• Korean Journal of Construction Engineering and Management
• /
• v.6 no.6 s.28
• /
• pp.171-180
• /
• 2005

Public rental housing is constructed, owned, and managed by the public sector. The public institution for the public rental housing controls the whole building life cycle from the construction to the demolition. The construction company for the house built for sale is strongly interested in the cost for the initial investment, while the public institution is more focused on the maintenance cost for the preservation of the buildings Nevertheless, the maintenance cost of the public rental housing has been only managed as the accounting factor without the systemic research and analysis on the actual condition. This paper shows how expenses are related to the degree of obsolescence and presents the differences of the maintenance costs by the housing area and expenditure trends (vs time) of the maintenance costs, through analyzing time series data of public rental housing maintenance cost. Further, this paper helps understanding the causes of the differences of the maintenance costs by housing areas and characteristics of the expenditure trends. After all, this paper contributes to the improvement of the reliability and the practicality for the Life Cycle Cost modeling and the maintenance cost estimating.

• Journal of the Korea Institute of Building Construction
• /
• v.13 no.4
• /
• pp.321-332
• /
• 2013

Costs and expenses are intertwined and incurred throughout an entire construction project, even from the pre-construction phase, and each phase has a different impact on the life cycle cost (LCC). However, the cost breakdown structure (CBS) is different in each phase of a building construction project, which makes it hard to reasonably calculate construction cost. For this reason, the boundary conditions were analyzed in this study based on the life cycle cost break structure (LCCBS). In addition, breakdown factors were analyzed based on the boundary conditions to derive a linkage method. The validity of the linkage method was verified through application to actual construction projects. Through the analysis, it was found that the problem of items being left out was reduced by more than 97.2 percent, and the work was done an average of 6 hours faster compared to the conventional method. It is expected that by applying the new LCC system, LCC will be both reduced and calculated in a more efficient manner.

• Korean Journal of Construction Engineering and Management
• /
• v.19 no.4
• /
• pp.61-69
• /
• 2018

Research on additional indirect cost due to construction period extension in general contracts has continuously been active whereas the same for the subcontract operations has not been. In this research, we review previous research on evaluation methods for additional indirect costs which are widely being used on construction sites as well as previously proposed methods altogether, applying them to analyze model-cases for comparison. We acknowledge that this pattern for construction cost fluctuation over the construction period demonstrates an S-curve. This S-curve shaped indirect cost occurrence is then used to generate model-cases that are used throughout the research which models we applied previous evaluation methods on. Finally in pursuit of finding out some problems of evaluation methods, we came to derive a conclusion that the "Average Actual Cost Evaluation Method on Extended Duration," which, in turn, were proved to be valid for application on general contracts, was also valid for general application on subcontractor operations.

• Korean Journal of Construction Engineering and Management
• /
• v.19 no.5
• /
• pp.43-52
• /
• 2018

Generally, research on construction cost has been done mostly regarding its direct cost, thus model regarding indirect cost lacks attention. This research seeks to introduce a model to predict on-site overhead cost for apartment construction projects, which constitutes a big portion in Korean construction industry. We devised an equation of 9th degree via curve-fitting, using multiple on-site actual expense data, which can be used to calculate per-progress rate, per-day on-site overhead cost. We further show prospective usage of the model by applying it on construction projects sizing about 30 billion won. Regarding the fact that previous studies could not recognize pattern changes of a total on-site overhead cost, this model is worthy of its conveniency and thoroughness, as well as providing reasonal ground for its derivation in predicting on-site overhead cost of apartment construction projects.

• Journal of the Korea Society for Simulation
• /
• v.29 no.4
• /
• pp.85-94
• /
• 2020

In determining the feasibility of planning and launching railway transportation projects, various decision-making processes are essentially required. LCC(Life Cycle Cost) value including total construction cost and operation cost is estimated in approximation Model with rough guideline. In this study, modeling and simulation-based analysis method is proposed to support the decision making process of railroad transportation and derivation of LCC. Firstly, cost analysis model was constructed by collecting various existing rail transportation business data to enable analyze based on numerical data, and the result were analyzed by DOE(Design Of Experiments) and RSM (Response Surface Method) simulation. Professional commercial software tools were used for effective model construction and simulation. In order to verify the research results, the actual railroad transportation projects were selected, and the results of the analysis were compared.

