• Title/Summary/Keyword: Non-Contact Test

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The Comparision of the Static Balance, Contact Area, and Plantar Pressure of Flexible Flat Foot According to Elastic Taping

  • Hyeon-Seong Joo;Sam-Ho Park;Myung-Mo Lee
    • Physical Therapy Rehabilitation Science
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    • v.11 no.4
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    • pp.421-429
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    • 2022
  • Objective: The purpose of this study was to compare and analyze the effects of arch support taping on static balance, static/dynamic foot contact area, and ground reaction force during walking according to the types of elastic tapes with mechanical elasticity differences. Design: Cross-sectional study Methods: Twenty-six participants selected for flexible flat feet through the navicular drop test were randomly assigned to non-taping, Dynamic-taping, and Mechano-taping conditions. Static balance and foot contact area were compared in the standing posture according to arch support taping conditions, and foot contact area and ground reaction force were compared during walking. Results: There was no significant difference in static balance according to the taping condition in the standing position, but the foot contact area in the Mechano-taping condition showed a significant decrease compared to the non-taping condition (p<0.05). The foot contact area during walking significantly decreased in the Dynamic-taping and Mechano-taping conditions (p<0.05), but there was no significant difference between the ground reaction force. Conclusions: Based on the results of this study, it was confirmed that among the types of elastic taping, arch support taping using dynamic taping and Mechano-taping has the effect of supporting the arch with high elastic recovery. Any type of elastic tape can be used for arch alignment in flexible flat foot.

A Study of Non-destructive Indentation and Small Punch Tests for Monitoring Materials Reliability (소재의 안전전단을 위한 비파괴 압입 및 소형펀치 시험법 연구)

  • Ok Myoung-Ryul;Ju Jang-Bog;Lee Jeong-Hwan;Ahn Jeong-Hoon;Nahm Seung Hoon;Lee Hae-Moo;Kwon Dongil
    • 한국가스학회:학술대회논문집
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    • 1997.09a
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    • pp.78-85
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    • 1997
  • Indentation and small punch tests are very powerful methods to monitor the materials reliability since they are very simple, easy and almost non-destructive. First, recently-developed continuous indentation test can provide the more material properties such as hardness, elastic modulus, yield strength, work-hardening exponent, etc., than the conventional hardness test. In our study, the true stress-strain curve was derived from the indentation load-depth curve for spherical indentation. In detail, the strain was able to be obtained from plastic depth/contact radius ratio, and the flow stress was from mean contact pressure through the analysis of elastic-plastic indentation stress field. Secondly, the small punch test was studied to evaluate the fracture toughness and defomation properties such as elastic modulus and yield strength. Like the indentation test, this test can be applied without severe damage of the target structure.

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Development of a Rotational Torque Calibration System (회전 토크 교정장치 개발에 관한 연구)

  • 김갑순;권영하
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.10
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    • pp.2646-2653
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    • 1993
  • A rotational torque calibration system is developed to measure rotational torque of power generating systems and to calibrate non-contact rotational torque measurement systems. The maximum capacity of the developed system is 4.5 N-m. It is composed of a DC motor, a DC generator, a control system, a master torque cell, a slip ling/brush set, supporters, a bed etc. The control system is characterized by the closed-loop control with differential intergrator. Rotational torque measurement test and unit response test are conducted to estimate the accuracy of the developed system. It is found that system maintain high consistency and accuracy with the maximum error of 0.25%, Therefore the developed system can be used to measure the rotational torque of power generating systems and to calibrate non-contact rotational torque measurement systems.

