• 제목/요약/키워드: dynamic of reason

검색결과 412건 처리시간 0.031초

철도 무도상판형교의 고유진동특성에 대한 연구 (A Study on the Characteristic of Natural Frequencies of Railway Open Deck Plate Girder Bridges)

  • 오지택;최진유;김현민
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 추계학술대회 논문집(II)
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    • pp.1041-1046
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    • 2002
  • A railway open deck plate girder bridge without ballast should support relatively heavier vehicle loads compared with its self-weight. For such a reason, actual dynamic response of the bridge is considerably differing with normal prediction because additional masses added from vehicle to a bridge have an effect on the dynamic characteristics of the bridge. These differences affect to the estimation of a natural frequency change that adopted for one of the evaluation technique of strength decrease, and these make trouble to the analysis of a natural frequency from the field test data that measured at the bridge subjected to a running vehicle. In this study, classification of mass participation ratio for each component of open deck plate girder bridge without ballast and the comparison according to the change of vibration characteristics for the case of subjected to a running vehicle were accomplished.

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Assessment of Post-Earthquake Fire Behavior of a Steel MRF Building in a Low Seismic Region

  • Chicchi, Rachel;Varma, Amit
    • 국제강구조저널
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    • 제18권4호
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    • pp.1470-1481
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    • 2018
  • Building-level response to post-earthquake fire hazards in steel buildings has been assessed using primarily two-dimensional analyses of the lateral force resisting system. This approach may not adequately consider potential vulnerabilities in the gravity framing system. For this reason, three-dimensional (3D) finite element models of a 10-story case study building with perimeter moment resisting frames were developed to analyze post-earthquake fire events and better understand building response. Earthquakes are simulated using ground motion time histories, while Eurocode parametric time-temperature curves are used to represent compartment fires. Incremental dynamic analysis and incremental fire analysis procedures capture a range of hazard intensities. Findings show that the structural response due to earthquake and fire hazards are somewhat decoupled from one another. Regardless of the level of plastic hinging present in the moment framing system due to a seismic event, gravity column failure is the initiating failure mode in a fire event.

Study on the space frame structures incorporated with magnetorheological dampers

  • Xu, Fei-Hong;Xu, Zhao-Dong;Zhang, Xiang-Cheng
    • Smart Structures and Systems
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    • 제19권3호
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    • pp.279-288
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    • 2017
  • Magnetorheological damper has received significant attention in recent years due to the reason that it can offer adaptability of active control devices without requiring the associated large power sources. In this paper, performance tests on a MR damper are carried out under different currents, excitation amplitudes and frequencies, the damping characteristics and energy dissipation capacity of the MR damper are analyzed. Elasto-plastic dynamic analysis on a space frame structure incorporated with MR dampers is conducted, and numerical analysis results show that MR dampers can significantly mitigate the structural vibration responses. Finally, the genetic algorithm with the improved binary crossover and mutation technique is adopted to optimize the arrangement of MR dampers. Numerical results show that dynamic responses of the optimal controlled structure are mitigated more effectively.

N값과 전단파 속도의 상관식 비교 (Comparison of Correlation Equations between N value and Shear Wave Velocity)

  • 공진영;채휘영;천병식
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 춘계 학술발표회
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    • pp.656-665
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    • 2010
  • Shear modulus has been recognized as one of the important soil properties in dynamic analysis of ground and can be calculated from in situ measurement of shear wave velocity. Field seismic tests are the most accurate but expensive methods to investigate dynamic ground characteristics. Due to that reason, empirical equations for estimating the shear wave velocity are widely used rather than conducting in-situ tests. The most common equations are based on the N value obtained in conjuctions with a standard penetration test. In this paper, the field datas of standard penetration test and suspension PS logging measured in 126 sites of Korea were summarized and the correlation equations between N value and shear wave velocity are suggested.

