• Title/Summary/Keyword: experimental device

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A Portable Skin Elasticity Measuring Device Based on Indentation Method Using Piezoelectric Effect (압전효과를 이용한 압인방식의 휴대용 피부탄력 측정장치)

  • Park, Jun-Young;Kim, Myoung Nam
    • Journal of Korea Multimedia Society
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    • v.25 no.9
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    • pp.1307-1315
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    • 2022
  • In this paper, we proposed and developed a new portable skin elasticity measuring device based on the indentation method using piezoelectric effect. The proposed device is designed to minimize the uncertainty caused by the layer structure of the skin when measuring the elasticity of the skin. And, we developed a piezoelectric-based thin-film pressure sensor that can measure quantitatively and quickly during repeated measurement as a device sensor. To confirm the effectiveness of the proposed measuring device, it was compared with the experimental results of the conventional measuring devices under the same experimental conditions, and statistical correlation analysis was performed between the experimental data of the proposed measuring device and the experimental data of the conventional measuring devices. As a result of the correlation analysis, it was confirmed that the proposed measuring device had a high correlation with the conventional measuring devices. Therefore, it was confirmed that the proposed skin elasticity measuring device was effective.

A Study on the Improvement of Efficiency of Heat Transfer of Double Pipe Heat Exchanger with Helical Insert Device on Cooling of a Fuel Cell (연료전지 냉각용 헬리컬 인서트디바이스 이중관열교환기의 열전달 성능 향상에 관한 연구)

  • CHO, Dong-Hyun
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.6
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    • pp.1872-1879
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    • 2015
  • The present study was conducted on the improvement of the heat transfer performance of double pipe heat exchangers with helical insert device. Double pipe heat exchangers with helical insert device were studied for improvement of the heat transfer performance of double pipe heat exchangers with helical insert device and plain double pipe heat exchangers were also studied to comparatively analyze heat transfer performance. Experimental results were derived on changes in the Reynold's numbers of the cooling water flowing in helical and plain double pipe heat exchangers and changes in the heat flux of the air. Thereafter, to verify the reliability of the experimental results, the theoretical total energy and the experimental total energy were comparatively analyzed and the following results were derived. The thermal energy of the calorie lost by the hot air and that of the calorie obtained by the cooling water were well balanced. The experiments of plain double pipe heat exchangers and double pipe heat exchangers with helical insert device were conducted under normal conditions and the theoretical overall heat transfer coefficient value and the experimental overall heat transfer coefficient value coincided well with each other. In both plain double pipe heat exchangers and double pipe heat exchangers with helical insert device, heat transfer rates increased as the cooling water flow velocity increased. Under the same experimental conditions, the heat transfer performance of double pipe heat exchangers with helical insert device was shown to be higher by approximately 1.5 times than that of plain double pipe heat exchangers.

Experimental Study on Active Control of Building Structures by Feedback Variables (피드백 변화에 따른 건물의 능동제어 실험)

  • 민경원
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1998.10a
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    • pp.286-294
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    • 1998
  • This paper presents an experimental study on the performance of the active damper device by feedback variables. The damper is a mass-typed active device, which exerts the inertia control force on the building by AC servo motor. The control performance is experimentally analyzed considering the building response and the control force. It is found that the building response is greatly reduced by mass-typed device under the resonant and earthquake loading. Also, the experimental results show that the velocity feedback reduces the building responses with the smallest amount of control force than any other feedback variables.

