• Korean Journal of Computational Design and Engineering
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• v.13 no.2
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• pp.139-152
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• 2008

In order to survive worldwide competition, today's industries are experiencing strong pressure to introduce higher quality products with lower cost and shorter lead-time. Therefore, the role of design in the process of product development is increasing in significance. In this research, two methods for improving the design capability are proposed: construction of design environment and design automation using 3D CAD system. The designers and design process are the core of product design using 3D CAD system. In order to maximize the design performance, construction of the design environment including selection of a suitable system, designer training for best use of the system, establishment of an efficient design process, and stabilization of the environment are required. A method is suggested to construct design environment by systematizing the contents of the projects and consulting experiences carried out for various categories of business such as electronic devices, motorcycles, electricity parts, sanitary wares, injection molds, and die casing molds. Design automation helps reduce tedious and time-consuming jobs, simplify complicated and error-prone modeling and drawing works to shorten the lead time and improve the product quality. To develop a design automation system, understanding the process and the related knowledge on design are very important before implementing the system using API provided by 3D CAD system. In this research, an eight-step procedure is proposed for the development of a design automation system. These eight steps are analysis of needs, determination of specification, verification of specification using 3D CAD system, inspection of related API functions, programming, field test, application in practice, and maintenance. A case study in which five design automation systems in the design of turbine generators using the proposed method is introduced in detail. These systems play important roles in the generation of various output items including 3D models, drafts, material information, and NC data. The case study shows how effectively the design time is reduced and the quality improved using those systems.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.297-300
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• 2008

Since the Three Dimensional Computer Aided Design(3D CAD) appeared in 1990s, Building Information Modeling(BIM) has got the great issue in the construction project nowadays. BIM is the process of managing and generating building information during life cycle of a construction project. And information can be moved to 3D modeling flexibly in BIM. As a result, a field of estimating has also been doing researches in the calculation of the amount of building materials from 3D modeling. And the Construction Cost Estimating Software which is generally used over the world has been trying to be applied to the Construction project in Korea. But, when we consider the productivity, it is less efficient than the existing way in Korea which use the 2D Drawings when they take off the Quantity. Also, there are lots of difference how to estimate the construction cost. between Korea and the others. Because it is a bit hard to apply the software used in the other countries to the construction project in Korea, people couldn't use it well in the construction project actually. In this study, for developing the appropriate construction cost estimating software rooted in 3D in Korea, we suggest 3D CAD Add-on Program for a Quantity Take-off which can move quantitative information to 3D CAD.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.183-192
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• 2006

A CAD/CAM system has been developed for rapid prototyping (RP) of microfluidic devices based on excimer laser micromachining. The system comprises of two complementary softwares. One, the CAM tool, creates part programs from CAD models. The other, the Simulator Tool, uses a part program to generate the laser tool path and the 2D and 3D graphical representation of the machined microstructure. The CAM tool's algorithms use the 3D geometry of a microstructure, defined as an STL file exported from a CAD system, and process parameters (laser fluence, pulse repetition frequency, number of shots per area, wall angle), to automatically generate Numerical Control (NC) part programs for the machine controller. The performance of the system has been verified and demonstrated by machining a particle transportation device. The CAM tool simplifies part programming and replaces the tedious trial-and-error approach to creating programs. The simulator tool accepts manual or computer generated part programs, and displays the tool path and the machined structure. This enables error checking and editing of the program before machining, and development of programs for complex microstructures. Combined, the tools provide a user-friendly CAD/CAM system environment for rapid prototyping of microfluidic devices.

• Korean Journal of Computational Design and Engineering
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• v.21 no.2
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• pp.186-195
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• 2016

The finite element modeling of a ship for hull structural analysis on the basis of new harmonized common structural rules (CSR-H) is to be extended to the cargo holds in fore and after body of a ship. Unlike the parallel middle-body where the external and internal features of hull are equal along to the longitudinal direction of a ship, in fore and after body, the external and internal features of hull vary linearly or even irregularly in forms of a surface or a curve along to the longitudinal direction of a ship. Thus, it needs lots of design man-hours for the modeling for structural analysis. In order to save man-hours in initial structural design phase of a ship, the specified 3D CAD system has been adopted in shipbuilding industry. Through the interface between CAD and CAE (rule scantling and direct strength assessment), design man-hour in initial design phase can be saved even under the environment of CSR-H.

• Korean Journal of Construction Engineering and Management
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• v.9 no.3
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• pp.85-94
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• 2008

The process of construction industry basically consists of many complicated phase, such as planning, design, construction, MO&R(Maintenance, Operation, and Repair), and deconstruction. And various participants communicate each other during every phase of process. Since construction components have become more complex and diverse recently, many researches on how to exchange and standardization of building. However, in Korea research on IFC(Industry Foundation Classes) which is a standard for international data exchange have been conducted with only study limited Issues, such as studies on the development of 2D extension model for IFC, researches on 3D or 4D based IFC extension, and etc. This stuff covers tests of the compatibility among commercial 3D CAD programs using IFC file format. Several problems of the current IFC model are retrieved as a result.

