• Title/Summary/Keyword: S-Transform

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SOME BILINEAR ESTIMATES

  • Chen, Jiecheng;Fan, Dashan
    • Journal of the Korean Mathematical Society
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    • v.46 no.3
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    • pp.609-620
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    • 2009
  • We establish some estimates on the hyper bilinear Hilbert transform on both Euclidean space and torus. We also use a transference method to obtain a Kenig-Stein's estimate on bilinear fractional integrals on the n-torus.

SOME THEOREMS ON GENERALISED MEIJER TRANSFORM

  • Bora, S.L.
    • Kyungpook Mathematical Journal
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    • v.12 no.1
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    • pp.55-60
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    • 1972
  • In this paper two theorems on generalised Meijer transform due to Banerjee [1, p. 433] defined by $${\varphi}_1(p)=\int\limits_{0}^{\infty}(2px)^{m-{\frac{1}{2}}_e-{\frac{1}{2}}pxn}{\varphi}({{\alpha},c;\;2px)f(x)dx$$, have been proved. Some interesting integrals involving hyper-geometric functions are evaluated by the application of theorems.

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Autonomous Traveling of Unmanned Golf-Car using GPS and Vision system (GPS와 비전시스템을 이용한 무인 골프카의 자율주행)

  • Jung, Byeong Mook;Yeo, In-Joo;Cho, Che-Seung
    • Journal of the Korean Society for Precision Engineering
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    • v.26 no.6
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    • pp.74-80
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    • 2009
  • Path tracking of unmanned vehicle is a basis of autonomous driving and navigation. For the path tracking, it is very important to find the exact position of a vehicle. GPS is used to get the position of vehicle and a direction sensor and a velocity sensor is used to compensate the position error of GPS. To detect path lines in a road image, the bird's eye view transform is employed, which makes it easy to design a lateral control algorithm simply than from the perspective view of image. Because the driving speed of vehicle should be decreased at a curved lane and crossroads, so we suggest the speed control algorithm used GPS and image data. The control algorithm is simulated and experimented from the basis of expert driver's knowledge data. In the experiments, the results show that bird's eye view transform are good for the steering control and a speed control algorithm also shows a stability in real driving.

THE HARMONIC ANALYSIS ASSOCIATED TO THE HECKMAN-OPDAM'S THEORY AND ITS APPLICATION TO A ROOT SYSTEM OF TYPE BCd

  • Trimeche, Khalifa
    • Korean Journal of Mathematics
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    • v.27 no.1
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    • pp.221-267
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    • 2019
  • In the five first sections of this paper we define and study the hypergeometric transmutation operators $V^W_k$ and $^tV^W_k$ called also the trigonometric Dunkl intertwining operator and its dual corresponding to the Heckman-Opdam's theory on ${\mathbb{R}}^d$. By using these operators we define the hypergeometric translation operator ${\mathcal{T}}^W_x$, $x{\in}{\mathbb{R}}^d$, and its dual $^t{\mathcal{T}}^W_x$, $x{\in}{\mathbb{R}}^d$, we express them in terms of the hypergeometric Fourier transform ${\mathcal{H}}^W$, we give their properties and we deduce simple proofs of the Plancherel formula and the Plancherel theorem for the transform ${\mathcal{H}}^W$. We study also the hypergeometric convolution product on W-invariant $L^p_{\mathcal{A}k}$-spaces, and we obtain some interesting results. In the sixth section we consider a some root system of type $BC_d$ (see [17]) of whom the corresponding hypergeometric translation operator is a positive integral operator. By using this positivity we improve the results of the previous sections and we prove others more general results.

Nondestructive Evaluation by Joint Time-Frequency Analysis of Degraded SUS 316 Steel (열화된 SUS 316강의 시간-주파수 해석에 의한 비파괴평가)

  • Lee, Kun-Chan;Oh, Jeong-Hwan;Nam, Ki-Woo;Lee, Joo-Suk
    • Journal of the Korean Society for Nondestructive Testing
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    • v.19 no.4
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    • pp.270-276
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    • 1999
  • Fourier transform has been one of the most commonly used tools in study of frequency characteristics of signal. However, based on the Fourier transform. it is hard to tell whether a signal's frequency contents evolve in time or not. Recently, to overcome Fourier transform fault. not to represent non-stationary signal, time-frequency analysis methods are developed and those can represent informations of signal's time and frequency at the same time. In this study we analysed ultrasonic signal for degraded SUS 316 with time-frequency analysis method. In particular the methods such as short time Fourier(STFT) and Wigner-Ville distribution(WVD) were used to extract frequency contents and characteristics from ultrasonic signals.

