• Proceedings of the KSR Conference
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• 2005.11a
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• pp.482-487
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• 2005

In the most current Turn-key bidding and Alternative design, is going to establish maintenance plan along with a economical assessment (VE/LCC assessment etc). Generally, establishment of maintenance plan is based on past experiences that are decided upon sensor position and amount with analytic or mechanical control section. But, it is more reasonable that maintenance plan based on level of significance for Probabilistic Risk, with presuming damage probability assessment of structural fracture scenarios. Therefore, in this study it is considered about the technique that an improved maintenance plan of railroad structures using PRA (Probabilistic Risk Assessment) on the basis of structural reliability theory. For this, in the paper, Preventive maintenance plan based on PRA is suggested with an application example of Pansong-Line (Line number 3) railway in Pusan works that actually executed Turn-key design.

• Proceedings of the ESK Conference
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• 1996.04a
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• pp.151-151
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• 1996

컴퓨터 기술의 급격한 발전은 현실세계의 각종 현장을 컴퓨터 가상공간 내에서 시험할 수 있도록 하고 있다. 최근들어급격한 발전이 이루어지고 있는 가상현실(Virtual Reality) 기술과 인간의 감성을 중시한 감성공학적 접근방법 론의 활용은 그 적용범위가 점차 확대되어 가고 있는 상황으로, 제조기업에서 사용되고 있는 통합생산 정보시스템 (Computer Integrated Manufacturing)과의 접목으로 가상공장(Virtual Factory) 시스템을 구현할 수가 있다. 가상공장시스 템은 제조기업의 Businiss를 Design & Engineering, Production Planning & Control, Manufacturing의 3가지 프로세스로 분류한다. 그리고 각 프로세스별로 현재의 CIM시스템에 대한 하부시스템을 검토하고, 인간 중심의 가상기업시스템을 구현 하는데 보완이 되어야 할 사항과 이에 대한 해결 대안으로 Design & Engineering Process에서는 Virtual Engineering(VE) Sub-system, Manufacturing Process에서는 Virtual Manufacturing(VM) Sub-system으로 분류하여 각 Sub-system별 구성모듈을 설계하고 상호간의 Interface 사항을 설계하므로서 가상공장시스템 구현을 위한 기본 요구사항과 조건을 제시하고자 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.12
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• pp.2343-2351
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• 2007

In this paper, we describe the design and implementation of time-varying magnetic field stimulator. Novel design for power supply part to generate high repetitive magnetic field for very short time(less than $300{\mu}s$) was achieved. Using the novel designed power supply part and the circular type coil probe, we've achieved high magnetic field up to 1.2 Tesla in 20Hz repetition rate.

• Journal of Korean Society of Steel Construction
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• v.14 no.3
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• pp.395-402
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• 2002

This study proposed a muti-objective optimum design method for rational optimizing of orthotropic steel deck bridges. This multi-objective optimum design method was found to be effective in optimizing multi-objective problems, considering cost and deflection functions. It may ve difficult to optimize orthotropic steel deck bridges using a conventional optimization, since the bridges have several parts and show complex structural behaviors. Therefore, the Pareto curve can be obtained by performing the multi-objective optimization for real orthotropic steel deck bridges, using the multi-level technique with excellent efficiency. A reasonable and economical design can be attained using the Parato curve in the cost and deflection functions of the bridge. Thus, more reasonable design values can be determined based on a comparison with those using a conventional design procedure.

• Journal of the Korean Geosynthetics Society
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• v.13 no.1
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• pp.1-9
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• 2014

Expansion of a roadway on a soft ground can cause settlement of the existing road during embankment construction due to the consolidation characteristics of the soft soil. Many problems related to construction and maintenance, such as deterioration of the surface, decreased safety, and decreased structural stability, could affect the existing road. This scenario is especially true if the roadway foundation is a deep thick soft ground. Therefore, engineers should carefully select a proper design based on the characteristics of the soil layer. In this study, the expansion of the second branch of the Namhae Expressway was selected as the target site because this expressway has been constructing on a soft soil layer approximately 50 m thick. The original design was reviewed, problems were discussed and alternative was proposed through value engineering job plan phases: investigation, speculation, evaluation, development and presentation. In addition, the proposed alternative was evaluated on cost, function and value improvement. Compared to the original design, the proposed alternative saved cost and improved the function and overall value.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.25-31
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• 2007

Nuritkum Square Project is a IT Complex which is being constructed in Digital Media City. The project consists of several buildings and is a Design-build, so that the systematic construction management from design to construction stage is more important for a successful project. This study introduces the practical tasks of construction management during the project and analyze some of main tasks to increase understanding construction management in the design-build project. Based on experience of construction management in this project, we examine managerial problems which frequently occur in this kind of project, and suggest how to improve construction management in Korea.

