• Journal of the Society of Naval Architects of Korea
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• v.31 no.3
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• pp.1-11
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• 1994

The development of "Ship structural CAD system" has been performed in CSDP(Computerized Ship Design and Production) project to support ship structural design works. The procedures and contents of current design practice concerning the ship structural design were analyzed. To generate design information required at each design stage using the ship structural CAD system, the computerized model was created. To represent and implement the model information, a data structure which represents design concept as well as shape information was proposed using the concept of the product model. To embody the computerized model the object-oriented techniques were established to represent requirements of real world.

• Journal of the Semiconductor & Display Technology
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• v.17 no.1
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• pp.27-34
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• 2018

Industrially, die-casting products are formed through casting, and so the methods to inspect the defects inside them are very restrictive. External inspection methods including visual inspection, sampling judgment, etc. enables researchers to inspect possible external defects, but x-ray inspection equipment has been generally used to inspect internal ones. Recently, they have been also applying three-dimensional internal inspections using CT equipment. However, they have their own limitations in applying to the use of industrial inspection due to limited detection size and long calculation time. To overcome the above problems, this paper has suggested a method to inspect internal defects by comparing the CAD data of the product to be inspected with the 3D data of the CT image. In this paper, we proposed a method for fast and accurate inspection in three dimensions by applying x-ray inspection to find internal defects in industrial parts such as aluminum die casting products. To show the effectiveness of the proposed method, a series of experiments have been carried out.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.1
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• pp.29-39
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• 2006

Statements of problem: Zirconia core is used for posterior fixed partial dentures because it's good mechanical properties. Stress is concentrated on connectors in fixed partial dentures, so the proper design of connector areas is needed for adequate mechanical long-term properties of any prosthesis. The area of connector is critical, but tooth size and surrounding soft tissue limit the connector design. Purpose: The purpose of this study is to compare fracture strengths between different connector designs of zirconia core for posterior fixed partial dentures manufactured with CAD/CAM system and determining the optimal connector design satisfying strength and hygiene. Material and method: The following four groups of 40 posterior fixed partial denture specimens(each group 10) were fabricated as followed; group 1 vertical height of connector is 3mm (control group, all groups have the same condition); group 2, lingual vertical 1mm reinforcement on connector; group 3, lingual vertical 2mm reinforcing on connector and group 4, lingual vertical 3mm reinforcing on connector. Specimens were subjected to compressive loading on the central fossa of pontic by instron. SEM was used to identify the initial crack and characterize the fracture mode. Results: The results were as follows: 1. The mean fracture load of the non-lingual reinforcing group was 1212N and the lingual vertical 1mm reinforcing group was 1510N, the lingual vertical 2mm reinforcing group was 1882N, the lingual vertical 3mm reinforcing group was 1980N. 2. The reinforcing groups were statistically significant compared to non-reinforcing groups(P<0.001). 3. There were 2, 3mm reinforcing groups that were statistically significant compared to 1mm reinforcing groups(P<0.001), and the 3mm reinforcing group was not statistically significant compared to 2mm reinforcing groups(P>0.05) 4. Fractures were initiated in gingival embrasures of connectors and processed to the loading site. Conclusion: In this study, lingual reinforcement of connector for improved strength of zirconia based fixed partial denture is nessasary. And long-term study for clinical application is required

• Journal of the KSME
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• v.18 no.1
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• pp.28-33
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• 1978

이 설계점의 평가와 수정작업을 최적화라 한다. 최적화조작이 자동화되는 조건은 (1)설계점을 얻 는 것이 경험이나 직관에 의해서, 구하기가 어려울 겅우 (2) 설계점의 정량적 결정이 중요한 경우 (3)정량적 평가가 가능한 경우 최적화의 완전히 자동화 하기 위해서는 설계점에 대한 평가가 정 량화 되어야 한다. 예를 들면 외관등과 같은 미적요소가 덜어있는 것은 현재로서는 정량적평가가 불가능에 가깝다. 따라서 이 3개 조건 가운데서 특히 중요한 것은 (3)의 정량적 평가의 가부다. 이것이 불가능하거나 곤란할때는 최적화조작을 인간이 하여야하고 자동설계 system은 Man- Machine system이 된다. 이 대표적인 예가 CRT를 사용한 CAD system이다. 이에대해 설계점을 정량적으로 평가할 수 있을 때는 computer를 주체로한 system을 만들수 있고 이것을 AD ststem 에서는 계획적인 탐색법(최적화의 수법)을 쓴 수 있고 설계의 속도는 매우 빠르다. 그러나 이 system에서는 설계도중에 check가 힘들게 된다. CAD system에서는 설계점의 탐색이 시행착오적 이다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.28-32
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• 2013

In this study, we suggested new method for compensation on spring back of press part. At first, we compared between error on CAD data and scanning data. The new method can be substituted for manual modeling process in compensation on spring back. The new method is available for automatic modeling based on 3D scanning data. From the study, the results expect that time and cost reduction for process applying new method for compensation on spring back of press part.

