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SEISMIC STABILITY OF SATURATED REINFORCED SOIL WALLS

  • Kuwano, Jiro;Izawa, Jun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09c
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    • pp.66-71
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    • 2010
  • This paper studies the effect of saturation of backfill on the seismic stability of reinforced soil walls (RSWs) using centrifuge shaking table tests. For comparison, degradation of static stability and seismic stability of a RSW under unsaturated condition was also investigated. Test results showed that the RSW under saturated condition had enough static stability. However, seismic stability of saturated RSW significantly decreased as compared with that under unsaturated condition. The saturated model RSW did not collapse, though it showed large deformation. It maintained sufficient stability after shakings although a clear slip surface appeared in the backfill. Finally, it is discussed how to evaluate residual stability of RSWs damaged by earthquakes with test results and the simple evaluation method proposed by authors.

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Stability criterion and its calculation for sail-assisted ship

  • Hu, Yihuai;Tang, Juanjuan;Xue, Shuye;Liu, Shewen
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.7 no.1
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    • pp.1-9
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    • 2015
  • Stability criterion and its calculation are the crucial issue in the application of sail-assisted ship. However, there is at present no specific criterion and computational methods for the stability of sail-assisted ship. Based on the stability requirements for seagoing ships, the stability criterion of the sail-assisted ships is suggested in this paper. Furthermore, how to calculate the parameters and determine some specific coefficients for the ship stability calculation, as well as how to redraw stability curve are also discussed in this paper. Finally, to give an illustration, the proposed method is applied on a sail assisted-ship model with comments and recommendations for improvement.

A comparative study on slope stability by program and stability cahrt (프로그램과 도표에 의한 사면안정해석의 비교연구)

  • Ju, Gyeong-Hun;Kim, Ju-Cheol;Lee, Jong-Gyu
    • Proceedings of the Korean Geotechical Society Conference
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    • 1994.09a
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    • pp.253-258
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    • 1994
  • Recently, computer technique for the analysis of slope stability enable to reduce a considerable time and efforts. And also, stability problems can be approached by using stablility chart which was basically developed to handle the problems under simple conditions only. Most of the conventional slope stability computer programs and stability chart are still based on the general limit equilibrium method. 16 types of sample slopes and 2 types of failure slope were compared and analysed by stability charts and programs. This research work intend to apply 4 types of conventional computer programs based on the same theoretical backgroung and 7 types of stability charts for solving the same stability problems and the results and compared and analysed in order to justify their reliability.

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Relaxed Stability Condition for Affine Fuzzy System Using Fuzzy Lyapunov Function (퍼지 리아푸노프 함수를 이용한 어파인 퍼지 시스템의 완화된 안정도 조건)

  • Kim, Dae-Young;Park, Jin-Bae;Joo, Young-Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.10
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    • pp.1508-1512
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    • 2012
  • This paper presents a relaxed stability condition for continuous-time affine fuzzy system using fuzzy Lyapunov function. In the previous studies, stability conditions for the affine fuzzy system based on quadratic Lyapunov function have a conservativeness. The stability condition is considered by using the fuzzy Lyapunov function, which has membership functions in the traditional Lyapunov function. Based on Lyapunov-stability theory, the stability condition for affine fuzzy system is derived and represented to linear matrix inequalities(LMIs). And slack matrix is added to stability condition for the relaxed stability condition. Finally, simulation example is given to illustrate the merits of the proposed method.

Vehicle Stability Analysis using a Non-linear Simplified Model (비선형 단순 모델을 이용한 차량 안정성 해석)

  • Ko, Young-Eun;Song, Chul-Ki
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.4
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    • pp.29-37
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    • 2008
  • Vehicle stability is a very important subject in vehicle design and control, because vehicle safety is closely dependent upon its dynamic stability. For the vehicle stability analysis, the nonlinear vehicle model of a mid-size car with three DOF - longitudinal, lateral and yaw - is employed. A rigorous method is used to determine the vehicle stability region in plane motion. An algorithm is used to materialize a topology theorem, which enables to find the exact stability region. A stability criterion for the critical cornering is proposed.

