• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.1
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• pp.172-184
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• 1999

The present study was performed to identify morphologic sub-groupings in Korean children with Class I malocclusions, and to find out anatomic differences between the sub-groups. Standardized lateral cephalometric radiographs of 152 Korean children, aged between 6 and 12 years, with Class I malocclusions were analyzed by the Counterpart Analysis. A statistical method, Ward's Minimum Variance Cluster Analysis, was employed to divide the sample into sub-groups those with similar morphologic characteristics. The results were as follows; 1. There appeared two facial types, Type I and Type II, in Korean children with Class I malocclusions, 48.7% and 51.3%, respectively. 2. In both sub-groups, there existed strong Class III skeletal patterns due to a counterclockwise rotation of the Middle Cranial Fossa alignment, and strong Class II skeletal patterns due to the long Posterior Maxillary vertical dimension and a clockwise rotation of the Ramus alignment. 3. There were no significant differences in Upper Anterior Facial Height between Type I and Type II, $52.6{\pm}2.92mm\;and\;52.8{\pm}3.23mm$, respectively. 4. The Lower Anterior Facial Height in Type II was longer ($66.0{\pm}4.03mm$) due to the long Posterior Maxillary vertical dimension, the clockwise rotation of the Ramus alignment, and a clockwise rotation of the Mandibular plane alignment than that of Type I ($64.2{\pm}4.15mm$).

• The Journal of Korean Academy of Prosthodontics
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• v.14 no.1
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• pp.41-46
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• 1976

The purpose of the current study was to investigate histologic changes in the alveolar bone of the lower molar region subsequent to the loss of their opposite molars, and to characterize chemical alterations by utilization of histochemical procedures. Twenty five rats(Sprague Dawley), approximately 150-200gm body weight, were used in this experiment. In the treated animals, upper molars were removed. The animals were decapitated by groups at the following intervals after teeth removals: 10th, 20th, 50th, 70th and 100th day. The normal, untreated rats were used as controls. The molar region of lower jaw, including the intact alvelar bone and teeth was dissected and specimens were decalcified in 3% formic acid. After the tissues were fully decalcified, the specimens were embedded in celloidin and sectioned in mesiodistal plane. These sections were stained in the following staining methods. Mallory azan stain and hematoxylin-eosin stain were utilized for structural evaluation. Polysaccharides were demonstrated by means of the PAS reaction. Acidmucopolysaccharides were studied by means of the colloidal iron stain. Alloxan-Schiff reaction was used for protein. The results were as follows: 1) In the control animals, bone resorption was noted in the distal alveolar bone proper and bone apposition was shown in the mesial alveolar bone proper. But in the treated animals, bone apposition was observed on the mesial and distal walls of the alveolus and osteoclastic activity was not noted in any walls. 2) Bone apposition was most prominent from the 10th to 20th day after treatment. 3) Appositional growth of cementum along the surface of root was prominent from the 50th to 70th day after treatment. 4) In the area where osteoblastic activity was apparent, osteoblasts were stained strongly in the PAS and alloxan-Schiff reaction. A plastic resorption line showed strong alloxan-Schiff reaction. 5) In the colloidal iron stain, the alveolar wall adjacent to the cementum apposition area was stained more strongly than the other areas.

• The korean journal of orthodontics
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• v.10 no.1
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• pp.15-27
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• 1980

This study was undertaken to compare the craniofacial morphology of Class II, Division 1 malocclusion with that of normal occlusion in children, and to investigate the incidence of various Class II, Division 1 craniofacial skeletal patterns. The subjects consist of thirty seven boys and fifty three girls with Class II, Division 1 malocclusion, and forty six boys and eighty one girls 10-15 years with normal occlusion. Measurements were recorded, tabulated and analyzed on the lateral cephalograms by the degree of SNA, SNB and ANB. The following characteristics of the Class II, Division 1 skeletal pattern were observed. 1. The anteroposterior relationship of the maxilla to the cranium in the Class II, Division 1 was very similar to that of normal occlusion. 2, Mandible of the Class II, Division 1 malocclusion was in the posterior position in relation to the cranial anatomy when compared to normal. 3. The chin point as measured by SN Pog and NS Gn showed distal positioning in relation to normal occlusion. 4. SN to mandibular plane angle was large in Class II, Division 1 malocclusion. 5. Mandibular incisor inclination was not significantly different between Class II, Division 1 malocclusion and normal occlusion, but maxillary incisors inclined and positioned labially and consequently overjet was large in Class II, Division 1 malocclusion. 6. Class II, Division 1 malocclusion was divided into four types of craniofacial skeletal pattern. The most common Class II, Division 1 pattern was found to be type C in which SN-Mand. Pl. was above mean range of normal occlusion. The next frequent pattern was found to be type A in which maxilla and mandible were within normal range of protrusion while upper incisors were severly labially inclined.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.8
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• pp.781-787
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• 2004

