• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.827-831
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• 2008

In this paper, kinematic analysis for a planar 3-DOF redundant stage which has four actuators is presented by using SimMechanics software package. SimMechanics is a block sets of the Matlab/Simulink package. The SimMechanics enables a simplified model for a complex kinematic mechanism, since kinematic relationship between joints and linkages for the kinematic chains are expressed as line vectors and block diagrams. Here, positional error and limit values of movement ranges of the stage are evaluated by using the SimMechanics. The validity of the kinematic characteristics model was compared with theoretical kinematic analyses for the 3-DOF stage.

• 소성∙가공
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• 제17권8호
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• pp.579-585
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• 2008

Numerous experimental investigations on metallic materials and solid polymers have shown that relaxation behavior is nonlinearly dependent on prior strain rate. The stress drops in a constant time interval nonlinearly increase with an increase of prior strain rate. And the relaxed stress associated with the fastest prior strain rate has the smallest stress magnitude at the end of relaxation periods. This paper deals with the performance of three classes of unified constitutive models in predicting the characteristic behaviors of relaxation. The three classes of models are categorized by a rate sensitivity of kinematic hardening rule. The first class uses rate-independent kinematic hardening rule that includes the competing effect of strain hardening and dynamic recovery. In the second class, a stress rate term is incorporated into the rate-independent kinematic hardening rule. The final one uses a rate-dependent format of kinematic hardening rule.

• 국제물리치료학회지
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• 제8권2호
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• pp.1142-1145
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• 2017

The purpose of this study was to examine the effect of kinematic taping on respiratory muscle strength in smokers. Twenty - five university students who smoke were involved in the study. All participants were applied to kinematic taping to breathe deeply again. Subjects sit on their backs straight up and place their hands on their thighs. Tape 1 is applied from the lower prominent neck vertebrae(seven cervical vertebra) inward and downward, past shoulder blade, around ribs to the lower tip of sternum. Tape 2 extends to the lower, outer edge of shoulder blade, around ribs to the lower tip of sternum. Respiratory muscle strength was measured with Micro Mouth Pressure Measurement before and after taping. The application of kinematic taping significantly improved the inspiratory and expiratory muscle strength (p<.05). These findings suggest that kinematic taping effective in improving respiratory muscle strength and deep breathing.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.947-952
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• 2021

In this paper, the simplified kinematic error model for Delta parallel robot is presented, which can enable the analytical forward kinematics essentially for kinematic calibration calculations instead of the numerical one. The simplified kinematic error model is proposed and the forward kinematics including the error parameters is analytically derived. The kinematic calibration algorithm of the Delta parallel robot with 90 degree arrangement using laser tracker and the experiment result are presented.

• 한국측량학회지
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• 제11권2호
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• pp.79-87
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• 1993

각종 건설공사와 국토종합개발계획을 위한 3차원 지형정보의 효율적인 획득에 대한 중요성이 날로 강조되고 있는 가운데, GPS를 이용한 3차원 위치결정의 정확도 분석 및 응용 연구에 많은 관심이 집중되고 있다. 본 연구에서는 kinematic GPS에 의한 지형정보구축의 효용성 및 응용 가능성을 입증하고자 삼각, 삼변측량 및 static GPS 측량을 수행하고 그 성과를 kinematic GPS 측랑성과와 비교 분석하였다. 그 결과 기선길이 1.5km 정도의 소규모 지역에서 kinematic GPS 측량으로도 static에 대해 기선의 경우 6mm 이하, 위도, 경도의 경우 2/10,000-4/10,000초, 고도의 경우 20cm 미만의 차로 3차원 위치를 결정할 수 있었다. 또한 종래의 측량방법과 비교해 볼 때 수평위치에서 l/l,000-3/l,000초 정도의 접근양상을 보였다. 따라서 이를 이용한 지형도 작성 및 G1S와 연계한 데이타베이스 구축의 효용성 및 실용가능성을 기대할 수 있을 것이다.

• 대한의용생체공학회:의공학회지
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• 제28권6호
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• pp.744-749
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• 2007

Kinematic and kinetic analysis has been performed for Soft Golf swings utilizing realistic three dimensional computer simulations based on three dimensional motion tracking data. Soft Golf is a newly developed recreational sport in South Korea aimed to become a safe and easy-to-learn sport for all ages. The advantage of Soft Golf stems from lighter weight of the club and much larger area of the sweet spot. This paper tries to look into kinematic and kinetic aspects of soft golf swings compared to regular golf swing and find the advantages of lighter Soft Golf clubs. For this purpose, swing motions of older aged participants were captured and kinematic analysis was performed for various kinematic parameters such as club head velocity, joint angular velocity, and joint range of motions as a pilot study. Kinetic analysis was performed by applying kinematic data to computer simulation models constructed from anthropometric database and the measurements from the participants. The simulations were solved using multi-body dynamics solver. Firstly, the kinematic parameters such as joint angles were obtained by solving inverse dynamics problem based on motion tracking data. Secondly, the kinetic parameters such as joint torques were obtained by solving control dynamics problem of making joint torque to follow pre-defined joint angle data. The results showed that mechanical loadings to major joints were reduced with lighter Soft Golf club.

