• Journal of Korean Neurosurgical Society
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• v.46 no.1
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• pp.1-4
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• 2009

Objective: To report an unsuspected adaptive plasticity of single upper motor neurons and of primary motor cortex found after microsurgical connection of the spinal cord with peripheral nerve via grafts in paraplegics and focussed discussion of the reviewed literature. Methods: The research aimed at making paraplegics walk again, after 20 years of experimental surgery in animals. Amongst other things, animal experiments demonstrated the alteration of the motor endplates receptors from cholinergic to glutamatergic induced by connection with upper motor neurons. The same paradigm was successfully performed in paraplegic humans. The nerve grafts were put into the ventral-lateral spinal tract randomly, with out possibility of choosing the axons coming from different areas of the motor cortex. Results: The patient became able to selectively activate the re-innervated muscles she wanted without concurrent activities of other muscles connected with the same cortical areas. Conclusion: Authors believe that unlike in nerve or tendon transfers, where the whole cortical area corresponding to the transfer changes its function a phenomenon that we call "brain plasticity by areas". in our paradigm due to the direct connection of upper motor neurons with different peripheral nerves and muscles via nerve grafts motor learning occurs based on adaptive neuronal plasticity so that simultaneous contractions of other muscles are prevented. We propose to call it adaptive functional "plasticity by single neurons". We speculate that this phenomenon is due to the simultaneous activation of neurons spread in different cortical areas for a given specific movement, whilst the other neurons of the same areas connected with peripheral nerves of different muscles are not activated at the same time. Why different neurons of the same area fire at different times according to different voluntary demands remains to be discovered. We are committed to solve this enigma hereafter.

• Journal of Korean Physical Therapy Science
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• v.18 no.2
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• pp.73-80
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• 2011

Purpose: The purpose of this study was to investigate the correlation between the visual perception ability and the static dynamic balance ability in health elderly. Method: The Motor Free Visual Perception Test-Row Score(MVPT-RS) and MVPT-Process Time(MVPT-PT) were used for evaluating the visual perception abilities. Assessment of the balance ability was taken by using Good Balance System. In the assessment using Good Balance System, X, Y coordinate speed, anterior-posterior direction, medial-lateral direction and Velocity Movement(VM) in standing posture when eye open were measured as static balance abilities. Thirty-seven healthy elderly who live in Gwangyang participated in the experiment for 2 months, from October to November 2010. Results: 1. There were statistically significant differences of MVPT-RS, MVPT-PT, NSB-X, NSB-Y, NSB-VM, OLB-X, and OLB-VM based on the gender(p<0.05). 2. The negative correlations of MVPT-RS:NSB-Y(r=-0.354), MVPT-RS:OLB-X(r=-0.4), MVPT-RS: OLB-Y(r=-0.371), but positive correlations of MVPT-PT:DTB-T showed a statistical significance(r=0.45, p<0.05). 3. The positive correlations of NSB-X:NSB-Y(r=0.54), NSB-X: NSB-VM(r=0.848), NSB-Y:NSB-VM(r=0.531), OLB-X:OLB-Y(r=0.876), OLB-X:OLB-VM(r=0.872), and OLB-Y:OLB-VM(r=0.787) showed statistical significances(p<0.05). Conclusion: These results showed that the visual perception ability was correlated with some balance ability in health elderly. Especially the perception test process time(MVPT-PT) has closely related with the DTB-T. The visual perception ability is considered as a factor on the balance ability in health elderly. Further study will focus on the development of improving program of visual perception ability as an improving method of balancing ability in health elderly.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.596-601
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• 2004

In this paper, we describe a study on the influence of the frequency variation of normal vibration using an integrated tactile display. It is necessary to consider this study because we want to find a method of displaying finer texture and know that the perception of fine textures is heavily influenced by temporal variation. Our tactile display system used in this experiment can simulate the micro shapes and roughness of surface textures by individual drives of a 6x8 pin array. Two experiments are performed. The first is a psychophysical experiment on the definition and range decision of roughness, and through the experiment, we clear up the meaning of roughness. The second is the main experiment about the frequency variation of normal vibration. We find the correlation between the vibration frequency and the texture and the condition for better display and perception of fine surfaces. The experimental results yielded two pieces of information. One is that lateral movement affects texture discrimination, and another is that normal vibration can make the perceived texture feel finer than real texture. That is, the vibrating stimulus is more effective for displaying a fine surface than static pressure, and it makes possible to display finer texture, exceeding the physical limit of the device.

