• Title/Summary/Keyword: stability evaluation

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A Study on the Stability Assessment and Application of Rock Slope (암반사면의 안정성 평가 및 적용에 관한 연구)

  • 안종필;박주원;오수동
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.177-184
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    • 1999
  • In general tile evaluation process of rock slope stability is an ambiguous system which is made up of ideas subjected to practical experience of an expert. This paper aims to propose more effective methods that helps engineers to evaluate the stability of rock slope by using RMR(Rock Mass Rating for the Geomechanics Classification) and Stereo-graphic Projection and Fuzzy Approximate Reasoning Concept. the result of this paper is that a rational evaluation of rock slope stability and countermeasures can be achieved thorough RMR. and Stereo-graphic Projection and Fuzzy Approximate Reasoning Concept.

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A Study of stability in ratings for clothing and their woven fabrics (의복과 그 직물에 대한 평가의 재현성 차이에 관한 연구)

  • 유경숙
    • Journal of the Korean Society of Clothing and Textiles
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    • v.25 no.3
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    • pp.560-568
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    • 2001
  • The aim of the present study was to measure intra-individual consistency in clothing and fabric evaluation and to examine its relation to the ratings. A sample of 93 female and 97 male university students rated clothing of 4 styles of daytime wear and 2 fabrics on 15 pairs of polar adjectives twice in 7-days interval. Correlation coefficients between the two ratings for each subject, intra-individual consistency in the evaluation, ranged from -0.12 to 0.89 and mean coefficient was 0.63 of female and -0.01 to 0.78 and mean coefficient was 0.54 of male. Based on the coefficients, the subjects were classified into three groups: high, medium, and low intra-individual consistency. Analysis of variance of mean ratings by the three groups revealed that significant difference existed in 24% of female and 23% of male in 90 combinations of 6 clothing and 15 semantic differential scales. Female of subjects with high intra-individual consistency were most likely definite to evaluate clothing, whereas the ones with low were least. But male subjects were not definite. Mean correlation coefficients for style evaluation subscales of female was 0.39, but male was 0.44. Among the semantic differential scales, high stability in the two ratings was observed for the synthetic clothing evaluation. Correlation coefficients for each clothing obtained from the mean score of the subjects in each semantics differential scale were around 0.98, including that the mean scores of the subjects in each scale could yield excellent stability in clothing evaluation.

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Stability Evaluation Methods of Agricultural Reservoir by Field Monitoring (현장계측에 의한 농업용저수지 제체의 안정관리기법)

  • Lee, Dal-Won;Oh, Beom-Hwan
    • Korean Journal of Agricultural Science
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    • v.30 no.2
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    • pp.164-174
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    • 2003
  • This study was performed to suggest a rational method for the stability evaluation of agricultural reservoir in the very soft ground. The stability methods for agricultural reservoir was used to compare and analyze with various condition by limit equilibrium method. The behavior of settlement-displacement obtained by field monitoring system was used to compare and analyze with various stability methods, and to investigate the applicability of the methods for stability evaluation of agricultural reservoir. The horizontal displacement was abruptly increased when physical properties of soft clay reached its maximum values and therefore, the values of these properties could be used to the fundamental data for stability evaluation. The evaluation of the stability of agricultural reservoir was suggested to use the inclination of curve rather than critical line.

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Assessment of slope stability using multiple regression analysis

  • Marrapu, Balendra M.;Jakka, Ravi S.
    • Geomechanics and Engineering
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    • v.13 no.2
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    • pp.237-254
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    • 2017
  • Estimation of slope stability is a very important task in geotechnical engineering. However, its estimation using conventional and soft computing methods has several drawbacks. Use of conventional limit equilibrium methods for the evaluation of slope stability is very tedious and time consuming, while the use of soft computing approaches like Artificial Neural Networks and Fuzzy Logic are black box approaches. Multiple Regression (MR) analysis provides an alternative to conventional and soft computing methods, for the evaluation of slope stability. MR models provide a simplified equation, which can be used to calculate critical factor of safety of slopes without adopting any iterative procedure, thereby reducing the time and complexity involved in the evaluation of slope stability. In the present study, a multiple regression model has been developed and tested its accuracy in the estimation of slope stability using real field data. Here, two separate multiple regression models have been developed for dry and wet slopes. Further, the accuracy of these developed models have been compared and validated with respect to conventional limit equilibrium methods in terms of Mean Square Error (MSE) & Coefficient of determination ($R^2$). As the developed MR models here are not based on any region specific data and covers wide range of parametric variations, they can be directly applied to any real slopes.