• Korean Journal of Construction Engineering and Management
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• v.10 no.5
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• pp.123-134
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• 2009

Since 1970s, urethane waterproofing method is broadly used in rooftops, underground spaces, and sports stadium for its outstanding ultraviolet blockage, watertightness, and elasticity. However, development of slippage-resistance and endurance, improvement of function considering convenience and visually pleasing of users, urethane waterproofing method is necessary, since rooftops and underground spaces have slippage and external force risks. Therefore, many improved waterproofing methods are being developed and, recently, embo-thane waterproofing method, which applies embo-spray coating system, has been developed. This paper explains exposure, nonexposure, and floor-material of embo-thane waterproofing method, and then perform experimental study for comparison with urethane waterproofing method about tensile strength, coefficient of expansion, performance of bond, anti-abrasion, and slippage-resistance. In addition, the performance index was presented for the superiority of embo-thane waterproofing method compared to urethane by setting up evaluation criteria considering not only physical performance but also design side of embo-thane waterproofing method, and Value Analysis applying AHP. Also for an assessment considering uncertain result, Monte Carlo Simulation Method was used to operate reliability analysis through statistic approach method.

• The KIPS Transactions:PartD
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• v.16D no.4
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• pp.517-526
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• 2009

It is possible to indicate the complex design and execution of object-oriented program with dynamic UML diagram. This paper shows the way how to make several test cases from sequence, state, and activity diagram among dynamic UML diagram. Three dynamic UML diagrams about withdrawal work of ATM simulation program are drawn. Then different test cases are created from these diagrams using previously described ways. To evaluate effectiveness of test cases, mutation testing is executed. Mutants are made from MuClipse plug-in tool based on Eclipse which supports many traditional and class mutation operators. Finally we've got the result of mutation testing and compare effectiveness of test cases, etc. Through this document, we've known some hints that how to choose the way of making test cases.

• Korean Journal of Construction Engineering and Management
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• v.22 no.2
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• pp.97-105
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• 2021

The CM at Risk project, which started with the aim of strengthening the global competitiveness of the domestic construction industry through innovation of ordering system, is being implemented in the form of pilot projects in the public sector. However, it seems that it is necessary to enact related laws and regulations to move to the formal ordering system, and the performance analysis of the project is still insufficient. In this paper, the effectiveness and reliability of the project were verified through the performance analysis of the Pre-Construction Service of the four pilot projects currently being implemented. The results of the study were analyzed in five areas including Team Building, Design Book, Construction Period, VE, and BIM. Through the interview survey, the problems were confirmed and improvement plans were presented. The results of this study are expected to be used as basic data for the legalization of ordering system to be implemented in the future.

• Korean Circulation Journal
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• v.53 no.9
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• pp.621-631
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• 2023

Background and Objectives: The morphology-voltage-P-wave duration (MVP) electrocardiography (ECG) risk score is a newly defined scoring system that has recently been used for atrial fibrillation (AF) prediction. The aim of this study was to evaluate the ability of the MVP ECG risk score to predict AF in patients with an implantable cardioverter defibrillator (ICD) and heart failure with reduced ejection fraction in long-term follow-up. Methods: The study used a single-center, and retrospective design. The study included 328 patients who underwent ICD implantation in our hospital between January 2010 and April 2021, diagnosed with heart failure. The patients were divided into low, intermediate and high-risk categories according to the MVP ECG risk scores. The long-term development of atrial fibrillation was compared among these 3 groups. Results: The low-risk group included 191 patients, the intermediate-risk group 114 patients, and the high-risk group 23 patients. The long-term AF development rate was 12.0% in the low-risk group, 21.9% in the intermediate risk group, and 78.3% in the high-risk group. Patients in the high-risk group were found to have 5.2 times higher rates of long-term AF occurrence compared to low-risk group. Conclusions: The MVP ECG risk score, which is an inexpensive, simple and easily accessible tool, was found to be a significant predictor of the development of AF in the long-term follow-up of patients with an ICD with heart failure with reduced ejection fraction. This risk score may be used to identify patients who require close follow-up for development and management of AF.