• Journal of Acupuncture Research
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• 제21권3호
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• pp.83-97
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• 2004

Objective : This study was performed to evaluate the effect acupuncture on cerebral blood flow by Transcranial Doppler Ultrasonography(TCD). Methods : Monitoring of TCD was examined in stroke patients before and after acupuncture on seven points of CVA. Mean Velocity, pulsatility index, systolic velocity, diastolic velocity values are analyzed from TCD at middle cerebral artery. Results : The results showed a insignificant(p>0.05: Paired T-test) decrease in mean velocity, pulsatility index, systolic velocity, diastolic velocity, which was measured at normal middle cerebral artery. The results showed a significant($p{\leq}0.05$: Paired T-test) decrease in mean velocity, pulsatility index, systolic velocity, which was measured at injuried middle cerebral artery, except diastolic velocity. Conclusion : These results suggest that acupuncture could have a specific effect on injuried cerebral artery.

• 한국안전학회지
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• 제27권2호
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• pp.20-24
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• 2012

Experimental studies were performed to investigate the eye injury risks by different BB pellet materials. Four different BB pellet materials were used: plastic (P), silicon (S), rubber (R) and plastic covered with silicon (SR). The BB pellet images penetrating into the gelatine simulant were recorded by a high-speed video camera. The results obtained from the different pellet materials were discussed in terms of impact velocity and penetration depth; threshold velocity and projectile sectional density; eye injury risks by normalized energies. It was found that the P pellets caused higher impact velocity while the lower was SR pellets. The penetration depth and threshold velocity of the pellets were dependent on the impact velocity of the pellets, and the P pellets resulted in the higher eye injury risk while the lower was SP.

• Clinics in Shoulder and Elbow
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• 제27권1호
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• pp.11-17
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• 2024

Background: Rotator cuff tears are often associated with synovitis, but the ability of noninvasive ultrasonography to predict the severity of synovitis remains unclear. We investigated whether ultrasound parameters, namely peak systolic velocity in the anterior humeral circumflex artery and Doppler activity in the glenohumeral joint and subacromial space, reflect synovitis severity. Methods: A total of 54 patients undergoing arthroscopic rotator cuff repair were selected. Doppler ultrasound was used to measure peak systolic velocity in the anterior humeral circumflex artery and Doppler activity in the glenohumeral joint and subacromial space, and these values were compared with the intraoperative synovitis score in univariate and multivariate analyses. Results: Univariate analyses revealed that tear size, peak systolic velocity in the anterior humeral circumflex artery, and Doppler activity in the glenohumeral joint were associated with synovitis in the glenohumeral joint (P=0.02, P<0.001, P=0.02, respectively). In the subacromial space, tear size, peak systolic velocity in the anterior humeral circumflex artery, and Doppler activity in the subacromial space were associated with synovitis severity (P=0.02, P<0.001, P=0.02, respectively). Multivariate analyses indicated that tear size and peak systolic velocity in the anterior humeral circumflex artery were independently associated with synovitis scores in both the glenohumeral joint and the subacromial space (all P<0.05). Conclusions: These findings demonstrate that tear size and peak systolic velocity in the anterior humeral circumflex artery, which can both be measured noninvasively, are useful indicators of synovitis severity.

• 한국지반공학회논문집
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• 제25권11호
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• pp.53-60
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• 2009

터널의 시공은 항상 주변 암반의 손상을 초래한다. 발생하는 손상의 정도는 주변암반의 역학적 및 수리학적 거동에 영향을 미친다. 본 논문에서는 크로스홀 시험을 통하여 P 파 속도를 측정하여 터널주변 암반의 손상을 계측하였다. 발진공에서의 탄성파 신호발생을 위하여 기계적인 충격을 가하였으며 그 결과로 발생된 P파 신호는 잡음이 적으며 파의 초동 도달시간 판별이 용이하였다. 실험결과 암반의 손상이 예상되는 구간에서 P 파의 속도가 낮게 검측 되었다. 크로스홀 공 내 다중의 지점에서 P 파 계측을 수행하여 이차원 P 파 토모그래피를 생성하였는데, 생성된 토모그래피는 터널 배면의 암반 손상이 발생한 구간에 대한 가시적인 결과를 나타내었다. 측정된 P파의 속도로부터 간극율 또는 Q 값과의 상관관계를 통해 암반 특성의 정량적인 손상 평가가 가능하였다.

• 한국콘텐츠학회논문지
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• 제12권9호
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• pp.389-395
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• 2012

본 연구는 전통적인 태권도 정권지르기 기술인 끊어지르기를 어깨를 앞으로 밀어 넣는 밀어지르기와 비교하여 최대 충격력과 주먹의 최고 속도 및 최고속도가 발현된 지점에 대해 규명하였다. 피험자는 남성 태권도 유단자 7명으로 구성하였다. 최대 충격력은 PS2142 force platform[10]을 수직으로 세워 측정하였고, 주먹의 최고속도는 PS2103A motion sensor[12]를 이용하였다. 측정 데이터는 PASCO사에서 제공한 data studio를 통해 수집되었고, SAS 9.1 패키지를 활용해 지르기 방식에 따른 t-test를 실시하였다. 본 실험절차를 통해 나타난 결론은 다음과 같다. 첫째, 최고 충격력에 있어서는 끊어지르기가 밀어지르기 보다 유의한 수준에서(p<.01) 더 높은 것으로 나타났다. 둘째, 주먹의 최고속도는 밀어지르기가 끊어지르기 보다 유의하게(p<.01) 빠른 것으로 제시되었다. 셋째, 최고속도의 발현지점에 있어서는 끊어지르기가 주먹 전체길이의 69.1%, 밀어지르기는 76.6%로 나타났고, 통계적으로 유의한(p<.001) 차이가 있었다.

