• Tribology and Lubricants
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• 제26권6호
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• pp.341-345
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• 2010

The NAUT(Non contact Air coupled Ultrasonic Testing) is one of the ultrasonic wave inspection methods. It compensates High power ultrasound Pulser Receiver, pre-amp, air probe of high sensitivity in air to generate loss energy by NAUT methods. Generally, in case of ultrasound inspection, it applies contact methods by using couplant. However it can inspect of UT without couplant by this NAUT. The ultrasound transmission reception is composed in stable condition in NAUT. It can inspect high low material or the specimen of rough part, the narrow spot, too. The spot welding is applying the inosculation of automobile component, car body, all boards. The CFRP is necessity of NDE because of the solidity changes material according to lamella tearing. Therefore it checked on realization whether and commercialization in the spot welding and CFRP inspection that the NAUT would be applied them.

• Journal of Acupuncture Research
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• 제39권2호
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• pp.145-149
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• 2022

This study examined the effectiveness of Korean-Western cooperative treatment for patients with plantar fasciitis. Fifty patients received Korean medicine treatments (acupuncture, pharmacopuncture, herbal medicine) and Western medicine treatments (polydeoxyribonucleotide, and extracorporeal shock wave therapy). Evaluation methods used were comparison before and after ultrasound (P9), and numeric rating scale scores. Results revealed a significant improvement in the level of pain and evaluation of improvement using ultrasound. Moreover, it was suggested that Korean-Western cooperative medicine treatment may be effective for the treatment of plantar fasciitis.

• Tribology and Lubricants
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• 제30권2호
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• pp.124-129
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• 2014

The piping system accounts for a large portion of the machinery structure of a plant, and is considered as a very important mechanical structure for plant safety. Accordingly, it is used in most energy plants in the nuclear, gas, and heavy chemical industries. In particular, the piping system for a nuclear plant is generally complicated and uses the reactor and its cooling system. The piping equipment is exposed to diverse loads such as weight, temperature, pressure, and seismic load from pipes and fluids, and is used to transfer steam, oil, and gas. In ultrasound infrared thermography, which is an active thermography technology, a 15-100 kHz ultrasound wave is applied to the subject, and the resulting heat from the defective parts is measured using a thermography camera. Because this technique can inspect a large area simultaneously and detect defects such as cracks and delamination in real time, it is used to detect defects in the new and renewable energy, car, and aerospace industries, and recently, in piping defect detection. In this study, ultrasound infrared thermography is used to detect information for the diagnosis of nuclear equipment and structures. Test specimens are prepared with piping materials for nuclear plants, and the optimally designed ultrasound horn and ultrasound vibration system is used to determine damages on nuclear plant piping and detect defects. Additionally, the detected images are used to improve the reliability of the surface and internal defect detection for nuclear piping materials, and their field applicability and reliability is verified.

• Journal of Mechanical Science and Technology
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• 제16권3호
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• pp.292-301
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• 2002

Ultrasound waves interact strongly with the orientation and sequence of the plies in a layup when propagating in the thickness direction of composite laminates. Also the layup orientation greatly influences its properties in a composite laminate. If the layup orientation of a ply is misaligned, it could result in the part being rejected and discarded. Now, most researchers cut a small coupon from the waste edge and use a microscope to optically verify the ply sequences on important parts. This may add a substantial cost to the production since the test is both labor intensive and performed after the part is cured. A nondestructive technique would be very beneficial, which could be used to test the part after curing and requires less time than the optical test. Therefore we have developed, reduced, and implemented a novel ply-by-ply vector decomposition model for composite laminates fabricated from unidirectional plies. This model decomposes the transmission of a linearly polarized ultrasound wave into orthogonal components through each ply of a laminate. High probability is found, by comparisons between the model and tests, in characterizing cured layups of the laminates by using the proposed method.

• 수산해양기술연구
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• 제29권4호
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• pp.292-300
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• 1993

Acoustical imaging has made brilliant progress in the medical science field, and has also made much progress in the nondestructive testing and under water acoustics applications since doctor Dussik brother has studied about possibilities of making images of brain by recording variations in the intensity of ultrasonic beam from head in 1937. In this paper an acoustical image is reconstructed with the power spectra analysed by impulse ultrasound wave generated by electrodynamic transducer(EDT). The EDT generates the impulse ultrasound of 77KHz in center frequency and 120KHz in bandwidth at -20dB by 1200V exciter in this experiment. The impulse ultrasound has the dominant frequency components of 47KHz, 177KHz, 110KHz and 155KHz. The U shape object is adopted in making an acoustical image. The resulted spectral acoustical images are different from the optical view of the U shape object. However the image reconstructed from 110KHz spectrum is very similar to the original optical shape of the object. Even KHz level impulse sound of 70$\mu$sec pulse width is found to be useful in reconstructing acoustical imaging improvement.

