• 제목/요약/키워드: Kick-back

검색결과 23건 처리시간 0.025초

고종횡비 비대칭 구조물의 발파붕괴 거동에 관한 연구 (An Experimental Study on Blasting Collapse Behavior of Asymmetry Structure with High Aspect Ratio)

  • 송영석;정민수;정동월;허원호
    • 화약ㆍ발파
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    • 제31권1호
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    • pp.1-10
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    • 2013
  • 발파해체 공법은 구조물 형상과 주변현황에 따라 다양한 공법을 적용할 수 있으나, 고종횡비를 가지는 비대칭 구조물을 발파해체 하기 위해서는 사전취약화와 발파지점 및 시차와 주변현황에 따른 발파조건을 고려하여 설계하여야 한다. 본 연구에서는 고종횡비 비대칭 구조물을 안전하게 전도시키기 위해 ELS 소프트웨어를 사용하여 사전취약화 위치와 형상에 따른 모멘트 발생지점을 분석하여 킥백(kick back)을 제어할 수 있는 사전취약화 위치 및 형상에 대한 시뮬레이션을 수행하였으며, 비대칭 구조물의 붕괴 시 전도방향의 좌우로 발생하는 비틀림 모멘트(torsional moment)를 최소화하기 위해 붕괴방향을 제어 할 수 있는 발파 시차 및 위치를 선정하였다. 또한 시뮬레이션상의 사전 취약 및 발파시차를 실 구조물의 전도 붕괴에 적용하여 붕괴 거동에 대한 모션분석을 하였다. 그 결과 시뮬레이션의 붕괴거동에 대한 신뢰성을 확인하였으며, 발파해체 시 사전취약화의 형상 및 위치에 따라 킥백을 제어할 수 있으며, 발파 위치와 시차에 따라 비틀림 모멘트를 제어 할 수 있다는 것을 알 수 있었다.

고속 CMOS A/D 변환기를 위한 기준전압 흔들림 감쇄 회로 (A DC Reference Fluctuation Reduction Circuit for High-Speed CMOS A/D Converter)

  • 박상규;황상훈;송민규
    • 대한전자공학회논문지SD
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    • 제43권6호
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    • pp.53-61
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    • 2006
  • 고속 Flash, Pipelining type의 CMOS A/D 변환기에서 Sampling frequency가 고주파로 올라감에 따라 Clock Feed-through 현상, Kick-back 현상 등의 영향으로 DC Reference voltage 흔들림 현상이 심화되고 있다. 뿐만 아니라 측정 시 외부 Noise가 Reference voltage에 적지 않은 영향을 미친다는 것을 감안 할 때 High speed A/D converter에서 Reference fluctuation 감쇄회로는 반드시 필요하다. 기존의 방식은 단순히 커패시터를 이용했으나 면적이 크고 효과가 좋지 않다는 단점이 있다. 본 논문에서는 Transmission Gate를 이용한 reference fluctuation 감쇄 회로를 제안하고 흔들림 현상이 크게 개선되었음을 정량적 분석 및 측정을 통하여 증명하였다. 제안하는 회로의 측정을 위해 6bit의 해상도를 갖는 2GSPS CMOS A/D 변환기를 설계 및 제작하였다. 제작된 A/D 변환기를 이용하여 Reference 전압이 40mV의 흔들림이 있음에도 원하는 범위 내에서 동작함을 측정하였다. 본 연구에서는 1.8V $0.18{\mu}m$ 1-poly 5-metal N-well CMOS 공정을 사용하였고, 소비전력은 145mW로 Full Flash 변환기에 비해 낮았다. 실제 제작된 칩의 SNDR은 약 36.25dB로 측정되었고, INL과 DNL은 각각 ${\pm}0.5$ LSB 이하로 나타났다. 유효칩 면적은 $997um\times1040um$ 이었다.

축구선수의 킥 동작시 키네시오 테이핑 적용에 따른 하지근활성화 및 동작분석 (Analysis of Low-leg Activation and Movement of Soccer Players during Kicking Action by Applying Kinesiotaping)

  • 김용재;모안나
    • 한국운동역학회지
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    • 제17권2호
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    • pp.131-143
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    • 2007
  • In this study, we are concluded like this : 5 men who are soccer player of P university in B city measure the Electromyography with an angle of motion according to kinesiotaping's application when practicing in-step kick. When exercising in-step kick, the change of realization of muscle load of lower limbs enhence Gastrocnemius Lateralis and Vastus Medialis in the section of backswing, and improve Tibialis Anterior, Vastus Medialis, Rectus Femoris prior to impact after back-swing. Before impact, it mainly impoved Tibialis Anterior, Vastus Medialis, Rectus Femoris. After impact, it generally improved Gastrocnemius Lateralis, Vastus Medialis. Average integral electromyography value, it was such a small difference(; the difference of the value in Tibialis Anterior, Rectus Femoris, Vastus Medialis) that we can't compare case of after taping than before. In Electromyography, in case of after taping was considerably decreased at Gastrocnemius Lateralis, there was statistically significant difference between before and after. It was a little increased, after taping than before at Knee angle. And degree was a little decreased at Ankle angle. But, It's so delicate difference, there was not statistically significant difference between before and after.

