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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Journal of Korean Institute of Communications and Information Sciences
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The Korean Institute of Communications and Information Sciences
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Volume & Issues
Volume 30, Issue 12C - Dec 2005
Volume 30, Issue 12B - Dec 2005
Volume 30, Issue 12A - Dec 2005
Volume 30, Issue 11C - Nov 2005
Volume 30, Issue 11B - Nov 2005
Volume 30, Issue 11A - Nov 2005
Volume 30, Issue 10C - Oct 2005
Volume 30, Issue 10B - Oct 2005
Volume 30, Issue 10A - Oct 2005
Volume 30, Issue 9C - Sep 2005
Volume 30, Issue 9B - Sep 2005
Volume 30, Issue 9A - Sep 2005
Volume 30, Issue 8C - Aug 2005
Volume 30, Issue 8B - Aug 2005
Volume 30, Issue 8A - Aug 2005
Volume 30, Issue 7C - Jul 2005
Volume 30, Issue 7B - Jul 2005
Volume 30, Issue 7A - Jul 2005
Volume 30, Issue 6C - Jun 2005
Volume 30, Issue 6B - Jun 2005
Volume 30, Issue 6A - Jun 2005
Volume 30, Issue 5C - May 2005
Volume 30, Issue 5B - May 2005
Volume 30, Issue 5A - May 2005
Volume 30, Issue 4C - Apr 2005
Volume 30, Issue 4B - Apr 2005
Volume 30, Issue 4A - Apr 2005
Volume 30, Issue 3C - Mar 2005
Volume 30, Issue 3B - Mar 2005
Volume 30, Issue 3A - Mar 2005
Volume 30, Issue 2C - Feb 2005
Volume 30, Issue 2B - Feb 2005
Volume 30, Issue 2A - Feb 2005
Volume 30, Issue 1C - Jan 2005
Volume 30, Issue 1B - Jan 2005
Volume 30, Issue 1A - Jan 2005
Selecting the target year
A Relative Performance Comparison of Signal Detectors Based on the Correlation Information
Joo, Hyun ; Bae Jin-Soo ; Song, Iick-Ho ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 849~853
Signal detectors often utilize nonlinear statistics of observations rather than the observation as they are. The sign statistic, a typical example of the nonlinear statistics, for example, relies oかy on the sign information of observations. In this letter, a qualitative analysis is presented that the correlation coefficients between the statistics and original observations can be used to predict the asymptotic performance of a detection schemes utilizing the nonlinear statistics.
Similarity Measure Construction of the Fuzzy Set for the Reliable Data Selection
Lee Sang-Hyuk ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 854~859
We construct the fuzzy entropy for measuring of uncertainty with the help of relation between distance measure and similarity measure. Proposed fuzzy entropy is constructed through distance measure. In this study, the distance measure is used Hamming distance measure. Also for the measure of similarity between fuzzy sets or crisp sets, we construct similarity measure through distance measure, and the proposed 려zzy entropies and similarity measures are proved.
A New Production mettled of GRM coefficients using k-map
Lee Chol-U ; Che Wenzhe ; Kim Heung-Soo ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 860~870
In this paper we propose a new method to derive GRM(Generalized Reed-Muller) coefacients for each
polarities using cell of karnaugh map(k-map). Generally, there are the serial and parallel method to derive GRM coefficients. As a serial method, Green method generates GRM coefncients using transform matrix. And as a parallel method, Besslich algorithm produces GRM coefficients of each polarity using the generated anteriorly. Green's method generates GRM coefficients for n-variable by calculating transform matrix for one-variable and n-times kronecker product this matrix. And Besslich's method generates GRM coefficients of each polarity in order of Grey-code. But those methods have disadvantages that the number of variable exceeding four makes transform matrix large and there are so many operation steps. In this paper, GRM coefficients is generated by producing cell [
] minimizing variable on k-map and operating this cell [
] and transform matrix for one-variable. So, we can generate GRM coefficients of all polarities easily by using the proposed method.
An Adaptive Partial Response Equalizer Using Branch Metrics of Viterbi Trellis for Optical Recording Systems
Lee, Kyu-Suk ; Lee, Joo-Hyun ; Lee, Jae-Jin ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 871~876
In this paper, we propose an improved partial response maximum likelihood (PRML) detection scheme that has an adaptive equalizer and can be applied in the asymmetric optical recording system with high-density. We confirmed that the proposed PRML detector improves detection performance. In addition, we implemented the detector by Verilog HDL. The adaptive equalizer is composed of tap coefficient updating unit using LMS algorithn and FIR filter. FIR filter is implemented by the transposed direct form architecture for high speed operation. Viterbi detector is implemented by the register exchange method.
