• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.5
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• pp.369-377
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• 1999

Recently, it is gradually raised necessity that thickness of thin film is measured accuracy and managed in industrial circles and medical world. Ultrasonic signal processing method is likely to become a very powerful method for NDE method of detection of microdefects and thickness measurement of thin film below the limit of ultrasonic distance resolution in the opaque materials, provides useful information that cannot be obtained by a conventional measuring system. In the present research. considering a thin film below the limit of ultrasonic distance resolution sandwiched between three substances as acoustical analysis model, demonstrated the usefulness of ultrasonic signal processing technique using information of ultrasonic frequency for NDE of measurements of thin film thickness. Accordingly, for the detection of delamination between the junction condition of boundary microdefect of thin film sandwiched between three substances the results from digital image processing.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.2
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• pp.128-133
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• 2015

This paper describes the construction of a static 3D ultrasonography image by tracking the radiation beam position during the handy operation of a 1D array probe to enable point-of-care use. The theoretical model of the transformation from the translational and rotational information of the sensor mounted on the probe to the reference Cartesian coordinate system was given. The signal amplification and serial communication interface module was made using a commercially available sensor. A test phantom was also made using silicone putty in a donut shape. During the movement of the hand-held probe, B-mode movie and sensor signals were recorded. B-mode images were periodically selected from the movie, and the gray levels of the pixels for each image were converted to the gray levels of 3D voxels. 3D and 2D images of arbitrary cross-section of the B-mode type were also constructed from the voxel data, and agreed well with the shape of the test phantom.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.3
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• pp.316-322
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• 2014

A movie recommendation system is proposed to learn a preference model of a viewer by using multimodal features of a video content and their evoked implicit responses of the viewer in synchronized manner. In this system, facial expression, body posture, and physiological signals are measured to estimate the affective states of the viewer, in accordance with the stimuli consisting of low-level and affective features from video, audio, and text streams. Experimental results show that it is possible to predict arousal response, which is measured by electrodermal activity, of a viewer from auditory and text features in a video stimuli, for estimating interestingness on the video.

• The Journal of the Acoustical Society of Korea
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• v.11 no.3
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• pp.5-13
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• 1992

Taking devantage of the property that Korean digit is a mono-syllable word, we proposed a spoken Korean-digit recognition scheme using the multi-layer perceptron. The spoken Korean-digit is divided into three segments (initial sound, medial vowel, and final consonant) based on the voice starting / ending points and a peak point in the middle of vowel sound. The feature vectors such as cepstrum, reflection coefficients, ${\Delta}$cepstrum and ${\Delta}$energy are extracted from each segment. It has been shown that cepstrum, as an input vector to the neural network, gives higher recognition rate than reflection coefficients. Regression coefficients of cepstrum did not affect as much as we expected on the recognition rate. That is because, it is believed, we extracted features from the selected stationary segments of the input speech signal. With 150 ceptral coefficients obtained from each spoken digit, we achieved correct recognition rate of 97.8%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10C
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• pp.965-974
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• 2007

In this paper, we proposed the feature selection algorithm for multi-class genre classification. In our proposed algorithm, we developed GMM separation score based on Gaussian mixture model for measuring separability between two genres. Additionally, we improved feature subset selection algorithm based on sequential forward selection for multi-class genre classification. Instead of setting criterion as entire genre separability measures, we set criterion as worst genre separability measure for each sequential selection step. In order to assess the performance proposed algorithm, we extracted various features which represent characteristics such as timbre, rhythm, pitch and so on. Then, we investigate classification performance by GMM classifier and k-NN classifier for selected features using conventional algorithm and proposed algorithm. Proposed algorithm showed improved performance in classification accuracy up to 10 percent for classification experiments of low dimension feature vector especially.

