293 research outputs found
Recent micro-earthquake activity at Northern Evoikos gulf, Central Greece
During the last 4 months of 1999, the Institute of Geodynamics, of the National Observatory of Athens, deployed in the area of north Evoikos gulf, a local seismic network of 5 digital stations equipped with sensitive 3-components seismometers. The recorded micro-earthquakes, located in the upper part of the crust, show that there is significant seismic activity in the area of northern Evoikos gulf. This activity could be correlated not only with the main faults of the area, which are the Atalanti fault and the fault running parallel to the coasts of Evia island but also with other faults which are assumed to be, till now, less active or not so important
Lessons learnt from mining meter data of residential consumers
Tracking end-users' usage patterns can enable more accurate demand forecasting and the automation of demand response execution. Accordingly, more advanced applications, such as electricity market design, integration of distributed generation and theft detection can be developed. By employing data mining techniques on smart meter recordings, the suppliers can efficiently investigate the load patterns of consumers. This paper presents applications where data mining of energy usage can derive useful information. Higher demands, on one side, and the energy price increase on the other side, have caused serious issues with regards to electricity theft, especially among developing countries. This phenomenon leads to considerable operational losses within the electrical network. In order to identify illegal residential consumers, a new method of analysing and identifying electricity consumption patterns of consumers is proposed in this paper. Moreover, the importance of data mining for analysing the consumer's usage curves was investigated. This helps to determine the behaviour of end-users for demand response purposes and improve the reliability and security of the electricity network. Clustering load profiles for large scale energy datasets are discussed in detail
Tsunami hazard assessment in the Ionian Sea due to potential tsunamogenic sources – results from numerical simulations
In spite of the fact that the great majority of seismic tsunami is generated in ocean domains, smaller basins like the Ionian Sea sometimes experience this phenomenon. In this investigation, we study the tsunami hazard associated with the Ionian Sea fault system. <br><br> A scenario-based method is used to provide an estimation of the tsunami hazard in this region for the first time. Realistic faulting parameters related to four probable seismic sources, with tsunami potential, are used to model expected coseismic deformation, which is translated directly to the water surface and used as an initial condition for the tsunami propagation. <br><br> We calculate tsunami propagation snapshots and mareograms for the four seismic sources in order to estimate the expected values of tsunami maximum amplitudes and arrival times at eleven tourist resorts along the Ionian shorelines. <br><br> The results indicate that, from the four examined sources, only one possesses a seismic threat causing wave amplitudes up to 4 m at some tourist resorts along the Ionian shoreline
Fantasies of subjugation: a discourse theoretical account of British policy on the European Union
The decision by the UK government to hold a referendum on Britain’s membership of the European Union (EU) marks an important development in policy towards the EU. Policy changes of this kind must be understood in the historical and political context in which they occur. This includes the framing of the policy issues within public discourse. In the UK, policies are formed in a discursive environment which is overwhelmingly hostile towards the EU. Debates are structured by a predominantly Euroskeptic discourse which emphasizes the UK’s separation and heterogeneity from the rest of the EU. Drawing on the logics of critical explanation, this article examines the structure and affective power of Euroskeptic discourses which dictate the terms of the EU debate. It presents a case study of the recent EU treaty revision process, culminating in the Treaty of Lisbon. In so doing, it enables a deeper understanding of recent policy developments
Proučavanje seizmičkog zoniranja na području Grčke na osnovi magnitude najbolje opažljivog potresa
The Greek seismicity file developed by Makropoulos and Burton (1981) for earthquakes up to 1978 and extended up to 1983 (Makropoulos et al., 1986), is examined in terms of magnitude frequency using Gumbel’s third type asymptotic distribution of extreme values. The forecasting parameters are obtained by subdividing Greek seismicity in a cellular manner. Combination of the Gumbel III earthquake occurrence statistics for each cell with acceleration attenuation law leads to perceptibility curves which give the probability of perceiving specific acceleration levels from each earthquake magnitude up to local upper bound magnitude w. These curves show a peak probability which occurs at similar magnitudes defined as the “most perceptible” earthquake. The range of these “most perceptible” earthquake magnitudes is for an Ms of about 5.3 to 7.2.
