• 제목/요약/키워드: System Stability

검색결과 10,122건 처리시간 0.037초

Development of stability evaluation system for retaining walls: Differential evolution algorithm-artificial neural network

  • Dong-Gun Lee;Sang-Yun Lee;Ki-Il Song
    • Geomechanics and Engineering
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    • 제34권3호
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    • pp.329-339
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    • 2023
  • The objective of this study is to develop a Stability Evaluation System for retaining walls to assess their safety in real-time during excavation. A ground investigation is typically conducted before construction to gather information about the soil properties and predict wall stability. However, these properties may not accurately reflect the actual ground being excavated. To address this issue, the study employed a differential evolution algorithm to estimate the soil parameters of the actual ground. The estimated results were then used as input for an artificial neural network to evaluate the stability of the retaining walls. The study achieved an average accuracy of over 90% in predicting differential settlement, wall displacement, anchor force, and structural stability of the retaining walls. If implemented at actual excavation sites, this approach would enable real-time prediction of wall stability and facilitate effective safety management. Overall, the developed Stability Evaluation System offers a promising solution for ensuring the stability of retaining walls during construction. By incorporating real-time soil parameter analysis, it enhances the accuracy of stability predictions and contributes to proactive safety management in excavation projects.

Absolute Stability of the Simple Fuzzy Logic Controller

  • Park, Byung-jae
    • 한국지능시스템학회논문지
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    • 제11권7호
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    • pp.574-578
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    • 2001
  • The stability analysis for the fuzzy logic controller (FLC) has widely been reported. Furthermore many research in the FLC has been introduced to decrease the number of parameters representing the antecedent part of the fuzzy control rule. In this paper we briefly explain a single-input fuzzy logic controller (SFLC) or simple-structured FLC which uses only a single input variable. And then we analyze that it is absolutely stale based on the sector bounded condition. We also show the feasibility of the proposed stability analysis through a numerical example of a mass-damper-spring system.

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A New Approach to the Stability Analysis Method of Net-worked Control Systems

  • Joonhong Jung;Park, Sooyoung;Park, Kiheon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.53.6-53
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    • 2002
  • $\textbullet$ Present a new stability analysis method of NCSs $\textbullet$ Propose the stability condition of NCSs with dynamic controller $\textbullet$ Find the stability region where NCSs for power system are guaranteed to be stable $\textbullet$ Determine a proper sampling period of NCSs that preserves desired stability performance $\textbullet$ Experiment : NCSs for power system using CAN.

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웨이브 변수 기반 원격조작시스템의 안정성 및 성능 해석 (Stability and Performance Analysis of Wave Variable based Teleoperation System)

  • 서일홍;김형욱
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.325-329
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    • 2003
  • In this paper. the stability and performance analysis of wave-based teleoperation system is presented. For stability and performance analysis with respect to the variation of characteristic impedance b, loop gains of communication channel and minimum value of trasmitted impedance from slave side to the master side are considered. The stability of slave side may be enhanced by increasing characteristic impedance b, whereas exssively high value of b may degrade the performance, which imply a tradeoff between stability and performance.

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부하모델을 고려한 전압 안정도 평가지표개발과 시스템 안정도 연구 (A Study on Developing Voltage Stability Index arid System Stability by Incorporating Dynamic Load Modeling)

  • 위원석;함정필;추진부;김정훈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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    • pp.187-189
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    • 1999
  • Accurate load models allow more precise calculations of power system stability, This paper presents new static voltage stability index considering the load models. Also, We apply the load models for the existent voltage stability indices, and evaluate them.

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Analysis of the Static and Dynamic Stability Properties of the Unmaned Airship

  • Lee, Hae Chang
    • International Journal of Aeronautical and Space Sciences
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    • 제2권2호
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    • pp.82-94
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    • 2001
  • The purpose of this paper is to analyze the static and dynamic stability-of the unmanned airship under development ; the target airship's over-all length of hull is 50m and the maximum diameter is 12.5m. For the analysis, the dynamic model of an airship was defined and both the nonlinear and linear dynamic equations of motion were derived. Two different configuration models (KA002Y and KA003Y) of the airship were used for the target model of the static stability analysis and the dynamic stability analysis. From the result of analyses, though the airship is unstable in static stability, dynamic characteristics of the airship can provide the stable dynamic stability. All of the results, airship models and dynamic flight equations will be an important basement and basic information for the next step of developing the automatic flight control system(AFCS) and the stability augmentation system(SAS) for the unmanned airship as well as for the stratospheric airship in the future.

