• Journal of Korean Society of Steel Construction
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• v.19 no.1
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• pp.15-27
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• 2007

Over the past decade, labor costs have increased relative to the cost of material hardware according to analysts in the construction industry. Therefore, the minimum weight design, which has been widely adopted in the literature for the optimal design of steel structures, is no longer the most economical construction approach. Presently, although connection- related costs is crucial in determining the most cost-effective steel structures, most studies on this subject focused on minimum-weight design or engaged in higher analysis. Therefore, in this study, we proposed a fabrication scheme for the most cost-effective moment-resisting steel frame structures that resist lateral loads without compromising overall stability. The proposed approach considers the cost of steel products, fabrication, and connections within the design process. The optimal design considered construction realities, with the optimal trade-off between the number of moment connections and total cost was achieved by reducing the number of moment connections and rearranging them using the combination of analysis that includes shear, displacement and interaction value based on the LRFD code and optimization scheme based on genetic algorithms. In this study, we have shown the applicability and efficiency in the examples that considered actual loading conditions.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.197-201
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• 2008

Conceptual cost estimates for domestic highway projects have generally been conducted using governmental unit-price references. Inaccuracies in governmental unit-price data has repeatedly addressed in the Korean construction industry which often lead to poor decision making and cost management practices. Thus, needs for developing a better way of conceptual cost estimating has been widely recognized. This research is considered as the first step in developing such model using real-world cost data based on actual construction activities. The data analyzed in this paper includes 41 P.S.C (Prestressed Concrete) Box bridges which broke into 4 categories based on construction methods such as I.L.M(Incremental Launching Method), M.S.S(Movable Scaffolding System), F.S.M(Full Staging Method), and F.C.M(Free Cantilever Method). Actual design documents; including actual cost estimating documents, drawings and specifications were carefully reviewed to effectively break down cost structures for PSC girder bridges. Among more than 40 cost categories for each P.S.C girder bridge type, 7 of them were identified which accounted for more than 95% of total construction cost (ILM: 99.47%, MSS: 99.22%, FSM: 98.18%, and FCM: 98.12%). In order to validate the clustering of cost categories, the variation of each cost category has been investigated which resulted in between -1.16 % and 0.59%.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.348-353
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• 2011

Recently the renewable energy has been used widely and the importance of renewable sources is bigger than before. So the government enforced a law to the public buildings to install the renewable energy facilities. The capacity of facilities is 5% of total construction cost until April 13, 2011. Since then, the government changed the law from 5% of total construction cost to 10% of predicted energy usage because of the practical use of the renewable energy facilities. So, in this study, the comparative analysis is conducted according to the law to the building installed PV system through the EnergyPlus simulation.

• Journal of the Korea Institute of Building Construction
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• v.8 no.1
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• pp.37-42
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• 2008

As use of construction equipment has been increasing continuingly, the proportion of equipment expense to the total construction cost has become higher. However, there is a difference between the equipment expenses section in 'Poom-Sam' and practical data, because 'Poom-sam' does not consider non-working days due to weather conditions, legal holidays and management conditions. Therefore, 'Poom-Sam' does not present a reasonable standard for estimating construction equipment expenses. In this study, to estimate realistic construction equipment operating hours, firstly, construction equipment was classified according to work, and weather conditions, in which each work could not be executed, were established. Then, weather data on Seoul and Busan($2004{\sim}2006$) and legal holidays were analyzed to suggest annual standard operating hours. The annual standard operating hours of earthmoving & excavating, compaction, and drilling equipment was estimated to be 1,430 hours, and lifting equipment, concrete paving equipment, asphalt paving equipment, concrete equipment, and crushing & conveying equipment were estimated to be 2,124 hours, 1,156hours, 1,188hours, 1,688hours, and 2,152hours respectively.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.4
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• pp.189-199
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• 2002

This study is intended to propose a systematic procedure for the development of the conditional assessment based on the safety of structures and the cost effective performance criteria for designing and upgrading of bridge structures. As a result, a set of cost function models for a life cycle cost analysis of bridge structures is proposed and thus the expected total life cycle costs (ETLCC) including initial (design, testing and construction) costs and direct/indirect damage costs considering repair and replacement costs, human losses and property damage costs, road user costs, and indirect regional economic losses costs. Also, the optimum safety indices are presented based on the expected total cost minimization function using only three parameters of the failure cost to the initial cost (${\tau}$), the extent of increased initial cost by improvement of safety (${\nu}$) and the order of an initial cost function (n). Through the enough numerical invetigations, we can positively conclude that the proposed optimum design procedure for bridge structures based on the ETLCC will lead to more rational, economical and safer design.

