• Title/Summary/Keyword: 비대칭경사

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The relationship between facial asymmetry and maxillary dental arch shape (안면비대칭과 상악치열궁형태의 연관성에 관한 연구)

  • Kim, Dong-U;Son, Won-Sung
    • The korean journal of orthodontics
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    • v.27 no.3 s.62
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    • pp.445-456
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    • 1997
  • This study was designed to examine the dental asymmetry in person with facial asymmetry and to examine the relationship between the degree of mandibular deviation and asymmetry of maxillary dental arch. The sample!, were divided to asymmetry group and normal group. The asymmetry group consisted of 21 subjects(6 males and 15 females) and their mean age was 23.5 years. The normal group consisted of 20 subjects(10 males and 10 females) and their mean age was 18.6 years. Anteroposterior, transverse position of all maxillary teeth except 3rd molars, vortical position of maxillary 1st molars, and angulation of central incisors were measured. The anterioposterior and transverse positions of teeth were measured on the maxillary dental casts, the vertical position of maxillary 1st molars and angulation of maxillary incisors were measured on posteroanterior cephalometric radiographs. The data were analyzed to examine whether significant asymmetries existed in each of the asymmetry and normal groups. The results of this study were as follows : 1. In the asymmetry group, the correlation between the degree of mandibular deviation and that of 3-dimensional dental asymmetry was not so high. 2. In the asymmetry group, the teeth in deviated side were more laterally positioned than that of undeviated side. There were differences in the anteroposterior position of maxillary 1st and 2nd molars and the angulation of maxillary central incisors. 3. In the asymmetry group, the transverse asymmetry was larger in the posterior teeth rather than in the anterior teeth and larger than the anteroposterior asymmetry.

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비대칭 고속 쌍동선의 선미터널 입구영역 경사각 변화에 따른 유체역학적 특성 연구

  • Park, Geun-Hong;Lee, Gyeong-U;Seo, Gwang-Cheol;Kim, Sang-Won
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2018.11a
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    • pp.218-219
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    • 2018
  • 쌍동선형은 단동선형에 비해 안정성 및 저항성능이 우수하며 그 형상은 일반적으로 대칭 및 비대칭으로 구분한다. 이러한 쌍동선은 고속으로 운항하는 경우 선체사이의 파랑 중첩현상을 줄이기 위해 주로 비대칭선형을 사용한다. 또한, 중소형선박은 선미터널을 적용하여 추력효율을 향상시킨다. 본 연구에서는 비대칭 고속 쌍동선의 선미터널 입구영역의 경사각 변화에 따른 유체역학적 특성(저항성능, 항주자세, 압력분포)에 대한 수치해석 연구를 수행하였다. 수치해석은 상용프로그램 STAR CCM+를 이용하였다.

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Horizontal Stress Based on the Calculation of Lateral Stress Ratio in Unsymmetrical Space (비대칭 공간의 수평응력비 산정에 따른 수평응력에 관한 연구)

  • Moon Chang-Yeul;Lee Soo-Ki;Kwon Seung-Joon
    • Journal of the Korean Geotechnical Society
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    • v.20 no.9
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    • pp.177-189
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    • 2004
  • The backfilled space carl have various shapes such as vertical or lateral symmetric, unsymmetric slope depending on field conditions. Kellogg (1993) suggested the different equations for the backfill earth pressure and the lateral stress ratio considering that the stresses are different between the symmetrically sloped backfilled space and the vertical one. Kellogg (1993) assumed the stress generated on sloped wall surface as the simple internal friction angle of backfilled soil. However, Moon (1997) suggested modified Kellogg equation assuming that stress behavior in the sloped wall will be varied according to the rotation angle of principal stress and the friction of sloped wall surface. This study has compared and investigated the horizontal stresss of unsymmetrical backfilled space numerically and experimentally obtained when Kellogg lateral stress ratio is appled to and when average lateral stress ratio considering unsymmetric backfill slop of left and right are applied to the modified Kellogg equation. It is shown that the horizontal stress on the sloped wall has good match numerically and experimentally in the modified Kellogg equation when Kellogg's lateral stress ratio in symmetric condition is applied to the unsymmetric condition. But the horizontal stress on the vertical wall shows disagreement numerically and experimentally. The horizontal stress results in good agreement numerically and experimentally when the average lateral stress ratio of left and right at unsymmetric slop as applied to the modified Kellogg equation. Therefore, it is estimated that the application of the average lateral stress ratio to the left and right wall should be considered when backfilled space formed unsymmetric conditions.

