• Journal of Korean Society of Steel Construction
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• v.16 no.6 s.73
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• pp.759-768
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• 2004

The parametric analysis of vertically braced steel pipe arch ribs was performed to evaluate their in-plane buckling strengths and ultimate load-carrying capacities. The elastic and plastic behavior of braced arch ribs, unlike those of the usual single arch ribs, are affected by such factors as the flexural rigidity of the brace member, brace and pipe ribs spacing, loading situation, and arch curvature. To analyze these effects, several parameters were included, such as the rise-to-span ratio, the second moment of the inertia ratio of the rib to the brace member, the space ratio of the brace, the space ratio of the upper and lower ribs, the initial crookedness, the slenderness ratios of the braced arch ribs, and the loading conditions were considered with live-load-to-dead-load ratios. Based on the results of the parametric analyses, a proper profile of the braced arch rib was proposed. A large-scale structural experiment was also performed to evaluate the ultimate strength of the braced arch rib. The test results were determined to reasonably coincide with the analytical ones.

• The korean journal of orthodontics
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• v.34 no.3 s.104
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• pp.219-227
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• 2004

The purpose of this study was to evaluate the spatial changes of mesial-in rotated maxillary molar and opposite anchor tooth during derotation by the precision transpalatal arch (TPA) with the use of a new typodont simulation system, the Calorific machine system, which was designed to observe the whole process of tooth movement. The maxillary right first molar was used for the anchor tooth and the maxillary left first molar was used for the mesial-in rotated tooth, and the angle of rotation was increased to 20,40, and 60. A passive precision TPA was fabricated and then activated by bending the left arm to 20, 40, and 60. Each experiment was repeated five times under the same conditions and analyzed by ANOVA and Tucky's Studentized Range (HSD) test. In the occlusal plane, when the bending angle of precision TPA was increased, the mesiobuccal cusp of the rotated molar moved more buccally (p<0.001) and less distally (p<0.001) while the distolingual cusp moved in the mesiopalatal direction. In the sagittal plane, the palatal roots of the derotated molar moved mesially (p<0.001). In the traverse plane, the derotated molar showed slight extrusion (p<0.001). The upper right first molar, which was used as an anchor tooth, showed clinically insignificant movement across all three planes.

• The korean journal of orthodontics
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• v.27 no.2
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• pp.197-208
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• 1997

Class III malocclusion patients can be approached with many different types of treatment methods, and thus, each patient's problems must be accurately evaluated to allow selection of the best possible treatment method. Cephalometric analysis is an essential part of diagnosis and treatment planning of orthodontic patients, and it would certainly be helpful if reliable cephalometric guidelines could be set. The author divided 482 Class III malocclusion patients(253 males and 229 females) into fourgroups according to different types of treatment methods they have received to correct imbalance between upper and lower jaws: 1) orthopedic appliance (face mask & RPE), 2) camouflage treatment with fixed appliance, 3) surgical-orthodontic treatment, 4) cross-bite correction with removable plates/ functional appliance. Cephalometric values at the time of first clinical examination were compare among the four groups. Cephalometric analysis indicates the following results: 1)the amounts of antero-posterior and vertical skeletal discrepancies and dental compensation were greatest in surgery group 2) SNB, Wits, distance from Nasion Perpendicular Plane to point a facial angle, facial convexity, and APDI were greater in orthopedic appliance group than fixed appliance(camouflage) group, but there was no statistical difference 3) removable plates/ functional appliance group showed least amounts of skeletal discrepancies and dental compensation with statistical significance.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.5
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• pp.447-453
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• 2010