• Journal of the Korean Geotechnical Society
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• v.36 no.11
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• pp.51-60
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• 2020

Estimation of passive earth pressure is an important factor in anchor block, temporary retaining wall and support block of raker that resist lateral earth pressure. In practice, due to ease of use, it is common to estimate the earth pressure using the theory of Coulomb and Rankine, which assumes the failure plane as a straight line. However, the passive failure plane generated by friction between the wall surface and the soil forms a complex failure plane: a curve near the wall and a flat plane near the ground surface. In addition, the limit displacement where passive earth pressure is generated is larger compared to where the active earth pressure is generated. Thus, it is essential to calculate the passive earth pressure that occurs at the allowable displacement range in order to apply the passive earth pressure to the design for structural stability reasons. This study analyzed the mobilized passive earth pressured to various displacement ranges within the passive limit displacement range using the semi-empirical method considering the complex failure plane.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.3
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• pp.288-297
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• 1999

This study has been carried out in order to measure the thickness of soft-tissue on lateral cephalographs based on body mass index(BMI) and the change in soft-tissue thickness after surgical correction of mandibular protrusion. The control material in cephalometric study comprised students at The Dental College, 38 persons, aged 21~24 years and the patient material comprised 20 women and 12men, aged 19~28 years with mandibular protrusion.The thickness of the soft-tissue based on BMI in control and study groups, the comparison between them, immediate postoperative change in the thickness, 6 months after surgery, ratio of soft-tissue response and correlation was established through various statistical methods. The result were as follows : 1. The groups based on BMI showed significant differences each other as regards the linear measurements. The thickest soft-tissue was measured 13.6mm, 15.47mm, 16.76mm at Ss, the thinnest at G' 6.0mm, 6.7mm, 7.26mm respectively. 2. The differences between control and experimental groups based on BMI showed to be significant. There were no differences at G'. The soft-tissue in prognathic patients was thicker at Ss, Ls and thinner at Li, Ls, Pg', Gn', Me'. Differential gap was greater in overweight groups. 3. The immediate soft-tissue change after surgery showed the increase at Li, Ls, Pg', Gn', Me' except G', Ls in all groups. 4. The postoperative soft-tissue change 6 months after surgery was similar with immediate change. The soft-tissue shows the increase in the thickness at Li, Pg', Gn', Me' and the greatest difference occurred at Li, 1.1mm, 0.98mm, 1.2mm respectively. 5. The patients with lower BMI index showed higher soft-tissue response to bony movement at Pg'. The immediate response ratio was 91%, 87%, 81% in A,B,C groups respectively, the response 6 months after surgery showed 96%, 91%, 84%.

• Physical Therapy Korea
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• v.24 no.3
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• pp.30-39
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• 2017

Background: Scapular posterior tilt (SPT) is important in the prevention of abnormal scapular movement and pain during elevation of the arm. However, previous studies have overlooked increased upper trapezius (UT) muscle activity interrupting the normal force couple of scapular motion and compensation of levator scapulae (LS) muscle activated simultaneously with UT during SPT exercise. Objects: The purpose of this study was to compare the effects of modified SPT with depression exercise versus SPT exercise on serratus anterior (SA), lower trapezius (LT), UT, and LS muscle activities and the clavicular tilt angle, in subjects with rounded shoulder posture (RSP) and myofascial pain in the UT muscle region. Methods: Eighteen subjects with RSP were recruited and randomly allocated to 2 groups; 9 in the SPT group and 9 in the SPT with depression group. All subjects met the specific RSP criteria and had myofascial pain of UT region. Depending on the allocated group, subjects performed the assigned SPT exercise and EMG data were recorded during the each exercise. Clavicular tilt angle was defined as the angle between the line joining the medial and lateral end of the clavicle and a horizontal line. Results: The SA muscle activity was significantly greater in SPT with depression than with SPT exercise (p<.05). The UT, LS muscle activity and the clavicular tilt angle was significantly lower in SPT with depression than with SPT exercise (p<.05). Conclusion: These findings were insightful because the potential risk of pain from overactivation of the UT and LS was considered, in contrast with SPT exercise. SPT with depression exercise can be implemented as an effective method to facilitate scapular muscle activity for stability and to prevent myofascial pain in the neck and shoulder.