VQ Codebook Index Interpolation Method for Frame Erasure Recovery of CELP Coders in VoIP
Lim Jeongseok ; Yang Hae Yong ; Lee Kyung Hoon ; Park Sang Kyu ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 877~886
Various frame recovery algorithms have been suggested to overcome the communication quality degradation problem due to Internet-typical impairments on Voice over IP(VoIP) communications. In this paper, we propose a new receiver-based recovery method which is able to enhance recovered speech quality with almost free computational cost and without an additional increment of delay and bandwidth consumption. Most conventional recovery algorithms try to recover the lost or erroneous speech frames by reconstructing missing coefficients or speech signal during speech decoding process. Thus they eventually need to modify the decoder software. The proposed frame recovery algorithm tries to reconstruct the missing frame itself, and does not require the computational burden of modifying the decoder. In the proposed scheme, the Vector Quantization(VQ) codebook indices of the erased frame are directly estimated by referring the pre-computed VQ Codebook Index Interpolation Tables(VCIIT) using the VQ indices from the adjacent(previous and next) frames. We applied the proposed scheme to the ITU-T G.723.1 speech coder and found that it improved reconstructed speech quality and outperforms conventional G.723.1 loss recovery algorithm. Moreover, the suggested simple scheme can be easily applicable to practical VoIP systems because it requires a very small amount of additional computational cost and memory space.
Bayesian Network Model for Human Fatigue Recognition
Lee Young-sik ; Park Ho-sik ; Bae Cheol-soo ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 887~898
In this paper, we introduce a probabilistic model based on Bayesian networks BNs) for recognizing human fatigue. First of all, we measured face feature information such as eyelid movement, gaze, head movement, and facial expression by IR illumination. But, an individual face feature information does not provide enough information to determine human fatigue. Therefore in this paper, a Bayesian network model was constructed to fuse as many as possible fatigue cause parameters and face feature information for probabilistic inferring human fatigue. The MSBNX simulation result ending a 0.95 BN fatigue index threshold. As a result of the experiment, when comparisons are inferred BN fatigue index and the TOVA response time, there is a mutual correlation and from this information we can conclude that this method is very effective at recognizing a human fatigue.
Performance of Optimum and Suboptimum Rake Receivers in the Presence of Impulsive Noise
Kim, Byoung-Soo ; Choi, Sang-Won ; Kwon, Hyoung-Moon ; Bae, Jin-Soo ; Song, Iick-Ho ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 899~906
In this paper, the optimum maximum-likelihood rake receiver for impulsive, fading channel is derived, and a sub-optimun rake receiver with reduced complexity is obtained for practical purposes. Numerical results show that, when the noise is impulsive, the rake receivers designed for impulsive noise offer performance improvement over those optimized for Gaussian environment. It is also observed that, as the number of fingers increases, the performance of the rake receivers designed for impulsive environment improves while the rake receiver optimized for Gaussian environment experiences performance degradation in impulsive environment.
Fast computation of Observation Probability for Speaker-Independent Real-Time Speech Recognition
Park Dong-Chul ; Ahn Ju-Won ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 907~912
An efficient method for calculation of observation probability in CDHMM(Continous Density Hidden Markov Model) is proposed in this paper. the proposed algorithm, called FCOP(Fast Computation of Observation Probability), approximate obsewation probabilities in CDHMM by eliminating insignificant PDFs(Probability Density Functions) and reduces the computational load. When applied to a speech recognition system, the proposed FCOP algorithm can reduce the instruction cycles by
and can also increase the recognition speed about
while minimizing the loss in its recognition rate. When implemented on a practical cellular phone, the FCOP algorithm can increase its recognition speed about
loss in recognition rate.
A Complex Bandpass Sampling Method for Downconversion of Multiple Bandpass Signals
Bae, Jung-Hwa ; Ha, Won ; Park, Jin-Woo ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 913~921
A complex bandpass sampling technique can provide a more flexible architecture for designing a software- defined radio(SDR) system, because it has several advantageous features of larger sampling range and lower minimum sampling frequency than a real bandpass sampling method. In spite of the potential advantages of the complex bandpass sampling, solid investigation for the direct downconversion of multiple signals by the complex sampling theory has not been reported yet. Thus, we propose in this paper a novel scheme for the downconversion of multiple signals using the complex bandpass sampling, and develop the formulae related to the complex bandpass sampling for practical usage, such as the valid sampling range, the intermediate frequency (If), and the minimum sampling frequency of the downconversion of multiple RE signals. Such derived formulae are verified from simulations.
