• Title/Summary/Keyword: cross-sectional area

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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.

The Evaluation Model of Aggregate Distribution for Lightweight Concrete Using Image Analysis Method (이미지 분석을 이용한 경량골재 콘크리트의 골재분포 판정기법 개발)

  • Ji, Suk-Won
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.10
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    • pp.11-18
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    • 2018
  • In this study, the cross-sectional image has been acquired to evaluate the aggregate distribution affecting quality of lightweight aggregate concrete, and through the binarization method, the study is to calculate the aggregate area of upper and lower sections to develop the method to assess the aggregate distribution of concrete. The acquisition of cross-section image of concrete for the above was available from the cross-sectional photography of cleavage tension of a normal test specimen, and an easily accessible and convenient image analysis software was used for image analysis. As a result, through such image analyses, the proportion of aggregate distribution of upper and lower sections of the test specien could be calculated, and the proportion of aggregate area U/L value of the upper and lower regions of concrete cross-section was calculated, revealing that it could be used as the comprehensive index of aggregate distribution. Moreover, through such method, relatively easy image acquisition methods and analytic methods have been proposed, and this indicated that the development of modeling to assess aggregate distribution quantitatively is available. Based on these methods, it is expected that the extraction of fundamental data to reconsider the connectivity with processes in concrete will be available through quality assessment of quantitative concrete.

COMPARATIVE STUDY ON MORPHOLOGY OF CROSS-SECTION AND CYCLIC FATIGUE TEST WITH DIFFERENT ROTARY NITI FILES AND HANDLING METHODS (수종의 NiTi 전동 파일 단면 형태 비교 및 pecking motion의 사용방법이 피로 파절에 미치는 영향)

  • Kim, Jae-Gwan;Kum, Kee-Yeon;Kim, Eui-Seong
    • Restorative Dentistry and Endodontics
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    • v.31 no.2
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    • pp.96-102
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    • 2006
  • There are various factors affecting the fracture of NiTi rotary files. This study was performed to evaluate the effect of cross sectional area, pecking motion and pecking distance on the cyclic fatigue fracture of different NiTi files. Five different NiTi $files-Profile^{(R)}$ (Maillefer, Ballaigue, Switzerland), $ProTaper^{TM}$(Maillefer, Ballaigue, Switzerland), $K3^{(R)}$ (SybronEndo. Orange, CA) , Hero $642^{(R)}$ (Micro-mega, Besancon, France), Hero $Shaper^{(R)}$ (Micro-mega, Besancon, France)-were used. Each file was embedded in temporary resin, sectioned horizontally and observed with scanning electron microscope. The ratio of cross-sectional area to the circumscribed circle was calculated. Special device was fabricated to simulate the cyclic fatigue fracture of NiTi file in the curved canal,. On this device, NiTi files were rotated (300rpm) with different pecking distances (3 mm or 6 mm) and with different motions (static motion or dynamic pecking motion) . Time until fracture occurs was measured. The results demonstrated that cross-sectional area didn't have any effect on the time of file fracture. Among the files, $Profile^{(R)}$ took the longest time to be fractured. Between the pecking motions, dynamic motion took the longer time to be fractured than static motion. There was no significant difference between the pecking distances with dynamic motion, however with static motion, the longer time was taken at 3mm distance. In this study, we could suggest that dynamic pecking motion would lengthen the time for NiTi file to be fractured from cyclic fatigue.

Effect of Condensation on Spray Characteristics of Simplex Swirl Nozzle (응축이 심플렉스 와류 노즐의 분무 특성에 미치는 영향)

  • Koh, Kwang-Uoong;Lee, Sang-Yong
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.107-112
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    • 2001
  • The effect of ambient gas (steam) condensation on swirl spray characteristics were studied experimentally for low subcooling condition of the liquid. The configuration of the liquid(water) sheet and the breakup modes were examined. Also variation of the discharge coefficient, breakup length, local and the cross-sectional area-averaged SMD of droplets with the liquid flow(injection) rate were obtained. The perforation breakup mode appears dominant with condensation while the aerodynamic wave breakup mode is dominant without condensation(in the air environment). The discharge coefficient, breakup length and the mean drop sizes decrease in a same manner with increasing of the liquid flow rate for both cases(with and without condensation). The condensation effects are insignificant with the discharge coefficient. However, the local and cross-sectional area-averaged SMD are larger and the breakup length becomes shorter in the steam environment. The spray angle predicted from the volumetric flux distribution along the radial direction of the sprays in the steam environment becomes larger with condensation.