In this paper, a novel dual and wide band aperture stacked patch antenna for Cellular/PCS/IMT-2000 base station is presented. It consists of single microstrip patch having notches along the radiating patch, two dielectric substrates and a form material. To achieve wide band characteristic, we utilize the coupling effect between the notched patch and the resonant aperture in the ground plane and by properly cutting notches on the patch, an aperture stacked patch antenna could be designed to yield dual frequency operation. By the proper choice of resonant aperture size and height of a foam material, dual and wide band characteristic could be realized the measured impedance bandwidth(1:1.5 VSWR) of designed antenna at lower band(860 MHz) reaches 77 MHz and covers the Cellular CDMA band(824∼894 MHz). The measured impedance bandwidth(1:1.5 VSMR) of the designed antenna at upper band(1,960 MHz) is about 550 MHz and covers both the PCS band(1,750∼l,870 MHz) and the for-2000 band(1,920∼2,170 MHz). Good broadside radiation with high gain(5.65∼7.4 dBi) characteristics have also been observed.

• The Journal of Korean Physical Therapy
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• v.32 no.5
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• pp.319-324
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• 2020

Purpose: This study was to investigate the effect of dorsal neck muscle fatigue on the cervical range of motion (CROM) and proprioception in adults with the forward head posture (FHP). Methods: Thirty pain-free subjects were enrolled in this study. All subjects were measured the forward head angle by taking the capture of the sagittal plane of their upper body to determine the FHP. Subjects were distributed into two groups: the FHP group (n=14) and Control group (n=16). All subjects were measured the CROM and the Head repositioning accuracy (HRA) for joint proprioception before and after inducing muscle fatigue of the dorsal neck. The CROM and HRA were measured in neck flexion, extension, right-left lateral flexion, and right-left rotation. Sorenson's test was used to induce muscle fatigue of the dorsal neck. Results: Total CROMs were significantly decreased after dorsal neck muscle fatigue in both groups (p<0.05). Total HRAs were significantly increased after dorsal neck muscle fatigue in the FHP group (p<0.05), but there were no significant differences in the control group (p>0.05). Total CROM changes were not significant differences between groups (p>0.05), but total HRA changes were significant differences between groups (p<0.05) except for right and left lateral flexion (p>0.05). Conclusion: Immediate CROM and proprioception reduction after the dorsal neck muscle fatigue were observed in adults with the FHP. Therefore, FHP can significantly affect the CROM and positioning consistency of cervical proprioception.

• Bulletin of the Korean Mathematical Society
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• v.55 no.3
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• pp.957-965
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• 2018

We study the class $C{\mathcal{V}} ({\Omega})$ of analytic functions f in the unit disk ${\mathbb{D}}=\{z{\in}{\mathbb{C}}$ : ${\mid}z{\mid}$ < 1} of the form $f(z)=z+{\sum}_{n=2}^{\infty}a_nz^n$ satisfying $$1+\frac{zf^{{\prime}{\prime}}(z)}{f^{\prime}(z)}{\in}{\Omega},\;z{\in}{\mathbb{D}}$$, where ${\Omega}$ is a convex and proper subdomain of $\mathbb{C}$ with $1{\in}{\Omega}$. Let ${\phi}_{\Omega}$ be the unique conformal mapping of $\mathbb{D}$ onto ${\Omega}$ with ${\phi}_{\Omega}(0)=1$ and ${\phi}^{\prime}_{\Omega}(0)$ > 0 and $$k_{\Omega}(z)={\displaystyle\smashmargin{2}{\int\nolimits_{0}}^z}{\exp}\({\displaystyle\smashmargin{2}{\int\nolimits_{0}}^t}{\zeta}^{-1}({\phi}_{\Omega}({\zeta})-1)d{\zeta}\)dt$$. Let $z_0,z_1{\in}{\mathbb{D}}$ with $z_0{\neq}z_1$. As the first result in this paper we show that the region of variability $\{{\log}\;f^{\prime}(z_1)-{\log}\;f^{\prime}(z_0)\;:\;f{\in}C{\mathcal{V}}({\Omega})\}$ coincides wth the set $\{{\log}\;k^{\prime}_{\Omega}(z_1z)-{\log}\;k^{\prime}_{\Omega}(z_0z)\;:\;{\mid}z{\mid}{\leq}1\}$. The second result deals with the case when ${\Omega}$ is the right half plane ${\mathbb{H}}=\{{\omega}{\in}{\mathbb{C}}$ : Re ${\omega}$ > 0}. In this case $CV({\Omega})$ is identical with the usual normalized class of convex univalent functions on $\mathbb{D}$. And we derive the sharp upper bound for ${\mid}{\log}\;f^{\prime}(z_1)-{\log}\;f^{\prime}(z_0){\mid}$, $f{\in}C{\mathcal{V}}(\mathbb{H})$. The third result concerns how far two functions in $C{\mathcal{V}}({\Omega})$ are from each other. Furthermore we determine all extremal functions explicitly.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.5
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• pp.89-100
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• 2001

