• Journal of Radiation Protection and Research
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• v.26 no.3
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• pp.333-335
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• 2001

The 2 GeV electron linac, the injector of the Pohang Light Source, was used as a photo-neutron source for radiation shielding research. The operational beam parameters are the nominal electron intensity of $0.5\;{\sim}5\;nC/sec$, the repetition rate of 10 Hz, and the beam pulse length of 1.0 nsec. One electron beam line was modified in order to install the target systems for producing pulsed photo-neutrons. The neutron spectrum and intensity were investigated by the time-of-flight technique. The reliable maximum energy of the measured neutrons was about 500 MeV. The number of neutrons above 20 MeV produced by one 1 GeV electron in a thick Pb target was about $6.45{\times}10^{-4}/sr$ at 90 degrees to the beam axis. The status of the photo-neutron source and the application research are presented.

• The Journal of Korean Physical Therapy
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• v.11 no.1
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• pp.149-156
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• 1999

Resistive therapeutic exercise prescription goal is to improve functional performance and capabilities through the development of increased muscular strengh endurance or power. Resistance can be applied to either dynamic or static muscle contractions. Resistive therapeutic exorcise can be carried nut concentrically, eccentrically, isometrically, isokinetically. Neurodevelopmental treatment has not resistive therapeutic exercise concept. But proprioceptive neuromuscular facilitate techniques have resistive therapeutic exercise concept with pattens and techniques. It is aid muscle contraction, motor control and increase strength. Manual muscle testing will help the therapist establish a qualitative and quantitative baseline level of strength. Manual resistance maybe applied a against controlled lengthening contraction re static contraction of a muscle. A repetition maximum is not easy to calculate and is not the most accurate method available today to measure strength before of after a resistive therapeutic exercise program. Oddvar Holten Diagram is essy to calculate and is the most accurate method available today to measure strength before of after a resistive therapeutic exercise program. Plyometric training emphasize the development of muscular power and coordination. Quick bursts of force in functional movement patterns are often necessary of a patient is to return to high-demand occupational, recreational or sports related activities.

• Korean Journal of Applied Biomechanics
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• v.28 no.3
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• pp.151-158
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• 2018

Objective: In this study, we analyzed kinematic changes in the start phase of speed skating before and after physical training. Method: We introduced a new strength training program (2017) that was improved in terms of exercise type and intensity [%, one repetition maximum (1RM)] compared with the previous strength training program (2016). The new program was applied to elite speed skating athletes (four males and four females). To determine the improvement in starting technique, we recorded race images during the start phase of the 500-m race held in 2016 and 2017. The race images were collected using five high-speed cameras and kinematic characteristics of the start phase were analyzed by three-dimensional image analysis. Results: The 1RMs were improved by 11% on an average after the strength training. In 2017, records of four out of the eight athletes were shortened in terms of the initial lap time (100 m), and 500-m records were shortened in six athletes. The time to nine strokes was shortened in five athletes, and the ratio of correct kinetic chain was increased or maintained at a high level in six athletes. Conclusion: In this study, the new strength training program (2017), applied to elite speed skating athletes, showed a positive effect on starting technique and reduced the record times.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.5
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• pp.871-876
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• 2006

In this thesis, to accurately measure 3D face information using the spatial encoding patterns, the new algorithm to segment the pattern images from initial face pattern image is proposed. If the obtained images is non-homogeneous texture and ambiguous boundary pattern, the pattern segmentation is very difficult. Furthermore. the non-encoded areas by accumulated error are occurred. In this thesis, the FCM(fuzzy c-means) clustering method is proposed to enhance the robust encoding and segmentation rate under non-homogeneous texture and ambiguous boundary pattern. The initial parameters for experiment such as clustering class number, maximum repetition number, and error tolerance are set with 2, 100, 0.0001 respectively. The proposed pattern segmentation method increased 8-20% segmentation rate with conventional binary segmentation methods.

• Speech Sciences
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• v.15 no.4
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• pp.159-170
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• 2008

The purpose of this study was to find out the ability of coordination of the articulatory motor and the ability of control of the respiration and laryngeal for spastic dysarthria by acoustic analysis. The sustained of vowel /a/ and repetition of syllable /pa/ in 15 normal and 10 spastic dysarthria were measured. Multi-Speech, MDVP, and MSP were used for data recording and analysis. As a result, the mean DDK rate in the spastic group was significantly slower than in the normal. The maximum phonation time in the spastic group ($4.80{\pm}1.94$) was shorter than in the normal ($11.20{\pm}3.72$). The DDKjit in the spastic group was significantly higher than in the normal. The DDKsla was reduced in the spastic group. The mean syllable duration in the spastic group (146.2ms) was significantly longer than in the normal (75.8ms). The mean energy was reduced in the spastic group. The range of Fo was greater than in the normal. The frequency perturbation (jitter, vFo) and amplitude perturbation (shimmer, vAm) were higher than in the normal group. The NHR was higher than in the normal group. The parameters of this were significantly difference between the spastic dysarthria and the normal (p<0.05). Finally, the spastic dysarthria has short respiration, slow speech rate, and voice quality problem. The these results will help to establish a plan and the intervention of treatment.

