• Title/Summary/Keyword: Parameters effects

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The Immediate Effects of Elastic Taping on Center of Pressure and Foot Pressure Distribution

  • Jung-Hee Kim;Jong-Ho Kook;Sang-Mi Lee;Eun-Bin Ko;Song-Yi Han;Yeon-Jeong Kim;Byeong-Jun Min
    • PNF and Movement
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    • v.22 no.1
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    • pp.23-30
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    • 2024
  • Purpose: Ankle instability is a common issue in both daily activities and sports, often leading to recurrent injuries. Elastic taping is a non-pharmacological intervention used to improve ankle stability. This study aimed to investigate the immediate effects of elastic taping on ankle stability, center of pressure (COP) movement, and foot pressure distribution. Methods: A single-group pre-posttest design was employed, with 30 participants included in the study. Plantar pressure and COP parameters were measured before and after the application of elastic taping. Taping was administered in three distinct patterns to enhance ankle stability. Results: Immediate effects of elastic taping were evident in COP parameters. Following taping application, there was a significant decrease in COP total displacement, COP area, and COP velocity. However, no significant changes were observed in plantar pressure parameters. Conclusion: The application of elastic taping in this study demonstrated immediate effects on ankle stability and COP parameters, indicating its potential as a viable intervention for improving balance. Further research with larger sample sizes and long-term follow-up is needed to elucidate the sustained effects of elastic taping on ankle stability.

The effects of uncertainties in structural analysis

  • Pellissetti, M.F.;SchueIler, G.I.
    • Structural Engineering and Mechanics
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    • v.25 no.3
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    • pp.311-330
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    • 2007
  • Model-based predictions of structural behavior are negatively affected by uncertainties of various type and in various stages of the structural analysis. The present paper focusses on dynamic analysis and addresses the effects of uncertainties concerning material and geometric parameters, mainly in the context of modal analysis of large-scale structures. Given the large number of uncertain parameters arising in this case, highly scalable simulation-based methods are adopted, which can deal with possibly thousands of uncertain parameters. In order to solve the reliability problem, i.e., the estimation of very small exceedance probabilities, an advanced simulation method called Line Sampling is used. In combination with an efficient algorithm for the estimation of the most important uncertain parameters, the method provides good estimates of the failure probability and enables one to quantify the error in the estimate. Another aspect here considered is the uncertainty quantification for closely-spaced eigenfrequencies. The solution here adopted represents each eigenfrequency as a weighted superposition of the full set of eigenfrequencies. In a case study performed with the FE model of a satellite it is shown that the effects of uncertain parameters can be very different in magnitude, depending on the considered response quantity. In particular, the uncertainty in the quantities of interest (eigenfrequencies) turns out to be mainly caused by very few of the uncertain parameters, which results in sharp estimates of the failure probabilities at low computational cost.

Accurate parameter extraction method for FD-SOI MOSFETs RF small-signal model including non-quasi-static effects (NQS효과를 고려한 FD-SOI MOSFET의 고주파 소신호 모델변수 추출방법)

  • Kim, Gue-Chol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.10
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    • pp.1910-1915
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    • 2007
  • An accurate and simple method to extract equivalent circuit parameters of fully-depleted silicon-on-insulator MOSFETs small-signal modeling operating at RF frequencies including the non-quasi static effects is presented in this article. The advantage of this method is that a unique and physically meaningful set of intrinsic equivalent circuit parameters is extracted by de-embedding procedure of extrinsic elements such as parasitic capacitances and resistances of MOSFETs from measured S-parameters using simple Z- and Y- matrices calculations. The calculated small-signal parameters using the presented extraction method give modeled Y-parameters which are in good agreement with the measured Y-parameters from 0.5 to 20GHz.

