• 제목/요약/키워드: Long endurance

검색결과 201건 처리시간 0.025초

유소년의 골연령에 따른 체력 표준지표 개발 (Development of Physical Fitness Standard Indicators According to the Bone Age in Youth)

  • 김대훈;윤형기;오세이;이영준;조석연;송대식;서동녘;김주원;나규민;김민준;오경아
    • 한국응용과학기술학회지
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    • 제38권6호
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    • pp.1627-1642
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    • 2021
  • 본 연구는 유소년의 골연령에 따른 체력을 평가하는 데 있으며, 골연령에 따른 체력 표준지표를 통해 유소년들의 균형적인 발달을 위한 기초자료를 제공하는 데 있다. 연구 대상은 골연령 11세~13세 및 역연령 11세~13세에 해당하는 730명을 대상으로 하였으며 골연령 산출을 위해 X-ray 필름을 촬영한 후 TW3 방법으로 평가하였다. 체격은 신장, 체중을 신장계(Hanebio, Korea, 2021), Inbody 270(Biospace, Korea, 2019)를 사용하여 총 2개의 체격 요소를 측정하였으며, 체력은 근력(악력), 평형성(외발서기), 민첩성(플랫테핑), 순발력(제자리멀리뛰기), 유연성(좌전굴), 근지구력(윗몸일으키기), 심폐지구력(셔틀런)으로 총 7개 체력 요소의 종목을 측정하였다. 자료처리 방법은 SPSS PC/Program(Version 26.0)을 이용하여 기술통계, 독립표본 t-test 검정을 실시하였으며, p< .05수준에서 유의한 것으로 간주하였다. 본 연구의 결과는 다음과 같다. 첫째, 11세~13세 골연령과 역연령을 비교한 결과, 체력에서 남자는 근력, 순발력, 근지구력, 심폐지구력에서 유의한 차이가 나타났다. 여자는 근력, 평형성, 민첩성, 순발력, 유연성, 근지구력, 심폐지구력에서 유의한 차이가 나타났다. 둘째, 골연령에 따른 유소년의 성별과 연령(11~13세)별로 체력평가의 기초 자료인 골연령 체력 표준지표를 개발하였다.

사관생도들의 혈액성분 및 신체조성 변화 연구 (Studies on Changes of Blood Components and Body Composition in the Cadets)

  • 김동수;정연수;김근수
    • 한국군사과학기술학회지
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    • 제14권1호
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    • pp.139-146
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    • 2011
  • This study investigated physical and physiological changes of normal young adults, who are cadets of the Air Force Academy, have kept long-term physical activities and healthy behavior. The physical and physiological indices were the blood and body composition. Data were collected at the first year period, and then 4th year period from same group of cadets. The amounts of blood components were not changed, but variation among cadets was significantly reduced in the 4th grade period. The red blood cells(RBCs) were significantly reduced and the concentration of hemoglobin(HGB) were significantly increased. The body weight was significantly decreased in the 1st grade period since the body fat was rapidly decreased after the basic military drill, and then it was recovered with building up of the skeletal muscle in the 4th grade period. Asymmetry of the arms was decreased with the increased physical activities and usage of various equipments. The muscular endurance were significantly enhanced in the 4th grade period. The long-term physical activities and healthy behaviors may keep the physical strength through enhanced blood stream and oxygen supply by reduction of the RBCs and increased HGB concentration, and fat and muscle control.

Novel Roaming and Stationary Tethered Aerial Robots for Continuous Mobile Missions in Nuclear Power Plants

  • Gu, Beom W.;Choi, Su Y.;Choi, Young Soo;Cai, Guowei;Seneviratne, Lakmal;Rim, Chun T.
    • Nuclear Engineering and Technology
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    • 제48권4호
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    • pp.982-996
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    • 2016
  • In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs) for radioactive material sampling and stationary tethered aerial robots (STARs) for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.

여자 축구선수를 위한 컴프레션 웨어 설계 (Compression Wear Design for Women's Soccer Players)

  • 박상희
    • 패션비즈니스
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    • 제25권2호
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    • pp.127-142
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    • 2021
  • This study aims to organize the prototype design method of compression wear for women professional soccer players. Despite the excellent performance of female soccer players in world competition, most functional wear has been developed mainly for men, so professional female athletes have fewer choices. Soccer is a sport requiring core and lower body muscle strength, and muscular endurance for long periods of playing or walking on the field. Female soccer players did not differ much in upper body compared to other women, but their lower body had a smaller hip circumference than waist circumference and a larger thigh circumference, requiring compilation considering the physical characteristics and movement of athletes. Female soccer players wear sports bras while playing but regular bras and compression wear during normal exercise because they sweat on under their breast, which irritates sensitive skin. For core muscles in the upper body and to support for thigh and hip muscles in the lower body, the uniform in this study was designed by reducing the body size of a professional female soccer player in her 20s and the actual measurements of commercial compilation software to 81% of the chest circumference, 95% of the waist circumference, and 78% of the hip circumference. The design experiment in this study was a simple exercise and did not produce produce results for long-term exercise and performance improvement, but can be used to design a composition pattern system for other professional female athletes.

