• Proceedings of the ESK Conference
• /
• 1995.10a
• /
• pp.141-155
• /
• 1995

To understand kinetic characteristics during the process of initation of gait from standing, from the visual cue to toe off of the stance limb, vertical ground reaction forces(GRF) and center of pressure(COP) during gait initation period were evaluate with two force platforms placed side by side in thirty two adults(young 16, elderly 16, each mean age 27.79 and 51.70 years) with no history of 7 neuromusculo-skeletal abnormality. Gaint initation period of swing and stance limbs, percentage of gait initiation period and ratio of the vertical forces to body weight at each peak of the vertical forces of both limbs, and also movement of net COP were measured and described. 2 groups, one of 16 young adults and another of 16 elderly adults, were compared statistically. These data showed the increase of initiation of gait period and the decrease of movement of net COP, nd also can now be used as a part of database when initation of gait in subjects with neuromusculoskeletal abnormalities need to be evaluated.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.9
• /
• pp.1262-1269
• /
• 2004

This study predicts muscle forces acting on the lower extremity when the knee joint is in deep flexion. The whole body was approximated as a link model, and then the moment equilibrium equations at the lower extremity joints were derived far given reaction farces against the ground. Measurement of deep flexion was carried out by placing ten markers on the body. This study calculated the moment acting at each Joint from the equations of force and moment, classified the complicated muscles around the knee joint, and then predicted the muscle forces to balance the joint moment. Two models were proposed in this study: the simpler one that consists of three groups of muscle and the more detailed one of nine groups of muscle.

• Proceedings of the KAIS Fall Conference
• /
• 2011.05b
• /
• pp.529-532
• /
• 2011

A theoretical model has been studied to describe the sound radiation analysis for structure vibration noise of vehicle tires under the action of random moving line forces. When a tire is analyzed, it had been modeled as curved beams with distributed springs and dash pots that represent the radial, tangential stiffness and damping of tire, respectively. The reaction due to fluid loading on the vibratory response of the curved beam is taken into account. The curved beam is assumed to occupy the plane y=0 and to be axially infinite. The expression for sound power is integrated numerically and the results examined as a function of Mach number, wave-number ratio and stiffness factor. The experimental investigation for structure vibration noise of vehicle tire under the action of random moving line forces has been made. Based on the Spatial Transformation of Sound Field techniques, the sound power and sound radiation are measured. Results strongly suggest that operation condition in the tire material properties and design factors of the tire govern the sound power and sound radiation characteristics.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.8 no.6
• /
• pp.530-536
• /
• 2016

The number of fabrication shop for spherical type LNG tank is proportional to that of the tank radius to be constructed. Due to limitation of facility investment including building sites, it is practically difficult to fabricate various size tanks with perfectly spherical shape in the yards. The efficient method to be capable of increasing cargo tank volume is to extend vertically the conventional spherical type LNG tank by inserting a cylindrical shell structure. The main purpose of this study is to derive related equations on forces generated on spherical type LNG tank with central cylindrical part under various static loadings in order to establish the simplified analysis method for the initial estimate. In this study, equations on circumferential and meridional force have been derived and verified by relations with the reaction forces per unit length of equator.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.13 no.1
• /
• pp.132-139
• /
• 2005

The driving position of head restraints and the relative risk of neck injury were studied in the computer simulation. MADYMO human model with the detail neck model was used to define the magnitude and direction of internal forces acting on the cervical spine during rear-end impact and to determine the effect of the initial position of the occupant's head with respect to the head restraints. Maximum reaction forces were generated during the head contact to the restraint and relatively large forces were generated at each spinal components in lower cervical spine in proportion to backset and height distance increasement.

• Tribology and Lubricants
• /
• v.24 no.5
• /
• pp.241-249
• /
• 2008

This paper describes the tribological effects on the nonlinear behavior of a spur gear pair with one-way clutch according to the direct contact elastic deformation model over a wide range of speeds, considering the hydrodynamic effects. The effects of various lubrication parameters, such as viscosity, film width, and friction, on the nonlinear dynamic behavior were analyzed. Forces due to the entraining velocity and the hydrodynamic friction were about two orders smaller than normal forces over the whole speed range. While the viscosity has a strong effect on the behavior of gear pair systems, friction has very little effect on torsional behavior. The inclusion of the hydrodynamic effect facilitates nonlinearity by increasing the overlap and damping, as well as decreasing elastic deformation and tooth reaction forces.

• Earthquakes and Structures
• /
• v.20 no.2
• /
• pp.225-238
• /
• 2021

Supplemental passive dampers are widely employed to improve the structural performance of buildings under seismic excitations. Nevertheless, the added damping could be counter-productive if the axial forces induced by the damper reaction forces are not routed properly in the columns. A few researchers engaged to optimize the width-wise damper arrangement to improve the delivered path of the axial column forces. However, most of these studies are limited under the design-based seismic level and few of them has evaluated the collapse performance of buildings under strong earthquakes. In this paper, the strategic width-wise placement method of viscous dampers is explored regarding the building performance under collapse state. Two realistic steel buildings with different storeys are modelled and compared to explore higher mode effects. Each building is designed with four different damper arrangement scenarios based on a classic damper distribution method. Both a far-fault and a near-fault seismic environment are considered for the buildings. Incremental Dynamic Analysis (IDA) is performed to evaluate the probability of collapse and the plastic mechanism of the retrofitted steel buildings.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.1515-1516
• /
• 2013

• Tribology and Lubricants
• /
• v.11 no.2
• /
• pp.24-33
• /
• 1995

This paper presents the contact stress distributions between the multi-contact bodies and the total reaction forces for various types of contact geometry for multi-load slewing ring bearings. The FEM results indicate that the slope of the roller type of slewing ring bearing has slightly steeper than that of the ball type. This is because the roller type wire race bearings is stiffer than the ball type bearing. The total reaction force of ball type slewing bearing shows much higher than that of wire race slewing bearings.

• Communications of the Korean Mathematical Society
• /
• v.14 no.2
• /
• pp.429-440
• /
• 1999

In this paper an electrochemistry model which consists of three charged species is considered. A dissociation-association reaction is allowed to take place between these species. The species of ions diffuse owing to concentration gradients and migrate because of electric forces. We prove that any initial distribution of species concentrations will settle down to the unique steady state as time becomes large.