• Title/Summary/Keyword: Value Inclination

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Analysis of the crack propagation rules and regional damage characteristics of rock specimens

  • Li, Yangyang;Xu, Yadong;Zhang, Shichuan;Fan, Jing;Du, Guobin;Su, Lu;Fu, Guangsheng
    • Geomechanics and Engineering
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    • v.24 no.3
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    • pp.215-226
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    • 2021
  • To study the evolution mechanism of cracks in rocks with multiple defects, rock-like samples with multiple defects, such as strip-shaped through-going cracks and cavity groups, are used, and the crack propagation law and changes in AE (acoustic emission) and strain of cavity groups under different inclination angles are studied. According to the test results, an increase in the cavity group inclination angle can facilitate the initial damage degree of the rock and weaken the crack initiation stress; the initial crack initiation direction is approximately 90°, and the extension angle is approximately 75~90° from the strip-shaped through-going cracks; thus, the relationship between crack development and cavity group initiation strengthens. The specific performance is as follows: when the initiation angle is 30°, the cracks between the cavities in the cavity group develop relatively independently along the parallel direction of the external load; when the angle is 75°, the cracks between the cavities in the cavity group can interpenetrate, and slip can occur along the inclination of the cavity group under the action of the shear mechanism rupture. With the increase in the inclination angle of the cavity group, the AE energy fluctuation frequency at the peak stress increases, and the stress drop is obvious. The larger the cavity group inclination angle is, the more obvious the energy accumulation and the more severe the rock damage; when the cavity group angle is 30° or 75°, the peak strain of the local area below the strip-shaped through-going fracture plane is approximately three times that when the cavity group angle is 45° and 60°, indicating that cracks are easily generated in the local area monitored by the strain gauge at this angle, and the further development of the cracks weakens the strength of the rock, thereby increasing the probability of major engineering quality damage. The research results will have important reference value for hazard prevention in underground engineering projects through rock with natural and artificial defects, including tunnels and air-raid shelters.

Study on the Characteristics of Shear Strength on the Weathered Granite Soil Slope in Accordance with the Rainfall (강우에 따른 화강암질 풍화토 사면의 전단강도 특성에 관한 연구)

  • Shim Tae-Sup;Kim Sun-Hak;Ki Wan-Seo;Joo Seung-Wan
    • The Journal of Engineering Geology
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    • v.14 no.4 s.41
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    • pp.349-360
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    • 2004
  • This study calculated the pore water pressure, the depth of seepage, the constant of the strength in accordance with the slope inclination and the rainfall intensity over the slope built by the weathered granite soil (SP, SM). And, the change of the shear strength in accordance with the rainfall has been compared and analyzed by applying the shear strength formula of the unsaturated soil. As a result, the rainfall intensity is stronger and the slope inclination is gentler the seepage speed in accordance with the rainfall became faster proportionally. As a result of comparing and analyzing both the theoretical value of Lumb and the actual value of the model, it can be said that the actual value is faster. Since SM shows the bigger shear strength than SP, it can also be said that as the granules increase, the coefficient of permeability becomes smaller; and as the seepage rate became smaller, it affects the seepage speed. Likewise, the shear strength within the slope displays the smallest shear strength at the inclination of 1:1.5 the reason of its decrease turned out that it was due to the increase of the pore water pressure.

A Negative Effect of Animation Character in Mass Culture of Korea (한국의 대중문화에 Animation Character가 미치는 부정적인 영향)

  • 김홍산;신정숙
    • Archives of design research
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    • v.14 no.2
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    • pp.147-154
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    • 2001
  • The Animation Character is high value-added industry in an aspect of economic value. Because Animation Character creates various synergic effects. First and most importantly, the value of animation character is role of communicator in mass culture. The diverse personality and behavior of Animation character affects masses's a way of thinking and act. But the personality and behavior of Animation character express an extreme inclination, for the most part. And presentation of role's model that is necessary for maintenance and continuance of mass society is Auctioning wrongfully.

