• Journal of the Korea Society of Computer and Information
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• v.18 no.12
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• pp.21-26
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• 2013

In this paper, We are suggested methods of feature extraction in molecular images. The result of image transform DWT examination by suggested method, we are obtained as follows. 1-level and 2-levels of decomposition results showed the composition of the low frequency region. But, 3-level decomposition results did not appear in the data component is almost. Observed not with the naked eye is not, but the 3-level output data values of the results were decomposed. We are printed the horizontal and vertical directions of low-frequency region of the data, the high frequency region of the horizontal and vertical data, and diagonal high frequency region of the horizontal and vertical directions data. If the output data using molecular imaging and CT, PET, MR imaging will be compared with the data.

• The Journal of the Acoustical Society of Korea
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• v.16 no.4
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• pp.5-10
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• 1997

In this paper, a new time delay estimation algorithm, WTD-LMSTDE was proposed. This method has great improvement in convergence rate relative to the time domain approach by decreasing the eigen value spread of input signal autocorrelation matrix. The performance of the algorithm was evaluated for the cases of time invariant time delay and time varying time delay. In the case of time invariant time delay, the estimation accuracy of WTD-LMSTDE was better than that of LMSTDE from 3.3% to 12.5% with respect to SNR. In the case of time varying time delay, the mean error power of WTD-LMSTDE in linear increased delay environment was decreased about 2.4dB compared to that of LMSTDE under noise-free condition. As a result, we showed that the performance of WTD-LMSTDE is better than of LMSTDE.

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.155-158
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• 2000

In this paper, the quantization noise in block-based video coding is analyzed, and a post-processing method based on the analysis is presented for reducing the quantization noise by using a wavelet transform(WT). In the proposed method, the quantization noise is considered as the sum of a blocking noise expressed as a deterministic profile and the random remainder noise. Each noise is removed in a viewpoint of image restoration using a 1-D WT, which yields a regularized differentiation. The blocking noise first is reduced by weakening the strength of each blocking noise component that appears as an impulse in the first scale wavelet domain. The impulse strength estimation is performed using median filter, quantization parameter(QP), and local activity. The remainder noise, which is considered as a white noise at non-edge pixels, then is reduced by soft-thresholding. The experimental results show that the proposed method yields better performance in terms if subjective quality as well as PSNR performance over VM post-filter in MPEG-4 for all test sequences of various compression ratios. We also present a fast post-processing in spatial domain equivalent to that in wavelet domain for real-time application.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.7
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• pp.102-111
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• 1997

In this paper, a patern recognition method of surface mount device(SMD) IC using wavelet transform and neural network is proposed. We chose the feature parameter according to the characteristics of coefficient matrix which is obtained from four level discrete wavelet transform (DWT). These feature parameters are normalized and then used for the input vector of neural network which is capable of adapting the surroundings such as variation of illumination, arrangement of objects and translation. Experimental results show that when the same form of feature pattern, as is used for learning, is put into neural network and gained 100% rate ofrecognition irrespective of SMD IC kinds, location and variation of illumination. In the case of unused feature pattern for learning, the recognition rate is 85.9% under the similar surroundings, where as an average recognition rate is 96.87% for the case of reregulated value of illumination. Proosed method is relatively simple compared with the traditional space domain method in extracting the feature parameter and is also well suited for recognizing the pattern's class, position and existence. It can also shorten the processing tiem better than method extracting feature parameter with the use of discrete cosine transform(DCT) and adapt the surroundings such as variation of illumination, the arrangement and the translation of SMD IC.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.1
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• pp.1-9
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• 2009

In this paper, proposed digital image watermarking technique with lifting wavelet transformation. This watermark technique can be easily extended in video content fields. Therefore, we apply this watermark technique to layered depth image structure that is efficient compression method of multi-view video with depth images. This application steps are very simple, because watermark is inserted only reference image. And watermarks of the other view images borrow from reference image. Each view image of multi-view video may be guaranteed authentication and copyright.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.1
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• pp.44-49
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• 2002