우세한 다리와 비우세한 다리 사이의 태권도 발차기 비교 (Unilateral Performance Comparison for Taekwondo Kicks between Dominant Leg and Non-Dominant Leg)

  • 김영관;김윤혁
    • 한국운동역학회지
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    • 제20권2호
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    • pp.183-189
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    • 2010
  • The balanced performance of dominant and non-dominant leg is very important to Taekwondo sparring. The purpose of this study was to investigate whether elite Taekwondo athletes would have balanced biomechanical performance and intra-limb coordination in executing different types of Taekwondo kicks. Twelve athletes(more than 10 year practice experience) participated in this study and performed six basic kicks(i.e., the front, roundhouse, side, back, thrashing, and turning-back kick). Results indicated no statistical difference on response time, peak kicking velocity, single limb vertical jump height, and angle-angle plot between dominant leg and non-dominant leg(p>.05). In conclusion, elite Taekwondo athletes had equivalent ability between dominant leg and non-dominant leg in performing Taekwondo kicks. This might be an advantage to elite athletes for Taekwondo sparring because they could use both leg without any restriction.

태권도 경기 중 스포츠 손상에 대한 분석 (Analysis of the Sports Injury in the Taekwondo Matches)

  • 허진강;김광수
    • 대한정형도수물리치료학회지
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    • 제5권1호
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    • pp.75-80
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    • 1999
  • The Taekwondo being a martial sports, there are higher chances for the injury to occur than the non martial sports. Therefore, this study analyze the frequency, the area, the type, and the condition of the injury which are prone to occur in the Taekwondo matches; it is to help the Taekwondo players in prevention of the injury and in treatment. The subjects of this study were the 48 players (male 24, female 24) who participated in the final selection contest of the national team player on March 9 to 12, 1993. The data of the injury were obtained from the medical recoder staff and were analyzed to the frequency of the injury per match, the vulnerable area of the injury, the type of injury, and the condition of the injury with a gender difference. There were 24 matches for the male and 24 matches for the female, total 48 matches. Therefore, the total participation number of the players are the double of the match number. 1. The frequency of the injury per match was 18.3%(11/60) for male and 23.1%(12/52) for women. 2. The areas of the injury were ankle 36.4%(4), foot 18.2%(2), knee 18.2%(2), lower leg 18.2%(2), wrist 9.1%(1) in male; foot 33.4%(4), ankle 16.7%(2), knee 16.7%(2), lower back 16.7%(2), lower leg 8.3%(1), face 8.3%(1) in female. 3. The types of the injury were contusion 45.5%(5), sprain 27.3%(3), abrasion 9.1%(1), laceration 9.1%(1), tendon rupture 9.1%(1) in male; contusion 33.3%(4), sprain 33.3%(4), abrasion 16.7%(2), subcutaneous hemorrhage 8.3%(1), dislocation 8.3%(1) in female. 4. The condition of the injury were the unblocked attack 36.4%(4), attacking kick 27.3%(3), blocking a kick 18.2%(2), attacking punch 9.1%, impact with surface 9.1%(1) in male; attacking kick 33.3%(4), unblocked attack 25%(3), blocking a kick 25%(3), attacking punch 8.3%(1), impact with surface 8.3%(1) in female. This study shows that the injury from the Taekwondo matches occurred most in the lower extremity joints and the foot, and shows that the most of the injury types were contusion and sprain. Therefore, it is believed to be helpful to wear the proper fitting ankle or the knee protector and using other protective equipment to prevent the sports injury in the Taekwondo matches.

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태권도 뒤후려차기 동작시 숙련자와 비숙련자의 근전도 비교 (The Comparison of Expert with Non-Expert EMG during Perform Back-round Kicking of Taekwondo)

  • 김재우
    • 한국실천공학교육학회논문지
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    • 제3권1호
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    • pp.200-205
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    • 2011
  • 본 연구의 목적은 첫째 뒤후려차기시 이용되는 주요 근육들의 근전도 반응을 분석하고, 둘째 지지하는 다리와 차는 다리의 근육들 사이의 관계를 분석하고, 셋째 숙련자와 비숙련자간 EMG 값의 차이를 분석하는 것이다. 측정된 근육들은 다음과 같다: 슬관절과 대퇴골, 내측광근과 외측광근을 굴곡과 신전을 조절하고, 대퇴골의 신전, 슬관절의 굴곡, 그리고 정강이의 외전을 조절하는 대퇴직근. 선택된 모든 근육의 근전도 반응이 분석되었다. 3개의 발차기가 수행되었고, 각 발차기의 근전도가 분석되었다. 그때 최상의 발차기의 근전도 반응이 근전도 분석에 이용되었다.