• 비파괴검사학회지
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• 제32권5호
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• pp.573-584
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• 2012

유방이나 전립선과 같은 연조직에서 발생하는 암이나 종양은 주위 조직보다 단단한 경향을 가진다. 하지만 초음파 B-mode 영상을 보면 암은 주위 조직과 거의 비슷하여 구별하기 어렵다. 따라서 조직의 단단한 정도를 영상화하면 더 정량적인 정보를 제공해 진단에 도움을 줄 수 있다. 초음파탄성영상은 측정하고자 하는 연조직에 기계적인 힘을 가하고 변형된 정도를 측정하여 영상화 한다. 탄성영상은 기존의 초음파 영상 진단기법과 더불어 종양을 진단하는 유용한 방법으로 자리매김하고 있다. 본 논문에서는 지금까지 발표된 다양한 탄성영상 방법을 분류하고 각 방법의 원리, 특성 등을 살펴본다.

• 대한물리치료과학회지
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• 제14권1_4호
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• pp.11-23
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• 2007

This study was performed to evaluate the effects of low-intensity ultrasound application to the peripheral nerve injury animal model on enhancement of nerve regeneration and functional recovery. Using aseptic microsurgical techniques, the sciatic nerve of adult male Sprague-Dawley rats was crushed at the outside of right mid-thigh for 30 seconds with fine forceps. Beginning just after surgery, various continuous-wave ultrasound treatments with intensities of 0.2 W/$cm^2$, 0.5 W /$cm^2$ and 1.0 W /$cm^2$ operated at 1 MHz or sham treatment were applied to the opposite inside of the crush site for 1 minute every other day with a transducer moving speed of 2cm/sec. For evaluation of the progress of sciatic nerve regeneration, c-Fos expression in the lumbar spinal cord (L4-5) dorsal horn was investigated. c-fos expression was markedly increased at 1hour after sciatic nerve crush injury, then gradually decreased thereafter. The c-fos expressions were significantly decreased (p<0.05) in all the experimental groups in comparison with the control group until 3days post-crush, and the degrees of decrease were higher in 0.5 W/$cm^2$ and 1 W/$cm^2$ intensity ultrasound application groups. It is suggested that low-intensity ultrasound application to an animal model of sciatic crush injury may suppress pain transmission and promote nerve regeneration, and which may result in delayed progress of muscle atrophy and accelerated progress of muscle recovery and eventually may result in accelerated and improved foot function recovery.

• Clinical Endoscopy
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• 제56권2호
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• pp.185-187
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• 2023

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.213-214
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• 1998

The important role of the ultrasonic Doppler system in the modem clinical medicine is to provide the clinical information of the vascular system. The ultrasonic pulsed wave(PW) Doppler system, a kind of the ultrasound Doppler system, is more available than the ultrasonic continuous wave(CW) Doppler system because it can evaluate the velocity and the direction of blood flow as well as the depth of vessel. However, the ultrasonic PW Doppler system has the disadvantage that the range of evaluating velocity of blood flow is limited(Nyquist limit). In order to solve this limit, we propose the algorithm for eliminating this aliasing in this paper. In addition, we propose the efficient signal processing algorithm.

• Korean Journal of Radiology
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• 제22권11호
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• pp.1841-1849
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• 2021

Objective: To prospectively investigate the feasibility of shear wave elastography (SWE) as a new quantitative and objective method for evaluating the stiffness of the gastrocnemius medialis (GM) muscle during passive stretching in patients with Parkinson's disease (PD). Materials and Methods: SWE of the GM muscle was performed in 28 patients with PD [13 female and 15 male; mean age ± standard deviation (SD): 63.0 ± 8.5 years] and 12 healthy controls (5 female and 7 male; mean age ± SD: 59.3 ± 6.4 years) during passive ankle rotation. A Young's modulus-ankle angle curve was constructed. The GM slack angle and baseline Young's modulus (E₀) were compared between the markedly symptomatic and mildly symptomatic sides of patients with PD, and healthy controls. Additionally, the correlation between the GM slack angle and the severity of rigidity, and the observer reproducibility of SWE in determining the GM slack angle were evaluated. Results: The GM slack angle was smaller on both the markedly and mildly symptomatic sides in patients with PD than in healthy controls (mean ± SD of -29.13° ± 3.79° and -25.65° ± 3.39°, respectively, vs. -21.22° ± 3.52°; p < 0.001 and p = 0.006, respectively). Additionally, in patients with PD, the GM slack angle on the markedly symptomatic side was smaller than that on the mildly symptomatic side (p = 0.003). The E0 value was lower on both the markedly and mildly symptomatic sides in patients with PD than in healthy controls (mean ± SD of 10.11 ± 2.85 kPa and 10.08 ± 1.88 kPa, respectively, vs. 12.23 ± 1.02 kPa; p = 0.012 and p < 0.001, respectively). However, no significant difference was found between the markedly and mildly symptomatic sides in patients with PD (p = 0.634). A negative linear relationship was observed between the GM slack angle and lower limb rigidity score on the markedly symptomatic side in patients with PD (r = -0.719; p < 0.001). The intraclass correlation coefficients for observer reproducibility of SWE ranged from 0.880 to 0.951. Conclusion: The slack angle determined by SWE may be a useful quantitative and reproducible method for evaluating muscle stiffness in patients with PD.