• Title/Summary/Keyword: Stability Area

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A case study of large-scale slope failure in Granite - Andesite contact area (화강암-안산암 접촉부 대규모 사면의 붕괴 사례 연구)

  • 이수곤;양홍석;황의성
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.503-508
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    • 2003
  • In this study, we peformed ahead a field geological investigation, boring investigation for slope stability analysis in large scale slope failure area. But the geological stratum was not clearly grasped, because ground was very disturbed by large scale Granite intrusion. Furthermore, the existing test data was not pertinent to the large scale Granite intrusion site like here. Therefore, various kind of field test were performed to grasp clearly for geological stratum. And the results of back analysis, various kind tests used to slope stability analysis.

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Stability Analysis ofn HTS Current Lead with Constant Safety Factor (안전율이 일정한 초전도 전류도입선의 안정성해석)

  • Seol, Seoung-Yun
    • Progress in Superconductivity and Cryogenics
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    • v.2 no.2
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    • pp.15-19
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    • 2000
  • The stability of variable cross-sectional area HTS current lead is considered. The cross-sectional area is varied to have a constant safety factor which is defined as the ratio of operating current and critical current of superconductor. As the constant area HTS lead, the variable cross-sectional area HTS lead also has three steady states above the bifurcation point and only one steady state below the bifurcation point. The temperature profiles and current sharing ratios for each steady state are calculated. The heat dissipation into cryogenic system for super-conducting, intermediate, and upper states are compared. For Bi-2333 sheathed with silver-gold alloy 2m length of current lead, and the maximum temperature of upper state seems to be burn-out free below 5m length.

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A Study of the Changes in Dress Wearers' Images in Relationto the Changes in the Size and Area Ratio of Polka Dots Relative to Coloration (색상대비 물방울무늬의 크기와 면적비 변화에 따른 원피스 드레스 착용자의 이미지 연구)

  • Kim, Sun-Mi;Jeong, Su-Jin
    • Journal of the Korean Society of Costume
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    • v.58 no.6
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    • pp.54-68
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    • 2008
  • The purpose of this study is to investigate the effect of dot pattern size(0.8, 1.8, 2.5, 5, 8), color combination(BG/R, Y/B), area-ratio on image formation. Sets of stimulus and response scales(7 point semantic) were used as experimental materials. The stimuli were 20 color pictures manipulated with the combination of dot pattern size, color combination, and area-ratio using computer simulation. The subjects were 240 female undergraduates living in Gyeongnam-do. Image factor of the stimulus was composed of 5 different components, visibility, attractiveness, cuteness, stability and high class image. In the cuteness, color combination, dot pattern size showed independent effect. In the stability, area-ratio, dot pattern size showed independent effect. Interaction effects of color and area-ratio combination was significant on cuteness. For visibility image 8cm yellow dot/blue background, for attractiveness image BG/R coloration, for cuteness image Y/B coloration and for stability image 0.8cm yellow dot/blue background were effective. According to the variation of dot pattern size, color combination and area-ratio, it was investigated that the images for a dress wearer were expressed diversely, were shown differently in image dimensions, and could be produced to different images.

Analysis of stability control and the adapted ways for building tunnel anchors and a down-passing tunnel

  • Xiaohan Zhou;Xinrong Liu;Yu Xiao;Ninghui Liang;Yangyang Yang;Yafeng Han;Zhongping Yang
    • Geomechanics and Engineering
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    • v.35 no.4
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    • pp.395-409
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    • 2023
  • Long-span suspension bridges have tunnel anchor systems to maintain stable cables. More investigations are required to determine how closely tunnel excavation beneath the tunnel anchor impacts the stability of the tunnel anchor. In order to investigate the impact of the adjacent tunnel's excavation on the stability of the tunnel anchor, a large-span suspension bridge tunnel anchor is utilised as an example in a three-dimensional numerical simulation approach. In order to explore the deformation control mechanism, orthogonal tests are employed to pinpoint the major impacting elements. The construction of an advanced pipe shed, strengthening the primary support. Moreover, according to the findings the grouting reinforcement of the surrounding rock, have a significant control effect on the settlement of the tunnel vault and plug body. However, reducing the lag distance of the secondary lining does not have such big influence. The greatest way to control tunnel vault settling is to use the grout reinforcement, which increases the bearing capacity and strength of the surrounding rock. This greatly minimizes the size of the tunnel excavation disturbance area. Advanced pipe shed can not only increase the surrounding rock's bearing capacity at the pipe shed, but can also prevent the tunnel vault from connecting with the disturbance area at the bottom of the anchorage tunnel, reduce the range of shear failure area outside the anchorage tunnel, and have the best impact on the plug body's settlement control.

