• Title/Summary/Keyword: Dynamic effects

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Clamping effects on the dynamic characteristics of composite tool bars (고정부 조건이 복합재료 공구용 바의 동적 특성에 미치는 영향)

  • 황희윤;김병철;이대길
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2003.10a
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    • pp.199-202
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    • 2003
  • The dynamic characteristics of composite tool bars depend on the clamping conditions such as clamping force, stiffness and surface characteristics of clamping parts as well as the basic structures. Therefore, in this work, the effects of clamping part conditions on the dynamic characteristics of cantilever type composite machine tool structures with clamped joint were investigated because the cantilever type machine tool structures are ideal cases for composite application to increase the natural frequency and damping of structures. New design of the clamping part was developed in order to improve shear properties of the clamping part and dynamic characteristics of composite tool bars. From FE analysis and Impulse response tests, dynamic characteristics were obtained with respect to the clamping part conditions of the new design.

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Dynamic buckling response of temperature-dependent functionally graded-carbon nanotubes-reinforced sandwich microplates considering structural damping

  • Shokravi, Maryam;Jalili, Nader
    • Smart Structures and Systems
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    • v.20 no.5
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    • pp.583-593
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    • 2017
  • This research deals with the nonlocal temperature-dependent dynamic buckling analysis of embedded sandwich micro plates reinforced by functionally graded carbon nanotubes (FG-CNTs). The material properties of structure are assumed viscoelastic based on Kelvin-Voigt model. The effective material properties of structure are considered based on mixture rule. The elastic medium is simulated by orthotropic visco-Pasternak medium. The motion equations are derived applying Sinusoidal shear deformation theory (SSDT) in which the size effects are considered using Eringen's nonlocal theory. The differential quadrature (DQ) method in conjunction with the Bolotin's methods is applied for calculating resonance frequency and dynamic instability region (DIR) of structure. The effects of different parameters such as volume percent of CNTs, distribution type of CNTs, temperature, nonlocal parameter and structural damping on the dynamic instability of visco-system are shown. The results are compared with other published works in the literature. Results indicate that the CNTs have an important role in dynamic stability of structure and FGX distribution type is the better choice.

SSI Effects on the Dynamic Response of Structures (구조물-지반 상호작용이 구조물의 동적거동에 미치는 영향)

  • 김용석
    • Computational Structural Engineering
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    • v.6 no.2
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    • pp.87-93
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    • 1993
  • Recently it is recognized that the effects of structure-soil interaction(SSI) on the response of structures are important in the dynamic analysis of structures. In this study, theoretical and experimental investigations were performed to study the SSI effects(mainly inertial interaction) on the dynamic response of buildings utilizing the finite element foumulation. Theoretical studies were performed with two idealized buildings(stubby one and slender one) built on the homogeneous soil layer and having the small embedment ratio. Experimental investigations were also carried out for two buildings built on the pile foundation in Mexico City, experienced the 1985 Earthquake. The results of this study show that the SSI effects are significant on the response of structures due to the change of fundamental frequency and effective damping ratio, and that it is necessary to include the SSI effects on the dynamic analysis of structures.

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Effects of the facial expression presenting types and facial areas on the emotional recognition (얼굴 표정의 제시 유형과 제시 영역에 따른 정서 인식 효과)

  • Lee, Jung-Hun;Park, Soo-Jin;Han, Kwang-Hee;Ghim, Hei-Rhee;Cho, Kyung-Ja
    • Science of Emotion and Sensibility
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    • v.10 no.1
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    • pp.113-125
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    • 2007
  • The aim of the experimental studies described in this paper is to investigate the effects of the face/eye/mouth areas using dynamic facial expressions and static facial expressions on emotional recognition. Using seven-seconds-displays, experiment 1 for basic emotions and experiment 2 for complex emotions are executed. The results of two experiments supported that the effects of dynamic facial expressions are higher than static one on emotional recognition and indicated the higher emotional recognition effects of eye area on dynamic images than mouth area. These results suggest that dynamic properties should be considered in emotional study with facial expressions for not only basic emotions but also complex emotions. However, we should consider the properties of emotion because each emotion did not show the effects of dynamic image equally. Furthermore, this study let us know which facial area shows emotional states more correctly is according to the feature emotion.

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Field Test: Effects of a Rail Joint on the Dynamic Behavior of Railway Bridge (철도차량의 동적거동에 대한 레일이음매의 영향)

  • Kim Hyun-Min;Oh Ji-Taek;Hwang Won-Sub;Cho Eun-Sang
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.1174-1179
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    • 2004
  • Field tests were conducted to investigate effects of a rail joint on the dynamic behavior of railway bridge. A four-span simpled supported plate girder bridge which has a rail joint on the third span was selected for tests. At the operating train loading, the induced vibration of the first and third span has been examined. The dynamic magnification ratio was used for quantitative analysis of impact effects caused by rail joint. The result of tests show that dynamic behavior of railway bridge picked up considerably due to a rail joint.

