• Korean Journal of Applied Biomechanics
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• v.31 no.2
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• pp.104-112
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• 2021

Objective: This study aimed to analyze the effects of consecutive whole body vibration through heel raise posture on the center of pressure and electromyography of anterior tibial muscle, lateral gastrocnemius and soleus muscles during single-leg stance. Method: The subjects of this study included 30 healthy males in their 20's, with the following inclusion criteria: no history of orthopaedic medical history, no participation in regular exercises, no history of whole body vibration exercise, and right leg being the dominant leg. The experimental procedure involved pretreatment measurement of eye open single-leg stance, application of whole body vibration for 30 seconds, post-treatment measurement (3 measurements in total). Static and dynamic movements have been measured over 2 separate experiments, with 72 hours gap between the experiments. Static movement involved maintaining single-leg heel raise posture for 30 seconds while applying whole body vibration, and dynamic movement involved heel raise (15 repetitions over 30 seconds) while applying whole body vibration. The strength of applied whole body vibration was 35 Hz frequency and 2~4 mm amplitude. Results: As the single-leg posture after static heel raise posture, mediolateral velocity of the center of pressure at post 2 and post 3 were significantly reduced compared to the pre-treatment measurement. In addition, the percentage for reference voluntary contraction in anterior tibial muscle and soleus and median frequency at anterior tibial muscle and lateral gastrocnemius muscle at post 3 were significantly decreased compared to the pre-treatment value. As the single-leg posture after dynamic heel raise posture, the mediolateral 95% edge frequency of the center of pressure and median frequency at anterior tibial muscle, lateral gastrocnemius muscle, and soleus muscle at post 3 were significantly reduced compared to the pre-treatment value. Conclusion: Acute whole body vibration via static and dynamic heel raise posture have positive effect on mediolateral posture control during single-leg stance.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.6
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• pp.55-63
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• 1999

The acceleration of the performance of machine tools influences the development of the semi-conductor and optical technology as the development of NC and measurement technology. Because the measurement has been done to unload condition without considering of mechanical stiffness in the case of machining center as we measure the quasi-static error of machine tools on general study people who works on the spot has many problems on the data value. Also there are no satisfiable results until now in spite of many studys about this because the deflections of the table and the shaft supporting a workpiece influence, influence the accuracy of the table and shaft supporting a workpiece influence the accuracy of the workpiece. And there is doubt about the inspection method of measured error. In this paper Therefor we will help working more accurately on the spot by measuring analyzing displaying the defoec-tion of the table and support shaft when we load on the table and the support shaft of machining center using laser interfer-ometer. Also we try to settle new conception of the measurement method and more accurate grasp of the deflection tenden-cy by verifing the tendency of the error measured through the comparison of the simulated error measured through the comparison of the simulated error using ANSYS a common finite element analysis program which is able to measure heat deformation material deformation and error resulted from this study.

• Computers and Concrete
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• v.15 no.5
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• pp.771-794
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• 2015

This paper proposes an innovative method for selection of measurement sets in static parameter identification of concrete or steel bridges. This method is proved as a systematic tool to address the first steps of Structural System Identification procedures by observability techniques: the selection of adequate measurement sets. The observability trees show graphically how the unknown estimates are successively calculated throughout the recursive process of the observability analysis. The observability trees can be proved as an intuitive and powerful tool for measurement selection in beam bridges that can also be applied in complex structures, such as cable-stayed bridges. Nevertheless, in these structures, the strong link among structural parameters advises to assume a set of simplifications to increase the tree intuitiveness. In addition, a set of guidelines are provided to facilitate the representation of the observability trees in this kind of structures. These guidelines are applied in bridges of growing complexity to explain how the characteristics of the geometry of the structure (e.g. deck inclination, type of pylon-deck connection, or the existence of stay cables) affect the observability trees. The importance of the observability trees is justified by a statistical analysis of measurement sets randomly selected. This study shows that, in the analyzed structure, the probability of selecting an adequate measurement set with a minimum number of measurements at random is practically negligible. Furthermore, even bigger measurement sets might not provide adequate SSI of the unknown parameters. Finally, to show the potential of the observability trees, a large-scale concrete cable-stayed bridge is also analyzed. The comparison with the number of measurements required in the literature shows again the advantages of using the proposed method.

