평판형 die 내를 흐르는 단섬유 현탁계의 섬유배향과 압출팽창에 관한 수치해석

이종훈,박용민,이기준 ( Chong Hoon Lee,Yong Min Park,Ki Jun Lee ) 한국화학공학회 1993 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.31 No.4

The effects of the geometrical shape of extrusion dies and the fiber orientation at the entrance on fiber orientation and die swell were analyzed numerically by finite element method. The fiber orientation and the interaction among the fibers were analyzed by way of the orientation tensors. The fibers near the die wall aligned along the flow direction regardless of its initial orientation. But the fibers near the center line retained its initial orientation. It was verified that the use of extrusion dies of contraction or expansion entrance made it possible to control the fiber orientation significantly. The C_I value which represents the interaction among fibers also affects the orientation and the die swell. The orientation disturbed and the swell ratio increased as the C_I increases. The swell ratio decreased in expansion die but increased in contraction die as the L/D ratio increases. The swell ratio when fibers were introduced as aligned state was smaller than the case of randomly introduced state.

스탈린주의의 근대성과 ‘밤의 마녀들’

이종훈(Lee, Chong-hoon) 한국외국어대학교 역사문화연구소 2010 역사문화연구 Vol.37 No.-

소비에트 권력은 나치독일과의 총력전을 경험하면서 여성들을 최전선의 적진폭격을 위한 야간비행에 내세우기까지 하였다. 그러나 이것은 권력에 의한 강제라기보다는, 1930년대 소비에트 여성들에게 주입된 근대성, 예를 들어 양성평등, 여성의 공적영역 진출, 건설ㆍ개척과 자연정복, 꿈과 미래의 영역인 창공, 과학기술의 총아인 비행기 조종과 낙하산 점프, 유사시 사회주의 조국수호의 성스러운 임무 강조 등의 결과로 인한 여성들의 ‘자발적’ 참여라는 측면이 매우 강하다. 본질적으로는 여성동원이면서도 상당수 여성의 적극적인 ‘동의’가 표출되었다는 점에서, 대중독재의 한 유형인 스탈린체제의 성격이 극명하게 드러나는 대목이기도 하다. 아울러 여성의 적극적 참여와 동의라는 형태로 대중적 동원과 조직화에 일정하게 성공했다는 점에서 권력에 내장된 근대성이 두드러지게 나타나는 경우이기도 하다. 필자는 당시 몇몇 여성 비행사나 항법사의 기록에서 제시되고 재생산되는 당시 소비에트 사회의 지배담론에 유의하면서, 이를 여성 전투원이 내면화하고 전유한 모습을 밝히면서 스탈린체제의 근대화 프로젝트가 전시 여성의 의식과 행동 속에 여전히 영향을 주고 있음을 제시하고자 한다. Over the course of the Great Patriotic War, 1941-1945, Soviet women volunteered to the front. Among them were ‘the Night-Witches’, some decades of women who also mastered night bombers, in particular. Women’s compatibility with combat, in defense of their country was a product of the radical changes that Stalinist society underwent in the 1930s.

카약 스프린트 종목에서 패들 그립너비가 카약 전방 스트로크 동작과 보트 안정성에 미치는 영향

이종훈(Lee, Chong-Hoon),남기정(Nam, Ki-Jung),박용현(Park, Yong-Hyun) 한국체육과학회 2013 한국체육과학회지 Vol.22 No.3

The purpose of this study was to identify the contribution that paddle grip width has to successful performance during the forward stroke movement pattern, and boat stability in kayak sprinting. Eight male elite kayak athletes participated in this study. Kayak athletes performed kayak sprinting with three grip width conditions (preferred grip(PGW); narrow grip(NG); wide grip(WG)) while stroke frequency, paddling distance, knee joint ROM and angular velocity, trunk rotation ROM, boat stability, integrated EMG(rectus femoris: RF, biceps femoris:BF) were measured and analyzed. The results showed that kayak performance with preferred grip width condition is better than others. For the wide grip width, rotation of trunk is larger and iEMG of Biceps femoris. However, the boat stability was affected negatively. There were no overall significant differences, but some conditions were significant differences in Bonferroni’s post hoc test. Wide grip width helps make more rotation of trunk and more iEMG value of BF, but no good performance because of large ROM of boat roll angle. Large ROM of boat roll can be was a main factor reducing kayak velocity. The improvement of paddling technique to minimize ROM of rolling angle is needed for kayak athletes to use a wide grip width.

