• 한국CDE학회논문집
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• 제19권3호
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• pp.294-304
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• 2014

This paper presents a real-time rendering algorithm of large-scale geometric data using GLSL (OpenGL shading language). It details the VAO (vertex array object) and VBO(vertex buffer object) to be used for up-loading the large-scale point clouds and polygon meshes to a graphic video memory, and describes the shader program composed by a vertex shader and a fragment shader, which manipulates those large-scale data to be rendered by GPU. In addition, we explain the global rendering procedure that creates and runs the shader program with the VAO and VBO. Finally, a rendering performance will be measured with application examples, from which it will be demonstrated that the proposed algorithm enables a real-time rendering of large amount of geometric data, almost impossible to carry out by previous techniques.

• 전기의세계
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• 제30권5호
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• pp.297-305
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• 1981

The problem of finding shortest paths between every pair of points in a network is solved employing and optimal network decomposition in which the network is decomposed into a number of subnetworks minimizing the number of cut-set between them while each subnetwork is constrained by a size limit. Shortest path computations are performed on individual subnetworks, and the solutions are recomposed to obtain the solution of the original network. The method when applied to large scale networks significantly reduces core requirement and computation time. This is demonstrated by developing a computer program based on the method and applying it to 30-vertex, 160-vertex, and 273-vertex networks.

• 한국수학교육학회지시리즈A:수학교육
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• 제53권4호
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• pp.493-507
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• 2014

The purpose of this study is to analyze how high school students form and interpret the mental image in the process of solving regular polyhedron problems. For this purpose, a set of problems about the regular polyhedron's vertex is developed on the base of the regular polyhedron's duality and circulation. and applied to 2 students of the 12th graders in D high school. After 2 hours of teaching and learning and another 2 hours of mental image-analysis process, the following research findings are obtained. Fisrt, a student who recorded medium high-level grade in the national scholastic test can build the dynamic image or the patten image in the process of solving regular polyhedron's vertex problems by utilizing the 3D geometry program. However, the other student who recorded low-level grade can build the concrete-pictorial image. Second, pattern image or dynamic image can help students solve the regular polyhedron's vertex problems by proper transformation of informations and the mental images while the concrete-pictorial image does not help. Hence, it is recommended that the mathematics teachers should develop teaching and learning materials about the regular polyhedron's duality and circulation and also give students suitable questions to build the various mental images.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.1003-1006
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• 2005

Vertex shader of GPU in personal computer is advanced in functions as to be half of traditional fixed T&L functions. And, capacity of memory for saving resources to process instructions is unlimited. GPU that can be programmed by programmer is needed for mobile system as well as personal computer. In this paper, we implement software virtual machine for vertex shader using C++ Language. Our goal is designing hardware GPU that can apply to mobile system. The virtual machine consists of nVidia GPU instructions. Input Data to virtual machine is generated by Microsoft fxc compiler. That is to say, Input Data is compiled shader program written in HLSL, Cg, or ASM. The virtual machine will be a reference model for designing hardware GPU and can be used for Testbed to test added or modified instruction.

• 문화기술의 융합
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• 제9권3호
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• pp.81-94
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• 2023

본 연구는 2022년 Skytrax가 실시한 항공사 평가 중 최상위 등급에 해당하는 카타르 항공, 싱가포르 항공, 에미레이트 항공, ANA 항공과 9위인 대한항공을 대상으로 Twitter 상의 소셜 네트워크 구조를 비교 분석하여 그 차이점을 규명하는 데 목적이 있다. 이를 위해 본 연구는 소셜 네트워크 분석 프로그램인 NodeXL를 활용하였다. 항공사별 소셜 네트워크의 차이를 비교하기 위한 지표로 Vertex, Unique Edges, Single-Vertex Connected Components, Maximum Geodesic Distance, Average Geodesic Distance, Average Degree Centrality, Average Closeness Centrality, 그리고 Average Betweenness Centrality를 활용한 결과, 종합적으로 싱가포르 항공의 소셜 네트워크가 다른 항공사의 것이 비해 강한 연결망을 형성하고 있는 것으로 나타났다. 또한, 항공사별 소셜 네트워크내에서 정보 및 자원의 흐름뿐만 아니라 상호작용에 큰 영향을 미치는 유력자(Influencer)가 누구이며, 어떤 역할을 하는지를 확인 결과에서도 카타르 항공과 싱가포르 항공이 다른 항공사에 비해 우수한 것으로 평가되었다. 본 연구는 이런 분석 결과를 토대로, 항공사의 소셜 네트워크 활용 필요성과 유용성 제고 차원에서 시사점을 제시하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제35권2호
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• pp.278-287
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• 2011

