Empirical Formulation for Estimating the Fundamental Frequency of Slender Masonry Structures

The fundamental frequency of a structure enables better assessment of its seismic demand for an efficient design and planning of its maintenance and retrofit strategy. The frequency is independent of the type of external loads, however, depends on structural stiffness, mass, damping and boundary conditions. In the case of slender masonry structures such as towers, minarets chimneys, and pagoda temples, it is influenced by mass and stiffness distribution, connection to adjacent structures, material properties, aspect ratio and slenderness ratio. In this present article, the data collected from various literature reviews on the slender masonry structures regarding dynamic, geometrical, and mechanical characteristics have been correlated to identify the major parameters influencing the fundamental frequency of such structures. The database has been used for developing an empirical formulation for predicting the fundamental frequency of such structures. The comparison between the experimental fundamental frequencies and the estimated fundamental frequencies are carried out in order to define reliability and accuracy of these empirical formulae.     

What drives the spatial wage premium in formal and informal labor markets? The case of Ecuador

This article investigates the incidence of agglomeration externalities in Ecuador, a small-sized, middle-income developing country. In particular, we analyze the role of the informal sector within these relations, since informal employment accounts for a significant part of total employment in the developing countries. Using individual level data and instrumental variable techniques, we investigate the impact of spatial externalities, in terms of population density, local specialization and urban size, on the wages of workers in Ecuadorian cities. The results show that spatial externalities matter also for a small developing country. Moreover, analysis of the interaction between spatial externalities and informality shows that, on average, workers employed in the informal sector do not enjoy significant benefits from agglomeration externalities. Finally, by investigating the possible channels behind spatial agglomeration gains we show that the advantages from agglomeration for formal sector workers may well be accounted for by better job-quality matches and, to a lesser extent, by learning externalities. For informal sector workers, our findings also suggest possible gains from job changes, which offset a penalty for remaining employed in the same occupation.     

Funerary practices and kinship in an Early Bronze Age society: a Bayesian approach applied to the radiocarbon dating of Argaric double tombs

The main aim of this paper is to test the hypothesis on kinship relations (affinity/marriage vs descent/consanguinity, and matrilocality) expressed in the funerary record of the El Argar Bronze Age society (South-east Iberia, 2200–1550 cal BCE), taking into account the absolute chronological dimension of double adult tombs. A set of 23 double tombs having radiocarbon dates for both skeletons were selected, and radiocarbon calibration and Bayesian probability analysis was conducted. The results support the ‘descent’ hypothesis, since for most of the cases the chronological distance between individuals buried together was larger than two decades. Finally, several guidelines for future research are suggested in order to overcome shortages in current chronological and archaeological data.     

The Scientific Trajectory of the French School of Proximity: Interaction- and Institution-based Approaches to Regional Innovation Systems

The multi-faceted concept of proximity is often used nowadays in many theoretical and empirical analyses. It mainly originates in some French regional scientists' attempt, in the early 1990s, to develop new conceptual and methodological avenues with a view to the study of the industrial and spatial dynamics. The wide diffusion of the resulting research findings is explained by the fact that these scholars realized early on that it was in their interest to collectively structure their works through the setting-up of a research group. The present paper sets out to outline the scientific and institutional trajectories of the French group “Proximity Dynamics”, while underlining the progressive broadening of its scientific and institutional dimensions, as well as the main theoretical research fields these trajectories have permitted to investigate.     

URBAN‐TO‐RURAL POPULATION GROWTH LINKAGES: EVIDENCE FROM OECD TL3 REGIONS*

The objective of this paper is to understand, from an international comparative perspective, how population growth in rural regions is affected by the relationship with their nearby urban centers. By means of a cross‐sectional analysis on OECD small regions (Territorial Level 3), the paper distinguishes spread effects—positive spillovers arising from urban growth—from the net effect of distance to nonrural places. The results show that spread effects outweigh backwash effects, so that rural regions benefit from growth in urban places. A rural region's distance from urban and intermediate regions has a negative effect on its population growth rate. Nevertheless, both the strength of this effect and the growth spillovers decline with distance, and this occurs relatively faster in Europe. The results further suggest that proximity to large urban areas has a higher positive influence than proximity to intermediate areas, but only outside Europe.     

The Quaternary fossil record of the genus Testudo in the Iberian Peninsula. Archaeological implications and diachronic distribution in the western Mediterranean

This paper explores the presence of tortoise remains and its meaning in Palaeolithic archaeological contexts. We focus on two topics: (1) the presence or absence of the genus Testudo from the Early Pleistocene to the Holocene in SW Europe; and (2) the relationship between Testudo and the palaeoclimatic and palaeoenvironmental conditions diachronically. In order to address this objective, we collected published and unpublished data from different sites on the eastern Iberian Peninsula. The results obtained by this study demonstrate that Testudo hermanni was the only tortoise present in this area until recent times and its presence in archaeological sites is almost always related to anthropic activities. Finally, the disappearance of Testudo from archaeological sites in some areas is related to climatic changes and events that occurred during the last stages of the Pleistocene.     

Investigation Techniques for the Seismic Response Assessment of Buildings Located in Historical Centers

ABSTRACT

It is an acknowledged fact that historical centers, given its significance from the cultural and architectural viewpoint, bring further challenges in terms of maintenance planning, survey, and safety assessment. The preparation of an adequate investigation plan and the extent of data to be collected is highly reliant on many aspects, such as the category of the architectonic asset, the importance of the heritage site, or the resources available, for example. In what regards the seismic response assessment of urban cultural heritage assets located in historical centers, the amount and detail of data also depend on this article, scale of assessment, and current state of conservation and occupation. Within this framework, this article provides an overview of the state of the art of investigation techniques currently used in survey operations, which are currently available for improving the knowledge level of urban cultural heritage assets within historical centers, as a supporting tool for the seismic response assessment of such singular assets. Finally, acknowledging the lack of accuracy when evaluating the seismic response of an asset enclosed in aggregate as an isolated structure, this article also focuses on the identification of the main particularities inherent to buildings enclosed in aggregate.