• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2006년도 정기 학술대회 논문집
• /
• pp.541-548
• /
• 2006

This study presents a structural cost optimization method for building frame system using high-strength steel members. In, this optimization method, the material cost of steel member is involved in objective function to find the optimal cost of building frame systems. Genetic Algorithm is adopted to optimizer to find structural cost optimization. The proposed adapted to structural design of 3.5 stories example buildings with buildings frame systems. As a result, The proposed optimization method can be effectively adapted to cost optimization of building frame systems using high-strength steel members.

• 한국농촌건축학회논문집
• /
• 제24권2호
• /
• pp.29-36
• /
• 2022

This study analyzed the effects of building and greenhouse structural code on the structural design and the greenhouse construction cost. The over-design possibility of greenhouse was analyzed when building structural code was applied using standard smart greenhouse drawings. The possibility of decrease in greenhouse construction cost was investigated if the currently applied building structural code was replaced with greenhouse structural code. As a result of comparing the member sizes with the standard drawings, building structural code was designed with 13%~74% more steel than greenhouse structural code. When building construction estimate was replaced with greenhouse construction estimate, it was possible to reduce the total construction cost of the glass greenhouse by 17% and that of the vinyl greenhouse by 14%. Since there is no standard construction estimate suitable for greenhouses, the wage unit price is set excessively, and the construction cost of the smart greenhouse is increasing. In conclusion, it is necessary to establish greenhouse structural code and greenhouse construction estimate to lower the greenhouse construction cost.

• 동력기계공학회지
• /
• 제9권2호
• /
• pp.106-111
• /
• 2005

After many casualties of conventional bulk carriers in recent years, a double hull bulk carrier was proposed to enhance the structural safety of a side shell and a transverse bulkhead. In this paper, two alternative structural designs of a double hull bulk carrier were carried out based on the Lloyd's rule. One has the double sided hull with longitudinal stiffeners and the other has that with a girder. The final structural design was examined in comparison with an existing single hull bulk carrier from the viewpoints of cargo hold capacity and the increases of weight and construction cost. Generally, the construction cost of a ship consists of the costs of material, labor and overhead cost. But, in this study, the relative construction cost concept was introduced to compare the economical validity more precisely. In this concept, fixed overhead cost is excluded in the assessment of construction cost, and only the variable overhead cost is added up to labor cost. As the result of this study, a double hull bulk carrier can be constructed within 1% increase of weight and construction cost.

• Computational Structural Engineering : An International Journal
• /
• 제2권1호
• /
• pp.19-23
• /
• 2002

A reliability-based cost-benefit model for the risk management of oil platforms in the formulation of optimal decisions based on life-cycle consideration is proposed. The model is based on structural risk assessments and the integration of social issues and economics into the management decision process. Structural risks result from the platform's exposure to the random environmental loading associated with the offshore site where it is located. Several alternative designs of a typical platform are proposed and assessed from the cost-effectiveness viewpoint. This assessment is performed through the generation of cost/benefit relationships that are used, later on, to select the optimal design.

• 국제학술발표논문집
• /
• The 3th International Conference on Construction Engineering and Project Management
• /
• pp.1223-1230
• /
• 2009

In the construction industry, Case-Based Reasoning (CBR) is considered to be the most suitable approach and determining the attribute weights is an important CBR problem. In this paper, a method is proposed for determining attribute weights that are calculated with attribute relation. The basic items of consideration were qualitative and quantitative influence factors. These quantitative factors were related to the qualitative factors to develop a Cost Drivers-structural equation model which can be used to estimate construction cost by considering attribute weight. The process of determining the attribute weight-structural equation model consists o 4 phases: selecting the predominant Cost Drivers for the SEM, applying the Cost Driers in the SEM, determining and verifying the attribute weights and deriving the Cost Estimation Equation. This study develops a cost estimating technique that complements the CBR method with a Cost Drivers-structural equation model which can be actively used during the schematic estimating phases of construction.

• Structural Engineering and Mechanics
• /
• 제59권5호
• /
• pp.933-950
• /
• 2016

Decks, interior beams, edge beams and girders are the parts of a steel floor system. If the deck is optimized without considering beam optimization, finding best result is simple. However, a deck with higher cost may increase the composite action of the beams and decrease the beam cost reducing the total cost. Also different number of floor divisions can improve the total floor cost. Increasing beam capacity by using castellated beams is other efficient method to save the costs. In this study, floor optimization is performed and these three issues are discussed. Floor division number and deck sections are some of the variables. Also for each beam, profile section of the beam, beam cutting depth, cutting angle, spacing between holes and number of filled holes at the ends of castellated beams are other variables. Constraints include the application of stress, stability, deflection and vibration limitations according to the load and resistance factor (LRFD) design. Objective function is the total cost of the floor consisting of the steel profile cost, cutting and welding cost, concrete cost, steel deck cost, shear stud cost and construction costs. Optimization is performed by enhanced colliding body optimization (ECBO), Results show that using castellated beams, selecting a deck with higher price and considering different number of floor divisions can decrease the total cost of the floor.

