• Korean Journal of Construction Engineering and Management
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• v.22 no.6
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• pp.107-119
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• 2021

Recently, interest in remodeling apartment houses has been increasing due to problems such as a lack of parking spaces for old apartment houses. However, no method was suggested to predict the construction period of the apartment remodeling project. Unlike general apartment new construction, apartment remodeling construction involves demolition or reinforcement work, so a realistic remodeling construction period calculation plan differentiated from the existing construction period should be proposed. Therefore, this study intends to present a model for deriving the construction period of the underground parking lot of the apartment remodeling construction. Each construction period was calculated based on 19 activities of underground parking lot remodeling work through review of previous studies and expert advice. Activity's workload data and productivity data were derived to calculate the construction period, and the number of inputs and equipment inputs by Activity were determined to correct the productivity data. The construction period of Activity was calculated using the derived data, and the criteria for calculating the overlapping period for each Activity were presented to enable realistic construction period and scheduled schedule. As a result of predicting the accuracy of the construction period through the verification of the case complex, it is expected that it will be possible to predict the approximate construction period of the underground parking lot of the apartment remodeling construction in the future.

• Journal of Construction Engineering and Project Management
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• v.3 no.4
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• pp.1-4
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• 2013

Excavation is most commonly used activity in all construction projects. All contracting agencies prefer to use bigger and heavier excavators and dumpers on site to do excavations if quantity of excavation is huge. Estimation of required number of excavators and dumpers for completion of excavation could be rather a tedious process involving repetitive calculation on which professionals spend their valuable time. As the Information Technology is highly involved in construction section there os need to have IT model for estimation of number of excavators and dumpers. The developed model is useful to calculate required equipments within short period of time. The purpose of the developed IT model is to save the time and efforts of the construction professional. The paper discusses about model which can be used on site to estimate numbers of excavators and dumpers required for completion of certain quantity of excavation within the given time. The calculation considers various existing formulas and method to generate the output. This information could certainly be useful in planning equipments on construction project sites. The tool is user friendly where any non IT background person can use it on construction sites.

• Journal of the Society of Disaster Information
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• v.9 no.2
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• pp.195-205
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• 2013

Construction Management means a comprehensive plan of given the resources and the operation of the elements to complete the construction within the construction period. The construction period of these shall be determined by calculation based on reliable initial business. However, in actual field, inaccurate task duration is determined to the intuitive judgments of representative, reference of a similar project construction period of the past. As previous studies for the improvement of existing methods, This study presented a standard model that can be utilized in the early stages of construction projects for the TBM method operating by diameter (2.6m, 3.0m, 3.5m, 5.0m, 8.0m), and This study presented and calculated construction period which can estimated quickly the entire outline the construction period Therefore, When performing TBM construction work in the future, the total construction period which presented and analyze by TBM diameter, can be used as a useful material which plan and manage construction contracts, construction estimating, construction planning to the basic planning stage, and the basic design stage.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.30-40
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• 2007

The demand for light-rail construction projects has recently been increasing, and they are mostly supervised by private construction companies. Therefore, a private construction company that aim to raise gains from the operation of the facilities during the contract period greater than what they invested should b able to accurately calculate the costs from the aspect of Life Cycle Cost (LCC). In particular, a light-rail transit bridge that has a heavier portion from the aspect of the cost of light-rail transit construction requires a more accurate calculation method than the conventional LCC calculation method. For this, an LCC analysis model was developed and a cost breakdown structure was suggested based on literature review. The construction costs by shape of the upper part of a light-rail transit were calculated based on the cost breakdown system presented in this paper, and the cost generation cycle and cost unit price were collected and analyzed based on records on maintenance costs, rehabilitation and replacement. In addition, after forming some hypotheses in order to perform the LCC analysis, economic evaluation was conducted from the aspect of the LCC by using performance data by item.

