Identification Technique for Soil-Structure Analysis of the Ghirlandina Tower

Historical towers, in particular medieval towers, are an important part of cultural heritage, and their preservation mandates monitoring and detailed analyses of vulnerability under seismic actions as well as of their long-term performance. Certain aspects of structural nature are linked to the masonry behavior as a unilateral material, and other are aspects related to the interaction with soft soil conditions. This study aims to contribute to the aspects of preservation by exploring the role of the soil-structure interaction in predicting the behavior of the structures, with specific reference to the well-documented case history of the medieval Ghirlandina Tower (Modena, Italy). A significant contribution comes from an experimental identification analysis, performed in the presence of ambient vibration. A novel finding is that the soil structure interaction cannot be neglected, in contrast to most published identification analyses that usually assume the structure to have rigid constraint at base.     

Aboriginal Performance on Standardized Tests: Evidence and Analysis from Provincial Schools in British Columbia

Many indigenous populations are experiencing rural-to-urban migration. In making this transition, indigenous peoples are entering industrial societies where most income derives from wages or salaries, and formal educational achievement is crucial in determining economic prospects. This research analyzes the gap in test score results between Aboriginal and non-Aboriginal students in public schools in the Canadian province of British Columbia. It finds a strong effect of school quality, as measured by non-Aboriginal achievement, on Aboriginal achievement. It also finds a nonlinear negative relationship between Aboriginal achievement and the number of Aboriginal students in a school over the empirically observed range. It thus suggests a possible trade-off and dilemma between, on the one hand, policies that enable Aboriginal students to concentrate in a few schools able to provide a culturally sensitive curriculum and, on the other, policies to maximize Aboriginal academic achievement.     

CHALLENGING CERTAINTY: THE UTILITY AND HISTORY OF COUNTERFACTUALISM

Counterfactualism is a useful process for historians as a thought-experiment because it offers grounds to challenge an unfortunate contemporary historical mindset of assumed, deterministic certainty. This article suggests that the methodological value of counterfactualism may be understood in terms of the three categories of common ahistorical errors that it may help to prevent: the assumptions of indispensability, causality , and inevitability. To support this claim, I survey a series of key counterfactual works and reflections on counterfactualism, arguing that the practice of counterfactualism evolved as both cause and product of an evolving popular assumption of the plasticity of history and the importance of human agency within it. For these reasons, counterfactualism is of particular importance both historically and politically. I conclude that it is time for a methodological re-assessment of the uses of such thought-experiments in history, particularly in light of counterfactualism's developmental relatedness to cultural, technological, and analytical modernity.     

Scale, causality, complexity and emergence: rethinking scale's ontological significance

Scale remains a pivotal yet highly contentious concept in geography. I survey the lively discussions engaged in recently by many critical/radical geographers regarding the theoretical status of scale. While these discussions have been intellectually fruitful, I argue that much more needs to be said. Drawing from complex systems theory, I argue that scale should be understood as an ontological category essential to understanding causality. Revalorising Aristotle's four categories of cause – formal, final, material and efficient – from two centuries of positivist thinking facilitates this endeavour. Research on the relationship between university-based poultry scientists and the poultry industry illustrates the explanatory potential of poly-scalar analysis.     

On the frontiers of Europe,not all musket balls were round; accuracy and penetration of various types of military small arms munitions from the mid seventeenth century to the early eighteenth century

While many armies began to adopt large calibre weapons in the seventeenth and eighteenth century, frontier conflicts in the outer reaches of Europe and in North America have provided evidence for the retention of smaller calibres, particularly evidenced through the archaeological recovery of ammunition. Present within these assemblages are various forms of non-standard ammunition — i.e. not round — including bullets with casting sprues still attached at the time of firing. This paper provides an assessment of the combat effectiveness of these various types of ammunition through a series of firing tests using replicated ammunition.     

我国城市化与经济增长的因果关系研究——基于1978-2007年东、中、西部、东北地区面板数据

本文选取1978-2007年中国30个省市的面板数据,运用面板单位根检验、面板协整检验及误差修正模型对我国城市化与经济增长的因果关系进行了检验。实证结果表明:从全国来看,城市化是经济增长的长短期原因,但经济增长是城市化的长短期原因均无法得到证实;东部地区的城市化与经济增长的长短期均互为因果关系;对于中、西部、东北地区而言,城市化是经济增长的长期原因,但不是其短期原因,长短期内经济增长都不是城市化的原因。     

旅游业与我国经济增长关系的实证分析

旅游业与国民经济增长之间的关系一直是有关学者研究的对象,这也导致了对旅游业地位的不同认识。本文利用历史数据对改革开放以来中国居民旅游消费支出与经济增长之间的关系作出判断,认为我国旅游业与经济增长之间并不存在稳定的因果关系。文章对产生这种现象的原因进行了分析,并提出了相关政策建议。     

察同察异求规律:比较史学的追求

最早倡导比较史学的社会哲学家孔德和密尔以及被誉为比较史学名家的马克·布洛赫都认为,比较史学的功用在于察同察异求规律。然而,由于他们都未能找到决定历史进程的“首要因素”或“普遍原因”,终究未能实现探求规律的抱负。只有马克思主义历史唯物主义,才提供了实现这一抱负的根本途径。     

Analysis of the Out-Of-Plane Seismic Behavior of Unreinforced Masonry: A Literature Review

Although the issue of the out-of-plane response of unreinforced masonry structures under earthquake excitation is well known with consensus among the research community, this issue is simultaneously one of the more complex and most neglected areas on the seismic assessment of existing buildings. Nonetheless, its characterization should be found on the solid knowledge of the phenomenon and on the complete understanding of methodologies currently used to describe it. Based on this assumption, this article presents a general framework on the issue of the out-of-plane performance of unreinforced masonry structures, beginning with a brief introduction to the topic, followed by a compact state of art in which the principal methodologies proposed to assess the out-of-plane behavior of unreinforced masonry structures are presented. Different analytical approaches are presented, namely force and displacement-based, complemented with the presentation of existing numerical tools for the purpose presented above. Moreover, the most relevant experimental campaigns carried out in order to reproduce the phenomenon are reviewed and briefly discussed.