• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.321-322
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• 2020

본 논문에서는 대한민국에서 드론을 포함한 UAV를 합법적으로 비행할 수 있도록 관련 구역 정보를 제공하는 서비스를 구현한다. Mapbox API를 이용하여 3D지도를 설정하고 드론 관련 구역 정보를 레이어화 한다. 레이어는 GL JS를 이용하여 인터페이스를 구성해 지도상에 나타낸다. GL JS로 검색, 네비게이션 기능의 인터페이스를 구성한다. 작성한 결과물을 서버에 업로드하여 서비스를 구현하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.862-865
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• 2011

WebGL is a cross-platform web standard for a low-level 3D graphics API based on OpenGL ES 2.0 and presents 3D graphics in web browsers without installing extra plug-ins. The reason that WebGL is notable is because it is included in the HTML5 standard which is getting the spotlight as a next-generation RIA(Rich Internet Application) platform for variable devices such as PCs, smart phones, table PCs, and smart TVs. In this research, we would like to introduce and develop a behavior engine for easy and rapid authoring of complicated interactions and 3D object's behavior models in WebGL-based contents.

• Journal of Broadcast Engineering
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• v.15 no.4
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• pp.540-546
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• 2010

Since the stereoscopic 3-dimensional (3D) video that provides users with a realistic multimedia service requires twice as much data as 2-dimensional (2D) video, it is difficult to construct the fast system. In this paper, we propose a fast stereoscopic 3D broadcasting system based on the depth information. Before the transmission, we encode the input 2D+depth video using x264, an open source H.264/AVC fast encoder to reduce the size of the data. At the receiver, we decode the transmitted bitstream in real time using a compute unified device architecture (CUDA) video decoder API on NVIDIA graphics processing unit (GPU). Then, we apply a fast view synthesis method that generates the virtual view using GPU. The proposed system can display the output video in both 2DTV and 3DTV. From the experiment, we verified that the proposed system can service the stereoscopic 3D contents in 24 frames per second at most.

• Steel and Composite Structures
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• v.38 no.2
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• pp.151-164
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• 2021

During the pipe forming process, a steel plate undergoes inelastic behavior multiple times under a load condition repeating tension and compression in the circumferential direction. It derives local reduction or increase of yield strength within the thickness of steel pipes by the plastic hardening and Bauschinger effect. In this study, a combined hardening model is proposed to effectively predict variations of yield strength in the circumferential direction of API-X65 and X70 steel pipes with relatively low t/D ratio during the forming process, which is expected to experience accumulated plastic strain of 2~3%, the typical Lüder band range in a low-carbon steel. Cyclic tensile tests of API-X65 and X70 steels were performed, and the parameters of the proposed model for the steels were calibrated using the test results. Bending-flattening tests to simulate repeated tension and compression during pipe forming were followed for API-X65 and X70 steels, and the results were compared with those by the proposed model and Zou et al. (2016), in order to verify the process of material model calibration based on tension-compression cyclic test, and the accuracy of the proposed model. Finally, parametric analysis for the yield strength of the steel plate in the circumferential direction of UOE pipe was conducted to investigate the effects of t/D and expansion ratios after O-forming on the yield strength. The results confirmed that the model by Zou et al. (2016) underestimated the yield strength of steel pipe with relatively low t/D ratio, and the parametric analysis showed that the t/D and expansion ratio have a significant impact on the strength of steel pipe.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.41-45
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• 2005

A new algorithm of the image mapping which is a technique of the elemental image generation is proposed. The proposed method is based on the characteristics of the lens array such as the number, the size and the focal length of the elemental lens. The 3D image generated by 3D graphic API such as OpenGL can be directly adopted without the complex adaptation. Since the image mapping using the proposed method can enhance the speed of the elemental image generation, the computer- generated integral imaging system can be applied to virtual reality system.

• 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.

