• Geomechanics and Engineering
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• v.35 no.4
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• pp.385-393
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• 2023

To analyze the consolidation with horizontal sand drains, the plane strain consolidation model under multi-ramp loading is established, and its corresponding analytical solution is derived by using the separation of variables method. The proposed solution is verified by the field measurement data and finite element results. Then, the effects of the loading mode and stress distribution on consolidation and dissipation of pore pressure are investigated. At the same time, the influence of hydraulic conductivity and thickness of sand blankets on soil consolidation are also analyzed. The results show that the loading mode has a significant effect on both the soil consolidation rate and generation-dissipation process of pore water pressure. In contrast, the influence of stress distribution on pore pressure dissipation is obvious, while its influence on soil consolidation rate is negligible. To guarantee the fully drained condition of the sand blanket, the ratio of hydraulic conductivity of the sand blanket to that of clay layer k_d/k_v should range from 1.0×10⁴ to 1.0×10⁶ with soil width varying from 100 m to 1000 m. A larger soil width correspondingly needs a greater value of kd/kv to make sure that the pore water can flow through the sand blanket smoothly with little resistance. When the soil width is relatively small (e.g., less than 100 m), the effect of thickness of the sand blanket on soil consolidation is insignificant. And its influence appears obvious gradually with the increase of the soil width.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.914-924
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• 2018

The purpose of this study is to provide the basic data for the shoulder strengthening exercise by analyzing the% MVIC of the muscle activity in the shoulder rotator cuff by the difference of the stance posture and the anatomical plane. 8male subjects were randomly assigned to perform the shoulder rotation exercise 10 times on the frontal plane, the horizontal plane, the sagittal plane and the two legs stance posture, the one leg stance posture, the lunge posture. Measured muscle activity of supraspinatus, infraspinatus, teres minor, anterior deltoid, rectus abdominis, erector supinea, pectoralis major, lattisimus dorsi during exercise. A repetitive one-way ANOVA was performed using the SPSS 22.0 statistical program. First, during the external rotation on the frontal plane, the erector spinea was higher in the lunge posture than in the two legs stance posture and the one leg stance posture, And during the internal rotation on the frontal plane, the muscle activity of suprapinatus was higher in one leg stance posture than in the two legs stance posture and more so in the lunge posture. Second, during the external rotation on the horizontal plane, the muscle activity of deltoid anterior was higher in the one legs stance posture and in the lunge posture than in the two legs stance posture, and during the internal rotation on the horizontal plane, the muscle activity of infraspinatus was higher in the lunge posture than in the two legs stance posture and one leg posture, and the muscle activity of pectoralis major was higher in two leg stance posture than in the one legs stance posture and more so in the lunge posture. Third, during the external rotation on the sagittal plane, muscle activity of rectus abdominis was higher one leg stance posture in the lunge posture than in two leg stance posture. During the internal rotation on the sagittal plane, muscle activity of supraspinatus was higher one leg stance posture in the lunge posture than in two leg stance posture. And muscle activity of infraspinatus was higher in the lunge posture than in two leg stance posture, one leg stance. And muscle activity of Rectus abdominis was higher in the lunge posture and one leg stance posture than in the two legs stance posture. And muscle activity of Erector spinea was higher in the two legs stance postur and lunge posture than in the one leg stance posture. In conclusion, the differences in stance and shoulder anatomy have different effects on the muscle activity of the shoulder rotator exercises, and this is expected to be a more positive exercise program when applied to the shoulder strengthening exercise program.

• Journal of the Korean Society of Clothing and Textiles
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• v.18 no.2
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• pp.252-262
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• 1994

As a means to get a better understanding of the kind of form changes to which is subject the neck of the men, in its aging process, several measurement recordings on a vertical and horizontal sections were carried. Subjects were young, middle aged and elder men (15 in their twenties, 11 in their forties and again 11 in their sixties) 1) The analysis of the meansurement results led us to distinguish 3 types of subjects according to the position of the their Adam's apple with regard to the horizontal plane containing their 7th cervical vertebrae point : clearly above (Type I), next to(Type II), clearly below(Type III). We found that young men correspond to the Type I and II, middle aged men to the Type ll and 111 and elder men only to the Type III. 2) The comparison of the horizontal sectional surface contained in the planes corresponding to the 4 points, shows a larger sectional surface for elder men in the Adam's apple plane, accompanied by a change of position of the Adam's apple forwards. As for the front neck point plane, the body sectiolial surface is larger in depth in elder men, without much change in breadth. And for the acromion point plane, we observed also an increase in depth, but with a decrease in breadth corresponding partially to the atrophy of the thoraric cage in eldermen.

