• Journal of Digital Convergence
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• v.10 no.11
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• pp.459-465
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• 2012

This study has investigated the effect of isometric contractile force and muscle activity applying ice and hot according to the time from the biceps brachii muscle. In this study, 20 university students participants without musculoskeletal and neurological disorders. By applying a hot pack 5 min, 10 min, 20 min and 30 min respectively and ice pack for 5 min, 10 min, and 20 min respectively. After that measurement are skin temperature, contractile force and muscle activity. Skin temperature of the hot and cold 5 min applied that rapidly changing. Increasing the time it takes to apply a variance has been reduced(p<.001). Isometric contractile force was not statistically significant but highest when applying the hot pack 5 minutes and lowest when applying the hot pack 30 minutes(p<.001). Muscle activity and median frequency was highest when applying the hot pack 5 minutes. To analyze the above results, it was found that isometric contractile force and muscle activity changed according to the applying time. These result lead us to the conclusion that this study will be more evidence for changes in muscle contraction to apply hot pack and ice pack on clinic.

• Geophysics and Geophysical Exploration
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• v.15 no.4
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• pp.199-208
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• 2012

High-amplitude swell noises (HASN) are very difficult to eliminate from the marine seismic data. In this paper, we applied F-X filter and median filter in order to suppress HASN. Test data have been acquired on the northern offshore of the South Shetland Islands in December, 2010. Parts of data have been contaminated by HASN caused by bad weather during the cruise. We applied F-X filter and median filter to test data with HASN. After F-X filtering, most of non-coherent noises and small-amplitude swell noises are eliminated effectively but HASN are still remained significantly. With median filter, HASN was suppressed better than F-X filter, however some of non-coherent noises are still remains. We applied a cascade of two filters and results show HASN and non-coherent noises are suppressed effectively. After the cascade of two filtering, it is possible to define reflection layers clearly on the velocity spectrum and to produce better stacked section with a good signal-to-noise ratio.

• The Journal of the Korea Contents Association
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• v.13 no.2
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• pp.1-7
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• 2013

This study was aimed to evaluate the characteristics of impact sound of golf driver according to impact points of its face. In order to get the consistent impact sounds, the apparatus for free golf ball drop was prepared and used. Timed amplitude patterns and maximum spectral peaks of the impact sounds were variant according to the impact points of driver face. As an alternative method of impact sound analysis, cumulative sum of spectral power (cumsum) was used to distinguish between impact sounds according to the impact positions. From the comparison of frequencies representing 20%, 40%, 60%, 80% of cumsum of impact sound, 40% cumsum frequency of the center of driver face was lower than that of the toe and the heel. This finding suggests that the impact sound from the center of driver face has higher spectral power of low frequency component than that of the toe and heel.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.1
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• pp.143-152
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• 2001

A method for miniaturization of microstrip patch antenna without degrading its radiation characteristics is investigated in this paper. It involves perforating the patch to form a microstrip square-ring antenna, and it's BW enhancement is investigated numerically and experimentally. A ring geometry introduces additional parameters to the antenna, and those are used to control impedances, resonance frequencies, and bandwidths. For a single square ring antenna, an increase of the size of perforation increases its input impedance, decreases the resonance frequency, and bandwidths. But it affects little on directivity of the antenna. To match the antenna to a transmission line and also enhance its bandwidth, the ring is stacked by a square patch or another square ring. Also numerically simulated results by the IE3D, and experimental data are compared for proof.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.5
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• pp.396-402
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• 2008

This paper presents the structure and performance of a new Integrated magnetics-based transformer, which can be readily adapted to zero-voltage switching full bridge dc-to-dc converters. The proposed transformer features with two paralleled primary windings and a center-tapped secondary winding. The transformer can be fabricated on standard EE or EI cores where the primary and secondary windings are placed on the outer legs while the output filter inductor is wound on the middle leg. The performance of the proposed transformer is demonstrated with a 100 kHz 720 W experimental dc-to-dc converter which recorded a 92% conversion efficiency at 12 V output voltage.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1662-1663
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• 2011