Temporal Stability of Wearer′s Impression Effect - The Accent of Garment Category, Fashion-Level and Wearer′s Body Type - (착용자 인상효과의 시간적 안정성 -의복범주, 유행성, 착용자의 체형 변인을 중심으로 -)

  • 김재숙;김희숙
    • The Research Journal of the Costume Culture
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    • v.10 no.1
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    • pp.28-36
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    • 2002
  • The purposes of the study were to investigate the effect of garment category, fashion-level and wearer's body type on the basis of temporal stability and to extend the contextual framework. The result was as follows 1) On the basis of temporal stability, Korean style, classic style, and large body type have more temporal stability than western style, fashionable style, normal body type. 2) On the basis of temporal stability of impression dimension, impression of appearance knave most temporal stability, next good-bad, next evaluation, next potency, and sociability. 3) In an interaction effect between measuring time and impression of evaluation, western, fashionable, classic style have the greatest interaction effect. In an interaction effect between measuring time and impression of appearance, western style, normal body type have the greatest interaction effect. In an interaction effect between measuring time and impression of good-bad, western, fashionable style have the greatest interaction effect. It is concluded that the results support the context framework on impression formation.

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Stability Evaluation of National Reference Standards for Blood Products in Korea

  • Park, Tae Jun;Choi, Chan Woong;Oh, Ho Kyung;Kim, Jae Ok;Kim, Byung Kuk;Kang, Hyun Kyung;Kwon, Eun Jeong;Gweon, Eun Jeong;Park, Sang Jin;Kang, Ho Il;Jung, Ki Kyung;Park, Sang Mi;Kim, Ji Hye;Han, Ki Won;Jeong, Ja Young
    • Toxicological Research
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    • v.33 no.3
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    • pp.225-231
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    • 2017
  • National reference standards (NRSs) for biologics are established through potency estimation by a multi-center joint study of standard materials used in the approval process for national lot release and quality control of vaccines, blood products, and other biologics. In this study, a stability evaluation was conducted to determine whether the potency of NRSs for six blood products was being maintained at a consistent level in Korea. The present study conducted real-time stability tests via in-vivo/in-vitro bioassay on NRSs for blood coagulation factor VIII concentrate (2nd standard), antithrombin concentrate, prekallikrein activator, anti-hepatitis B immunoglobulin, blood coagulation factor IX concentrate, and anti-tetanus human immunoglobulin, as well as a trend analysis using cumulative annual results. The real-time stability test results showed that the mean potency of six NRSs was all within the control limit. In the trend analysis, the potency of NRS for blood coagulation factor VIII concentrate (2nd standard) showed a decreasing trend, while the potency of all other products had been stably maintained. The present study confirmed that the mean potency of NRSs for six blood products had been stably maintained in Korea. The findings of the present study establish a foundation that can ensure the quality of NRSs for biologics in Korea, and it is expected to make a major contribution to the supply of high-quality biologics.

Regional Evaluation of Slope Stability by Using GIS and Geostatistics Around the Southern Area of Chungju Lake (GIS와 지구통계학을 이용한 충주호 남부지역의 광역적인 사면안정평가)

  • 문상기
    • Economic and Environmental Geology
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    • v.33 no.2
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    • pp.117-128
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    • 2000
  • Regional evaluations of slope stability by the failure criterion and by environmental geological factors were conducted. The failure criterion is the general conditions for plane failure which consider the geometrical conditions between geological discontinuities and topographical slope planes. The factor focused in this condiction is dip and dip direction. Geostatics, named semivariogram was used for establishing structural domains in slope stability evaluation by the failure criterion. The influential range was calculated to 6 km in the case of dip direction of dominant joint set and 7 km in the case of dip of the same dominant joint set. Then applying this failure criterion to the study area produced a slope stability map using the established domains and slopes generated by TIN module of ARC/INFO GIS. This study considered another regional slope stability analysis. 5 failure-driven factors 9the unstable slope map, geology, engineering soil, groundwater, and lineament density) were selected and used as data coverages for regional slope stability evaluation by geoenvironmental factors. These factors were weighted and overlayed in GIS. From the graph of cumulatave area (%) and instability index, finding critical points classified the instability indices. The most unstable slopes are located in the southern area of Mt. Eorae, Dabul-ri, and the eastern area of Junkok-ri in the first area is plane failure. Also, the expected orientations of failure are 59/338 and 86/090 (dip/dip direction).

