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41.
Edilberto Tiago de Almeida Raul da Mota Silveira Neto Roberta de Moraes Rocha 《Journal of regional science》2023,63(4):820-863
This paper provides evidence about location and colocation patterns of manufacturing entrepreneurship and spatial scope of agglomeration economies in the context of a developing country. Using microgeographic data for all Brazilian manufacturing activities and distance-based measures, we find clear patterns of colocalization between entrants and existing establishments, and that these patterns occur mainly at short distances. For activities presenting colocalization between entrants and existing establishments, our results also indicate that a greater number of incumbent establishments in a given location positively affects the number of entrant establishments that decide to locate there, an effect that attenuates rapidly with distance (generally disappearing after 5 km). This pattern of attenuation is robust to both the inclusion of a comprehensive set of controls for observable and unobservable local characteristics and the use of instrumental variables to address remaining endogeneity concerns. 相似文献
42.
连志丹 《华侨华人历史研究》2001,8(3):41-46
针对近年来祖国大陆海外华文教育快速发展带来的挑战 ,台湾当局在延续其历年经验性做法的基础上 ,以满足海外侨教现实需要为目标 ,注重以创新思维拓展侨教工作 ,采取各种更加灵活和有力的措施 ,多方面多渠道地扶持海外侨教工作。本文分析了台湾现阶段扶持海外侨教的主要措施 ,论述了其可资借鉴与参考之处。 相似文献
43.
Charlène Kermagoret Harold Levrel Antoine Carlier 《Scottish Geographical Journal》2014,130(3):188-206
AbstractIn France, the public acceptability of marine renewable energies and their impacts on ecosystem services (ES) involves questions about compensation for stakeholders, who may perceive some of their activities and interests to be modified. This paper seeks to understand how impacts on ES are perceived by institutional stakeholders and what is expected in terms of compensation. It also seeks to identify the communities of practice affected. We focus our study on the planned offshore wind farm in the bay of Saint-Brieuc. Our results show that institutional discourse is heterogeneous, depending on sensitivities, interests, and who or what the stakeholders surveyed represent or defend. Stakeholders' discourse can be interpreted on various gradients of perception. Six distinct communities of practice have been identified, based on the impacts perceived by institutional stakeholders. Lastly, we show that the community of practice seems to be a proper level at which to study perceptions and assess the no-net-loss goal. 相似文献
44.
The Internet is an interconnected network and cyber security requires collective action. How that action is organised has important implications for national security, including the defence against cyber attacks and malicious activities. This article explains the origins and institutionalisation of cyber security in Australia—particularly ‘civilian cyber security’. The authors trace the origin of Australia’s first computer emergency response team and explain how this organisational form spread from the USA. Through it, Australia helped enable international cooperation. Domestically, however, the authors argue that the Australian government has struggled with the delegation, orchestration and abdication of responsibility for civilian cyber security, underinvesting in civilian organisations while overrelying on military and intelligence agencies. The history of this organisational field provides valuable insight into how to improve national policy and operations for cyber security. 相似文献
45.
The vertical component of earthquake ground motion has generally been neglected in the earthquake-resistant design of structures. This is gradually changing due to the increase in near-source records obtained recently, coupled with field observations confirming the possible destructive effect of high vertical vibrations. In this paper, simple procedures are suggested for assessing the significance of vertical ground motion, indicating when it should be included in the determination of seismic actions on buildings. Proposals are made for the calculation of elastic and inelastic vertical periods of vibration incorporating the effects of vertical and horizontal motion amplitude and the cross-coupling between the two vibration periods. Simplified analysis may then be used to evaluate realistic vertical forces by employing the vertical period of vibration with pertinent spectra without resorting to inelastic dynamic analysis. Finally, a procedure is suggested for combining vertical and horizontal seismic action effects which accounts for the likelihood of coincidence, or otherwise, of peak response in the two directions. 相似文献
46.
T. PAULAY 《Journal of Earthquake Engineering》2013,17(3):273-308
Recent studies provided opportunities to review some of the principles, which have been used in the formulations of internationally accepted code-recommendations relevant to the seismic design of ductile buildings also subjected to torsional phenomena. With the progress of this study, features emerged which are considered to have contributed to a better understanding of structural behaviour. Moreover, the identification of deeply embedded fallacies, relevant to ductile response, suggested the introduction of some changes in seismic design strategies, yet not widely known or appreciated. Reasons for necessary re-interpretations of traditional structural properties, together with illustrative examples, demonstrating applications, rather than set code-type rules, are offered. 相似文献
47.