MRS Pattern Classification Using Fusion Method based on SpPCA and MLP
Song Chang kyu ; Lee Dae jong ; Jeon Byeong seok ; Ryu Jeong woong ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 922~929
In this paper, we propose the MRS p:Ittern classification techniques by the fusion scheme based on the SpPCA and MLP. A conventional PCA teclulique for the dimension reduction has the problem that it can't find a optimal transformation matrix if the property of input data is nonlinear. To overcome this drawback we extract features by the SpPCA technique which use the local patterns rather than whole patterns. In a next classification step, individual classifier based on MLP calculates the similarity of each class for local features. Finally, MRS patterns is classified by the fusion scheme to effectively combine the individual information. As the simulation results to verify the effectiveness, the proposed method showed more improved classification results than conventional methods.
Image Retrieval Using Combination of Color and Multiresolution Texture Features
Chun Young-deok ; Sung Joong-ki ; Kim Nam-chul ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 930~938
We propose a content-based image retrieval(CBIR) method based on an efncient combination of a color feature and multiresolution texture features. As a color feature, a HSV autocorrelograrn is chosen which is blown to measure spatial correlation of colors well. As texture features, BDIP and BVLC moments are chosen which is hewn to measure local intensity variations well and measure local texture smoothness well, respectively. The texture features are obtained in a wavelet pyramid of the luminance component of a color image. The extracted features are combined for efficient similarity computation by the normalization depending on their dimensions and standard deviation vectors. Experimental results show that the proposed method yielded average
better performance in precision vs. recall than the method using BDIPBVLC moments and the method using color autocorrelograrn, respectively and yielded at least
better performance than the methods using wavelet moments, CSD, color histogram. Specially, the proposed method shows an excellent performance over the other methods in image DBs contained images of various resolutions.
A Network-adaptive Context Extraction Method for JPEG2000 Using Tree-Structure of Coefficients from DWT
Choi Hyun-Jun ; Seo Young-Ho ; Kim Dong-Wook ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 939~948
In EBCOT, the context extraction process takes excessive calculation time and this paper proposed a method to reduce this calculation time. That is, if a coefficient is less than a pre-defined threshold value the coefficient and its descendents skip the context extraction process. There is a trade-off relationship between the calculation time and the image quality or the amount of output data such that as this threshold value increases, the calculation time and the amount of output data decreases, but the image degradation increases. Therefore, by deciding this threshold value according to the network environments or conditions, it is possible to establish a network-adaptive context extraction method. The experimental results showed that the range of the threshold values for acceptable image quality(better than 30dB) is from 0 to 4. The experimental results showed that in this range the Resulting reduction rate in calculation time was from
in average, the reduction rate in output data was from
in average, which means that large reduction in calculation time and output data can be obtained with a cost of an acceptable image quality degradation. Therefore, the proposed method is expected to be used efficiently in the application area such as the real-time image/video data communication in wireless environments, etc.
Content-Based Image Retrieval Using Adaptive Color Histogram
Yoo Gi-Hyoung ; Park Jung-Man ; You Kang-Soo ; Yoo Seung-Sun ; Kwak Hoon-Sung ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 949~954
From the 90's, the image information retrieval methods have been on progress. As good examples of the methods, Conventional histogram method and merged-color histogram method were introduced. Dey could get good result in image retrieval. However, Conventional histogram method has disadvantages if the histogram is shifted as a result of intensity change. Merged-color histogram, also, causes more process so, it needs more time to retrieve images. In this paper, we propose an improved new method using Adaptive Color Histogram(ACH) in image retrieval. The proposed method has been tested and verified through a number of simulations using hundreds of images in a database. The simulation results have quickly yielded the highly accurate candidate images in comparison to other retrieval methods. We show that ACH's can give superior results to color histograms for image retrieval.
A Noncoherent Method for Sequential Code Acquisition with Simplified Structure Based on Approximated Bessel Function
Kwon, Hyoung-Moon ; Lee, Ju-Mi ; Yoon, Seok-Ho ; Lee, Sung-Ro ; Song, Iick-Ho ;
The Journal of Korean Institute of Communications and Information Sciences, volume 30, issue 9C, 2005, Pages 955~963
In this paper, we consider the noncoherent code acquisition problem using sequential schemes. We show that the outputs of the noncoherent receiver approximately have a central chi-square distribution under the null hypothesis through simulations. Based on this observation, simplified acquisition schemes are obtained using the approximations of the Bessel function. The performance of the simplified and original schemes are compared in additive white Gaussian noise and slowly varying fading channels. Numerical results show that the simplified schemes have essentially the same performance as the original schemes.