카약 스트로크 동작의 고찰

이종훈(Lee, Chong-Hoon),남기정(Nam, Ki-Jeong) 한국체육과학회 2013 한국체육과학회지 Vol.22 No.4

Successful kayak stroke requires a powerful and skilful paddler with an appropriately designed kayak and blade to effectively maximize power to provide forward propulsion and minimize negative drag forces. With a greater understanding of the biomechanical properties and design characteristics of kayaking, coaches and athletes can work towards successful paddling performances. Examination of what is occurring biomechanically under the stress of competition is an important step in improving race times. Since the introduction of kayaking as a sport, an increase in the understanding and research behind the biomechanics of flatwater kayaking has, in part, contributed to improved race times. This information may aid coaches in the development of more specific training programmes for their athletes. It is the purpose of this paper to review previous literature regarding the biomechanical principles of flatwater kayaking and certain design modifications in the context of its application to improving paddling performance.

백스쿼트와 프런트스쿼트의 동작 차이 비교

이종훈(Lee, Chong-Hoon),남기정(Nam, Ki-Jeong),김재필(Kim, Jae-Pil) 한국체육과학회 2013 한국체육과학회지 Vol.22 No.6

The purpose of this study was to investigate the change in motion and the load distribution between the front and back squat. With these purposes in consideration, 7 experienced weight lifters peformed both front and back squat. In order to analyze the change in motion and the load distribution of the two types of squat the following variables, ankle joint angle, knee joint angle, body angle, foot pressure, muscle activity using the 3D motion system, foot pressure system and EMG wireless system were compared. Here are the following results. Firtst, for the front squat ankle joint angle at event 2 was smaller but knee joint angle was between the two types of squat there was no significant difference. Second, foot pressure for all phases was no significant difference. Third, all of the phases the Upper muscle EMG values were higher while preforming the front squat. All things considered, the change in motion and the load distribution are different depending on the squat type. It is concluded that the front squat is effective exercise for developing overall muscles and the back squat is go여 for developing the quadriceps strengthening and the stability of upper body.

알파인과 프리스타일 스노보드 라이딩자세의 운동학적 분석

이종훈(Lee, Chong-Hoon),남기정(Nam, Ki-Jeong),전윤걸(Jeon, Youn-Girl) 한국체육과학회 2016 한국체육과학회지 Vol.25 No.2

The purpose of this study was to analyse kinematic variable of alpine and freestyle snowboards" riding posture. A total of 6 elite male snowboard athletes(n=6; alpine:4, freestyle:2) were recruited to participate. The experiment was performed on a slope for intermediate(red-course) while the COG (Pelvis) acceleration data and lowlimb joint angles were recorded by IMU sensor(Noraxon, USA) and analysed. The participants were ridden through 12 gate poles with 12m gap. Results show that: In BSturn, the ROM of Righthip-flexion between alpine(37.78±15.08) and freeystyle(95.58±5.73) snowboards were significant difference(p<.05). In Fsturn, the ROM of Leftthip-flexion between alpine(38.67 ±6.63) and freeystyle(60.99±6.92) snowboards were significant difference(p<.05). The Leftthip-rotation"s ROM between alpine(75.15±7.59) and freeystyle(29.80±2.19) snowboards were significant difference (p<.05). Distinction between alpinesnowboard and freestyle snowboard posture is occurred by seeing ahead position in alpinesnowboard(like a ski). We need biomechanical understanding of characteristic between alpine and freestyle snowboards for top performance.

