• 제목/요약/키워드: Tilt angle

검색결과 629건 처리시간 0.035초

운동침대 틸트 각도 변화에 따른 노인의 승모근, 다열근 및 슬괵근 근육의 생리학적 특성 변화 연속 증례 연구 (Changes in Physiological Characteristics of Trapezius, Multifidus and Hamstring Muscles According to Tilt Angle of Exercise Bed in Elderly)

  • 김정진
    • 정형스포츠물리치료학회지
    • /
    • 제14권2호
    • /
    • pp.127-133
    • /
    • 2018
  • Purpose: This study investigated the effects of changing the tilt angle of the exercise bed on physiological characteristics of trapezius, multifidus, and hamstring muscle function. Methods: Twenty elderly who complains of back and lumbar pain or discomfort participated in this study (average age: $64.70{\pm}4.55$ years). The physiological characteristics, including muscle tone (F), dynamic stiffness (S), and elasticity (D) of trapezius, multifidus, and hamstring muscles were measured by a Myoton device at three tilt angles (0, 15, and 30 degrees) during exercise. Results: The muscle tone, dynamic stiffness, and elasticity of the right trapezius and left hamstring muscle showed significant differences (p<0.05) according to exercise bed tilt angle, while the other muscles showed no significant differences. Conclusions: Our results demonstrate that physiological characteristics of the upper and lower extremity muscles are affected ipsilaterally, according to the tilt angles of the exercise bed.

A Novel ECB cell using bend structure for Nematic Liquid Crystal on Rubbed Polyimide Surface

  • Hwang, J.Y.;Kim, K.W.;Seo, D.S.
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
    • /
    • pp.1137-1141
    • /
    • 2004
  • In this paper, we have improved a novel ECB mode using bend structure with high tilt angle in the unique condition by Hot plate equipment. The new control of tilt angle for nematic liquid crystal (NLC) with negative and positive dielectric anisotropy on the rubbed homeotropic polyimide (PI) using baking method by Hot plate equipment was investigated. LC tilt angle decreased with increasing baking temperature and time. We suggest that the development of the novel ECB cell using control of tilt angle on the homeotropic surface is a promising technique for the achievement of fast response time and high contrast ratio.

  • PDF

태양열발전용 흡수기 설게 및 열손실 특성실험 (Experimental Study on Heat Losses from Receiver of Solar Thermal Power)

  • 김종규;강용혁;김진수;이상남;유창균;윤환기
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 한국신재생에너지학회 2007년도 춘계학술대회
    • /
    • pp.672-675
    • /
    • 2007
  • Experimental data are presented which describe heat losses of cavity type receiver in wind tunnel. Experiments are conducted at various conditions such as the heater temperature in cavity changes from 300, 400, and 500 oC, wind speed in tunnel from 2 to 8 m/s, and four different tilt angle of 30, 50, 70, 90o. The power consumption including temperature, voltage and current for each experimental conditions are measured and stored in data logger at everyone second interval. The experimental results show that heat losses increase with increasing wind speed and with tilt angle. However, heat losses for the tilt angle of 70 and 90o is almost same at each heater temperature. In addition, the effects of natural convection in combined convection heat losses vary in according to the tilt angle.

  • PDF

Pyramidal reaction wheel arrangement optimization of satellite attitude control subsystem for minimizing power consumption

  • Shirazi, Abolfazl;Mirshams, Mehran
    • International Journal of Aeronautical and Space Sciences
    • /
    • 제15권2호
    • /
    • pp.190-198
    • /
    • 2014
  • The pyramidal reaction wheel arrangement is one of the configurations that can be used in attitude control simulators for evaluation of attitude control performance in satellites. In this arrangement, the wheels are oriented in a pyramidal configuration with a tilt angle. In this paper, a study of pyramidal reaction wheel arrangement is carried out in order to find the optimum tilt angle that minimizes total power consumption of the system. The attitude control system is analyzed and the pyramidal configuration is implemented in numerical simulation. Optimization is carried out by using an iterative process and the optimum tilt angle that provides minimum system power consumption is obtained. Simulation results show that the system requires the least power by using optimum tilt angle in reaction wheels arrangement.

태양열 집광 흡수기 입구의 개방비와 경사각도에 따른 열유체 유동에 관한 수치해석 (A Numerical Analysis on Thermal and Fluid in Solar Concentration Absorber with Tilt Angle and Opening Ratio of Absorber Entrance)

  • 이상철;이용훈;최석천;신유식;정효민;정한식
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2003년도 춘계학술대회
    • /
    • pp.1485-1490
    • /
    • 2003
  • This paper is the analysis of thermal and fluid in solar concentration absorber with various tilt angle and opening ratio of absorber entrance. The purpose of this study is to develop optimum solar concentration absorber, and the parameters for the study are the opening ratio of absorber entrance and the tilt angle. The aspect ratio of absorber was fixed at 0.64, and opening ratio was changed from 0.1 to 1.0. The finite volume method with SIMPLE computational algorithm are used and analyzed the heat transfer in absorber inside walls.

  • PDF

가속도계와 자이로스코프를 이용한 평면의 경사각 추정 (Tilt Angle Estimation of Plane with a Pair of Accelerometers and a Gyroscope)

  • 강민식
    • 한국소음진동공학회논문집
    • /
    • 제23권11호
    • /
    • pp.966-972
    • /
    • 2013
  • Measurement or estimation of tilt angle is necessary for balancing robot such as Segway which is considered as a next generation transportation vehicle. However, it requires high-cost accurate sensors to hold balancing during stationary and moving situations. In this paper, a tilt angle estimation of a plane rotating in a vertical plane using low-cost sensors. Estimation using a set of 2-axis orthogonal accelerometers along with an inaccurate rate gyro has been considered. Feasibility and performance of the proposed technique has been verified through some experimental results.

