• 소음진동
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• 제10권2호
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• pp.247-253
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• 2000

The evaluation of the ride quality had been performed by the subjective method before ISO2631(International Organization for Stadard 2631) and BS6841(British Standard 6841) was precented, but many research programs have been performed by the objective method after that. On this study, the ride quality was evaluated related with the objective method which considered the vibration which the human body feels on the driver's seat while driving on the road. In particular, we made the shock absorber nonlinear model and also selected the suitable shock absorber in the part of the vibration which the human body feels into the simulation. The shock absorber of suspension was dealt with 3 cases respectively with the front wheel and rear wheel. The vibration of the car driving on the road can be transferred to the wheel, the suspension, the vehicle body, the seat and the human body. The signal which was gained from the seat(hip) and the floor(foot) of the human body was changed to the vibration signal which the human body felt through using the frequency weighting function. And then the performance of the shock absorber was calculated through the statistic processing.

• 동의신경정신과학회지
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• 제12권2호
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• pp.53-68
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• 2001

This study was performed to investigate the anti-depression effect of Guibiondamtang in rat model of depression. The rats in the experiment were stratified into 3 groups, ie, Guibiondamtang, saline, normal (non-stressed) groups. Chronic exposure to mild unpredictable stress such as white noise, flashing lights and restriction of food and water, causes the behavioral symptoms correspondent to depression. Consumption of 1% sucrose solution fell in rats exposed to CMS for 4 weeks. In the open field test , the exploratory activity ie. locomotion and centering decreased after CMS. We then evaluated the sucrose consumption and activity during 4 weeks of treatment with experimental drugs. The results were as follows: 1) There was no relation between sucrose intake and weight. 2) The Guibiondamtang(歸脾溫膽湯) group reinstated sucrose consumption within 5-6 weeks while having no influence on sucrose intake in normal group. 3) The Guibiondamtang(歸脾溫膽湯) group restored some exploratory activity in the open field test. 4) The Guibiondamtang-group had a-reduced potentiated startle response.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2013년도 하계학술대회
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• pp.274-277
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• 2013

CT(Computed Tomography)영상에서 선량과 화질은 중요한 요소이다. 선량은 환자에게 직접적으로 악영향을 끼치는 요소이며, 화질은 환자의 병변을 판단하는데 매우 중요하게 작용한다. 반복적 재구성 알고리즘을 이용하면 저선량 영상에서도 고화질의 영상을 얻을 수 있는지 FBP와 정량적, 정성적으로 비교하였다. 촬영 프로토콜은 관전압 80, 100, 120kVp에서 관전류를 동일하게 200mA로 촬영하여 획득하였으며, 정량적 평가를 위해 SD(Standard Deviation), SNR(Signal to Noise Ratio), MTF(Modulation Transfer Function)를 측정하여 분석하였다. 선량은 80kVp일 때 가장 낮았으며, 120kVp일 때 가장 높았다. 80kVp의 영상을 Toshiba 사(社)의 AIDR 3D(Adaptive Iterative Reduction integrated into $^{SURE}Exposure$)로 재구성하고, 120kVp의 영상에 FBP로 재구성한 다음 정량적 비교를 한 결과 AIDR 3D를 적용한 영상의 SD가 낮게 나왔으며, SNR이 높게 나타났고, MTF 곡선은 유사하게 나타났다. 그리고 FWHM(Full Width at Half Maximum) 값의 오차가 거의 없었다. 결론적으로 AIDR 3D는 저선량에서도 높은 화질을 나타냄을 확인하였다.

• 대한인간공학회지
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• 제15권2호
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• pp.25-36
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• 1996

The purposes of the present study were: (1) to investigate aeromedical dissorders prevalent among ROK air force pilots and (2) to evaluate their detrimental effects on flight performance. The study examined the eight flight-induced disorders primarily responsible for permanent grounding and flying restrictions. According to the survey of 600 randomly selected pilots, 80.2% of the respondents have experienced low back pain, which was 20% higher than the lifetime prevalence in Swedish male workers. Bradyacusia ranked second (56.0%) resulting from continuous exposure to high aircraft noise. The cardiovascular disorders, the most common cause for permanent grounding of Canadian forces pilots, were found in 16.0% of the Korean pilots. Due to the high prevalence of the disorders, in 1993 the Korean pilots received medical treatments 10 times as many as factory workdes. Compared to the flight performance of Israeli and British pilots in wars, the flight performance of the Korean pilots was found to be inferior. Such poor performance can be attributable to the high incidence rates of disorders. Statistical analyses revealed that the aeromedical disorders were related to personal variables such as age, flight career- related factors, and fatigue. Cigarette smoking and drinking habit contributed to worsening back pain, barotitis media, and pulmonary disorders. More comprehensive research was recommended to identify health hazards, combined with intervention to minimize disorders that could lead to early termination of flight careers or excessive loss of flight time. This study further suggests that aeromedical institutions in Korean air force should be fostered more professionally and financially.

