• Journal of Biomedical Engineering Research
• /
• v.28 no.6
• /
• pp.744-749
• /
• 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.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.4
• /
• pp.91-99
• /
• 2018

Mechanical Properties of Rock Slope as a safe and effective interpretation should be thoroughly investigated. Clinometer, however, this new measurement due to the restrictions of the research for the joint orientation is needed. In this study, characteristics of the joint orientation can be used to analyze the joint orientation of developing a joint survey system that can be applied to the field. The system is developed and Analysis software to hardware. Hardware is composed to measure the joint orientation of measuring module, measuring the transfer of data transfer module. From the software is measuring module from the data to analyze the orientation of the joint development, and drone joint orientation survey system named. Can not be measured by the investigation, including regional development approach is a system that has been difficult if the Field Application of the lab test results of the joint orientation and effectively.

• The Korean Journal of Pain
• /
• v.14 no.2
• /
• pp.218-224
• /
• 2001

Background: Response to diagnostic blocks does not consistently predict the outcome of interventional facet denervation. We investigated the relationship between pain relief by the percutaneous radiofrequency denervation of the lumbar zygapophysial joints with the result of facet joint diagnostic local anesthetic injection in patients with back pain originating from the lumbar zygapophysial joint. Methods: There were 35 patients enrolled, with ranging in age from 25 to 76 years ($52.6{\pm}12.7$ years, mean ${\pm}$ SD). We studied 7 men (20%) and 28 women (80%). All patients underwent double diagnostic block of $L_{3/4}$, $L_{4/5}$ and $L_5-S_1$ facet joint with 0.5% bupivacaine. The 35 patients fell into the following group. (1) Group A (n = 16): those who felt clear relief (pain free with Likert scale) from the double diagnostic block (2) Group B (n = 19): 11 patients who were always equivocal in their response to the double diagnostic block and 8 patients who were either pain free or equivocal in their response to the double diagnostic block. All 11 patients were done the facet joint denervation. The effect on the pain was evaluated with 4 point Likert scale 1, 6 and 12 weeks after the procedure. We evaluated the relationship between the pain response to diagnostic block and the pain relief with facet joint denervation. Results: Significant correlation was observed between the response to diagnostic block and pain relief with facet denervation (P < 0.05). We found no correlation between the categories of spinal operation and pain response to facet denervation (P value > 0.05). Conclusions: A satisfactory result of lumbar facet joint denervation can be obtained in many patients, especillay in patients whose pain were relieved by the diagnostic double facet joint block. It may be said that facet joint denervation for mechanical low back pain using radiofrequency thermocoagulation is a safe, easy, and repeatable technique.

• Korean Journal of Applied Biomechanics
• /
• v.14 no.1
• /
• pp.133-144
• /
• 2004

The purpose of this study was to analyze the joint moment on lower extremity during a developpe devant. Data were collected by Kwon3D, KwonGRF program. Two professional modem female dancers were participated in this experiment. Subjects performed a developpe devant in meddle heights. On the axes of X, Y, Z, it was shown that the maximum joint moment was occurred in hip joint. The moments are plotted during developpe devant. The ankle muscles generate a plantar flexion moment and the knee muscles generate a flexion moment and The hip muscles generate a extension moment. So these muscles of joint muscles were known to play a key role in keeping the body balance while doing developpe devant. In addition adduction moment occurred at hip, knee, an ankle in the order of amount, we could assume from this data that him out motion started from the hip joint. There was small active turn out possible below the hip joint. A small amount of extra turn out could be obtained when standing because of flexion between the foot and floor, which could be used to give a passive external rotation force to the whole leg and this could produce a rotation between the knee and foot. This passive external rotation could produce very damaging results. Therefore, lower extremity joint muscles such as hip, knee, and ankle muscle should be trained to keep the body balance and prevent injury during developpe devant performance. And for the safe and perfect turn ort performance, hip joint abduction, the most important external rotating muscle for him out is needed to train and full stretching should be done in advance.

• Journal of Biomedical Engineering Research
• /
• v.31 no.2
• /
• pp.151-161
• /
• 2010

Soft Golf is a newly developed recreational sport in our research team 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. The purpose of this study is to analyze ground reaction force(GRF) and joint angle during soft Golf club and regular golf club swing. The GRF of golf swing was recorded by 3-D motion analysis system and forceplate. The joint angle of golf swing was obtained from computer simulation model. The GRF and joint angle of golf swing are used to analysis of golf swing pattern. The pattern of GRF and joint angle during soft golf club swing was similar to that during regular golf club swing. This result means that soft golf club reduces the risk of injury and has an effect on similar entertainment of regular golf.

