• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.224-230
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• 2005

In order to realize a three-dimensional shape on CAD, the machining process has been widely used because it offers practical advantages such as precision and versatility. However, the traditional machining process needs a large amount of time in cutting a product and the remained material causes trouble such as inconvenience due to cleaning process. This paper introduces a new rapid manufacturing process called Rapid Heat Ablation process (RHA) using the rotary hot tool to overcome limitations of traditional machining process. The rotary hot tool to satisfy requirements of RHA process is designed and produced. In order to examine relationships between kerfwidth and process parameters such as heat input, speed of tool and speed of revolution, experiments were carried out. In addition, relationship between the kerfwidth and the effective heat input was obtained. Based on the experimental results, double-curved shape was ablated to show the validity of proposed process. In the procedure, the rough cut and fine cut were performed according to the conditions of process parameters without tool change process. The practicality and effectiveness of the proposed process have been verified through ablation of three-dimensional shape.

• Journal of Biomedical Engineering Research
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• v.27 no.5
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• pp.291-299
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• 2006

A Computer-Aided Diagnosis system has been examined to reduce the effort of radiologist. In this paper, we propose the algorithm using Support Vector Machine(SVM) classifier to discriminate whether microcalcifications are malignant or benign tumors. The proposed method to detect microcalcifications is composed of two detection steps each of which uses SVM classifier. The coarse detection step finds out pixels considered high contrasts comparing with neighboring pixels. Then, Region of Interest(ROI) is generated based on microcalcification characteristics. The fine detection step determines whether the found ROIs are microcalcifications or not by merging potential regions using obtained ROIs and SVM classifier. The proposed method is specified on Korean mammogram database. The experimental result of the proposed algorithm presents robustness in detecting microcalcifications than the previous method using Artificial Neural Network as classifier even when using small training data.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10a
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• pp.218-222
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• 2006

최근 산업현장에서는 작업의 빈번한 변화에 따른 로봇의 재배치, 테스트로 인해 많은 비용이 소모되고 있다. 이러한 문제점의 해결방안으로 OLP(Off-line Programming) 시뮬레이션 시스템이 주목받고 있다. 현재 대부분의 OLP 시뮬레이션 시스템은 하나의 컴퓨터에서 실행되는 하나의 응용프로그램으로 되어있다. 따라서 로봇을 제어하는 시뮬레이션 프로그램이 복잡해지고 시뮬레이션 대상이 되는 작업장의 규모가 커지게 되면 이와 비례하여 시뮬레이션에 소모되는 시간이 늘어나게 되고 이로 인하여 시뮬레이션 진행상황을 실시간에 맞추어 출력하지 못하게 되는 경우가 발생하게 된다. 또한 하나 컴퓨터에서 실행되는 응용 프로그램의 한계로 인해 시뮬레이션 상황을 출력하는 화면크기는 제한될 수밖에 없어지고 여러 작업장의 시뮬레이션 진행상황을 동시에 확인하기가 힘들어 진다. 본 논문에서는 이러한 문제점을 해결하기 위하여 하나의 PC에서 실행되는 OLP 시뮬레이션 시스템을 사용자가 지정하는 로봇의 집합 단위로 네트워크로 연결된 여러 개의 PC에서 실행할 수 있도록 하여 다수의 로봇 제어 프로그램을 실행하는데 걸리는 부하와 시뮬레이션 진행 상황을 출력하는 CAD시스템에 걸리는 부하를 분산 시키고 연결된 여러 PC를 통해 시뮬레이션 진행상황을 자유롭게 확인할 수 있는 구조를 제안하였다. 그리고 시뮬레이션 시스템의 분산화로 인해 발생하는 동기화 문제에 대한 해결 방안으로 기존 시스템에 사용되는 이벤트/사이클 혼합 방식의 로봇 시뮬레이션 시스템의 알고리즘을 분산시킨 방안을 제시하였다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.8
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• pp.91-97
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• 2019

A method for generating 3D solid models and drawings for a rotor in the steam turbine is proposed. One of the most important design steps is generating the drawing for manufacturing it. This step is a very routine and time-consuming job because each drawing is composed of several kinds of views and many dimensions. To achieve automation for this activity, rotor profiles are composed of 2D entity groups with attributes. Based on this, the improved design process is developed as follows. First, the rotor profiles can be selected by searching for 2D entity groups using the related attributes. Second, the profiles are connected sequentially so that an entire rotor profile is determined. The completed profile is used to generate 2D drawings automatically, especially views, dimensions, and 3D models. The proposed method is implemented using a commercial CAD/CAM system, Unigraphics, and API functions written in C-language and applied to the rotor of steam turbines. Some illustrative examples are provided to show the effectiveness of the proposed method.

• Transactions of Materials Processing
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• v.32 no.6
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• pp.360-366
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• 2023

This study is concerned with the surface quality of products according to the material and coating condition of the forming tool in incremental sheet forming. Three forming tools, SKD11 with and without diamond-like-coating (DLC) and polymer tool tip, were used to form conical and pyramidal geometries to take into account the influence of friction between the forming tool and the sheet on the surface quality including geometric accuracy of deformed samples. Each test was performed using SUS304 with a thickness of 0.4 mm according to different incremental depths per lap of 0.5 mm, 1.0 mm, and 1.5 mm for the contour tool path, considering the increase in normal force which is associated with the frictional behavior during local deformation. The surface quality was then investigated through surface roughness measured with KEYENCE VR-6000 and relative strain distribution including deformed shape analyzed with ARGUS which is a non-contact optical strain measurement system. Differences between 3D CAD surfaces and captured geometry from experiments were evaluated to compare the effect of friction on geometric accuracy. From comparisons of experimental results, it was revealed that the polymer-based tool tip can improve surface quality and geometric accuracy by reducing the undesired material flow due to local friction in the increment sheet forming process.

