• Title/Summary/Keyword: Dynamic tape

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Theoretical Analysis of Carbon Nanotube Actuators (탄소나노튜브 작동기의 이론적 해석)

  • Park C.H.;Park H.C.;So H.K.;Jung B.B.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.927-931
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    • 2005
  • Carbon nanotube actuator, working under physical conditions (in aqueous solution) and converting electrical energy into mechanical energy directly, can be a good substitute for artificial muscle. The carbon nanotube actuator simulated in this paper is an isotropic cantilever type with an adhesive tape which is sandwiched between two single-walled carbon nanotubes. For predicting the static and dynamic characteristic parameters, the analytical model for a 3 layer bimorph carbon nanotube actuator is developed by using Euler-Bernoulli beam theory. The governing equation and boundary conditions are derived from energy principles. The induced displacements of the theoretical model are presented in order to investigate the performance of the carbon nanotube actuator with different control voltages. The developed model presents invaluable means for designing and predicting the performance of carbon nanotube actuator that can be used in artificial muscle applications.

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Comparison of Torsional Vibration Measurement Techniques

  • Verrecas, B.;Janssens, K.;Britte, L.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2012.04a
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    • pp.441-441
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    • 2012
  • Noise and vibration performance plays an important role in the development of rotating components, such as engines, drivelines, transmission systems, compressors and pumps. The presence of torsional vibrations and other specific phenomena require the dynamic behaviour of systems and components to be designed accurately in order to avoid comfort and durability related problems. This paper provides an overview of the instrumentation and challenges related to torsional vibration testing. The accuracy and performance of five measurement techniques (high-speed incremental encoder, dual beam laser interferometer, zebra tape, zebra disc, direct pulse measurements with magnetic probe) is investigated by measurements on a Fiat Punto 1.4 liter engine. The potential sources of error are discussed to explain the inaccuracies of each technique.

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DC voltage-current characteristics of a Bi-2223 tape in AC magnetic fields (교류자장에 대한 Bi-2223테이프의 직류전압-전류 특성)

  • Huh, Dae-Haing;Ryu, Kyung-Woo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05b
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    • pp.123-126
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    • 2003
  • 고온초전도테이프의 전력부야 응용에서 자화손실과 함께 매우 중요한 통전손실에 대한 실험적 조사 연구를 한 결과, 외부자장이 커짐에 따라서 직류전압이 급격히 증가하였으며, 자장의 세기가 동일할지라도 교류인 경우가 직류인 경우보다 대단히 크다. 그리고 외부교류자장에 대한 직류전압-전류 특성으로부터 정의되는 동저항 또한 외부교류자장의 세기에 따라서 상이하지만 테이프의 임계전류에서 전기저항$(3.7\;{\mu}{\Omega}/m)$과 비교하여 작게는 수배에서부터 크게는 수백 배까지 증가한다.

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Surface Properties of Unsaturated Polyester Resin/Siloxane-ester Copolymer Blends (불포화폴리에스테르 수지/실록산-에스테르 공중합체 블렌드의 표면특성)

  • Chang, Young-Wook;Cheong, Yongjoo;Kim, Dongkook;Jung, Jin-Soo
    • Applied Chemistry for Engineering
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    • v.10 no.1
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    • pp.93-97
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    • 1999
  • In order to lower the surface energy of unsaturated polyester(UPE) resin, small amount of siloxane-ester copolymers were incorporated. The copolymers were synthesized by a condensation polymerization using ethylene glycol and hydroxy termintated polydimethylsiloxane as diols and maleic anhydride and phthalic anhydride as dibasic acids. The modified UPE resin surface was characterized by dynamic contact angle (DCA), peel strength measurements of pressure sensitive adhesives and X-ray photoelectron spectroscopy(ESCA). As the copolymer content in the blend and PDMS content in the copolymer are increased, both advancing and receding contact angles against water are increased. The strength required to peel-off the pressure sensitive adhesive tape from the modified UPE resin decreased dramatically with the addition of the copolymer. ESCA results indicated that polydimethylsiloxane segments are predominated at the outer surface of the modified UPE resin.