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링 운동 차오르며 Swallow 동작 처치 전.후의 기술분석 (Longitudinal Kinematical Analysis of Kip to Swallow Motion in Rings)

  • 백진호;박종훈;이용식
    • 한국운동역학회지
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    • 제16권3호
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    • pp.173-181
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    • 2006
  • The purpose of this study is grasp the problem of the gymnast, Kim, Dong-Hwa's Kip to Swallow Motion in Rings, and make up for the weak points to help him to perform a better performance. Therefore, two tryouts for $28^{th}$ Athens Olympic Games were filmed using video camera then finalized with Kinematical Analysis using 3D motion analysis program followings are the form of conclusions. 1. In the very first tryout, when he was doing a Swallow Support Scale, his CM position was high and arm slope was deduction because when he was doing Kip, the ascent velocity was low and he tried excessively to pull him on rings due to relying upon angular movement of shoulder joint. 2. When he was doing drop, he let his hip angle bend only little bit and let fall so making shoulder angle wider and maintain the level horizontally occurs strong drop motion when vertical descent is happening. 3. As a result, lowering the direction of a kick makes CM's movement path lower, increase vertical ascent velocity, and it helps to do the Swallow Support motion in short period of time. 4. After a strong drop motion, which is deep and fast, would make rope of ring shake so there is a defect that the body moves to forward area. However, it does not effect in Swallow Support Scale motion. 5. In the second tryout, trunk rotation angle and arm slope was fixed decrease while doing rotary motion. When rotary motion was happening, before the body was going under the rings, maintained his arm slope horizontally so his Swallow Support Scale motion was nearly perfect.

카오스 발진을 위한 RL-광결합기 회로 연구 (A Study on a RL-Photocoupler Circuit for Chaos Oscillation)

  • 정동호;정설희
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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    • pp.2835-2838
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    • 2003
  • We study the characteristics of oscillating in non-autonomous condition and the conducted noise generation in a RL-photocoupler circuit. This circuit may be shown a period-doubling and a chaos dynamics under any specific conditions of input circuit. But, the relationship between input signals and output signals is different according to the amplitude of driving input voltage. Then, the oscillation noise was analyzed with respect to both the frequency and the amplitude of an external ac signal and do values. The results show that the noise-induced oscillations for falling and rising cycles induced by kick-back effect in an inductor, nonlinear capacitance, nonlinear resistance and charge storage time in a diode and an LED. We also compared the simulation with the experimental results.

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Lumbar Disc Herniation in Tae Kwon Do Athletic Child

  • Kim, Sung-Hoon;Kim, Hyeun-Sung;Kim, Seok-Won
    • Journal of Korean Neurosurgical Society
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    • 제48권6호
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    • pp.538-540
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    • 2010
  • Lumbar disc herniation is extremely uncommon in children below 10 years of age. A 7-year-old boy is reported who presented with low back pain and left leg radiating pain. The pain started seven days prior to presentation and was attributed to performing the jumping kick without any previous warm-up. Magnetic resonance imaging revealed a posterolateral disc herniation at the L3-4 level and multiple degenerative changes. The patient received conservative treatment including limitation of sports activities, anti-inflammatory and muscle relaxant medications as well as physical therapy. After three months of the aggressive treatment the child was symptom free. We present here a lumbar disc herniation in one of the youngest patient.

A 0.25-$\mu\textrm{m}$ CMOS 1.6Gbps/pin 4-Level Transceiver Using Stub Series Terminated Logic Interface for High Bandwidth

  • Kim, Jin-Hyun;Kim, Woo-Seop;Kim, Suki
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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    • pp.165-168
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    • 2002
  • As the demand for higher data-rate chip-to-chip communication such as memory-to-controller, processor-to-processor increases, low cost high-speed serial links\ulcorner become more attractive. This paper describes a 0.25-fm CMOS 1.6Gbps/pin 4-level transceiver using Stub Series Terminated Logic for high Bandwidth. For multi-gigabit/second application, the data rate is limited by Inter-Symbol Interference (ISI) caused by channel low pass effects, process-limited on-chip clock frequency, and serial link distance. The proposed transceiver uses multi-level signaling (4-level Pulse Amplitude Modulation) using push-pull type, double data rate and flash sampling. To reduce Process-Voltage-Temperature Variation and ISI including data dependency skew, the proposed high-speed calibration circuits with voltage swing controller, data linearity controller and slew rate controller maintains desirable output waveform and makes less sensitive output. In order to detect successfully the transmitted 1.6Gbps/pin 4-level data, the receiver is designed as simultaneous type with a kick - back noise-isolated reference voltage line structure and a 3-stage Gate-Isolated sense amplifier. The transceiver, which was fabricated using a 0.25 fm CMOS process, performs data rate of 1.6 ~ 2.0 Gbps/pin with a 400MHB internal clock, Stub Series Terminated Logic ever in 2.25 ~ 2.75V supply voltage. and occupied 500 * 6001m of area.

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