• 제목/요약/키워드: Nonlinear behavior

검색결과 2,889건 처리시간 0.031초

전문가시스템의 성능평가에 관한 연구 : 렌즈모델분석 (A Study on the Evaluation of an Expert System에s Performance : Lens Model Analysis)

  • 김충영
    • Journal of Information Technology Applications and Management
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    • 제11권1호
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    • pp.117-135
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    • 2004
  • Since human decision making behavior is likely to follow nonlinear strategy, it is conjectured that the human decision making behavior can be modeled better by nonlinear models than by linear models. All that linear models can do is to approximate rather than model the decision behavior. This study attempts to test this conjecture by analyzing human decision making behavior and combining the results of the analysis with predictive performance of both linear models and nonlinear models. In this way, this study can examine the relationship between the predictive performance of models and the existence of valid nonlinear strategy in decision making behavior. This study finds that the existence of nonlinear strategy in decision making behavior is highly correlated with the validity of the decision (or the human experts). The second finding concerns the significant correlations between the model performance and the existence of valid nonlinear strategy which is detected by Lens Model. The third finding is that as stronger the valid nonlinear strategy becomes, the better nonlinear models predict significantly than linear models. The results of this study bring an important concept, validity of nonlinear strategy, to modeling human experts. The inclusion of the concept indicates that the prior analysis of human judgement may lead to the selection of proper modeling algorithm. In addition, lens Model Analysis is proved to be useful in examining the valid nonlinearity in human decision behavior.

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교량의 지진거동에 미치는 영향인자에 관한 연구 (A Study of influence factors on the bridge seismic behavior)

  • 최종만;국승규;김준범;정동원
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2005년도 학술발표회 논문집
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    • pp.372-379
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    • 2005
  • The earthquake resistant design concept allows the nonlinear behavior of structures under the design earthquake. Therefore the response spectrum method provided in most codes introduces the response modification factors to consider the nonlinear behavior in the design process. For bridges, the response modification factors are given according to the ductility as well as the redundancy of piers. In this study, among influence factors on the nonlinear seismic behavior, the randomness of artificial accelerograms simulated with different durations, the pier ductility represented by the inelastic behavior characteristic curve and the regularity represented by pier heights are selected. The influence of such factor on the seismic behavior is investigated by comparing response modification factors calculated with the nonlinear time step analysis.

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Effects of the nonlinear behavior of lead-rubber bearings on the seismic response of bridges

  • Olmos, B.A.;Roesset, J.M.
    • Earthquakes and Structures
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    • 제1권2호
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    • pp.215-230
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    • 2010
  • The main objectives of this work were to investigate the effects of the nonlinear behavior of the isolation pads on the seismic response of bridges with rubber bearings, and to identify when base isolation improved their seismic performance. To achieve these objectives a parametric study was conducted designing a set of bridges for three different soil types and varying the number of spans, span lengths, and pier heights. The seismic responses (accelerations, displacements and pier seismic forces) were evaluated for three different structural models subjected to three earthquakes with different dynamic characteristics. The first represented bridges without base isolation; the second corresponded to the same bridges including now rubber bearings as an isolation system, with linear elastic behavior that shifted the natural period of the bridge by a factor of 2 to 4. In the third model the seismic response of bridges supported on lead-Rubber bearings was studied accounting for the nonlinear behavior of the lead. The results show clearly the importance of the nonlinear behavior on the seismic performance of the bridges.

Effects of a One-Way Clutch on the Nonlinear Dynamic Behavior of Spur Gear Pairs under Periodic Excitation

  • Cheon Gill-Jeong
    • Journal of Mechanical Science and Technology
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    • 제20권7호
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    • pp.941-949
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    • 2006
  • Nonlinear behavior analysis was used to verify whether a one-way clutch is effective for reducing the torsional vibration of a paired spur gear system under periodic excitation. The dynamic responses were studied over a wide frequency range by speed sweeping to check the nonlinear behavior using numerical integration. The gear system with a one-way clutch showed typical nonlinear behavior. The oscillating component of the dynamic transmission error was reduced over the entire frequency range compared to a system without a one-way clutch. The one-way clutch also eliminated unsteady continuous jump phenomena over multiple solution bands, and prevented double-side contact, even with very small backlash. Installing a one-way clutch on both sides of the gear system was more effective at mitigating the negative effects of external periodic excitation and various parameter changes than a conventional gear system without a one-way clutch.

Nonlinear Behavior in Love Model with Discontinuous External Force

  • Bae, Youngchul
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제16권1호
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    • pp.64-71
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    • 2016
  • This paper proposes nonlinear behavior in a love model for Romeo and Juliet with an external force of discontinuous time. We investigated the periodic motion and chaotic behavior in the love model by using time series and phase portraits with respect to some variable and fixed parameters. The computer simulation results confirmed that the proposed love model with an external force of discontinuous time shows periodic motion and chaotic behavior with respect to parameter variation.

