• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.5 no.4
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• pp.18-25
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• 1996

In this study, we have developed the stereolithography system that supports the development of a products. This paper presents the development of the stereolithography system. The system is composed of hardware, software and control part. The software converts a STL file to NC data and displays the monitoring figure in control part. The hardware part deals with structure of machine. The most important theme in this paper is LG-SLCAM software. This software can generate NC data and scanning condition data from a STL file semiautimatically. On the basis of three diensional shapes, it makes data for support structure from STL file. The effectiveness of using out stereolithography system is confirmed by processes of good development.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1995.10a
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• pp.31-31
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• 1995

TIN은 Triangulated Irregular Network의 약자로 불규칙한 대소삼각형의 집합으로 삼각망을 구성, 지표면을 Digital Terrain Model로 만드는 기법이다. 지표면(해저지형포함)은 수치화된 등고선의 벡터 데이터와 점의 표고데이터 또는 표고 평행배열의 Raster데이터로부터 모형화되며 또는 제 3의 방법인 TIN에 의해 모형화된다. 이 TIN에 의한 도형은 컴퓨터가 위성측량, 항공측량, 광파측량 또는 음차수심측량등 측량결과를 받아 어떤 특정 프로그램을 구동 삼각형의 정점에 해당하는 점의 X, Y, Z의 좌표로부터 닫한 삼각형을 작성한다. (중략)

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.1
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• pp.20-31
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• 2024

This study was conducted to investigate the changes in the structure of benthic communities resulting from aquaculture activities and to assess the benthic health status of surface sediment in Gangjin Bay, a region known for concentrated shellfish aquaculture on the southern coast of Korea. Survey stations were divided into longline culture, bottom culture, and non-cultivation areas. The spatiotemporal distribution of physiochemical factors such as the grain size, water temperature, salinity, and total organic carbon in Gangjin Bay showed no significant differences between sampling stations. However, the species number, density, and diversity were relatively lower at the sampling stations in the bottom culture areas than at the other stations throughout the entire survey period. Cluster analysis and principal coordinates analysis also clearly distinguished the benthic communities in the bottom culture areas from those in the other sampling areas. At the sampling stations in the longline culture and non-cultivation areas, Scolectoma longifolia and Sigambra tentaculata, which are indicator species of organically enriched areas, appeared as dominant species. However, excluding some stations influenced by physical factors such as the water depth and current speed, the occupancy rate was not high. The health assessment results, conducted using the fisheries environment assessment method, revealed good conditions with Grades 1 and 2 across the entire area. However, an examination of the spatiotemporal changes in benthic communities and the benthic health index indicated that the benthic environment in the bottom culture areas was affected by physical disturbances.

• Journal of the Korea Computer Graphics Society
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• v.18 no.4
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• pp.1-8
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• 2012

We present improved deformation energy to enhance the visual quality of a shape deformation technique, where we preserve the local structure of an input planar shape. The deformation energy, in general, consists of several constraints such as Laplacian coordinate constraint to preserve the quality of deformed silhouette edges, mean value coordinates and edge length constraints to preserve the quality of deformed internal shape, and user-specified position constraints to control the shape deformation. When the positions of user-specified vertices change, shape deformation techniques compute the positions of the other vertices by means of nonlinear least squares optimization to minimize the deformation energy. When a user-specified vertex changes its position rapidly, it is frequently observed that the visual quality of the deformed shape decrease rapidly, which is mainly caused by unnecessary enlargement of the Laplacian vectors and unnecessary change of the edge directions along the boundary of the shape. In this paper, we propose improved deformation energy by prohibiting the Laplacian and edge length constraints from changing unnecessarily. The proposed deformation energy incorporated with well-known optimization technique can enhance the visual quality of shape deformation along the silhouette and within the interior of the planar shape while sacrificing only a little execution time.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.10
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• pp.49-54
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• 2007

As digital contents based on 3D graphics are increased, the requirement for low power 3D graphic hardware for mobile devices is increased. We design a transformation engine for mobile 3D graphic processor. We propose a simplified transformation engine for mobile 3D graphic processor. The area of the transformation engine is reduced by merging a mapping transformation unit into a projective transformation unit and by replacing a clipping unit with a selection unit. It consists of a viewing transformation unit a projective transformation unit a divide by w nit, and a selection unit. It can process 32 bit floating point format of the IEEE-754 standard or a reduced 24 bit floating point format. It has a pipelined architecture so that a vertex is processed every 4 cycles except for the initial latency. The RTL code is verified using an FPGA.