본 논문은 IMO에서 선박정보 통합 및 안전 운항을 목적으로 채택한 SOLAS(Safety of Life at Sea) 선박의 표준 프로토콜인 NMEA 2000을 기반으로 한 게이트웨이를 구현하였다. 이를 위해 CAN, RS232, USB, Ethernet을 Xilinx에서 제공되는 MicroBlaze와 FPGA를 이용해 Vertex4기 반 ML401 보드에 포팅하고 NMEA 2000 스택을 탑재하였다. 다양한 프로토콜을 수신하여 변환할 수 있도록 요구되는 통신 속도를 준수하여 설정하였다. 게이트웨이에서 변환된 데이터의 검증을 위해 PC 기 반의 모니터링 프로그램을 제작하고 NMEA 2000 네트워크의 데이터를 PC에서 수신할 수 있도록 네트 워크를 구성하였다. PC에서 수신된 데이터를 모니터링 프로그램을 통해 분석하고 게이트웨이의 성능을 검증하였다.

• ETRI Journal
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• 제33권1호
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• pp.89-99
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• 2011

We construct surfaces with darts, creases, and corners by blending different types of local geometries. We also render these surfaces efficiently using programmable graphics hardware. Points on the blending surface are evaluated using simplified computation which can easily be performed on a graphics processing unit. Results show an eighteen-fold to twenty-fold increase in rendering speed over a CPU version. We also demonstrate how these surfaces can be trimmed using textures.

• 한국안전학회지
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• 제35권3호
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• pp.105-115
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• 2020

This study compares the difference of fit factors (FF) and visual acuity according to masks and eyeglasses preferences for 54 participants. We the precautions and behaviors of discomfort when wearing masks of eyewear wearers. Contact lens discomfort and priority action of complaints was investigated Glasses fitting factors is Optical Center Height(OH), Vertex Distance(VD) and Pantoscopic Angle(PA). We measured those factors and expressed by the ratio of standard point and change point. Quantitative fit factor was measured by Portacount Pro+ 8038. Also, we selected to 6 exercises among 8 exercises OSHA QNFT (Quantitative Fit testing) protocol to measure the fit factors. The pass/ fail criterion of FF was set at 100. Visual acuity(VA) test chart is developed by Chunsuk Han was used, Descriptive statistics was performed. Descriptive statistics(SAS ver 9.2), it is used geometric means, Wilcoxon analysis(P=0.05) When wearing the mask preferentially, fit factor(FF) was high according to the step of glasses fitting parameter. on the other hand, when the glasses first choice, the visual acuity(VA) was high. there was no significant difference. In the case of fit factor (FF), mask first choice/ glasses first choice is OH (p=0.671/ p=0.332), VD (p=0.602/ p=0.571) and PA (p=0.549/ p=0.607). Visual acuity (VA), mask first choice/ glasses first choice is OH (p=0.753/ p=0.386), VD (p=0.815/ p=0.557) and PA (p=0.856/ p=0.562). The workers of workplace and office chose glasses but occupational health workers and students chose mask. In case of discomforts, it was suggested to remove the mask and tolerate discomforts. The main discomforts and usual action of lens were dryness, hyperemia, foreign body sensation, ophthalmodynia, decreased vision and glasses wearing. Therefore, it is necessary to develop a mask wearing method education program considering glasses fitting and develop a hybrid model that minimizes inconvenience when wearing glasses and a mask at the same time.

• 대한토목학회논문집
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• 제30권2D호
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• pp.171-179
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• 2010

본 연구에서는 토목 설계 엔지니어링에서 공사비 산출에 50%이상을 차지하는 토공 공종 분류 및 수량산출을 위한 스케치 도면 요소의 위상 자동 추출 및 토공 형태 패턴 자동인식 모델을 제시하였다. 이를 위해 횡단면도에서 자동으로 폐영역을 인식해 vertex(정점), edge(모서리), face(면)로 위상요소를 추출하고, 각 위상요소간의 관계를 자동 설정할 수 있도록 알고리즘을 연구하였다. 이 위상구조를 이용해 형태 패턴을 수학적으로 정의하고 형태를 자동 인식할 수 있는 모델을 제안하였다. 연구 결과로 기존 토공엔진에서 처리하기 어려웠던 토공 형태도 토공 형태 패턴 모델을 확장함으로써 쉽게 처리할 수 있었으며, 횡단면도에서 수량을 산출할 수 있는 일반적인 형태 패턴 인식 모형을 얻을 수 있었다. 개발된 모형을 이용한다면, 토목에서 다양한 분야의 토공 분류 및 수량 산출 업무를 자동화해 비용을 줄이고 수량 산출의 정확도는 높일 수 있다고 판단된다.

• KIEAE Journal
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• 제16권1호
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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.