비선형 단면해석을 통한 합성지하벽의 휨 거동 분석 및 설계 (Analysis and Design on the Flexural Behavior of Composite Basement Wall Through Nonlinear Sectional Analysis)

  • 서수연;김현우
    • 대한건축학회논문집:구조계
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    • 제36권2호
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    • pp.145-153
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    • 2020
  • The purpose of this study is to investigate the effects of composition of underground structural wall and H-pile in soil cement. The results of previous experimental studies are re-analyzed and the nonlinear cross-sectional analyses of composite basement walls are performed to verify their nonlinear flexural behavior. Based on the study, it is explained how the gap deformation between H-Pile and RC wall should be considered in the design of flexure of composite underground walls. The nonlinear cross-sectional analysis shows that the load-displacement curves of composite basement wall specimens exhibiting flexural behavior exist between the results of the analysis of the complete and non-composite cases. When predicting the behavior of the composite basement wall by nonlinear cross-sectional analysis, the flexural behavior of the composite basement wall could be suitably predicted by considering the reduction of the composite ratio due to tensile stress acting on shear connectors.

트라이볼로지 변수가 원웨이클러치를 가지는 평기어쌍의 비선형 거동에 미치는 영향 (Effects of Tribological Parameters on the Nonlinear Behavior of a Spur Gear Pair with One-Way Clutch)

  • 천길정
    • Tribology and Lubricants
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    • 제24권5호
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    • pp.241-249
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    • 2008
  • This paper describes the tribological effects on the nonlinear behavior of a spur gear pair with one-way clutch according to the direct contact elastic deformation model over a wide range of speeds, considering the hydrodynamic effects. The effects of various lubrication parameters, such as viscosity, film width, and friction, on the nonlinear dynamic behavior were analyzed. Forces due to the entraining velocity and the hydrodynamic friction were about two orders smaller than normal forces over the whole speed range. While the viscosity has a strong effect on the behavior of gear pair systems, friction has very little effect on torsional behavior. The inclusion of the hydrodynamic effect facilitates nonlinearity by increasing the overlap and damping, as well as decreasing elastic deformation and tooth reaction forces.

냉간성형강재를 이용한 합성보의 구조적인 거동 (The Structural Behavior of Cold-Formed Steel Composite Beams)

  • 양구록;송준엽;권영봉
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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    • pp.206-213
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    • 1999
  • The behavior of composite beams, which are composed of cold-formed steel sheeting and normal strength concrete, have been studied. An analytical method has been developed to trace the nonlinear behavior of composite beams. The nonlinear material properties of steel sheeting, reinforcing steel bar and concrete have been included in the analysis. The nonlinear moment-curvature relation of the composite beam has been described using a cross section analysis method and a simple power model, separately. The load-deflection behavior of the beams has been simulated by step-by-step numerical integration method and is compared with test results.

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Evaluating the accuracy of a new nonlinear reinforced concrete beam-column element comprising joint flexibility

  • Izadpanah, Mehdi;Habibi, AliReza
    • Earthquakes and Structures
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    • 제14권6호
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    • pp.525-535
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    • 2018
  • This study presents a new beam-column model comprising material nonlinearity and joint flexibility to predict the nonlinear response of reinforced concrete structures. The nonlinear behavior of connections has an outstanding role on the nonlinear response of reinforced concrete structures. In presented research, the joint flexibility is considered applying a rotational spring at each end of the member. To derive the moment-rotation behavior of beam-column connections, the relative rotations produced by the relative slip of flexural reinforcement in the joint and the flexural cracking of the beam end are taken into consideration. Furthermore, the considered spread plasticity model, unlike the previous models that have been developed based on the linear moment distribution subjected to lateral loads includes both lateral and gravity load effects, simultaneously. To confirm the accuracy of the proposed methodology, a simply-supported test beam and three reinforced concrete frames are considered. Pushover and nonlinear dynamic analysis of three numerical examples are performed. In these examples the nonlinear behavior of connections and the material nonlinearity using the proposed methodology and also linear flexibility model with different number of elements for each member and fiber based distributed plasticity model with different number of integration points are simulated. Comparing the results of the proposed methodology with those of the aforementioned models describes that suggested model that only uses one element for each member can appropriately estimate the nonlinear behavior of reinforced concrete structures.

복합재 적층셸의 비선형 수치해석 및 실험 (Nonlinear Numerical Analysis and Experiment of Composite Laminated Shell)

  • 조원만;이영신;윤성기
    • 대한기계학회논문집
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    • 제17권8호
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    • pp.2051-2060
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    • 1993
  • A finite element program using degenerated shell element was developed to solve the geometric, material and combined nonlinear behaviors of composite laminated shell. The total Lagrangian method was implemented for geometric nonlinear analysis. The material nonlinear behavior was analyzed by considering the matrix degradation due to the progressive failure in the matrix and matrix-fiber interface after initial failure. The result of the geometric nonlinear analysis showed good agreement with the other exact and numerical solutions. The results of the combined analyses considered both geometric and material nonlinear analyses were compared with the experiments in which internal pressure was applied to the filament wound antisymmetric tubes.