• Journal of the Korean Society of Physical Medicine
• /
• v.7 no.2
• /
• pp.205-212
• /
• 2012

Purpose : The aim of this study was to investigate the relationship between weight-supporting asymmetry and gait symmetry in patients with stroke. Methods : Sixty two stroke patients with hemiplegia stood quietly with eye opens on a force platform to calculate weight-supporting asymmetry from vertical reaction force. The GAITRite was used to evaluate their gait parameters. The data were analyzed using Pearson correlation. Results : The results of this study was showed that the medio-lateral index (ML) was correlated with symmetry rate (SR), symmetry index (SI), and Gait asymmetry (GA) of step time and length but stronger correlation with spatial gait symmetry than temporal symmetry. In gait symmetry, step length has stronger correlation with weight-supporting asymmetry than step time. Conclusions : The results of this study shows weight-supporting asymmetry was correlated with more spatial gait symmetry than temporal symmetry.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.886-889
• /
• 2002

Finite Element Method for 3-D static loaded passenger car tire on the rigid surface is performed for studying the stiffness of tire to compare with experimental data. The tire elements used for FEM are defined each component to allow an easy change for the design parameters. Also, a hyperelastic material which is composed of tread and sidewall has been used to consider a large deformation of rubber components. The orthotropic characters of rubber-cord composite materials are used as well. The air pressure, a vertical and a lateral load are applied step by step and iterated by Modified Newton method for geometric and boundary condition nonlinear simulation. This study shows nonlinear analysis method for tire and the bearing capacity of tire due to the external force.

• Journal of the Korean Society for Railway
• /
• v.4 no.4
• /
• pp.131-137
• /
• 2001

The dynamic behavior of high speed train is very important because of its safety and passengers' ride comfort. The railway vehicle is composed of many suspension components, such as 1st springs, 1st dampers, 2nd springs and 2nd dampers, that have an influence on the dynamic characteristics of high speed train. Also, the wheel/rail shapes and the track geometry affect the dynamic behavior of high speed train. This paper reviews the dynamic behavior of KHST in the KTX test line. The VAMPIRE program is used for this simulation. The simulation results are within the limits of safety criteria. Thus the KHST can operate safely at 350 km/h in the KTX test line.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.711-714
• /
• 2001

As the life cycle of the vehicle become shorter, the method that reduce the development time of new model become more important. In this reason, the development of the simulator that provides similar environment with the actual vehicle road characteristics is increasing. In this paper, the multi-axis simulator is designed and analyzed by kinematic method. The simulator has a function simulating the 3 load elements; vertical, longitudinal, and lateral force respectively and simultaneously. The result of this paper can be used for developing the multi-axis simulator linkage.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.288-291
• /
• 2001

Vehicle evaluation is performed on the proving ground, and durability test and dynamic test cost lots of money and time. Doing replace real vehicle experiment with similar experiment environment, it will take us much more useful advantages. Suspension simulator is required the robust and high-reliability and used widely. But it's natural of high-leveled control technique to manage to be fitted fluid system's property and complex that is for the lack of self-damping, nonlinearity, compressibility. In designing and evaluating simulator, it is important to understand the capability of kinematic and static performances. In this paper, an kinematic modeling and analysis has been presented using ADAMS to design that can reproduce longitudinal, lateral, and vertical force.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.04a
• /
• pp.156-160
• /
• 1996

A vibrating angular rate sensor with tuning fork type resonator of microstructure (940*820 .mu. m$^{2}$) was designed and will be fabricated by polysilicon surface micromaching. The angular rate sensor is driven in a lateral direction by electrostatic force of comb drive electrodes, and vertical vibrations of the sensor, thich is detected capacitively, are produced by Coriolis forces due to an external angular rate. Mechanical Q factors and a difference between the frequencies of the two resonant modes, the driving mode and detecting mode, play a great role in increasing the sensitivity of the sensor. To be a highly sensitive sensor, it was designed to have as small frequency discrepancy of the two resonant modes as possible. Finite element method was used for the modal analysis. Several design parameters were selected and their contributions to the modal frequencies were investigated. A method was presented for tuning the detecting mode frequency by DC bias on the drive electrodes.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.05a
• /
• pp.384-388
• /
• 2004

