• Korean Journal of Applied Biomechanics
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• v.25 no.3
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• pp.257-263
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• 2015

Objective : The purpose of this study was to investigate the effect of genu valgum on the body mass index, movement of lower limb joints, and ground reaction force. Methods : Gait patterns of 30 college students with genu valgum were analyzed and the static Q angle of the femur was measured for selecting genu valgum of the subjects. To analyze the kinetic changes during walking, the six-camera Vicon MX motion analysis system was used. The subjects were asked to walk 12 meters using the more comfortable walking method for walking. After they walked 12 meters more than 10 times, their most natural walking patterns were chosen three times and analyzed. Results : As a result of measuring a relationship between genu valgum and Q-angle, as the Q-angle increases, it showed a genu valgum also increased. Body Mass Index showed a significant difference between the groups was higher in the genu valgum group.(p<.001). The analysis result showed that genu valgum had a significant effect on the internal rotation moment in the hip joint(p<.05). Also, genu valgum had a significant effect on the internal rotation moment of the knee joint(p<.05). The comparative analysis of the Medial-Lateral ground reaction force in the genu valgum group showed a tendency to increase the medial ground reaction force(p<.05). The vertical ground reaction forces of the middle of the stance phase(Fz0) showed a significant increase in genu valgum group(p<.05), in particular the results showed a decrease in the early stance phase(p<.001). Conclusion : In conclusion, the change in body mass is considered to be made by proactive regular exercise for improvement of the genu valgum. In addition, the prevention of the deformation caused by secondary of the genu valgum in this study may be used as an indicator of the position alignment rehabilitation for structural and functional improvements. Applying a therapeutic exercise program for the next lap will require changes in posture alignment.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.8
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• pp.839-847
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• 2012

Numerical simulations for channel flows with $Re_{\tau}$ = 180, 395 and 590 have been performed to investigate the hairpin packet formation process in wall-bounded turbulent flows. Using direct numerical simulation databases, the initial flow fields are given by the conditionally averaged flow field with the second quadrant event specified at the buffer layer. By tracking the initial vortex development, the change in the initial vortex to an ${\Omega}$-shaped vortex and th generation of a secondary hairpin vortex were found to occur with time scales based on the wall units. In addition, at the time when the initial vortex has grown to the channel center, the inclination angle of the hairpin vortex packet is approximately $12{\sim}14^{\circ}$, which is similar for all three Reynolds numbers. Finally, numerical simulations of the evolution of two adjacent hairpin vortices have been performed to examine the interaction between the adjacent vortex packets.

• Journal of Korean Foot and Ankle Society
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• v.23 no.3
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• pp.110-115
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• 2019

Purpose: This study analyzed the clinical and radiological results of Reudi-Allgower type II and III open tibia pilon fracture patients who underwent plate fixation after the recovery of a soft tissue injury after external fixation. Materials and Methods: From 2010 to 2015, this study analyzed 14 patients who were treated for open tibial pilon fractures and could be followed up at least one year. The mean age was 49 years and the average follow-up period was 19 months. An emergency operation was performed for external fixation and open wounds, and secondary surgery was performed for definitive fixation using a plate. The radiological and clinical evaluations were analyzed retrospectively. Complications, such as post-traumatic osteoarthritis and wound infections were also analyzed. Results: The mean duration between two-staged surgery was 21 days and the mean bone union time was 9.2 months. Three cases of delayed union and one case of nonunion were reported. The malunion did not occur in all cases. The average American Orthopaedic Foot and Ankle Society (AOFAS) score was 68 points. A limitation of the ankle motion occurred in all cases. In four cases, wound infections due to initial open wounds occurred; one patient underwent a below the knee amputation due to chronic osteomyelitis. Post-traumatic arthritis occurred in 10 cases. Conclusion: Severe comminuted tibial plateau open fractures of Reudi-Allgower type II and III, which are high-energy injuries that result in extensive soft tissue damage, have a higher incidence of complications, such as ulcer problems and osteomyelitis, than closed tibia plateau fractures. Post-traumatic arthritis is the most common complication of tibia plateau open fractures, and staged surgery is recommended because of the relatively satisfactory clinical results.

