• The korean journal of orthodontics
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• v.34 no.4 s.105
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• pp.313-324
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• 2004

The Purpose of this study was to investigate the predictors of relapse in orthodontic treatment of skeletal Class III malocclusion in growing patients. A total of 55 patients were studied and all subjects were divided into two groups according to their stability in the post-treatment stage. Of the sample, 33 patients were included in the stable group and the remaining 22 were assigned to the relapse group. Cephalometric data of the pre-treatment stage was taken and compared between the stable and relapse group. The following results were obtained through t-test: 1. This study presented statistical evidence to show that the major skeletal determinant of prognosis in Class III orthodontic treatment was not anteroposterior discrepancy .but vertical discrepancy, especially within the AB-maxillo mandibular triangle. Vertical angular measurements that showed statistically significant differences were AB-MP and ODI(P<0.01) and the vortical ratio measurements were MP-P/AL and PP-P/AL(P<0.05). 2. Relapse tendency increased with the steep occlusal Plane, especially the steep lower occlusal plane. As to occlusal plane, there were statistically significant differences in OP(L)-PP, OP-PP, AB-OP(L) and Wits appraisal(P<0.05). This study claimed that anteroposterior discrepancy was not necessarily the proper criteria to predict relapse. Vertical discrepancy had a significant effect on post-treatment stability.

• Journal of the Korea Society of Computer and Information
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• v.27 no.3
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• pp.63-69
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• 2022

In this paper, we propose a new GPU-based framework for quickly calculating adaptive and continuous SDF(Signed distance fields), and examine cases related to rendering/collision processing using them. The quadtree constructed from the triangle mesh is transferred to the GPU memory, and the Euclidean distance to the triangle is processed in parallel for each thread by using it to find the shortest continuous distance without discontinuity in the adaptive grid space. In this process, it is shown through experiments that the cut-off view of the adaptive distance field, the distance value inquiry at a specific location, real-time raytracing, and collision handling can be performed quickly and efficiently. Using the proposed method, the adaptive sign distance field can be calculated quickly in about 1 second even on a high polygon mesh, so it is a method that can be fully utilized not only for rigid bodies but also for deformable bodies. It shows the stability of the algorithm through various experimental results whether it can accurately sample and represent distance values in various models.

• Journal of Mechanical Science and Technology
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• v.20 no.11
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• pp.1881-1890
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• 2006

In this paper, a Petrov-Galerkin natural element method (PG-NEM) based upon the natural neighbor concept is presented for the free vibration and dynamic response analyses of two-dimensional linear elastic structures. A problem domain is discretized with a finite number of nodes and the trial basis functions are defined with the help of the Voronoi diagram. Meanwhile, the test basis functions are supported by Delaunay triangles for the accurate and easy numerical integration with the conventional Gauss quadrature rule. The numerical accuracy and stability of the proposed method are verified through illustrative numerical tests.

• Analyses & Alternatives
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• v.7 no.3
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• pp.1-26
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• 2023

This article will analyze and forecast important variables and dynamics in global power politics after the war in Ukraine. It tries to use several perspectives to analyze international relations, particularly liberal internationalism and structural realism. In short, core variables are as follows; First, how is the US-led liberal international order and globalization being adjusted? Second, how will the U.S.-China strategic competition, which is the biggest and structural variable, cause changes in the international order in the future? The third variable, how stable are Sino-Russia relations in the context of a structuring U.S.-China-Russia strategic new triangle? Fourth, to what extent will third middle hedging states outside the U.S. and China be able to exercise strategic autonomy in the face of multipolarization? To summarize, the first of these four variables is the largest basic variable at the global political and economic level in terms of its impact on the international community, and it has been led by the United States. The second variable, in terms of actors, seems to be the most influential structural variable in global competition, and the US-China strategic competition is likely to be a long game. Thus the world will not be able to escape the influence of the competition between the two global powers. For South Korea, this second variable is probably the biggest external variable and dilemma. The third variable, the stability of Sino-Russia relations, determines balance of global power in the 21st century. The U.S.-China-Russia strategic new triangle, as seen in the current war in Ukraine, will operate as the greatest power variable in not only global power competition but also changes in the international order. Just as the U.S. is eager for a Sino-Russia fragmentation strategy, such as a Tito-style wedge policy to manage balance of power in the early years of the Cold War, it needs a reverse Kissinger strategy to reset the U.S.-Russia relationship, in order to push for a Sino-Russia splitting in the 21st century. But with the war in Ukraine, it seems that this fragmentation strategy has already been broken. In the context of Northeast Asia, whether or not the stability of Sino-Russia relations depends not only on the United States, but also on the Korean Peninsula. Finally, the fourth variable is a dependent variable that emerged as a result of the interaction of the above three variables, but simultaneously it remains to be seen that this variable is likely to act as the most dynamic and independent variable that can promote multilateralism, multipolarization, and pan-regionalism of the global international community in the future. Taking into account these four variables together, we can make an outlook on the change in the international order.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.753-760
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• 2003

An existing studies concern about movement of pile bridge abutments. However, lateral displacement cause the serious failure of bridge by embankment under soft soil lateral flow A intention is obtained by analyzing the relationship between the safety factor of evaluation for lateral movements. Precise investigation and analysis are performed, in which the lateral movement of bridge abutments has occurred, and construct design strut-slab between bridge abutments in order to restraint lateral flow. As a result of this study, it was found that when evaluation for lateral movements is allowed to use Tschebotarioff's method and lateral flow decision number (I) and revision lateral flow decision number (M$_{I}$) by Korea Highway Corporation. Most important thing is decision of pressure of lateral flow at this case. Tschebotarioff's isoscales triangle method have no trouble analysis of pressure of lateral flow. Strut-slab method are nearly not have constructed case in this field site study that applied method. The method are between abutments combined steel strut and reinforced concrete slab. This method are effective restraint lateral flow but have little difficulty if long span bridge between abutments.s.