Analysis of Rock Slope Stability by Using GIS in Mt. Keumsu Area (지구정보시스템을 이용한 금수산일대의 암반사면 안정성 평가)

  • 배현철
    • Economic and Environmental Geology
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    • v.33 no.1
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    • pp.77-88
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    • 2000
  • The goal of this study is to assess the spatial distribution of natural slopes and cutting slopes under would-be development. For this goal, a quantitative slope stability analysis method using GIS integrated with a computer program was developed. Through field investigations, the discontinuity parameters were collected such as orientation of discontinuity, persistence, spacing, JRC, JCS, and water depth. The distributions were interpolated from the ordinary kriging method in ARC/INFO GIS after variogram analysis. The layers showing all parameters needed for limit equilibrium analysis were constructed. The final layer using GIS works composed of 162,352 polygons, that is, unit slopes. The rock slope stability analysis program was coded by C++ language. This program can calculate geometrical vectors related to rock block failures using input orientation data and direction and dimension of strength to occur failure. Also, this can calculate shear strength of joints through empirical equations and quantitative factors of safety. This methodology was applied to the study area which is located in Jaecheon city and Danyang-gun of the northeastern Keumsu is about 135$km^2$. As a result, the study area was entirely stable but unstable, that is, factor of safety less than 1.0dominantly at the slopes near Keumsil, Daejangri, Keumsungmyun and Sojugol, Mt. Dongsan, Juksongmyun by the natural slope stability analysis. Assuming the cutting slope showing the same direction immediate, and quantitative analysis of factors of safety for a regional area could be conducted through GIS integrated with a computer program of limit equilibrium.

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Immediate Effects of Abdominal Pressure Belt on Limited of Stability and Gait Parameter in Patients after Chronic Stroke: one-group pretest-posttest design (복부압박벨트가 만성 뇌졸중 환자의 균형 및 보행에 즉각적으로 미치는 융복합적 영향)

  • Park, Shin-Jun;Cho, Kyun-Hee
    • Journal of the Korea Convergence Society
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    • v.11 no.4
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    • pp.63-69
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    • 2020
  • This study was conducted to investigate the immediate effects of abdominal pressure blet on limited of stability and gait parameter in patients after stroke. Thirty stroke patients were recruited to measured pre and post wearing the abdominal pressure belt. The assessment measured limited of stability and spatiotemporal gait parameter. This study result were significantly increase in paretic side area, non-paretic side area, forward side area, backward side area (p<.05) and cadence, gait velocity, stride length (p<.05). This study found that abdominal pressure belt had an immediate effect on improving balance and gait function in stroke patients. Future studies require studies of efficient abdominal pressure levels and intervention periods to improve the balance and walking function of stroke patient.

Time-Series Interferometric Synthetic Aperture Radar Based on Permanent Scatterers Used to Analyze Ground Stability Near a Deep Underground Expressway Under Construction in Busan, South Korea (고정산란체 기반 시계열 영상레이더 간섭기법을 활용한 부산 대심도 지하 고속화도로 건설 구간의 지반 안정성 분석)

  • Taewook Kim;Hyangsun Han;Siung Lee;Woo-Seok Kim
    • The Journal of Engineering Geology
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    • v.33 no.4
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    • pp.689-699
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    • 2023
  • Assessing ground stability is critical to the construction of underground transportation infrastructure. Surface displacement is a key indicator of ground stability, and can be measured using interferometric synthetic aperture radar (InSAR). This study measured time-series surface displacement using permanent scatterer InSAR applied to Sentinel-1 SAR images acquired from January 2017 to June 2023 for the area around a deep underground expressway under construction to connect Mandeok-dong and Centum City in Busan, South Korea. Regions of seasonal subsidence and uplift were identified, as were regions with severe subsidence after summer 2022. To evaluate stability of the ground in the construction area, the mean displacement velocity, final surface displacement, cumulative surface displacement, and difference between minimum and maximum surface displacement were analyzed. Considering the time-series surface displacement characteristics of the study area, the difference between minimum and maximum surface displacement since June 2022 was found to be the most suitable parameter for evaluating ground stability. The results identified highly unstable ground in the construction area as being to the north of the mid-lower reaches of the Oncheon-cheon River and to the west of the Suyeong River at the point where both rivers meet, with the difference between minimum and maximum surface displacement of 40~60 mm.

