• 디자인학연구
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• 제13권
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• pp.83-91
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• 1996

본 연구는 제품디자인 개발과정에서 많이 활용되고 있는 워크스테이션(workstation)의 하나인 알라아스(Alias)를 활용하여 정확한 3차원 모델 링 데이터를 구축하는 과정을 비디오 개발 과정을 통해 제시하였다. 먼저 알리아스(Alias) 모델 링의 기본이 되는 NURBS 곡선의 특징과 표면 생성 방법을 파악하였다. 기본적인 표면을 생성한 후 사실적인 이미지 표현을 위해 적용하게 되는 질감표현(texture), 조명(lighting), 렌더링(rendering) 방법을 파악하였다. 제품 디자인의 모델 링에 필요한 이러한 요소들을 비디오 디자인 개발 과정을 통해 종합적인 활용방향을 제시하였다.

• Nuclear Engineering and Technology
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• 제3권3호
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• pp.121-128
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• 1971

중성자속의 각분포를 unified modal-nodal 방법으로 전개하였다. 몇몇 표준 nodal 해석법이나 modal 해석법은 이 방법의 특수한 경우임을 밝혔다. 중성자의 발생과 산란이 등방성인 경우에 단일에너지 수송방정식을 modal-nodal moment 형으로 도출하여 고유치를 구하였다. 중성자가 생성되지 않는 매질 내에서의 역확산거리를 근사적으로 계산한 결과 표준방법으로 한 것보다 더 정화하였다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.399-402
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• 2003

This paper deals with the making avatar like a caricature from human face image which is made by web camera. Generally, the Image made by web camera is not low quality but also, there are always various lights and backgrounds. So, It is impossible to recognize a human face's contour by some methods which only find some feature points of a image. Therefore, In this paper, we propose a new method for overcoming defeat of that methods. First, we got the area of human face roughly by color information. And then, we could find the exact human face's contour by using B-spline Snake.

• Journal of Information Technology Applications and Management
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• 제10권3호
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• pp.45-54
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• 2003

Security system with web camera remarkably has been developed at an Internet era. Using transmitted images from remote camera, the system can recognize current situation and take a proper action through web. Existing motion detection methods use simply difference image, background image techniques or block matching algorithm which establish initial block by set search area and find similar block. But these methods are difficult to detect exact motion because of useless noise. In this paper, the proposed method is updating changed background image as much as $N{\times}M$pixel mask as time goes on after get a difference between imput image and first background image. And checking image pixel can efficiently detect motion by computing fixed distance pixel instead of operate all pixel.

• 한국공작기계학회논문집
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• 제16권3호
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• pp.81-87
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• 2007

It is important to investigate the relationship between weld process parameters and weld bead geometry for adaptive arc robot welding. However, it is difficult to predict an exact back-bead owing to gap in process of butt welding. In this paper, the quantitative prediction system to specify the relationship external weld conditions and weld bead geometry was developed to get suitable back-bead in butt welding which is widely applied on industrial field. Multiple regression analysis and artificial neural network were used as the research methods. And, the results of two prediction methods were compared and analyzed.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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• pp.283-286
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• 2001

Based on a fuzzy system representation of gray scale images, we derive an edge detection algorithm whose convolution kernel is different from the known kernels such as those of Roberts', Prewitt's or Sobel's gradient. Our fuzzy system representation is an exact representation of the bicubic spline function which represents the gray scale image approximately. Hence the fuzzy system is a continuous function and it provides a natural way to define the gradient and the Laplacian operator. We show that the gradient at grid points can be evaluated by taking the convolution of the image with a 3 3 kernel. We also show that our gradient coupled with the approximate value of the continuous function generates an edge detection method which creates edge images clearer than those by other methods. A few examples of applying our methods are included.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.769-772
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• 1995

Most turbo machines, which operate at high speeds, such as gas turbines, jet engines, pumps, and compressors are prone to perrturbing vibrations. The best vibration control method for rotors is to eliminate destabilizing factors. Careful balancing application of "more stable" oil-lubricated bearing, such as tilting pad bearings or use of anti-swirl devices in seals, are examplse of passive vibration control methods. the use of magnetic bearing is an active control method. An obvious advantage of active control is that it provides damping (or modifies system stiffness or other parameters) only when there is a need for that, i.e., in emergency states, while not affecting the rotor normal operational conditions. Moreover, active control methods provide exact position control through on-line control. In this study, a magnetic actuator, digital contrliier using DSP, and bipolar operational power supply/amplifiers were developed to show the effectiveness of reducing robot vibration. Also the curve fitting procedure to obtain the transfer function of frequency dependent component was developed. Results presented in this dissertation will provide a well-defined technical parameters in designing magnetic damper system.er system.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제8권2호
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• pp.23-38
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• 2004

We consider finite element methods applied to a class of quasi parabolic integro-differential equations in $R^d$. Global strong superconvergence, which only requires that partitions are quasi-uniform, is investigated for the error between the approximate solution and the Sobolev-Volterra projection of the exact solution. Two order superconvergence results are demonstrated in $W^{1,p}(\Omega)\;and\;L_p(\Omega)$, for $2\;{\leq}p\;<\;{\infty}$.

• Smart Structures and Systems
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• 제13권1호
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• pp.111-135
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• 2014

Based on the Reissner mixed variational theorem (RMVT), finite rectangular layer methods (FRLMs) are developed for the three-dimensional (3D) linear buckling analysis of simply-supported, fiber-reinforced composite material (FRCM) and functionally graded material (FGM) sandwich plates subjected to bi-axial compressive loads. In this work, the material properties of the FGM layers are assumed to obey the power-law distributions of the volume fractions of the constituents through the thickness, and the plate is divided into a number of finite rectangular layers, in which the trigonometric functions and Lagrange polynomials are used to interpolate the in- and out-of-plane variations of the field variables of each individual layer, respectively, and an h-refinement process is adopted to yield the convergent solutions. The accuracy and convergence of the RMVT-based FRLMs with various orders used for expansions of each field variables through the thickness are assessed by comparing their solutions with the exact 3D and accurate two-dimensional ones available in the literature.

• 영어어문교육
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• 제4호
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• pp.117-130
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• 1998

It is simply not true that anyone who can speak English can teach it. Language teaching is both a science and an art; its methods are based on a theoretical foundation and implemented by techniques. However, at a time like the present, when the scientific justification for our methods seems to be uncertain, we should concern ourselves less with theory and more with developing techniques that work with our students. The success of language teaching must be evaluated by the effectiveness of the techniques used. The purpose of the present study is to suggest some useful techniques that the teacher can utilize in teaching English as a foreign language in the elementary school. The techniques suggested are based on the investigation of the characteristics peculiar to children. The investigation takes into account cognitive, affective, and linguistic factors affecting specific techniques. The goal of language teaching is communication and all techniques should move toward this end. The resourceful teacher will provide techniques which exact more and more from the students and less and less from the teacher.