각도센서를 사용한 지상발사플랫폼의 후류편향판 구동 제어에 관한 연구 (The Study on the Control of the Plume Deflection Panel of the Ground Launching Platform Using a Tilt Angle Sensor)

  • 최병창
    • 한국군사과학기술학회지
    • /
    • 제25권5호
    • /
    • pp.522-529
    • /
    • 2022
  • In this paper, an experimental study on the control of the plume deflection panel(PDP) with a support jack of the ground launching platform using a tilt angle sensor is described. To overcome the disadvantages of the existing PDP control without a support jack using a limit sensor, the control algorithm using a tilt angle sensor and the ferroelectric RAM in the Launcher Control Unit for recognizing the contact with the ground in an abnormal operation is proposed to control the PDP in various operation environments. Finally, the proposed algorithm can be well applied for not only heavy-load launching platforms but also any other similar systems.

혼합된 polymer에서의 틸트 감소 효과를 이용한 VA-$\pi$ mode LCD의 전기광학 특성 (EO Characteristics in the Vertical Alignment (VA)-$\pi$ mode LCD Using the Tilt Angle Decrease Effect on the Blended Polymer)

  • 이경준;황정연;서대식
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2003년도 제5회 학술대회 논문집 일렉트렛트 및 응용기술연구회
    • /
    • pp.53-56
    • /
    • 2003
  • Blending effects for generating a pretilt angle in nematic liquid crystal (NLC) with negative dielectric anisotropy on the blended polyimide (PI) of homeotropic and homogeneous alignment surface were studied. Also, we investigated the EO performances for the advanced VA-$\pi$ cell using this homeotropic blended PI surface. A many decrease of tilt angle on the polymer surface to blend homeotropic PI and homogeneous PI with side chain type was measured, and the tilt angle decreased as blended ratio and rubbing strength increase. The blended effects for generating a pretilt angle were clearly observed, and the many decrease of tilt angle can be achieved by using the blended PI surface. The electro-optical (EO) characteristics using the advanced VA-$\pi$ cell using the homeotropic blended PI surface than that of conventional VA cell can be improved. We suggest that the developed advanced VA-$\pi$ cell on a homeotropic blended PI surface is a promising technique for the achievement of a fast response time, and a high contrast ratio.

  • PDF

수직 복합폴리머 표면을 이용한 Advanced VA-π cell의 전기 광학 특성 (EO Characteristic in the Advanced Vertical Alignment (VA)- π Cell a Homeotropic Blended Polymer)

  • 황정연;이경준;조용민;서대식
    • 한국전기전자재료학회논문지
    • /
    • 제16권9호
    • /
    • pp.826-832
    • /
    • 2003
  • Blending effects for generating a pretilt angle in nematic liquid crystal (NLC) with negative dielectric anisotropy on the blended polyimide (PI) of homeotropic and homogeneous alignment surface were studied. Also, we investigated the EO performances for the advanced VA- $\pi$ cell using this homeotropic blended PI surface. A many decrease of tilt angle on the polymer surface to blend homeotropic PI and homogeneous PI with side chain type was measured, and the tilt angle decreased as blended ratio and rubbing strength increase. However, a small decrease of tilt angle on the polymer surface to blend homeotropic PI and homogeneous PI with main chain type was measured. The blended effects for generating a pretilt angle were clearly observed, and the many decrease of tilt angle can be achieved by using the blended PI surface. The electro-optical (EO) characteristics using the advanced VA- $\pi$ cell using the homeotropic blended PI surface than that of conventional VA cell can be improved. We suggest that the developed advanced VA-$\pi$ cell on a homeotropic blended PI surface is a promising technique for the achievement of a fast response time, and a high contrast ratio.

Effects of Verbal Cue for Scapular Depression During Scapular Posterior Tilt Exercise on Scapular Muscle Activities and Clavicular Tilt Angle in Subjects With Rounded Shoulder Posture and Upper Trapezius Myofascial Pain

  • Choi, Sil-ah;Cynn, Heon-seock;Shin, A-reum;Kim, Da-eun
    • 한국전문물리치료학회지
    • /
    • 제24권3호
    • /
    • pp.30-39
    • /
    • 2017
  • Background: Scapular posterior tilt (SPT) is important in the prevention of abnormal scapular movement and pain during elevation of the arm. However, previous studies have overlooked increased upper trapezius (UT) muscle activity interrupting the normal force couple of scapular motion and compensation of levator scapulae (LS) muscle activated simultaneously with UT during SPT exercise. Objects: The purpose of this study was to compare the effects of modified SPT with depression exercise versus SPT exercise on serratus anterior (SA), lower trapezius (LT), UT, and LS muscle activities and the clavicular tilt angle, in subjects with rounded shoulder posture (RSP) and myofascial pain in the UT muscle region. Methods: Eighteen subjects with RSP were recruited and randomly allocated to 2 groups; 9 in the SPT group and 9 in the SPT with depression group. All subjects met the specific RSP criteria and had myofascial pain of UT region. Depending on the allocated group, subjects performed the assigned SPT exercise and EMG data were recorded during the each exercise. Clavicular tilt angle was defined as the angle between the line joining the medial and lateral end of the clavicle and a horizontal line. Results: The SA muscle activity was significantly greater in SPT with depression than with SPT exercise (p<.05). The UT, LS muscle activity and the clavicular tilt angle was significantly lower in SPT with depression than with SPT exercise (p<.05). Conclusion: These findings were insightful because the potential risk of pain from overactivation of the UT and LS was considered, in contrast with SPT exercise. SPT with depression exercise can be implemented as an effective method to facilitate scapular muscle activity for stability and to prevent myofascial pain in the neck and shoulder.