• 한국생활과학회지
• /
• 제21권6호
• /
• pp.1173-1184
• /
• 2012

This study estimates a structural model to examine the causal relationships among web browsing, switching cost, and site retention in the context of apparel shopping website. A total of 499 usable questionnaires were obtained from consumers aged from 20 to 49 years. For data analysis, exploratory factor analysis, confirmatory factor analysis and structural model were used. The result showed that consumer's perceived switching costs consisted of three factors: relationship cost, search cost and benefit loss cost. In estimated structural model, the relationship cost was influenced by leisure browsing; the search cost was influenced by informational browsing and leisure browsing; the benefit loss cost was influenced by leisure browsing. Especially, the leisure browsing was the most highly related to the benefit loss cost, and followed by relationship cost and search cost. However, hedonic browsing was not significantly related the factors of switching costs. The search costs significantly affected customer's intentions for site retention. A managerial implication was discussed for e-retailers in order to develop strategic switching costs in building long-term relationships with web browsers on the apparel shopping websites.

• Structural Engineering and Mechanics
• /
• 제31권1호
• /
• pp.11-24
• /
• 2009

In China, the oil and natural gas resources of Bohai Bay are mainly marginal oil fields. It is necessary to build both ice-resistant and economical offshore platforms. However, risk is involved in the design, construction, utilization, maintenance of offshore platforms as uncertain events may occur within the life-cycle of a platform under the extreme ice load. In this study, the optimum design model of the expected life-cycle cost for ice-resistant platforms based on cost-effectiveness criterion is proposed. Multiple performance demands of the structure, facilities and crew members, associated with the failure assessment criteria and evaluation functions of costs of construction, consequences of structural failure modes including damage, revenue loss, death and injury as well as discounting cost over time are considered. An efficient approximate method of the global reliability analysis for the offshore platforms is provided, which converts the implicit nonlinear performance function in the conventional reliability analysis to linear explicit one. The proposed life-cycle optimum design formula are applied to a typical ice-resistant platform in Bohai Bay, and the results demonstrate that the life-cycle cost-effective optimum design model is more rational compared to the conventional design.

• 대한조선학회논문집
• /
• 제42권3호
• /
• pp.284-289
• /
• 2005

A structural design system is developed for the optimum design of double hull tankers based on the multi-objective function method. As a multi-objective function method, Pareto optimal based random search method is adopted to find the minimum structural weight and fabrication cost. The fabrication cost model is developed by considering the welding technique, welding poses and assembly stages to manage the fabrication man-hour and process. In this study, a new structural design is investigated due to the rapidly increased material cost. Several optimum structural designs on the basis of high material cost are carried out based on the Pareto optimal set obtained by the random search method. The design results are compared with existing ship, which is designed under low material cost.

• 한국전산구조공학회논문집
• /
• 제22권3호
• /
• pp.277-287
• /
• 2009

최근 국내에서 400~600MPa급의 구조용 고강도강재가 생산되고 있으며, 큰 하중을 부담해야 하는 초고층건물에는 고강도강재의 사용이 효과적일 것으로 예상되나, 고강도강재의 적절한 사용법 및 적용사례 부족으로 인해 고강도강재는 일부 건축물에서 제한적으로 사용되고 있다. 그럼으로 본 연구에서는 고강도강재를 초고층건물에 이용할 수 있는 방법으로 최적화기법을 이용한 초고층건물 구조비용 최적설계기법을 개발하였다. 개발된 최적설계법은 강재의 강종별 재료 가격을 고려하며 강재의 강도와 크기를 결정함으로서 구조비용을 최소화 시킬 수 있다. 제안된 구조비용 최적설계법을 6개의 실제 초고층건물 구조설계에 적용하였으며, 경험에 의존한 구조 설계를 병행하여 개발된 최적설계법의 효율성과 적용성을 평가하였다. 개발된 초고층건물 구조비용 최적화기법은 경험에 의존한 설계에 비해 7~21%정도의 구조비용을 절감할 수 있었다. 또한, 제안된 최적설계법의 적용결과로서 얻어진 강재의 강도분포와 강종별 재료비용의 분석을 통해서 고강도강재를 초고층건물에 효과적으로 적용하기 위한 간략한 가이드라인을 제시하였다.