• Journal of the Korean Statistical Society
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• v.23 no.2
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• pp.303-323
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• 1994

In this paper, distribution of Votaw's $\lambda_1$(mvc) criterion has been obtained using inverse Mellin transform, residue theorem and properties of special functions.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.9
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• pp.30-40
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• 2014

As the Hadamard transform can be generalized into the Jacket transform, in this paper, we generalize the Haar transform into the Jacket-Haar transform. The entries of the Jacket-Haar transform are 0 and ${\pm}2^k$. Compared with the original Haar transform, the basis of the Jacket-Haar transform is general and more suitable for signal processing. As an application, we present the DCT-II(discrete cosine transform-II) based on $2{\times}2$ Hadamard matrix and HWT(Haar Wavelete transform) based on $2{\times}2$ Haar matrix, analysis the performances of them and estimate them via the Lenna image simulation.

• The Journal of the Acoustical Society of Korea
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• v.26 no.5
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• pp.214-219
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• 2007

This paper proposes a new IFFT(Inverse Fast Fourier Transform) algorithm, which is proper for IMDCT(Inverse Modified Discrete Cosine Transform) of MPEG-2 AAC(Advanced Audio Coding) decoder. The $2^n$(N-point) type IMDCT is the most powerful among many IMDCT algorithms, however it includes IFFT that requires many calculation cycles. The IFFT used in $2^n$(N-point) type IMDCT employ the bit-reverse data arrangement of inputs and N/4-point complex IFFT to reduce the calculation cycles. We devised a new data arrangement method of IFFT input and $N/4^{n+1}$-type IFFT and thus we can reduce multiplication cycles, addition cycles, and ROM size.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.3
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• pp.184-191
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• 2018

Orthogonal frequency division multiplexing(OFDM) is a multicarrier modulation(MCM) system that enables high-speed communications using multiple carriers and has advantages of power and spectral efficiency. Therefore, this study aims to complement the existing shortcomings and to design an efficient MCM system. The proposed system uses the inverse discrete wavelet transform(IDWT) operation instead of the inverse fast Fourier transform(IFFT) operation. The bit error rate(BER), spectral efficiency, and peak-to-average power ratio(PAPR) performance were compared with the conventional OFDM system through the OFDM system design based on wavelet transform. Our results showed that the conventional OFDM and Wavelet-OFDM exhibited the same BER performance, and that the Wavelet-OFDM using the discrete Meyer wavelet had the same spectral efficiency as the conventional OFDM. In addition, all systems of Wavelet-OFDM based on various wavelets confirm a PAPR performance lower than that of conventional OFDM.

• Journal of IKEEE
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• v.17 no.4
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• pp.570-578
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• 2013

This paper proposed an $8{\times}8$ HEVC inverse core transform architecture reusing multipliers. In HEVC core transform, processing of lower size block is identical with even part of upper size block. So an $8{\times}8$ core transform architecture can process both $8{\times}8$ and $4{\times}4$ core transforms. However, when $8{\times}8$ core transform architecture is exploited, frame processing time doubles in $4{\times}4$ core transform, since $8{\times}8$ and $4{\times}4$ core transforms concurrently process 8 and 4 pixels, respectively. In this paper, a novel inverse core transform architecture is proposed based on multiplier reuse. It runs as an $8{\times}8$ inverse core transformer or two $4{\times}4$ inverse core transformer. Its frame processing time is same in $8{\times}8$ and $4{\times}4$ core transforms, and reduces gate counts by 12%.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2253-2260
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• 2012

In this paper, an efficient hardware architecture is proposed for inverse transform and inverse quantization of H.264/AVC decoder. The previous inverse transform and quantization architecture has a different AC and DC coefficients decoding order. In the proposed architecture, IQ is achieved after IT regardless of the DC or AC coefficients. A common operation unit is also proposed to reduce the computational complexity of inverse quantization. Since division operation is included in the previous architecture, it will generate errors if the processing order is changed. In order to solve the problem, the division operation is achieved after IT to prevent errors in the proposed architecture. The architecture is implemented with 3-stage pipeline and a parallel vertical and horizontal IDCT is also implemented to reduce the operation cycle. As a result of analyzing the proposed ITIQ architecture operation cycle for one macroblock, the proposed one has improved by 45% than the previous one.

• The Journal of the Acoustical Society of Korea
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• v.23 no.1E
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• pp.3-9
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• 2004

An important inverse problem in the field of acoustics is that of reconstructing the strengths of a number of sources given a model of transmission paths from the sources to a number of sensors at which measurements are made. In dealing with this kind of the acoustical inverse problem, strengths of the discretised source distribution can be simply deduced from the measured pressure field data and the inversion of corresponding matrix of frequency response functions. However, deducing :he solution of such problems is not straightforward due to the practical difficulty caused by their inherent ill-conditioned behaviour. Therefore, in order to overcome this difficulty associated with the ill-conditioning, the problem is replaced by a nearby well-conditioned problem whose solution approximates the required solution. In this paper a microphone array are identified for which the inverse problem is optimally conditioned, which can be robust to contaminating errors. This involves sampling both source and field in a manner which results in the discrete pressures and source strengths constituting a discrete Fourier transform pair.

• Journal of the Korean Society of Safety
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• v.22 no.4
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• pp.13-19
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• 2007

An numerical method to estimate thermal diffusivity has been developed for one-dimensional unsteady heat conduction problem, when the temperatures are know at two positions in a semi-infinite body. Using the closed form solution which has already derived an explicit solution for the inverse problem for one-dimensional transient heat conduction using Laplace transform technique, we first estimate the surface temperature. The thermal diffusivity can be estimated by using the estimated surface temperature and measured temperatures, which include some uncertainties. The estimated surface heat flux and thermal diffusivity are found to be in good agreement with those of the experimented conditions. This method will be extended to the simultaneous measurement of thermal diffusivity and thermal conductivity.

• The Mathematical Education
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• v.24 no.1
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• pp.25-29
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• 1985

• The Journal of the Acoustical Society of Korea
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• v.31 no.5
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• pp.332-339
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• 2012

Beamspace transform algorithm transforms spatial-domain data - such as x, y, z dimension - into incidence-angle-domain data, which is called beamspace-domain data. The beamspace transform method is generally used in source localization and tracking, and adaptive beamforming problem. When the beamspace transform method is used in multichannel audio source separation, the inverse beamspace transform is also important because the source image have to be reconstructed. This paper studies the beamspace transform and inverse transform algorithms for multichannel audio source separation system, especially for the beamspace-domain multichannel NMF algorithm.