• Title/Summary/Keyword: inclination test

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Estimation of in-situ Stresses and the Effect of a Preexisting Inclined Fracture by Hydraulic Fracturing (수압파쇄를 이용한 초기지압측정과 기존경사균열의 영향)

  • 신중호;신희순;최성웅;이희근
    • Tunnel and Underground Space
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    • v.4 no.1
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    • pp.55-62
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    • 1994
  • The hydraulic fracturing in a field site was performed for the measurement of in-situ stresses. For the estimation of the effect of a preexisting inclined fracture, the test on a preexisting fracture zone was also conducted. From the measurements at three shallow depths, the ratios of max. to min. horizontal stress showed the range of 1.19-1.56 and the K values showed the range of 2.62-3.86. In case of a preexisting fracture with the inclination of 15 degrees, the stresses calculated as upper bound values by considering it. It seemed from this that the inclination less than 15 degrees had small effect on the stress calculation.

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Experimental and numerical analysis of mixed mode I/III fracture of sandstone using three-point bending specimens

  • Li, Yifan;Dong, Shiming;Pavier, Martyn J.
    • Structural Engineering and Mechanics
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    • v.76 no.6
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    • pp.725-736
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    • 2020
  • In this work the mixed mode I/III fracture of sandstone has been studied experimentally and numerically. The experimental work used three-point bending specimens containing pre-existing cracks, machined at various inclination angles so as to achieve varying proportions of mode I to mode III loading. Dimensionless stress intensity factors were calculated using the extended finite element method (XFEM) for and compared with existing results from literature calculated using conventional finite element method. A total of 28 samples were used to conduct the fracture test with 4 specimens for each of 7 different inclination angles. The fracture load and the geometry of the fracture surface were obtained for different mode mixities. Prediction of the fracture loads and the geometry of the fracture surface were made using XFEM coupled with a cohesive zone model (CZM) and showed a good comparison with the experimental results.

Prediction Model of Inclination to Visit Jeju Tourist Attractions based on CNN Deep Learning

  • YoungSang Kim
    • International Journal of Advanced Culture Technology
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    • v.11 no.3
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    • pp.190-198
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    • 2023
  • Sentiment analysis can be applied to all texts generated from websites, blogs, messengers, etc. The study fulfills an artificial intelligence sentiment analysis estimating visiting evaluation opinions (reviews) and visitor ratings, and suggests a deep learning model which foretells either an affirmative or a negative inclination for new reviews. This study operates review big data about Jeju tourist attractions which are extracted from Google from October 1st, 2021 to November 30th, 2021. The normalization data used in the propensity prediction modeling of this study were divided into training data and test data at a 7.5:2.5 ratio, and the CNN classification neural network was used for learning. The predictive model of the research indicates an accuracy of approximately 84.72%, which shows that it can upgrade performance in the future as evaluating its error rate and learning precision.

Investigation of brassinosteroid substances in the shoots of japonica type Korean rice (일반계 벼의 brassinosteroid활성물질 검색)

  • Hyun, Kyu-Hawn;Park, Keun-Hyung
    • Applied Biological Chemistry
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    • v.33 no.4
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    • pp.307-314
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    • 1990
  • Brassinosteroid-like substances in two japonica type Korean rices were investigated. The extracts from the shoots at the maximum tillering stage were purified by solvent fractionation, silica gel adsorption chromatography, Sephadex LH-20 chromatography, charcoal adsorption chromatography, preparative TLC, Bondesil chromatography and HPLC of normal phase and reverse phase, successively. Biological activity of each purification step were monitored by the rice lamina inclination test. Two cultivars tested in this experiment produced brassinosteroids and endogenous brassinosteroids showing similiarity between two cultivars.

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Heading Failure Modes during Underground Excavation (지하공간 건설에 따른 굴착전면의 파괴모드)

  • Kwon, Oh-Yeob;Cho, Jae-Wan;Shin, Jong-Ho;Choi, Ypng-Ki;Shin, Yong-Suk
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.409-416
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    • 2005
  • Design analysis for underground spaces requires evaluating stability related to tunnel collapses. A failure mode is one of the critical factors in the conventional methods of stability analysis. Therefore identification of failure modes is essential in securing safe construction in the phase of design analysis, instrumentation planning and implementation of reinforcing measures. In this study failure modes at the tunnel heading in granular soils are investigated using physical model tests and numerical simulation for various tunnel depths and ground surface inclinations. Test results indicated that the effect of depth and inclination of ground surface on a failure mode are significant. It is identified that, with an incase in depth, failure modes become localized in a region close to the tunnel. It is also known that an increase in the inclination of ground surface results in inclined and wide failure modes.