• 한국전자파학회논문지
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• 제14권9호
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• pp.936-943
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• 2003

초소형 무선내시경은 CMOS Image sensor, FPGA, LED, Battery,DC to DC Converter, Antenna 그리고 송신기로 구성되어 있다. 최대 전자파 노출규제, 시스템의기, 전력소모, 선형성 및 변조방법 등을 고려하여 지름 10 mm, 두께 2.3 mm인 FSK송신기를 설계, 제작 및 측정하였다. 제작된 송신기는 1.2 GHz 대역에서 동작하며, -3.67dBm의 출력전력, -99dBc/Hz(@100 KHz offset)의 위상잡음, -20.17 dBc의 고조파 억압을 나타내었다. 동물실험에서 제작된 무선내시경용 FSK 송신기는 만족할만한 성능을 나타내었다.

• 천문학회보
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• 제35권1호
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• pp.92-92
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• 2010

A short-period comet, 17P/Holmes, is one of the most outstanding comets because of the outburs in 2007. It orbits the sun at the distance between 2.1AU and 5.2 AU with the orbital period of 6.9 year. On 2007 October 23, its brightness was suddenly increased by about a million times from 17 mag to 2.5 mag. We made observations of 17P/Holmes soon after the outburst on October 25, 27 and 28, using a 105cm telescope at the Ishigakijima Astronomical observatory, Japan. We took the images with V, R and I-band filters simultaneously. Total exposure times are 15 (October 25), 69 (October 27), and 37 (October 28) minute in each filter. The composite images provide good signal to noise ratio and help us to recognize faint structures embedded in the dust cloud. We examined a sequence of images using a digital filter that enhances the small-scale structures. As the result of the data analysis, we confirm (1) the radial expanded structure coming out from the nucleus of comet, and (2) dozens of blobs that moved radially away from the nucleus. In this presentation, we introduce the observations and the data reductions, and consider the origins of these fine structure.

• 방송공학회논문지
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• 제16권2호
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• pp.247-257
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• 2011

본 논문에서는 장면의 밝기에 적합한 셔터 속도를 가진 두 장의 LDR (low dynamic range) 영상을 취득하여 HDR (high dynamic range) 영상을 고속으로 생성하는 효율적인 기법을 제안한다. 즉, 장면의 밝기에 최적인 HDR 영상을 취득하기 위해 본 논문에서는 오직 두 장의 초기 입력 LDR 영상을 이용하여 장면의 밝기에 대한 노출 곡선을 초기 추정한 후, 장면의 밝기 변화에 따른 최적의 셔터 속도를 시간 변화에 따라 지속적으로 추정하는 기법을 제안한다. 성능 평가를 위해 기존의 고화질 HDR 기법으로 생성한 영상과 제안된 방법으로 취득된 영상간의 유사도를 PSNR (peak signal to noise ratio)로 비교하였으며, 모든 두 장의 조합을 탐색하지 않고도 최적에 근사하는 두 개의 셔터 속도를 얻을 수 있음을 보인다.

• Journal of Astronomy and Space Sciences
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• 제14권2호
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• pp.251-258
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• 1997

The detection of jovian hydrogen-hydrogen dimers through the clear telluric 2-micron window(Kim et al. 1995, Trafton et al. 1997( suggests possibility to detect noble gases in the form of dimer with hydrogen in jovian atmospheres. Since noble noble gases do not have spectral structures in the infrared, it has been difficult to derive their abundances in the atmospheres of jovian planets. If there is a significant component of noble gases other than helium in the jovian atmospheres. it might be detected through its dimer spectrum with hydrogen molecule. The relatively sharp spectral structures of hydrogen-argon and hydrogen-neon dimers compared with those of hydrogen-hydrogen dimers are useful for the detection, if an adequate signal-to-noise (S/N) is obtained. If we use a large telescope, such as the Keck telescope, with a long exposure time (>24 hours), then $H_2-Ar$ spectral structure may be detected.

• 한국재료학회지
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• 제16권7호
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• pp.455-459
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• 2006

Coincidence Doppler Broadening (CDB) of positron annihilation spectroscopy was applied to analyze defects in the chemical state of Department of Physics, $Gd_2O_2S$:Tb intensifying screens. The screen samples were irradiated by 80 MV X-rays in hospital and were used for 0, 2, 4, and 6 years respectively. There was a positive relationship between the S-parameter values and time of exposure to X-rays. Most of the defects were indicated to have been generated by X-rays. A 1D CDB was developed in order to reduce the background noise, and the S-parameter values of the $Gd_2O_2S$:Tb intensifying screens, using the 1D CDB, varied between 0.4974 and 0.4991.

• 천문학회보
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• 제37권2호
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• pp.91-91
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• 2012

We present high-resolution near-infrared host galaxy spectra of low-z quasars, PG0844+349 (z=0.064), PG1226+023 (z=0.158), and PG1426+015 (z=0.086). The observation was done by using the near-IR high resolution echelle spectrometer, IRCS, at the SUBARU 8.2 m telescope. The full width at half maximum of the point spread function was about 0.3 arcsec by using an Adaptive Optics system, which can effectively resolve the quasar spectra from the host galaxy spectra. The signal-to-noise ratios are increased by the total exposure time up to several hours per targets and the development of data reduction method. We compare our results to the stellar spectra library and sample spectra from Dasyra et al. (2007) and Watson et al. (2008). The identified spectral lines will be used to study the physical mechanism of quasars, and the velocity dispersions of the stars in the bulge of the host galaxy.