• 수산해양기술연구
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• 제48권1호
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• pp.1-9
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• 2012

For the optimal design of a shrimp pot to control the catch size and to reduce catch the small size shrimp, tank experiments were carried out to study the pot stability under water. Tank experiments were carried out to measure the drag with 4 kinds of model pots that have 50% selection on the individual of 25mm carapace length. The drag of each pot was measured every 10 times with changing the current speeds from 0.1m/s to 0.7m/s in 0.1m/s intervals and the pot attack angle from $0^{\circ}$ to $90^{\circ}$ in $15^{\circ}$ interval in a flume tank. The relation between the current speed and drag was presented. The stability of pot was estimated using the drag data and the friction data of Kim et al. (2008b). The results showed that, the drag was shown lower as small as the projected area of pot depending on the current speeds and angles. The model pots were showed to slide on the seabed in case of rock at the current speeds 0.35-0.38m/s and the possibility of turn over at the current speeds 0.77-0.89m/s. In conclusion, the stability of a shrimp pot showed more stable as the pot of the lower the height and the smaller projected area on current.

• Journal of Trauma and Injury
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• 제28권4호
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• pp.248-255
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• 2015

Purpose: study of the mutual influence of the individual anatomical regions damage in patients associated with falls from heights. Methods: 561 medical reports of patients associated with falls from heights admitted to Republican Research Center of Emergency Medicine (RRCEM), in period of 2010-2013 yy, were analyzed retrospectively. Patient's age range was from 15 to 89. Treatment of these patients held in three stages: period of acute disorders of vital functions; relative stabilization period; stabilization of vital functions. The scope and content of medical diagnostic procedures performed on pre-hospital and intensive care stages. The severity of each injury was scored according to the AIS scale, the total severity of lesions was scored by points due to ISS. Digital material is treated by methods of mathematical statistics. Results: Falls from heights leads to associated injuries for 4 times more than isolated trauma, and increases according to height of fall and falling surface. Patients with TBI+chest trauma, are most serious contingent that has highest mortality and complications (36.8%). TBI+musculoskeletal system trauma are characterized by high blood loss, traumatic shock and fat embolism, forming a vicious circle. Conclusion: in patients associated with falls from heights clinical manifestations of injuries mutual aggravation syndrome will be seen. TBI leads to complication of chest trauma, delayed diagnostics of abdominal and chest trauma, aggravation of coma condition. Developing of high blood loss and fat embolism in musculoskeletal system trauma leads to shock and pulmonary embolism, which increases probability of death in the presence of abdominal or chest trauma, but abdominal trauma or chest trauma has no significant effect on the severity of the musculoskeletal system trauma.

• Journal of Korean Neurosurgical Society
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• 제50권3호
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• pp.224-230
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• 2011

Objective : This study aimed to show the possibility of neural canal enlargement and restoration of bony fragments through laminectomy and minimal facetectomy without pediculectomy or an anterior approach, and also to prove the adequacy of posterior stabilization of vertebral deformities after thoracolumbar bursting fracture. Methods : From January 2003 to June 2009, we experienced 45 patients with thoracolumbar burst fractures. All patients enrolled were presented with either a neural canal compromise of more than 40% with a Benzel-Larson Grade of VI, or more than 30% compromise with less than a Benzel-Larson Grade of V. Most important characteristic of our surgical procedure was repositioning retropulsed bone fragments using custom-designed instruments via laminectomy and minimal facetectomy without removing the fractured bone fragments. Beneath the dural sac, these custom-designed instruments could push the retropulsed bone fragments within the neural canal after the decompression and bone fragment repositioning. Results : The mean kyphotic deformities measured preoperatively and at follow-up within 12 months were 17.7 degrees (${\pm}6.4$ degrees) and 9.6 degrees (${\pm}5.2$ degrees), respectively. The mean midsagittal diameter improved from 8.8 mm (${\pm}2.8$ mm) before surgery to 14.2 mm (${\pm}1.6$ mm) at follow-up. The mean traumatic vertebral body height before surgery was 41.3% (${\pm}12.6%$). At follow-up assessment within 12 months, this score showed a statistically significant increase to 68.3% (${\pm}12.8%$). Neurological improvement occurred in all patients. Conclusion : Though controversy exists in the treatment of severe thoracolumbar burst fracture, we achieved effective radiological and clinical results in the cases of burst fractures causing severe canal compromise and spinal deformity by using this novel custom-designed instruments, via posterior approach alone.

