• Journal of Construction Engineering and Project Management
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• 제6권2호
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• pp.16-23
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• 2016

The use of inappropriate procurement methods to deliver construction projects has long been acknowledged as a major source of poor project performance and is particularly problematic for the Libyan Construction Industry. Poor procurement method selection has been recognised as a major contributory factor to frequent time and cost overruns. This paper offers a way of selecting specific procurement methods to maximize successful project performance. The methodology involves an intensive review of relevant literature, followed by a semi-structured questionnaire survey. The key findings of the study reveal that 11 out of its 12 common selection criteria exhibit a significant contribution to one or more project performance criteria (time, cost and quality). Project clients should therefore prioritise these criteria when selecting a design-bid-build method. Knowledge of the criteria that contribute positively to project performance will also enable clients to work out, prior to and during construction, the best measures and provisions for successful project outcomes.

• 한국건설관리학회논문집
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• 제8권2호
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• pp.75-83
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• 2007

최근 국내의 설계시공일괄방식(이하, 일괄방식)은 설계시공분리방식(이하, 기타방식)에 비해 높은 초기투자비용으로 인하여, 효용성에 대한 의문이 지속되고 있다 한편 발주방식별 성능을 평가한 기존의 연구를 살펴보면, 일괄방식은 공기측면과 품질측면에서 기타방식에 비해 우수한 것으로 보고되고 있다. 비교적 정량적 평가가 가능한 공기측면의 성과와 달리, 품질 측면의 성능은 해당 시설물의 발주자와의 면담을 통하여 만족도 수준을 평가하는 정성적인 평가가 대부분이다. 따라서 이 연구에서는 기존의 연구와는 달리, 2000년 이후 일괄방식과 기타방식으로 발주된 교량계획에 대한 성능수준을 평가하기 위하여, 설계도서 중심으로 계획성, 시공성, 유지관리성 등의 측면에서 평가해 보고자 한다. 이를 통하여 실제로 발주방식별 품질 등의 성능 측면에서 발주방식별 성능수준의 차이를 도출하였다.

• 한국지열·수열에너지학회논문집
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• 제15권4호
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• pp.16-23
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• 2019

Renewable energy systems are essential for the realization of zero energy building (ZEB). Moreover, the integrated system using solar and geothermal energy has been developed for heating, cooling and power of the building. However, there are few studies considering various design factors for system design. In this study, in order to develop the optimal design method for the system, the performance of the system was quantitatively compared and analyzed through dynamic simulation. Moreover, economic analysis was conducted based on the results of system performance. Through the performance and economic analysis results, the optimal design method of the tri-generation system was proposed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.54-57
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• 2004

In this paper, an optimal design method to have a good performance is researched. The parameters which are senstive to the performance are examined and determined by using evolutionary computations and commercial CAD program to have a good performance. Design method simulated is compared with conventional procedure.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.21-23
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• 2004

In this paper, an optimal design method to have good performance is researched. The parameters which are sensitive to the performance are examined and selected by using evolutionary computations and commercial CAD program to have good performance. Design method Simulated are compared with conrrentional procedure.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1220-1226
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• 2011

The purpose of this study is to assess the seismic performance of a reinforced concrete pier using ductility demand-based seismic design method and nonlinear earthquake analysis. A computer program named MIDAS/Civil(MIDAS IT,2009) for the analysis of the reinforced concrete pier was used. The bridge pier was designed by the ductility demand-based seismic design. In addition, a seismic performance was evaluated through both capacity spectrum method and nonlinear time history method. In order to determine the seismic performance of the bridge pier, the maximum response values from the capacity spectrum method and nonlinear time history analysis were compared each other.

• 한국시뮬레이션학회논문지
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• 제8권2호
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• pp.29-43
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• 1999

As real-time processing of data with large storage space is required in the era of multimedia, disk arrays are generally used as storage subsystems which be able to provide improved I/O performance. To design the cost-effective disk array, it is important to develop performance models which evaluate the disk array performance. Both queueing theory and simulation are applicable as the method of performance evaluation through queueing modeling. But there is a limit to the analytical method using queueing theory due to the characteristics of disk array requests being serviced in the parallel and concurrent manner. So in this paper we evaluate the disk array performance using simulation method which abstract disk array systems in the low level. Performance results were evaluated through simulation, so that mean response time, mean queueing delay, mean service time, mean queue length for disk array requests and utilization, throughput for disk array systems, can be utilized for capacity planning in the phase of disk array design.

• International Journal of Control, Automation, and Systems
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• 제5권6호
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• pp.691-700
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• 2007

This paper proposes a simple but effective design method of PID control using a numerical optimization method. In order to achieve both stability and performance, gain and phase margins and performance indices of step response directly compose of the cost function. Hence, the proposed approach is a multiobjective optimization problem. The main effectiveness of this approach results from the strong capability of the used optimization method. A one-dimensional example concerning gain margin illustrates the practical applicability of the optimization method. The present approach has many degrees of freedom in controller design by only adjusting related weight constants. The attained PID controller is compared with Wang#s and Ho#s methods, IAE, and ISE for a high-order process, and the simulation result for various design targets shows that the proposed approach achieves desired time-domain performance with a guarantee of frequency-domain stability.

• 한국정밀공학회지
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• 제6권4호
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• pp.126-135
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• 1989

본 연구에서는 공작기계의 동적설계를 합리적이고 효율적으로 수행하기 위하여 부분구조 합성법을 이용하여 부분구조의 감쇠 및 결합부의 특성행렬을 고려한 구조해석이론을 유도하고, 동적성능인 채터안정성 해석을 위하여 3차원 절삭동역학 이론을 사용하였다. 이를 결합하여 공작기계의 동적설계를 위한 전산프로그램 팩케지를 개발하고 국산 NC 선반의 성능개선에 응용하였으며, 부분구조 변경에 따른 전체 성능의 변화를 검토하였다.

• 한국지진공학회논문집
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• 제18권2호
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• pp.95-103
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• 2014

The current AISC341-10 standard specifiesa value of 0.02 radian for the minimum rotation capacity of connections for the intermediate steel moment frame system. However, despite of the advances realized in the domains of performance evaluation method and analysis method, research onthe minimum rotation capacity of the intermediate steel moment frame systemsatisfying the seismic performance has not been conducted in detail. In this study, the intermediate moment frame systemisdesigned with respect to current standards and the seismic performance in accordance with the rotational capacity of connections is evaluated using the seismic performance evaluation method presented in FEMA-P695. The minimum rotation capacity of intermediate steel moment frames required to satisfy seismic performance as well as the major design values affecting the seismic performance of moment frame areestimated. To that goal, the design parameters are selected and various target frames are designed. The analysis models of the main nonlinear elements are also developed for evaluating seismic performance. The resultsshow that the 20-story structure doesnot meet the seismic performance even if it satisfies the rotation capacity of 0.02 radian.