• Proceedings of the KSRS Conference
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• v.1
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• pp.508-511
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• 2006

Generally, stereo pair images are necessary for 3D viewing. In the absence of quality stereo-pair images, it is possible to synthesize a stereo-mate suitable for 3D viewing with a single image and a depth-map. In remote sensing, DEM is usually used as a depth-map. In this paper, LiDAR data was used instead of DEM to make a stereo pair from a single aerial photo. Each LiDAR point was assigned a brightness value from the original single image by registration of the image and LiDAR data. And then, imaginary exposure station and image plane were assumed. Finally, LiDAR points with already-assigned brightness values were back-projected to the imaginary plane for synthesis of a stereo-mate. The imaginary exposure station and image plane were determined to have only a horizontal shift from the original image's exposure station and plane. As a result, the stereo-mate synthesized in this paper fulfilled epipolar geometry and yielded easily-perceivable 3D viewing effect together with the original image. The 3D viewing effect was tested with anaglyph at the end.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.2 s.173
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• pp.496-505
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• 2000

A semi-infinite parallel crack propagated with constant velocity in two bonded anisotropic strip under anti-plane clamped displacement is analyzed. Using Fourier integral transform a Wiener-Hopf equation is derived. By solving this equation the asymptotic stress and displacement fields near the crack tip are determined, where the results give the more general expression applicable to the extent of the anisotropic material having one plane of elastic symmetry for the parallel crack. The dynamic stress intensity factor and energy release rate are also obtained as a closed form, which are the results applicable to the problem both of dynamic and static crack under the same geometry as this study. The stress intensity factor approaches zero at the critical crack velocity which is less than the shear wave velocity, but in typical case of isotropic or orthotropic material agrees with the velocity of shear wave. Also a circular shear stress around crack tip is considered, from which the stress is shown to be approximately symmetric about the horizontal axis. Referring to the maximum stress criteria, it could be shown that a brenched crack is formed by crack growth as crack velocity increases.

• Geomechanics and Engineering
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• v.29 no.2
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• pp.145-154
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• 2022

Complex geological conditions have a great influence on the mining of coalbed methane (CBM), which affects the extraction efficiency of CBM. This investigation analyzed the complicated geological conditions in the Liujia CBM block of Fuxin. A geological model of heterogeneities CBM reservoirs was established to study the influence of strike direction of igneous rocks and fault structures on horizontal well layout. Subsequently, the dual-porosity and dual-permeability mathematical model was established, which considers the dynamic changes of porosity and permeability caused by gas adsorption, desorption, pressure change. The results show that the production curve is in good agreement with the actual by considering gas seepage in matrix pores in the model. Complicated geological structures affect the pressure expansion of horizontal wells, especially, the closer to the fault structure, the more significant the effect, the slower the pressure drop, and the smaller the desorption area. When the wellbore extends to the fault, the pressure expansion is blocked by the fault and the productivity is reduced. In the study area, the optimal distance to the fault is 70 m. When the horizontal wellbore is perpendicular to the direction of coal seam igneous rock, the productivity is higher than that of parallel igneous rock, and the horizontal well bore should be perpendicular to the cleat direction. However, the well length is limited due to the dense distribution of igneous rocks in the Liujia CBM block. Therefore, the horizontal well pumping in the study area should be arranged along the direction of igneous rock and parallel plane cleats. It is found that the larger the area surrounded by igneous rock, the more favorable the productivity. In summary, the reasonable layout of horizontal wells should make full use of the advantages of igneous rock, faults and other complex geological conditions to achieve the goal of high and stable production.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2530-2544
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• 2018

