• Title/Summary/Keyword: cosine-function

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LOG-SINE AND LOG-COSINE INTEGRALS

  • Choi, Junesang
    • Honam Mathematical Journal
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    • v.35 no.2
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    • pp.137-146
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    • 2013
  • Motivated essentially by their potential for applications in a wide range of mathematical and physical problems, the log-sine and log-cosine integrals have been evaluated, in the existing literature on the subject, in many different ways. The main object of this paper is to present explicit evaluations of some families of log-sine and log-cosine integrals by making use of the familiar Beta function.

A Study On the Design of Cosine, Sine Function Generator for the Display of Graphics (그래픽 디스프레이에 적합한 Cosine, Sine함수 발생기 설계에 관한 연구)

  • Kim, Yong-Sung
    • The Journal of Information Technology
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    • v.8 no.3
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    • pp.1-10
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    • 2005
  • Cosine and Sine function is widely used for the arithmetic, translation, object drawing, Simulation and etc. of Computer Graphics in Natural Science and Engineering. In general, Cordic Algorithm is effective method since it has relatively small size and simple architecture on trigonometric function generation. However profitably it has those merits, the problem of operation speed is occurred. In graphic display system, the operation result of object drawing is quantized and has the condition that is satisfied with rms error less than 1. So in this paper, the proposed generator is composed of partition operation at each ${\pi}/4$ and basic Cosine, Sine function generator in the range of $0{\sim}{\pi}/4$ using the lower order of Tayler's series in an acceptable error range, that enlarge the range of $0{\sim}2{\pi}$ according to a definition of the trigonometric function for the purpose of having a high speed Cosine, Sine function generation. And, division operator using code partition for divisor three is proposed, the proposed function generator has high speed operation, but it has the problems in the other application parts with accurate results, is need to increase the speed of the multiplication.

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FURTHER LOG-SINE AND LOG-COSINE INTEGRALS

  • Choi, Junesang
    • Journal of the Chungcheong Mathematical Society
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    • v.26 no.4
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    • pp.769-780
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    • 2013
  • Motivated essentially by their potential for applications in a wide range of mathematical and physical problems, the log-sine and log-cosine integrals have been evaluated, in the existing literature on the subject, in many different ways. Very recently, Choi [6] presented explicit evaluations of some families of log-sine and log-cosine integrals by making use of the familiar Beta function. In the present sequel to the investigation [6], we evaluate the log-sine and log-cosine integrals involved in more complicated integrands than those in [6], by also using the Beta function.

Recognition of Unconstrained Handwritten Digits Using Raised Cosine RBF Neural Networks (Raised Cosine RBF 신경망을 이용한 무제약 필기체 숫자 인식)

  • 박준근;김상희;박원우
    • Journal of the Institute of Convergence Signal Processing
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    • v.3 no.1
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    • pp.48-53
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    • 2002
  • In this paper, we presented a new approach to the recognition of unconstrained handwritten numerals using an improved RBF(Radial Basis Function) Neural Networks. The RBF Neural Networks used Raised Cosine as a basis function to improve discrimination and reduce processing time. The performance of Raised Cosine RBF Neural Networks classifier was evaluated using totally unconstrained handwritten numeral database of Concordia University, Montreal, Canada, and the experimental results showed the recognition rate of 98.05%.

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Modified Raised-Cosine Interpolation and Application to Image Processing (변형된 상승여현 보간법의 제안과 영상처리에의 응용)

  • 하영호;김원호;김수중
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.4
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    • pp.453-459
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    • 1988
  • A new interpolation function, named modified raised-cosine interpolation, is proposed. This function is derived from the linear combination of weighted triangular and raised-cosine functions to reduce the effect of side lobes which incur the interpolation error. Interpolation error reduces significantly for higher-order convolutional interpolation functions of linear operators, but at the expense of resolution error due to the attenuation of main lobe. However, the proposed interpolation function enables us to reduce the side lobes as well as to preserve the main lobe. To prove practicality, this function is applied in image reconstruction and enlargement.

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GEOMETRIC PROPERTIES OF STARLIKENESS INVOLVING HYPERBOLIC COSINE FUNCTION

  • Om P. Ahuja;Asena Cetinkaya;Sushil Kumar
    • Communications of the Korean Mathematical Society
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    • v.39 no.2
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    • pp.407-420
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    • 2024
  • In this paper, we investigate some geometric properties of starlikeness connected with the hyperbolic cosine functions defined in the open unit disk. In particular, for the class of such starlike hyperbolic cosine functions, we determine the lower bounds of partial sums, Briot-Bouquet differential subordination associated with Bernardi integral operator, and bounds on some third Hankel determinants containing initial coefficients.

Image Coding of Visually Weighted t Discrete Cosine Transform (시각 하중 이산여현변환 영상부호화)

  • 이문호;박주용
    • Journal of the Korean Professional Engineers Association
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    • v.22 no.2
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    • pp.19-25
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    • 1989
  • Utilizing a cosine transform in image compression has several recognized performance benefits, resulting in the ability to attain large compression ratio with small quality loss. Also, various models incorporating Human Visual System (HVS) to Discrete Cosine Trans-form (DCT) scheme are considered. Using the exact frequency components of DCT basis function, the optimum modulation transfer function (MTF) is obtained analytically. The errors at a block boundary which is important factor in transform coder are criteria for error measurement. The HVS weight coding results in perceptually higher quality images compared with the unweighted scheme.

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An Improvement of Performance for Cascade Correlation Learning Algorithm using a Cosine Modulated Gaussian Activation Function (코사인 모듈화 된 가우스 활성화 함수를 사용한 캐스케이드 코릴레이션 학습 알고리즘의 성능 향상)

  • Lee, Sang-Wha;Song, Hae-Sang
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.3
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    • pp.107-115
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    • 2006
  • This paper presents a new class of activation functions for Cascade Correlation learning algorithm, which herein will be called CosGauss function. This function is a cosine modulated gaussian function. In contrast to the sigmoidal, hyperbolic tangent and gaussian functions, more ridges can be obtained by the CosGauss function. Because of the ridges, it is quickly convergent and improves a pattern recognition speed. Consequently it will be able to improve a learning capability. This function was tested with a Cascade Correlation Network on the two spirals problem and results are compared with those obtained with other activation functions.

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