• Journal of KIBIM
• /
• v.1 no.1
• /
• pp.18-25
• /
• 2011

Construction cost estimation in the early phase provides the opportunity to make reasonable decisions related to the project. For estimating this cost, various methods have been developed. But several problems have been recognized like accuracy, relation beteewn design and cost etc. In this study, we developed the method of cost estimating for building parts. The modified method has defferent ratio of space functions to calculate cost more correctly. Also historical cost data is used in this modified method for architects to estimate cost conveniently. By this modified method, we expects architects should easily design buildings based on cost.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.29 no.4
• /
• pp.61-72
• /
• 2004

In this paper, we design sampling inspections and service capacities simultaneously for multi-products. Particularly, we extend Kim(2003) by introducing the fixed cost of providing services. We show that, due to the fixed cost considered, the cost function of a product is no longer linear or convex in terms of the level of service provision, and the total inspection is prefered to the small level of service capacity which results in high burden of the fixed cost. And we develop a simple framework to deal with this joint design problem for a product. Also we consider the problem of allocating the given number of the total service capacities among products. A dynamic programming algorithm is developed to determine the optimal allocation which minimizes the overall total cost of the system and the optimal allocation can be obtained with the considerably smaller computations than the total number of possible allocations. The results can be used to support planning decisions and to aid the joint design of inspections and service capacities for products.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.9 no.6
• /
• pp.117-123
• /
• 2009

There are two types of survivability. We find the characteristics of them for networks. And using the dual homing, we analysis the routing cost and link cost. Also we propose the cost-efficient heuristic design method of network topology in order to use survivability. By design samples, we analysis the cost efficiency and show that the new design method can be used to design network topology for survivability easily.

• Korean Institute of Interior Design Journal
• /
• v.22 no.5
• /
• pp.60-67
• /
• 2013

Preference studies regarding the elderly housing have been conducted to find out design features in specific needs of certain elderly groups with their various demographic characteristics. The purpose of this study was to investigate preference for accessible design features for the elderly and find out the differences in preference whether the cost information was given or not. Contrast to the previous studies, we suggested some alternatives to fulfill the accessible goals. Preference for each option was investigated and differences in preference with its cost information was also investigated. The total of 700 questionnaires were collected and analyzed using SPSS 18.0. As a result, to remove the level differences, respondents prefer installation of trench to installation of deck or ramp. When people received the cost information, the proportion of selection for each option has slightly changed. The findings of the study suggest that cost information is an important factor for choosing the option for removal of level difference, installation of sink design and holding bars, and installation of elevator. Regardless of age, the respondents prefer sliding door option (its cost is equal to the other option), one of the door option for bath room. It may be due to the relative small area for its installation. It was found that when people recognized the importance of the accessible design features higher, they are ore likely to pay for the option even though its cost is higher. The higher people evaluate the importance of accessible design features, the more they can pay for the option. In general, for the preference of alternatives, there are significant differences between the elderly and the younger.

• International Journal of Reliability and Applications
• /
• v.6 no.1
• /
• pp.31-39
• /
• 2005

An economic life test sampling plan for products with exponential lifetime distribution is developed. To reduce test time, a test plan with curtailed Type II censoring is considered. A cost model is constructed which involves three cost components; test cost, accept cost, and reject cost. Determination of optimal plan minimizing the expected average cost per lot is discussed with a constraint related to consumer's risk. Some numerical examples are provided.

• International conference on construction engineering and project management
• /
• 2022.06a
• /
• pp.823-830
• /
• 2022

The risk of project execution increases due to the enlargement and complexity of Engineering, Procurement, and Construction (EPC) plant projects. In the fourth industrial revolution era, there is an increasing need to utilize a large amount of data generated during project execution. The design is a key element for the success of the EPC plant project. Although the design cost is about 5% of the total EPC project cost, it is a critical process that affects the entire subsequent process, such as construction, installation, and operation & maintenance (O&M). This study aims to develop a system using machine-learning (ML) techniques to predict risks and support decision-making based on big data generated in an EPC project's design and construction stages. As a result, three main modules were developed: (M1) the design cost estimation module, (M2) the design error check module, and (M3) the change order forecasting module. M1 estimated design cost based on project data such as contract amount, construction period, total design cost, and man-hour (M/H). M2 and M3 are applications for predicting the severity of schedule delay and cost over-run due to design errors and change orders through unstructured text data extracted from engineering documents. A validation test was performed through a case study to verify the model applied to each module. It is expected to improve the risk response capability of EPC contractors in the design and construction stage through this study.