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Static Characteristics and Design of Hemispherical Aerodynamic Bearing (반구형 공기동압베어링의 정적 특성 및 설계)

  • 김승곤;김준영;최환영
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1997.10a
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    • pp.217-224
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    • 1997
  • Static characteristics of hemispherical aerodynamic bearing is studied theoretically. In this paper nonlinear equation of second order considering compressibility and slip effect of air is calculated by Newton-Raphson method. Results indicate that axial load capacity has maximum value when the inclination angle of groove is about 30$\circ$, the ratio of groove clearance to ridge clearance is two. We also present the design method of hemispherical Aerodynamic bearing based on it's load capacity taking into account manufacturing and assembling viewpoint.

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An anatomical study on the mandibular medial surface by CBCT analysis for safer implant placement (안전한 임플란트 식립을 위한 하악골 내측면의 CBCT를 이용한 해부학적 연구)

  • Lee, Jung-Kyo;Kim, Yeo-Gab
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.37 no.1
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    • pp.43-48
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    • 2011
  • Introduction: This study examined the anatomical morphology of the medial surface of the posterior mandible using 3-dimensional cone-beam computed tomography (CT) images to reduce the number of complications related to dental implant placement. Materials and Methods: Fifty patients were enrolled in this study with an average age (${\pm}$standard deviation) of 44.28 (${\pm}13.05$). On the coronal views cone-beam CT of the first molars, the distance between the top of the canal and alveolar crest vertical distance (VD), the distance between the upper-most point of the canal and the point perpendicular to the lingual cortical margin of the mandible lingual distance (LD), the location of the starting point of VD for reducing from the vertical reference line (VD point), and the inclination of the mandibular medial surface (lingual inclination) were measured, and a statistical evaluation was performed using SPSS for Windows version 15.0. Results: The mean VD0 was $16.91{\pm}2.47\;mm$ and VDx decreased with increasing x value. The mean LD was $5.27{\pm}1.36\;mm$. The VD began to decrease at the mean location of $6.12{\pm}0.96\;mm$ from the vertical reference line. The mean lingual inclination was $1.52{\pm}0.72^{\circ}$. Conclusion: These results will assist in the accurate placement of dental implants and the reduction of complications, particularly in the case of preoperative implant planning using only 2-dimensional imaging methods. (ex. panoramic radiography)

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.

The Study on Pressure Oscillation and Heat Transfer Characteristics of Oscillating Capillary Tube Heat Pipe Using Mixed Working Fluid (혼합 작동 유체를 이용한 진동 세관형 히트 파이프의 압력 진동과 열전달 특성에 관한 연구)

  • Jeong, Hyeon-Seok;Kim, Jeong-Hun;Kim, Ju-Won;Kim, Jong-Su
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.2
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    • pp.318-327
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    • 2002
  • In this paper, heat transfer and pressure oscillation characteristics on oscillating capillary tube heat pipe(OCHP) according to input heat flux, mixture ratio of working fluid and inclination angle were investigated and were compared single working fluid(R-142b) with binary mixture working fluid(R-142b-Ethano1). OCHP was made to serpentine structure of loop type with 10 turns by drilling the channels of length 220mm, width 1.5mm, and depth 1.5mm on the surface of brass plate. In this study, R-l42b and R-l42b-Ethanol were used as working fluids, the charging ratio of working fluids was 40(vol.%), the input heat flux to evaporating section was changed from 0.3W/㎠ to 1.8W/㎠, and mixture ratio of working fluid was R(100%), R(95%)-E(5%), R(90%)-E(10%), and R(85%)-E(15%). From the experimental results, it was found that the effective thermal conductivity of single working fluid was better than that of binary mixture working fluid. But, in case of binary mixture working fluid, critical heat flux was higher than that of single working fluid. And, the higher the mixture ratios of working fluid, the lower heat transfer performance. In case of pressure oscillation, as the inclination angle was lower, pressure wave was more irregular. These phenomena were more serious when the working fluid was binary mixture. Besides, when mixture ratio was higher, saturated pressure was increased, more irregular wave was observed and the mean amplitude was increased. For the same input heat flux, inclination angle and charging ratio, when pressure oscillation has sinusoidal wave, mean amplitude was small, and saturated pressure was low value, the heat transfer was excellent.

