• Journal of the Korean Society for Railway
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• v.4 no.4
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• pp.147-154
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• 2001

A high-speed rail system represents a typical example of large-scale multi-disciplinary systems, consisting of subsystems such as train, electrical hardware, electronics, control, information, communication, civil technology etc. The Systems Engineering, as a methodology for engineering and management of today's ever-growing complex system, must be applied to development of such systems. This paper presents systems engineering framework model to have to be applied to the systems engineering technology development task for the korean next-generation high-speed railway systems in progress and demonstrates data models and schema for computer-aided systems engineering software, RDD-100, for use in its development and management.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.7
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• pp.834-850
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• 2011

In this paper, a novel tissue engineering scaffold design method based on triply periodic minimal surface (TPMS) is proposed. After generating the hexahedral elements for a 3D anatomical shape using the distance field algorithm, the unit cell libraries composed of triply periodic minimal surfaces are mapped into the subdivided hexahedral elements using the shape function widely used in the finite element method. In addition, a heterogeneous implicit solid representation method is introduced to design a 3D (Three-dimensional) bio-mimetic scaffold for tissue engineering from a sequence of computed tomography (CT) medical image data. CT image of a human spine bone is used as the case study for designing a 3D bio-mimetic scaffold model from CT image data.

• Journal of the Korean Society of Systems Engineering
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• v.7 no.1
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• pp.53-56
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• 2011

Configuration management plays a key role in systems engineering process for any project from earlier stage of development. It consists of five major activities, ie., configuration management planing, configuration identification, configuration control, configuration status accounting and configuration verification and audit, and is essential to control system design, development and operation throughout entire life cycle of the system development. And it is directly associated with other part of systems engineering management process, ie., technical data management which provides traceability of important decisions and changes during development. In this paper, we describe how to apply CASE(Computer-aided Systems Engineering) tool-Cradle for the configuration management to achieve effectiveness of Technical Management process.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.12
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• pp.1085-1091
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• 2014

Recently, 3D printing has received increasing attention due to its boundless potentials. Because 3D printing starts from 3D geometry information, computer-aided design (CAD) is an essential technology to build 3D geometry data. These days, education of 3D CAD for engineering students has been changed from the theoretical lecture to practical design training using commercial CAD software. As a result, open-ended design projects have replaced the traditional theoretical examinations to evaluate students' outcomes. However, such design projects are not enough to evaluate students' outcomes because their results are expressed in two-dimensional ways. In this paper, applications of 3D printing in engineering design education are discussed by describing the procedure and outcomes of design projects. It was found that the use of 3D printing could improve students' outcomes by fabricating real physical models out of their designs.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.2
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• pp.145-151
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• 2015

In this paper, we proposed the fabrication methodology of orthotic device using 3D Computer-Aided Design programme and 3D printing technology based on images acquired from 3D scanner. We set the process and methodology of its fabrication method and confirmed whether it is available for clinical by fabricating four kinds of orthotic device for a patient with cerebral palsy. 3D printing technology method was indicated quantitatively and qualitatively about duration, tensile strength stronger comparing with conventional method, and we could propose that the 3D printing technology for the orthosis could be the proper method to mediate and compensate with reported problems related to orthosis.

• Journal of IKEEE
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• v.25 no.4
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• pp.778-781
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• 2021

In this paper, we propose the 16-layer 3D NAND Flash memory compact modeling using SPICE. In the same structure and simulation conditions, the channel potential about Down Coupling Phenomenon(DCP) and Natural Local Self Boosting (NLSB) were simulated and analyzed with Technology Computer Aided Design(TCAD) tool Atlas(Silvaco^TM) and SPICE, respectively. As a result, it was confirmed that the channel potential of TCAD and SPICE for the two phenomena were almost same. The SPICE can be checked the device structure intuitively by using netlist. Also, its simulation time is shorter than TCAD. Therefore, using SPICE can be expected to efficient research on 3D NAND Flash memory.

• The Journal of Advanced Prosthodontics
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• v.10 no.5
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• pp.335-339
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• 2018

PURPOSE. The purpose of the present study was to compare scanning trueness and precision between an abutment impression and a stone model according to dental computer-aided design/computer-aided manufacturing (CAD/CAM) evaluation standards. MATERIALS AND METHODS. To evaluate trueness, the abutment impression and stone model were scanned to obtain the first 3-dimensional (3-D) stereolithography (STL) file. Next, the abutment impression or stone model was removed from the scanner and re-fixed on the table; scanning was then repeated so that 11 files were obtained for each scan type. To evaluate precision, the abutment impression or stone model was scanned to obtain the first 3-D STL file. Without moving it, scanning was performed 10 more times, so that 11 files were obtained for each scan type. By superimposing the first scanned STL file onto the other STL files one by one, 10 color-difference maps and reports were obtained; i.e., 10 experimental scans per type. The independent t-test was used to compare root mean square (RMS) data between the groups (${\alpha}=.05$). RESULTS. The $RMS{\pm}SD$ values of scanning trueness of the abutment impression and stone model were $22.4{\pm}4.4$ and $17.4{\pm}3.5{\mu}m$, respectively (P<.012). The $RMS{\pm}SD$ values of scanning precision of the abutment impression and stone model were $16.4{\pm}2.9$ and $14.6{\pm}1.6{\mu}m$, respectively (P=.108). CONCLUSION. There was a significant difference in scanning trueness between the abutment impression and stone model, as evaluated according to dental CAD/CAM standards. However, all scans showed high trueness and precision.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.1
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• pp.87-92
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• 2016

In this paper, we improved classification performance of benign and malignant lung nodules by including the parenchyma features. For small pulmonary nodules (4-10mm) nodules, there are a limited number of CT data voxels within the solid tumor, making them difficult to process through traditional CAD(computer aided diagnosis) tools. Increasing feature extraction to include the surrounding parenchyma will increase the CT voxel set for analysis in these very small pulmonary nodule cases and likely improve diagnostic performance while keeping the CAD tool flexible to scanner model and parameters. In AdaBoost learning using naive Bayes and SVM weak classifier, a number of significant features were selected from 304 features. The results from the COPDGene test yielded an accuracy, sensitivity and specificity of 100%. Therefore proposed method can be used for the computer aided diagnosis effectively.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.1022-1027
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• 1989

CAD drawings contain drawing errors similar to manually produced drawings. This paper is concerned with a computer-aided drawing check system for the drawing errors. The problem treated in this paper is the checking of dimension errors, deficiency and redundancy of dimension lines in the mechanical drawings made by a CAD system. Graph theory is used for the checking of the deficient and redundant dimensions. The feasibility of this system is confirmed for the checking items.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.7
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• pp.116-124
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• 2002

The planning of part feeder and other manufacturing automation equipments is almost always underestimated. Planning ahead for those crucial pitfalls can permit steps to take to minimize heir impacts, especially if the problems can be discovered in the planning phase, not on the shop floor. Planning process is an engineering process, namely a series of trade-offs. The effective trade-offs in the shortest amount of time can be possible with the help of a computer-aided ngineering (CAE) technique. The main parts of CAE fur part feeder are database system of fabricated workpiece parts, part feeders, part feeder components. In this study, a planning process of part feeder is presented. Especially, a systematic analysis of workpiece parts and part feeders is performed for the design of databases of CAE system.