• The Journal of the Acoustical Society of Korea
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• v.12 no.3
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• pp.5-12
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• 1993

볼트와 너트에 대한 초음파비파괴검사는 종파와 사각 횡파 기술을 사용하고 있는데 작은 결함신호는 자사산의 신호와 크기가 비슷해 구분이 되지 않는다. 본 논문에서는 나사산의 다중반사신호로부터 결함신호를 구분할 수 있는 방법을 제시한다. 종파를 사용하였을 경우 균열의 선단신호와 코너에서 반사되는 신호는 진행시간이 거의 같아 중첩되어 나타나지만 균열로 인한 Rayleigh파는 균열의 선단신호와 코너에서 반사되는 신호다음에 결함길이에 따른 미세한 진행시간을 가지고 나타난다. 이와는 다르게 횡파를 사용하였을때의 균열의 선단신호는 코너에서 반사되는 신호보다 앞에 나타난다. 이러한 나사산에 존재하는 결함의 선단신호를 기준으로 순방향 또는 역방향으로 반사되는 신호로부터 작은 결함신호도 구분할 수 있고 그 크기를 정량적으로 계산할 수 있다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.4
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• pp.16-23
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• 1985

In case of tissue characterization from ultrasonic echo signal, it is difficult to evaluate an absolute physical quantity because of redundancy in the echo signal. For it, in this paper a possibility of characterization of ultrasonic velocity distribution in multilayered medium using dip points analysis method from the reflected echo spectrum is discussed. To prove the possibility of this method, effect of interference phenomenon, impedance difference, attenuation, and thickness is discussed by computer simulation, and then the results confirm the effectiveness. And results of simple experiment are presented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.269-270
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• 2017

Ultrasonography of benign prostatic hypertrophy(BPH) has been used a lot to determine the size of the prostate with a biopsy. In this study, we measured the size of the prostate in a proportion of the transition zone and the peripheral zone quantitatively, we propose a method that can be diagnosed with BPH automatically ultrasound image.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.2
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• pp.138-149
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• 2000

Various modeling techniques for ultrasonic wave propagation and scattering problems in finite solid media are presented. Elastodynamic boundary value problems in inhomogeneous multi-layered plate-like structures are set up for modal analysis of guided wave propagation and numerically solved to obtain dispersion curves which show propagation characteristics of guided waves. As a powerful modeling tool to overcome such numerical difficulties in wave scattering problems as the geometrical complexity and mode conversion, the Boundary Element Method(BEM) is introduced and is combined with the normal mode expansion technique to develop the hybrid BEM, an efficient technique for modeling multi mode conversion of guided wave scattering problems. Time dependent wave forms are obtained through the inverse Fourier transformation of the numerical solutions in the frequency domain. 3D BEM program development is underway to model more practical ultrasonic wave signals. Some encouraging numerical results have recently been obtained in comparison with the analytical solutions for wave propagation in a bar subjected to time harmonic longitudinal excitation. It is expected that the presented modeling techniques for elastic wave propagation and scattering can be applied to establish quantitative nondestructive evaluation techniques in various ways.

• The Journal of the Korea Contents Association
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• v.15 no.3
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• pp.184-191
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• 2015

Prostate ultrasound is used to diagnose prostate cancer, BPH, prostatitis and biopsy of prostate cancer to determine the size of prostate. BPH is one of the common disease in elderly men. Prostate is divided into 4 blocks, peripheral zone, central zone, transition zone, anterior fibromuscular stroma. BPH is histologically transition zone urethra accompanying excessive nodular hyperplasia causes a lower urinary tract symptoms(LUTS) caused by urethral closure as causing the hyperplastic nodule characterized finding progressive ambient. Therefore, in this study normal transition zone image for hyperplasia prostate and normal transition zone image is analyzed quantitatively using a computer algorithm. We applied texture features of GLCM to set normal tissue 60 cases and BPH tissue 60cases setting analysis area $50{\times}50pixels$ which was analyzed by comparing the six parameters for each partial image. Consequently, Disease recognition detection efficiency of Autocorrelation, Cluster prominence, entropy, Sum average, parameter were high as 92~98%.This could be confirmed by quantitative image analysis to nodular hyperplasia change transition zone of the prostate. This is expected secondary means to diagnose BPH and the data base will be considered in various prostate examination.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.383-387
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• 2015

