• Journal of The Korean Digital Architecture Interior Association
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• v.1 no.1
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• pp.46-50
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• 2001

It is known that to automate the quantity take-off process enables you to increase the productivity best among the construction business field. However, the limitation of 2D(Two-dimension) CAD System prevented a cost-estimating system which makes the great effects on the quantity take-off process from being developed. This study aims that you can automate both the itemized statements and the quantity take-off process by using commercially available object-oriented CAD system. The commercially available CAD system today does not give us entire satisfaction. This study shows the deduction of the old boundaries of the object-oriented CAD system and the solution of those problems. And it also studied about the quantity take-off process and the automated cost-estimating system that can be used in the simple and plain repair-maintenance work such as the execution drawing which doesn't need the complicated drawings.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.5
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• pp.57-70
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• 2009

A CAD design drawing based on vector data that is very important art work in industrial fields has been considered to content that the copyright protection is urgently needed. This paper presents a watermarking scheme based on k-means++ for CAD design drawing. One CAD design drawing consists of several layers and each layer consists of various geometric objects such as LINE, POLYLINE, CIRCLE, ARC, 3DFACE and POLYGON. POLYLINE with LINE, 3DFACE and ARC that are fundamental objects make up the majority in CAD design drawing. Therefore, the proposed scheme selects the target object with high distribution among POLYLINE, 3DFACE and ARC objects in CAD design drawing and then selects layers that include the most target object. Then we cluster the target objects in the selected layers by using k-means++ and embed the watermark into the geometric distribution of each group. The geometric distribution is the normalized length distribution in POLYLINE object, the normalized area distribution in 3DFACE object and the angle distribution in ARC object. Experimental results verified that the proposed scheme has the robustness against file format converting, layer attack as well as various geometric editing provided in CAD editing tools.

• The Journal of Advanced Prosthodontics
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• v.9 no.6
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• pp.439-446
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• 2017

PURPOSE. To evaluate the effects of different surface treatments on the bond strength of novel CAD/CAM restorative materials to resin cement by four point bending test. MATERIALS AND METHODS. The CAD/CAM materials under investigation were e.max CAD, Mark II, Lava Ultimate, and Enamic. A total of 400 bar specimens ($4{\times}1.2{\times}12mm$) (n=10) milled from the CAD/CAM blocks underwent various pretreatments (no pretreatment (C), hydrofluoric acid (A), hydrofluoric acid + universal adhesive (Scotchbond) (AS), sandblasting (Sb), and sandblasting + universal adhesive (SbS)). The bars were luted end-to-end on the prepared surfaces with a dual curing adhesive resin cement (Variolink N, Ivoclar Vivadent) on the custom-made stainless steel mold. Ten test specimens for each treatment and material combination were performed with four point bending test method. Data were analyzed using ANOVA and Tukey's test. RESULTS. The surface treatment and type of CAD/CAM restorative material showed a significant effect on the four point bending strength (FPBS) (P<.001). For LDC, AS surface treatment showed the highest FPBS results ($100.31{\pm}10.7MPa$) and the lowest values were obtained in RNC ($23.63{\pm}9.0MPa$) for control group. SEM analyses showed that the surface topography of CAD/CAM restorative materials was modified after treatments. CONCLUSION. The surface treatment of sandblasting or HF acid etching in combination with a universal adhesive containing MDP can be suggested for the adhesive cementation of the novel CAD/CAM restorative materials.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.663-664
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• 2009

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.4
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• pp.375-384
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• 2005

Three dimensional urban models are being increasingly applied for various purposes such as city planning, telecommunication cell planning, traffic analysis, environmental monitoring and disaster management. In recent years, technologies from CAD and GIS are being merged to find optimal solutions in three dimensional modeling of urban buildings. These solutions include modeling of the interior building space as well as its exterior shape visualization. Research and development effort in this area has been performed by scientists and engineers from Computer Graphics, CAD and GIS. Computer Graphics and CAD focussed on precise and efficient visualization, where as GIS emphasized on topology and spatial analysis. Complementary research effort is required for an effective model to serve both visualization and spatial analysis purposes. This study presents an efficient way of using the CAD plans included in the building register documents to reconstruct the internal space of buildings. Topological information was built in the geospatial database and merged with the geometric information of CAD plans. as well as other attributal data from the building register. The GIS network modeling method introduced in this study is expected to enable an effective 3 dimensional spatial analysis of building interior which is developing with increasing complexity and size.