• Geomechanics and Engineering
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• v.2 no.2
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• pp.89-106
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• 2010

Sliding within the dam foundation is one of the key failure modes of a gravity dam. A two-dimensional (2-D) physical model test has been conducted to study the sliding failure of a concrete gravity dam under overloading conditions. This model dam was instrumented with strain rosettes, linear variable displacement transformers (LVDTs), and embedded fiber Bragg grating (FBG) sensing bars. The surface and internal displacements of the dam structure and the strain distributions on the dam body were measured with high accuracy. The setup of the model with instrumentation is described and the monitoring data are presented and analyzed in this paper. The deformation process and failure mechanism of dam sliding within the rock foundation are investigated based on the test results. It is found that the horizontal displacements at the toe and heel indicate the dam stability condition. During overloading, the cracking zone in the foundation can be simplified as a triangle with gradually increased height and vertex angle.

• Wind and Structures
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• v.22 no.6
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• pp.663-684
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• 2016

Conical vortices generated at the corner regions of large-span flat roofs have been investigated by using the Particle Image Velocimetry (PIV) technique. Mean and instantaneous vector fields for velocity, vorticity, and streamlines were measured at three visual planes and for two different flow angles of $15^{\circ}$. The results indicated that conical vortices occur when the wind is not perpendicular to the front edge. The location of the leading edge corresponding to the negative peak vorticity and maximum turbulent kinetic energy was found at the center of the conical vortex. The wind pressure reaches the maximum near the leading edge roof corner, and a triangle of severe suctions zone appears downstream. The mean pressure in uniform flow is greater than that under turbulent flow condition, while a significant increase in the fluctuating wind pressure occurs in turbulent streams. From its emergence to stability, the shape of the vortex cross-section is nearly elliptical, with increasing area. The angle that forms between the vortex axis and the leading edge is much smaller in turbulent streams. The detailed flow structures and characteristics obtained through FLUENT simulation are in agreement with the experimental results. The three dimensional (3-D) structure of the conical vortices is clearly observed from the comprehensive arrangement of several visual planes, and the inner link was established between the vortex evolution process, vortex core position and pressure distribution.

• Economic and Environmental Geology
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• v.7 no.4
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• pp.175-184
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• 1974

Weathering of granites has a great geochemical significance, because of their chemical stability near the earth surface which is more pronounced than in most other rocks. The author intended to observe the relative mobility of major elements in weathering process of the granite, distributed on outskirts of Iri city Jeolla-bugdo, Korea. He analysed fresh granites and weathered ones from the Baeg-Gu granite mass and obtained following conclusions in the triangle-diagrams and the oxidized variation diagrams of the samples. 1) The increasing phenomena of $H_2O$ was observed clearly in early and late stages of weathering process. 2) The early stage of weathering is commenced by physical weathering and followed by chemical weathering. 3) The ratio of $FeO/Fe_2O_3$, FeO/MgO, and $SiO_2/Al_2O_3$ decreased uniformly from early to late stage of weathering processes. 4) It was proved that weathering potential of granite was larger than that of basaltic rock. 5) The order of mobility in major elements was Ca, Na and K

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.4
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• pp.348-357
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• 1988

The present work was undertaken to investigated the purification and characterization of polyphenol oxidase (PPO ; EC 1.10.3.1) in sweet potato, particularly the number of PPO isozymes, and PPO properties such as pH optimum, heat stability, substrate specificity, kinetics, and inhibitor studies. The purification achieved was 23.1 fold from crude extract with a yield of 41.5%. Eight PPO isozymes and twelve PPO isozymes were detected by disc polyacrylamide gel electrophoresis and isoelectric focusing, respectively. The specific activity of each isozyme separated by isoelectric focusing was in the range of $6,000{\sim}46,700U/mg$. This enzyme was sweet below $65^{\circ}C$ and the pH optimum of PPO occurred at 6.0-6.5. The substrate specificity of sweet potato PPO showed the high affinity toward the odiphenolic compounds. Km and Vmax for catechol were found to be 6.7 mM and $20{\triangle}A/min$, me protein, respectively. Inhibitor studies indicated that dithiothreitol was the most potent among the inhibitors used in the present work.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.2
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• pp.60-67
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• 2010

We designed Average Current Control PFC IC which has make the average value of boost inductor current became the shape of sine wave. Designed IC has fixed frequency of 75kHz to meet EMI standard requirement. And also RC compensation loop has been designed into the error amp and the current amp, in order that it has wide bandwidth for high speed control. And we use the oscillator which generates by square wave and triangle wave, and add to UVLO, OVP, OCP, TSD which is in order to operate stability. We simulated by using Spectre of Cadence to verify the unity power factor function and various protection circuits and fabricated in a $1{\mu}m$ High Voltage(20V) CMOS process.