The Ritz method Is applied In a three-dimensional (3-D) analysis to obtain accurate frequencies for thick. linearly tapered. annular plates. The method is formulated for annular plates haying any combination of free or fixed boundaries at both Inner and outer edges. Admissible functions for the three displacement components are chosen as trigonometric functions in the circumferential co-ordinate. and a1gebraic polynomials in the radial and thickness co-ordinates. Upper bound convergence of the non-dimensional frequencies to the exact values within at least four significant figures is demonstrated. Comparisons of results for annular plates with linearly varying thickness are made with ones obtained by others using 2-D classical thin place theory. Extensive and accurate ( four significant figures ) frequencies are presented 7or completely free. thick, linearly tapered annular plates haying ratios of average place thickness to difference between outer radius (a) and inner radius (b) radios (h$_{m}$/L) of 0.1 and 0.2 for b/L=0.2 and 0.5. All 3-D modes are included in the analyses : e.g., flexural, thickness-shear. In-plane stretching, and torsional. Because frequency data liven is exact 7o a\ulcorner least four digits. It is benchmark data against which the results from other methods (e.g.. 2-D 7hick plate theory, finite element methods. finite difference methods) and may be compared. Throughout this work, Poisson\`s ratio $\upsilon$ is fixed at 0.3 for numerical calculations.s.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.10
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• pp.868-874
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• 2007

Noises from the helicopter rotor model are calculated numerically at various pitch angles. The aerodynamic data are calculated by using prescribed wake model and unsteady panel method. The distribution of aerodynamic loads on the blade surface are obtained from $0^{\circ}$ to $9^{\circ}$ pitch angles with equiangular increments of $1.5^{\circ}$. Although thickness noise is not related to the change of pitch angles, loading noise level increases about 3~4dBA every $1.5^{\circ}$ increment of pitch angle. The additive noise level shows sufficient value to perceive the loudness. From the result of directivity pattern the sound level at the lower region of the blade disc plane is higher than that of the upper region.

• Archives of Plastic Surgery
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• v.32 no.2
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• pp.262-266
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• 2005

In some blepharochalasis patients, upper blepharoplasty alone is not satisfactory because of narrow distance between eyebrow and eyelash. On that occasion, eyebrow lift is advisable. There are many methods of classical eyebrow lift, such as direct excision, transblepharoplasty approach, anterior hairline technique, and so on. But they are not so effective, have a tendency to recur and also give rise to side effects; unacceptable scar, facial nerve palsy, sensory loss and hematoma, etc. Some patients who have prominent nasolabial folds, are reluctant to perform face lift procedure due to psychologic or economic burden. The authors performed the eyebrow lift procedure separately or simultaneously with face lift or forehead lift. After making 2 or 3 slit incisions, we passed absorbable suture material, 3-0 vicryl, through suborbicularis oculi fat layer. Then it was passed through subperiosteal plane and fixated to the temporalis fascia. When patients complain prominent nasolabial folds, malar fat pad was elevated also in the same manner. This methods is effective and has minimal complication such as facial nerve palsy, scar, sensory loss. Recurrent tendency was rarely observed during follow-up. Dimples were observed at slit incision sites but they disappeared within 2 or 3 weeks. Eyebrow lift and malar fat lift by absorbable suture elevation with subperiosteal dissection is a simple and less morbid. Because of its effectiveness and little side effect or complication, this procedure can be a useful method.

• Atmosphere
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• v.23 no.1
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• pp.1-11
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• 2013

The angular momentum transport of an idealized axisymmetric vortex in the developing stage was investigated using the Weather Research and Forecast (WRF) model. The balanced axisymmetric vortex was constructed based on an empirical function for tangential wind, and the temperature, geopotential, and surface pressure were obtained from the balanced equation. The numerical simulation was carried out for 6 days on the f-plane with the Sea Surface Temperature (SST) set as constant. The weak vortex at initial time was intensified with time, and reached the strength of tropical cyclone in a couple of days. The Absolute Angular Momentum (AAM) was transported along with the secondary circulation of the vortex. Total AAM integrated over a cylinder of radius of 2000 km decreased with simulation time, but total kinetic energy increased rapidly. From the budget analysis, it was found that the surface friction is mainly responsible for the decrease of total AAM. Also, contribution of the surface friction to the AAM loss was about 90% while that of horizontal advection was as small as 8%. The trajectory of neutral numerical tracers following the secondary circulation was presented for the Lagrangian viewpoint of the transports of absolute angular momentum. From the analysis using the trajectory of tracers it was found that the air parcel was under the influence of the surface friction continuously until it leaves the boundary layer near the core. Then the air parcel with reduced amount of angular momentum compared to its original amount was transported from boundary layer to upper level of the vortex and contributed to form the anti-cyclone. These results suggest that the tropical cyclone loses angular momentum as it develops, which is due to the dissipation of angular momentum by the surface friction.