• Architectural research
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• v.7 no.1
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• pp.11-18
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• 2005

In today's building industry the emphasis has been geared more towards construction, thus building maintenance and life cycle have been neglected until now. A direct result of this neglect is the rapid aging of building, which leads to more cost-effective decision making methods for the prolongation of building life span. The following study is conducted in the area of Daegu and Seoul in order to develop the estimation analysis method of the annual operation cost of the Korean high-rise condominiums for the cost-effective decision making support through mathematical and statistical analyses including the present value and standardized measurement corrections. Based on the assumption that the life expectancy of the high rise condominium is 50 years, initial cost is ￦421,212/$m^2$, and a total sum of yearly operation cost during life expectancy is ￦2,154,499//$m^2$), yearly accumulated operation cost is shown as below: $AOC=0.7097t^4-38.803t^3+806.95t^2+11045t-496.52$ ($R^2=0.98$) (Here, AOC = Accumulated Operation Cost, t = given years)

• Korean Journal of Construction Engineering and Management
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• v.8 no.1 s.35
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• pp.87-95
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• 2007

If construction process operate composing work team by judgment manager's experience, possibility that progress of construction process becomes as inefficient is much. But, If produce optimal proposal of resources allocation, construction cost and duration through simulation at work plan step, work schedule because do quantification efficient operate do on. When plan construction process in this research, resources allocation by change of work team operation change, resources cost loss, total cost, optimal proposal of construction duration tentative plan of numerical formula model that can do simulation propose. Apply and revealed to apartment house framework which horizontal work area of process and vertical work area are composed as is each different construction process to verify proposed numerical formula model. Achieved efficiency than work team's operation results which apply numerical formula model that is presented in this research and enforce simulation is applied in actuality example construction.

• Journal of the Korea Institute of Building Construction
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• v.15 no.4
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• pp.397-404
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• 2015

Construction equipment cost is critical to estimate the total construction costs, particularly in large and complicated projects. Public construction projects are typically estimated using the Poom-Saem which includes hourly rates for workers and equipments. Despite its importance, the construction equipment cost may not properly reflect the current market value because it is being updated every six years at most. To keep the data for construction equipment cost estimation up to date, it is highly recommended to use the standard market price that is reported each year by the Ministry of Security and Public Administration (MOSPA). However, there is still a wide gap to directly adopt the standard market price for updating the construction equipment prices. Therefore, this paper suggests an effective way to develop an ordinary management systems for updating construction equipment prices in the Poom-saem based on the standard market price.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.642-652
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• 2007

Many contracting firms and project managers in the construction industry have started to utilize multi objective optimization methods to handle multiple conflicting goals for completing the project within the stipulated time and budget with required quality and safety. These optimization methods have increased the pressure on decision makers to search for an optimal resources utilization plan that optimizes simultaneously the total project cost, completion time, and crashing cost by considering indirect cost, contractual penalty cost etc., practically charging them in terms of direct cost of the project which is fuzzy in nature. This paper presents a multiple fuzzy goal programming model (MFGP) that supports decision makers in performing the challenging task. The model incorporates the fuzziness which stems from the imprecise aspiration levels attained by the decision maker to these objectives that are quantified through fuzzy linear membership function. The membership values of these objectives are then maximized which forms the fuzzy decision. The problem is solved using LINGO 8 optimization solver and the best compromise solution is identified. Comparison between solutions of MFGP, fuzzy multi objective linear programming (FMOLP) and multiple goal programming (MGP) are also presented. Additionally, an interactive decision making process is developed to enable the decision maker to interact with the system in modifying the fuzzy data and model parameters until a satisfactory solution is obtained. A case study is considered to demonstrate the feasibility of the proposed model for optimization of project network parameters in the construction industry.

• IE interfaces
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• v.10 no.1
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• pp.237-248
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• 1997

The purpose of this study is to make an economic analysis of power plant utilities by examining electricity generating costs with environmental consideration. Economic growth has caused pollutant emission, and subsequent environmental pollution has been identified as a very real limit to sustainable development. Considering the enormous role of electricity in the national economy, it is thus very important to study the effect of environmental regulations on the electricity sector. Because power utilities need large investments during construction, operation and maintenance, and also require much construction lead time. Economic analysis is the very important process in the electric system expansion planning. In this study, the levelized generation cost method is used in comparing economic analysis of power plant utilities. Among the pollutants discharged of the electricity sector, this study principally deals with the control activities related only to $CO_2$, and $NO_2$, since the control cost of $SO_2$, and TSP (Total Suspended Particulates) is already included in the construction cost of utilities. The cost of electricity generation in a coal-fired power plant is compared with one in an LNG combined cycle power plant. Moreover this study surveys the sensitivity of fuel price, interest rate and carbon tax. In each case, this sensitivity can help to decide which utility is economically justified in the circumstance of environmental regulations.