• 대한통합의학회지
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• 제5권4호
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• pp.77-81
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• 2017

Purpose : This study examined the effects of driving rehabilitation functional training on visual perception ability and driving reaction velocity. Those subjects were put under MVPT-3 test to see their visual perceptual functions before and after the 4weeks' driving rehabilitation function training and then put to TMT A-type test to see their driving reaction velocity performance. The followings are the results of this study. Methods : Using a driving simulator, driving rehabilitation functional training was performed targeting men and women aged in 20s 20 minutes per time, two times per week, for a month. Results : As for the change in visual perception, the Raw Score of MVPT-3 very significantly increased (p<.01), and the Standard Score also very significantly increased (p<.01). As for the change in reaction velocity, TMT A-type very significantly decreased (p<.01), and TMT B-type also very significantly decreased (p<.01). Conclusion : It could be found that driving rehabilitation functional training should be effective for both visual perception and reaction velocity. Consequently, the driving rehabilitation function training can be applied to clinics as training method for functional recovery and improvement of visual perceptual functions and driving reaction velocity performance ability of the patients. Thus, various functional programs should be studied in the future.

• 대한기계학회논문집
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• 제17권6호
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• pp.1423-1430
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• 1993

본 연구에서는 레이저를 사용한 부재의 충돌속도 계측 실험을 통하여 기존 연구자들의 연구 결과를 비교하고, 이 결과를 바탕으로 보다 간단하고 유용한 실험식 을 제안하고자 한다.

• International Journal of Railway
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• 제1권2호
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• pp.64-71
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• 2008

The quality of track-bed fills of railways has been controlled by field measurements of density $({\gamma}_d)$ and the results of plate-load tests. The control measures are compatible with the design procedures whose design parameter is $k_{30}$ for both ordinary-speed railways and high-speed railways. However, one of fatal flaws of the design procedures that there are no simple laboratory measurement procedures for the design parameters ($k_{30}$ or, $E_{v2}$ and $E_{v2}/E_{v1}$) in design stage. A new quality control procedure, in parallel with the advent of the new design procedure, is being proposed. This procedure is based upon P-wave velocity involving consistently the evaluation of design parameters in design stage and the field measurements during construction. The Key concept of the procedure is that the target value for field compaction control is the P-wave velocity determined at OMC using modified compaction test, and direct-arrival method is used for the field measurements during construction. The procedure was verified at a test site and the p-wave velocity turned out to be an excellent control measure. The specifications for the control also include field compaction water content of OMC${\pm}$2% as well as the p-wave velocity.

• 지구물리와물리탐사
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• 제14권4호
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• pp.305-315
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• 2011

암석시료에 대한 음파 속도측정의 정확성을 검증하고 정밀한 측정을 위한 기초적인 실험의 일환으로 아크릴과 스테인리스강 재질의 시료에 대하여 길이와 축하중을 달리하여 각각에 대해 3회씩 측정한 총 864 경우에 대하여, 시험편을 통과한 초동 주시를 측정하고 분석하였다. 축하중이 가해진 상태에서의 S-파 측정은 P-파에 비해 측정에 어려움이 있었으며 이에 따라 반복측정, 길이, 축하중에 의한 편차도 S-파가 훨씬 크게 나타났다. 또한, 재질에 따라서는 스테인레스강 시편보다는 아크릴 시편의 초동주시 편차가 약 2배 정도 양호하게 나타났으며 이는 아크릴 시험편의 경우가 트랜스 듀서와 시험편 간의 접촉 coupling이 안정적이며 또한 동일한 시간 분해능이나 유사한 전기적 잡음에 비하여 초동 주시가 길기 때문으로 판단된다. 실험결과, 아크릴 시험편과 스테인리스강 시험편의 탄성파 속도를 측정할 때는 60 ~ 90 mm 정도의 길이를 갖는 시험편을 20 kg (27.7 $N/cm^2$) ~ 30 kg (41.6 $N/cm^2$) 내외의 축하중 하에서 측정하는 것이 가장 좋으며, 스테인리스강 시험편의 S-파 속도는 길이 50 mm 이하의 시험편을 사용하여 측정해야 한다. 이러한 실험 결과는 암석 코어의 속도 측정시 시스템 지연의 측정 및 보정에 활용될 수 있을 것이다.

• 자원환경지질
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• 제30권6호
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• pp.625-635
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• 1997

A back projection algorithm is applied to 216 Pn travel time measurements to image lateral variations of compressional velocity in the uppermost mantle in the Korean Peninsula. We obtained an average P-velocity value for the uppermost mantle of $7.90{\pm}0.18km/sec$, and an average mantle P-velocity gradient of $5.3{\times}10^{-3}s^{-1}$ for the Korean Peninsula. The final 3-D velocity image in the uppermost mantle is characterized by a low-velocity (about $7.77{\pm}0.12km/sec$) region in the southeast area of the Korean peninsula, which is called 'Kyongsang Basin' and by high-velocity(${\geq}8.08km/sec$) region in the northern area of the Korean Peninsula(Hamkyong and Pyongan provinces). The crustal thicknesses are calculated for the 10 subregions. The crustal thickness of the northern part(${\geq}39^{\circ}N$) of the Korean Peninsula is 33.0-36.0 km, on the contrary, that of the southern part(< $39^{\circ}N$) is 30.7~33.7 km. The velocity image obtained in this study is somewhat consistent with previous S-P travel time studies and gravity studies.