• Ocean and Polar Research
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• 제36권4호
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• pp.465-473
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• 2014

This paper proposes a formation control method by which multi-mining robots maintain a specified formation and follow a path. To secure the path tracking performance, a pure-pursuit algorithm is considered for each individual robot, and to minimize the deviation from the reference path, speed reduction in the steering motion is added. For the formation, in which two robots are parallel in a lateral direction, the robots track the specified path at a constant distance. In this way, the Leader-Follower method is adopted and the following robot knows the position and heading angle of the leader robot. Through the experimental test using two ground vehicle models, the performance is verified.

• The Journal of Korean Physical Therapy
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• 제14권3호
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• pp.24-44
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• 2002

Traction has been used since ancient times in the treatment of painfull spinal conditions, but the literature on traction and its clinical effectiveness Is limited. Traction can be defined as a drawing or pulling tension applied to a body segment. Cervical traction is a technique that applies a longitudinal force of the cervical spine and associated structures. Goals of traction include reduction of radicular signs and symptoms associated with conditions such as disk protrusion, degenerative disk disease, lateral stenosis, muscle spasm, and subluxations. The various mechanical factors most relevant to cervical traction are organized and discussed. The factors presented are 1) angle of pull, 2) Traction force, 3) duration of traction, 4) neck position and clinical application, and 5) frequency of treatment. It should allow physical therapists to adjust traction protocol to match the patient's symptoms and diagnosis. The purpose of this study is to provide a comprehensive overview of the cervical traction and treatment guidelines.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권3호
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• pp.138-144
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• 2000

The detent force caused by the interaction of magnets with the teeth of a armature core deteriorates the driving performance of a permanent magnet linear synchronous motor. In this paper, we analyze the fields and forces of a linear synchronous motor with segmented or skewed magnet arrangement according to lateral overhang length of permanent magnets. For the analysis, the 3-dimensional equivalent magnetic circuit network method is used. The detent force and the static thrust are analyzed according to the segmented or skewed angle and the overhang length of permanent magnets, and the optimal angles that the detent force is minimized are found out in each case. The analysis results are compared with the experimental ones and shown a reasonable agreement.

• Wind and Structures
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• 제16권2호
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• pp.213-224
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• 2013

One of the key issues affecting the promotion of solar water heaters in Taiwan is the severe impact of typhoon each year. An experimental study was conducted to investigate the wind uplift characteristic of a solar collector model with and without a guide plate. The guide plate with different lengths and orientations with respect to wind direction was adopted. It is found that the wind uplift of a solar collector is associated with the tilt angle of the flat panel as expected. A cavity formed between the guide plate and the flat panel has a significant effect on the distributions of streamwsie and lateral pressure. Reduction in uplift is essentially coupled with the projected area of a guide plate on the lower surface of the tilt flat panel.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권6호
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• pp.490-496
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• 2011

Purpose: Dr. Marquardt made the facial 'phi' mask using golden ratio. Most class III patients have bulky faces and want a smaller face. Using a facial golden mask, this study estimated and compared frontal photographs before and after operation for soft tissue measurement. The golden mask can be considered as a reference tool for facial esthetic analyses especially in lower face. Methods: Forty patients who had undergone orthognathic surgery at Samsung Medical Center from January 2006 to December 2009 were included in this study. These patients had Class III malocclusion. Lateral cephalometric radiographs, frontal clinical photos of pre-op and 8~12 month later post-op, and the facial 'phi' mask using golden ratio, were used for analysis. Reduction of the lower face area, occlusal plane changes, amounts of mandible setback and amounts of maxilla posterior impaction were estimated. Results: Lower facial reduction ratio and mandibular setback amounts were significantly different between 1-jaw and 2-jaw groups. Average postoperative changes in the area of lower face between bilateral sagittal split ramus osteotomy (BSSRO) and BSSRO combined maxilla posterior impaction were compared by using an independent simple t-test and $P$ value was 0.016. Therefore, the lower facial reduction ratio and mandibular setback amount were significantly different in maxilla posterior impaction. Conclusion: The two-jaw surgery group showed more reduction of the lower facial area than the 1-jaw surgery group. The amount of lower facial reduction was more related with the amount of mandibular setback. There was no significant relation in lower facial reduction with amount of maxilla posterior impaction, pre-op occlusal plane, post-op occlusal plane and the mandibular angle. A relationship between the change in the lower facial area and the amount of maxilla posterior impaction or the change of mandibular angle occlusal plane at pre-op could not be found because of the difference in the amount of setback between two groups.