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모터부하를 고려한 ON-LINE 안정도 해석 (Power System Stability Analysis Considering Motor Loads)

  • 박지호;백영식;이희춘
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 A
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    • pp.316-318
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    • 2000
  • In this paper. we have simulated the transient stability of power system with motor loads. In study of power system stability, modelling of motors is required for the system with large concentrations of motors. Therefore the dynamics attributable to motors are usually the most significant aspects of dynamics characteristics of system loads. A synchronous motor is modelled as a dynamic load. We investigate the effect of synchronous motors of Kwang Yang network with three phase fault.

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The Impact of Financial Inclusion on Financial Stability in Asian Countries

  • PHAM, Manh Hung;DOAN, Thi Phuong Linh
    • The Journal of Asian Finance, Economics and Business
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    • 제7권6호
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    • pp.47-59
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    • 2020
  • This paper intends to explore the relationship between financial inclusion and financial stability under the scope of Asian economies. The linkage will be thoroughly investigated with country-level and bank-level data of 42 countries in three separate years: 2011, 2014, and 2017. In this study, an inclusive financial system is assessed by two dimensions: usage of financial services and access to the financial system. Usage of financial services ranges from account to credit, savings and payment services. Access to financial system measures the financial outreach where individuals can use financial services. Meanwhile, financial stability, which proxied by Bank Z-score is regarded as the dependent variable. We apply fixed effects regression and random effects regression to capture the impacts of financial inclusion upon financial stability. To enhance the robustness of the model, the Feasible Generalized Least Squares (FGLS) regression is therefore adopted as the solution for the random effects regression. The empirical findings exhibit an overall weak positive influence of financial inclusion on financial stability. The research results also provide both financial institutions and governments with insightful information, which helps them to have an appropriate financial development strategy, improve the regulatory framework and consequently enhance financial stability for the whole system.

강선의 인장력과 추가 Half pin이 혼성외고정장치 시스템의 안정성에 미치는 영향 (Effects of Pre-tension and Additional Half-pin on Fracture Stability in Hybrid External Fixator System)

  • 김윤혁;이현근;박원만;오종건
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.389-392
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    • 2004
  • It is clinically well known that pre-tension of wires increases the fracture stability in ring or hybrid external fixation. In some cases, additional half pin should be necessary to increase the stability when soft tissue impalement occurs during fixation. In this paper, the fracture stability of a hybrid external fixator system with different pre-tension effects and additional half-pins was analysed using FEM to investigate the effects of these pre-tension and half pin on the system stability quantitatively. 3-D finite element models of five different fixator frames were developed using by beam elements. In axial compression analysis, the fracture stiffness was increased maximally 62% as the pre-tension increased. In torsion analysis, in the other hand, there is little variations in the fracture stiffness. Additional half pin increased the system stiffness about 200 %. From the results, proper pre-tension and additional half pin would provide good methods to increase the fracture stability of the hybrid external fixator and provide more surgical options to minimize soft tissue damage at the fracture site.

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송전계통 과도 안정도 향상을 위한 최적 순차 재폐로에 관한 연구 (A Study on Optimal Sequential Reclosing to Improve Transient Stability in Transmission System)

  • 권기현;오윤식;박지경;조규정;손승현;김철환
    • 전기학회논문지
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    • 제62권10호
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    • pp.1354-1360
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    • 2013
  • In transmission system, reclosing scheme is very useful method to improve continuity of power supply and reliability of system. Especially, high speed reclosing which is used generally in transmission systems has a benefit improving transient stability. However, the reclosing can jeopardize the stability under the condition having high difference of voltage phase angle between both ends. Thus, this paper proposes optimal sequential reclosing scheme to improve transient stability due to reclosing operation. The optimal sequential reclosing is that each phase is closed sequentially considering transient energy. In this paper, 345kV and 154kV transmission system is modeled using EMTP (ElectroMagnetic Transient Program) to verify the performance and effectiveness of optimal sequential reclosing on transient stability. Also, Integral Square Error(ISE) method is used to assess the transient stability.