• Journal of Biomedical Engineering Research
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• v.20 no.3
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• pp.275-281
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• 1999

Conventional PW Doppler systems suffer from the ambiguity of measured blood velocities due to the spectrum aliasing when the corresponding Doppler frequencies are greater than the Nyquist frequency. Base-line shift is a customary method for dealiasing the Doppler spectrums. I lowever, Doppler audio signals still remain unchanged even when the base-line shift method is applied. This paper de scribes an method for dealiasing both the Doppler spectra and audio signals by using sampling rate expansion, frequency shifting, and filtering poerations. For undirectional flows, the method can increase the maximum detectable Doppler frequency from the Nyquist limit of one-half of the Pulse Repetition Frequency(PRF) to the PRF. Experiments with real data have been performed to verify the proposed method.

• Journal of the Korean Solar Energy Society
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• v.27 no.1
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• pp.39-45
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• 2007

In this paper, we analyzed the elements of measurement uncertainty on electrical performance test which are the most important things in photovoltaic module performance test. Repeating the performance test by 6 men, the measurement uncertainty could be calculated. In this experiment, Solar Simulator (A-Class pulse type) used for domestic certificate test of PV module is Pasan IIIb (Balval, Switzerland). The possible elements of the measurement uncertain that could effect electrical performance test of PV module are reference cell, spectrum correction, error from measurement repetition, test condition, stability and uniformity of artificial solar simulator. To find the measurement uncertainty, 6 men repeated the test by 10 times. And the results were that numerical average value was 124.44W and measurement uncertainty was $124.44W{\pm}0.36W$ with 95% confidence level for 125W PV module(KD-5125).

• Current Optics and Photonics
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• v.1 no.5
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• pp.525-528
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• 2017

High-energy, high-power, quasi-continuous wave (QCW) operation of double-clad Yb fiber lasers incorporating an incoherent signal combiner is reported. We constructed four efficient, high-power Yb fiber lasers, each of which produced rectangular pulses at 1080 nm with a pulse energy greater than 15 J, and a pulse duration of 10 ms at a repetition rate of 10 Hz, corresponding to an average power of over 150 W and a peak power of over 1.5 kW for ~200 W of incident pump power at 915 nm. These laser outputs were combined by a homemade incoherent fiber signal combiner with low loss, yielding a maximum peak power of ~6.0 kW in a beam with $M^2{\approx}12.5$. The detailed laser characteristics and prospects for further power scaling in QCW operation are discussed.

• Physical Therapy Rehabilitation Science
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• v.2 no.1
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• pp.7-11
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• 2013

Objective: Final goal of nerve advancement therapy is to provide maximum ability to function independently in life to patients. This paper appraises and describes basic concepts of the virtual reality (VR) based exercise program to improve functional movement for neurologically impaired patients. Design: Review article. Methods: Stroke patients from the physical therapy department while wearing comfortable clothing receive therapy and also VR based motion therapy administered by the therapist in charge. After evaluation of stroke patients, therapy includes an exercise program that is suitable for use with stroke patients; stroke patients wear head-mounted display while in front of the computer, where the camera is located; they follow the action on the screen and the computer perceives the operation of the stroke patients according to subject accomplishment. Results: According to obstacle condition of stroke patients using the method, which is various environments after setting, in stroke patients, there is a possibility of presenting suitable therapeutic environments. The display presentation of the method, which is identical, causes difficulty for all stroke patients. According to subject accomplishment; stroke patients result in execution of repetition training and deepening study, which leads to mobility. Conclusions: The VR based rehabilitation training programs is a difference of the existing video training program, is immediate feedback and compensation method. It will provide rehabilitation training services for the family of the patient whose condition could be improved with rehabilitative therapy where it is a continuous circumstance as a matter of the social welfare facility therapy.

• Journal of Electrical Engineering and Technology
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• v.7 no.6
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• pp.971-976
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• 2012

A 150 kJ compact capacitive pulsed power system (CCPPS) capable of delivering electrical energy into an electrothermal chemical (ETC) gun on a vehicle has been studied. The CCPPS provides pulsed electrical energy into a capillary plasma injector which generates plasma of tens of thousands $^{\circ}K$ in temperature and has a nonlinear resistance depending on the current. The design requirements of the CCPPS are as follows: the maximum power of 250 MW, the pulse width of about 0.6 ms, the volume of no more than 0.5 cubic meter, the efficiency of energy transfer over 80 % and the repetition rate of 4~5 times per minute. The constructed CCPPS is composed of four 37.5 kJ capacitor bank modules in parallel to make a trapezoid pulse shape and to satisfy the design requirements. Each module is designed to achieve high reliability, safety, efficiency and energy density to endure severe operating conditions. The results of the performance test on the CCPPS using a 120 mm ETC gun are described.