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다축 제어 시뮬레이터의 동특성 해석에 관한 연구 (A Study on the Dynamic Characteristic Analysis of Multi-axis Simulator)

  • 정상화;박용래;류신호;김현욱;나윤철
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.715-718
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    • 2001
  • Test in the development of vehicle consist of driving test and simulation test. The last one has many advantages. It can reduce time and cost during development, can overcome the spacial and environmental limitation, and can provides repeatabilities of similar experiments and various data. In these reason, the simulation test is used more for analysis and development of new vehicle. In this research the result of kinematic analysis on multi-axis simulator is compared with the simulated result using dynamic analysis program, ADAMS, and the maximum stress and strain are analyzed for the safety of link and specifications of optimal design using finite element method.

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3축 로드 시뮬레이터의 링크부의 동특성 및 FEM 해석에 관한 연구 (A Study on the Dynamic Characteristics and Finite element analysis of 3-axis road simulator link unit)

  • 박용래;정상화;류신호
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 추계학술대회 논문집
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    • pp.694-697
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    • 1997
  • As the life cycle of the vehicle become shorter, the method that reduce the development time of new model become more important. In this reason, the development of the simulator that provides similar environment with the actual vehicle load characteristics is increasing. In this paper, the link unit of the 3-axis road simulator is designed and simulated with dynamic analysis software ADMS. and the maximum stress and strain are analyzed for the safety of link and specifications of optimal design using finite element method.

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A Reusable SQL Injection Detection Method for Java Web Applications

  • He, Chengwan;He, Yue
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권6호
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    • pp.2576-2590
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    • 2020
  • The fundamental reason why most SQL injection detection methods are difficult to use in practice is the low reusability of the implementation code. This paper presents a reusable SQL injection detection method for Java Web applications based on AOP (Aspect-Oriented Programming) and dynamic taint analysis, which encapsulates the dynamic taint analysis processes into different aspects and establishes aspect library to realize the large-grained reuse of the code for detecting SQL injection attacks. A metamodel of aspect library is proposed, and a management tool for the aspect library is implemented. Experiments show that this method can effectively detect 7 known types of SQL injection attack such as tautologies, logically incorrect queries, union query, piggy-backed queries, stored procedures, inference query, alternate encodings and so on, and support the large-grained reuse of the code for detecting SQL injection attacks.

Three-Dimensional Flow Simulations of End-to-Side Vascular Anastomoses : Flow Dynamic Aspect on Preferential Development of Intimal Hyperplasia or Thrombosis

  • Kim, Young H.;Krishnan B.Chandran
    • 대한의용생체공학회:의공학회지
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    • 제15권3호
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    • pp.253-258
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    • 1994
  • Three-dimensional steady and pulsatile flows in an end-to-side anastomosis were investigated using a finite difference method in order to understand the flow dynamics in the preferential development of distal anastomotic intimal hyperplasia or thrombosis. Steady flow results revealed that a double helical vortex was formed in the host artery and flow recirculations near toe find heel regions were restricted due to the secondary flow. Oscillating wall shear stress with significant secondary flow might be flow dynamic reason of developing intimal hyperplasia or thrombosis near the anastomotic region.

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유기박막의 광 자격에 관한 연구 (A Study on the Light Stimulus of Organic Thin Films)

  • 김성진;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.283-286
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    • 2000
  • In this paper, generation form of displacement current was compared and measured induce monolayers which 8A5H with Pure azobenzene. Light response of two monolayers which compared and measured though they are the same isomer. The experimental results are as following; In case of ultraviolet($\lambda_1$) and visible($\lambda_2$) irradiation on 8A5H induce monolayers depositioned on board the peak of current was detected about 10[fA]. but light irradiation on pure azobenzene any particular reaction for detailed. This is the reason of hydrophobicity construct in molecule structures its molecule dynamic behaviour in cis and trans was not due to activated.

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Emotion - Based Intelligent Model

  • Ko, Sung-Bum;Lim, Gi-Young
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.178.5-178
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    • 2001
  • We, Human beings, use both powers of reason and emotion simultaneously, which surely help us to obtain flexible adaptability against the dynamic environment. We assert that this principle can be applied into the general system. That is, it would be possible to improve the adaptability by covering a digital oriented information processing system with an analog oriented emotion layer. In this paper, we proposed a vertical slicing model with an emotion layer in It. And we showed that the emotion-based control allows us to improve the adaptability of a system at least under some conditions.

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