• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.698-702
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• 2013

This paper considers the vertical pumps resonance and soundness. Normally large vertical pump's rotating speed is low, so the low natural mode can make a resonance on the motor and motor stand assembly. The pump resonance makes a very high vibration and trouble on the pump systems. Thus to avoid pump resonance when the pump is on the resonance region, we give the added mass method and evaluate the structure soundness by computer simulation and test on the site. Furthermore we evaluate the modal sensitivity and expect running conditions by the using ISO10814.

• PNF and Movement
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• v.9 no.1
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• pp.31-38
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• 2011

Purpose : Sit-to-stand (STS) is one of the important activities of daily living (ADL) and each of its parameters is used frequently. This study aimed to examine the influence of different seat height on performance time and floor reaction force strength during an STS movement. Methods : Fifteen young-adult male subjects participated in this study. The subjects were divided into three groups based on lower leg length. Subjects performed an STS movement twice from chairs at height adjusted by the lower leg length of each subject. To examine the influence of the chair seat height, ground reaction forces during a STS performed with 3 chair heights adjusted to each subjects lower leg length were compared. Results : Vertical ground reaction force and time during an STS movement were measured to evaluate. Parameters regarding ground reaction force were selected for analyses. Significant differences were found in ground reaction force at G1 was greater than G2 and G3. Conclusion : The STS movement achievement strategy differed since chair seat height changes relatively by the difference in lower leg length. When conducting the ability to achieve STS movement rating test, chair seat height considering each subject's lower leg length may be needed.

• Physical Therapy Korea
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• v.23 no.3
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• pp.40-47
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• 2016

Background: Assessments of Sit-to-Stand (STS) and gait functions are essential procedures in evaluating level of independence for the patients after stroke. In a previous study, we developed the software to analyze center of pressure (COP) in standing position on Wii Balance Board (WBB). Objects: This purpose of this study is to measure test-retest reliability of ground reaction forces, COP and time using WBB on STS and gait in healthy adults. Methods: Fifteen healthy participants performed three trials of STS and gait on WBB. The time (s), vertical peak (%) and COP path-length (cm) were measured on both tasks. Additionally, counter (%), different peak (%), symmetry ratio, COP x-range and COP y-range were analyzed on STS, 1st peak (%), 2nd peak (%) of weight were analyzed on gait. Intra-class correlation coefficient (ICC), standard error measurement (SEM) and smallest real difference (SRD) were analyzed for test-retest reliability. Results: ICC of all variables except COP path-length appeared to .676~.946 on STS, and to .723~.901 on gait. SEM and SRD of all variables excepting COP path-length appeared .227~8.886, .033~24.575 on STS. SEM and SRD excepting COP path-length appeared about .019~3.933, .054~11.879 on gait. Conclusion: WBB is not only cheaper than force plate, but also easier to use clinically. WBB is considered as an adequate equipment for measuring changes of weight bearing during balance, STS and gait test which are normally used for functional assessment in patients with neurological problems and elderly. The further study is needed concurrent validity on neurological patients, elderly patients using force plate and WBB.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.313-316
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• 2003

This paper presents stand-alone electric power generator using bridge vibration for charging system of health monitoring sensor unit of bridge structure. In this paper, a novel electric power generator utilizing vertical vibration is proposed, which has minimum effect of armature reaction, and the related mechanical and electrical design equations are obtained and then a pilot electric power generator has been implemented. Moreover, the free oscillation test reveals that diode characteristics of rectifier is dominant factor in charging process. Also, simulation results with the Namhae bridge data showed the validity and effectiveness for stand-alone electric power generation.

• Journal of Industrial Technology
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• v.31 no.A
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• pp.123-128
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• 2011

In this study, procedures, a power performance testing system of Wind Turbine System Research Center of Kangwon National University is introduced. Test prodedures and results are presented on a stand-alone vertical-axis 200W wind turbine manufactured by Geum-Poong Energy Inc.. Power performance test is performed according to IEC standard. The test results are compared with the power performance standard. Also, the effects of normalization and disturbed sectors are considered.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.4
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• pp.2253-2260
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• 2020