This study presents parametric studies for design of tiling mechanism to be used in 180km/h tilting train. The titling mechanism is composed of 4 links, a tilting bolster and an electro-mechanical actuator. First we have determined the installation height of tilting actuator using 3D tilting bogie modeling. Secondary, we verified movements of the tiling center and train body CG along variation of upper and lower span length. From this study, we obtained the upper and lower span length to minimize the lateral and vertical motion of CG of train body. Finally, we evaluated the tilting actuator force and power required to tilt the train body to $\pm$8$^{\circ}$.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2013.04a
• /
• pp.83-88
• /
• 2013

The purpose of this study is to develop the algorithm for dynamic interaction analysis of submerged floating tunnel and vehicles. The dynamic behavior characteristic of submerged floating tunnel is certainly different with general structures, because the submerged floating tunnel is floating in the middle of water, and subjected to constant buoyance. Therefore the analyses in various aspects should be carried out to secure structural stability and practicality of structures. To conduct the dynamic interaction analysis, the structure is modeled by commercial FEM program ABAQUS to investigate modal characteristic. Also the added mass concept is applied to represent the inertial force by a fluid, and then dynamic interaction analyses are conducted with superposition method when the KTX is moving along the submerged floating tunnel. And the time histories are presented for vertical and lateral displacement at the center of the tunnel.

• Proceedings of the KSR Conference
• /
• 2006.11b
• /
• pp.1184-1189
• /
• 2006

Railway vehicle have three translational motions-longitudinal, vertical and lateral, and three rotational motions-rolling, pitching and yawing caused by track irregularity, wheel and rail characteristic, dynamic behaviors etc. The rolling motion in vehicle mainly happens in cases of the vehicles stationary and running on canted track. When the vehicle positioned in stationary on canted track, vehicle is inclined toward inside of installed cant due to gravity component. When the vehicle has running on a track with cant deficiency, vehicle is inclined toward outside of installed cant due to centrifugal force. The roll coefficient(s) is defined as the ratio between the angle of inclination of the vehicle($\eta$) and the angle of the rail level($\alpha$). This paper has noted the test method, test result and analysis result to calculate the roll coefficient according to UIC505-5, international standard

• The Journal of Korean Academy of Prosthodontics
• /
• v.31 no.3
• /
• pp.303-316
• /
• 1993

The purpose of this study was to analysis the stress distribution induced by three unit PFM bridges and various cantilever bridges replacing maxillary latersal incisor. The simplified two-dimensional photoelastic models used for this study was contructed in the folio- wing way. CR/R ratio was designed to be 1 : 1, 1 : 1.25 and 1 : 1.5. The pontics of cantilever bridge supported by maxillary canines consisted of wrap-around type, rest-extension type, and simple type. 3-unit PFM bridge was constructed with traditional method. 1kg vertical static load was applied on the center of the incisal edge of the pontic. The stress pattern was examined and recorded by photography. The results obtained were as follows ; 1. The magnitude of stress on the abutment root apex area of a traditional 3-unit bridge was the lowest. 2. The model of cantilevered pontic with a rest showed the relatively well distributed stress around the abutment tooth. The model with simple pontic generated the greatest stress concentration in the supporting structure of the abutment tooth. 3. As the height of bone level reduced, the rotational and vertical force increased around the abutment tooth. 4. The stress concentration of the 3-unit bridges occured on the root apex and stress concentration of the cantilever briage occured on the root apex and cervix area, 5. In the case of the cantilever bridge, stress concentrated distally on the root apex area of the abutment tooth and additional stress was observed mesially on the upper part of the root. Especially in the case of the simple pontic, was phenomenon was more apparent than the others. 6. Force applied to cantilevered pontic was transmitted to the adjacent central incisor through the contact surface. Stress was markedly observed on the mesial cervix area in the case of simple pontic and on the root apex area in the case of wrap-around type and rest-extension type.