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Atmospheric Stability Evaluation at Different Time Intervals for Determination of Aerial Spray Application Timing

  • Huang, Yanbo;Thomson, Steven J.
    • Journal of Biosystems Engineering
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    • v.41 no.4
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    • pp.337-341
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    • 2016
  • Purpose: Evaluation of atmospheric conditions for proper timing of spray application is important to prevent off-target movement of crop protection materials. Susceptible crops can be damaged downwind if proper application procedure is not followed. In our previous study, hourly data indicated unfavorable conditions, primarily between evening 18:00 hrs in the evening and 6:00 hrs next morning, during clear conditions in the hot summer months in the Mississippi delta. With the requirement of timely farm operations, sub-hourly data are required to provide better guidelines for pilots, as conditions of atmospheric stability can change rapidly. Although hourly data can be interpolated to some degree, finer resolution for data acquisition of the order of 15 min would provide pilots with more accurate recommendations to match the data recording frequency of local weather stations. Methods: In the present study, temperature and wind speed data obtained at a meteorological tower were re-sampled to calculate the atmospheric stability ratio for sub-hour and hourly recommendations. High-precision evaluation of temperature inversion periods influencing atmospheric stability was made considering strength, time of occurrence, and duration of temperature inversion. Results and Discussion: The results indicated that atmospheric stability could be determined at different time intervals providing consistent recommendations to aerial applicators, thereby avoiding temperature inversion with minimal off-target drift of the sprayed liquid.

Analysis of pile group behaviour to adjacent tunnelling considering ground reinforcement conditions with assessment of stability of superstructures

  • Young-Jin Jeon;Cheol-Ju Lee
    • Geomechanics and Engineering
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    • v.33 no.5
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    • pp.463-475
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    • 2023
  • Tunnel construction activity, conducted mainly in mountains and within urban centres, causes soil settlement, thus requiring the relevant management of slopes and structures as well as evaluations of risk and stability. Accordingly, in this study we performed a three-dimensional finite element analysis to examine the behaviour of piles and pile cap stability when a tunnel passes near the bottom of the foundation of a pile group connected by a pile cap. We examined the results via numerical analysis considering different conditions for reinforcement of the ground between the tunnel and the pile foundation. The numerical analysis assessed the angular distortion of the pile cap, pile settlement, axial force, shear stress, relative displacement, and volume loss due to tunnel excavation, and pile cap stability was evaluated based on Son and Cording's evaluation criterion for damage to adjacent structures. The pile located closest to the tunnel under the condition of no ground reinforcement exhibited pile head settlement approximately 70% greater than that of the pile located farthest from the tunnel under the condition of greatest ground reinforcement. Additionally, pile head settlement was greatest when the largest volume loss occurred, being approximately 18% greater than pile head settlement under the condition having the smallest volume loss. This paper closely examines the main factors influencing the behaviour of a pile group connected by a pile cap for three ground reinforcement conditions and presents an evaluation of pile cap stability.

A Proposal of the Evaluation Method for Rock Slope Stability Using Logistic Regression Analysis (로지스틱 회귀분석을 통한 암반사면의 안정성 평가법 제안)

  • 이용희;김종열
    • Tunnel and Underground Space
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    • v.14 no.2
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    • pp.133-141
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    • 2004
  • Through the many site investigations, different methods for evaluating stability of rock slopes have been proposed. Those methods, however, may lead to different results depending on the subjective judgments associated with the selection of the evaluation items and the application of weighting factor. Accordingly, binary logistic regression analysis was carried out to ensure fair appliction of the weighting factor, leading to an equation for evaluating the stability of rock slopes.