IUNIO IERVOLINO∗ GIOVANNI FABBROCINO GAETANO MANFREDI 《Journal of Earthquake Engineering》2013,17(6):927-945
National and international regulatory standards require industrial risk assessment, taking into account natural hazards including earthquakes, in the framework of Quantitative Risk Analysis (QRA). Seismic fragility analysis of industrial components may be carried out similarly as what has been done for buildings, even though some peculiar aspects require the development of specific tools. In the present paper a contribution to the definition of a rational procedure for seismic vulnerability assessment of standardised industrial constructions in a probabilistic framework is given. The method covers a range of components of the same structural type. Seismic reliability formulation for structures is used. Both seismic capacity and demand are considered probabilistic with the latter assessed by dynamic analyses. The application example refers to shell elephant foot buckling of unanchored sliding tanks. A regression-based method is applied to relate fragility curves to parameters varying in the domain of variables for structural design. 相似文献
48.
AHMED ELGAMAL TAO LAI RAMANA GUNTURI MOURAD ZEGHAL 《Journal of Earthquake Engineering》2013,17(4):545-566
Assessment of landfill seismic response necessitates the availability of reliable dynamic material properties. During the past decade, geophysical surveys and computational studies have been conducted to investigate the seismic response of the Operating Industries, Inc. (OII) landfill in Southern California. In this paper, a survey and summary of available research results is presented. In addition, a set of Oil input-output seismic records during six earthquakes is thoroughly analysed. Spectral analyses are conducted to shed light on the landfill dynamic response characteristics. A simple shear beam model is found to be useful in modelling the landfill resonant behaviour. System identification techniques are employed to estimate the landfill stiffness and damping properties. These properties are defined by minimising the difference between computed and recorded acceleration response spectra at the landfill top. The identified stiffness properties are found to be near the lower bound of those documented through geophysical measure-ments. Identified damping of about 5% (at resonance) is within the range of earlier investigations. Comparisons of the computed and recorded accelerations show: (I) effectiveness of a linear viscous shear beam model in simulating the landfill dynamic behaviour, for the recorded small to moderate levels of dynamic excitation (up to 0.26 g peak lateral acceleration), and (ii) potential of the employed system identification procedure for analysis of input-output seismic motions. 相似文献
49.
M. REZA GHAYAMGHAMIAN∗ 《Journal of Earthquake Engineering》2013,17(2):247-264
Different aspects of spectral analysis for site response evaluation are investigated in this study. The segmental cross-spectrum is proposed in spectral analysis of earthquake ground motions. The performance of segmental cross-spectrum in contrast with the conventional methods is investigated through the mathematical modelling, numerical analysis and application to earthquake data recorded at Chiba and Shinfuji downhole arrays in Japan. In analysis of earthquake data, the soil amplification function is identified using both uphole/downhole (U/D) and H/V spectral ratios. The advantage of seg-mental cross-spectrum is assessed by comparing identified amplification functions using different spectral methods and theoretical soil response. The reliability of site response estimations obtained by H/V spectral ratio using segmental cross- and Fourier spectra is also examined by means of cross-validation with the U/D spectral ratio of earthquake motion and theoretical soil response. Furthermore, the application of segmental cross-spectrum in nonlinear soil response is examined by comparing the amplification function of weak and strong motions for both methods. The results validate the advantage of segmental cross-spectrum in both linear and nonlinear soil response, particularly, when it used with H/V technique. 相似文献
50.
The role of soil-structure interaction (SSI) in the seismic response of structures is reex-plored using recorded motions and theoretical considerations. Firstly, the way current seismic provisions treat SSI effects is briefly discussed. The idealised design spectra of the codes along with the increased fundamental period and effective damping due to SSI lead invariably to reduced forces in the structure. Reality, however, often differs from this view. It is shown that, in certain seismic and soil environments, an increase in the fundamental natural period of a moderately flexible structure due to SSI may have a detrimental effect on the imposed seismic demand. Secondly, a widely used structural model for assessing SSI effects on inelastic bridge piers is examined. Using theoretical arguments and rigorous numerical analyses it is shown that indiscriminate use of ductility concepts and geometric relations may lead to erroneous conclusions in the assessment of seismic performance. Numerical examples are presented which highlight critical issues of the problem. 相似文献