• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.83-83
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• 2017

국내에 유통되는 제초날은 대부분 금속으로 제작되며, 금속 날의 대부분 탄소공구강(SK-3~5)으로 제작되고, 날 수 및 날 형태에 따라 2도 날, 3도 날, 4도 날, 8도 날, 톱날로 구분된다. 대부분 평지 제초작업에 사용되고, 고랑 제초 작업에 알맞은 제초날의 없어 고랑 제초 작업의 효율이 떨어진다. 본 연구는 굴곡이 있는 밭의 고랑 제초 작업에 효율적인 원형 제초날을 설계 하고자 한다. 밭작물의 제초작업은 굴곡이 있는 이랑과 고랑 사이의 잡초를 제거해야 하기 때문에 평지의 잡초를 제거하는 제초날로는 제초작업이 거의 불가능하다. 따라서 고랑 형상에 맞는 원형 제초날을 설계 하였으며, 회전 균형 및 무게의 균일성 설계가 쉬운 뼈대형 원형 제초날을 설계한 후 데이터를 이용하여 원형 제초날을 설계하였다. 또한 고랑의 잡초 뿌리부분을 제거하기 위해 원형 제초날에 돌출부를 추가하는 방법으로 설계하였다. 제초날은 밭작물 고랑폭을 기준으로 하여 높이는 85mm 직경은 300mm로 설계하였으며, 제초날 설계시 원형 제초날은 뼈대형 원형 제초날과 같이 고랑폭을 기준으로 하여 높이 및 직경을 뼈대형 원형 제초날과 동일한 치수로 설계하였다. 원형 제초날 설계에서 돌출부를 볼트 결착방식으로 설계하였으며, 회전중 돌출부의 파손 혹은 이탈을 방지하기 위하여 직경 5mm이상의 볼트 결착이 필요하였다. 볼트 결착방식은 제초날 조립후 제초날 회전시 고랑의 잡초를 효과적으로 제거하기 위한 작업공간 확보가 어려울 것으로 판단되었다. 따라서 제초날 원형부에 돌출부를 절단 절곡하는 방식으로 돌출부를 재설계하였으며, 돌출부 길이는 안쪽 부분 15mm, 바깥 부분 20mm로 설계하고, 돌출부 회전반경은 안쪽 날 20mm, 바깥 날 10mm로 설계하였다. 일반적인 제초날 과 달리 원형 제초날을 개발하기 위해서 회전균형과 안전이 제초날 설계에 중요한 요인이 된다. 뼈대형 제초날을 통하여 제초날의 균형 데이터를 분석하였고 이를 바탕으로 원형 제초날을 설계하였다. 또한 발란싱 머신을 이용한 회전시험에서 unbalance 정도가 3,600rpm에서 4.51/47.1deg로 나타나 제초기에 적용 가능할 것으로 판단되었다.

• 한국노년학
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• v.30 no.3
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• pp.793-802
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• 2010

The purpose of this study was to examine the influence of extreme heat on muscle function and muscle injury marker in elderly women. The subjects of this study were eight post-menopausal elderly women without any metabolic disease. All eight subjects were asked to perform the knee joint isokinetic exercise using isokinetic equipment (cybex) in the laboratory and experimental temperature within laboratory was adjusted to two conditions: extreme heat temperature(33±0.5℃) and normal temperature(20±0.5℃) maintained in 50±3% humidity conditions. Each experimental exercise was monitored and analyzed the change of HSP70, LDH and CK. Muscular functions (peak torque, total work, percentage of peak torque body weight, fatigue index, average power and total work) were significant differences at exercise between temperatural conditions (p<.05). In extreme heat temperature, muscular injury markers (HSP70, LDH and CK) were increased, threfore resulted in significantly higher than normal temperature(p<.05). These results show that extreme heat temperature can decrease muscle function in elderly women.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.3
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• pp.207-214
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• 2016