• 대한족부족관절학회지
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• 제20권1호
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• pp.27-31
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• 2016

Purpose: Several techniques have been introduced for correction of pes cavo-varus deformity. We retrospectively reviewed and compared the data of patients who underwent 1st metatarsal osteotomy alone, Dwyer's osteotomy alone, and 1st metatarsal osteotomy combined with Dwyer's osteotomy to determine the effect on radiographic parameters. Materials and Methods: Data on 28 cases in 27 consecutive patients recruited from 2006 to 2014 who underwent 1st metatarsal osteotomy alone (group F), Dwyer's osteotomy alone (group H), or 1st metatarsal osteotomy followed by Dwyer's osteotomy (group HF) with a minimum 1-year follow-up were reviewed retrospectively. Results: Calcaneal pitch angle on the standing foot lateral radiographs was significantly decreased after the operation in groups H and HF whereas Meary angle was decreased in groups F and HF. Hindfoot alignment angle and ratio on the hindfoot alignment view were improved in groups H and HF. Maximal medial cuneiform height reduction was observed in group HF. 1st ray was significantly shortened in groups F and HF. Conclusion: Combined forefoot and hindfoot operation took the largest correction power of all radiologic parameters.

• 치위생과학회지
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• 제23권2호
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• pp.112-122
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• 2023

Background: This study aimed to evaluate the effect of a prefabricated functional appliance (Myobrace^®) on skeletal, dental, and soft tissue components in children with Class II, division 1 malocclusion. Methods: Thirteen patients with Class II, division 1 malocclusion (9 girls and 4 boys; mean age, 8.2±0.9 years at the start and 9.3±1.0 years at the end of the treatment) were treated with Myobrace^® for a mean period of 12.9±4.0 months. Patients were instructed to use the appliance daily for 1 hour and overnight while sleeping. A control group of 10 patients with untreated Class II, division 1 malocclusion (3 girls and 7 boys; mean age, 9.0±1.6 years at the start and 10.4±2.1 years at the end of the observation) was included to eliminate possible growth effects. The mean observation period for this group was 17.7±11.2 months. Lateral cephalograms were taken at the start and end of the treatment, and findings from 41 measurements were analyzed using the V-Ceph^TM program. The mean and standard deviation of cephalometric measurements were analyzed using paired and independent sample t-tests. Results: The treatment group showed significant changes in SNB, ANB, maxillary protrusion, ramus height, proclination of upper anterior teeth, interincisal angle, overjet, and upper lip protrusion compared with the control group. However, only decrease in ANB, maxillary protrusion, overjet, upper lip protrusion, and increase in interincisal angle were significantly higher in the treatment group than in the control group. Conclusion: The prefabricated functional appliance induced skeletal, dentoalveolar, and soft tissue changes, resulting in a significant reduction in anteroposterior discrepancy.

• PNF and Movement
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• 제20권2호
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• pp.189-201
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• 2022

Purpose: The purpose of this study was to investigate the effect of McConnell taping and Kinesio taping on pain and lower extremity joint angles when patients with patellofemoral pain syndrome (PFPS) ascend stairs. Methods: Fifty young adults who were experiencing anterior knee pain due to PFPS were selected as participants. Then, 25 patients were randomly assigned to the McConnell taping group and 25 to the Kinesio taping group. Pain and lower extremity joint angle were measured while ascending stairs before and after the intervention. A paired t-test was performed to evaluate the amount of change in the parameter values after the intervention within the groups, and an independent t-test was used to compare the results of the groups. Results: In the within-group comparisons, a statistically significant difference was found in both groups between the anterior knee pain scale scores recorded before and after the intervention (p < 0.05). A statistically significant difference was also found between the groups (p < 0.05). Comparison of the lower extremity joint angles at initial contact, loading response, terminal stance, and pre-swing within the groups showed that there were statistically significant differences in the hip, knee flexion, abduction, lateral rotation, and dorsiflexion angles in both the McConnell and Kinesio taping groups (p < 0.05). There was also a statistically significant difference in all angles between the groups during the following events (p < 0.05): (1) at initial contact, (2) at loading response (except hip flexion angle), (3) at terminal stance (except hip flexion and lateral rotation angles), and (4) at pre-swing (except hip, knee abduction, and inversion angles). Conclusion: McConnell taping and Kinesio taping both effectively improved the occurrence of knee pain and the lower extremity joint angles during stair ascent in patients with PFPS. However, McConnell taping had a significant impact on pain reduction and lower extremity joint angles compared to Kinesio taping.