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Numerical study of compression waves passing through two-continuous ducts (두 연속 덕트를 전파하는 압축파의 수치해석적 연구)

  • Kim, Hui-Dong;Heo, Nam-Geon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.6
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    • pp.823-831
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    • 1998
  • In order to investigate the impulsive noise at the exit of high-speed railway tunnel and the pressure transients inside the tunnel, numerical calculations using a Total Variation Dimishing difference scheme were applied to axisymmetric unsteady compressible flow field. Some compression wave forms were assumed to model the compression wave produced in real high-speed railway tunnel. The numerical data were extensively explored to analyze the peak over-pressure and maximum pressure gradient in the pressure wavefront. The effect of the distance and cross-sectional area ratio between two-continuous ducts on the characteristics of the pressure waves were investigated. The peak over-pressure inside the second duct decreases for the distance and cross-sectional area ratio between two tunnels to increase. The peak over-pressure and maximum pressure gradient of the pressure wavefront inside the second duct increase as the maximum pressure gradient of initial compression wave increases. The present results were qualitatively well agreed with the results of the previous shock tube experiment.

A Vowel Discrimination of Korean Monophthongs [i, e, a, o, u, ${\omega}$] Using Vocal Tract Magnetic Resonance Image and F1/F2 (성도 자기공명 영상과 음향정보(F1/F2)를 이용한 한국어 단모음 [이, 에, 아, 오, 우, 으] 판별)

  • Seong, Cheol-Jae;Park, Jong-Won;Kim, Gui-Ryong
    • MALSORI
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    • no.56
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    • pp.103-125
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    • 2005
  • We present a new method of measuring the volume and cross-sectional area of the vocal tract from magnetic resonance images. The vocal tract was divided by the 2 constriction points on the horizontal and vertical planes. The ratios of the volumes of the segment vocal tracts to that of the entire vocal tract play a crucial role in discriminating Korean monophthongs in that vowels were successfully discriminated by the ratios. The discriminant analysis also demonstrated that the acoustic parameters F1 and F2, in addition to the segment volumes, serve as significant parameters in discriminating Korean monophthongs.

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Numerical Analysis of Fully Developed Turbulent Recirculating Flow and Heat Transfer for The Periodic Variations of Cross Sectional Area (周期的으로 斷面이 變化하는 完全確立된 亂流再循環 流動과 亂流熱傳達의 數値分析)

  • 이병곤;최영돈
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.10 no.1
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    • pp.138-149
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    • 1986
  • A numerical method is developed for the solution of fully developed turbulent recirculating flow whose cross-sectional area varies periodically. This enalbes the flow field analysis to be confined to a single isolated module, without involvement with the entrance region problem. This method are applied to the analysis of the turbulent flow field and heat transfer in artificially roughened annulus with repeated square rib.

Impedance Analysis and Experimental Study of a Solenoid Eddy Current Sensor to Detect the Cross-sectional Area of Non-ferromagnetic Stranded Conductors (비자성 연선도체의 단면적을 검출하기 위한 솔레노이드 와전류 센서의 임피던스 해석 및 실험적 연구)

  • Kim, S.D.;Shim, J.M.
    • Journal of Sensor Science and Technology
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    • v.6 no.2
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    • pp.87-94
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    • 1997
  • Impedance analysis of a Solenoid sensor to detect the cross-sectional area of non-ferromagnetic stranded conductors is described in this paper. To inspect electromagnetic characteristics of conductive materials, a nondestructive test eddy current sensor with an encircling coil is chosen. As solving Maxwell equation, normalized impedance response of the sensor within a conducting rod is modeled and the results are expanded to the stranded wires. Geometrical property affecting on stranded structure is considered and a numerical and experimental study is also presented.

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유한요소법을 이용한 전방압출공정의 내부결함에 관한 연구

  • 김태형;김병민;강범수;최재한
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1992.04a
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    • pp.79-83
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    • 1992
  • According to the variation of hydrostatic pressure on the central axis of deformable material, the V-shaped central bursting defect may be created on extrusion or drawing processes. The process factors whichaffect the generation of defects are die semi-angle, reduction ratio of cross-sectional area, friction factor, material properties and so on. The combination of these factors can determine the prossibility of defect creation and the shape of various round holes which have been created inside already. By the rigid plastic finite element method, this paper describes the observations of change in shape of a round hole with process conditions suchas die semi-angle, reduction ratio of cross-sectional area and friction factorat the unsteady state of axi-symmetrical extrusion process when the round hole is alreadyexisted inside the original billet, and also, the effects of process factors are investigated to prevent the possible defects.

AC Resistance(Rac) comparison between the new type of coil structure and the annular copper coil to maximize the conductor occupying ratio (고정자 권선 점적율을 극대화 하는 새로운 코일구조와 환형동선 코일구조간의 AC Resistance(Rac) 비교)

  • LEE, Eui-Chun;Kim, Yong-Hoon;LEE, Kang-Won;Lee, Su-Woong;Kwon, Soon-O
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.784-785
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    • 2015
  • This paper proposes a new structure of coil to maximize the conductor occupting ratio(conductor cross sectional area than the cross sectional area inside the slot) of the magnetic core. Further, assuming a case in which the 3-D coil is applied to a real motor. Analyze the current density distribution of the coil conductor by electromagnetic analysis method. Finally the AC resistance was measured according to the frequency of the coils. This expereiment is to calculate a optimal operating frequency to obtain high efficiency operational frequency range of motor.

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