• KIEAE Journal
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• v.16 no.1
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• pp.89-94
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• 2016

This study is part of three-dimensional(3D) heat transfer analysis program developmental process. The program is being developed without it's own built in 3D-modeller. So 3D-model must be created from another 3D-modeller such as generic CAD programs and imported to the developed program. After that, according to the 3D-geometric data form imported model, 3D-mesh created for numerical calculation. But the 3D-model created from another 3D-modeller is likely to have errors in it's geometric data such as mismatch of position between vertexes or surfaces. these errors make it difficult to create 3D-mesh for calculation. These errors are must be detected and cured in the pre-process before creating 3D-mesh. So, in this study four kinds of filters and functions are developed and tested. Firstly, 'vertex error filter' is developed for detecting and curing for position data errors between vertexes. Secondly, 'normal vector error filter' is developed for errors of surface's normal vector in 3D-model. Thirdly, 'intersection filter' is developed for extracting and creating intersection surface between adjacent objects. fourthly, 'polygon-line filter' is developed for indicating outlines of object in 3D-model. the developed filters and functions were tested on several shapes of 3D-models. and confirmed applicability. these developed filters and functions will be applied to the developed program and tested and modified continuously for less errors and more accuracy.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1581-1584
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• 2003

This paper proposed efficient manufacturing system using OMM(on-machine measurement) system and OMM operating S/W based 3D modeler. A Developed program connected tool machine with RS232C. It is composed two operating system that touch probe operating and laser displacement sensor operating system. A program for touch probe possible measure considered inspection feature and CAD data. The laser operating program is used inspection for profile. very small hole using installed feature data. This system is applied manufacturing line of mold(cavity, core) also verification of efficiency manufacturing process that production, reduction machining error of each process

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.3
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• pp.275-282
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• 1998

In this paper, we designed and fabricated 5-stage microwave solid state power amplifier using balanced amplifier scheme for X-band electronic radar reflector. The used substrate is FR4 and the used active devices are FHX35LC, FLK012WF and FLK022WG. The circuit design and optimization had been carried out through the microwave CAD program CNL2 The measured values show 46dB in gain, input return loss -14.2dB, output return loss -16.6dB and IM3 is 32dBc at designed bandwidth. The measured results are almost agreed with the simulated values.

• Journal of Computational Design and Engineering
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• v.1 no.3
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• pp.161-172
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• 2014

This paper presents three different search engines for the detection of CAD-parts in large databases. The analysis of the contained information is performed by the export of the data that is stored in the structure trees of the CAD-models. A preparation program generates one XML-file for every model, which in addition to including the data of the structure tree, also owns certain physical properties of each part. The first search engine is specializes in the discovery of standard parts, like screws or washers. The second program uses certain user input as search parameters, and therefore has the ability to perform personalized queries. The third one compares one given reference part with all parts in the database, and locates files that are identical, or similar to, the reference part. All approaches run automatically, and have the analysis of the structure tree in common. Files constructed with CATIA V5, and search engines written with Python have been used for the implementation. The paper also includes a short comparison of the advantages and disadvantages of each program, as well as a performance test.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.98-103
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• 2015

This study was conducted to analyze the running stability of a semi-crawler type mini-forwarder. The running stability analysis was performed by using a dynamic analysis program, RecurDyn. Physical properties of the semi-crawler type mini-forwarder was performed by using 3D CAD modeler, AutoCAD 3D. As a result from the computer simulation of stationary sideways overturning, it was found that the semi-crawler type mini-forwarder runs safely on a road with a slope not bigger than $20^{\circ}$ regardless whether it is empty or loaded, but in case of a road with a slope bigger than $20^{\circ}$, it is assumed that it is difficult for the car to run safely due to some dangers. In addition, it was found that the critical slope of its sideways overturning gets much smaller when empty since the location of its gravity center is elevated and much higher when it is loaded. As a result from the computer simulation of its hill-climbing ability, since the running speed is unstable in case of a road with a vertical slope not smaller than $28^{\circ}$, it is assumed that it is safe to drive it on a road with a slope not bigger than $28^{\circ}$. Taking a look at the result from an analysis of the running safety when it passes an obstacle, it was observed that a front tire comes off the ground when the running speed of the car is 5 and 4 km per hour respectively when it is empty and loaded while the gravity center of the front tire is watched. When taking a look at the changes in the location of the gravity center of the rear wheel crawler shaft, it was not found that the shaft comes off the ground at the test speeds both when it is empty and loaded.

