• Title/Summary/Keyword: Moment

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Effects of Combined Wedge on Angle and Moment of Ankle and Knee Joint During Gait in Patients With Genu Varus

  • Yang, Hae Sun;Choi, Houng Sik
    • Journal of International Academy of Physical Therapy Research
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    • v.7 no.2
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    • pp.1025-1030
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    • 2016
  • The purpose of this study was to investigate the effects of combined wedge on the range of motion in ankle and knee joint, ankle eversion moment and knee adduction moment, and center of pressure excursion of foot for genu varus among adult men during gait. This study was carried out with 10 adult men for genu varus in a motion analysis laboratory in J university. The subjects of the experiment were measured above 5cm width between the knees on contact of both medial malleolus of ankle while standing. The width of their knees in neutral position was measured without the inversion or eversion of the subtalar joint by the investigator. The subjects of the experiment were ten who were conducted randomly for standard insole, insole with $10^{\circ}$ lateral on rear foot wedge, insole at $10^{\circ}$lateral on rear foot and $5^{\circ}$ medial on fore foot wedge. Before and after intervention, changes on the range of motion in ankle and knee joint, ankle eversion moment and knee adduction moment, and center of pressure excursion were measured. In order to compare analyses among groups; repeated one-way ANOVA and $Scheff{\acute{e}}$ post hoc test were used. As a result, combined wedge group was significantly decreased compared to control wedge group in terms of knee varus angle in mid-stance(p<.05). Combined wedge group was significantly decreased compared to lateral wedge group in terms of ankle eversion moment in whole stance(p<.05). Combined wedge group was significantly decreased compared to lateral wedge group in terms of knee adduction moment in whole stance(p<.05). Combined wedge group was significantly decreased compared to lateral wedge in terms of center of pressure excursion in whole stance(p<.05). The results of this study suggest that combined wedge for genu varus decreased ankle eversion moment and knee adduction moment upon center of pressure excursion. We hypothesize that combined wedge may also be effective in the protection excessive ankle pronation.

Optimum Yaw Moment Distribution with Electronic Stability Control and Active Rear Steering (자세 제어 장치와 능동 후륜 조향을 이용한 최적 요 모멘트 분배)

  • Yim, Seongjin
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.12
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    • pp.1246-1251
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    • 2014
  • This article presents an optimum yaw moment distribution scheme for a vehicle with electronic stability control (ESC) and active rear steering (ARS). After computing the control yaw moment in the yaw moment controller, it should be distributed into tire forces, generated by ESC and ARS. In this paper, yaw moment distribution is formulated as an optimization problem. New objective function is proposed to tune the relative magnitudes of the tire forces. Weighed pseudo-inverse control allocation (WPCA) is adopted to solve the problem. To check the effectiveness of the proposed scheme, simulation is performed on a vehicle simulation package, CarSim. From the simulation, the proposed optimum yaw moment distribution scheme is shown to effective for vehicle stability control.

A Case Study on the Structural Design Improvement of a Mold M/C's Head Slides for Smooth Motion Regarding to Inertia and Moment Impact (금형가공센터 고속 이송체의 성능 안정화를 위한 설계개선 사례)

  • 최영휴;홍진현;최응영;이재윤;김태형;최원선
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.04a
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    • pp.410-415
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    • 2004
  • Heavy-weight head slides may cause excessive inertia impact & moment on the machine tool structure when they move or stop abruptly during operation. Consequently these inertia impact and unbalanced moment bring transient vibrations and rough sliding motions on the machine structure. Machine tool engineers have tried many kind of feed-slide designs in order to solve this problem; for example, the design optimization of the moving structure for minimum weight and maximum stiffness, box-in-box type slide design, and so on. In this article, force and moment equilibrium equations regarding to the inertia force & moment were derived for each one of a mold M/C's head slides. Furthermore, five different design configurations of head slide assembly were reviewed for its design improvement regarding to force & moment calculations and finite element structural analysis results.

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Uncertainty Evaluation of a multi-axis Force/Moment Sensor

  • Kim, Gab-Soon
    • International Journal of Precision Engineering and Manufacturing
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    • v.3 no.3
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    • pp.5-11
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    • 2002
  • This paper describes the methods for calibration and evaluation of the relative expanded uncertainty of a multi-axis force/moment sensor. In order to use the sensor in the industry, it should be calibrated and its relative expanded uncertainty should be also evaluated. At present, the confidence of the sensor is shown with only interference error. However, it is not accurate, because the calibrated multi-axis force/moment sensor has an interference error as well as a reproducibility error of the sensor, etc. In this paper, the methods fur calibration and for evaluation of the relative expanded uncertainty of a multi-axis force/moment sensor are newly proposed. Also, a six-axis force/moment sensor is calibrated with the proposed calibration method and the relative expanded uncertainty is evaluated using the proposed uncertainty evaluation method and the calibration results. It is thought that the methods fur calibration and evaluation of the uncertainty can be usually used for calibration and evaluation of the uncertainty of the multi-axis force/moment sensor.