Formability of Non-Vinyl Pre-coated Metal Sheet (Non-Vinyl Pre-coated Metal재의 성형성에 관한 연구)

  • Kim, Dong-Hwan;Kim, Byung-Min
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.4
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    • pp.121-128
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    • 2001
  • This study has been performed to investigate formability of non-vinyl PCM(pre-coated metal)sheet. First, physical test of PCM sheets were tested to evaluate finish coating characteristic of PCM. And then, test equipment was made for friction test and three non-vinyl PCM sheets were tested by straight pulling method. This paper provides the results of the friction tests showing the influence of sheet surface texture and process conditions. It was found that the influence of contact pressure and speed had an effect upon the level of friction. Also using tests, the scratch resistance of a series of polyester coating has been investigated. This investigation aims to clarify the process conditions that prevent the scratch of PCM to form the good electrical appliances such as microwave oven, air conditioner and refrigerator etc.

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A Study on the Attenuation of Flip-over Vibration in the Flat Blade Windshield Wiper (플랫 블레이드 윈드실드 와이퍼의 역전 진동 저감에 관한 연구)

  • Lee, Hyeong-Ill
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.10
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    • pp.974-984
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    • 2012
  • This research introduces a new method to attenuate flip-over vibration generation in the flat blade windshield wiper by adjusting the contact pressure between the windshield glass and the blade. The knocking force in the flip-over action of the blade is decreased by inducing gradual tilting-over along the rubber strip of the blade. This gradual tilting-over is induced by introducing a non-uniform contact pressure distribution between the blade and windshield glass. The contact pressure distribution is adjusted by controlling the unloaded profile of the body spring in the blade using a procedure proposed in a previous study. Two blades, one blade designed to generate a uniform pressure distribution and the other designed to generate non-uniform pressure distribution, are developed using the procedure. Contact pressure distributions of the developed blades are measured using a special device and compared with the intended distributions confirming the similarities between the two groups. Vertical and lateral vibrations of the two blades are measured under realistic operating condition simulated by a wiper test rig. The vertical vibrations of the blade with non-uniform contact pressure are substantially smaller than corresponding vibrations of the blade with uniform contact pressure over the entire rubber strip.

A Study on Third Body Abrasion in the Small Clearance Region Adjacent to the Contact Area

  • Kim, Hyung-Kyu;Lee, Young-Ho;Heo, Sung-Pil;Jung, Youn-Ho
    • KSTLE International Journal
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    • v.4 no.1
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    • pp.8-13
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    • 2003
  • Abrasion in fretting wear mechanism is studied experimentally with the specimens of two different shapes of spacer grid spring and fuel tubes of a nuclear fuel. Reciprocating sliding wear test has been carried out in the environment of air and water at room temperature. Especially, third body abrasion is referred to for explaining the wear region expansion found during the slip displacement increase with constant normal contact farce. It is found that the expansion behaviour depends on the contact shape. The small clearance between the tube and spring seems to be the preferable region of the wear particle accumulation, which causes third body abrasion of the non-contact area. Even in water environment the third body abrasion occurs apparently. Since the abrasion on the clearance contributes wear volume, the influence of the contact shape on the severity of third body abrasion should be considered to improve the grid spring design in the point of restraining wear damage of a nuclear fuel.

Latest Technology of Non Destructive Inspection for Welded Structure (용접구조물의 최신 비파괴 검사기술)

  • Kim, Youngsik;Kil, Sangcheol
    • Journal of Welding and Joining
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    • v.35 no.2
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    • pp.63-70
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    • 2017
  • As the Non Destructive Test (NDT) for the welded structure, PT(Penetration Test). MT(Magnetic Test), RT (Radioisotope Test) and UT(Ultrasonic Test) methods are widely used in practice. These NDT methods have been developed toward high efficiency, low cost, real time, and high precise new NDT. For example, RT methods are developed to CT(Computed Tomography)and DR(Digital Radiography), and UT metheds are developed into Phased array, Guide wave, TOFD method. Moreover, the Infrared thermography and Laser ultrasonic technique are newly developed for applying in high temperature objects as the non-contact NDT methods. In this review paper the new high efficiency NDT methods for the welded structure are introduced and the trend of NDT rules applying in welded structure are described.