The aim of this study was to evaluate Influence on intra-limb coordination in individuals wearing knee brace during walking. Seven healthy male adults ($32.3{\pm}2.7$ years old, $175.2{\pm}3.8cm$, $76.2{\pm}8.7kg$) participated. They wore knee brace or didn't wear any knee brace and were asked to walk along a 10 m long walkway. Spatiotemporal parameters, angles of the lower limbs, and intra-limb continuous relative phase (CRP) were measured and calculated. No differences of spatiotemporal parameters were shown (all p > 0.05). There were no changes in the angle and its range of motion (ROM) in the hip for the subjects as wearing knee brace, while ROM ($65.5{\pm}3.7^{\circ}$ vs. $60.5{\pm}3.5^{\circ}$, p < 0.05) of the angle and maximum flexion angles (stance: $31.9{\pm}4.6$ vs. $25.6{\pm}5.5$, swing: $76.7{\pm}3.1$ vs. $68.9{\pm}3.4$, all p < 0.05) in the knee significantly decreased. No changes in ROM of angle in the ankle were shown, whereas maximum dorsiflexion decreased ($22.4{\pm}2.6$ vs. $19.2{\pm}2.1$, p < 0.05) and maximum plantarflexion increased ($9.5{\pm}3.0$ vs. $15.7{\pm}2.2$, p<0.05). There were no changes in most of CRP between joints. CRP between the hip and knee joints decreased ($93.0{\pm}7.8$ vs, $84.7{\pm}4.9$, p < 0.05). Most of CRP standard deviation increased (between the hip and ankle joint during swing: $25.1{\pm}6.7$ vs. $32.4{\pm}1.9$, between the knee and ankle joint during stance: $46.0{\pm}12.9$ vs. $80.1{\pm}31.1$, between the knee and ankle joint during swing: $34.5{\pm}4.1$ vs. $37.6{\pm}3.1$, all p < 0.05). These results indicated that wearing knee brace affected joint angle and intra-limb coordination, but less affected gait features.

• Journal of the Korean Arthroscopy Society
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• v.8 no.2
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• pp.82-88
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• 2004

Purpose: In this study, we intended to ascertain the benefit of KT-2000 Knee arthrometer(KT-2000) in the diagnosis of ACL(Anterior cruciate ligament) injury by comparing the anterior displacement of normal knee with that of ACL deficient knee. Materials and Methods: We designated two examiners to measure the anterior displacement of the knee joint of 30 healthy individuals, using KT-2000, at 30$^{\circ}$ flexion setting of muscle full relaxation, contraction, 25$^{\circ}$ internal rotation and 25$^{\circ}$ external rotation and analyzed these results according to the variables and measured the preoperative anterior displacement of the ACL injured knee in the 30 patients who have gone through an arthroscopic ACL reconstruction later. Results: The results of examiner 1 are 6.5${\pm}$1.5 mm, 2.5${\pm}$0.9 mm, 4.8${\pm}$1.2 mm, 6.4${\pm}$1.3 mm in right knee and 5.6${\pm}$1.3 mm, 2.1${\pm}$0.8 mm, 4.5${\pm}$1.2 mm, 5.2${\pm}$1.3 mm in left knee, in order of muscle full relaxation, contraction, 25$^{\circ}$ internal rotation and 25$^{\circ}$ external rotation. The results of examiner 2 are 6.9${\pm}$1.2mm, 2.9${\pm}$1.1mm, 5.6${\pm}$1.6mm, 6.9${\pm}$1.5mm in right, 5.5${\pm}$1.7 mm,1.9${\pm}$0.9 mm, 5.1${\pm}$1.9 mm, 5.7${\pm}$1.6 mm in left knee, The side to side difference of examiner 1 in the setting of muscle relaxation is 0.9${\pm}$1.0 mm. The anterior displaement of ACL injured knee is average 11${\pm}$2.93 mm and difference of average 6.5${\pm}$2.31 mm form that of normal. In comparison between the right and left knees of healthy individuals, the both results of two examiners showed the statistical difference in the setting of muscle full relaxation but, the results showed the side to side difference below 2 mm in 25case(83%), 21case(70%) respectively and above 3 mm in just 1 case. In the comparison between the normal and ACL injured knees, the results show the statistical difference of the side to side difference in the setting of muscle relaxation(p<0.05). Conclusion: The KT-2000 result is affected by relaxation of muscles around knee, flexion angle of knee joint, rotation of tibia, the strength of displacing force, time of the test and physical factors as height and weight. However, the Accuracy of diagnosis of ACL injury by KT-2000 will increase if the examiner is skillful and the tests are made on the exact position of knee joint.

