• Title/Summary/Keyword: dynamic study

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Empirical Study of Dynamic Corporate Governance: New Evidence from Chinese-listed SMEs

  • Shao, Lin;Yu, Xiaohong
    • The Journal of Industrial Distribution & Business
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    • v.6 no.4
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    • pp.27-37
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    • 2015
  • Purpose - This study first explores the possible dynamic relationship between ownership structure and firm performance using a panel of 4,900 Chinese-listed small- and medium-sized enterprises (SMEs) from 1999 to 2012. Research design, data, and methodology - We address this issue through a dynamic panel model using a method of moments (GMM) technique and dynamic simultaneous equations to alleviate the potential endogenous problem: unobserved heterogeneity, simultaneity, and dynamic endogeneity. Results - Under the framework of dynamic endogeneity, firm performance has a significantly positive influence on ownership, but not vice versa. Ownership and performance can be explained by their owned lagged values, respectively. Moreover, intertemporal endogeneity exists among ownership, investment, and performance through the application of system dynamic equations, which implies that the relationship among ownership structure, investment, and firm performance is dynamic by nature. Conclusions - This study also significantly contributes to a better understanding of dynamic corporate governance by providing further empirical evidence from the largest capital market in the Asian region.

A Study on the Dynamic Stress Intensity Factor of Orthotropic Materials(I) (직교 이방성체의 동적 응력확대계수에 관한 연구(I))

  • 이광호;황재석;최선호
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.2
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    • pp.313-330
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    • 1993
  • The propagating crack problems under dynamic plane mode in orthotropic material is studied in this paper. To analyze the dynamic fracture problems in orthortropic material, it is important to know the dynamic stress components and dynamic displacement components around the crack tip. Therefore the dynamic stress components of dynamic stress field and dynamic displacement components of dynamic displacement field in the crack tip of orthotropic material under the dynamic load and the steady state in crack propagation were derived. When the crack propagation speed approachs to zero, the dynamic stress component and dynamic displacement components derived in this study are identical to the those of static state. In addition, the relationships between dynamic stress intensity factor and dynamic energy release rate are determinded by using the concept of crack closure closure energy with the dynamic stresses and represented according to physical properties of the orthotrophic material and crack speeds. The faster the crack velocity, the greater the stress value of stress components in crack tip. The stress value of the stress component of crack tip is greater when fiber direction coincides with the crack propagation than when fider direction is normal to the crack propagation.

Distribution Competitive Advantage of Vietnamese Fintech Enterprises and its Impact on Dynamic Capabilities

  • Nguyen Van THUY
    • Journal of Distribution Science
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    • v.22 no.1
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    • pp.61-67
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    • 2024
  • Purpose: The study has identified factors affecting dynamic capabilities and the distribution of competitive advantage under the impact of dynamic capabilities of Vietnamese fintech businesses. Research design, data, and methods: The method used in this study is a survey analysis of 120 Vietnamese fintech businesses to test the hypothesized relationships of the research model as well as evaluate its effectiveness. The study uses the Cronbach alpha analysis, factor analyses, and structural equation modeling to assess the research's measurement and structural models. Results: Research results show that 3 critical success factors: "Capacity to develop financial service ideas," "Ability to develop a platform," and "Business capacity" have a positive impact on "Dynamic capabilities." In addition, the study also evaluates the effect of "dynamic capabilities" on the "competitive advantage" of fintech businesses. Conclusion: Theoretically, this result contributes to discovering new, specific factors affecting the dynamic capabilities of fintech businesses. In practice, the research results are empirical evidence of the distribution of competitive advantages of Vietnamese Fintech businesses and their impact on dynamic capabilities.

An Evaluation Study on the Dynamic Stability of High Speed Railway Bridges (고속철도교량의 동적안정성 평가연구)

  • Bang, Myung-Seok;Chung, Guang-Mo
    • Journal of the Korean Society of Safety
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    • v.27 no.4
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    • pp.43-49
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    • 2012
  • In the design of high speed railway bridges is important a impact factor as a tool of assessing the dynamic capacitys of bridges. However, the impact factor(or dynamic amplification factor, DAF) of high speed railway bridges may essentially be changeable because the dynamic response is affected by the long train length(380 m), number of axles and high speed velocity(300 km/h)(Korea Train eXpress: KTX). Therefore, on this study will be examined the dynamic capacity and stability of the typical PSC Box Girder of high speed railway bridge. At first, the static/dynamic analysis is performed considering the axle load line of KTX based upon existing references. Additionally, the KTX moving load is transformed into the dynamic time series load for conducting various parameter studies like axle length, analytical time increment, velocity of KTX. The time history analysis is repeatedly performed to get maximum dynamic responce by varying axle load length, analytical time increment, velocity of KTX. The study shows that dynamic analysis has resonable results with optimal axle load length(0.6 m) and time increment(0.01 sec.) and maximum DAF and dynamic resonance happens at 270 km/h velocity of KTX.

Study for Dynamic Modulus Change Measurement of Permeable Asphalt Mixtures with Various Porosity using Non-Destructive Impact Wave (충격공진시험을 이용한 다양한 공극률을 가진 투수성 아스팔트 혼합물의 동탄성계수 변화 측정에 관한 연구)

  • Jang, Byung Kwan;Yang, Sung Lin;Mun, Sung Ho
    • International Journal of Highway Engineering
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    • v.15 no.3
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    • pp.65-74
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    • 2013
  • PURPOSES: This study is to evaluate the dynamic modulus changes of permeable asphalt mixtures by using non-destructive impact testing method and to compare the dynamic moduli of permeable asphalt mixtures through repeated freezing and thawing conditions. METHODS: For the study, non-destructive impact testing method is used in order to obtain dynamic modulus of asphalt specimen and to confirm the change of dynamic modulus before and after freezing and thawing conditions. RESULTS : This study has shown that the dynamic moduli of asphalt concrete specimens consisting of 10%, 15% and 20% porosity are reduced by 11.851%, 1.9564%, 24.593% after freezing and thawing cycles. CONCLUSIONS : Non-destructive impact testing method is very useful and has repeatability. Specimen with 15% porosity has high durability than others.

