. The main purpose of this paper is to present an evaluation of these NSPs in relation to four wharf model structures on soil conditions ranging from soft to medium dense clay. Results from nonlinear static analyses were compared against benchmark values of relevant Engineering Design Parameters, EDPs. The latter are defined as the geometric mean demands that are obtained from nonlinear dynamic analyses using a set of 30 two-component ground motion records. It was found that SSM provides close estimates of the benchmark displacement demands at the center of mass of the wharf structures. Furthermore, for the most critical pile connection at a landside corner of the wharf the 100/30 and DMF approaches produced displacement, curvature, and force demands that were reasonably comparable to corresponding benchmark values.

의료산업체 수요맞춤형 물리치료교육과정 개발에 관한 연구 (A Study on the Development Planning for Physical Therapy Curriculum According to the Demands of the Medical Institution)

  • 서현규;이재홍;권원안
    • PNF and Movement
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    • 제10권3호
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    • pp.53-66
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    • 2012
  • Purpose : This research has been studied physical therapy curriculum according to the demands of the medical institution. Methods : The subjects of this study were 88 physical therapists. The subjects were divided by OS(n=41) and NS(n=47) group. The results of research were analyzed using independent t-test with average and standard deviations as the statistical methods for data analysis. Results : the results of the study were as follow : First, it was needed on the development planning for physical therapy curriculum according to the demands of the medical institution. Second, tests of independent t-test were a statistically significant difference between OS and NS group on the demands of the medical institution. Third, it was needed that time tables on physical therapy curriculum were partially regulated by the demands of the medical institution. Conclusion : We suggest to change the curriculum of physical therapy. It is more accurately reflected the rigor of the high-quality education preparation needed for current and future practice.

추론 과제의 인지적 난이도 수준에 따른 추론 과정 구성요소 분석 -고등학교 수준 수열 단원을 중심으로- (An Analysis of Components of Reasoning Process according to the Levels of Cognitive Demands of the Reasoning Tasks -Focused on the Highschool level Mathematical Sequence-)

  • 오영석
    • 한국수학교육학회지시리즈E:수학교육논문집
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    • 제33권3호
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    • pp.395-423
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    • 2019
  • 본 연구의 목적은 향후 수학교과서의 추론 과제 개발에 대한 시사점을 제공하기 위하여, 고등학교 수준 수학교과서 3종을 연구 대상으로 수열 단원에 제시된 추론 과제의 인지적 난이도 수준과 추론 과정 구성요소를 분석하는 것이다. 연구 결과, 3종의 수학교과서의 수열 단원에 제시된 추론 과제의 대부분이 인지적 난이도 수준이 낮은 것으로 나타났으며, 인지적 난이도 수준이 낮은 추론 과제는 하나의 추론 과정 구성요소만을 요구하는 것으로 나타났다. 반면에 추론 과제의 일부만이 인지적 난이도 수준이 높은 것으로 나타났으며, 인지적 난이도 수준이 높은 추론 과제는 다양한 추론 과정 구성요소를 요구하는 것으로 나타났다. 이러한 연구 결과를 바탕으로 인지적 난이도 수준이 낮은 추론 과제보다는 학생들에게 다양한 추론 과정의 학습기회를 제공하고 추론의 본질을 심도있게 이해시킬 수 있는 인지적 난이도 수준이 높은 추론 과제 개발에 대한 필요성을 제시하였다.