• Corrosion Science and Technology
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• v.8 no.3
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• pp.119-125
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• 2009

Corrosion assessment has a number of uses but the use considered here is as a precursor to Risk-Based Inspection (RBI) planning. Systematic methods consisting of technical modules of RBI program were used to assess the effect of specific corrosion mechanism on the probability of failure in equipments of petrochemical plants. Especially in part of the damage and corrosion assessment, screening step involved evaluating the combinations of process conditions and construction materials for each equipment item in order to determine which damage mechanisms are potentially active. For general internal corrosion, either API 510 or API 570 was applied as the damage rate in the calculation to determine the remaining life and inspection frequency. In some cases, a measured rate of corrosion may not be available. The technical modules of RBI program employ default values for corrosion, typically derived from published data or from experience with similar processes, for use until inspection results are available. This paper describes the case study of corrosion and damage assessment by using RBI methodology in petrochemical plant. Specifically, this paper reports the methodology and the results of its application to the petrochemical units using the $KGS-RBI^{TM}$ program, developed by the Korea Gas Safety Corporation to suit Korean situation in conformity with API 581 Codes.

• Journal of Cadastre & Land InformatiX
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• v.46 no.2
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• pp.183-196
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• 2016

Ground control points are needed for precision geometric correction of satellite images, and the coordinates of a high-quality ground control point can be obtained from the GPS measurement. However, considering the GPS measurement requires an excessive amount o f t ime a nd e fforts, there is a need for coming up with an alternative solution to replace it. Therefore, we examined the possibility of replacing the existing GPS measurement with coordinates available at online maps to acquire the coordinates of ground control points. To this end, we examined error amounts between the coordinates of ground control points obtained through Daum Map API, and them compared the accuracies between three types of coordinate transformation equations which were used for geometric correction of satellite images. In addition, we used the coordinate transformation equation with the highest accuracy, the coordinates of ground control point obtained through the GPS measurement and those acquired through D aum M ap A PI, and conducted geometric correction on them to compare their accuracy and evaluate their effectiveness. According to the results, the 3rd order polynomial transformation equation showed the highest accuracy among three types of coordinates transformation equations. In the case of using mid-resolution satellite images such as those taken by Landsat-8, it seems that it is possible to use geometrically corrected images that have been obtained after acquiring the coordinates of ground control points through Daum Map API.

• Journal of Digital Convergence
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• v.12 no.6
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• pp.549-557
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• 2014

The learning application of the rotating object utilizing smart devices, it is possible by using the touch functionality and 3D graphics to enhance the realism and operational feeling, and to overcome the limitations of learning content existing. In this study, I designed a "rotation class" based on the learning contents of elementary and middle mathematics education and developed the learning application which driven by smart Android-based device by using Andoroid API class and the OpenGL ES Because this application is driven by the smart devices, learners easily can make the rotated objects and observe them. It can be utilized in various for elementary and middle education.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.558-562
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• 2001

오늘날 월드 와이드 웹(WWW)의 성장과 함께 인터넷 상에서 3차원 세계를 표현해야 할 필요성이 급격히 증가하고 있다. 이러한 요구에 부응하여 VRML97이 개발되었고, 이는 인터넷에서 3차원 그래픽스 데이터의 표준으로 중요한 역할을 해왔다. 그리고 현재 VRML97로 기술된 데이터를 위한 브라우저가 많이 개발되어 왔다. 현재까지는 대부분 OpenGL이나 Direct3D와 같은 API를 주로 사용해왔으나 SUN의 Java3D가 활성화되면서 Java3D 기반의 VRML97 브라우저도 많이 개발되고 있다. 또한 SUN에서는 이미 3D 브라우저를 위한 프로토타입을 개발하여 제공하고 있다. 본 논문에서는 본 연구팀에서 수행하고 있는 서버-클라이언트 모델의 가상현실 시스템의 클라이언트로서의 X3D 브라우저 개발을 위한 기반 연구로서 수행된 Java3D 기반의 VRML97 브라우저의 이벤트 모델에 대하여 기술한다.