Background: Patients with low back pain (LBP) experience misalignments in the center of pressure (COP) and muscle imbalances due to frequent onesided posture adjustments to avoid pain. Objectives: To identify the effects of Squat Exercises with Vertical Whole-Body Vibration on the Center of Pressure and Trunk Muscle Activity. Design: Randomized controlled trial. Methods: Thirty LBP patients with an imbalance in the COP were sampled and randomly assigned to an experimental group of 15 patients who under went an intervention involving squat exercises with vertical WBV and a control group of 15 patients who were treated via a walking intervention. As pretests before the interventions, the subjects' COP was identified by measuring their stability index (ST), and erector spinae, rectus abdominis, transverse abdominis, gluteus medius muscle activity was analyzed by determining the % reference voluntary contraction (%RVC) value using surface electromyography while sit to stand. After four weeks, a post test was conducted to remeasure the same variables using the same methods. Results: Statistically significant differences were found in the ST (P<.01) and trunk muscle (P<.05, P<.001) in the experimental group before and after the intervention. In terms of the differences between the left- and right-side (RL) muscle activity, only the transverse abdominis (TrA) and gluteus medius (GM) exhibited statistically significant increase (P<.05). A comparison of the groups showed statistically significant differences in the TrA with respect to muscle activity (P<.05) and in the RLTrA and RLGM in terms ofthe difference between left- and right-side muscle activity (P<.01). Conclusion: Squat exercises with vertical WBV produced effective changes in the COP of patients with LBP by reducing muscle imbalances through the delivery of a uniform force. In particular, strengthening the TrA and reducing an imbalance in the GM were determined to be important factors in improving the COP.

• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.877-883
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• 2019

Superconducting multi-spoke cavities are outstanding alternative choice for acceleration of heavy ions in medium velocity regimes. Based on the scheme of China ADS, several researches on the superconducting double-spoke cavities were done and two prototype cavities have been developed. In this paper, the RF design, the mechanical design and fabrication considerations of the bare cavity will be described in detail. After Buffered Chemical Polishing and High Pressure Rinsing, one of the prototype cavities was installed into the Vertical Test Stand for high gradient RF testing at 4.2 K. The measurement results of the quality factor as a function of the accelerating field and the maximum surface field will be presented. An accelerating gradient of more than 15 MV/m is achieved during the test, with maximum surface electric field of 58 MV/m, and maximum surface magnetic field of 117 mT.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.643-648
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• 1997

P.C Bearing Plate method, corresponding to the existing steel plate build-up method, is developed by the very first in domestic and is applied to the foundation in the HYUNDAI building at Kang-Nam. P. C Bearing Plate produced in ourself P.C plant can stand against vertical load of 7,000ton obtaining allowable force of soil. It is possible to minmize cost expediting, do site assembling and omit unnecessary excavation work by plant prefabrication of foundation member. The purpose of this paper is to study the optimum mixing design of Ultra-high strength concrete ($\acute{f}_{C91}$= 950kg/$\textrm{cm}^2$), crack control through measuring the heat of hydration, mock up test for the optimum curing method. As mentioned above, developing the Ultra-high strength Precast Concrete Bearing Plate set up successfully in the site foundation work of the HYUNDAI Building at Kang-Nam.

• Fire Science and Engineering
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• v.24 no.6
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• pp.82-88
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• 2010

Major structural elements such as columns and beams are designed to withstand the vertical and horizontal loads. Futhermore, when the structural elements were engulfed with fire the structural stability should be stand without failure. The beams have been developed in aspects of structural stability but an evaluation of fire performance was not done. So the data of fire resistance performance of beams filled with concrete at web on H-section is not known. The purpose of this paper is to analyse the correlation between temperature analysis and fire test with the beams and to show the fire resistance performance with two methods.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.4
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• pp.372-380
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• 1997

This paper describes experimental investigations of helium-air exchange flows through parti¬tioned opening and two-opening. Such exchange flows may occur following rupture accident of stand pipe in high temperature gas cooled reactor. A test vessel with the two types of small open¬ing on top of test cylinder is used for experiments. An estimation method of mass increment is developed and applied to measure the exchange flow rate. A technique of flow visualization by Mach-Zehnder interferometer is provided to recognize the exchange flows. In the case of exchange flow through the partitioned opening, flow passages of upward flow of the helium and downward flow of the air within the opening are separated by vertical partition, and the two flows interact out of entrance and exit of the opening. Therefore, an experiment of the exchange flow through two-opening is made to investigate effect of the fluids interaction of the partitioned opening sys¬tem. As a result of comparison of the exchange flow rates between the two types of the opening system, it is found that the exchange flow rate of the two-opening system is larger than that of the partitioned opening system due to absence of the effect of fluids interaction. Finally, the fluids interaction between the upward and downward flows through the partitioned opening is found to be an important factor on the helium-air exchange flow.