• Structural Engineering and Mechanics
• /
• v.49 no.1
• /
• pp.65-80
• /
• 2014

This paper reports on the development of a minimum cost design model and its application for obtaining economic designs for reinforced High Strength Concrete (HSC) T-sections in bending under ultimate limit state conditions. Cost objective functions, behavior constraint including material nonlinearities of steel and HSC, conditions on strain compatibility in steel and concrete and geometric design variable constraints are derived and implemented within the Conjugate Gradient optimization algorithm. Particular attention is paid to problem formulation, solution behavior and economic considerations. A typical example problem is considered to illustrate the applicability of the minimum cost design model and solution methodology. Results are confronted to design solutions derived from conventional design office methods to evaluate the performance of the cost model and its sensitivity to a wide range of unit cost ratios of construction materials and various classes of HSC described in Eurocode2. It is shown, among others that optimal solutions achieved using the present approach can lead to substantial savings in the amount of construction materials to be used. In addition, the proposed approach is practically simple, reliable and computationally effective compared to standard design procedures used in current engineering practice.

• Journal of Applied Reliability
• /
• v.18 no.3
• /
• pp.229-239
• /
• 2018

Purpose: There is a difficulty in Environmental Stress Screening (ESS) test design for weapon system's electrical/electronic components/products in small and medium-sized enterprises. To overcome this difficulty, I propose an easy ESS test design approach algorithm that is optimized with only one environment tolerance design information parameter (${\Delta}T$). Methods: To propose the mass production weapon system ESS test design for cost-effective optimization, I define an optimum cost-effective mathematical model ESS test algorithm model based on modified MIL-HDBK-344, MIL-HDBK-2164 and DTIC Technical Report 2477. Results: I clearly confirmed and obtained the quantitative data of ESS effectiveness and cost optimization along our ESS test design algorithm through the practical case. I will expect that proposed ESS test method is used for ESS process improvement activity and cost cutting of mass production weapon system manufacturing cost in small and medium-sized enterprises. Conclusion: In order to compare the effectiveness of the proposed algorithm, I compared the effectiveness of the existing ESS test and the proposed algorithm ESS test based on the existing weapon system circuit card assembly for signal processing. As a result of the comparison, it was confirmed that the test time was reduced from 573.0 minutes to 517.2minutes (9.74% less than existing test time).

• Journal of Ocean Engineering and Technology
• /
• v.23 no.1
• /
• pp.1-6
• /
• 2009

The paper describes results of a sensitivity study on an optimum mooring cost as a function of safety factor and allowable maximum offset of the offshore floating structure by finding the anchor leg component size and the declination angle. A harmony search (HS) based mooring optimization program was developed to conduct the study. This mooring optimization model was integrated with a frequency-domain global motion analysis program to assess both cost and design constraints of the mooring system. To find a trend of anchor leg system cost for the proposed sensitivity study, optimum costs after a certain number of improvisation were found and compared. For a case study a turret-moored FPSO with 3 ${\times}$ 3 anchor leg system was considered. To better guide search for the optimum cost, three different penalty functions were applied. The results show that the presented HS-based cost-optimum offshore mooring design tool can be used to find optimum mooring design values such as declination angle and horizontal end point separation as well as a cost-optimum mooring system in case either the allowable maximum offset or factor of safety varies.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1999.04a
• /
• pp.305-312
• /
• 1999

This study is intended to propose a systematic and practical life cycle cost(LCC) model for the development of the reliability-based seismic safety and cost-effective performance criteria for design and upgrading of long-span PC bridges. The LCC models consist of five cost functions such as initial cost, repair/replacement cost, human losses, road user cost, and indirect losses of regional economy. The proposed model Is successfully expressed in temrs of Park-Ang damage indices and life cycle damage probability obtained from SMART-DRAIN-2DX which is an existing algorithm for nonlinear time history analysis. The proposed LCC model is successfully applied to a viaduct constructed by PSM, in Seoul. Based on the observations, the proposed systematic procedure for the formulation of LCC model may be useful for the development of the reliability-based seismic safety and cost-effective performance criteria for design and upgrading of long-span PC bridges.