Correlations of Physical Fitness Factors, Antioxidant Enzymes, Lipid Peroxidation, Lipid Profiles, Lactate Levels and Cardiovascular Variables in an Exercising Group and Controls

  • Yu, Jae-Ho;Lee, Suk-Min
    • The Journal of Korean Physical Therapy
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    • 제22권3호
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    • pp.61-69
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    • 2010
  • Purpose: This study was designed to investigate correlations between physical fitness, antioxidant enzymes (SOD, CAT, GPX), lipid peroxidation levels (MDA), lipid profiles, lactate levels and cardiovascular variables in an exercising group and a control group. Methods: Twelve healthy young males (Exercise group: 6, Controls: 6). All subjects took physical fitness tests and blood samples were collected while subjects were resting. Results: In the exercise group, there were several significant correlations: between back strength and SOD enzyme levels (r=0.82, p=0.04), back strength and MDA (r=0.94, p=0.00), agility and GPX (r=0.81, p=0.04), and balance and GPX (r=0.81, p=0.04). In the control group, there were significant correlations between: dominant grip strength and MDA (r=-0.84, p=0.03), and agility and GPX (r= -0.82, p=0.04). In the exercise group, there were no significant correlations between physical fitness factors, TC, TG, HDL-C and lactate levels. In the control group, there were significant correlations between: back strength and TG (r=0.88, p=0.01), and agility and HDL-C (r= -0.84, p=0.03). In the exercise group, there were significant correlations between: non-dominant grip strength and SBP (r=0.94, p=0.00), dominant grip strength and SBP (r=0.85, p=0.03), and power and SBP (r=0.82, p=0.04). In controls, there were significant correlations between: dominant grip strength and DBP (r=-0.85, p=0.03), muscular endurance and ST level (r=-0.93, p=0.00), and muscular endurance and HR (r=-0.88, p=0.01). Conclusion: That cardiovascular patients and controls who participated in regular exercise maintained their antioxidant capacity suggests that long-term physical activity can counteract the negative dysfunction that characterizes sedentary lifestyle, probably by maintaining plasma antioxidant defenses and thereby preventing oxidative stress.

The Effect of Alum and Metals on Paper Aging

  • Choi, Kyoung-Hwa;Yoon, Byung-Ho;Lee, Myoung-Ku
    • 펄프종이기술
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    • 제40권5호
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    • pp.42-46
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    • 2008
  • The papers in preserved books and archives experience aging which was affected by a variety of factors. Thus, the studies concerning impacts of those factors on paper aging are required. In this research, a simulation of a short-time accelerated paper aging was conducted in order to examine the effects of acid and metals (alum, copper (II) sulfate, copper (II) chloride, and iron (III) chloride) on the natural paper aging for a long time. As a result of experiments, it is found that both acid and metals have impacts on paper aging. Alum resulted in the significant decrease of pH, brightness, folding endurance, and viscosity of paper. Both copper (II) chloride and iron (III) chloride also resulted in the decrease of brightness, folding endurance, and viscosity of paper. In more detail, paper aging by iron (III) chloride showed much more significant than that by copper (II) chloride. The paper aging in case of copper (II) sulfate coexisting sulfate ion, where metal absorbed moisture was higher than in case of paper treated only by alum. This result indicated that metal catalyzes paper aging by acid. Based on these results, it was revealed that both alum and metal are the major factors in paper aging. In particular, paper aging was far more accelerated in case when acid and metals existed in paper at the same time.

Ferroelectric-gate Field Effect Transistor Based Nonvolatile Memory Devices Using Silicon Nanowire Conducting Channel

  • Van, Ngoc Huynh;Lee, Jae-Hyun;Sohn, Jung-Inn;Cha, Seung-Nam;Hwang, Dong-Mok;Kim, Jong-Min;Kang, Dae-Joon
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.427-427
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    • 2012
  • Ferroelectric-gate field effect transistor based memory using a nanowire as a conducting channel offers exceptional advantages over conventional memory devices, like small cell size, low-voltage operation, low power consumption, fast programming/erase speed and non-volatility. We successfully fabricated ferroelectric nonvolatile memory devices using both n-type and p-type Si nanowires coated with organic ferroelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] via a low temperature fabrication process. The devices performance was carefully characterized in terms of their electrical transport, retention time and endurance test. Our p-type Si NW ferroelectric memory devices exhibit excellent memory characteristics with a large modulation in channel conductance between ON and OFF states exceeding $10^5$; long retention time of over $5{\times}10^4$ sec and high endurance of over 105 programming cycles while maintaining ON/OFF ratio higher $10^3$. This result offers a viable way to fabricate a high performance high-density nonvolatile memory device using a low temperature fabrication processing technique, which makes it suitable for flexible electronics.