• Journal of Oral Medicine and Pain
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• 제36권1호
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• pp.39-51
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• 2011

본 연구는 측두하악장애의 연구 진단 기준(Research Diagnostic Criteria for Temporomandibular Disorder; RDC/TMD)을 이용하여 구분된 측두하악장애(Temporomandibular Disorder; TMD) 환자를 대상으로 안면의 골격적 양상과 TMD 사이의 연관성을 규명하고 교정 환자의 진단과 치료에 있어 RDC/TMD의 활용 가능성을 제시하고자 하였다. 서울대학교 치과병원 구강내과에 측두하악장애의 진단과 치료를 위해 내원한 여성 환자들의 의무 기록 및 방사선사진을 검토하였으며 환자의 연령이 18세 미만이거나 전신 질환, 골격적 기형 또는 측두하악관절 부위의 외상 병력이 있는 경우는 제외되었다. 총 96명의 여성 환자로부터 얻은 RDC/TMD Axis I 을 포함한 임상 검사 결과와 측방 두부규격방사선사진 (lateral cephalogram), 파노라마 방사선사진(panoramic radiograph) 및 횡두개 방사선사진(transcranial radiograph)을 이용한 방사선적 검사 결과를 분석하였다. RDC/TMD를 이용하여 집단을 분류한 후 측방 두부규격방사선사진의 각도 및 길이 요소들을 계측하여 안면의 골격 관계, 상하악 관계 및 치열 관계를 분석하였다. 통계적 분석법으로는 독립표본 t-검정(independent t-test), 일원분산분석(one-way Analysis of Variance; one-way ANOVA) 및 카이제곱 검정(chi-square test)을 이용하였고 다음과 같은 결과를 얻었다. 1. 근육 문제를 진단하는 RDC/TMD Axis I 의 제 1 군 측두 두부방사선적 특징에서 통계적 유의성이 인정되지 않았다. 2. 관절원판 변위를 임상적으로 진단하는 제 2 군에서는 개구 장애를 동반하지 않는 비정복성 관절원판 변위가 있는 경우 관절원판 변위가 없는 정상 집단에 비하여 articular angle이 큰 것으로 나타났다. 3. 관절통, 관절염 및 관절증을 진단하는 제 3 군에서는 articular angle, FMA, Bjork sum, posterior facial height 및 facial height ratio에서 유의한 차이가 있는 것으로 분석되었다. 4. TMD 진단군과 골격적 양상 사이의 관계를 단순화하기 위하여 RDC/TMD Axis I 각 군을 양분법적으로 분류한 뒤 동일 한 방식으로 분석을 시행하였다. 그 결과 제 1 군에서는 overjet, 제 2 군에서는 articular angle, facial height ratio 및 IMPA, 마지막으로 제 3 군에서는 articular angle, gonial angle, facial convexity, FMA, Bjork sum, posterior facial height, facial height ratio 및 ANB angle에서 유의한 차이를 보였다. 이상의 RDC/TMD Axis I 을 이용하여 진단된 측두하악장애 환자를 대상으로 안면의 골격적 양상과 TMD 사이의 연관성 을 분석한 결과로부터 RDC/TMD Axis I 임상 진단에 따라 진단한 측두하악장애 환자 중 제 2 군과 제 3 군의 환자들에서 측두하악장애와 관련된 것으로 알려진 하악골의 후하방 회전으로 인한 골격적 차이가 존재함을 확인하였다. RDC/TMD Axis I은 교정 전 혹은 교정 치료 진행 중에 임상 검사 및 일반 방사선사진으로부터의 제한된 정보를 바탕으로 교정 치료 중 고려하여야 할 TMD 환자를 감별하는데 유용한 정보를 제공할 수 있을 것이다.

• Wind and Structures
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• 제34권1호
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• pp.115-125
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• 2022

The high-Reynolds number flow around a rectangular cylinder, having streamwise to crossflow length ratio equal to 5 is analyzed in the present paper. The flow is characterized by shear-layer separation from the upstream edges. Vortical structures of different size form from the roll-up of these shear layers, move downstream and interact with the classical vortex shedding further downstream in the wake. The corresponding mean flow is characterized by a recirculation region along the lateral surface of the cylinder, ending by mean flow reattachment close to the trailing edge. The mean flow features on the cylinder side have been shown to be highly sensitive to set-up parameters both in numerical simulations and in experiments. The results of 21 Large Eddy Simulations (LES) are analyzed herein to highlight the impact of the lateral mean recirculation characteristics on the near-wake flow features and on some bulk quantities. The considered simulations have been carried out at Reynolds number Re=DU_∞/ν=40 000, being D the crossflow dimension, U_∞ the freestream velocity and ν the kinematic viscosity of air; the flow is set to have zero angle of attack. Some simulations are carried out with sharp edges (Mariotti et al. 2017), others with different values of the rounding of the upstream edges (Rocchio et al. 2020) and an additional LES is carried out to match the value of the roundness of the upstream edges in the experiments in Pasqualetto et al. (2022). The dimensions of the mean recirculation zone vary considerably in these simulations, allowing us to single out meaningful trends. The streamwise length of the lateral mean recirculation and the streamwise distance from the upstream edge of its center are the parameters controlling the considered quantities. The wake width increases linearly with these parameters, while the vortex-shedding non-dimensional frequency shows a linear decrease. The drag coefficient also linearly decreases with increasing the recirculation length and this is due to a reduction of the suctions on the base. However, the overall variation of C_D is small. Finally, a significant, and once again linear, increase of the fluctuations of the lift coefficient is found for increasing the mean recirculation streamwise length.