The hemifacial microsomia is characterized by variable underdevelopment of the craniofacial skeleton, external ear, and facial soft tissues. So, patients with hemifacial microsomia have an occlusal plane canting and malocclusion with facial asymmetry. Distraction osteogenesis (DO) with an intraoral or extraoral device is a technique using tension to generate new bone with gradual bone movement and remodeling. DO has especially been used to correct craniofacial deformities such as a hemifacial microsomia, facial asymmetry, and mandible defect that could not adequately be treated by conventional reconstruction with osteotomies. It has a significant advantage to lengthen soft and hard tissue of underdeveloped site without bone graft and a few complication such as nerve injury or muscle contracture. A 13-years old girl visited our clinic for the chief complaint of facial asymmetry. She had a left hypoplastic maxilla and mandible, occlusal plane canting and malocclusion. We diagnosed hemifacial microsomia and lanned DO to lengthen the affected side. Le Fort I osteotomy, left mandibular ramus and symphysis osteotomy were performed. The internal distraction devices fixed with screw on maxillary and mandibular ramus osteotomy sites. External devices were adapted to lower jaw for DO on symphysis osteotomy site and to upper jaw for rapid maxillary expansion (RME). At 7days after surgery, distraction was started at the rate of 1mm per day for 13days, and after 4months consolidation periods, distraction devices were removed. Simultaneous multiple maxillo-mandibular distraction osteogenesis with RME resulted in a satisfactory success in correcting facial asymmetry as well as occlusal plane canting for our hemifacial microsomia.

• The korean journal of orthodontics
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• v.27 no.6 s.65
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• pp.881-889
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• 1997

The purpose of this study was to compare four groups of Oriental young adults (169 males and 174 females) with normal occlusion and well balanced faced. Lateral cephalograms of 100 Koreans, 100 Chinese, 72 Vietnamese and 71 Japanese were digitized and six profile measures were computed. Analyses of variance showed that total facial profile(Gl'-Pr'-Pg') of Chinese was significantly less convex than the profile of Koreans or Vietnamese. Facial profile(Gl'-Pr'-Pg') of Chinese was also significantly less convex than that of Vietnamese. Holdaway's soft tissue angle(Pg'-LS:N-B) was significantly greater in Vietnamese than Chinese and Koreans, who were in turn greater than Japanese. The upper lip of Vietnamese is significantly closer to Ricketts' esthetic plane, than Chinese; Koreans and Japanese are significantly further behind the plane than Chinese. The lower lip of Koreans and Japanese was close to the esthetic plane, while Chinese and Vietnamese were approximately 2mm ahead. The nasolabial angle was significantly smaller for Chinese and Japanese than Koreans and Vietnamese. Sex differences were primarily dependent on the nose; total facial convexity and the nasolabial angle wert significantly larger in females than males. The results of this study demonstrate that a single standard of facial Profile is not sufficient or appropriate for Oriental patients.

• The korean journal of orthodontics
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• v.16 no.1
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• pp.85-106
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• 1986

The purpose of this investigation was to know the means of the T.M.J. space and to compare spational differences in centric relation and centric occlusion by the T.M.J. Tomogram and to study the correlation between the articular eminence slope and the lingual surface slope of the maxillary central incisor by the Cephalogram in near normal occlusion subjects. These results could give contribution for the diagnosis of orthodontic treatment and T.M.J. dysfunction and the assessment of orthopedic treatment and orthognathic surgery. 44 young adults (28 men and 16 women, 21 to 27 years of age) were selected from the Dental students in Yonsei Univ. Criteria for selection was normal occlusion, no clinical signs and T.M.J. dysfunction, no history of orthodontic treatment, and no missing tooth. After submental vertex view analysis. each subject was given the T.M.J. Tomogram in centric relation and centric occlusion and the Cephalogram was given with Quint Sectograph. All data was recorded and statistically processed with the CYBER computer system. Results were analyzed: the following findings and conclusions were derived. 1. The mean value for the combined right and left anterior joint space was 2.549mm, the posterior space was 2.260mm, and superior space was 3.31mm in centric relation. The anterior space was 2.316mm, posterior space was 2.474mm, and superior space was 3.435mm in centric occlusion. 2. In the centric relation position, both condyles were placed more posterioly and superioly in their fossae than in the centric occlusion position by the spatial difference. 3. In the centric occlusion position, both condyles were more symmetrically placed in their fossae with equal anterior-posterioly rather than in the centric relation position. 4. The mean articular eminence angle was $48.19^{\circ}$ and the mean fossa height was 7.911mm. A strong positive correlation between the articular eminence angle and fossa height in T.M.J. Tomogram was found. 5. In Cephalometric analysis, there was a strong positive correlation between the articular eminence slope and the lingual surface slope of the upper central incisor to the FH plane, occlusal plane, and S-N plane. 6. There was moderate positive correlation between the S-E measurements and the fossa height, articular eminence angle, and DcGn < F-H.