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Effects of NMES and Horseback Riding Using a Robotic Device on the Trunk Muscle Activity and Gross Motor Function in Children with Spastic Diplegia

  • Park, Shin-Jun;Youn, Pong-Sub
    • The Journal of Korean Physical Therapy
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    • v.30 no.4
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    • pp.123-128
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    • 2018
  • Purpose: This study examined the effects of neuromuscular electrical stimulation (NMES) and horseback riding using a robotic device on the trunk muscle activity and gross motor function in children with spastic diplegia. Methods: Children with spastic diplegia were divided into two groups: an experimental group (NMES and horseback riding using a robotic device [n=10]) and a control group (placebo NMES and horseback riding using a robotic device [n=10]). Each group received general physical therapy and occupational therapy. Each intervention involved the administration of NMES for 15 minutes and horseback riding using robotic device therapy for 15 minutes three times a week for 4 weeks. The evaluation included both the rectus abdominis muscles (RA), external oblique muscles (EO), thoracic paraspinal muscles (TP), and lumbar paraspinal muscles (LP) activity and GMFM. Results: The RA, EO, TP, and LP muscle activity, GMFM C, D, and E were increased significantly in the experimental and control groups. A significant increase in both the TP muscle activity and GMFM D was observed in the experimental group compared to the control group. Conclusion: This study showed that horseback riding using a robotic device is an effective intervention for trunk muscle activity and GMFM in children with spastic diplegia. However, if NMES is added to the back muscles, it is possible to further increase the thoracic paraspinal muscle activity and standing ability.

Changes in the quality of chest compressions applying a digital sensor device (디지털 센서 장비를 적용한 가슴 압박의 질 변화)

  • Yang, Hyun-Mo
    • The Korean Journal of Emergency Medical Services
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    • v.18 no.1
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    • pp.107-116
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    • 2014
  • Purpose : The purpose of this study is to demonstrate the effectiveness of using a digital sensor device during CPR by analyzing the results from that chest compressions with a digital sensor device are applied to cardiac arrest patients. Methods : This study analyzed the results from the experiment that 42 people were selected randomly among Korean 119 rescuers, and they divided into the experimental group using a digital sensor device and the control group only using their hands, then they had been observed to conduct chest-compressions to mannequins for 10 minutes. Results : The results were found that compression depth in both the control and experimental group was gradually decreased over time, but the experimental group not only kept the depth but also maintained the speed of chest-compressions close to 100 times a minute. In addition, due to the use of the digital sensor device, the insufficient recoil ratio of chest-compressions was significantly reduced. Conclusion : The results show that conducting chest-compressions with a digital sensor device keeps the compression-death, maintains the speed of chest-compression properly and makes the insufficient relaxation ratio of chest-compressions reduce significantly.

Development of device measuring very high torque via torque arm with attached load cells (로드셀과 토크암을 이용한 대용량 토크 측정장치 개발에 관한 연구)

  • Lee, Y.B.;Han, S.H.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.7 no.1
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    • pp.6-10
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    • 2010
  • A measurement of very high torque for track drive unit in construction equipment is usually in difficulties due to the requirement of a torque meter with high capacity, and the limitation of geometry for an experimental set-up. To improve the troublesome problem, a new device was proposed, where a torque transmitted through the torque arm can be measured by load cells attached at each torque arm. The experimental set-up of the new device was carried out in order to measure the torque values for a mechanical feedback type planetary gear box, in which the power flow circulates itself in a closed-loop. The new device enables to measure torque values of 60,000Nm. Additionally, the measured values were estimated statistically in the aspect of their repeatability and reproducibility, so that an acceptable behaviour as a measuring device can be confirmed.

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Experimental Results on Kinematic Calibration of Parallel Manipulator using 6 DOF Measurement Device (6자유도 측정 장치를 이용한 병렬 기구의 캘리브레이션 실험 결과)

  • Rauf Abdul;Pervez Aslam;Kim Hyun-Ho;Ryu Je-Ha
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.197-203
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    • 2005
  • This paper presents kinematic calibration of parallel manipulators with partial pose measurements using a device that measures a rotation of the end-effector along with its position. The device contains an LVDT, a biaxial inclinometer, and a rotary sensor and facilitates automation of the measurement procedure. The device is designed in a modular fashion and links of different lengths can be used. The additional kinematic parameters required for the measurement device are discussed, kinematic relations are derived, and cost function is established to perform calibration with the proposed device. The study is performed for a six degree-of-freedom(DOF) fully parallel HexaSlide Mechanism(HSM). Experimental results show significant improvement in the accuracy of the HSM.

