• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.8
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• pp.911-916
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• 2014

The leisure boat industry has the potential to become a high-value-added industry in the future. Recently, a study on Korean high-speed leisure boats for fishing was conducted. This study suggests a product configuration model-based shipbuilding cost estimation method for determining the type of leisure boat suitable for mass production, as part of a research for productivity improvement. The suggested estimation method based on the analysis of the leisure boat process and generic YWBS can calculate quantitative and concrete data. By using this method, the cost of building the catamaran-type design ship can be reduced by 17 times, compared to that of the monohull-type mother ship. This implies that the final design of the Korean high-speed leisure boat for fishing will have a competitive price at the actual production stage.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1606-1611
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• 2008

Recently, The diagnosis techniques of electric facilities are developed on live line. This paper describes the discharge characteristics of polymer insulator(EPDM A type). Keeping the facilities in good working order, the goal of this paper will provide the information to enable user to easily judge conditions of facilities on the spot. The performance of polymer insulator is assessed from the KS C IEC 60270 and CEA LWIWG-01(96)(Tracking Wheel Test). As the results, UV generation patterns of polymer insulator grow like a jellyfish shape follow the ramping voltage. Discharging UVs are detected at about 31.25% of breakdown voltage. Just then, dimension of UV image is about $0.84cm^{2}$. The dimension of max. UV image is about $297.4cm^{2}$ at $160kV(V_{bd})$. The position of UV generation due to surface discharge of polymer insulator is the center of insulator in the early, then moved the ground side and the last, UV image moved through the junction part of source side. Surface of aged polymer insulator is cracked and faded due to arc. UV absorption spectrum of polymer insulator are appeared the C-H bond of scissoring vib. at $1014cm^{-1}$ and C=O bond of recombination structure. Also, recombined UV absorption peak such as C-H, N-H, and O-H is detected at the $3321cm^{-1}$. Through the paper, there are inspection data which are the relations between surface discharge of polymer insulator and UV detecting image.

• Korean Journal of Construction Engineering and Management
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• v.6 no.1 s.23
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• pp.177-185
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• 2005

The purpose of this study is to develop a supporting tool for efficient management, at preconstruction phase, of the schedule risk that is able to generate at construction phase. The main contents of this study to develop a practical tool are as follows. First steel work was selected as a relevant trade and a risk breakdown structure focused on the process of steel work having large effect on total construction process was made. Secondly, the work flow considering schedule risk factor was made and schedule risks that must be managed preferentially through analyzing the grade of importance for risk was selected. Finally, based on above two procedure, the management form for schedule risk was developed It is necessary to accumulate abundant data for schedule risk for other construction process and to develop a manual and a schedule risk management system.

• Korean Journal of Construction Engineering and Management
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• v.11 no.1
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• pp.160-169
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• 2010

In domestic public works, there are several problems in the measurement of payments based on the bill of quantity, which doesn't match with the activity progress rate, heavy paper works and complicated procedures. It can be classified formal and simplified method. By using the simplified method, it can be solved many problems by summarizing the procedure, but is not generally used. This paper proposes a payment method by progress measurement for specified activity based on WBS(Work Breakdown Structure) verifying efficiency which reduced cost account and advanced work on payment compare to method of domestic public works using the data about construction of eco-river. This method will be an important contribution on being a base for cost-schedule integrated management which were verified and also improving efficiency on measuring payment.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.1
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• pp.1-7
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• 2014

A bidirectional transient voltage suppression (TVS) diode consisting of specially designed $p^--n^{{+}+}-p^-$ multi-junctions was developed using low temperature (LT) epitaxy and fabrication processes. Its electrostatic discharge (ESD) performance was investigated using I-V, C-V, and various ESD tests including the human body model (HBM), machine model (MM) and IEC 61000-4-2 (IEC) analysis. The symmetrical structure with very sharp and uniform bidirectional multi-junctions yields good symmetrical I-V behavior over a wide range of operating temperature of 300 K-450 K and low capacitance as 6.9 pF at 1 MHz. In addition, a very thin and heavily doped $n^{{+}+}$ layer enabled I-V curves steep rise after breakdown without snapback phenomenon, then resulted in small dynamic resistance as $0.2{\Omega}$, and leakage current completely suppressed down to pA. Manufactured bidirectional TVS diodes were capable of withstanding ${\pm}4.0$ kV of MM and ${\pm}14$ kV of IEC, and exceeding ${\pm}8$ kV of HBM, while maintaining reliable I-V characteristics. Such an excellent ESD performance of low capacitance and dynamic resistance is attributed to the abruptness and very unique profiles designed very precisely in $p^--n^{{+}+}-p^-$ multi-junctions.

• Journal of Software Engineering Society
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• v.26 no.4
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• pp.77-92
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• 2013

To plan a software project, the manager (1)make a work breakdown structure (WBS), (2) estimate efforts for each task, (3) assign employee to each task, and (4) estimate overall schedule. When software project becomes complicated, the possible combination of WBS, effort, and employee assignments dramatically becomes larger. Software planning tool can help software project managers to deal with this complexity. In this research, we discuss with a group of experts who work in software industry, to elicit practical requirements that should be considered in the software planning technique. Considering these requirements, we develop a software project planning tool APP (Automatic Project Planner) which provide effort estimation based on historical knowledge data and automatic human resource allocation. Our technique can be the basis of reasonable and practical software project planing.