• The Journal of Information Technology
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• v.5 no.3
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• pp.197-214
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• 2002

Electronic Commerce has already existed for over 20 years. The Bolero project initially had the support of TEDIS, and now is jointly financed by SWIFT(Society for World International Financial Telecommunications) which handles most of the electronic funds transfer for banks, and the Through Transport Mutual Assurance Association(the TT Club), a mutual insurance association most of whose members are drawn from the Multimodal transport industry or transport intermediaries. Bolero's mission is to provide guaranteed and secure delivery, in electronic form, of trade documentation, globally, based on a binding legal environment and common procedures, Bolero will also provide a platform for provision of neutral cross-industry services. TradeCard is a payment and settlement system that is an alternative to letters of credit. That is, TradeCard is a business-to-business e-commerce infrastructure that enables buyers and sellers to conduct and settle international trade transactions securely over the Internet. Paperless, payment-guaranteed international trade transactions - which eliminate the traditional letters of credit with electronic certifications - are widely considered the most difficult B2B transactions to conduct.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.4
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• pp.723-729
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• 2001

We are able to work on the shared virtual space in Web-based Collaborative Design System using only Internet and Web browser. The users connect to the Solid Modeler Server through m and they create 3D shape and manipulate them variously. Then the users will share 3D objects and two problems can arise. The users must be able to pick the objects effectively which they want to manipulate. When one of the users manipulates a particular object, others should not disturb with the same object. In this paper, picking is implemented not only by computing intersection of mouse pointer with the objects of the virtual world, but also by using capabilities and attributes of scene graph node, by setting bounds intersection testing instead of geometric intersection testing, by limiting the scope of the pick testing, using Java 3D. These methods can reduce the computation of picking and can pick 3D objects effectively and easily using the system of hierarchy. To have effective concurrency, we used shared lock and exclusive lock as the action in work space.

• Design Convergence Study
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• v.15 no.2
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• pp.169-184
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• 2016

Using geospatial information in the early design phase is crucial because it requires considerable time, money, and effort. We use VWorld, part of the National Spatial Information Distribution system provided by the Korean Ministry of Land, Infrastructure and Transportation, for providing geospatial information to building designers. We provide methods to adopt VWorld geospatial information to building design and develop plugins for a BIM authoring tool to transform and construct necessary BIM data in a user-friendly format. BIM users are benefitted from extra design information supplied from sibling disciplines such as urban design. GIS users are benefited by feedback building information continuously supplied from building projects based upon standard GIS coordinates. It is clear that an architectural designer with BIM tool can save time and efforts to obtain the geospatial information related a project using the developed system as result of this research.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.252-259
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• 2013

Building Information Modeling (BIM) is utilizing CAD technology in a way that ultimately ties all the components of a building together as objects imbedded with information, and has been changing the way we design and build over the last 20-30 years. In Polytechnic Institute of NYU, there are four BIM courses offered which provide students with different levels of knowledge regarding BIM Technique, BIM Standards, BIM Guideline and Roadmap for Private and Public Implementation, BIM Application in Real Projects, the Cooperation of BIM and IPD for Public Works in New York City. With advanced BIM technology, BIM's integration into the construction process and its incorporation into project delivery systems, especially Integrated Project Delivery (IPD) are the bridges between technology, industry and research. This paper presents an integrated BIM curriculum with three modules: 1) BIM functions and Bid Preparation; 2) Time-Cost Trade-off Analysis; and 3) Problems Solving in BIM/IPD Environment. In this project-based curriculum developed by the common efforts of academia, public agency and industry, the objectives are: (1) to provide the information and skills needed to successfully implement BIM into the construction phase; (2) to identify BIM's role in construction and the project delivery system; (3) to develop a module in conjunction with leading BIM into project delivery system, particularly coordination between BIM and IPD; (4) to connect technology and research into industry. The course assessment was conducted and the results indicate that it is a successful reform in construction management education.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.4
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• pp.319-327
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• 2010

A nuclear plant ESF ACS simulator was designed, built, and verified to perform experiment related to ESF ACS of nuclear power plants. The dimension of 3D CAD model was based on drawings of the main control room(MCR) of Yonggwang units 5 and 6. The CFD analysis was performed based on the measurement of the actual flow rate of ESF ACS. The air flowing in ACS was assumed to have $30^{\circ}C$ and uniform flow. The flow rate across the HEPA filter was estimated to be 1.83 m/s based on the MCR ACS flow rate of 12,986 CFM and HEPA filter area of 9 filters having effective area of $610{\times}610mm^2$ each. When MCR ACS was modeled, air flow blocking filter frames were considered for better simulation of the real ACS. In CFD analysis, the air flow rate in the lower part of the active carbon adsorber was simulated separately at higher than 7 m/s to reflect the measured value of 8 m/s. Through the CFD analyses of the ACSes of fuel building emergency ventilation system, emergency core cooling system equipment room ventilation cleanup system, it was confirmed that all three EFS ACSes can be simulated by controlling the flow rate of the simulator. After the CFD analysis, the simulator was built in nuclear grade and its reliability was verified through air flow distribution tests before it was used in main tests. The verification result showed that distribution of the internal flow was uniform except near the filter frames when medium filter was installed. The simulator was used in the tests to confirm the revised contents in Reg. Guide 1.52 (Rev. 3).