본 논문에서 하지 정맥 지료를 위한 마이크로파 시스템에서 사용될 가열 안테나의 전계 분포를 균일하게 형성시키기 위해 철사 도파관 안테나를 설계 및 제작하였다. 일반적인 도파관 안테나에 경우 안테나 중심 부분에 전계가 가장 세게 분포되어 온도가 다른 곳에 비해 차이가 많이 나므로 인체 피부가 회상을 입힐 위험이 있다. 제안된 철사 도파관 안테나는 끝단에 가느다란 철을 이용하여 전기장을 철사 부분에 집중시켜 안테나 중앙 부분에 집중된 전기장을 분산되도록 설계하였다. 따라서 전기장을 소스로 하는 온도도 균일하게 분포하게 된다. 제안된 철사 도파관 안테나 내부의 전계 분포는 Ansoft 사의 HFSS, 온도 분포는 CST 사의 MWS(Microwave Studio)를 이용하여 시뮬레이션을 하였고, 일반적인 안테나 경우보다 더 균일한 전계와 온도 분포 특성을 보임을 확인하였다. 제작된 철사 안테나는 사용주파수 15GHz에서 -10dB 이하의 반사 손실을 보였다. 또한 안테나 타당성을 검증하기 위해 개구면 앞에 돼지 껍데기를 두고 일정시간 가열하여 일반 안테나와 제안된 철사 도파관 안테나 온도 분포를 비교하였다. 열화상 카메라를 이용한 실험결과 일반 안테나에 경우 중앙과 가장 자리부분 사이에 약 $29^{\circ}C$, 제안된 철사 도파관 안테나에 경우에는 약 $12.5^{\circ}C$의 차이를 보였다. 이를 통해 제안된 철사 도파관 안테나가 전계 분포 균일성 향상에 기여함을 확인하였다.

• The Journal of Korean Physical Therapy
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• v.18 no.1
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• pp.83-94
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• 2006

Purpose: This study conducts quantitative evaluation or structural and functional characteristics or normal skeletal muscle with ultrasound image and surface electromyography, and is to provide basic materials for utilizing ultrasound image analysis in physical therapy diagnosis and assessment of skeletal muscle. Methods: Measurement of three stages was conducted with 88 normal adults between their twenties and seventies, correlations and differences using collected data according to age and gender were compared and correlations among measured items were analyzed and then the following conclusions were obtained. Results: Analysis of ultrasound image of normal skeletal muscle showed that density, median frequency had the closest relations with age. In addition, it was found that there were high correlations between density explaining structural characteristics of skeletal muscle and median frequency explaining functional characteristics. Conclusion: Analysis of ultrasound image makes complex evaluation of structure and function of skeletal muscle possible when it is connected with functional evaluation method using physical measurement surface electromyography as well as quantitative evaluation of structural changes of skeletal muscle and is effective in complementing physical therapy diagnosis centering around functionality evaluation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.4
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• pp.427-435
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• 2008

In this paper, a stable marching-on in time(MOT) method with a time domain combined field integral equation(CFIE) is presented to obtain the transient scattering response from arbitrarily shaped three-dimensional conducting bodies. This formulation is based on a linear combination of the time domain electric field integral equation(EFIE) with the magnetic field integral equation(MFIE). The time derivatives in the EFIE and MFIE are approximated using a central finite difference scheme and other terms are averaged over time. This time domain CFIE approach produces results that are accurate and stable when solving for transient scattering responses from conducting objects. Numerical results with the proposed MOT scheme are presented and compared with those obtained from the conventional method and the inverse discrete Fourier transform(IDFT) of the frequency domain CFIE solution.

• Korea Science and Art Forum
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• v.25
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• pp.379-388
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• 2016

There are some studies to get rid of slice patterns in coronal and sagittal images by FFT(Fast Fourier Transform) and Notch filter. However, the use of a notch filter is the ringing effect according to the rapid frequency change occurs in common. Therefore, this study will be to evaluate the shape and effect of the notch filter. In addition, it is proposed a new notch filter design. Results of the study are as follows. First, Emission-Notch filter was relatively naturally correcting the cutting pattern. Second, Emission-Notch filter to use as Ringing effect is reduced relatively. The next through these findings and further research progress more completely removed the Ringing effect, and expects to reproduce the data close to the actual human body information.

• Journal of the Korean Society of Radiology
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• v.10 no.3
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• pp.215-222
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• 2016

X-ray mammography is the most effective method for the diagnosis of calcified lesions of various breast diseases. To reduce patient dose and to obtain optimal image required for diagnosis, the performance of the mammography system should be maintained continuously. Because the target (anode) angle of the X-ray tube is measured from the central X-ray, the effective angle can be slightly different in view of the position on the detector, which can result in degrading spatial resolution of the imaging within the field of view. In this study, we measured the MTF to examine spatial resolution for positions on the detector in the digital mammography system. For a tungsten wire of $50{\mu}m$ diameter, the highest spatial frequency was obtained. It meant that a wire diameter for measuring MTF through LSF should be small compared to the pixel size of the detector used in the mammography system. The spatial resolution showed slightly different performance according to positions on the detector. The center position gave the best spatial resolution and positions away from the center showed the degraded performance although the difference of the spatial resolution was small. The effective focal spot size of the full width at half maximum also showed similar result. It concluded that the slightly increase of the effective focal spot size gave the degradation of the spatial resolution for positions on the detector.