• Journal of the Institute of Convergence Signal Processing
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• v.4 no.1
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• pp.1-8
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• 2003

Various methods have been studying to maintain and apply the multimedia inform abruptly increasing over all social fields, in recent years. For retrieval of still images, we is implemented content-based image retrieval system in this paper that make possible to retrieve similar objects from image database after segmenting query object from background if user request query. Query image is processed median filtering to remove noise first and then object edge is detected it by canny edge detection. And query object is segmented from background by using convex hull. Similarity value can be obtained by means of histogram intersection with database image after securing color histogram from segmented image. Also segmented image is processed gray convert and wavelet transform to extract spacial gray distribution and texture feature. After that, Similarity value can be obtained by means of banded autocorrelogram and energy. Final similar image can be retrieved by adding upper similarity values that it make possible to not only robust in background but also better correct object retrieval by using object segmentation method.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.1
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• pp.19-25
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• 2010

In this paper, digital watermarking method using quad-tree algorithm is proposed. The proposed algorithm searches the significant coefficient of the watermark by using quad-tree algorithm and inserts the watermark by the Cox's algorithm. The simulation for performance analysis of the proposed algorithm is implemented about the effect of quad-tree algorithm in wavelet domain and that of embedding watermark in each subband coefficient (HH, LH, HL) and each DWT level, and that of embedding in the lowest frequency band (LL). As a simulation result, digital watermarking using quad-tree algorithm improves the watermarking performance in comparison with inserting watermark in the significant coefficients of fixed frequency band. The watermarking performance of simultaneously embedding in HH, LH, and HL band of DWT(6 level) is better than that of different cases. In addition, insertion the watermark to the LL band about 30~60% of all watermarks improves the correlation value while PSNR performance decreases 1~3dB.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.1
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• pp.27-32
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• 2013

It plays an important role to detect the shape of an ellipse in many application areas of image processing. But it is very difficult to detect the ellipse in the real image because the noise was involved in the image, other objects obscured the ellipse or the ellipses were overlap with each other. In this paper, we extract the boundary (edge) to detect ellipse in the image and perform the grouping process in order to reduce amount of information. As a result, the speed of the ellipse detection was improved. Also in order to the ellipse detection, we selected the five ellipse parameters at random And then to select the optimal parameters of the ellipse, the linear least-squares approximation is applied. To verify the ellipse detection, RANSAC algorithm is applied. After the algorithm proposed in this study was implemented, the results applied to the real images showed an aocuracy of 75% and speed was very fast to compared with other researches. It mean that the proposed algorithm was valuable to detect the ellipses in the image.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.2
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• pp.112-120
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• 2008

This study aims to develop a system for diagnosing pulse and disease conditions based on oriental medical classics to collect objective quantitative information in the traditional pulse examination environment that uses fingers. For this purpose, the study suggested a thimble-type sensor unit as the most appropriate pulse analyzer and proposed a traditional method to measure the pulse pressure wave on the spots of cheok, gwan and chon by installing the pulse analyzer on the forefinger, middle finger and medical finger. Then, it was interpretively found that this pulse analyzer enables us to objectively recognize 28 pulses defined in Oriental medical classics including the yukjo pulse, described as the buchimjisak-heosil pulse, and the hong, yoo, hyeok and san pulses. Finally, the study proposed a method to extract key parameters essential to pulse condition diagnosis from the pulse pressure wave measured by this pulse analyzer.

• Journal of the Institute of Convergence Signal Processing
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• v.19 no.3
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• pp.110-117
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• 2018

The development of prosthetic hand or prosthetic leg equipment is steadily taking place globally. Though it would be difficult to create or feel the same way as a human hand, it would be a great for the amputated person if they can pick things up or do some movement as they want. It has become possible to develop low-cost prosthetic hand according to development of 3D printing technology. If people can develop personalized prosthetic equipment at similar prices to meet this trend, the utilization and penetration rate will be much higher. In this study, it describes how to develop a user-customizable prosthetic hand using 3D printing. To do this, the transformational parameters of prosthetic hand shape modeling are extracted as variability values, and the functions for controlling prosthetic hand motion are designed as software design patterns. This allows people who need a prosthetic hand to have their own prosthetic hand at a fast and affordable price.