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소형 무인항공기 추진용 덕티드팬의 공력특성에 대한 실험적 연구 (Experimental Study on the Aerodynamic Characteristics of the Ducted fan for the Propulsion of a Small UAV)

  • 류민형;조이상;조진수
    • 한국항공우주학회지
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    • 제40권5호
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    • pp.413-422
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    • 2012
  • 덕티드팬을 추진 장치로 사용하는 소형 무인항공기는 도심 및 협소한 공간에서 정찰 및 감시에 사용 가능하며, 프로펠러에 비해 높은 추진 효율과 추력 특성을 나타낸다. 덕티드팬 무인항공기의 운용 거리와 비행 시간을 증가시키기 위해서는 정지 비행 및 전진 비행시의 추력 특성연구가 중요하며 비행 안정성 확보를 위해서는 비정상 3차원 유동 특성 연구가 필수적이다. 본 연구에서는 동익과 정익으로 구성된 덕티드팬의 설계 결과 검증과 안정적인 비행 특성을 확인하기 위해 덕티드팬의 추력 특성과 비정상 3차원 유동장을 계측하였다. 덕티드팬의 정지 및 전진 비행시의 추력 특성은 소형 아음속 풍동의 6분력 밸런스 시스템을 이용하여 측정되었고, 비정상 3차원 유동장은 $45^{\circ}$ 경사열선의 프로브 고정법에 의해 분석되었다. 덕티드팬의 덕트와 정익이 추력특성에 다소 큰 영향을 미치며, 정익에 의해 덕티드팬의 안정적인 비행이 가능함을 확인하였다.

Global Postural Re-education 운동과 일반적인 요부 안정화 운동(LSE)의 비교 -여성노인을 대상으로- (Comparisons between Global Postural Re-education Exercise and Lumbar Stabilization - Focuhing on Eldery Women)

  • 김명철;한슬기;송승현;박정서
    • 대한물리의학회지
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    • 제7권3호
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    • pp.309-318
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    • 2012
  • Purpose : The purpose of this study was to compare 2 different interventions, global postural re-education (GPR) and specific spinal stabilization exercise in the healthy elderly of women. Methods : A total of 28 subjects were randomized into 2 treatment groups: GPR, where therapy involved muscle global chain stretching, or specific spinal stabilization exercise with conventional static stretching (GPR group: n=14, specific spinal stabilization exercise group: n=14). Both groups received exercise intervention 3 times a week for 12-weeks. Results : Outcome was based on trunk endurance, trunk flexibility, Pressure Bio Feedback, Oswestry Disability Index measured immediately before and after intervention. Trunk flexibility, Pressure Bio Feedback, Oswestry Disability Index improved more in GPR group after intervention. There were no differences between the 2 exercise approaches for any of the trunk endurance. Conclusion : As the above results, GPR appear to improve Trunk flexibility, Pressure Bio Feedback, Oswestry Disability Index to the elderly of women. The efficacy of the GPR program used in this study should be further investigated in a long period study and objective outcomes.

Static and dynamic characterization of a flexible scaled joined-wing flight test demonstrator

  • Carregado, Jose;Warwick, Stephen;Richards, Jenner;Engelsen, Frode;Suleman, Afzal
    • Advances in aircraft and spacecraft science
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    • 제6권2호
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    • pp.117-144
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    • 2019
  • High Altitude and Long Endurance (HALE) aircraft are capable of providing intelligence, surveillance and reconnaissance (ISR) capabilities over vast geographic areas when equipped with advanced sensor packages. As their use becomes more widespread, the demand for additional range, endurance and payload capability will increase and designers are exploring non-conventional configurations to meet the increasing demands. One such configuration is the joined-wing concept. A joined-wing aircraft is one that typically connects a front and aft wings in a diamond shaped planform. One such example is the Boeing SensorCraft configuration. While the joined-wing configuration offers potential benefits regarding aerodynamic efficiency, structural weight, and sensing capabilities, structural design requires careful consideration of elastic buckling resulting from the aft wing supporting, in compression, part of the forward wing structural loading. It has been shown already that this is a nonlinear phenomenon, involving geometric nonlinearities and follower forces that tend to flatten the entire configuration, leading to structural overload due to the loss of the aft wing's ability to support the forward wing load. Severe gusts are likely to be the critical design condition, with flight control system interaction in the form of Gust Load Alleviation (GLA) playing a key role in minimizing the structural loads. The University of Victoria Center for Aerospace Research (UVic-CfAR) has built a 3-meter span scaled and flexible wing UAV based on the Boeing SensorCraft design. The goal is to validate the nonlinear structural behavior in flight. The main objective of this research work is to perform Ground Vibration Tests (GVT) to characterize the dynamic properties of the scaled flight vehicle. Results from the experimental tests are used to characterize the modal dynamics of the aircraft, and to validate the numerical models. The GVT results are an important step towards a safe flight test program.