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The Effect of Rhythmic Dance Movement Training on the Gait Length, Dynamic Valance, Depression, Quality of Life (비디오를 통한 율동적 동작훈련이 노인의 보장, 보행속도, 동적균형, 우울 및 삶의 질에 미치는 효과)

  • Roh, Kook-Hee
    • The Korean Journal of Rehabilitation Nursing
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    • v.6 no.1
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    • pp.70-78
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    • 2003
  • This study was a quasi-experimental study of nonequivalent control group pretest-posttest design to investigate the effect of rhythmic dance movement training on the physical and psychological functions of the elderly. The data were collected from November, 2001 to February, 2002. The subjects for this study were 34 elderly who was over 65 years old and was living in J city. The elderly selected for this study were: free from heart and pulmonary disease and not regular exercise. The rhythmic dance movement training in watching video tape was rhythmic dance movement and education and supportive care. The rhythmic dance movement was 40-60 intensity, 8 weeks' period, three times a week, 60 minutes a day. The data were analysed by $X^2$-test, paired t-test and unpaired t-test and ANCOVA through SAS/PC program. The results of the study were as follows: 1. There was insignificant difference in the gait length experimental and control group. 2. There was significant difference in the gait speed between the two groups. 3. There was significant difference in the dynamic valance between the two groups. 4. There was no significant difference in the depression between the two groups. 5. There was no significant difference in the Quality of life between the two groups. As shown above, the results of the 8 weeks' rhythmic movement program for the elderly produced positive effects on gait speed, dynamic valance. And this program was expected that it was more effective in different intervention period, verified program. Also it was needed follow study.

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Flexural behavior of precast concrete wall - steel shoe composite assemblies with dry connection

  • Wu, Xiangguo;Xia, Xinlei;Kang, Thomas H.K.;Han, Jingcheng;Kim, Chang-Soo
    • Steel and Composite Structures
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    • v.29 no.4
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    • pp.545-555
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    • 2018
  • This study aimed to investigate the flexural behavior of precast concrete (PC) wall - steel shoe composite assemblies with various dry connection details at mid-span. Flexural tests were performed for five scenarios. Test parameters included the width of test specimens, arrangement of steel shoe connectors, and use of structural adhesive or waterproof tape at the mid-span joint. The test results showed that the PC wall - steel shoe composite assemblies joined at mid-span showed flexural damage patterns combined with rotational deformation, and the structural performance was satisfactory regardless of the arrangement of steel shoe connectors. Considering the two deformation components (flexural deformation by bending and rotational deformation due to joint opening), a theoretical model was proposed to analyze flexural strength and joint opening, and the simple model gave good predictions with acceptable accuracy.

Basic Characteristic Verification of High-damping Laminated Solar Panel with Viscoelastic Adhesive Tape for 6U CubeSat Applications (점탄성 테이프를 적용한 6U 큐브위성용 고댐핑 적층형 태양전지판의 기본 특성 검증)

  • Kim, Su-Hyeon;Kim, Hongrae;Oh, Hyun-Ung
    • Journal of Aerospace System Engineering
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    • v.15 no.1
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    • pp.86-94
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    • 2021
  • PCB-based deployable solar panel is mainly used for CubeSat due to its lightweight and easy of electrical connection. However, as the size of solar panel increases, there is a limit to ensuring the structural safety of solar cells due to excessive dynamic displacement under launch vibration environment. In previous mechanical designs, for the minimization of dynamic deflection, panel stiffness is increased by applying additional stiffeners made of various materials such as aluminum or composite. However, it could have disadvantages for CubeSat design requirements due to limited mass and volumes. In this study, a high-damping 6U solar panel was proposed. It had superior damping characteristic with a multi-layered stiffener laminated with viscoelastic acrylic tapes. Basic characteristics of this solar panel were measured through free-vibration tests. Design effectiveness of the solar panel was validated through qualification-level launch vibration test. Based on test results, vibration characteristics of a typical PCB solar panel and the high-damping laminated solar panel were predicted and a comparative analysis was performed.