• 한국전자통신학회논문지
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• 제12권4호
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• pp.591-598
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• 2017

현재 무인항공기의 기술 변화와 시장 규모는 발 빠르게 확산되고 있다. 활용 범위의 확대로 드론을 쉽게 접할 수 있게 되면서 조종자의 조종 미숙으로 인한 피해가 발생한다. 이러한 문제 발생으로 인한 피해를 최소화하기 위해서 드론의 안정적인 비행 능력이 요구되며 이를 위하여 모터의 안정적인 속도 제어가 요구된다. 따라서 본 논문에서는 모터의 제어 방안으로 Arduino를 주 제어장치로 사용하였으며 기체의 자세 안정화를 위하여 가속도 센서와 자이로 센서를 사용하였다. 또한, 초음파 센서를 드론에 탑재하여 일정 높이에서 호버링이 가능하도록 하였다. 안드로이드 앱을 이용하여 드론을 제어하였으며 그 결과 0~2m 범위의 지정한 위치에서 안정적으로 호버링이 가능함을 확인하였다.

• 한국전문물리치료학회지
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• 제10권1호
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• pp.63-76
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• 2003

This research was performed to compare spinal segment motion angle between low back pain (LBP) group and painless group during trunk flexion-extension and to investigate the effect of transversus abdominis strengthening exercise on spinal segment motion angle in LBP group. Nine subjects with LBP and ten subjects without LBP participated. Transversus abdominis strengthening exercise was performed in LBP group for three weeks, and spinal segment motion angles were compared before and after the exercise performance. Spinal segment motion angles were measured both in sitting and standing position. Results were as followed: 1) Subjects' average age was 24.79 years, height was 167.84 cm, and weight was 59.95 kg. 2) Spinal segment motion angle of T10/l1 was significantly higher in LBP group compared with painless group (p<.05) in sitting position during trunk flexion-extension. 3) In sitting position, whereas entire lumbar segment motion angles were lower in LBP group compared with painless group (p<.05), angle of L4/5 was higher in LBP group compared with painless group (p<.05). 4) There was no significant difference in thoracic segment motion angle in standing position. 5) After three weeks of transversus abdominis strengthening exercise, thoracic segment motion angle increased both in sitting and standing position (p<.05). 6) In painless group, there was no significant difference in entire spinal segment motion angles in sitting and standing position (p>.05). When spinal segment motion angles were compared between sitting and standing position, there were slight differences. In sitting position, there was no difference in spinal segment motion angle between LBP group and painless group while hip joint motion angle and sacral inclination angle of LBP group was lower than those of painless group (p<.05). In standing position, lumbar segment motion angle was significantly lower in LBP group than that of painless group. Transversus abdominis strengthening exercise influenced thoracic segment motion angle more significantly than lumbar segment motion angle.

• 한국전문물리치료학회지
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• 제20권3호
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• pp.81-88
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• 2013

Active straight-leg raise (ASLR) is a physical evaluation procedure to test lumbar spine stability. Several previous studies have reported various methods to control the activation of abdominal muscles during ASLR. We investigated the effects of three different hip positions in frontal plane on abdominal muscles to increase or decrease the difficulty level of lumbar spine stability exercise during ASLR in pain free subjects. Eleven young and healthy subjects voluntarily participated in this study (6 men, 5 women; mean age=$24.0{\pm}1.2$ years, height=$160.0{\pm}7.3cm$, weight=$55.0{\pm}10.6kg$, body mass index=$21.5{\pm}2.3kg/m^2$). The subjects had three trials on each ASLR with hip $10^{\circ}$ adduction, neutral hip, and hip $30^{\circ}$ abduction. Separate repeated-measures analysis of variance (ANOVA) and the post hoc Bonferroni tests (with ${\alpha}$=.05/3=.017) were performed for each muscle among the three different hip positions in frontal plane (ASLR with hip $10^{\circ}$ adduction, neutral hip, and hip $30^{\circ}$ abduction). The ipsilateral external oblique (EO), contralateral EO, ipsilateral internal oblique/transverse abdominis (IO/TrA), and contralateral IO/TrA were significantly greater in ASLR with hip $30^{\circ}$ abduction compared with ASLR with hip $10^{\circ}$ adduction. Also, the ipsilateral EO, contralateral EO, and ipsilateral IO/TrA were significantly greater in ASLR with hip $30^{\circ}$ abduction compared with ASLR with neutral hip. These results suggest that ASLR with hip $30^{\circ}$ abduction and neutral would be useful method to strengthen the EO and IO/TrA. And, ASLR with hip $10^{\circ}$ adduction would be effective in early stages of lumbar stabilization program due to low activation of EO and IO/TrA during maintaining of ASLR position with low load.