Effect of length scale parameters on transversely isotropic thermoelastic medium using new modified couple stress theory

  • Lata, Parveen;Kaur, Harpreet
    • Structural Engineering and Mechanics
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    • v.76 no.1
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    • pp.17-26
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    • 2020
  • The objective of this paper is to study the deformation in transversely isotropic thermoelastic solid using new modified couple stress theory subjected to ramp-type thermal source and without energy dissipation. This theory contains three material length scale parameters which can determine the size effects. The couple stress constitutive relationships are introduced for transversely isotropic thermoelastic solid, in which the curvature (rotation gradient) tensor is asymmetric and the couple stress moment tensor is symmetric. Laplace and Fourier transform technique is applied to obtain the solutions of the governing equations. The displacement components, stress components, temperature change and couple stress are obtained in the transformed domain. A numerical inversion technique has been used to obtain the solutions in the physical domain. The effects of length scale parameters are depicted graphically on the resulted quantities. Numerical results show that the proposed model can capture the scale effects of microstructures.

Free vibration analysis of plates resting on elastic foundations using modified Vlasov model

  • Ayvaz, Yusuf;Oguzhan, Celal Burak
    • Structural Engineering and Mechanics
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    • v.28 no.6
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    • pp.635-658
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    • 2008
  • An application is presented of a modified Vlasov model to the free vibration analysis of plates resting on elastic foundations. The effects of the subsoil depth, the ratio of the plate dimensions, the ratio of the subsoil depth to the plate dimension in the longer direction, and the value of the vertical deformation parameter within the subsoil on the frequency parameters of plates on an elastic foundation are investigated. This analysis has been caried out by the aid of a computer program. The first ten frequency parameters are presented in tabular and the graphical forms to evaluate the effects of the parameters considered in this study. Then mode shapes corresponding to the first six of the frequency parameters are given in graphs. It is concluded that the effect of the subsoil depth on the frequency parameters of the plates on an elastic foundation is generally larger than those of the other parameters considered in this study.

Effects of the Welding Parameters on the Weld Shape in Nd:YAG Laser Welding of STS 304L (STS 304L의 Nd:YAG 레이저 용접에서 용접조건이 용접부 형상에 미치는 영향)

  • 이형근;석한길;한현수;박울재;홍순복
    • Journal of Welding and Joining
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    • v.22 no.1
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    • pp.58-64
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    • 2004
  • The control of the weld bead shape is important in laser welding of the small parts. The effects of laser welding parameters on the weld bead shape in the pulsed Nd:YAG laser welding of STS 304L material were investigated. Shielding gas type, flow rate, pumping voltage, pulse frequency, pulse width, focal position and overlap distance were selected as laser welding parameters. Experiments were designed and conducted using the Taguchi method which was a statistical experimental method. The weld bead width, penetration, area and aspect ratio were measured and analysed as the weld bead shape properties and the welding parameters were optimized to maximize the weld aspect ratio. Weld aspect ratio were greatly affected by the pulse width, pumping voltage and pulse frequency, and somewhat by the overlap distance, and little by the shielding gas type, flow rate and focal position. A confirmation experiment were conducted using the optimized welding parameters.

Estimation of Genetic Parameters for Direct, Maternal and Grandmatemal Genetic Effects for Birth, Weaning and Six Month Weights of Hanwoo (Korean Cattle)