Bowel and rectal diseases are on the increase by irregular life and westernized eating habits of modern people, especially rectal cancer, which accounts for 50% of the entire colon cancer. For the initial rectal cancer, because there is no portion projecting on the surface, if not see inside the tissue with ultrasound, you make an errors that misdiagnosis as rectal abscess. However there is a need for more accurate diagnosis, because it is sometimes difficult to distinguish abscess from rectal cancer depending on staging, in spite of the ultrasonic diagnosis. Therefore, this study was performed quantitative analysis by using a computer algorithm for rectal cancer and abscess image. Each of 20 cases about normal, abscess and cancer by setting analysis region ($50{\times}50$ pixels) applies to GLCM algorithm and Autocorrelation, Max probability, Sum average, Sum variance in each image were analyzed by comparing the 4 single parameter. Consequently, The high lesion detection efficiency was presented 100% by the 3 parameter of Autocorrelation, Max probability, Sum variance and the parameter of Sum average presents 95% in cancer, more than 90% in abscess. Those parameters are valuable in distinction standard about normal, cancer and abscess in rectum. It is sufficient availability as a computer assisted diagnosis system depended on clinical using.

• The Journal of the Acoustical Society of Korea
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• v.23 no.4
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• pp.268-273
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• 2004

A method of reflection-transmission type ultrasonic inverse scattering image was presented using linearly arrayed transducers in inner surface of half-cylinder. In this method, to reduce the number of data, the mirror effect using a reflector behind object and pulse wave with finite frequency band, To verify the proposed method, a computer simulation was performed for organic phantom specimen, As the results. it was verified that the reconstructed image was satisfactory even when the limitation view angle was limited to around 30 deg.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.307-310
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• 2021

In the recent years, studies using Computer-Aided Diagnostics(CAD) have been actively conducted, such as signal and image processing technology using breast ultrasound images, automatic image optimization technology, and automatic detection and classification of breast masses. As computer diagnostic technology is developed, it is expected that early detection of cancer will proceed accurately and quickly, reducing health insurance and test ice for patients, and eliminating anxiety about biopsy. In this paper, a quantitative analysis of tumors was conducted in ultrasound images using a gray level co-occurrence matrix(GLCM) to experiment with the possibility of use for computer assistance diagnosis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.8
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• pp.1107-1113
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• 2018

Ultrasonography and photodynamic therapy have been proposed as useful tools as a treatment for inducing necrosis of cells using reactive oxygen species. Apoptosis is an internal mechanism necessary for cells regardless of damage. Ultrasound has the effect of inducing the apoptosis of these cells, and the frequency of 1 MHz is the most applicable area for medical use. The laser which is generally used in photodynamic therapy has a heat reaction and the treatment is limited. However, as a small light emitting diode is developed, it shows possibility to minimize the equipment and reduce heat reaction. On the other hand, there are relatively few researches on direct effects of light compared with studies using photosensitizers, and the area is also limited. Therefore, in this paper, we have developed a cancer cell proliferation control module using ultrasonic and light emitting diodes, which have relatively few side effects, and quantitatively analyze the effect of the module to propose an optimal suppression technique.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.502-508
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• 2012

Quantitative ultrasound technologies for osteoporosis diagnosis measure ultrasonic parameters such as speed of sound(SOS) and normalized broadband ultrasound attenuation(nBUA) in the calcaneus (heel bone). In the present study, the dependences of SOS and nBUA on bone mineral density in the proximal femur with high risk of fracture were investigated by using 20 trabecular bone samples extracted from bovine femurs. SOS and nBUA in the femoral trabecular bone samples were measured by using a transverse transmission method with one matched pair of ultrasonic transducers with a center frequency of 1.0 MHz. SOS and nBUA measured in the 20 trabecular bone samples exhibited high Pearson's correlation coefficients (r) of r = 0.83 and 0.72 with apparent bone density, respectively. The multiple regression analysis with SOS and nBUA as independent variables and apparent bone density as a dependent variable showed that the correlation coefficient r = 0.85 of the multiple linear regression model was higher than those of the simple linear regression model with either parameter SOS or nBUA as an independent variable. These high linear correlations between the ultrasonic parameters and the bone density suggest that the ultrasonic parameters measured in the femur can be useful for predicting the femoral bone mineral density.