• Journal of Auto-vehicle Safety Association
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• v.13 no.4
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• pp.14-19
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• 2021

This paper presents LiDAR static obstacle map based vehicle dynamic state estimation algorithm for urban autonomous driving. In an autonomous driving, state estimation of host vehicle is important for accurate prediction of ego motion and perceived object. Therefore, in a situation in which noise exists in the control input of the vehicle, state estimation using sensor such as LiDAR and vision is required. However, it is difficult to obtain a measurement for the vehicle state because the recognition sensor of autonomous vehicle perceives including a dynamic object. The proposed algorithm consists of two parts. First, a Bayesian rule-based static obstacle map is constructed using continuous LiDAR point cloud input. Second, vehicle odometry during the time interval is calculated by matching the static obstacle map using Normal Distribution Transformation (NDT) method. And the velocity and yaw rate of vehicle are estimated based on the Extended Kalman Filter (EKF) using vehicle odometry as measurement. The proposed algorithm is implemented in the Linux Robot Operating System (ROS) environment, and is verified with data obtained from actual driving on urban roads. The test results show a more robust and accurate dynamic state estimation result when there is a bias in the chassis IMU sensor.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.488-492
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• 2022

Objective: The purpose of this study is to find out the reliability and validity of the newly updated Balancia 2.5 program using Wii balance board through equipment that can measure center of pressure data with the precision. Design: Cross-sectional study Methods: Twenty-seven healthy adults participated in the study. The subjects were assessed for static balance ability by Accusway, and were assessed for static balance ability on Wii balance board connected to theBalancia 2.5 program.To limit postural fluctuations due to stare, the subjects were asked to look at a 15 cm dot drawn 3 m in front of them for 30 seconds with their eyes open. Static balance ability data such as path length and sway velocity were extracted from all measurement tools.Intra-rater and inter-rater reliability and validity were extracted through intraclass correlation coefficient (ICC) and 95% confidence interval (CI). Results: The intra-rater reliability that the same rater shows consistent results through test-retest was a high level at ICC=0.968 (0.926~0.986), and inter-rater reliability that the requires consistent results even when measured by different raters was a high level at ICC=0.943 (0.870~0.975). The validity was a high level at ICC=0.948 (0.881~0.977), which shows whether the measurement tool is properly measuring what it is intended to measure. Conclusions: The Balancia 2.5 program, newly updated through this study, proved to be a program with high reliability and validity in evaluating static balance ability like the existingBalancia 2.0 program.

• The Journal of Korean Physical Therapy
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• v.16 no.2
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• pp.116-127
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• 2004

The purpose of this study was to determine the effect of shoe lift of the affected limb in subjects with hemiplegia. The subjects of this study were 18 post-stroke hemiplegics. For the study, insole of the paretic side was lifted 10 mm higher, and static weight bearing was measured before and after the lift application. For the measurement of carry-over effect of lift, we got data of those three items prior to and 3 weeks after lift application and 3 days after removal of the lift. Static weight bearing was significantly increased both just after and continuous application of lift for 3 weeks than before. According to this study, lift applied to the shoe of the paretic limb was effective in inducing static weight bearing in the paretic limb. This study suggests that symmetry, induced by shoe lift applied to the paretic limb, could help correct abnormal posture that would be caused in standing and prevent development of abnormal muscle tone in subjects with hemiplegia caused by unilateral stroke.

• Transactions of Materials Processing
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• v.10 no.1
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• pp.42-52
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• 2001

The static softening mechanisms of 304 stainless steel were studied by hot torsion test. The interrupted deformation tests were performed In the range of 900~$1100^{\circ}C$ and 5.0$\times$$10^{-2}$- 5.0$\times$$10^0$/sec. The metadynamic recrystallization (MDRX) could be distinguished from the static recrystallization (SRX). Comparison of the softening kinetics between MDRX and SRX showed that the rate of MDRX was more rapid than that of SRX for the same deformation variables. To the exact prediction of MDRX, the MDRX parameter, which could be simultaneously estimated by the interpass time and Zener-Hollomon parameter, was developed. The time lot 50% MDRX, $t_{0.5} was modeled using the deformation parameters : $t_{0.5} = 1.33\times10^{-11}$ $\.\varepsilon^{-0.41}$ D exp(230.3kJ/mol/RT) and the predicted value was very correspondent with the measurement. It was found that the static parameters such as interpass time can control the dynamic states in the several successive deformation process.

• Proceedings of the ESK Conference
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• 1995.04a
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• pp.62-71
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• 1995

This paper measured the range of arm joint motion for Korean 54 male in twenties. The subjects are measured directly using Goniometer and angle gauge. The static measurement variables are seven and the dynamic measurement variables are thirteen. The anthropometric datum are analyzed by basic statistical analysis, correlation analysis and regression analysis using commercial SAS program. The results of analysis are compared with American students anthropometric data by Laubach, 1978.

• 한국가스학회:학술대회논문집
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• 1999.09a
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• pp.100-107
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• 1999

• Journal of the Korean Society for Precision Engineering
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• v.31 no.5
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• pp.423-430
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• 2014

In this study, the five-DOF motion at ultra-precision linear stage under static and dynamic conditions are evaluated through the extending application of ISO 230-2. As the performance factors, the bi-directional accuracy and repeatability of the five-DOF motion are quantitatively evaluated with the measurement uncertainties which are determined using the standard uncertainty of equipment used in experiment. The motion under static condition are analyzed using geometric errors. The five geometric errors except the linear displacement error are measured using optimal measurement system which is designed to enhance the standard uncertainty of geometric errors. In addition, the motion under dynamic conditions are analyzed with respect to the conditions with different feed rate of the stage. The experimental results shows that the feed rate of stage has a significant effect on straightness motions.