전신 및 상체 하네스를 활용한 스노보드 지상훈련자세의 운동역학적 비교 분석

이종훈(Lee, Chong-Hoon),백진호(Back, Jin-Ho),남기정(Nam, Ki-Jeong),엄길호(Eom, Kil-Ho),전윤걸(Jeon, Youn-Girl) 한국체육과학회 2018 한국체육과학회지 Vol.27 No.4

We consider the biomechanical analysis of four professional male snowboarders in order to produce basic data, which allows for improving the snowboarding performances of both athlete and amateur snowboarders. We measured the low limb angle and main muscle activation on snowboarding while the male snowboarder was in a snowboard riding and accoutered with whole body harness or upper body harness in simulator. The results show that the use of the whole body harness is more effective in restricting on hip joint and in activatiing left lateral gastrocnemius when the male snowboarder maintained snowboarding posture on the simulator. Our study suggests that application of whole body harness will be more suitable to posture training on the simulator than using upper body harness.

골프 드라이버 샷 동작의 족저압 분석

이종훈(Lee, Chong-Hoon) 한국체육과학회 2018 한국체육과학회지 Vol.27 No.5

The purpose of this study was to examine the biomechanical factors during the golf driver swing in major phases and to provide insight into the efficient swing movements for golf professionals. Four male collegiate golfers performed swings with a driver while foot pressure was measured. At address, the subjects’ weights were distributed evenly between feet or slightly more on the right foot. During the backswing, their weights progressively moved into the right foot until the top of the backswing. During the downswing, the weights started moving back to the left foot. After the impact and finish, all the weights moved to the left foot. During a driver swing, the center of pressure movements in right to left and front to back directions were not consistent among subjects but all the movements indicated facilitation of weight transfer and usage of the ground reaction force.

스노보드 지상 훈련법의 효과 검증

이종훈(Lee, Chong-Hoon),남기정(Nam, Ki-Jeong),전윤걸(Jun, Yoon-Gul),최진성(Choi, Jin-Sung) 한국체육과학회 2014 한국체육과학회지 Vol.23 No.4

The purpose of this study was to analyse motion of the one-turn in alpine snowboard. A total of 4 elite Alpine snowboard players were recruited to participate. The experiment was performed slope for experts while the kinematic three dimensional data was recorded and analyzed. Results show that: The height of the center of the mass at the fall line is 83.67±5.41 ㎝, the change of the center of the mass is 0.54±0.48 ㎝, the maximum speed in the center of mass is 25.14±3.82 ㎧, the angle of line of the COM at the fall line is 38.7±4.19 degree, the ROM of trunk angle is 15.72±4.66 degree, the ROM of upper-left thigh angle is 8.49±3.84 degree, the ROM of steering angle is 3.73±2.48 degree, the distance from flag is 1.24±O.55 m.

밀리터리 프레스 시 상완과 몸통의 각도에 따른 삼각근의 근활성도 비교

이종훈(Lee, Chong-Hoon),임성준(Lim, Seong-Joon),정재홍(Jeong, Jae-Hong),남기정(Nam, Ki-Jeong) 한국체육과학회 2018 한국체육과학회지 Vol.27 No.6

The purpose of this study was to analysis of electromyogram of Pectoralis Major and Triceps Brachii during Push-Up Exercise. With these purposes in consideration, a total of 9 male were recruited to participate. The experiment was performed push-up exercise during one minute(with 5 min break-time) while the EMG data was recorded and analyzed. EMG surface electrodes were attached two muscles(Pectoralis Majoj; PM and Triceps Brachii; TB). Results show that there were significant differences between PM and TB during push-up exercise at 120% shoulder width. It is concluded that the push-up exercise at 120% shoulder width is only effective exercise for developing PM.