• Korean Journal of Construction Engineering and Management
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• v.18 no.2
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• pp.30-37
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• 2017

In Korea, additional indirect costs generated from the time period extension of public construction projects have been studied. Practical claims against such costs are increasing. There are no clear criteria for calculating the delay cost caused by the extension, and thus calculation methods differ across entities. Logical valid calculation methods have also not been researched. Further, there are no Korean studies on the additional indirect cost caused by a suspension in a public construction project on a long-term continuing contract. The purpose of this research is to propose a method of calculating the indirect cost incurred by construction time extension that reflects the characteristics of Korean public construction projects. The cost patterns generated during construction periods were analyzed, and then the current criteria of calculating the indirect costs caused by the extension were examined. Following this, actual conditions and practices in the field were surveyed and the current calculation method was applied to a model case to compare the actual cost and that determined from the current calculation method. Issues with the current method were identified by this comparison. Based on this, this research proposes a method of calculating the total actual cost caused by a suspension in a public construction project that is appropriate for calculating the additional indirect cost generated by a suspension in a public construction project on a long-term continuing contract.

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

• Journal of Ocean Engineering and Technology
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• v.31 no.6
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• pp.405-412
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• 2017

Because of the rapid development of computer technology in recent years, wave models can utilize parallel calculations for the high-resolution prediction of open sea and coastal areas with high accuracy. Parallel calculations also allow national agencies in the relevant sectors to produce marine forecasting data through massive parallel calculations. Meanwhile, the eastern coast of the Korean Peninsula has been increasingly damaged by swell-like high waves, and many researchers and scientists are continuing their efforts to anticipate and reduce the damage. In general, the short-term transformation of swell-like high waves can be reproduced relatively well in the third generation wave models, but the transformation of relatively long period waves needs to be simulated with higher accuracy in terms of the nonlinear wave interactions to gain a better understanding of the low-frequency wave generation and development mechanisms. In this study, we developed a calculation module to improve the calculation of the nonlinear energy transfer in the 3rd generation wave model and integrated it into the wave model to effectively consider the nonlinear wave interaction. First, the nonlinear energy transfer calculation module and third generation model were combined. Then, the combined model was used to reproduce the wave transformation due to the nonlinear interaction, and the performance of the developed operation module was verified.

• Korean Journal of Construction Engineering and Management
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• v.18 no.4
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• pp.36-47
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• 2017

As a typical domestic subsea tunnel construction the Gadeok subsea tunnel applying the method of immersed tunnel has been completed and the Boryeong-Taean subsea tunnel is under construction using NATM. The high-speed railway subsea tunnels between the Honam and Jeju are under consideration, and the feasibility of constructing subsea tunnels with Japan and China is also under consideration. However, it is difficult to provide the process plan information for the construction work such as the analysis of the feasibility of the subsea tunnel and the prediction of the proper construction period because there is no case of domestic construction for it applying the shield TBM method. Due to economic and other reasons, government organizations are reluctant to apply the shield TBM, and there is lack of data on the construction process management field using the shield TBM method. Therefore, a standard construction process management system for the subsea tunnel is needed to analyze the feasibility of the subsea tunnel and to predict the proper construction period. By presenting the standard construction process management system of subsea tunnels such as WBS, Network Diagram, and construction period calculation model, I hope to contribute technically and economically to future subsea tunnel projects.

• Environmental and Resource Economics Review
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• v.17 no.3
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• pp.91-134
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• 2008

Korean district heating companies levy comprehensive construction fee on consumers in the beginning of construction period and the consumers' burden is much higher than those in any other network industries in Korea. It has also many problems such as inappropriate fee calculation method, cross subsidization, property right dispute, etc.. I show that the cut of construction fee by 30% and at the same time, the upward adjustment of tariff rates by 4~6% for 20 years on average will maintain current profitability based on the standard model simulation, I also suggest that fixed charge part of double tariff should be increased to 25% of total tariff and the cut of construction fee should be levied on fixed charge, directly to improve efficiency.

• Journal of Navigation and Port Research
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• v.27 no.2
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• pp.111-119
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• 2003

In order to improve navigational safety of ships, an ocean wave prediction model of high precision within a short time, dealing with multi-directional random waves from the information of the sea surface winds encountered at the planned ship's course, was introduced for construction of ocean wave forecasting system on the ship. In this paper, we investigated a sea disaster occurred by a stormy weather in the past. We analyzed the sea surface wind first and then carried out ocean wave hindercasting simulations according to the routes the sunken vessel. From the result of this study, we concluded that the sea disaster was caused by rapidly developed iou pressure system Okhotsk Sea and the predicted values by the third generation wave prediction model(WAM) was agreed well with the observed significant wave height, wave period, and directional wave spectrum. It gives a good applicability for construction of a practical on-board calculation system.