Sidesway가 생기는 강구조의 Moment분배법 완전해법

  • Kim, Taek-Sin
    • Korean Architects
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    • no.11 s.82
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    • pp.26-35
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    • 1975
  • The present Structuralists have usually calculated the end Moment of Rigid-frame members by using the Moment Distribution Method, presented by Hardy Cross in 1930, on the Basis of Elastic Law. But this method is considered to be an unfinished solution in case of the moment condition, which the Non-Equilibrium distributed loads or the Horizontal Force acted upon it result in deflection. Hence, after finishing the calculation of stress by means of the Moment Distribution Method, the stress condition due to Horizontal Forces had to be corrected approximatly. However we can directly get the solution of Rigid-frame having sidesway not by above method but by the Moment Distribution computation. Consequently this method is regarded as a Perfect Moment Distribution Method. Here 1 present.

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Modified inverse moment estimation: its principle and applications

  • Gui, Wenhao
    • Communications for Statistical Applications and Methods
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    • v.23 no.6
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    • pp.479-496
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    • 2016
  • In this survey, we present a modified inverse moment estimation of parameters and its applications. We use a specific model to demonstrate its principle and how to apply this method in practice. The estimation of unknown parameters is considered. A necessary and sufficient condition for the existence and uniqueness of maximum-likelihood estimates of the parameters is obtained for the classical maximum likelihood estimation. Inverse moment and modified inverse moment estimators are proposed and their properties are studied. Monte Carlo simulations are conducted to compare the performances of these estimators. As far as the biases and mean squared errors are concerned, modified inverse moment estimator works the best in all cases considered for estimating the unknown parameters. Its performance is followed by inverse moment estimator and maximum likelihood estimator, especially for small sample sizes.

FREE SURFACE FLOW COMPUTATION USING MOMENT-OF-FLUID AND STABILIZED FINITE ELEMENT METHOD (Moment-Of-Fluid (MOF) 방법과 Stabilized Finite Element 방법을 이용한 자유표면유동계산)

  • Ahn, H.T.
    • 한국전산유체공학회:학술대회논문집
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    • 2009.11a
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    • pp.228-230
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    • 2009
  • The moment-of-fluid (MOF) method is a new volume-tracking method that accurately treats evolving material interfaces. Based on the moment data (volume and centroid) for each material, the material interfaces are reconstructed with second-order spatial accuracy in a strictly conservative manner. The MOF method is coupled with a stabilized finite element incompressible Navier-Stokes solver for two fluids, namely water and air. The effectiveness of the MOF method is demonstrated with a free-surface dam-break problem.

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SEXTIC MOMENT PROBLEMS ON 3 PARALLEL LINES

  • Yoo, Seonguk
    • Bulletin of the Korean Mathematical Society
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    • v.54 no.1
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    • pp.299-318
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    • 2017
  • Sextic moment problems with an infinite algebraic variety are still widely open. We study the problem with a single cubic column relation associated to 3 parallel lines in which the variety is infinite. It turns out that this specific column relation has a strong connection with moment problems that have a symmetric algebraic variety. We present more concrete solutions to some sextic moment problems with a symmetric variety.

ESTIMATING THE DOMAIN OF ATTRACTION OF HIV-1 SYSTEM BASED ON MOMENT METHOD

  • LI, CHUNJI;YAO, HAN
    • Journal of applied mathematics & informatics
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    • v.36 no.5_6
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    • pp.349-358
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    • 2018
  • In this article, we discuss the domain of attraction of HIV-1 system by using the moment theory. First, the asymptotic stabilities of the equilibrium point of the system are given, and then we introduce how to use the moment method to estimate domain of attraction. Finally, one simulation shows the effectiveness of moment method.

THE CAYLEY-BACHARACH THEOREM VIA TRUNCATED MOMENT PROBLEMS

  • Yoo, Seonguk
    • Korean Journal of Mathematics
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    • v.29 no.4
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    • pp.741-747
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    • 2021
  • The Cayley-Bacharach theorem says that every cubic curve on an algebraically closed field that passes through a given 8 points must contain a fixed ninth point, counting multiplicities. Ren et al. introduced a concrete formula for the ninth point in terms of the 8 points [4]. We would like to consider a different approach to find the ninth point via the theory of truncated moment problems. Various connections between algebraic geometry and truncated moment problems have been discussed recently; thus, the main result of this note aims to observe an interplay between linear algebra, operator theory, and real algebraic geometry.