• The korean journal of orthodontics
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• v.18 no.2
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• pp.343-366
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• 1988

Craniofacial complex is influenced by numerical skeletal elements. Though the analysis of growth change has been done by various analytical methods, it was dependent on any method of registration and superimposition, based on reference plane and reference point. However, the craniofacial growth is composed of a number of local growth elements. Therefore, it will be necessary to use a clinically useful method for estimating craniofacial skeletal growth independently. The author analysed longitudinal cephalometric roentgenogram of 15 Korean males and 15 Korean females aged from 6 to 12 years by the finite element method and results were as follows : 1. The finite element method for craniofacial skeletal complex and soft tissue made it possible to analyze the independent local growth. 2. Regression equations from the value of each strain will make it possible to predict the craniofacial growth. 3. The growth of anterior cranial base was different from that of other facial bone. 4. The growth of posterior cranial base influenced the growth of upper pharyngeal region, midfacial region, maxilla and posterior region of mandible. 5. The growth of maxillary complex was vertical rather than horizontal. 6. The growth direction of ramus, mandibular body, alveolar bone was various. 7. The relation between hard tissue and soft tissue by finite element method was variant.

• Physical Therapy Korea
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• v.25 no.2
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• pp.71-77
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• 2018

Background: There are insufficient objective or quantitative evidence for the better intervention to improve proprioception particularly for the application of external load. There are conflicting opinions whether the external load is effective for proprioception improvement or not. Objects: The purpose of this study was to investigate effects of external load on proprioception of shoulder joint quantitatively using 3D motion capture system. Methods: Nine healthy adults joined for this study. They were asked to perform scapular plane abduction motion with attaching reflective markers on the trunk and upper limb. The 3D positions of finger marker, while they performed the same task with and without external load, were recorded and analyzed. Results: All participants showed decreased variable errors in the vertical direction when the external load was applied (p<.02). Even though other directions (y, z) and absolute errors increased, they did not have statistical significances. Conclusion: Based on this study results, the external load application would be effective for shoulder joint position sense improvement.

• Radiation Oncology Journal
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• v.1 no.1
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• pp.37-40
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• 1983

Whole brain irradiation is one mode in the treatment of brain cancer and brain metastasis, but it might cause brain injury such as brain necrosis. It has been studied whether the dose distribution could be a cause of brain injury. The dose distribution in whole brain irradiated by Co-60 beam has been measured by means of calibrated TLD chips inserted in the brain of Humanoid phantom. The following results were obtained. 1. Dose distribution on each transverse section of the brain was uniform. 2. On the midsagital plane of the brain, the dose was highest in upper portion and lowest in lower portion, varying 8 from 104% to 90%. 3. When the radiation field includes free space of 2cm or more width out of the head, the dose distribution in the whole brain is almost independent of the field width. 4. It is important to determine adequate shielding area and to set shielding block exactly in repetition of treatment.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.542-547
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• 2001

A non-intrusive Planar Laser-Induced Fluorescence(PLIF) technique was applied to study the turbulent mixing process in a Rushton turbine reactor. Instantaneous and ensemble averaged concentration fields are obtained by measuring the fluorescence intensity of Rhodamine B tracer excited by a thin Nd:Yag laser sheet illuminating the whole center plane of the stirred tank. The gray level images captured by a 14-bit cooled CCD camera can be transformed to the local concentration values using a calibration matrix. The dye injection point was selected at the tank wall with three quarter height (3/4H) from the tank bottom to observe the mixing characteristics in upper bulk flow region. There exist distinct two time scales: the rapid decay of mean concentration in each region after the dye infusion reflects the large scale mixing while the followed slow decay reveals the small scale mixing. The temporal change of concentration probability functions conjectures the two sequential processes in the batch type mixing. An inactive column of water existed above the impeller disk, in which the fluid rotates with the shaft but is isolated from the mean bulk flow.