Numerical study of dynamic buckling for plate and shell structures

  • Liu, Z.S.;Lee, H.P.;Lu, C.
    • Structural Engineering and Mechanics
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    • v.20 no.2
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    • pp.241-257
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    • 2005
  • A numerical approach combining the finite element method with two different stability criteria namely the Budiansky and the phase-plane buckling criteria is used to study the dynamic buckling phenomena of plate and shell structures subjected to sudden applied loading. In the finite element analysis an explicit time integration scheme is used and the two criteria are implemented in the Finite Element analysis. The dynamic responses of the plate and shell structures have been investigated for different values of the plate and shell imperfection factors. The results indicate that the dynamic buckling time, which is normally considered in predicting elasto-plastic buckling behavior, should be taken into consideration with the buckling criteria for elastic buckling analysis of plate and shell structures. By selecting proper control variables and incorporating them with two dynamic buckling criteria, the unique dynamic buckling load can be obtained and the problems of ambiguity and contradiction of dynamic buckling load of plate and shell structure can be resolved.

Computer simulation for dynamic wheel loads of heavy vehicles

  • Kawatani, Mitsuo;Kim, Chul-Woo
    • Structural Engineering and Mechanics
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    • v.12 no.4
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    • pp.409-428
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    • 2001
  • The characteristics of dynamic wheel loads of heavy vehicles running on bridge and rigid surface are investigated by using three-dimensional analytical model. The simulated dynamic wheel loads of vehicles are compared with the experimental results carried out by Road-Vehicles Research Institute of Netherlands Organization for Applied Scientific Research (TNO) to verify the validity of the analytical model. Also another comparison of the analytical result with the experimental one for Umeda Entrance Bridge of Hanshin Expressway in Osaka, Japan, is presented in this study. The agreement between the analytical and experimental results is satisfactory and encouraging the use of the analytical model in practice. Parametric study shows that the dynamic increment factor (DIF) of the bridge and RMS values of dynamic wheel loads are fluctuated according to vehicle speeds and vehicle types as well as roadway roughness conditions. Moreover, there exist strong dominant frequency resemblance between bounce motion of vehicle and bridge response as well as those relations between RMS values of dynamic wheel loads and dynamic increment factor (DIF) of bridges.

The Immediate Effect of Static and Dynamic Stretching on Flexibility of Hamstring, Dynamic Balance Ability, Function of Lower Extremity: Randomized Controlled Trial

  • Ho Jin Shin;Eun-Ji Kim;Shin Young Kim
    • The Journal of Korean Physical Therapy
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    • v.35 no.5
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    • pp.125-131
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    • 2023
  • Purpose: This study examined the acute effects of static and dynamic stretching on the flexibility of the hamstring, dynamic balance ability, and function of the lower extremities in healthy adults. Methods: Thirty participants were assigned randomly to three groups: static stretching group (SSG), basic dynamic stretching group (BDSG), and 5 sec dynamic stretching group (5DSG). SSG performed three sets of 30 seconds of static stretching. BDSG performed a single-leg deadlift (SLD) at the same time as SSG, and 5DSG performed SLD held for five seconds. Hamstring flexibility, dynamic balance ability, and lower extremity function were evaluated before and after intervention. Results: The hamstring flexibility significantly improved in all groups (p<0.05). The dynamic balance ability improved significantly after intervention in all groups except BDSG in the anterior direction (p<0.05). There were significant differences in the posterolateral and posteromedial direction in all groups. The function of the lower extremity showed significant improvement over time only in BDSG (p<0.05). Conclusion: This study suggested that basic dynamic stretching and 5 sec dynamic stretching positively affect the hamstring flexibility, dynamic balance ability, and lower extremity function. Therefore, it is recommended to include dynamic stretching in a program for improving the hamstring flexibility, dynamic balance ability, and the lower extremity function. In addition, it is recommended to apply it at different times depending on the purpose.

Comparative Study on the Results of Seismic Design by Dynamic Analysis Method (동적 해석법을 이용한 내진설계 결과의 비교 고찰)

  • 이성우;노홍식;심규점
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1991.10a
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    • pp.81-89
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    • 1991
  • Recently increasing number of highrise buildings are aseismically designed by dynamic analysis method. To perform comparative study on the results of seismic design by dynamic analysis method, five-to thirty-story building models of ductile moment resisting frames and braced frames are considered. Base shears of these models using the spectrum of equivalent static method in the current Korean code and the ones of dynamic analysis method in the UBC-88 code are compared. Based on this study design spectra to be used in the dynamic analysis in Korea are proposed and the results are compared.

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A Study on the Chatter Analysis & Dynamic Stability of Drilling Mchine (드릴링 M/C의 Chatter 해석과 동적안정성에 관한 연구)

  • Park, Jong-Kweon;Lee, Hu-Sang
    • Journal of the Korean Society for Precision Engineering
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    • v.6 no.2
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    • pp.77-87
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    • 1989
  • This study is carried out to estimate the influence of cutting speed on the dynamic stability of a drilling machine. The theoretical stabilityu chart is constructed by using the measurd dynamic characteristics of the drilling machine. The critical cutting width and speed predicted from the stability chart show excellent agreements with those measured. Therefore it is confirmed that the analysis technique used in this study is useful for the prediction of the dynamic instability and improvement of the dynamic characteristics of drilling machines.

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