• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.6
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• pp.39-47
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• 2010

A research of image-based articulated pose estimation has some problems such as detection of human feature, precise pose estimation, and real-time performance. In particular, various methods are currently presented for recovering many joints of human body. We propose the novel numerical inverse kinematics improved with the UKF(unscented Kalman filter) in order to estimate the human pose in real-time. An existing numerical inverse kinematics is required many iterations for solving the optimal estimation and has some problems such as the singularity of jacobian matrix and a local minima. To solve these problems, we combine the UKF as a tool for optimal state estimation with the numerical inverse kinematics. Combining the solution of the numerical inverse kinematics with the sampling based UKF provides the stability and rapid convergence to optimal estimate. In order to estimate the human pose, we extract the interesting human body using both background subtraction and skin color detection algorithm. We localize its 3D position with the camera geometry. Next, through we use the UKF based numerical inverse kinematics, we generate the intermediate joints that are not detect from the images. Proposed method complements the defect of numerical inverse kinematics such as a computational complexity and an accuracy of estimation.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.137-146
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• 2008

The purpose of this study is to examine the causes of errors from EGR posture on the balance beam, which is bending flick-flack salto backward stretched national team players through kinematic analysis, and present training methods for them so as to provide scientifically useful information to coaches and athlete. Findings from this study are summarized below. The most important factors that affect the errors in boyd center position and speed change were the speed change of left and right body centers and the horizontal and vertical speed changes. The left and right acceleration changes were greater in failed posture than in successful posture. The horizontal and vertical accelerations in E3 and E5 were the key factors that affected the backward somersault and landing. The angular speed changes which varied between success and failure were notable in head and shoulder joints. In individual results. The section when the angular speeds of head and shoulder joint must be the greatest was E4. In this section, when the body is extending instantly in a bent posture, increasing the angular speeds of head, shoulder and hip joints can improve the duration of staying in the air and the rotation radius of a somersault.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.2
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• pp.285-294
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• 1991

The human temporomandibular joint as a ginglymoarthrodial one has much in common with the other synovial joints of the body, but it does possess an unique charachteristic in that it must accomodate the various occlusal relations of dentition during an end point of closure. For that reason, the movement of the condyle in the temporomandibular joint is susceptible to influences from the nature of occlusion. Undue loading to the temporomandibular joint can be applied on the occasion of premature contacts in centric relation, balancing side interferences, change of occlusal surfaces due to excessive attrition, loss of tooth. Such occlusal disharmonies in association with the systemic and emotional factors may give rise to the temporomandibular disorder. On the other hand, the changes of occlusal patterns in the growing body can also have an effect on the growth of the temporomandibular joint through the alterations of functional stresses. The purpose of this study was to observe histopathologic response of the temporomandibular joint in unilateral chewing on one side exclusively for 10 months. Three dogs showing normal masticatory function were chosen. One dog aged about 12 months was for control, two dogs for experimental specimens were about 12 and 18 months old respectively. For chewing on the left side only, unilateral lower right premolar and molar were extracted in two experimental specimens. And then three dogs were sacrificed 10 months later. Frontal histologic sectioning of joints were done for the observation of the effects of one-side chewing. 24 specimens from three dogs were obtained and fixed in 10% formalin and routinly processed with H-E staining for histologic examination. The light microscopic findings were interpretated as follows: 1. Experimental specimen 1 aged about 22 months: In comparison with control and right non-chewing side, the proliferative and hypertrophic zone were increased at the mesial and lateral part of left chewing side condyle. There was no change of the articular tissue of temporal bone. 2. Experimental specimen 2 aged about 28 months: The articular tissues of adult joint were observed. The differences between the chewing and non-chewing side were not seen in the articular tissues of condyle and temporal bone.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.29-29
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• 2009

On this research, laser welding technology for manufacturing automobile body is studied. Laser welding technology is one of the important technologies used in the manufacturing of lighter, safer automotive bodies at a high level of productivity; the leading automotive manufacturers have replaced spot welding with laser welding in the process of car body assembly. Korean auto manufacturers are developing and applying the laser welding technology using a high output power Nd:YAG laser and a 6-axes industrial robot. On the other hand, the robot-based remote laser welding system was equipped with a long focal laser scanner system in robotic end effect. Laser system, robot system, and scanner system are used for realizing the high speed laser welding system. The remote laser welding system and industrial robotic system are used to consist of robot-based remote laser welding system. The robot-based remote laser welding system is flexible and able to improve laser welding speed compared with traditional welding as spot welding and laser welding. The robot-based remote laser systems used in this study were Trumpf's 4kW Nd:YAG laser (HL4006D) and IPG's 1.6kW Fiber laser (YLR-1600), while the robot systems were of ABB's IRB6400R (payload:120kg) and Hyundai Heavy Industry's HX130-02 (payload:130kg). In addition, a study of quality evaluation and monitoring technology for the remote laser welding was conducted. The welding joints of steel plate and steel plate coated with zinc were butt and lapped joints. The quality testing of the laser welding was conducted by observing the shape of the beads on the plate and the cross-section of the welded parts, analyzing the results of mechanical tension test, and monitoring the plasma intensity and temperature by using UV and IR detectors. Over the past years, Trumf's 4kW Nd:YAG laser and ABB's IRB6400R robot system was used. Nowadays, the new laser source, robot and laser scanner system are used to increase the processing speed and to improve the efficiency of processes. This paper proposes the robot-based remote laser welding system as a means of resolving the limited welding speed and accuracy of conventional laser welding systems.