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Application and its reinforcing effect of soil nailed-drilled shafts (Soil Nail로 보강된 현장타설말뚝의 적용성 및 보강효과 분석)

  • Jeong, Sang-Seom;Kim, Byung-Chul;Lee, Dae-Soo;Kim, Dae-Hong;Kim, Dae-Hak
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.50-57
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    • 2004
  • In this study reinforcing effect of soil nailed-drilled shafts subjected to axial and lateral loads were evaluated. Special attention was given to the reinforcing effects of soil nails placed from the drilled shafts to surrounding weathered- and soft-rocks based on model tests, numerical analyses and load tests. The model tests and numerical analyses are conducted to analyze the reinforcing effect of various conditions of number, inclination, position and length. The results of 1/40 scale model tests and numerical analyses show that as the number of reinforcing level increases, the incremental effect of reinforcement tends to increase, whereas the reinforcing effect on relative position is negligible. In addition there is a reinforcing effect as the inclination angle increaes up to 30 degrees. Based on the results of tensile load tests, soil nailed-drilled shafts has a considerably smaller settlement to reach the ultimate level when compared with the result of un-reinforced drilled shafts. For compression tests, there is a reinforcing effect of about 200% measured.

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Analysis of the Dynamic Behavior of Guardrail Posts in Sloping Ground using LS-DYNA (LS-DYNA를 이용한 비탈면에 설치된 가드레일 지주의 동적거동)

  • LEE, Dong Woo;Woo, Kwang Sung
    • International Journal of Highway Engineering
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    • v.19 no.1
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    • pp.21-28
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    • 2017
  • PURPOSES : This paper presents a finite element model to accurately represent the soil-post interaction of single guardrail posts in sloping ground. In this study, the maximum lateral resistance of a guardrail post has been investigated under static and dynamic loadings, with respect given to several parameters including post shape, embedment depth, ground inclination, and embedment location of the steel post. METHODS : Because current analytical methods applied to horizontal ground, including Winkler's elastic spring model and the p-y curve method, cannot be directly applied to sloping ground, it is necessary to seek an alternative 3-D finite element model. For this purpose, a 3D FHWA soil model for road-base soils, as constructed using LS-DYNA, has been adopted to estimate the dynamic behavior of single guardrail posts using the pendulum drop test. RESULTS : For a laterally loaded guardrail post near slopes under static and dynamic loadings, the maximum lateral resistance of a guardrail post has been found to be reduced by approximately 12% and 13% relative to the static analysis and pendulum testing, respectively, due to the effects of ground inclination. CONCLUSIONS : It is expected that the proposed soil material model can be applied to guardrail systems installed near slopes.

EXPERIMENTAL EVALUATION OF USED CARS FOR FRONTAL COLLISION COMPATIBILITY

  • Lim, J.H.;Park, I.S.;Heo, S.J.
    • International Journal of Automotive Technology
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    • v.7 no.6
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    • pp.715-720
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    • 2006
  • This research investigates injury values and vehicle deformation for vehicle frontal crash compatibility. To investigate compatibility in an individual case, it is possible to impact two vehicles and evaluate the injury values and deformations in both vehicles. In this study, four tests were conducted to evaluate compatibility. A large and mini vehicle were subjected to a frontal car-to-car crash test at a speed of 48.3 km/h with an offset of 40%. An inclination car-to-car crash test using the large and small vehicle were conducted at 30 km/h at a $30^{\circ}$ angle. The results of the 48.3 km/h, car-to-car frontal crash revealed extremely high injury values on the chest and upper leg of the Hybrid III 50% driver dummy with seatbelt in the mini vehicle compared to the large vehicle. For the 30 km/h, car-to-car inclination crash, however, injury values in the small vehicle were 1.5 times higher compared to the large vehicle.

Factors That Influence the Adoption of the Internet Market (인터넷 상거래시장 진출결정에 영향을 주는 요인에 관한 연구)

  • 박흥국
    • The Journal of Information Systems
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    • v.8 no.2
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    • pp.129-143
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    • 1999
  • A great number of companies are currently examining the opportunities made available through the internet. This research aims to identify the factors that influence the adoption of the internet market. The innovation-IT-diffusion theory provide the theoretical foundation for this study. Seven factors were found to influence the adoption level of the internet market. They are top management support, cost efficiency, inclination toward new technology, absorptive capacity, institutional support, competitors move and customer pressure. Nonparametric test was used to test hypotheses. The results shows that top management support is the most important factor, and institutional support is not related to the adoption of the internet market.

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Strength Estimation of Joints in Floating Concrete Structures Subjected to Shear (전단을 받는 부유식 콘크리트 구조물 접합부의 강도 평가)

  • Yang, In-Hwan;Kim, Kyung-Cheol
    • Journal of Navigation and Port Research
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    • v.37 no.2
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    • pp.155-163
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    • 2013
  • This study explores the structural behavior of module joints in floating concrete structures subjected to shear. Crack patterns, shear behavior and shear capacity of shear keys in joints of concrete module were investigated. Test parameters included shear key shape, or inclination of shear keys, confining stress levels and compressive strength of concrete. Test results showed that shear strength of joints increased as shear key inclination increased. Test results also showed that shear strength of concrete module joints increased with the increase of confining stress levels. The equation for predicting shear strength of joints was suggested, which was based on the test results. Shear strength prediction by using the equation suggested in this study showed good agreement with test results.