• Clinics in Shoulder and Elbow
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• v.18 no.1
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• pp.28-35
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• 2015

Background: We assessed the effectiveness of arthroscopic capsular release for the treatment of adhesive capsulitis. Further, we tried to ascertain the clinical benefits, if any, of pancapsular release over selective capsular release, where the two differ by performing or not performing a posterior capsular release, respectively. Methods: Thirty-five consecutive patients with either primary or secondary adhesive capsulitis who failed conservative treatment for more than 6 months were enrolled in the study. A total of 16 patients allocated in group 1 received a pancapsular release that comprises the release of the rotator interval, anteroinferior capsular, and the posterior capsular release, whereas 19 patients in group 2 received a selective capsular release that comprises only the release of the rotator interval release and anteroinferior capsular release. The clinical outcomes, visual analogue scale (VAS) score, Constant score, and range of motion, were assessed preoperative and postoperatively. Results: In both groups, the preoperative VAS score, Constant score, and ROM showed a significant improvement by the 6-month follow-up. We found that the immediate postoperative internal rotation was significantly higher in group 1 than group 2. Despite significant differences seen between the two groups at the initial postoperative period, there were no significant differences in Constant score, VAS score, and the ROM at all the subsequent follow-ups between the two groups. Conclusions: Arthroscopic capsular release for the treatment of adhesive capsulitis is very effective. However, pancapsular release did not show any advantage over selective capsular release in terms of overall clinical outcome.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.174-174
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• 2009

The acromioclavicular-hook-plate is one of the surgical treatments for distal clavicle fracture and traumatic acromioclavicular (AC) joint dislocation. Although this procedure can obtain rigid and accurate anatomical reduction of the AC joint, secondary widening of the hook-hole in the acromion is often seen during postoperative follow-up. This complication is owing to the high-degree of mobility of the AC joint. Therefore, it is important to evaluate the effect on these complications due to the position of the hook-hole. The purpose of the present study is to investigate three-dimensionally the effect due to the position of the hook-hole during arm abduction motion. We studied in vivo and three-dimensional kinematics of the normal shoulder joint with use of a markerless bone-registration technique. Magnetic resonance images of 14 shoulders of 7 healthy volunteers were acquired in 7 positions between $0^{\circ}$ and $180^{\circ}$ of abduction. We created three-dimensional computer models of the bones and the acromioclavicular-hook-plate. Based on the three-dimensional kinematics data, we simulated the widening of the hook-hole each different positioning of the hook-hole. The widths of the hook-holes almost linearly increased. And these widths significantly increased, when we put the hook-hole on the acromion from AC joint to 20 mm and 25 mm posterior position.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.2
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• pp.116-120
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• 2012

The buccal fat pad is specialized fat tissue located anterior to the masseter muscle and deep to the buccinator muscle. Possessing a central body and four processes it provides separation allowing gliding motion between muscles, protects the neurovascular bundles from injuries, and maintains facial convexity. Because of its many advantageous functions, the use of the buccal fat pad during oral and maxillofacial procedures is promoted for the reconstruction of defects secondary to tumor resection, and those defects resulting from oroantral fistula caused by dento-alveolar surgery or trauma. We used the pedicled buccal fat pad in the reconstruction of intraoral defects such as oroantral fistula, maxillary posterior bone loss, or defects resulting from tumor resection. Epithelization of the fat tissue began 1 week after the surgery and demonstrated stable healing without complications over a long-term period. Thus, we highly recommend the use of this procedure.