• 대한기계학회논문집
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• 제17권8호
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• pp.1883-1897
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• 1993

Interactive computer-aided analysis of mechanical systems has recently been undergoing an evolution due to highly efficient computer graphics. The industrial implementation of state-of-the-art analytical developments in mechanisms has been facilitated by computer-aided design packages because these rigid-body mechanism analysis programs dramatically reduce the time required for linkage design. This paper proposes a component modular approach to computeraided kinematic motion analysis for general planar multiloop mechanisms. Most multiloop mechanisms can be decomposed into serveral components. The kinematic properties (position, velocity, and acceleration) of every node can then be determined from the kinematic analysis of the corresponding component modules by a closed-form solution procedure. In this paper, 8 types of modules are defined and formulations for kinematic analysis of the component modules are derived. Then a computer-aided kinematic analysis program is developed using the proposed approach and the solution procedure of an example shows the effectiveness and accuracy on the approach.

• Journal of Positioning, Navigation, and Timing
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• 제9권1호
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• pp.15-21
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• 2020

In October 2019, the European Galileo navigation system operates a total of 24 satellites, two of them are in the testing phase. There are enough satellites in operation to enable precise point positioning (PPP) using Galileo signals. The number of visible satellites for Galileo in South Korea is investigated. In addition, to assess the latest performance of the Galileo kinematic PPP, data received at DAEJ reference station from October 1 to October 7, 2019, are analyzed. Galileo kinematic PPP presents some results in two categories, single-frequency PPP (SPPP) and dual-frequency PPP (DPPP). The positioning accuracy for Galileo kinematic SPPP solutions is less than 1 m root mean square (RMS) in all direction components. The Galileo kinematic DPPP achieves the positioning accuracy with an RMS value of less than 7 cm in all direction components. The results show that the latest performance of Galileo kinematic PPP at DAEJ station in South Korea is still relatively poor compared to GPS kinematic PPP. However, the residuals of Galileo code measurements are smaller than those of GPS code measurements.

• 한국운동역학회지
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• 제17권4호
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• pp.157-167
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• 2007

The purpose of this study was to analyze kinematic techniques in the woman's 100m hurdle. In order to find the kinematic parameters, a 3-D video system for kinematic analysis-kwon3d 3.1(Kwon3D Motion Analysis Program Version 3.1)-was used. Eight JVC video cameras(GR-HD1KR) were used to film the performance of Lee Yeon-Kyoung at a frame rate of 60fields/s. The kinematic characteristics from the first hurdle to last hurdle were analyzed at the clearing hurdle spots such as distance, velocities, heights and angles. The real-life three-dimensional coordinates of 20 body landmarks during each phases were collected using a Direct Linear Transformation procedure. After analyzing the kinematic variables in the 100m hurdle run, the following conclusion were obtained; Lee Yeon-Kyoung had to maintain constant stride lengths between hurdles and increase takeoff distance before clearance and shorter landing distance after clearance. She also had to hit the correct takeoff point in front of the hurdle and extend the lead leg at the moment of landing in order to minimize the loss of velocity. She had to sprint between hurdles as fast as possible over 8m/s and run powerful first stride and shortened third stride preparing for the following hurdle clearances.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.355-360
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• 2002

To calibrate a non-redundantly actuated parallel mechanism, one can find actual kinematic parameters by means of geometrical constraint of the mechanism's kinematic structure and measurement values. However, the calibration algorithm for a non-redundant case does not apply fur a redundantly actuated parallel mechanism, because the angle error of the actuating joint varies with position and the geometrical constraint fails to be consistent. Such change of joint angle error comes from constraint torque variation with each kinematic pose (meaning position and orientation). To calibrate a redundant parallel mechanism, one therefore has to consider constraint torque equilibrium and the relationship of constraint torque to torsional deflection, in addition to geometric constraint. In this paper, we develop the calibration algorithm fir a redundantly actuated parallel mechanism using these three relationships, and formulate cost functions for an optimization algorithm. As a case study, we executed the calibration of a 2-DOF parallel mechanism using the developed algorithm. Coordinate values of tool plate were measured using a laser ball bar and the actual kinematic parameters were identified with a new cost function of the optimization algorithm. Experimental results showed that the accuracy of the tool plate improved by 82% after kinematic calibration in a redundant actuation case.