• Journal of Korean society of Dental Hygiene
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• v.16 no.5
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• pp.695-700
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• 2016

Objectives: The purpose of the study was to investigate the effect of CAD/CAM ceramic thickness on shade. Methods: 24 disk-shaped ceramic specimens (E.Max CAD & Empress CAD, $12mm{\times}12mm$) were prepared and divided into 4 groups (n=6). Ceramic specimens in 2 thicknesses (0.8 mm, 1.0 mm) were made low translucency(LT) shade A2. All specimens were measured as L*, a*, b* using spectrophotometer. The color differences(${\Delta}E$ values) between the specimen and a control target block ($12{\times}12{\times}1.2mm$) were calculated. Two-way ANOVA performed between 2 groups(material and thickness). Results: As the thickness increased, the $L^*$ (for all groups) and $b^*$ value (for all groups) increased and the $a^*$ value(for LR group) decreased. The mean color differences caused by thickness was acceptible (${\Delta}E$ > 2) for group LD1. But the mean color differences by thickness were not selected (${\Delta}E$ < 2) for group LD2, LR1, LR2. Conclusions: The different thickness can influence the final color of CAD/CAM ceramic.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.4
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• pp.98-108
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• 1998

Hull design data is currently prepared by a 2D CAD system and re-input to 3D CAD systems specialized for detail design or to a structural analysis system. In this paper, sharing design data among different CAD systems has been studied. Based on STEP methodology, a neutral model is generated from 2D AutoCAD drawings. To handle a geometric data of this model, the non-manifold model of ACIS is used because it can support various CAD data representation such as 2D graphic entities, 3D wireframe, 3D surface model, and solid B-Rep/CSG model. It is observed that a mon-manifold model can easily be transformed to a 3-D wireframe model for the hull detail design system AutoDef or a FE model for the structural analysis system Nastran.

• International Journal of CAD/CAM
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• v.5 no.1
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• pp.39-47
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• 2005

Different CAx systems are being utilized throughout the product lifecycle due to the practical reasons in the supply chain and design processes. One of the major problems facing enterprises of today is how to share and exchange data among heterogeneous applications. Since different software applications use different terminologies, it is difficult to share and exchange the product data with internal and external partners. This paper presents a method to enhance the CAD model interoperability based on feature ontology. The feature ontology has been constructed based on the feature definition of modeling commands of CAD systems. A method for integration of semantic data has been proposed, implemented, and tested with two commercial CAD systems.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.2
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• pp.68-74
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• 1998

In this work, we have been concerned with developing an intelligent mold design system for plastic injection molding on the AutoCAD. We have concentrated on building a viable environment, including a mold parts database and a menu-driven user interface. This provides a more interactive and interface for selection of optimal mold-base and mold parts in mold design system. This work presents a method which allows the designer to select the mold parts and mold-base directly within an AutoCAD environment. It can also automatically generate detailed 3D drawings of the mold parts and mold-base. The system shows its potential capability for future enhancement. Since the system is independent of the data, it could easily be extended to other mold-bases and mold parts. In addition, it can be linked to the molding analysis system by creating subtracted 3-D models.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.3
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• pp.1-8
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• 2002

This study is continuous with the study I (A Study on the Modeling) and the sample impeller of this study is defined by the modeling process of the exclusive CAD/CAM system developed in the study Ⅰ. And, this study describes a method for the 5-axis machining of impeller blades formed by ruled surface. Therefore, the exclusive CAD/CAM system is the software for modeling md machining of impeller blades. By using the machining method suggested in this study, we could manufacture impeller blades on 5-axis CNC machining center and the machined impeller was very agreeable to the designed impeller. Thus, theories proposed in this study can be very useful for the 5-axis machining of impeller blades.