Investigation on wind stability of three-tower cable-stayed-suspension hybrid bridges under skew wind

  • Xin-Jun Zhang;Li Bowen;Nan Zhou
    • Wind and Structures
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    • v.38 no.6
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    • pp.427-443
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    • 2024
  • By using a computational program of three-dimensional aerostatic and aerodynamic stability analysis of long-span bridges under skew wind, the dynamic characteristics and structural stability(including the aerostatic and aerodynamic stability) of a three-tower cable-stayed-suspension hybrid bridge with main span of 1 400 meters are investigated numerically under skew wind, and the skew wind and aerostatic effects on the aerostatic and aerodynamic stability of three-tower cable-stayedsuspension hybrid bridge are ascertained. The results show that the three-tower cable-stayed-suspension hybrid bridge is a longspan structure with greater flexibility, and it is more susceptible to the wind action. The aerostatic instability of three-tower cable-stayed-suspension hybrid bridges is characterized by the coupling of vertical bending and torsion of the girder, and the skew wind does not affect the aerostatic instability mode. The skew wind has positive or negative effects on the aerostatic stability of the bridge, the influence is between -5.38% and 4.64%, and in most cases, it reduces the aerostatic stability of the bridge. With the increase of wind yaw angle, the critical wind speed of aerostatic instability does not vary as the cosine rule as proposed by the skew wind decomposition method, the skew wind decomposition method may overestimate the aerostatic stability, and the maximum overestimation is 16.7%. The flutter critical wind speed fluctuates with the increase of wind yaw angle, and it may reach to the minimum value under the skew wind. The skew wind has limited effect on the aerodynamic stability of three-tower cable-stayed-suspension hybrid bridge, however the aerostatic effect significantly reduces the aerodynamic stability of the bridge under skew wind, the reduction is between 3.66% and 21.86%, with an overall average drop of 11.59%. The combined effect of skew and static winds further reduces the critical flutter wind speed, the decrease is between 7.91% and 19.37%, with an overall average decrease of 11.85%. Therefore, the effects of skew and static winds must be comprehensively considered in the aerostatic and aerodynamic stability analysis of three-tower cable-stayed-suspension hybrid bridges.

Jeju area's Voltage Stability Analysis which use the Real Time Voltage Stability Analysis Program (실시간 전압안정도 프로그램을 이용한 제주지역 전압안정도)

  • Lee, Sung-Woo;Ahn, Kyo-Sang;Seo, Dong-Wan;Jang, Moon-Jong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.10
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    • pp.1387-1392
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    • 2012
  • These days people use a lot of electric power, because industry advancement and a standard of living is elevated. So voltage stability analysis and control problems are very important in these days. U.S.A has already developed voltage stability analysis program, and use it on power transmission scheme such as generator overhaul, transmission line off and so on. So voltage stability analysis is more and more interested in Korea, too. In this paper, we introduce a standard theory of voltage stability analysis and real time voltage stability analysis program that use sPMU(Satellite Phasor Measurement Unit). And we also introduce the calculation result about voltage stability in Jeju power transmission system.

THE STABILITY OF THE GENERALIZED FORM FOR THE GAMMA FUNCTIONAL EQUATION

  • Kim, Gwang-Hui;Lee, Young-Whan
    • Communications of the Korean Mathematical Society
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    • v.15 no.1
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    • pp.45-50
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    • 2000
  • The modified Hyers-Ulam-Rassias Stability Of the generalized form g(x+p) : $\phi$(x)g(x) for the Gamma functional equation shall be proved. As a consequence we obtain the stability theorems for the gamma functional equation.

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The Effect of Bank Liquidity on Bank's Stability in the Presence of Managerial Optimism

  • HABIB, Ashfaq;KHAN, Muhammad Asif;MEYER, Natanya
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.8
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    • pp.183-196
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    • 2022
  • Bank stability serves as a prerequisite for the smooth functioning of economic and financial activities in the country. Banks face numerous risks, and liquidity plays an essential role in determining a bank's long-term growth and financial stability. By using the sample of 70 banks of the Gulf Cooperation Council, this study examines the association between funding the liquidity and the creation of liquidity and their impact on bank stability. Firstly, the reciprocal relationship reveals between funding the liquidity and the creation of liquidity by employing the 2SLS regression model. Further, by employing the dynamic GMM model, the research finds that funding liquidity is significant and positively influences bank stability. However, bank stability is significantly negatively influenced by the creation of liquidity, but the combined effect of funding the liquidity and creation of liquidity positively explains the bank stability. Additionally, this study reveals that managerial optimism biases contribute to determining the bank's liquidity and long-term stability. The finding of this study supports the executives, policymakers, and management of banks in understating liquidity risks, efficiency, and bank stability. The findings support regulatory guidelines mainly by the Basel III framework, which places more importance on the joint management of funding the liquidity and creation of liquidity in the economy.