• Environmental Engineering Research
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• 제19권3호
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• pp.261-268
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• 2014

Leachate quality and methane emission from pilot-scale lysimeters operated under semi-aerobic and anaerobic conditions were monitored for 650 days. Two semi-aerobic lysimeters were filled with un-compacted and compacted municipal solid wastes whereas two anaerobic lysimeters containing compacted wastes were operated with leachate storage at 50% and 100% of waste height, respectively. Despite having high moisture in wastes and operating under tropical rainfall events, leachate stabilization in semi-aerobic lysimeters took place much faster resulting in BOD reduction by 90% within 60 days, significantly shorter than 180-210 days observed in anaerobic lysimeters. Nitrogen concentration in leachate from semi-aerobic lysimeter could be reduced by 90%. In term of gas emission, semi-aerobic lysimeter with un-compacted wastes had much lower methane emission rate of $2.8g/m^2/day$ compare to anaerobic lysimeters ($62.6g/m^2/day$) through seasonal fluctuation was observed. Nevertheless, semi-aerobic lysimeter with waste compaction has similar performance to anaerobic lysimeter.

• 한국전문물리치료학회지
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• 제29권1호
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• pp.79-86
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• 2022

Background: Bird dog exercise (BDE) is one of the lumbar stabilization exercises that rehabilitate low back pain by co-contraction of the local and global muscles. Previous studies have reported the effect of various type of BDEs (for example, practicing the exercises on various surfaces and changing the limb movement) for muscle co-contraction. Objects: This study aimed to investigate the effect of knee joint flexion position of the raised lower limb on abdominal and back muscle activity during BDE in patients with chronic low back pain (CLBP). Methods: Thirteen males participated in this study (age: 32.54 ± 4.48 years, height: 177.38 ± 7.17 cm). Surface electromyographic (SEMG) data of the internal abdominal oblique (IO), external abdominal oblique (EO), lumbar multifidus (MF), and thoracic part of the iliocostalis lumborum (ICLT) were collected in two knee joint flexion positions (90° flexion versus 0° flexion) during BDE. The SEMG data were expressed as a percentage of root mean square mean values obtained in the maximal voluntary isometric contraction. Results: Greater muscle activity of the IO (p = 0.001), MF (p = 0.009), and ICLT (p = 0.021) of the raised lower limb side and the EO (p = 0.001) and MF (p = 0.009) of the contralateral side were demonstrated in the knee joint flexion position compared to the knee joint extension position. Greater local/global activity ratios of the abdominal muscle (i.e., IO and EO) of the raised lower limb (p = 0.002) and the back muscle (i.e., MF and ICLT) of the contralateral side (p = 0.028) were also noted in the knee joint flexion position. Conclusion: BDE with a knee joint flexion position might be recommended as an alternative lumbar stabilization exercise to enhance muscle activity in both the raised lower limb and the contralateral sides of the trunk for individuals with CLBP.

• 한국지반공학회논문집
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• 제26권7호
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• pp.59-70
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• 2010

대상지역 내 중금속 오염농경지 복원을 위해 설계된 안정화 공법에 대한 현장 적용성을 검토하기 위해 현장실증시험을 수행하였다. 대상오염 농경지에 처리구들을 설치하여 오염토양만을 채운 무처리구를 제외한 각 처리구에 중금속 안정화 재료로 선정된 석회석과 산업부산물인 제강슬래그를 각각의 혼합비로 채운 후, 관측기간동안 처리구 내 토양을 채취하여 이화학특성, 중금속농도(Cu, Cd, Pb, Zn, As) 그리고 중금속 분획특성 등을 분석하여 그 특성을 비교하였으며, 그 결과를 수록하였다.

• 한국환경농학회지
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• 제37권2호
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• pp.87-96
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• 2018

BACKGROUND: The vigorous shoot growth in upper part of apple tree canopy leads to poor fruit quality and flower bud formation in lower part of canopy. So, this study was conducted to develop the proper control method about the shoot growth in upper part of apple tree canopy. METHODS AND RESULTS: Trunks of 'Fuji'/M9 apple trees were cut (back pruned) to 2.5 m in tree height on 11 February (dormant) or 12 April (full bloom). Naphthalene acetic acid (NAA) was applied at 2.0% to cut surface when trunk was pruned. Prohexadione-calcium (Pro-Ca) was sprayed at 250 mg/L above 2.0 m in tree height at 23 April (petal fall). The NAA or Pro-Ca application after trunk was pruned at dormant (TR-2 and TR-3) significantly reduced shoot growth in upper part of canopy compared with the control (tree was only pruned at dormant, TR-1), but the percent of shoots showing the secondary growth of TR-3 was higher over 2 times than that of TR-2. The reduction of shoot growth in upper part of canopy by TR-2 and TR-3 increased the fruit red color from the lower part in the treating year and blooming of the lower part in the following year. CONCLUSION: Applying 2.0% NAA to cut surface of pruned apple trunk at dormant was the most effective way for stabilization of the tree vigor in upper part of the canopy in a high density apple orchard.