• Journal of Embryo Transfer
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• v.31 no.3
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• pp.287-291
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• 2016

For evaluating the boar semen quality, sperm motility (MOT) is an important parameter because the movement of spermatozoa indicates active metabolism, membrane integrity and fertilizing capacity. Estrogen receptors 2(ESR2) is involved in estrogen related apoptosis in cell cycle spermatogenesis, but their functions have not been confirmed in pig until now. Therefore, this study was conducted to analyze their association with sperm motility and kinematic characteristics. DNA samples from 105 Duroc pigs with records of semen motility and kinematic characteristics [Total motile spermatozoa (MOT), Curvilinear velocity(VCL), Straight-line velocity(VSL), the ratio between VSL and VCL(LIN), Amplitude of Lateral Head displacement(ALH)] were analyzed. A SNP in coding region of ESR2 g.35547A > G in exon 5 was associated with MOT (p < 0.05) in Duroc population. Therefore, we suggest that the porcine ESR2 gene may be used as a molecular marker for Duroc boar semen quality, although its functional effects were not defined yet. These results might shed new light on the roles of ESR2 in spermatogenesis as candidate gene for boar fertility, but still the lack of association across populations should be considered.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.1
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• pp.38-43
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• 1999

Tooth transposition is the phenomenon in which two teeth in the dental arch are exchanged. The tooth most frequently involved in transposition is the permanent maxillary canine, especially with the first premolar. The etiology of transposition is still an enigma. Interchange of tooth germs, migration during eruption, genetic factor, local pathologic factors may be suggested as possible etiologic factors. There are three main options for treatment, which are the extraction of one of the transposed teeth, the alignment in the transposed position, the orthodontic movement of the teeth to their correct positions. If complete transposition occurred especially in mandible, alignment of teeth in the transposed position followed by occlusal reduction and esthetic restoration is usually recommended. The presented two-case report will describe the maxillary canine to the first premolar and to lateral incisor transposition with associated peg lateralis and retained primary canines. Although alignment the transposed teeth in original position is ideal treatment, it companies many complication as root resorption, alveolar bone destruction, gingival deheisence, etc. Therefore the treatment procedures in these case was relative cost-benefit effective method to both clinician and patients.

• The Korean Journal of Quaternary Research
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• v.18 no.2 s.23
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• pp.5-16
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• 2004

The geomorphic deformation of the alluvial fans by tectonic movement was investigated along the lineaments of the northem part of the Ulsan(Bulguksa) fault system. Based on the aerial photographs interpretation and field surveys Ulsan fault system was identified as an active reverse fault which has displaced the Quatemary fan deposits. Buguksa fault system strikes for the direction of NW-SE and N-S. These two lineaments of active fault are crossing at Jinty village in Gyeongju city and the fault plane forms here almost vertical dip. The lateral pressures from the two directions have possibly influenced on the formation of the vertical dip at jinty villagy. It should be resulted from that the two pressures responsible for the active reverse fault at which the one with the NW-SE strike thrusts the hanging wall of Tohamsan block southwestward and the other pressure with the N-S strike thrusts it westward over the foot wall of the fan deposits. The marine oxygen isotope stage 8(0.30-0.25 Ma. BP) and stage 6(0.20-0.14 Ma. BP) are presumed to be the ages of high and middle surfaces of the alluvial fan, repectively. The vertical displacements on the high surfaces along the Bulguksa fault system are about 1.05 m at Ha-Dong, 9.5-10.5 m at Jinhyun-Dong, and about 10 m high at Jinty village. And the vertical displacement on the middle surface was measured about 6 m high at Ha-Dong. The average slip rate of vertical displacements is calculated about 0.03-0.43 mm/y.

• Archives of Craniofacial Surgery
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• v.11 no.2
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• pp.77-84
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• 2010

Purpose: The nasal bones are the most common fracture sites of the facial bones, and a careful reduction may still result in secondary deformities, such as saddle nose, deviated nose, hump nose etc, requiring secondary cosmetic rhinoplasty. Therefore, this study examined the clinical characteristics of nasal bone fractures to propose guidelines for patient selection and surgical procedures to achieve more satisfactory results and to prevent secondary deformities with simultaneous augmentation rhinoplasty and bony reduction. Methods: The study was based on 26 out of 149 nasal bone fracture patients who underwent simultaneous augmentation rhinoplasty with bony reduction between May 2008 and April 2009. Retrospective analysis was performed according to the clinical data, surgical techniques and postoperative results. Results: Of the 26 patients, there were 15 males and 11 females. The incidence according to the Stranc's classification revealed that 62% of patients were injured by a frontal impact and 38% by a lateral impact. Frontal impact plane I (50%) was the most frequent type. At the follow up, 18 (81.2%) out of 22 patients were satisfied with their postoperative outcome, and the remaining 4 patients were fair. No one was dissatisfied. However, 5 cases in 3 patients (23%) had some complications; minimal implant deviation in 2 cases, minor irregularity on the nasal dorsum in 2 cases and palpable implant movement under palpation in 1 case. None of these cases required surgical correction. Conclusion: With the proper guidance, simultaneous augmentation rhinoplasty with bony reduction can prevent secondary deformities and satisfy the cosmetic outcomes.