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A Study on Improvement of Industrial Hood in Ventilation System for Elimination of Harmful Material and Dust (유해물질 및 공업용 분진 제거를 위한 산업용 후드 개선에 관한 연구)

  • Kim, Young-Sun;Oh, Yool-Kwon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.4
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    • pp.238-244
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    • 2008
  • This study investigates on the improvement of inhalation effect of hood which attached new device named as "gas-guide-device" in local exhaust ventilation system for the effective elimination of harmful material and dust in manufacturing factory. The gas-guide-device having a diamond shape is composed of width (b) and two sides of a device (X, Y) and its size is selected the industrial hood under application in manufacturing factory after due consideration. In order to investigate the effect of gas-guide-device, numerical and experimental study is performed that the flow velocity is calculated and is measured by a commercial program "COMSOL $Multiphysics^{TM}$" and a hot wire type of anemometer, respectively. The numerical and experimental results are revealed is a similar pattern and flow velocity has improved to hood attached gas-guide-device. Also, the numerical method and result is also verified the dependance. Moreover, the optimum shape and size of gas-guide-device is revealed that the width (b) and the ratio of two sides of gas-guide-device (X, Y) has 125mm and 4 to 6.

The Effects of the Band Type Foot Drop Device (밴드형 첨족예방기구의 효과와 유용성)

  • Kang Hyun-Sook;Kim Won-Ock;Lee Hya-Sook
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.7 no.3
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    • pp.391-400
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    • 2000
  • A long-term bed rest results in an inevitable foot drop. Yet preventive device such as a foot board and high-neck tennis shoes, are not widely used. This study was conducted to compare the effects of a pillow-type foot board with that of the band-type device. The band-type device of a resonable price is designed for an effective prevention of foot drop, and the convenience for it use. Among the non-equivalent control group design, foot drop preventive effects, usefulness of the device, as well as its cost effectiveness were examined. The study was carried out for four months from December 1999, and its subject had been patients and nurses of two intensive care units at K medical center in Seoul. According to the study purpose, the data collected were analyzed by $x^2-test$ and t-test. The results are as follow : 1. The ROM of ankle joint is promoted in the experimental group with a band-type device comparing the control group with a pillow type one. Dorsiflexion is particularly increased in the experimental group as compared with the control group, while planterflexion hardly shows any change. 2. The usefulness score of the experimental group nurses using the band-type device (23.97) is higher than that of the control group nurses (18.88). 3. In an aspect of the unit production cost, band-type devices are low-priced compare with pillow-type or other foot board (wooden) or high-neck tennis shoes. In summary, the newly developed band-type device is both useful and preventive for a foot drop. It is also desirable regarding to the production cost and the cost effectiveness. This fact proves that the new anti-foot drop device could be practical both for clinical care and home care. Yet the results were obtained by some subjects, it should be used after a further examination. More effective nursing intervention could be observed throughout general studies, including proper positioning and foot and ankle exercises which are the important variables of the foot drop prevention.

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Theoretical and Experimental Analysis of Back-Gated SOI MOSFETs and Back-Floating NVRAMs

  • Avci, Uygar;Kumar, Arvind;Tiwari, Sandip
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.4 no.1
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    • pp.18-26
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    • 2004
  • Back-gated silicon-on-insulator MOSFET -a threshold-voltage adjustable device-employs a constant back-gate potential to terminate source-drain electric fields and to provide carrier confinement in the channel. This suppresses shortchannel effects of nano-scale and of high drain biases, while allowing a means to threshold voltage control. We report here a theoretical analysis of this geometry to identify its natural length scales, and correlate the theoretical results with experimental device measurements. We also analyze experimental electrical characteristics for misaligned back-gate geometries to evaluate the influence on transport behavior from the device electrostatics due to the structure and position of the back-gate. The backgate structure also operates as a floating-gate nonvolatile memory (NVRAM) when the back-gate is floating. We summarize experimental and theoretical results that show the nano-scale scaling advantages of this structure over the traditional front floating-gate NVRAM.