• Korean Journal of Computational Design and Engineering
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• v.10 no.6
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• pp.381-391
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• 2005

The design methodology of injection molding die has been changed from two-dimensional drafting to three-dimensional solid modeling, which is due to many advantages over the conventional methodology in terms of design modification and data associativity. In addition to the solid modeling capability, it is required for a mold designer to utilize a database management system that facilitates efficient mold design. In the paper presented is the implementation of a software program which automatically generates three-dimensional mold-bases including standard parts and slider parts, conforming to given geometric constraints. It is based on a commercial CAD system (Unigraphics NX) along with related API (application program interface) libraries. The research is expected to reduce design efforts and simplify construction of a complex three-dimensional mold-base model that is comprised of standard parts and slider parts, by use of the three-dimensional database and automatized geometric dimensioning.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.3
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• pp.157-166
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• 2018

Purpose: This study was aimed to compare the consistency between the custom abutment design and the output in two CAD software programs. Materials and Methods: Customized abutments were designed by using 3Shape Dental System CAD software and Delta9 CAD software on a plaster model with implants (CRM STL file). After milling of the designed abutments, the abutments were scanned with a contact method scanner (Test STL file). We overlaid the Test STL file with each CRM STL file by using inspection software, and then compared the milling reproducibility by measuring the output error of the specimens from each CAD software program. Results: The Delta9 showed better milling reproducibility than 3Shape when comparing the milling errors obtained with a full scan of all specimens (P < .05) and also when comparing the axial wall region specifically according to the axial angle. With 0.9 mm marginal radius, the Delta9 showed better consistency between the design and the output than 3Shape (P < .05). While, anti-rotation form had no significant difference in error between the two systems. When cumulative errors were compared, the Delta9 showed better milling reproducibility in almost cases (P < .05). Conclusion: Delta9 showed a significantly smaller error for most of the abutment design options. This means that it is possible to facilitate generation of printouts with reliable reproducibility and high precision with respect to the planned design.

• Journal of the Ergonomics Society of Korea
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• v.24 no.2
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• pp.85-91
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• 2005

To understand the basic relationship between 3D curved surface model and 2D pattern, simplified torso model was generated by commercial CAD program (IDEAS). 3D torso model was then divided into different blocks and unfolded into a flat pattern as in ordinary works of clothing item design. As results, 2D pattern development of different part of 3D torso model was attempted and analyzed mathematically. It was found that different height, radius and tangent slope of 3D blocks resulted in different 2D pattern. The relationships between the shape parameters of 3D torso blocks and those of 2D patterns were analyzed using regression equations. Direct way of drawing a 2D pattern of corresponding 3D torso block was also illustrated for the convenience of pattern making using conventional measurements of upper/ lower radii and height of 3D torso block.

• Archives of design research
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• no.18
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• pp.25-34
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• 1996

Industrial design development methods and processes have changed in accordance with Industrial Information Age. These days, problems are created by existing methods and evaluation of design value , all problems concerned with time and finances sitaution have been made a subject of discussion. Development of design processes have been changed by the development of problem recognition and solving tools, and dpsign tpchnulugy havp hppn replaced by computer technology,Thus. software design processes linking thoughtware to hardware are used in the solution of design problems with many parts. In this study, 3D Modeling samples are presented, 3D Modeling can realise ' Ideas' to '3Dimentional Virtual Ohjects'. These effect and value are anle to decisively influence the process of design problem conference-ebealuation-solution.Proxesses of actual modeling and rendering are made as follows. By compusition of simple 20 drawings and shaping them into 30 objects, 30 solid models can be made. To prssent effectivley, we can make a sample model by varying camera views,light sourses,materials and colours etc. This sample is evaluated by various cumposition, methods and PERT(Program Evaluation and Review Technique). This cuncrete sample (tentative plan)is changed within the CAD SYSTEM by design evaluation, and then converted to flowchart of mass productive conception through refined data. So, that tentative plan can be conformed to design desire actuillly, to the utmost degree. Finally, this design process can be proposed as il new method in cuntrast with current methods. The aim of this study is to suggest effective evaluation methods of design outcome among many evaluating elements.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.2
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• pp.267-274
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• 2002

Using a flexible rotating beam test bed, experimental verification of a flexible multibody dynamic simulations for a rotating beam model has been carried out. The test bed consists of a flexible arm, harmonic driver reducer, AC servo motor and DSP board with PC. The mechanical ports of the test bed has been designed using 3D CAD program. For the simulation model, mass and moment of inertia of each part of the flexible rotating beam test bed are also obtained from 3D CAD model. In the flexible multibody dynamic simulations, the substructuring model has been established to capture nonlinear effects of the flexible rotating beam. Through the experimental verification, substructuring model provides better results than those from the linear model in the high speed rotation.