  • Choi, S.B.;Lee, J.W.;Kim, N.S.;Na, S.H.;Keown, J.F.;Van Vleck, L.D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.2
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    • pp.149-154
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    • 2000
  • The objectives of this study of Hanwoo (Korean Cattle) were 1) to estimate genetic parameters for direct and maternal genetic effects for birth weight, weaning weight, and six months weight which can be used for genetic evaluations and 2) to compare models with and without grandmatemal effects. Data were obtained from the National Livestock Research Institute in Rural Development Administration (RDA) of Korea and were used to estimate genetic parameters for birth weight (BW, n=10,889), weaning weight at 120-d (WW, n=8,637), and six month weight (W6, n=8,478) in Hanwoo. Total number of animals in pedigrees was 14,949. A single-trait animal model was initially used to obtain starting values for multiple-trait animal models. Estimates of genetic parameters were obtained with MTDFREML using animal models and derivative-free REML (Boldman et al., 1995). Estimates of direct heritability for BW, WW, and W6 analyzed as single-traits were 0.09, 0.03, and 0.02 from Model 3 which included direct and maternal genetic, maternal permanental environmental effects, and effects due to sire ${\times}$ region ${\times}$ year-season interaction, respectively. Ignoring sire ${\times}$ region ${\times}$ year-season interaction effect in the model (Model 2) resulted in larger estimates for direct heritability than for Model 3. Estimates of maternal heritability for BW, WW and W6 were 0.04, 0.05, and 0.07 from Model 3, respectively. The estimates of direct-maternal genetic correlation were positive for BW, WW, and W6 with Model 3 but were negative with Model 2 for WW and W6. Estimates of direct genetic correlations between BW and WW, BW and W6, and WW and W6 were large: 0.52, 0.45, and 0.90, respectively. Genetic correlations were also large and positive for maternal effects for BW with maternal effects for WW and W6 (0.69 and 0.74), and even larger for WW with W6 (0.97). The log likelihood values were the same for models including grandmatemal effects as for models including maternal effects for all traits. These results indicate that grandmatemal effects are not important for these traits for Hanwoo or that the data structure was not adequate for estimating parameters for a grandmatemal model.

Effects of Design Parameters of Lug on Tractive Efficiency and Rolling Resistance of Pneumatic Tires (러그의 설계인자(設計因子)가 공기(空氣)타이어의 견인효율(牽引効率) 및 구름저항(抵抗)에 미치는 영향(影響))

  • Chung, Woo Won;Kim, Kyeong Uk
    • Journal of Biosystems Engineering
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    • v.10 no.2
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    • pp.12-18
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    • 1985
  • In order to investigate the effects of design parameters of lug on the tractive performance of pneumatic tires, soil bin tests were conducted for the test tires having different values of design parameters. The experimental results were presented in terms of lug space, lug angle and lug shape versus the tractive efficiency and rolling resistance of the test tires.

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Effects of Process Parameters on the Wear Behavior of Thermally Sprayed Ni-based Hard Coatings (니켈기 경질 용사코팅의 마모거동에 미치는 공정조건의 영향)

  • Kim, Kyun-Tak;Kim, Yeong-Sik
    • Tribology and Lubricants
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    • v.26 no.3
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    • pp.157-161
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    • 2010
  • This study investigated the effects of spray parameters on wear behavior of the Ni-based hard coatings fabricated by thermal spray process. The experiment was designed by an orthogonal array, the Ni-based hard coatings were fabricated according to this experimental design. The wear test was performed on these coatings using ball-on-disk wear tester. The ANOVA was used to analyze the effects of spray parameters on the wear rate of these coatings, as a result, oxygen gas flow and acetylene gas flow were determined as main factors effected on the wear rate. The effects of these two factors on wear behavior were observed by using SEM and EDX.

The Effects of Cell Sizes on Compression and Bending Strength of Aluminum Material (알루미늄 소재의 미세 기공 크기가 압축 및 굽힘 강도에 미치는 영향)

  • 전용필;강충길
    • Transactions of Materials Processing
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    • v.11 no.8
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    • pp.701-709
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    • 2002
  • Aluminium foam material is highly porous material, which has the complicated cellular structure defined by randomly distributed pores in metallic matrix. This structure gives the characteristic properties which cannot be achieved by any other conventional processes. As the properties of aluminium foam material significantly depend on its porosity, a desired profile of properties can be tailored by changing the foam density. But various defects lead to undesirable effects on the mechanical properties. Mechanical properties are dependent on cell sizes and aspect ratios. Therefore, this paper presents the effects of various processing parameters of various parameters on the mechanical properties. For the sake of this, combined stirring was used to fabricate aluminum foam materials by the parameters. Compression and bending tests were performed to investigate the effects of cell sizes and aspect ratios on the mechanical properties.