• Journal of the Korea Convergence Society
• /
• v.9 no.3
• /
• pp.223-230
• /
• 2018

This study analyzes the cost fluctuation between cost in contract stage and cost in adjustment stage in defense R&D project. This research shows that certain costs hold with the cost fluctuation and their degree of influence. The results of first analysis show that 13 out of 17 costs have a relationship with the cost fluctuation. The estimate of direct labor cost is positive and significant at the 0.1% level(direct labor = 1.022, t = 38.355). The estimate of amount of cost paid to subcontractor is positive and significant at the 1% level(amount paid to subcontractor = 0.942, t = 51.894). The results of second analysis show that all the direct costs have a relationship with the cost fluctuation(The fact that cost system is focused on direct labor cost is a consideration in this analysis). The estimate of direct labor cost is positive and significant at the 0.1% level(direct labor = 2.014, t = 21.787). The estimate of amount of cost paid to subcontractor is positive and significant at the 0.1% level(amount of cost paid to subcontractor = 1.068, t = 15.636). This finding supports a proposal theory that cost system is focused on direct labor cost through actual proof analysis and an inducement that amount of cost paid to subcontractor is a way to reduce the R&D cost.

• Korean Journal of Computational Design and Engineering
• /
• v.21 no.1
• /
• pp.61-68
• /
• 2016

Since past till now, automotive wiring harness has been designed and produced under the method of part number list. However, the number of options has increased gradually on the basis of customer's needs and car manufacturer's policy, thereby bringing about an increase in the number of classified parts. Because of a large number of classified parts, cost estimates for manufacturing and production planning are more important than ever. However, the pre-existing manufacturing bill of material abbreviated as BOM is only focused on the list of materials used for actual manufacturing, and as such there have been limits to other fields or areas of usage except for manufacturing. In essence, the present paper is concerned with our study conducted on modular BOM as one of planning BOM. On such basis, we have been able to completely use a method by which to have access, make an option units' calculation in wiring harness manufacturing, and build an efficient system for cost estimates in manufacturing as well.

• Smart Structures and Systems
• /
• v.16 no.4
• /
• pp.743-758
• /
• 2015

This paper presents an advanced life cycle cost (LCC) analysis of a ground source heat pump (GSHP) system and suggests a smart operation mode with a thermal performance test (TPT) and an energy pile system constructed on the site of the Incheon International Airport (IIA). First, an economic analysis of the GSHP system was conducted for the second passenger terminal of the IIA considering actual influencing factors such as government support and the residual value of the equipment. The analysis results showed that the economic efficiency of the GSHP system could be increased owing to several influential factors. Second, a multiple regression analysis was conducted using different independent variables in order to analyze the influence indices with regard to the LCC results. Every independent index, in this case the initial construction cost, lifespan of the equipment, discount rate and the amount of price inflation can affect the LCC results. Third, a GSHP system using an energy pile was installed on the site of the construction laboratory institute of the IIA. TPTs of W-shape and spiral-coil-type GHEs were conducted in continuous and intermittent operation modes, respectively, prior to system operation of the energy pile. A cooling GSHP system in the energy pile was operated in both the continuous and intermittent modes, and the LCC was calculated. Furthermore, the smart operation mode and LCC were analyzed considering the application of a thermal storage tank.

• The Journal of Korean Medicine
• /
• v.29 no.1
• /
• pp.15-24
• /
• 2008

Objectives : The purpose of this study is to reexamine current oriental medical treatment fees based on valuation of input resources which are the treating time, the treatment's difficulty, and the material cost. Methods : This study obtained the following results by reviewing the answers given by 172 oriental medical doctors from March 1 to April 15, 2006. To investigate material cost, we took inventory of treatment materials used by 2 oriental hospitals. Results : The current system does not reflect well enough the treating time and treatment's difficulty. Considering current oriental treatment fees, material costs are too much of doctors' fees. Especially, Wang-ssuk-dduem, which is another form of moxibustion treatment, was spent as much as 74.6% on materials cost. Conclusions : The findings suggest the current oriental treatment fees should be revised to reflect the actual input resources into oriental medical doctor activities and to avoid a distortion of physicians' behavior.

• Journal of Electrical Engineering and Technology
• /
• v.12 no.4
• /
• pp.1397-1405
• /
• 2017

As the introduction of wind power is steadily increasing, negative effects of wind power become more important. To operate a power system more reliable, the system operator needs to recognize the maximum required capacity of available generators for a certain period. For recognizing the maximum capacity, this paper proposes a methodology to determine an optimal reserve requirement considering wind power, for the certain period in the mid-term perspective. As wind speed is predicted earlier, the difference of the forecasted and the actual wind speed becomes greater. All possible forecast errors should be considered in determining optimal reserve, and they are represented explicitly by the proposed matrix form in this paper. In addition, impacts of the generator failure are also analyzed using the matrix form. Through three main stages which are the scheduling, contingency and evaluation stages, costs associated with power generation, reserve procurement and the usage, and the reliability cost are calculated. The optimal reserve requirement is determined so as to minimize the sum of these costs based on the cost/reliability analysis. In case study, it is performed to analyze the impact of wind power penetration on the reserve requirement, and how major factors affect it.