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Blind Video Fingerprinting Using Temporal Wavelet Transform (시간축 웨이블릿 변환을 이용한 블라인드 비디오 핑거프린팅)

  • Kang Hyun-Ho;Park Ji-Hwan;Lee Hye-Joo;Hong Jin-Woo
    • Journal of Korea Multimedia Society
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    • v.7 no.9
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    • pp.1263-1272
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    • 2004
  • In this paper, we present a novel video fingerprinting implementation method to identify the source of illegal copies. The video fingerprinting is achieved by the insertion of uniform distributed random number is made by seller and buyer's identification key-in the video wavelet coefficients by their temporal wavelet transform. The proposed fingerprinting is able to detect unique fingerprint of video contents even if they have been distorted by collusion attacks and MPEG2 compression. Especially, we use characteristics of the temporal wavelet transform to assign user's embedding area. Experimental results show the traceability of unauthorized distribution of video contents and its robustness to various collusion attacks and MPEG2 compression.

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Design of PC-based CR-PACS using Multiresolution Wavelet Transform (다해상도 웨이블릿 변환을 이용한 PC기반의 CR-PACS 설계)

  • 김광민;유선국
    • Journal of Biomedical Engineering Research
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    • v.19 no.3
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    • pp.305-312
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    • 1998
  • A small PACS based on PC is designed for CR. To receive the digital image from CR, a DICOM Interface Unit (DIU) is designed that complied with the medical image standard, DICOM V3.0. The CR images acquired through the DIU are stored in a file-server; the patient information of the images is stored in a database. To improve the performance of PC and to use it easily, multiresolution images are constructed by wavelet transform and displayed progressively. Wavelet compression method is newly adopted to store the images hierarchically to storage units. In this compression method, the image is decomposed into subclasses of image by wavelet transform, and then the subclasses of the image are vector quantized using a multiresolution codebook. The storage units for CR images were divided into the short-term storage in file-server and the harddisk in viewing station. Image processing tools supported by general PACS is implemented based on PC.

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Implementation of Spectrum Sensing Module using STFT Method (STFT 기법을 적용한 스펙트럼 센싱 모듈 구현)

  • Lee, Hyun-So;Kang, Min-Kyu;Moon, Ki-Tak;Kim, Kyung-Seok
    • The Journal of the Korea Contents Association
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    • v.10 no.1
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    • pp.78-86
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    • 2010
  • The Spectrum Sensing Technology is the core technology of the Cognitive Radio (CR) System that is one of the future wireless communication technologies. In this paper, we proposed the efficient Spectrum Sensing Method using the Short Time Fourier Transform (STFT) that is the algorithm for Time-Frequency analysis of the raw data. Applied window function to STFT algorithm is a Kaiser window, it is piled up its 50% range. For the simulation, the DVB-H signal with the 6MHz bandwidth is used as the Input Signal. And we confirm the Spectrum Sensing result using Modified Periodogram Method, Welch's Method for compared with Short Time Fourier Transform Algorithm. And also, Spectrum Sensing Module is implemented using embedded board.

Scalable Video Coding with Low Complex Wavelet Transform (공간 웨이블릿 변환의 복잡도를 줄인 스케일러블 비디오 부호화에 관한 연구)

  • Park Seong-Ho;Jeong Se-Yoon;Kim Won-Ha
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.42 no.3 s.303
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    • pp.53-62
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    • 2005
  • In the decoding process of interframe Wavelet coding, the Wavelet transform requires huge computational complexity. Since the decoder may need to be used in various devices such as PDAs, notebooks, or PC, the decoder's complexity should be adapted to the processor's computational power. So, it is natural that the low complexity codec is also required for scalable video coding. In this paper, we develop a method of controlling and lowering the complexity of the spatial Wavelet transform while sustaining the same coding efficiency as the conventional spatial Wavelet transform. In addition, the proposed method may alleviate the ringing effect for slowly changing image sequences.