• Journal of the Korean Society for Precision Engineering
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• v.26 no.2
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• pp.126-132
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• 2009

This study examined the differences in spatio-temporal parameters, joint angle, ground reaction force (GRF), and joint power according to the changes of gait speed for trans-tibial amputees to investigate the features of the energy-storing foot for sports. The subjects walked at normal speed and at fast speed, wearing a single-axis type foot (Korec) and an energy-storing foot for sports (Renegade) respectively. The results showed that Renegade yielded faster gait speed as well as more symmetric gait pattern, compared to Korec. However, as gait speed was increased, there was no significant difference in kinematics, ground reaction force, and joint power between two artificial foots. This was similar to the results from previous studies regarding the energy-storing foot, where the walking velocity and gait symmetry have been improved. Nevertheless, the result of this study differed from the previous ones which reported that joint angle, joint power, and GRF increased as the gait speed increased except spatio-temporal parameters.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.183-190
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• 2008

This paper deals with the characteristics of idle vibration due to the type of constant velocity joints. Based on the kinematics model of constant velocity joints, a offset between the tripod center and tullip center plays a important role in generating unwelcome forces. Moreover, it induced additional forces in lateral direction of a vehicle movement according to the angle of the spider in idle vibration. The difference of mass for each constant velocity joint types affect the natural frequency of the driveshaft and the powertrain. When the static torque is applied to the constant velocity joints, the natural frequencies of the driveshaft are reduced nearby 50Hz. There will be a big opportunity that the dirveshaft and constant velocity joints would be a transfer path of idle vibration at D or R gear range. Experiments indicate that TJ type is better than SFJ and DOJ in idle vibration.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.2
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• pp.220-227
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• 1998

In substitution of beam-nonlinear spring model for real-car, it may have errors due to complicated characteristics of joint and overestimation of joints stiffness. In this research, a method for the joint modeling was suggested by nonlinear static and dynamic analyses of beam and shell joint models and verified by the application of accomplished joint modeling method to simplified full car model. In consequence, modified simplified full car model was improved in local acceleration and rigid wall force. Finally, the frontal crash analyses with the dummy were established and the accelerations of accelerations of head, chest and pelvis had good agreements with those of shell model.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.8
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• pp.1980-2000
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• 1993

The stresses and torque transmission capabilities of adhesively bonded circular, hexagonal and elliptical lap joints were analyzed by the finite element and compared with the experimental results. The adherends of the joints were composed of carbon fiber/epoxy composite shafts and steel shafts. In calculating the torque transmission capabilities, the linear laminate properties of the composite material and the nonlinear shear properties of the adhesive were used. Using this method, the torque transmission capabilities of adhesively bonded lap joints could be obtained within 10% error compared to the experimental results except some single lap joints. The experiments revealed that the hexagonal joint had the best torque transmission capability from the single lap joints and the double lap joint had better torque transmission than the single lap joint.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1310-1315
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• 2003

Severe osteoarthrosis of the knee joint often requires total knee arthroplasty (TKA) to yield adequate knee function. The knee joint with TKA is expected ideally to restore the characteristics, however, this is not necessarily true in the clinical cases. In this study the motions of the intact joint and the joint after TKA were investigated numerically using computer simulation. For active knee extension from 90 degrees of flexion to full extension, the intact knee joint exhibited anterior tibial translation near the full extension while it showed only rotation for other flexion angles. Physiologic external rotation of the tibia near full extension was also noted in the analytical model. The analysis of the tibial insert of three different shapes (flat, semicurved, and curved types) demonstrated characteristic rotational and sliding motions as well as different contact forces.

• Proceedings of the KWS Conference
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• 1997.10a
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• pp.81-85
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• 1997

This paper was conducted the fatigue crack growth test on the base metal and weld joint of bimaterial(carbon-stainless steel), carbon steel and stainless steel. As the result, the fatigue crack growth rate of weld joint on the stainless-stainless steel is faster than stainless base metal, and weld joint on the carbon-carbon steel heat affected zone is slower than carbon base metal. And fatigue crack growth rate of carbon-stainless steel weld joint and heat affected zone is similar to the behavior of stainless base metal. In conclusion, weld joint of bimaterial is stable in the fatigue crack growth behavior.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.1058-1062
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• 1996

The assessments of weld defects by fracture mechanics are performed for design of welded Joints. In general, butt, T-type, and L-type welded joint are useful for welding structure. When linear weld defects are in welded joint, stress intensity factors for each joints are calculated by finite element method. Analysis results are shown for the fracture modes and characteristics of joint types. And they are founded for the weaken order of welded joints being T-type, butt, L-type.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.3
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• pp.104-109
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• 1998

This document is a experimental study on fatigue life of brace mounting weld joint. A brace is used to put sub-frame together on the main frame with high strength bolts. It has low fatigue life so a patch is in need for improving a fatigue characteristics of welded joint in brace mounting This paper presents the most pertinent patch size for truck. For this, a critical stress is computed at the point of fatigue crack occurred on truck frame by finite Element Analysis. Using by this critical stress. Designers are able to determin whether fatigue crack is occurred and are able to select a pertinent patch type. And then, with a selected patch type, structural joint stiffness was estimated to compare to the conventional and other patch type or brace mounting Finally, fatigue test were performed to prove a suitability of selected prototype compare with the conventional and other patch type or brace mounting.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.9
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• pp.188-195
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• 2004

Severe osteoarthrosis of the knee joint often requires total knee arthroplasty(TKA) to yield adequate knee function. The knee joint with TKA is expected ideally to restore the characteristics, however, this is not necessarily 1.ue in the clinical cases. In this study the motion of the intact joint and the joint after. TKA were investigated numerically using computer simulation. For active knee extension from 90 degrees of flexion to full extension, the intact knee joint exhibited anterior tibial translation near the full extension and it showed only rotation at other flexion angles. Physiologic external rotation of the tibia near full extension known as screw home movement was also noted in the analytical model. The analysis of the tibial insert of three different shapes (flat, semicurved, and curved types) demonstrated characteristic rotational and sliding motion as well as different contact forces.

• Journal of Information Processing Systems
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• v.15 no.4
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• pp.785-796
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• 2019

Due to the view point, illumination, personal gait and other background situation, person re-identification across cameras has been a challenging task in video surveillance area. In order to address the problem, a novel method called Joint Bayesian across different cameras for person re-identification (JBR) is proposed. Motivated by the superior measurement ability of Joint Bayesian, a set of Joint Bayesian matrices is obtained by learning with different camera pairs. With the global Joint Bayesian matrix, the proposed method combines the characteristics of multi-camera shooting and person re-identification. Then this method can improve the calculation precision of the similarity between two individuals by learning the transition between two cameras. For investigating the proposed method, it is implemented on two compare large-scale re-ID datasets, the Market-1501 and DukeMTMC-reID. The RANK-1 accuracy significantly increases about 3% and 4%, and the maximum a posterior (MAP) improves about 1% and 4%, respectively.