The Effect of Trailing Wake Asymmetry on a Propeller Blade Forces in Inclined Inflow (비대칭 후류를 고려한 경사축 추진기의 유동해석)

  • Sang-Woo Pyo
    • Journal of the Society of Naval Architects of Korea
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    • v.35 no.1
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    • pp.24-31
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    • 1998
  • Unsteady propeller blade forces arising from shaft inclination have been found to be an important contribution tn total blade forces. The position of the wake relative to a blade oscillates with the first blade frequency, thus giving rise to unsteady blade forces which is significant relative to the forces produced directly by flow inclination. In order to find a wake geometry due to shaft inclination, a non-axisymmetric wake model is developed and applied to a specific case, which has experimental values. Predicted cavity shapes and unsteady forces acting on the blades of an inclined shaft propeller are compared to those predicted by other numerical methods, as well as those measured in experiments.

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Analysis of Dynamic Behavior of Group Piles in Asymmetric Ground (비대칭지반에 설치된 무리말뚝의 동적거동 분석)

  • Kyungil Cho;Hongsig Kang;Kusic Jeong;Kwangkuk Ahn
    • Journal of the Korean GEO-environmental Society
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    • v.24 no.10
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    • pp.41-49
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    • 2023
  • Structures such as bridge columns installed on the asymmetric ground such as mountain areas and sloping ground are subject to various loads such as wind, temperature, earthquake, and etc. The pile foundation is generally applied to bridge columns on the asymmetric ground in order to stably support structures. The behavior of the pile foundation supporting bridge columns changes due to various load conditions. In particular, ground-pile-structure interactions should be studied to analyze the behavior of the pile foundation that supports bridge columns effected by dynamic loads such as earthquakes. The pile foundation installed on the asymmetric ground effected by the earthquake has the complicated dynamic interaction between the foundation and the ground due to the ground slope, the difference in soil resistance according to the shaking direction, and the ground movements. In this study, the 1g shaking table tests were conducted to confirm the effect of the slope of the sloping ground on the dynamic behavior of group piles supporting the superstructure installed at the berm of the sloping sandy soil which is the asymmetric ground. The result shows that the acceleration of the pile cap and the superstructure decrease as the slope of the sloping ground increase, and the slope of the dynamic p-y curve of the pile decrease.

Correction of mandibular ramus height with frontal and lateral ramal inclinations in cephalograms and its effects on diagnostic accuracy of asymmetry (2차원 방사선 규격사진에서 하악골 상행지 고경의 보정분석에 관한 3차원 CT 영상 연구)

  • Hwang, Hyeon-Shik;Kim, Hyung-Min;Lee, Ki-Heon;Lim, Hoi-Jeong
    • The korean journal of orthodontics
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    • v.37 no.5
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    • pp.319-330
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    • 2007
  • Defining right and left side differences in mandibular ramus height is one of the key elements in the diagnosis of facial asymmetry. The purpose of the present study was to evaluate the effect of correction of ramus height with frontal and lateral ramal inclinations (FRI and LRI) in 2-dimensional cephalograms and observe how this affects the diagnostic accuracy of asymmetry. Methods: Frontal and lateral cephalograms were obtained in 40 individuals with chin deviation. FRI and LRI were measured on each side and ramus height measurement was corrected with these inclinations using Pythagorean's theorem. The results of diagnosis before and after correction on cephalograms were compared with the results in 3D CT images. Results: Both FRI and LRI showed greater values in the contralateral side than in the chin-deviated side and these contributed to an increase in the right and left side ramus height differences. After comparison of diagnostic results before and after correction on cephalograms with the results on 3D CT images, the sensitivity increased significantly (from 74 to 94 %) whereas the specificity decreased (from 44 to 22 %). Overall accuracy increased from 68 to 78 % with the correction using FRI and LRI. Conclusions: The results of the present study indicate that correction of ramus height with FRI and LRI is useful for an accurate diagnosis of facial asymmetry on frontal cephalograms.

Lateral Earth Pressure with The Shape of Narrow Space with Backfill (좁은 공간의 형상에 따른 되메움 토압에 관한 연구)

  • Huh, Kyung-Han
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.1
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    • pp.89-96
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    • 2008
  • The study, with regard to unsymmetrically inclined backfilled wall, was intended to estimate the lateral earth pressure, develop the equation for lateral earth pressure and eventually identify the mutual behavior, based on the modified Kellogg theory, while changing the width between the walls, wall angle, relative density and wall friction angle. To verify the geostatic pressure obtained from the study, the results in the wake of 62 kinds of model tests performed were compared and evaluated with the behaviors based on theoretical equations. As a result, the wall inclination angle was found to be the factors affecting the earth pressure the most, when both walls were inclined unsymmetrically. And the narrower the backfill space and the larger the wall inclination angle to the horizontal level, the greater the effect of the wall friction. The equation considering the wall friction reaction indicated the value, which was closer to the actually-measured earth pressure, and when the width between the warts was narrow, the arching effect appeared to be great, thereby indicating the difference between the measured earth pressure, theoretically calculated earth pressure and the geostatic pressure proved to be insignificant.