The Association between Cross-section of Lumbar Regional Muscle analyzed by MRI and Stability, Center of Pressure assessed by Tetrax (요통 환자의 요추 주변 근육 단면적과 신체안정성(Stability), 체중심(Center of Pressure)과의 관련성 : 동적평형검사(Tetrax)를 중심으로)

  • Seong, Ik-Hyun;Lee, Kap-Soo;Jung, Jae Hoon;Kim, Won-Woo;Cho, Chang-Young;Choi, Chul-Woo;Ha, In-Hyuk
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.8 no.2
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    • pp.39-46
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    • 2013
  • Objectives : To identify the association between cross-sectional area of lumbar regional muscle and stability(ST), center of pressure(COP) assessed by tetrax. Methods : Patients(n=55) who had taken L-SPINE MRI and Tetrax(Sunlight, Israel) were analyzed retrospectively. To evaluate the cross-sectional area of lumbar regional muscle, L-SPINE MRI was used. Data of ST, COP were accumulated by using dynamic equilibrium analysis by Tetrax. Of the lumbar regional muscles, the Psoas muscles and the Paraspinalis muscles were examined. Using Pearson correlation, we analyzed COP, ST and the difference between the cross-sectional area of lumbar regional muscles. Results : The variance of cross-sectional area of both sides of Psoas muscle and COP had moderate positive correlation(r=0.621). Between variance of cross-sectional area of both sides of Paraspinalis and lumbar regional muscle and COP there was low positive correlation(r=0.287, r=0.329) ST also had low correlation with variance of cross-sectional area of both sides of Psoas muscle. Conclusion : The variance of cross-sectional area between both sides of Psoas muscle had moderate correlation with COP.

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A Study on Changes in Appendage Design for Improvement of Dynamic Stability of Manta-type Unmanned Undersea Vehicle (Manta형 무인잠수정의 동안정성 향상을 위한 부가물의 설계 변경에 관한 연구)

  • Bae, Jun-Young;Sohn, Kyoung-Ho;Kwon, Hyeong-Ki;Lee, Seung-Keon
    • Journal of the Society of Naval Architects of Korea
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    • v.44 no.3 s.153
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    • pp.323-331
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    • 2007
  • Proposed Manta-type Unmanned Undersea Vehicle(UUV) turned out to have the tendency of dynamic instability in vertical plane, and moreover to have that of so strong dynamic stability in horizontal plane as to cause another problem in turning motion due to negative value of sway damping lever. The authors discussed the changes in appendage design for improvement of dynamic stability of UUV in vertical and horizontal planes. As a result, the dynamic stability in vertical plane was improved by increasing the area of horizontal stern planes. and the dynamic stability in horizontal plane was also improved by removal of lower vertical plate and by adjusting the area and position of upper vertical plate simultaneously.

A Study on the Effect of Rudder Area with Reference to Changes in Span Distance on Course Stability of a Ship (타의 스팬길이에 따른 면적 변화가 침로안정성에 미치는 영향에 관한 연구)

  • Sohn, K.H.;Lee, G.W.;Kim, H.S.;Kim, Y.S.;Ha, M.K.
    • Journal of the Society of Naval Architects of Korea
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    • v.33 no.4
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    • pp.1-14
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    • 1996
  • Especially in the case of a full form ship, the stability on course can be considered to become severest among 4 items of criteria in Interim Standards for Ship Maneuverability adopted by IMO in 1993. The purpose of this study is to find some ideas for the improvement of stability on course through changes in rudder area with reference to span distance. In this paper, we established the formula on the relation between the experimental constants relevant to rudder normal force and hydrodynamic derivatives of hull-propeller-rudder system. We carried out various kinds of captive model test relevant to rudder normal force etc., and evaluated hydrodynamic derivatives of hull-propeller-rudder system, and analyzed the stability on course with the parameter of changes in rudder area. Furthermore, we also discussed effects of changes in rudder area on maneuvering performance including stability on course, based on computer simulation. As a result, it is clarified that there is a possibility that stability on course may become bad through an increase of rudder area. The reason for the bad stability on course is that the void space between the upper edge of rudder and the lower part of stern overhang decreases. This space change exerts a great influence on straightening coefficient of incoming flow to rudder in maneuvering motion, which has close relation to stability on course.

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