• Journal of Welding and Joining
• /
• v.14 no.2
• /
• pp.36-45
• /
• 1996

Fatigue strength of the spot welded lap joint is considerably influenced by corrosive environments. Particularly, the chloride and the sulfide are most injurious to strength of the spot welded lap joint. Therefore, there is a need to evaluate its effect to corrosion fatigue strength for safe life design of spot welded structures. In order to evaluate their corrosion fatigue strength, corrosion fatigue tests on the spot welded lap joints of the uncoated and the coated high strength steel sheets were conducted in air and in 10% NaCl solution. Corrosion fatigue strength of the uncoated specimens were entirely lower than the coated one in NaCl solution, but those of the coated specimens in NaCl solution were lower than in air. And stress distribution in single spon welded lap joint subjected to tension-shear load was investigated by the finite element method. Using these results, we tried to evaluate corrosion fatgue strength of the various spot welded lap joints with maximum stress $\sigma_{max}$ at edge on loading side of the spot welded lap joint. We could find that corrosion fatigue strength could be quantitatively and systematically rearranged by $\sigma_{max}$.

• Journal of Oral Medicine and Pain
• /
• v.39 no.4
• /
• pp.152-155
• /
• 2014

Temporomandibular joint (TMJ) dislocation is defined that the disc-condyle complex is positioned anterior to the articular eminence in the open mouth position, and is unable to return to a normal closed mouth position without a manipulative maneuver. TMJ dislocation can recur habitually and result several problems to patients such as discomfort, pain, fear, and anxiety. The only definitive treatment for TMJ dislocation is surgical alteration of the joint itself. In most cases, however, a surgical procedure is far too aggressive for the symptoms experienced by the patient. In addition, the effect of surgical treatment may be insufficient, and the recurrence have been reported. It is also possible to develop several complications after surgical treatment. Therefore much effort should be directed at supportive therapy in an attempt to eliminate the disorder or at least reduce the symptom to tolerable levels. Through this cases the authors present favorable treatment outcome using occlusal splint with the patient of TMJ dislocation. Occlusal splint therapy can be considered as easy, safe, and useful non-invasive modality to treatment of TMJ dislocation.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.43 no.6
• /
• pp.113-119
• /
• 2001

Experiments on the yield strength of pipe connectors made of metal wire, joint pins, pole pipes, multi span insertion joints, and T-clamp joints used in pipe houses were conducted. The strength of connections of a pipe connector made of metal wire was adequate but it had a big difference according to loading direction. Therefore as it is installed, its direction should be taken into consideration. The collapse load of pipes connected with a joint pin was lower than that of single pipes. In the part of frame member at which the great bending moment occurs, the use of joint pin should be avoided. Also experimental results showed that pole pipes for use in a part of frame buried under the ground were safe, and the strength of multi span insertion joints should be increased. The resistant moment of T-clamp was about 13.7% of a single pipe. In case that the external forces acting on left and right rafter are different. a unsymmetrical rotational force is produced at the multi span joint. If it is expected that the actual bending moment on the multi span joint is larger than resistant moment of T-clamp, a reinforcement to safely resist the rotational force is required.

• The Journal of Korea Robotics Society
• /
• v.3 no.4
• /
• pp.315-322
• /
• 2008

A new soft finger mechanism using a spring as a backbone is proposed in this work. It is a 4 DOF mechanism that consists of a spring and 3 cylinders, which behave like joints with 3 up-and-down rotations and 1 left-and-right rotation. To control each joint, cylinders have small holes in their cross-sectional areas, and wires of different length are penetrated into these holes. We can control each joint by pulling the corresponding wire. The forward kinematics is solved by using the geometry of mechanism. And the relationship (Jacobian) between the linear velocity of the wires and the joint angular rate is obtained. A virtual simulator is developed to test the validity of the kinematic model. In the experiment, first, the position control is conducted by tracking a given trajectory. Second, to verify the flexibility and safety, we show that the soft finger deflects in a safe manner, in spite of the collision with environment.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.7 no.3
• /
• pp.36-40
• /
• 2008

This study is analyzed by the simulation of automotive steering system. The maximum equivalent stress of $2.2418{\times}109Pa$ and the maximum total displacement of 0.014929m are shown at the universal joint and its lower part respectively. As the minimum cycle of 34.047 is shown at the universal joint in case of fatigue analysis, it is possible to have greatest damage at this part. In case of natural frequency analysis at vibration, its frequency of 47 to 59Hz is occurred generally. The maximum total displacement of 0.5m is shown at handle on the natural frequency of 57 to 58Hz. And the displacement over 2m is shown at the lower part of universal joint on the natural frequency of 58 to 59Hz. As the basis of the simulation analysis of steering system, passenger's comfort of car body can be improved in the design of practical part and the design effect necessary to safe driving can be promoted.