• Journal of KIBIM
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• v.8 no.4
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• pp.49-59
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• 2018

Recently, the application of BIM for port & harbour facilities has been increasing, as it is widely applied to the infrastructure field both at domestic and abroad. However, the port and harbour projects still have very poor facilities information management system and the application level of BIM is very low compared to other facilities. Even if BIM is applied for those project, it is very difficult to determine in advance what information is needed without an accurate understanding of the business process. The purpose of this study is to develop a BIM framework for port & harbour facilities and to examine its applicability. To do this, we structured the classification of the port & harbour facilities and constructed object-based classification system based on ISO12006-3 standard. We also derived the BIM framework requirements from the viewpoint of process, standard, interface, and information, and confirmed the linkage of the BIM object classification system in the framework item. The applicability of the BIM framework for inspection process cases of port & harbour was examined. Accordingly, this study can solve requirement setting method, which is the non - procedural and non - systematic project information, in the BIM application process of the port & harbour project with the BIM framework. In addition, the framework is expected to be integrated into the system to play a key role in the selection of project objectives, and the ability to clearly identify the information requirements required by the BIM manager to perform the project.

• Korean Journal of Construction Engineering and Management
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• v.17 no.2
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• pp.99-109
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• 2016

The utilization of Building Information Modeling (BIM) has increased in order to enhance the integration of information for management and resources throughout the construction projects. Therefore, various BIM softwares have been used under open BIM environments in the building and plant construction industry. However, it has obstructive factors due to the lack of interoperability. In order to address this problem, this study conducted an interoperability analysis of BIM software focused on user-defined properties for enhanced function and efficiency. Result of the analysis shows that authoring tools have more interoperability problems than viewer tools and simulation tools have. In terms of interoperability, user-defined properties outperforms than those of system basic properties and logic data. Therefore, it was found that functional improvement and workload minimization in BIM can be attained by applying the GBS (an user-defined property for automatic manipulation of BIM proposed by Jung et al. 2013) that enables automatic link between geometric data and non-geometric data. In this respect, this study concludes that the application of user-defined property (e.g. GBS) can be an effective method for information integration throughout construction projects.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.173-173
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• 2010

$Bi_4Ti_3O_{12}$ ($B_4T_3$) is a unique ferroelectric material that has a relatively high dielectric constant, high Curie temperature, high breakdown strength, and large spontaneous polarization. As a result this material has been widely studied for many applications, including nonvolatile ferroelectric random memories, microelectronic mechanical systems, and nonlinear-optical devices. Several reports have appeared on the use of Mn dopants to improve the electrical properties of $B_4T_3$ thin films. Mn ions have frequently been used for this purpose in thin films and multilayer capacitors in situations where intrinsic oxygen vacancies are the major defects. However, no systematic study of the optical properties of $B_4T_3$ films has appeared to date. Here, we report optical data for these films, determined by spectroscopic ellipsometry (SE). We also report the effects of thermal annealing and Mn doping on the optical properties. The SE data were analyzed using a multilayer model that is consistent with the original sample structure, specifically surface roughness/$B_4T_3$ film/Pt/Ti/$SiO_2$/c-Si). The data are well described by the Tauc-Lorentz dispersion function, which can therefore be used to model the optical properties of these materials. Parameters for reconstructing the dielectric functions of these films are also reported. The SE data show that thermal annealing crystallizes $B_4T_3$ films, as confirmed by the appearance of $B_4T_3$ peaks in X-ray diffraction patterns. The bandgap of $B_4T_3$ red-shifts with increasing Mn concentration. We interpret this as evidence of the existence deep levels generated by the Mn transition-metal d states. These results will be useful in a number of contexts, including more detailed studies of the optical properties of these materials for engineering high-speed devices.

• Journal of the Korea Institute of Building Construction
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• v.11 no.6
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• pp.567-575
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• 2011

With the development of construction information, a computerization tool for architectural process control is a necessary tool. However, the reality is that the conditions and understanding of users are not sufficient to fully utilize such a tool. In particular, it was analyzed that the reason for the negative feedback from hands-on workers regarding the current process control information system is that there is a difficulty in accessing the system for users that are not process and planning experts, due to a lack of information and technical contents at the phase of control and planning prior to the process plan. Therefore, the demands of users and a direction for the improvement of a system in terms of optimizing process control computerization were investigated, with the aim of addressing the disadvantages of the existing system and developing a professional system that is specialized in the construction industry. Therefore, it is necessary to construct an integrated WBS (IWBS) that combines WBS with CBS, and subsequently, it is judged that the most important aspect is the integrated technology of compatibility and operation of data that is linked with OBS. The process information must then deal with the changing information; in other words, the amount of construction, construction cost, and the required construction period etc., by coding data into a 4-unit index, such as a project unit (WBS Level 1), a project facility unit (WBS Level 2), a management department unit (OBS Level 1), and a control manager unit (OBS Level 2). After that, it was found that it is necessary to develop a computer system to consistently integrate process information into a management department.