• 한국전기전자재료학회논문지
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• 제14권1호
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• pp.26-33
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• 2001

The proposed system was composed of pre-processor which was executing binary/high-pass filtering and post-processor which ranged from statistic data to prediction. In post-processor work, step one was filter process of image, step two was image recognition, and step three was destruction degree/time prediction. After these processing, we could predict image of the last destruction timestamp. This research was produced variation value according to growth of tree pattern. This result showed improved correction, when this research was applied image Processing. Pre-processing step of original image had good result binary work after high pas- filter execution. In the case of using partial discharge of the image, our research could predict the last destruction timestamp. By means of experimental data, this prediction system was acquired $\pm$3.2% error range.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.319-322
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• 2001

The proposed system was composed of pre-processor which was executing binary/high-pass filtering and post-processor which ranged from statistic data to prediction. In post-processor work, step one was filter process of image, step two was image recognition, and step three was destruction degree/time prediction. After these processing, we could predict image of the last destruction timestamp. This research was produced variation value according to growth of tree pattern. This result showed improved correction, when this research was applied image Processing. Pre-processing step of original image had good result binary work after high pass- filter execution. In the case of using partial discharge of the image, our research could predict the last destruction timestamp. By means of experimental data, this Prediction system was acquired ${\pm}$3.2% error range.

• 한국산학기술학회논문지
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• 제16권10호
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• pp.6673-6678
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• 2015

최근 빈번히 건설되고 있는 비정형 건축물들은, 개별부재의 수직/수평적 연결방식 에서 벗어나, 외관 및 내부 구성요소들의 단면이 자유롭게 변화되는 곡선의 형태를 띠고 있다. 이러한 구조물의 안정성 평가를 위해서 고전적 방식의 유한요소 해석기법이 적용된 상용프로그램이 사용되고 있으나, 과도한 절점분할 방식 또는 유한요소망(Finite Element Mesh)의 도입으로 인하여 해석시간이 길어지고 사용성 및 해석 정밀도가 낮은 문제점을 안고 있다. 따라서 본 연구에서는, 전술된 문제점을 개선하기 위하여, 임의의 곡률을 가진 단위 부재 및 단위요소에 대한 수학적 해석모형을 활용하여 비정형구조물에 대한 구조안정성 평가를 효과적으로 수행할 수 있는 전후처리 모듈을 개발하였다. 본 연구에서 개발된 전후처리 모듈은 곡선형 부재의 곡률을 NURBS 제어점을 이용하여 제어할 수 있도록 개발되었으며, 그로 인해 상용프로그램보다 빠른 형상 모델링이 가능하였다. 또한, 자유로운 형상에 대한 시각적 확인이 가능하여 비정형 건축물의 형상과 거동양상의 현실적인 묘사가 가능하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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• pp.270-274
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• 1996

Until recently pre & post-processing of finite element model has been heavily relied on expensive graphic peripheral devices. But today, with the aid of inexpensive microcomputers, very effective pre & postprocessor graphics has been developed. In this study, Pre & Post processor(MASSPRE, MASSPOST) of prediction analysis of thermal stress in mass concrete structure is developed. The developed pre & post processors are raise to the efficiency in making input data for the main program and analysis of the results produced by the main program. This MASSPOST presents a stress contour graph, volume slice, time-temperature history graph, time-stress history graph, etc.

• 전산구조공학
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• 제22권5호
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• pp.44-51
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• 2009

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2410-2413
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• 2005

Finite element method (FEM) has been widely used as a useful numerical method that can analyze complex engineering problems in electro-magnetics, mechanics, and others. CEMTool, which is similar to MATLAB, is a command style design and analyzing package for scientific and technological algorithm and a matrix based computation language. In this paper, we present new 3D FEM package in CEMTool environment. In contrast to the existing CEMTool 2D FEM package and MATLAB PDE (Partial Differential Equation) Toolbox, our proposed 3D FEM package can deal with complex 3D models, not a cross-section of 3D models. In the pre-processor of 3D FEM package, a new 3D mesh generating algorithm can make information on 3D Delaunay tetrahedral mesh elements for analyses of 3D FEM problems. The solver of the 3D FEM package offers three methods for solving the linear algebraic matrix equation, i.e., Gauss-Jordan elimination solver, Band solver, and Skyline solver. The post-processor visualizes the results for 3D FEM problems such as the deformed position and the stress. Consequently, with our new 3D FEM toolbox, we can analyze more diverse engineering problems which the existing CEMTool 2D FEM package or MATLAB PDE Toolbox can not solve.

• 한국주조공학회지
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• 제11권1호
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• pp.54-62
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• 1991

A computer program which consists of pre-processor, main solidification simulator and post-processor has been developed for three dimensional solidification analysis of steel castings. The pre-processor is used for mesh generation in a small personal computing system. The modified finite difference method is adopted for the main solidification simulation algorithm. The post -processor graphically presents the simulation results and shows the formation of shrinkage defects. Several experiments on large steel castings in sand mold were carried out. The temperature variations in casting and mold with time are measured experimentally, and the results are compared with calculation results. Several numerical examples for the prediction of shrinkage cavity in large steel casting of SC42 and SCNCrM2 alloys are compared with experimental results. The effect of sleeve and chills on solidification patterns are also studied. Formation of shrinkage defects for the three cases of experimental castings are relatively well predicted by present model.

• 한국주조공학회지
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• 제13권3호
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• pp.268-275
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• 1993

In gravity die casting, die cooling systems are frequently employed with water cooling to remove the heat of the solidifying metal. Thermal modeling is an important technique in mold design for improving the productivity of the process. Computer simulation system which consists of pre-processor, main solidification simulator and post-processor has been developed for three dimensional solidification analysis of cyclic gravity die casting. The pre-processor is used for mesh generation in a PC system. The modified finite difference method is adopted for the main solidification simulation algorithm during all the casting cycles. The post-processor graphically presents the simulation results. Several experiments in automotive cast piston were carried out. The temperature variations in casting and mold with time are measured experimentally, and the results are compared with calculation results. The effects of cycle number on solidification pattern are also studied. Several experimental results for the prediction of shrinkage defects are compared with calculated results.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1998년도 추계 학술대회논문집
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• pp.29-35
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• 1998

In this paper, the on-going effort and progress for developing an integrated software for automated CFD application is described. As an outcome of the effort devoted so far, a new system, ICFDIT, is developed and introduced in this paper. The new system can be used to solve fluid dynamics problems in a convenient graphical environment, and it includes a pre-processor, a main-processor, and a post-processor. Usage of the system and examples are demonstrated, and some issues for improvement of the system are discussed.

• 한국군사과학기술학회지
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• 제20권4호
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• pp.482-490
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• 2017

The radar signal processing procedure is divided into the pre-processing such as frequency down converting, down sampling, pulse compression, and etc, and the post-processing such as doppler filtering, extracting target information, detecting, tracking, and etc. The former is generally designed using FPGA because the procedure is relatively simple even though there are large amounts of ADC data to organize very quickly. On the other hand, in general, the latter is parallel processed by multiple DSPs because of complexity, flexibility and real-time processing. This paper presents the radar signal processor design using FPGA which includes not only the pre-processing but also the post-processing such as doppler filtering, bore-sight error, NCI(Non-Coherent Integration), CFAR(Constant False Alarm Rate) and etc.