• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.471-474
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• 2004

In this paper, a NURBS surface interpolator is proposed which can deal with shapes defined from CAD/CAM programs on a surface basis and can improve contour accuracy. The proposed interpolator is based on newly defined G-codes and includes online tool-path planning suitable for NURBS surface machining. The real-time interpolation algorithm, considering an effective machining method for each machining process and minimum machining time, is executed in an online manner. The proposed interpolator is implemented on a PC-based 3-axis CNC milling system and evaluated through actual machining in terms of machining time and regulation of feedrate and cutting force in comparison with the existing method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.04b
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• pp.267-271
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• 1993

Developed in this paper is a feature based modeling of welded plate construction(WPC) which is composed of flat or bended plates represented as reference plane with a constant thickness. First, the necessity and the characteristics of the feature based modeling of WPC as compared with the assemblies of mechanical parts are investigated. Second, feature library for the assemblied of WPC is shown which contains several types of features like joint feature, groove feature, materialfeature and precision feature. Third, the assembly procedures are presented whichmainly consist of both the assembly transformation and the correct assembly checking. Fourth, weld lines generated in the assembled WPC are defined so that those can be used in the process planning or the manufacturing stage. Finally, A prototype system isdeveloped by using a geometric modeling software Pro/Engineer, a graphic software GL(Graphic Library), and C language on a CAD workstation IRIS.

• Korean Journal of Computational Design and Engineering
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• v.5 no.1
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• pp.79-87
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• 2000

This paper presents an integrated but open product development environment for distributed and collaborative design. The web-based framework, called DOME, allows designers to build integrated models using both local and distributed resources, and to collaborate by exchanging services in a network-centric product development environment. Thus, an integrated model can be created while each participant focuses on his or her own area of expertise. A design problem model is created by connecting modules, which represent specific system components, analysis capabilities/software, disciplines, or organizations relevant to the problem. The modules interact with each other using service exchanges based upon the CORBA standard communication protocol. The goal of this framework is tall provide the ability to rapidly construct integrated design problem models to facilitate collaborative design work, improve product quality and reduce development time. Ultimately, it should allow specialized engineering applications and design problem models to operate under a common design environment.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.11a
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• pp.79-87
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• 2002

An attempt to automate the surface finishing process of the die and mould has been carried out. An UMB(Ultrasonic Micro Burnishing) equipment which brought the micro plastic cold deformation to the 3D sculptured surface of mold and dies by ultrasonic vibration and static load, was developed and installed at the head stock of a vertical machining center. To be satisfied with the required surface roughness and hardness, the DB based program was also developed and applied. This equipment composes of UMB equipement, CNC vertical machining center, CAD/CAM system and the DB based program fer optimal condition. UMB processing effect was obtained from initial value Ral.25 and Hk337 to Ra0.085 and Hk521 and similar result was shown in industrial mould application.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1995.03a
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• pp.162-169
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• 1995

An improved nonparametric tool description based on successive refined monparametric patches is proposed and therlated criterion for refinement is also discussed . In the proposed sheme, any required order of tool surface conformity can be achieved by employing successive refinements accoring to the suggested criterion. By using the suggested adaptive tool refinement technique based on the nonparametric patch tool description, the locally refined nonparametric tool surface with economic memory size and sufficient accuracy as well as with favorable charateristics for contact treatment can be obtained directly form the parametric patch related with commerical CAD system. Computation is carried out for a chosen complex sheet forming example of an actual autobody panel in order to verify the validity and the efficiency of the developed tool surface description.

• International Journal of Costume and Fashion
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• v.15 no.2
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• pp.63-77
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• 2015

By means of statistical analysis and module concept, this paper investigated the current situation of high school girl's uniform and put forward its improved design and database establishment. Combined with the survey data, the future design direction and trend of the high school girls' uniform were proposed. By using modular design concept, the uniform is divided into five modules, and a style database has been built. Meanwhile, the parametric pattern database has been completed by using garment CAD system, based on the style database above, which has 42,336 possibilities to assemble a pair of school uniform. Combining with digital sewing techniques and by using computerized embroidery machine, the personalized design of high school girl's summer uniform has been realized. And two simulated case have been given for examples to prove its feasibility. The idea of modular design and parametric design method proposed in this study offer references for establishing the modular design database and parametric pattern database for other types of school uniform and are of relatively high practical and theoretical value.

• Korean Journal of Computational Design and Engineering
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• v.12 no.4
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• pp.245-254
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• 2007

This research proposed feature extraction algorithms as an input of STEP Ap214 data, and feature parameterization process to simplify further design change and maintenance. The procedure starts with suppression of blend faces of an input solid model to generate its simplified model, where both constant and variable-radius blends are considered. Most existing cell decomposition algorithms utilize concave edges, and they usually require complex procedures and computing time in recomposing the cells. The proposed algorithm using reference features, however, was found to be more efficient through testing with a few sample cases. In addition, the algorithm is able to recognize depression features, which is another strong point compared to the existing cell decomposition approaches. The proposed algorithm was implemented on a commercial CAD system and tested with selected industrial product models, along with parameterization of recognized features for further design change.

• International Journal of Naval Architecture and Ocean Engineering
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• v.2 no.2
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• pp.96-103
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• 2010

A concept of preliminary design for mid-size superyachts is explored. First, the profile of a superyacht is interactively designed with the help of freeform curve functionality and graphical user interface (GUI) based interaction. The hull form is then constructed using major characteristic curves such as design waterline, deck sideline, and sections in addition to the predefined profile curve. After exterior hull modeling is done, the arrangement of significant interior spaces of all decks is carried out. A genetic algorithm is exploited to find a space arrangement by considering space fitness values, space proximity, and stairs connectivity of relevant spaces. A goal of the paper is to offer a step-by-step procedure for superyacht design from scratch or when initial information is not sufficient for complete design. For this purpose, a GUI based superyacht design system is developed. This design approach is expected to help users interactively design mid-size superyachts.

• Transactions of Materials Processing
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• v.5 no.1
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• pp.47-54
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• 1996

An improved nonparametric tool description based on successive refined nonparametric patches is proposed and the related criterion for refinement is also discussed. In the proposed scheme any required order of tool surface conformity can be achieved by employing successive refinements according to the suggested criterion. By using the suggested adaptive tool refinement technique based on the nonparametric patch tool description the locally refined nonparametric tool surface with economic memory size and sufficient accuracy as well as with favorable characteristics for contact treatment can be obtained directly from the parametric patch related with commercial CAD system. Computation is carried out for a chosen complex sheet forming example of an actual autobody panel in order to verify the validity and the efficiency of the developed tool surface description.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.10a
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• pp.429-436
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• 2003

A new linkage framework between elastic shell element with finite rotation and computar-aided geometric design (CAGD) (or surface is developed in the present study. The framework of shell finite element is based on the generalized curved two-parametric coordinate system. To represent free-form surface, cubic B-spline tensor-product functions are used. Thus the present finite element can be directly linked into the geometric modeling produced by surface generation tool in CAD software. The efficiency and accuracy of the Previously developed linear elements hold for the nonlinear element with finite rotations. To handle the finite rotation behavior of shells, exponential mapping in the SO(3) group is employed to allow the large incremental step size. The integrated frameworks of shell geometric design and nonlinear computational analysis can serve as an efficient tool in shape and topological design of surfaces with large deformations.