In recent years, diagnostic techniques have been investigated to detect a partial discharge(PD) in a high voltage electrical equipment. Because PD signal is very sensitive and difficult to suppress strong noises such as narrow-band radio frequency noise and random noise, the accuracy and credibility of PD measurement might be influenced by surrounding interference. Using the technique of PD detection by electromagnetic wave, we have studied the characteristics of both PD and substation-in interference signal. Also, we propose a wavelet packet transform based technique to perform a feature extraction from the interference and PD signal and a classification of the extracted features. The results show that time-frequency characteristics between PD and interference can be obviously distinguished. It is helpful for the development of the insulation diagnosis technique.

• Journal of the Korea Computer Industry Society
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• v.2 no.8
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• pp.1117-1122
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• 2001

Recently, issues on the internet searching of image information through various multimedia databases have drawn an tremendous attention and several researches on image information retrieval methods are on progress. By incorporating wavelet transform and correlation matrixes, we propose a novel and highly efficient feature vector extraction algorithm that has an capability of a robust similarity matching. The simulation results have yielded a faster and highly accurate candidate image retrieval performance in comparison to those of the conventional algorithms. Such an improved performance can be obtained because the used feature vectors were compressed to 256：1 while the correlation matrixes are incorporated to provide a fuel information for the better matching.

• The Journal of Information Technology
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• v.10 no.3
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• pp.15-31
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• 2007

Region-of-Interest is the region within the image selected for the users needs. The development of multimedia has made the expectation of image telecommunication higher, but the usage of the image, image transmission time, and image storage create problems. When transmitter or the receiver stops transmission at some point, we can still see the general image and the ROI maintains better image quality if the ROI is specified beforehand. In this paper, three methods are proposed and constructed for the transmission of ROI. In the first method, the ROI and the background are separated and then encoded as described above. The second method is to encode without separating the ROI and the background. The masked region is scaled and the coefficients are increased, then the region is transmitted first. The third method is the loseless coding of the ROI. For loseless coding, real number tap cannot be restored perfectly due to the rounding error, so the method of using integers is used. The proposed method shows a better performance than EZW even in case of ROI's PSNR at quality of 40 dB.

• Journal of KSNVE
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• v.9 no.4
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• pp.841-848
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• 1999

In the quality assurance check process of DC motor systems, even though the overall sound pressure level is acceptable, there is an incident that subjective evaluation leads to failure in product quality due to annoying noise. This kind of problem may be originated from the manufacturing or assembly process. In this paper, the transient spectral analysis, or the time-frequency analysis is applied to the noise quality problem. For the case study, the cause of annoying noise in the wind shield wiper motor is experimentally analyzed in detail. It is concluded that the defect in the shaft causes the impact noise which is not detectable by steady spectral analysis. Also demonstrated is how the time-frequency analysis is effectively applied to the annoying noise identification of the rotor-gear system.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.9
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• pp.425-432
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• 2000

Wavelet transform is a new method fro electric power quality analysis. Several types of mother wavelets are compared using voltage sag data. Investigations on the use of some mother wavelets, namely Daubechies, Symlets, Coiflets, Biorthogonal, are carried out. On the basis of extensive investigations, optimal mother wavelets for the detection of voltage sag are chosen. The recommended mother wavelet is 'Daubechies 4(db4)' wavelet. 'db4', the most commonly applied mother wavelet in the power quality analysis, can be used most properly in disturbance phenomena which occurs rapidly for a short time. This paper presents a discrete wavelet transform approach for determining the beginning time and end time of voltage sags. The technique is based on utilising the maximum value of d1(at scale 1) coefficients in multiresolution analysis(MRA) based on the discrete wavelet transform. The procedure is fully described, and the results are compared with other methods for determining voltage sag duration, such as the RMS voltage and STFT(Short-Time Fourier Transform) methods. As a result, the voltage sag detection using wavelet transform appears to be a reliable method for detecting and measuring voltage sags in power quality disturbance analysis.