Effects of Non-Contact Complex Exercise Program on the Older over 65 Years of Age on Muscle Strength, Falling Efficacy and Balance Ability

  • Sam Ho Park;Youn Jung Oh;Myung Mo Lee
    • Physical Therapy Rehabilitation Science
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    • v.12 no.2
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    • pp.167-176
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    • 2023
  • Objective: The purpose of this study was to investigate the effects of anon-contact complex exercise program on muscle strength, fall efficacy, quality of life, and balance ability in older over 65 years of age. Design: A randomized controlled trial Methods: A total of 37 people in older over 65 years of age participated in the study. Random program was conducted and assigned to the experimental group (n=19) and the control group (n=18). Both groups performed the older people welfare center program. In addition, in the experimental group, a non-contact complex exercise program for muscle and balance exercise was performed. All interventions were performed 2 times a week, for a total of 6 weeks. chair stand test (CST), fall efficacy scale (FES), Euro quality of life 5 dimension (EQ-5D), Berg balance scale (BBS), timed up and go test (TUG), Fullerton advanced balance scale (FAB) were measured before and after the intervention to compare their effectiveness. Results: Both groups showed significant differences in CST, FES, EQ-5D, BBS, and TUG before and after intervention (p<0.05). FAB showed significant differences before and after intervention in all items except for FAB 8 and 9 items in the experimental group. In addition, the experimental group showed significant differences in CST, FES, BBS, TUG, FAB (except 1, 7, 8, 9) compared to the control group (p<0.05). Conclusions: The non-contact complex exercise program is an effective intervention method that has clinical significance in improving muscle strength, fall efficacy and static and dynamic balance abilities for the older over 65 years of age.

Development of a Technique for Detection of Contact Wire Wear using High-Speed Camera (고속카메라를 이용한 전차선 마모 검측 영상처리 알고리즘 개발)

  • Park, Young;Cho, Yong-Hyeon;Cho, Chul-Jin;Kim, Won-Ha
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.8
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    • pp.632-637
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    • 2010
  • The measurement of contact wire wear in electric railways is one of the key test parameters to increase speed and maintain safety in electric railways. Wear caused by continuous interaction between pantographs and contact wires has a negative effect on current collection quality and severely damaged contact wires might cause hazardous accidents. This paper introduces a non-contact optical-based contact wire wear measuring system that will replace conventional wear detecting methods conducted by maintenance vehicles or workers. The system is implemented by high-speed cameras that can collect images of contact wires during vehicle operation, a laser used to create images profile of the contact wire surface, and a computer used to process the collected images. The proposed system is designed to assist maintenance of overhead contact lines by creating geometrically plotted images of contact wires to detect contact wire wear during operation on conventional lines or high-speed lines.

Fatigue Life Evaluation for Railway Turnout Crossing using the Field Test (현장측정을 통한 분기기 망간 크로싱의 피로수명 평가)

  • Um, Ju-Hwan;Choi, Jung-Youl;Park, Yong-Gul
    • Journal of the Korean Society for Railway
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    • v.9 no.2 s.33
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    • pp.169-173
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    • 2006
  • The major objective of this study is to investigate the fatigue life evaluation of immovability crossing for railway turnout by the field test. In railway engineering, an appliance is necessary to allow a vehicle to move from one track to another. This appliance came to be known technically as turnout. So, turnout is required very complex railway technologies such as rolling stock, track. Due to the plan under the application of high speed train, turnout are needed more stable far fatigue behaviors. It analyzed the mechanical behaviors of turnout crossing with propose its advanced technical type on the field test and fatigue evaluation far the dynamic fatigue characteristics. As a result, the advanced type crossing are obviously effective for the fatigue damage ratio and dynamic response which is non-modified type. The analytical and experimental study are carried out to investigate the passing path of contact surface and fatigue damage trend decrease dynamic stresses and deflections on advanced crossing type, And the advanced type reduce dynamic fatigue damage ratio and increase fatigue life(about each 38%) more than non-modified type. From the field test results of the servicing turnout crossing, it is evaluated that the modification of contact angle, weight, material and sectional properties is very effective fur ensure against fatigue risks.