• KIEAE Journal
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• v.10 no.4
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• pp.123-130
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• 2010

A lot of construction companies in overseas markets of construction try to change 2D CAD to 3D CAD for improving business ability and change to Building Information Modeling(BIM) for integrating information produced from construction life cycle. In America, GSA(General Service Administration) requires a design drawing planed by BIM and in Singapore and Europe, the government encourages architectures to use this tool. Recently in the domestic market, many organizations related construction industry are aware of importance of 3D CAD integrated information, and try to use BIM. Therefore, this research would analyze how does BIM affect construction industry and derive influence factors and provide basic data for using BIM.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1181-1186
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• 2005

In many construction projects, progress and efficiency are hampered by poor communication of discipline-specific models. For example, architects use 2D or 3D CAD models and builders use CPM diagrams, Gantt charts, and spreadsheets to show their view of the project. Nowadays, advanced computer visualization tools, 4D CAD or VR, can show these disparate models to understand cross-disciplinary impacts of design and construction decisions. In Korea, several leading companies have tried to apply these tools to their pilot projects from the design phase to the maintenance phase. These companies have expected that more project stakeholders could understand a construction schedule more quickly and completely with 4D visualization than with the traditional construction management tools. However, modeling of the 4D CAD or VR can be quite time-consuming and expensive to generate manually and has therefore limited the spread and use of these models. In order to adopt widely those models in construction industry, the areas that those tools could support to take large benefits in diverse functional areas of construction management need to be analyzed. In this study, researchers analyze the usefulness and limitations of the 4D models and VR in the construction industry, develop the strategy of application priority, and improve the 4D modeling method.

• Textile Coloration and Finishing
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• v.18 no.3 s.88
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• pp.49-58
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• 2006

The purpose of this study was to examine the effect of covering yarn's twist on mechanical properties of knitted fabrics of composite yarns with single covering process. Four yarns that were used in this study: two different composite yarns made from the four kinds of cotton and functional polyester-(Poly-A) with the ratio of 52:48, and the rest two yarns are the original cotton 100% yarn and the poly-A 100% yarn. The two kinds of composite yarns, CP1 and CP2, were processed on the single covering process. CP1 was applied on the single covering process with S-800 tpm, where Poly-A was used as covering yarn and cotton was used as core yarn. CP2 was applied on the same process as CP1 except that Poly-A had been applied on the two-for-one twisting process with S-400 tpm on the previous step. Sixteen mechanical properties of all the four knifed fabrics knitted under the same knitting conditions were measured by KES-FB system with the outer knit condition. And 3D CAD dressmaking simulations, which were driven by some of the mechanical properties, were presented. The results were as follows: CP2 had high RT values with twisting of covering yarn. CP2 also had high B, 2HB values because of higher linear density. SMD was affected rather by twisting of covering yarn than by fine hair of the cotton surface. Twisting of covering yarn made it decreasing T value and increasing W value. Dressmaking 3D CAD simulations showed that there are buckling effects on CP2 because of high bending rigidity and shear rigidity.

• The Journal of Advanced Prosthodontics
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• v.10 no.1
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• pp.50-57
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• 2018

PURPOSE. To investigate the effect of accelerated aging on surface properties of glazed CAD/CAM resin blocks using a 2D surface profilometer and a 3D non-contact optical profilometer. MATERIALS AND METHODS. Three types of CAD/CAM resin restorative materials, LAVA Ultimate (3M ESPE, St Paul, MN, USA), VITA Enamic (Vita Zahnfabrik H. Rauter, Bad $S\ddot{a}ckingen$, Germany), and Cerasmart (GC Corparation, Tokyo, Japan) were used for this study. CAD/CAM blocks were cut in 3-mm thickness slabs and divided into three groups; Group 1: control group (specimens polished with 600 grit SCI paper); Group 2: specimens sandblasted, silanized, and glazed with Optiglaze Color (GC); Group 3: glazed specimens subjected to 5000 thermocycles (n=15). The surface roughness ($R_a$ and $R_z$) was evaluated using a profilometer and a 3D scanning instrument. Data were analyzed using two-way ANOVA and Tukey's post- hoc test (P<.05). RESULTS. LAVA, VITA, and Cerasmart exhibited statistically similar $R_a$ and $R_z$ values for each group (P>.05). For VITA and Cerasmart, the specimens in Group 1 exhibited significantly higher $R_a$ values than Group 2 (P<.05). Group 1 ($0.502R_a$), Group 2 ($0.384R_a$), and Group 3 ($0.431R_a$) exhibited statistically similar $R_a$ values for LAVA (P=.062). After 5000 thermocycles, surface roughness values did not change significantly for glazed LAVA, VITA, and Cerasmart (P>.05). CONCLUSION. Glaze material Optiglaze Color makes CAD/CAM resin surfaces smooth and glazed CAD/CAM surfaces seem resistant to deterioration under 5000 thermocycles.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.290-295
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• 1989

This paper proposes a Expert CAPP System for integrating CAD/CAM of rotational work-part by rule based approach. The CAD/CAPP integration is performed by the recognition of machined features from the 2-D CAD data (IGES) file. Selecting functions of the process planning are performed in modularized rule base by forward chaining inference, and operation sequences are determined by means of heuristic search algorithm. For CAPP/CAM integration, post-processor generates NC code from route sheet file. This system coded in OPS5 and C language on PC/AT, and EMCO CNC lathe interfaced with PC through DNC and RS-232C.