• 대한수학회논문집
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• 제11권2호
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• pp.525-538
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• 1996

In the course of working on the preconditioning of $C^1$-bicubic collocation method, one has to deal with the $C^1$-bicubic splines. In this paper we are concerned with $C^1$-bicubic spline interpolant for a given function. We construct a basis for the space of $C^1$-bicubic splines for a given partition and find the $C^1$-bicubic spline interpolant for a given function defined on a set.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제10권4호
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• pp.255-263
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• 2003

We compare the computing times on the bicubic B-spline dueing to the algorithms.

• 융합신호처리학회논문지
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• 제8권3호
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• pp.163-170
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• 2007

본 논문에서는 bicubic 방법보다 하드웨어 구조는 간단하면서 확대 이미지는 더욱 선명한 polyphase scaler를 제안하였다. 제안된 시스템은 새로운 픽셀을 얻기 위해서 디지털 필터의 group delay를 이용하여 해상도를 확대하는 방식을 사용하였으며 bicubic 방법과 비교하여 더 좋은 성능을 가지면서 하드웨어 구조를 간단히 하여 모바일 기기 등에 쉽게 적용이 가능하도록 설계하였다. 기존 polyhpase 필터는 해상도 확대시 영상을 흐릿하게 하는 blurring 노이즈가 발생하는 문제점을 가지고 있었다. 그래서 입력 신호의 고주파 성분을 증폭시키도록 Polyphase 필터를 boost-up 필터로 수정하여 보다 선명한 결과를 얻을 수 있었다. 본 논문에서 제안하는 polyphase scaler는 Xilinx Virtex2 FPGA를 이용하여 하드웨어 검증을 수행하였다. 제안된 polyphase scaler는 핸드폰 카메라의 디지털 줌으로 사용되어 질 수 있다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.1025-1030
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• 1997

In this study,the procedure of interpolation surface modeling on bicubic spline patch equation and NC machining are presented. The procedure consists of three parts : patch modeling,cutter location data generation,post processing and NC milling machining. For generation of the cutter location data,tangent vectors and units normal vectors on the patch must be calculated. In order to investigate the properties of the interpolation surface created by bicubic spline patch, two kinds of end conditions, clamped end condition and relaxed end condition,were applied in this study. The shape of the patch depends on the magnitide of the tangent vectors and twist vectors at the corners of bicubic surface patch. the patch generated by relaxed end condition more approximated to the surface patch which was given.

• 스마트미디어저널
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• 제9권4호
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• pp.17-25
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• 2020

In the image object classification problem, low-resolution images may have a negative impact on the classification result, especially when the classification method, such as a convolutional neural network (CNN) model, is trained on a high-resolution (HR) image dataset. In this paper, we analyze the behavior of applying a classical super-resolution (SR) method such as bicubic interpolation, and a deep CNN model such as SRCNN to enhance low-resolution (LR) weeds images used for classification. Using an HR dataset, we first train a CNN model for weeds image classification with a default input size of 128 × 128. Then, given an LR weeds image, we rescale to default input size by applying the bicubic interpolation or the SRCNN model. We analyze these two approaches on the Chonnam National University (CNU) weeds dataset and find that SRCNN is suitable for the image size is smaller than 80 × 80, while bicubic interpolation is convenient for a larger image.

• Journal of information and communication convergence engineering
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• 제9권4호
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• pp.420-423
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• 2011

The paper is devoted to problem of spline modeling of multidimensional signals. A new method of nodes location for curves and surfaces computer construction in multidimensional spaces by means of B-splines is presented. The criteria are which links a square-mean error caused by high frequency spline distortions and approximation intervals is determined and necessary theorem is proved. In this method use a theory of entire multidimensional spectra and may be extended for the spaces of three, four and more variables.