Effect of foam roller, kinesiotaping and dynamic stretching on gait parameters with induced ankle muscle fatigue

  • Suh, Hye Rim;Lee, Su-Young
    • Physical Therapy Rehabilitation Science
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    • v.7 no.3
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    • pp.127-133
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    • 2018
  • Objective: The purpose of this study was to investigate the effects of foam roller (FR) stretching, kinesiotaping (KT), and dynamic stretching (DS) on gait parameters after inducing muscle fatigue in the ankle joint. Design: Cross-sectional study. Methods: The subjects were thirty healthy young adults between the ages of 20 and 31 years at Baekseok University who voluntarily participated in this study. The participants were randomly assigned to either the FR group, KT group, or the DS group after inducing muscle fatigue of the ankle joint. Fatigue induction of the ankle joint muscles was performed by alternating a heel up and down exercise with the standing posture on the ground. The speed was maintained at 40 beats/minute using a metronome. Subsequently, the respective intervention was applied to each group. Gait parameters were measured before and after ankle muscle fatigue induction, and after intervention using the GAITRite system. One-way ANOVA was used to compare gait parameters among groups, while repeated measures ANOVA was used to compare gait parameters within each intervention group. Results: The FR group increased significantly in velocity, step length, and stride length except for cadence after intervention compared to after ankle muscle fatigue induction (p<0.01). Furthermore, the KT group showed significant increases in velocity, cadence, step length, and stride length after intervention, especially in cadence group (p<0.05). All intervention groups showed significant increases in stride length after intervention, especially the DS group (p<0.05). Conclusions: Therefore, we suggest that KT, FR, and DS can be an effective intervention on gait parameters when the ankle joint is unstable and injured.

Effectiveness of Home Health Care Service for Elders after Spinal Surgery

  • Jun, Myunghee;Jung, Ji Young
    • Journal of Korean Academy of Nursing
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    • v.42 no.7
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    • pp.1009-1018
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    • 2012
  • Purpose: This study was done to evaluate effectiveness of home healthcare services (HHCS) specialized for elders who received spinal surgeries. Methods: A non-equivalent control group pre-post test quasi-experimental study was performed. HHCS was developed based on the Rice model of dynamic self-determination for self-care. For data collection, a control group (n=23) and an experimental group (n=23) were selected by matching age, BMI, pain, general characteristics and type of spine surgery. Measurement tools to evaluate uncertainty and knowledge were developed by the authors. The Numeric Rating Scale (NRS) and Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) were used to evaluate pain levels. Muscular strength in the legs was measured using a digital muscle tester and tape ruler. Questionnaires were used to evaluate disability in performing ADL and psychological distress levels. Results: The experimental group showed significant decrease in uncertainty (p=.028), increased knowledge (p=.038), and partially decreased pain (p=.003-.331). Partial muscle strength increased significantly (p=.021-.644). Disability in performing ADL and psychological distress in the experimental group decreased significantly compared to control group (p=.002, p=.004). Conclusion: Results indicate HHCS is an efficient home care nursing program for these elders. Further experimental studies with larger samples are required to confirm effects of HHCS.

Three Dimensional Dynamic Analysis of High-Tc Superconducting Revolving Field Type Synchronous Motor (고온초전도 회전계자형 동기전동기의 3차원 동특성 해석)

  • Lee, Sang-Jin
    • Proceedings of the KIEE Conference
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    • 1999.11b
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    • pp.438-441
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    • 1999
  • One of the most important aspect in developing High-Tc Superconducting Synchronous Motor is producing high-Tc superconducting tapes that withstand the amount of currents that is needed to run the motor with stability. The purpose of this paper is to find the magnetic field distribution inside the motor in order to find out if the high-Tc superconducting tapes operate stably in actual motor operation. With this goal, magnetic field distribution in a detailed model of the actual motor was analyzed through F.E.M. By analyzing the field distribution acquired through the computer simulation, it has been observed whether the high-Tc superconducting tape maintains its superconductivity in actual motor operation. Also, the effects of the flux damper on the motor's operational characteristics and the magnetic field distribution have been analyzed. As a result, it has been proved that the high-Tc superconducting tapes can withstand 600 A turns which is required by the previous simulation aimed at developing this motor. It has also seen that the flux damper reduces armature reactance during the motor operation and change of load, helping the stable motor operation.

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