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Experimental study on wind-induced dynamic interference effects between two tall buildings

  • Huang, Peng;Gu, Ming
    • Wind and Structures
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    • v.8 no.3
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    • pp.147-161
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    • 2005
  • Two identical tall building models with square cross-sections are experimentally studied in a wind tunnel with high-frequency-force-balance (HFFB) technique to investigate the interference effects on wind loads and dynamic responses of the interfered building. Another wind tunnel test, in which the interfered model is an aeroelastic one, is also carried out to further study the interference effects. The results from the two kinds of tests are compared with each other. Then the influences of turbulence in oncoming wind on dynamic interference factors are analyzed. At last the artificial neural networks method is used to deal with the experimental data and the along-wind and across-wind dynamic interference factor $IF_{dx}$ & $IF_{dy}$ contour maps are obtained, which could be used as references for wind load codes of buildings.

Time-dependent effects on dynamic properties of cable-stayed bridges

  • Au, Francis T.K.;Si, X.T.
    • Structural Engineering and Mechanics
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    • v.41 no.1
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    • pp.139-155
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    • 2012
  • Structural health monitoring systems are often installed on bridges to provide assessments of the need for structural maintenance and repair. Damage or deterioration may be detected by observation of changes in bridge characteristics evaluated from measured structural responses. However, construction materials such as concrete and steel cables exhibit certain time-dependent behaviour, which also results in changes in structural characteristics. If these are not accounted for properly, false alarms may arise. This paper proposes a systematic and efficient method to study the time-dependent effects on the dynamic properties of cable-stayed bridges. After establishing the finite element model of a cable-stayed bridge taking into account geometric nonlinearities and time-dependent behaviour, long-term time-dependent analysis is carried out by time integration. Then the dynamic properties of the bridge after a certain period can be obtained. The effects of time-dependent behaviour of construction materials on the dynamic properties of typical cable-stayed bridges are investigated in detail.

A Dynamic Price Formation System and Its Welfare Analysis in Quantity Space: An Application to Korean Fish Markets

  • Park, Hoan-Jae
    • The Journal of Fisheries Business Administration
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    • v.41 no.2
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    • pp.107-133
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    • 2010
  • As policy makers are often concerned about dynamic effects of demand behavior and its welfare analysis by quantity changes, the paper shows how dynamic price formation systems can be built up to analyze the effect of policy options to the markets dynamically. The paper develops dynamic model of price formation for fish from the intertemporal optimization of the consumer choice problem. While the resulting model has a similar form of the error correction types of dynamic price formation system, it provides the rational demand behavior contrary to the myopic behavior of error correction demand models. The paper also develops appropriate tools of dynamic welfare analysis in quantity space using only short-run demand estimates both theoretically and empirically as a first attempt in the literature of price formation and fisheries. The empirical results of Korean fish markets show that the dynamic model and the welfare measures are reasonably plausible. The methodology and theory of this research can be applied and extended to the commodity aggregation, dynamic demand estimation, and dynamic welfare effects of regulation in the similar framework. Thus, it is hoped that this will enhance its applications to the demand-side economics.

The Effect of Strategic Intuition, Business Analytic, Networking Capabilities and Dynamic Strategy on Innovation Performance: The Empirical Study Thai Processed Food Exporters

  • AUJIRPONGPAN, Somnuk;HAREEBIN, Yuttachai
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.1
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    • pp.259-268
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    • 2020
  • The purpose of this study is to examine the predictive effects of intuition, business analytic, networking capabilities on innovation performance. The data was collected using a cross-sectional quantitative survey. A total of 292 useable responses were collected from Thai Processed Food Exporters (TPFE). The findings also indicated that the hypothesized relationships between the independent and dependent variables fit the empirical data. Specifically, it is revealed that strategic intuition, business analytic capabilities, network-based capabilities and dynamic capabilities had a direct effect on dynamic strategy. They also had statistically significant direct and indirect effects on dynamic performance. Based on the results of the correlation test, the researchers developed a dynamic capability model for the development of the dynamic performance of the operators, which included concepts, principles, methods, tools and guidelines. Furthermore, the impacts of intuition, business analytic, networking capabilities on dynamic strategy are also examined in this study. It makes a considerable contribution to the existing literature on dynamic strategy of TPFE, particularly in regards to explaining the performance.

Cumulative Effects of Trade Liberalization : The Case of Korean Manufacturing (무역자유화의 동태적 누적효과: 한국 제조업)

  • Park, Soonchan
    • Economic Analysis
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    • v.17 no.4
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    • pp.30-51
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    • 2011
  • Since the previous studies on the effects of trade liberalization implicitly assume that trade liberalization affects economic performance only in any point in time, they inevitably are static. Static evaluations fail to account for cumulative dynamic effects of trade liberalization that affect continuously economic performance. This paper tries to fill this gap of the previous studies in this field, estimating cumulative effects of trade liberalization on economic performance by employing an dynamic version of empirical model. One of important empirical issue is controlling bias from endogeneity. To resolve this problem, this paper employes system GMM that uses lagged first-differences as instruments for level equations and lagged levels as instruments for first-differences equations. It improves upon cross-section estimators because it controls for the potential bias induced by the omission of industry-specific effects and the endogeneity of all regressors. This study investigates the effects of trade liberalization in Korean manufacturing for the period from 1988 to 2005 and finds that cumulative dynamic effects of trade liberalization are present and bigger than static effects.