Posteroanterior cephalometric study of frontal ramal inclination in chin-deviated individuals (이부편위자의 하악골상행지 경사에 관한 정모두부방사선학적 연구)

  • Eun, Chun-Sun;Hwang, Hyeon-Shik
    • The korean journal of orthodontics
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    • v.36 no.5
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    • pp.380-387
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    • 2006
  • Objective: The purpose of this study was to compare the right and left differences of frontal ramal inclination in chin-deviated individuals. Methods: Thirty adult patients with clinically apparent chin deviation were selected as the chin-deviated group, and 30 adult patients with symmetric faces were selected as the control group. On the posteroanterior cephalograms, the frontal ramal inclination was measured, and the right and left differences were compared and analyzed. Results: While the control group did not show right and left differences of frontal ramal inclinations, the chin-deviated individuals showed right and left differences of frontal ramal inclination. In chin-deviated individuals, the frontal ramal inclinations of the non-deviated side were statistically greater than those of the deviated side. The right and left differences of frontal ramal inclinations, with menton deviation and the right and left differences of maxillary heights showed statistically significant correlation. Conclusion: We conclude that the frontal ramal inclinations should be considered in the diagnosis of facial asymmetry.

Analyses of Dipole-Dipole IP Responses over Dipping Structures (경사구조에 대한 쌍극자 IP 응답의 해석)

  • Kim, Hee Joon
    • Economic and Environmental Geology
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    • v.17 no.1
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    • pp.49-55
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    • 1984
  • This paper describes three-dimensional (3-D) standard curves for conductive dipping buried bodies in induced polarization (IP) method. Dipole-dipole IP responses for the dipping bodies are calculated by the numerical modeling technique using an integral equation solution. Dip angles of the bodies are 0, 20, 45, 70 and 90 degrees, respectively. The horizontal (0-degree dip) and vertical (90-degree dip) bodies produce symmetrical patterns of IP responses. The dipping bodies of 20, 45 and 70 degrees, however, produce asymmertical patterns, with the highest IP contours dipping in the direction opposite to the bodies in pseudo-sections. The most remarkable asymmetrical pattern appears in the model of 20-degree dip. It is difficult to distinguish the body of 70-degree dip from that of 90-degree dip on the basis of dipole-dipole IP data. The IP pattern in pseudo-sections varies when the line moves away from the center of the body along strike, with the anomaly deeper and smaller in amplitude. IP maps seem to be more useful than IP pseudo-sections in predicting the location of target.

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The Comparison on Resistance Performance and Running Attitude of Asymmetric Catamaran Changing Angle of Inclination of Tunnel Stern Exit Region (비대칭 고속 쌍동선의 선미터널 출구영역의 경사각 변화에 따른 저항성능 및 항주자세 분석)

  • Kim, Sang-Won;Seo, Kwang-Cheol;Cho, Dea-Hwan;Kim, Byung-Jae;Lee, Gyeong-Woo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2017.11a
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    • pp.232-233
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    • 2017
  • In this research, tunnel stern was applied on the asymmetric high-speed catamaran to evaluate vessel's hydrodynamic performance by numerical method, and the tunnel stern types are distinguished by angle of inclination of tunnel exit region into 3cases ($0^{\circ}$, $3^{\circ}$ and $6^{\circ}$). Consequently, it is confirmed that the total resistances of tunnel stern which have $0^{\circ}$ of inclination are lower about 4.8-17.9% than the bare hull in the wide speed range, but those of $3^{\circ}$ and $6^{\circ}$ of inclination tunnel stern are higher than bare hull about 5-14% and 5-29%, respectively. On the other hand, trim angles of $0^{\circ}$ of inclination tunnel stern show similar trend with those of bare hull in whole ranges of FnV but those of $3^{\circ}$ and $6^{\circ}$ of inclination tunnel stern are stabilized and declined respectively after FnV=1.54. These phenomena indicated that increasing angle of inclination of tunnel exit region had negative influence on resistance performance, however, it could make vessel's operation performance better than bare hull.

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