• Journal of Magnetics
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• v.21 no.1
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• pp.12-19
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• 2016

The <100> oriented $Fe_{83}Ga_{17}$ alloys with various contents of NbC or B were prepared by directionally solidification method at the growth rate of $720mm{\cdot}h^{-1}$. With a small amount of precipitates, the columnar grains grew with cellular mode during directional solidification process, while like-dendrite mode of grains growth was observed in the alloys with higher contents of 0.5 at% due to the dragging effect of precipitates on the boundaries. The NbC precipitates disperse both inside grains and along the boundaries of $Fe_{83}Ga_{17}$ alloys with NbC addition, and the Fe2B secondary phase particles preferentially distribute along the grain boundaries in B-doped alloys. Precipitates could affect grain growth and improved the <100> orientation during directional solidification process. Small amount of precipitate element addition slightly increased the magnetostrictive strain, and a high value of 335 ppm under pre-stress of 15 MPa was achieved in the alloys with 0.1 at% NbC. Despite the fact that the effect on magnetic induction density of small amount of precipitates could be negligible, the coercivity markedly increased with addition of precipitate element for $Fe_{83}Ga_{17}$ alloy due to the retarded domain motion resulted by precipitates.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.12 no.1
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• pp.13-27
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• 2017

Objectives: To evaluate and summarize the efficacy and safety of manual therapy in temporomandibular disorder(TMD). Methods: Ten databases (Pubmed, Cochrane, EMBASE, AMED, CINAHL, CNKI, and four Korean databases) were searched up to March 2017. Pain and range of motion(ROM) of temporomandibular joint were used as the primary outcome measure, and effective rates, dysfunction scale and adverse events were used as secondary outcome measures. The Cochrane risk of bias tool was used to evaluate the methodological quality. Results: 10 randomized controlled trials(RCTs) involving 603 participants were included. There were no significant differences between the two groups in comparison with placebo manual therapy group. In comparison with Wait-list and conventional treatment groups, manual therapy significantly alleviated pain and ROM. Five RCTs(50.0%) reported adverse events and there were no adverse cases by manual therapy. Conclusions: We found evidence that manual therapy may alleviate symptoms of patients with TMD. A positive effect was observed in comparison with conventional treatment and Wait-list, but no conclusion for the comparisons with placebo manual therapy. There is no evidence of worsening symptoms or causing adverse events.

• Particle and aerosol research
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• v.9 no.2
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• pp.103-110
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• 2013

The electrostatic precipitator (ESP) has been used for degrading atmospheric pollutants. These devices induce the electrical forces to facilitate the removal of particulate pollutants. The ions travel from the high voltage electrode to the grounded electrode by Coulomb force induced by the electric field when a high voltage is applied between two electrodes. The ions collide with gas molecules and exchange momentum with each other thus inducing fluid motion, electrohydrodynamic (EHD) flow. In this study, for the simulation of electric field and EHD flow in ESPs, an open source EHD solver, "espFoam", has been developed using open source CFD toolbox, OpenFOAM(R) (Open Field Operation and Manipulation). The electric potential distribution and ionic space charge density distribution were obtained with the developed solver, and validated with experimental results in the literature. The comparison results showed good agreement. Turbulence model is also incorporated to simulate turbulent flow; hence the developed solver can analyze laminar and turbulent flow. In distributions of electric potential and space charge, the distributions become distorted and asymmetric as the flow velocity increases. The effect of electrical drift flow was investigated for different flow velocities and the secondary flow in a flow of low velocity is successfully predicted.

• School Mathematics
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• v.18 no.2
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• pp.349-373
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• 2016

Comparison of curriculum between various countries is a major research method for studying a course and content quoted on Korea's national curriculum. Therefore this research focuses on comparing and analyzing a new curriculum which Australia has announced on 2012 and conducting since 2015. From this research result, we found that Australia's curriculum achievement shows some unique characteristics. Such examples can be dealing a concept with real life context and proposing a mathematical content specifically. Also they introduce the definite integral by defining to the sum of series. There are other characteristics such as modelling motion, and numerical integration which Korea's highschool curriculum achievement doesn't deal with, and the content of vector calculus is handled more deeply. As a result of analyzing Australia's textbook, it fully deals with the supplementary notion to help understand mathematical definition. Hence further research will be needed later on to relieve the aspect of cognitive burden on Korean learners.