• 전자공학회논문지CI
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• 제47권1호
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• pp.152-159
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• 2010

본 논문에서는 기울어진 문자, 다양한 크기, 글씨체, 흐린 문자를 포함한 입력영상의 문자 복원과 인식, 효율적인 도서 검색을 위한 광학문자인식 알고리즘을 제안한다. 본 논문에서 제안한 광학문자 인식알고리즘은 검출부와 인식부로 구성되며, 검출부에서는 복잡한 배경에서 정확한 도서 영역 검출을 위하여 로버츠 에지 연산자와 허도로프 거리 알고리즘을 적용하여 필요한 영역을 검출하였다. 또한 인식부에서는 문자의 크기와 경사도, 부분 손실 등의 영상에 강인성을 갖는 바이큐빅 보간법을 적용하여 데이터 손실 복원과, 반자동 기울기를 갖는 입력 영상의 보정을 하였다. 모의실험 결과 기존 알고리즘 보다 인식률에서는 6%, 검색시간에서는 1.077초 더 우수함을 확인하였다.

• 한국전산유체공학회지
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• 제13권4호
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• pp.13-23
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• 2008

This paper is an extension of previous study[1] on a development of a divergence-free element method using a hermite interpolated stream function. Divergence-free velocity bases defined on rectangles derived herein produce pointwise divergence-free flow fields. Hence the explicit imposition of continuity constraint is not necessary and the Galerkin finite element formulation for velocities does not involve the pressure. The divergence-free element of the previous study employed hermite (serendipity) cubic for interpolation of stream function, and it has been noted a possible discontinuity in variables along element interfaces. This deficiency can be removed by use of a hermite bicubic interpolated stream function, which requires four degrees-of-freedom at each element corners. Those degrees-of-freedom are the unknown variable, its x- and y-derivatives and its cross derivative. Detailed derivations are presented for both solenoidal and irrotational basis functions from the hermite bicubic interpolated stream function. Numerical tests are performed on the lid-driven cavity flow, and results are compared with those from hermite serendipity cubics and a stabilized finite element method by Illinca et al[2].

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 학술대회
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• pp.33-41
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• 2008

This paper is an extension of previous study[9] on a development of a divergence-free element method using a hermite interpolated stream function. Divergence-free velocity bases defined on rectangles derived herein produce pointwise divergence-free flow fields. Hence the explicit imposition of continuity constraint is not necessary and the Galerkin finite element formulation for velocities does not involve the pressure. The divergence-free element of the previous study employed hermite serendipity cubic for interpolation of stream function, and it has been noted a possible discontinuity in variables along element interfaces. This deficiency can be removed by use of a hermite bicubic interpolated stream function, which requires at each element corners four degrees-of-freedom such as the unknown variable, its x- and y-derivatives and its cross derivative. Detailed derivations are presented for both solenoidal and irrotational bases from the hermite bicubic interpolated stream function. Numerical tests are performed on the lid-driven cavity flow, and results are compared with those from hermite serendipity cubics and a stabilized finite element method by Illinca et al[7].

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년 추계학술대회논문집
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• pp.33-41
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• 2008

This paper is an extension of previous study[9] on a development of a divergence-free element method using a hermite interpolated stream function. Divergence-free velocity bases defined on rectangles derived herein produce pointwise divergence-free flow fields. Hence the explicit imposition of continuity constraint is not necessary and the Galerkin finite element formulation for velocities does not involve the pressure. The divergence-free element of the previous study employed hermite serendipity cubic for interpolation of stream function, and it has been noted a possible discontinuity in variables along element interfaces. This deficiency can be removed by use of a hermite bicubic interpolated stream function, which requires at each element corners four degrees-of-freedom such as the unknown variable, its x- and y-derivatives and its cross derivative. Detailed derivations are presented for both solenoidal and irrotational bases from the hermite bicubic interpolated stream function. Numerical tests are performed on the lid-driven cavity flow, and results are compared with those from hermite serendipity cubics and a stabilized finite element method by Illinca et al[7].