EVALUATION OF ACCIDENTAL ECCENTRICITY IN BUILDINGS DUE TO ROTATIONAL COMPONENT OF EARTHQUAKE

This study adopts a random procedure in the evaluation of the effect of the rotational component of earthquake on the accidental eccentricity of symmetric and asymmetric buildings. The spectral density function of the rotational component of earthquake acceleration (about the vertical axis) is obtained on the basis of the spectral density function of the horizontal component of earthquake acceleration. The rotational component of an earthquake can increase the response of the structure. The degree of the increase is highly dependent upon the dynamic characteristics of the system and the rotational component of the earthquake. To bring this increase under consideration, seismic codes represent a parameter referred to as accidental eccentricity, as a part of the design eccentricity. The purpose of the present study is to estimate the value of this increase and to make appropriate suggestions based on frequency domain analysis.     

NONLINEAR SHAKE TABLE IDENTIFICATION AND CONTROL FOR NEAR-FIELD EARTHQUAKE TESTING

The primary focus of a structural shake table system is the accurate reproduction of acceleration records for testing. However, many systems deliver variable and less than optimal performance, particularly when reproducing large near-field seismic events that require extreme table performance. Improved identification and control methods are developed for large hydraulic servo-actuated shake table systems that can exhibit unacceptable tracking response for large, near-field seismic testing. The research is presented in the context of a 5-tonne shake table facility at the University of Canterbury that is of typical design. The system is identified using a frequency response approach that accounts for the actual magnitudes and frequencies of motion encountered in seismic testing. The models and methods developed are experimentally verified and the impact of different feedback variables such as acceleration, velocity and displacement are examined.

The methods show that shake table control in testing large near-field seismic events is often a trade off between accurate tracking and nonlinear velocity saturation of the hydraulic valves that can result in severe acceleration spikes. Control methods are developed to improve performance and include both acceleration and displacement feedback to reduce the acceleration spikes, and record modification, where the reference signal is modified to conform to the shake table's operational parameters. Results show record modification gives exact tracking for near-field ground motions, and optimal system response for reference signals with velocity components greater then the system capabilities. Overall, the research presents a methodology for simple effective identification, modelling, diagnosis and control of structural shake table systems that can be readily generalised and applied to any similar facility.     

THE BOVEC (SLOVENIA) EARTHQUAKE,APRIL 1998: PRELIMINARY QUANTITATIVE ASSOCIATION AMONG DAMAGE,GROUND MOTION AMPLIFICATION AND BUILDING FREQUENCIES

After the 5.6 earthquake that struck Slovenia on Easter day in 1998, a quick survey was organised to perform a series of field measurements aimed at estimating site amplification. The possibility of recording aftershocks in the immediate aftermath of the main event improves the reliability of Nakamura's technique. The most affected sites that were sampled are located in the areas of Bovec and Dreznica. The damage pattern shows strong variations on short scale range. The typology of the buildings is very similar over the entire area being surveyed, and it is therefore likely that most of the variation could be attributed to site amplification effects. Local geology appears to be the dominant factor in most of the damage observed, and it can be qualitatively linked to empirical amplification functions obtained with Nakamura's technique. The damage enhancement between neighbouring sites is well correlated with amplification in a frequency range relevant to building vibration.     

More than Samad in Oman: Iron Age pottery from Şuhār and Khor Rorī1

The publication of field work in central Oman has lagged behind the excavations themselves. Whereas the pioneer archaeologists in Oman could identify sites and finds only as “Iron Age”, the work of the past 10 years has enabled a clear conceptual distinction to be made between the Early and Late Iron Age assemblages, as well as their regional characters. Using as a point of departure the Samad Complex, for which most intact contexts exist, the less well-known Late Iron Age of the North and South of Oman is compared by means of newly recorded material from old excavations, there, as well as from a recent survey. There were contacts between central Oman and the South Province, Dhofar although such are elusive. Despite, archaeologically speaking, undeniable trade and ethnic contacts with the outside world, central Oman has a distinctive character of its own which has not been properly credited by specialists of the final Pre-Islamic Period.     

The futures past of the Women,Peace and Security agenda

The Women, Peace and Security (WPS) agenda has developed at the United Nations over the course of the past 15 years, and there have been critical engagements with it for nearly as long. In this article, we first take stock of the operationalization of the WPS agenda, reviewing its implementation across a number of sectors. In the second section, we expose the tensions that have marked the WPS agenda from the start. With others, we argue that there has been a narrowing of the agenda's original scope, reducing it to the traditional politics of security rather than reimagining what security means. We highlight this reduction primarily through an analysis of the tension between the ‘participation’ and ‘protection’ pillars of the agenda. Further, we argue that the WPS agenda faces a current challenge in terms of the actors entrusted with it. Although in some ways involving civil society, the consolidations and implementation of WPS principles at the national and international levels have become increasingly state‐centric. Third, we imagine some possible futures of the agenda, from a trajectory characterized by increasing marginalization or even irrelevance, to new avenues like the emergent, albeit tentative, ‘Men, Peace and Security’ agenda. We close with an argument for a revival of the WPS agenda beyond a fixation on states, beyond a narrow heteronormative or essentialist focus on the ‘Women’ of the WPS resolutions, and moving towards the radical reimagining of security as peace that inspired the original architects of these important resolutions.     

La dynamique spatiale des marchés locaux de l'emploi au sein du champ métropolitain de Québec, 1981–2001

Spatial Dynamics of Local Labour Markets in the Québec City Metropolitan Field, 1981–2001
This research analyzes the spatial dynamics (from 1981 to 2001) of local labour markets at an infra-regional scale, namely the Québec metropolitan field, with particular emphasis on interactions between the metropolitan region and its hinterland. It seeks to better understand the factors underlying this evolution. Centrographic analyses were performed to characterize the evolution of the spatial configuration of local labour markets (displacement of gravity centre, shape change, evolution of dispersion indices and of workforce preferential distribution axes). Between 1981 and 2001, almost all employment poles experienced an increase in the mean-distance tied to their recruitment area, that being particularly true for peri-metropolitan poles which employ an increasing part of their workforce inside the metropolitan labour basin, where a more qualified and diversified labour force is available; thus, giving rise to significant reverse commuting. In addition to the influence of distance to metropolitan area, a multiple regression model shows that factors such as manufacturing specialization and employment growth within job centres also play a crucial role in the spatial dynamics of local labour markets in the Québec City metropolitan field.     

Universal vision or bounded rationality?

William Walker's article takes a strongly universalist view of the requirements of nuclear order. It finds recent American administrations deliberately unwilling to maintain international confidence in the necessary collective narrative of eventual universal nuclear disarmament, so causing a crisis of confidence in the Non Proliferation Treaty regime. This commentary examines how far realistically different recent US policies and declarations could have avoided such problems, given certain underlying realities and dynamics surrounding the management of nuclear weapons. It also questions how indispensable abstract universalism will be in containing future nuclear proliferation.