• Investigative Magnetic Resonance Imaging
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• v.14 no.1
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• pp.47-55
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• 2010

Purpose : To evaluate the geometry of carotid artery by assessing the images of contrast-enhanced MR angiography (CE-MRA) and interrelationships between the geometry of carotid artery and clinical factors. Materials and Methods : 216 consecutive patients who performed supraaortic CE-MRA with fast spoiled gradient-echo imaging were included. Their medical records were reviewed for variable information including risk factors predictive of generalized atherosclerotic disease (age, hypertension (HTN), diabetes mellitus, hyperlipidema, and smoking), sex, body weight, height, and body mass index (BMI). We reviewed the CE-MRA with carotid origin (3 types), carotid artery tortuosity, angle of internal carotid artery bifurcation, the type of aortic arch branching, and the presence of the coiling of carotid artery. Results : Multinomial logistic regression analysis showed that significantly contributed clinical backgrounds for carotid origin were the age and the BMI. With an increase of age at 1, the probability that the type of carotid origin become from type 1 to type 2 was 0.9 times (p=0.004) in right carotid artery (RCA), 0.9 times (p = 0.031) in left carotid artery (LCA), 0.9 times that are likely to be type3 from type 2 (p<0.001) in RCA and 0.9 times in LCA (p=0.009). Increase in BMI at 1 increased odds of becoming type 2 as 1.1 times (p = 0.067) in RCA, 1.1 times (p=0.009) in LCA and increased chance of becoming type 3 as 1.2 times (p = 0.001) in RCA, 1.2 times (p=0.003) in LCA. Mean value of right and left carotid tortuosity were $240.9{\pm}69.0^{\circ}$and $154.4{\pm}55.0^{\circ}$, respectively. Conclusion : The BMI, age, sex and presence of HTN affects the geometry of carotid arteries, the site of origin and tortuosity of carotid artery specifically.

• Journal of the Korean Arthroscopy Society
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• v.8 no.1
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• pp.14-18
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• 2004

Purpose: To compare the mid-term follow-up results of anterior cruciate ligament(ACL) reconstruction with the bone-patellar tendon- bone(BTB) autograft to those with the BTB allograft. Materials and Methods: Retrospective study was performed in 59 cases with BTB autograft and 42 cases with BTB allograft. Evaluations include Lysholm score, 2000 IKDC subjective knee score, Shelbourne patello-femoral pain score , Lachman test, pivot shift test, KT-1000 arthrometer test and 2000 IKDC knee examination. Results: There were no significant statistic differences between two groups in Lysholm score and 2000 IKDC subjective knee score of more than 70 (p<0.05). Five cases(8.5%) showed the patello-femoral pain score less than 80 according to Shelboume with autograft group and two cases(4.8%) with allograft group (p<0.05). Lachman test, pivot shift test and KT-1000 arthrometer test showed no significant statistic differences between two groups(P<0.05). Fifty-four cases(91.5%) were normal or nearly normal according to the 2000 IKDC knee examination with autograft group and thirty-eight cases(90.4%) with allograft group(p<0.05).Conclusion: BTB allograft as well as BTB autograft is considered to be an acceptable choice for ACL reconstruction.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.137-146
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• 2008

The purpose of this study is to examine the causes of errors from EGR posture on the balance beam, which is bending flick-flack salto backward stretched national team players through kinematic analysis, and present training methods for them so as to provide scientifically useful information to coaches and athlete. Findings from this study are summarized below. The most important factors that affect the errors in boyd center position and speed change were the speed change of left and right body centers and the horizontal and vertical speed changes. The left and right acceleration changes were greater in failed posture than in successful posture. The horizontal and vertical accelerations in E3 and E5 were the key factors that affected the backward somersault and landing. The angular speed changes which varied between success and failure were notable in head and shoulder joints. In individual results. The section when the angular speeds of head and shoulder joint must be the greatest was E4. In this section, when the body is extending instantly in a bent posture, increasing the angular speeds of head, shoulder and hip joints can improve the duration of staying in the air and the rotation radius of a somersault.