• Journal of Korean Medicine Rehabilitation
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• v.18 no.2
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• pp.17-31
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• 2008

Objectives : This study was carried out to investigate the effects of Samgi-eum($S{\bar{a}}nq{\grave{i}}-y{\check{i}}n$) on the monosodium iodoacetate-induced osteoarthritis in rats. Methods : Osteoarthritis was induced by injection of monosodium iodoacetate intraarticularly in both knee joints. Arthritic rats were divided into control and treated group. Control group were taken distilled water for 20days. Treated group were taken extracts of Samgi-eum($S{\bar{a}}nq{\grave{i}}-y{\check{i}}n$) by orally for the same duration. Normal group were injected normal saline and taken distilled water. Body weights were measured at 0, 5th, 10th, 15th, 20th day after injection. At the end of the experiment, gross and histopathological examination on the articular cartilages of the knee joints were performed. Proteoglycan contents of articular cartilages were analyzed by safranine O staining method. The contents of $TNF-{\alpha}$, $IL-1{\beta}$ and IL-6 in synovial fluids were analyzed by ELISA method. Results : 1. Body weights of the treated group were significantly increased compared with control at 20days after injection. 2. Grossly, the severity of osteoarthritis in the treated group were alleviated compared with control. 3. Histopathologically, degenerative and necrotic lesion of articular cartilages in the treated group were alleviated compared with those of the control and histopathological scores of treated group were significantly decreased compared with control. 4. PG contents in articular cartilages of the treated group were significantly increased compared with control. 5. $TNF-{\alpha}$ contents in synovial fluids of the treated group were significantly decreased compared with control. Conclusions : According to above results, Samgi-eum($S{\bar{a}}nq{\grave{i}}-y{\check{i}}n$) has anti-arthritic effects on the monosodium iodoacetate-induced osteoarthritis in rats. And it is related with reduced secretion of $TNF-{\alpha}$ from osteoarthritic chondrocytes and synovial membranes.

• Journal of Conservation Science
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• v.17 s.17
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• pp.83-94
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• 2005

Host rock or the standing sculptured Buddha in the Yongamsa temple is macular porphyritic biotite granite, which has gone through mechanical and chemical weathering. The rock around the Buddha statue is busily scattered with steep inclinations that are almost vertically discontinuous planes with the strikes of $N8^{\circ}E$. Especially the development of the joints that cross the major joints causes the structural instability of the rock. The rock of the Buddha statue is separated into several rock blocks because of many different discontinuity. Thus it is estimated that the bed rock has not only plane and toppling failure but also wedge failure in all the sides. Since the differential pressure is imposed on the body of the Buddha in the host rock, it is urgent to give a reinforce treatment of geotechnical engineering for the safe of its structural stability. Very contact area of joints have turned into soil, which promotes the growth of weeds and plant roots, then aggravates the mechanical weathering of the rock. Thus conservational treatments should also be considered to get rid of secondary contaminants and vegetation along the discontinuities and to prevent further damages.

• The Journal of Korean Academy of Prosthodontics
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• v.20 no.1
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• pp.51-66
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• 1982