A comparative study to measure the sagittal condylar inclination using mechanical articulator, virtual articulator and jaw tracking device

  • Liya Ma;Fei Liu;Jiansong Mei;Jiarui Chao;Zhenyu Wang;Jiefei Shen
    • The Journal of Advanced Prosthodontics
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    • v.15 no.1
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    • pp.11-21
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    • 2023
  • PURPOSE. To compare the sagittal condylar inclination (SCI) in dentate individuals measured by the different methods with mechanical articulator (MA), virtual articulator (VA), and a jaw tracking device (JTD) system. MATERIALS AND METHODS. A total of 22 healthy dentate participants were enrolled in this study. For MA workflow, the SCI was obtained by a semi-adjustable articulator with protrusive interocclusal records. The SCI was also set on a VA by aligning intraoral scan (IOS) with cone beam computed tomography (CBCT) and facial scan (FS), respectively. These virtual workflows were conducted in a dental design software, namely VAIOS-CBCT and VAIOS-FS. Meanwhile, a JTD system was also utilized to perform the measurement. Intraclass correlation was used to assess the repeatability within workflows. The bilateral SCI values were compared by Wilcoxon matched-pairs signed rank test for each workflow, and Kruskal-Wallis test and post hoc p-value Bonferroni correction were used to compare the differences among four workflows. The agreement of VAIOS-CBCT, VAIOS-FS, and JTD compared with MA was evaluated by Bland-Altman analysis. RESULTS. Intraclass correlation of the SCI revealed a high degree of repeatability for each workflow. There were no significant differences between the left and right sides (P > .05), except for VAIOS-CBCT (P = .028). Significant differences were not found between MA and VAIOS-FS (P > .05). Bland-Altman plots indicated VAIOS-CBCT, VAIOS-FS, and JTD were considered to substitute MA with high 95% limits of agreement. CONCLUSION. The workflow of VAIOS-FS provided an alternative approach to measure the SCI compared with MA.

The study of the relationship among make-up attitude, body-related value, and clothing behavior (화장태도, 신체가치, 의복행동 간의 관계 연구)

  • Chung, Mi Sil
    • Korean Journal of Human Ecology
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    • v.22 no.4
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    • pp.677-691
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    • 2013
  • The purpose of this study was to examine the influence of make-up attitude and body-related value on clothing behavior. The subjects were 315 female college students in Gyeongsang provinces. The obtained data were analyzed by reliability analysis, factor analysis, cluster analysis, one-way ANOVA, Duncan's multiple range test, correlation analysis, multiple regression analysis and t-test. The major results of this study were as follows: First, four factors of make-up attitude were identified: pursuit of confidence, sociality, self-satisfaction, and positive image. Second, the subjects were categorized into three different types of groups according to make-up attitude and body-related value, respectively: high involvement type, low involvement type, and middle involvement type. Third, there was significant difference among three groups which were segmented by each make-up attitude and body-related value on clothing behaviors (sexual attractiveness, showing off, body-enhancement). Fourth, a significant positive correlation was found among four factors of make-up attitude and body operatability with clothing behaviors. Fifth, the important variables that affected the clothing behaviors were pursuit of confidence, self-satisfaction, and positive image of make-up attitude. Sixth, body-inclination significantly influenced sexual attractiveness of clothing behavior, whereas body-related value, unlike make-up attitude, only had marginal influence.

Negative GM and Ship's Transverse Stability (음의 복원성과 선박의 횡경사)

  • You, Su-Yeon;Yang, Hyoung-Seon;Jung, Dae-Deug
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2016.05a
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    • pp.108-109
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    • 2016
  • It is very important to fully understand the concepts, causes and corrections of ship's transverse inclination which is classified into Heel, List and Loll. Particularly, it is presumed that some recent disaster at sea is related to negative GM developed by the loss of stability during sailing. In this study, actual 'Angle of Loll' is simulated by model-ship experiment and the result is compared with calculated value under same condition. Furthermore, how to distinguish Loll from List and the way to correct the 'Angle of Loll' for officers are described.

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