• Science of Emotion and Sensibility
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• v.13 no.3
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• pp.467-474
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• 2010

Recently, Study of functional clothing for Vital sensing is focused on reducing artifact by human motions, in order to enhance the electrocardiogram(ECG) sensing accuracy. In this study, considering the factors for each element found from the analysis, a 3-lead electrode inside textile embroidered with silver yarn was developed, and draft designs off our types of vital-signal sensing garments, which are 'chest-belt typed' garment, 'cross-typed' garment 'x-typed' garment and 'curved x-typed' garment, were prepared. The draft designs were implemented on a sleeveless male shirt made of an elastic material so that the garment and the electrodes can remain closely attached along the contour of the human body, and the acquired data was sent to the main computer over a wireless network. In order to evaluate the effects caused by body movements and the ECG-sensing capability for each type in static and dynamic states, displacements were measured from one and two dimensional perspectives. ECG measurement evaluation was also performed for Signal-to-noise ratio(SNR) analysis. Applying the experimental results, the draft garment designs were modified and complemented to produce two types of modular approaches 'continuous-attached' and 'insertion-detached' for the ECG-sensing smart clothing.

• Water for future
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• v.14 no.1
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• pp.39-49
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• 1981

The purpose of this study is to examine the meander charactericstics for the rivers in Korea..In this study, the new characteristics factors of meander are proposed, and the relationships among the factors proposed in this study and the existing factors are derived. An attempt is made to find considerable relation among meander characteristics, but width and meander belt did not show any defined trend and considerable scatter of points was observed. Relationships among the meander length, belt and flowrate, etc., which are factors of meander characteristics, are analyzed the 67 rivers above 30km in length. Channel shape factor which is the ratio of the length from the starting point to the end to the channel lenght, tortuosity which is the ratio of the curved channel length against the channel length are suggested for a new characteristics factor of meander. They are well correlated with channel length, Horton's shape facotr and meander gradient, consequently have to be important measures of river meander. The result of the detailed comparison and the analysis of degree of sinuosity, velocity and water surface slop are brought light on the fact show that the curved reach is morestable than the straight one. The ratio of the meander length to the meander belt and its accumulative frequency showed excellent correlationship when plotted on the semi-log paper. The results of regression analysis of meander belt and meander length show linear for the South Han river branches and power curve for the Geum river and the Nakdong river branches.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.4
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• pp.25-34
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• 2010

This study was conducted to develop evaluation indicators to improve athletic performance and operational management of golf courses and the results of the research are as follows. Through theoretical research and a preliminary professional survey, 15 on-going evaluations of golf course composition and operational management and 55 sub-evaluation indices were rejected while 10 on-going evaluations and 52 sub-evaluation indicators were reconfigured as final for environmental-friendliness, level of member services, level of human service of game personnel, difficulties of course, management level of the course, fairness of operational management, accessibility and location characteristic, traditions and ambiance of the golf club, quality of course, and course layout. When analyzing the important decision factors in golf course user preference evaluation indicators, the following contributed in the order of higher to lower contributions: the management level of the course, excellence of the course, level of human services for personnel, course layout and environmental-friendliness. When identifying the path coefficient of golf course evaluation indicators, the curvature of a hole and the length of the course had a causal effect on the 'course layout' section. Tournament facilities and various shot values had a causal relationship with 'excellence of the course', in the order of higher to lower, and convenience of waiting and fair allocation of reservations for 'fairness of operational management'. The history of the golf course and its environmental characteristics, history and culture of the region have relatively higher causal effects on 'traditions of the golf club' and geographical conditions on 'accessibility and location characteristics', pesticide and fertilizer usage and water pollution on 'environmental-friendliness', and member benefit and kindness of employees on 'level of member services'. The kindness and expertise of the game personnel had a relatively higher causal effect on the 'level of human services of game personnel', the location of tenning area, and location of OB and hazards on 'difficulties of course', and rough conditions and obstacles management on 'management level of the course'. There is a need to complete a systematic evaluation index system for golf course user preferences through future studies for a more detailed assessment, as well as a process to verify these evaluation indicators by application to domestic and international golf courses.