In this paper, we propose an enhanced LiDAR-camera calibration method that extracts the marker plane from 3D point cloud information. In previous work, we estimated the straight line of each board to obtain the vertex. However, the errors in the point information in relation to the z axis were not considered. These errors are caused by the effects of user selection on the board border. Because of the nature of LiDAR, the point information is separated in the horizontal direction, causing the approximated model of the straight line to be erroneous. In the proposed work, we obtain each vertex by estimating a rectangle from a plane rather than obtaining a point from each straight line in order to obtain a vertex more precisely than the previous study. The advantage of using planes is that it is easier to select the area, and the most point information on the board is available. We demonstrated through experiments that the proposed method could be used to obtain more accurate results compared to the performance of the previous method.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.5
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• pp.372-382
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• 2002

As the most of dentofacial deformity patients indicated to orthognathic surgery have strong desire for esthetic improvement as well as functional improvement, ideal esthetic evaluation should be made at surgical prediction. Lateral cephalographs has been commonly used for surgical prediction, however, remarkable discrepancy between esthetic viewpoint by simple looking and analysis on lateral cephalographs often found on evaluation of sagittal position of the upper and lower jaws especially in cases of mandibular prognathism of Koreans. In these cases, we have been employed Esthetic NaP(ENaP)-line for corrective evaluation and ideal surgical prediction on lateral cephalographs, but the efficacy of ENaP-line has not been evaluated. This is a study on efficacy of ENaP-line for orthognathic surgery of Korean mandibular prognathism. 170 Korean patients who had been diagnosed as mandibular prognathism and planned for orthognathic surgery at Department of Oral and Maxillofacial Surgery, College of Dentistry, Yonsei University during last 10 years are studied. The obtained results are as followings; among 170 patients of mandibular prognathism, 132 patients(77.6%) had not discrepancy in evaluation of sagittal position of the maxilla between cephalometric and esthetic evaluation(they are classified as Group I), however, 38 patients(22.4%) had definite discrepancy(they are classified as Group II). ENaP-line was employed in all cephalometric analysis of Group II. The proportions of male and female were similar in both Groups. Sixteen vertical reference lines perpendicular to 16 horizontal reference lines were obtained as followings; Each of the representative degree of ${\angle}SN/AFH$, ${\angle}SN/CFH$ and ${\angle}AFH/CFH$ obtained at Group I was applied to SN plane, AFH plane and CFH plane of Group II each other, and so 16 horizontal reference lines could be obtained individually according to each of the applied degree to each plane. And then their reliability to coincide with ENaP-line of Group II was evaluated. A vertical reference line perpendicular to a horizontal line made by application of the representative degree of ${\angle}$AFH/CFH in Group I to AFH line in Group II had the most highest coincidence with ENaP-line of Group II, however, its agreement was 42% in male and 47% in female. From this results, the rest of them should be determined their corrective jaw position definitely depend on

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.3
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• pp.142-149
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• 2006

A PIV(Particle Image Velocimetry) was applied to measure in-cylinder velocity field according to inlet valve angle during intake stroke. Two engines, one is conventional DOHC 4 valve and the other is narrow valve angle, were used to compare real intake flow. The results show that the intake flow pattern of conventional engine is more complicated than that of narrow angle one in horizontal plane and the vertical component of in-cylinder flow is rapidly decayed at the end stage of intake. On the other hand, the flow pattern of narrow angle one is relatively well arranged in horizontal plane and the vertical velocity component remains so strongly that forms large-scale strong tumble. Two engines also form commonly three tumble; two are small and bellow the intake valve and one is large-scale. The center of large scale tumble moves to bottom of cylinder as the vertical velocity increases.

• The Journal of the Acoustical Society of Korea
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• v.41 no.4
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• pp.397-409
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• 2022

A model is developed for the calculation of sea surface generated ambient noise in the range dependent ocean environment. The sources are located in the horizontal plane all around and their depths are at the near-surface. The receiver array is located in the range dependent ocean waveguide. One-way coupled mode method is used to model the acoustic propagation between the sources and receiver in the range dependent waveguide, and the cross spectral density matrix of noise is derived. In simulation, noise intensity, beamforming result and coherence function are calculated from the cross spectral density matrix. These results are compared with those in the range independent environment. The modeling result shows the effect of the vertical directionality and asymmetry characteristics of the horizontal plane.