The purpose of this study was primarily to determine the relationship between temporomandibular joint mobility and generalized benign joint hypermobility. The subjects were 85 men and 76 women, who were students of dental and dental hygiene schools, aged 18 to 30 years old. They had no disturbances or complaints of movement of temporomandibular joints and other joints in the body. The joint mobility was measured by a test which is a modification of a method developed originally by Carter and Wilkinson (1964). The mandibular mobility was measured during active and passive maximal opening, laterotrusion, protrusion, and retrusion by Ingervall's method (1970). The obtained results were as follows: 1. The distribution of joint hypermobility disclosed was 4.8% in men and 19.7% in women, and 11.8% of total subjects. 2. The joint mobility index was a mean of 0.37 for men and 0.51 for women in total subjects, and 0.80 for men and 0.73 for women in hypermobile subjects. 3. The angle of passive dorsiflexion of the little finger was greater in the left than in the right hand for both sexes and in hypermobile subjects than in total subjects. 4. There was a positive correlation between the joint mobility index and the angle of passive dorsiflexion of the little finger in total subjects. 5. The joint mobility was greater in women than in men, and in the left than in the right hand. 6. In the active maximal mandibular movements of total subjects, the mean values for the opening capacity was 56.01 mm and 52.04mm, the laterotrusion mean 8.07 and 8.08, the protrusion mean 8.72 and 8.24, and the retrusion mean 0.48 and 0.49 for men and women respectively. 7. In the passive maximal mandibular movements of total subjects, the mean values for the opening capacity was 59.07mm and 54.85mm, the laterotrusion mean 8.90 and 9.12, the protrusion mean 10.03 and 10.00, and the retrusion mean 0.69 and 0.72 in men and women respectively. The active and passive maximal opening capacity was larger in men than in women but in the other movements there were no significant differences between men and women. 8. The range of active and passive maximal mandibular movements of hypermobile subjects tended to be larger in men but no significant difference in women compared with that of total subjects. 9. The range of maximal mandibular movements was increased more in passive than in active.

• Journal of Welding and Joining
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• v.34 no.2
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• pp.1-10
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• 2016

The use of materials for modern lightweight auto-bodies is becoming more complex than hitherto assemblies. The high strength materials nowadays frequently used for more specific fields such as the front and rear sub frames, seat belts and seats are mounted to the assembled body structure using bolt joints. It is desirable to use nuts attached to the assembled sheets by projection welding to decrease the number of loose parts which improves the quality. In this study, nut projection welding was carried out between a nut of both boron steel and carbon steel and ultra-high strength hot-stamped steel sheets. Then, the joints were characterized by optical and scanning electron microscope. The mechanical properties of the joints were evaluated by microhardness measurements and pullout tests. An indigenously designed sample fixture set-up was used for the pull-out tests to induce a tensile load in the weld. The fractography analysis revealed the dominant interfacial fracture between boron steel nut weld which is related to the shrinkage cavity and small size fusion zone. A non-interfacial fracture was observed in carbon steel nut weld, the lower hardness of HAZ caused the initiation of failure and allowed the pull-out failure which have higher in tensile strengths and superior weldability. Hence, the fracture load and failure mode characteristics can be considered as an indication of the weldability of materials in nut projection welding.

• The Korean Journal of Nuclear Medicine
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• v.36 no.4
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• pp.255-260
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• 2002

Purpose: SAPHO syndrome is well known to various disease entities including synovitis, acne, pustulosis, hyperostosis and polyarthritis. The purpose of this study is to evaluate sicntigraphic findings and to compare with radiologic findings in SAPHO syndrome. Materials and Methods: Five patients (M:F=5.0, Age $22.8{\pm}4.78$ yrs) with SAPHO syndrome were enrolled in our study. All patients underwent whole-body bone scintigraphy with intravenous administration of 740 MBq of Tc-99m MDP. Among them, two patients were additionally perfomed SPECT of the spine to evaluate the location and extort of spinal lesion. Results: All patients were demonstrated abnormal increased uptakes in sternoclavicular joint (SC), sacroiliac joint (SI), and small joints of both hands. Among them, three patients were bilateral involvement (3/5) and two were unilateral (2/5) in SC. involvement of SI showed bilateral in four patients (4/5) and unilateral in one (1/5). SPECT images demonstrate that the lesion sites of the lumbar spine are more likely facet joints than vertebral bodies or pedicles. Conclusion: As SAPHO syndrome is the disease entity involved polyarticular joints with various dermatologic manifestations, the bone scintigraphy may be a very useful method to evaluate the location and extent of joint involvement, and to avoid inadequate surgical management or ineffective antibiotic treatment.

• Transactions of the KSME C: Technology and Education
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• v.3 no.2
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• pp.131-140
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• 2015

The mono-ski for the paraplegia designed to skiing is formed as seat bucket on the sled. The impact force transferred by snow surface during skiing is absorbed by the leg joints of normal human, but it is transferred to the human body on the seat when using mono-ski. Most of commercially available mono-ski have absorbing device and link mechanism between seat and ski mount in order to complement it. In this study we developed the comfort evaluation model that could provide skiing simulation of mono-ski with hydraulic damper and analyzed vibrational acceleration occurred during skiing uneven surface. The evaluation method used in this study is the international standard BS6841. We evaluated comfort performance of mono-ski in accordance with nozzle adjustment of hydraulic damper.