• Journal of IKEEE
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• v.19 no.4
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• pp.590-595
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• 2015

This paper proposes a design of efficient hierarchy structure in the tile based rasterizer. The proposed hierarchy structure avoids unnecessary calls of low level tile at which a calculation is not required. A low level tile is classified into three categories based on its maximum, minimum position, and inside outside test. The necessity of calculations on the corresponding low level tile can be determined by its classification. The overall amount of computations for graphic processing can be reduced by not calling for the low level tile with no calculation. The proposed hierarchy structure can reduce an execution time of graphic processing. It shows higher efficiency with the more vertex density of formulating 3D model.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.11
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• pp.2107-2115
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• 2007

In this paper, the scan conversion processor which converts the triangle represented by three vertices into pixel-level screen coordinates, depth coordinate, and color data is designed. The processor adopts scan-line algorithm which decomposes triangle into horizontal spans and then transforms the span into pixel data. By supporting top-left filling convention, it ensures that triangles that share an edge do not produce any dropouts or overlaps between adjacent polygons. It consists of about 21,400 gates and its maximum operating frequency is about 80 Mhz under 0.35um CMOS technology. Because its maximum pixel rate is about 80 Mpixels/sec, it can be applicable to mobile graphics application.

• Electronics and Telecommunications Trends
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• v.21 no.4 s.100
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• pp.12-21
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• 2006

3차원 메시 모델은 컴퓨터 그래픽스, 애니메이션, 3D 모델링, CAD, 3D 게임 등의 다양한 응용 분야에서 광범위하게 사용되고 있다. 그러나, 현실감을 줄 수 있는 고해상도의3차원 모델은 그 정보량의 방대함으로 인해 처리, 저장, 전송 등에 있어 여러 가지 어려움이 따른다. 따라서, 이를 효율적으로 압축하여 저장 및 전송하기 위한 3차원 메시 모델 부호화 기술이 연구되어 왔다. 본 고에서는 3차원 메시 부호화 기술에 대한 연구 개발 동향과 이에 대한 표준화 동향을 소개한다. 또한, 3차원 메시 부호화 기술과 관련하여 ETRI에서 연구중인 정점 및 면 순서 정보 부호화 기술과 텍스처 좌표 부호화 기술의 내용과 이에 대한 연구 활동 현황을 요약하고, 주요 이슈 논의 및 향후 전망에 대해 간략히 살펴보고자 한다.

• Journal of Environmental Science International
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• v.6 no.5
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• pp.541-550
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• 1997

A least-square regression analysis is applied for the estimation of velocity streamfunction field based on discretely sampled current meter data. The coefficients of a streamfuunction that is expanded in terms of trigonometric basis function are obtained by enforcing the horizontal non-divergence of two-dimensional flow field. This method avoids Interpolation and gives a root-mean-square (rms) residual of fit which Includes the divergent part and noisiness of oceanic data. The Implementation of the method Is done by employing a boundary-fitted, curvilinear orthogonal coordinate which facilitates the specification of boundary conditions. An application is successfully made to the Texas-Louisiana shelf using the 32 months current meter data (31 moorings) observed as a part of the Texas-Louisiana Shelf and Transport Processes Study (LATEX). The rms residual of the fitting is relatively small for the shelf, which indicates the field Is Ivell represented by the streamnfunction.

• Journal of the Korea Computer Graphics Society
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• v.27 no.1
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• pp.1-8
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• 2021

This paper proposes a simple deformation method for editing the trajectory of a walking motion with preserving its style. To this end, our method analyzes the trajectory of the root joint into the graph and deforms it by applying the graph Laplace operator. The trajectory of the root joint is presented as a graph with a vertex defined the position and direction at each time frame on the motion dataThe graph transforms the trajectory into the differential coordinate, and if the constraints are set on the trajectory vertex, the solver iterative approaches to the solution. By modifying the root trajectory, we can continuously vary the walking motion, which reduces the cost of capturing a whole motion that is required. After computes the root trajectory, other joints are copied on the root and post-processed as a final motion. At the end of our paper, we show the application that the character continuously walks in a complex environment while satisfying user constraints.