• Journal of Korean Institute of Industrial Engineers
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• v.20 no.3
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• pp.35-53
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• 1994

Orthographic views ore traditionally used for engineering drawings. This paper presents a methodology for 3D parametric design using orthographic views. The parametric design technique, which is used to design 2D orthographic views, is based on production rules. In the production rule-base, several view interrelation rules and over 50 geometric rules are included. An efficient algorithm is also developed to expedite the reasoning process. For 3D object construction from orthographic views, the approach known as bottom-up geometrical approach is used. The approach consists of 4 steps : 1) generation of wire-frame, 2) construction of face from wire frame, 3) formation of 3D subobjects from faces, and 4) construction of final 3D objects. Curvilinear solids as well as planar solids can be constructed. A method of converting existing 2D CAD data to parametric 3D CAD data is also presented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.1
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• pp.233-240
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• 2000

We designed a 3D solid modeler based on the web, which was independent from platforms, which could be executed without 3D graphics softwares. In this paper, we show the design of system libraries and how to implement in Java 3D. A client connects to the solid modeler server, design solid model, stores the data as the various file format, and displays the data from other CAD systems. This solid modeler can support the detail design as 3D graphics features such as viewing, rendering, animating are available.

• Textile Coloration and Finishing
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• v.18 no.1
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• pp.33-43
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• 2006

The purpose of this study was to eximine the effect of different yam twisting methods on mechanical properties and 3D CAD images of plain knitted fabrics made of composite yarns. Six yams were used in this study: four different composite yams of the six consist of acetate and functional polyester (Poly-m) with the ratio of 70:30, and the rest two are the original acetate $100\%$ yam and the poly-m $100\%$ yarn. The four kinds of composite yarns were processed in combinations of twisting processes such as interlacing, false twisting, two for one twisting, combined twisting and single covering, and the two original yams were knitted without any twisting process. Sixteen mechanical properties of all the six knitted fabrics, knitted under the same knitting conditions, were measured by KES-FB system with the outer knit condition. The results were as follows; 1) When the sample applied with the false twisting process at the temperature as high as $220^{\circ}C$, ENT, B, HB, G and RC values of samples increased which leads to increasing dimensional stability. 2) To gain the high bending and shear properties in the single covering process, selecting the core yarn with such properties is the most important factor. 3) Interlacing process effected to increase RC value. 4) False twisting process after interlacing process gave bulkiness and un-interlaced part in yam was increased SMD value. The SMD value of the kilted fabric of the composite yarn, which was put through the combined twist process, was higher than those of which simple process such as the two for one twist or the single covering process applied. In order to achieve the silk-like surface feel of knitted fabric, the sin91e covering process is recommended. 5) Examining the simulation images of the knifed fabrics of composite yarn, which were generated by the 3D CAD system based on the mechanical properties of the fabric, led that appearance could be changed as different twisting methods were applied.

• Journal of The Korean Digital Architecture Interior Association
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• v.2 no.1
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• pp.9-15
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• 2002

As architectural forms tend to be large-scaled, high-storied and complicated, use of computer for processing design information has been generalized. However, CAD use in the process of developing architectural design has been neglected greatly in the educational field of architectural field due to the surging of recognition that it may limit the essential property of architectural design. It may be resulted from the limitation of CAD system, that is, it is because of tardy speed of application development for the related areas with the lack of simplicity and clarity of flexibility to be secured on the drawing and user interface. Recent CAD systems, however, overcome such a limitation, convert into object-based design from entity-based drawing, drafting and modeling for implementing design concept of architects and it connects with internet linked to superspeed information communication network and changes process and stream of architectural design. Therefore, this study deals with utility of object based CAD system with products of Autodesk Co. and consequently obtain the following conclusions. First, it expands architect's design areas by supporting cooperative design system based on model-based architectural design and internet. Second, it reduces consumption of personal and material resources and time in the process of drawing production for improving architectural design works. Third, it can reduce the frequent design changes by improving understanding of architectural space with visualization of immediate 3D information, escaping from traditional methods to deliver design information to building owner through 2D drawing or model and perspective drawing requiring much cost and time. Fourth, it keeps exactness without omission or duplication of design information and generate and renew information of all related drawings on a drawing. Fifth, it is possible to change difficult and boring architectural design work into a pleasure owing to immediate modeling and drawing of design idea. In addition, digital drawing generated by using object-based CAD system can playa role of establishing Urban Information System to be used for protecting from building in disaster and urban disasters in connection with GIS numerical map and be used for reference of all kinds of information required fro post-management of buildings. However, what is more important is that surplus time from introduction of object-based CAD system should be used for consideration to be recognized as a good space and building built as a product of this project for comfort to urban people.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.44.1-44.6
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• 2015

Background: The present study introduces the design and fabrication of a simple surgical guide with which to perform genioplasty. Methods: A three-dimensional reconstruction of the patient's cranio-maxilla region was built, with a dentofacial skeletal model, then derived from CT DICOM data. A surgical simulation was performed on the maxilla and mandible, using three-dimensional cephalometry. We then simulated a full genioplasty, in silico, using the three-dimensional (3D) model of the mandible, according to the final surgical treatment plan. The simulation allowed us to design a surgical guide for genioplasty, which was then computer-rendered and 3D-printed. The manufactured surgical device was ultimately used in an actual genioplasty to guide the osteotomy and to move the cut bone segment to the intended location. Results: We successfully performed the osteotomy, as planned during a genioplasty, using the computer-aided design and computer-aided manufacturing (CAD/CAM) surgical guide that we initially designed and tested using simulated surgery. Conclusions: The surgical guide that we developed proved to be a simple and practical tool with which to assist the surgeon in accurately cutting and removing bone segments, during a genioplasty surgery, as preoperatively planned during 3D surgical simulations.