The results are presented as contouring maps for two average depths of 10 km and 20 km respectively. The features of the contoured perceptibility maps are compatible with existing hazard maps of Greece based on different approaches. This, coupled with the fact that these values may be used as a criterion for choosing engineering design time histories, shows the usefulness of the method for seismic zoning problems
Possible relationship between Seismic Electric Signals (SES) lead time and earthquake stress drop
Stress drop values for fourteen large earthquakes with MW ≥ 5.4 which occurred in Greece during the period 1983–2007 are available. All these earthquakes were preceded by Seismic Electric Signals (SES). An attempt has been made to investigate possible correlation between their stress drop values and the corresponding SES lead times. For the stress drop, we considered the Brune stress drop, ΔσB, estimated from far field body wave displacement source spectra and ΔσSB derived from the strong motion acceleration response spectra. The results show a relation may exist between Brune stress drop, ΔσB, and lead time which implies that earthquakes with higher stress drop values are preceded by SES with shorter lead time
Pythagoras project: Development of an innovative training package on Indoor Environment Quality
The aim of the Pythagoras project is the development and assessment of Greek national training material in the sector of indoor environmental quality. The need for education in this specific sector is dictated by the significant indoor environment deterioration and associated health hazards, which are caused by low ventilation levels, combined with the use of many modern building materials that aggravate pollutants emissions. Early in the project, a review is undertaken of the international literature and the syllabuses of foreign research and educational institutions active in indoor environment quality issues. At the same time, the requirements of the Greek educational and broader society, related to issues of indoor pollution and health, are determined. A training methodology is consequently developed, with the objective to optimally cover all the parameters associated with the indoor environment quality, for trainees of various disciplines. The training material is produced both in printed (book) and integrated electronic (e-learning) format. Additionally, four seminars are organized covering the respective sections of the training package. The training package is being assessed both by the trainees but also by international experts in the sector of indoor environment quality
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A Test of a Strong Ground Motion Prediction Methodology for the 7 September 1999, Mw=6.0 Athens Earthquake
We test a methodology to predict the range of ground-motion hazard for a fixed magnitude earthquake along a specific fault or within a specific source volume, and we demonstrate how to incorporate this into probabilistic seismic hazard analyses (PSHA). We modeled ground motion with empirical Green's functions. We tested our methodology with the 7 September 1999, Mw=6.0 Athens earthquake, we: (1) developed constraints on rupture parameters based on prior knowledge of earthquake rupture processes and sources in the region; (2) generated impulsive point shear source empirical Green's functions by deconvolving out the source contribution of M < 4.0 aftershocks; (3) used aftershocks that occurred throughout the area and not necessarily along the fault to be modeled; (4) ran a sufficient number of scenario earthquakes to span the full variability of ground motion possible; (5) found that our distribution of synthesized ground motions span what actually occurred and their distribution is realistically narrow; (6) determined that one of our source models generates records that match observed time histories well; (7) found that certain combinations of rupture parameters produced ''extreme'' ground motions at some stations; (8) identified that the ''best fitting'' rupture models occurred in the vicinity of 38.05{sup o} N 23.60{sup o} W with center of rupture near 12 km, and near unilateral rupture towards the areas of high damage, and this is consistent with independent investigations; and (9) synthesized strong motion records in high damage areas for which records from the earthquake were not recorded. We then developed a demonstration PSHA for a source region near Athens utilizing synthesized ground motion rather that traditional attenuation. We synthesized 500 earthquakes distributed throughout the source zone likely to have Mw=6.0 earthquakes near Athens. We assumed an average return period of 1000 years for this magnitude earthquake in the particular source zone, thereby having simulated a catalog of ground motion for a period of 500,000 years. The distribution of traditional ground motion parameters of peak acceleration or spectral ordinates then becomes the synthesized record from which we develop hazard curves in the form of the annual probability of exceedance. This approach replaces the aleatory uncertainty that current PSHA studies estimate by regression of empirical parameters from the worldwide database with epistemic uncertainty on what specific sources actually do at specific sites. This is a fundamental change for PSHA and eliminates the need to extrapolate current empirical data that was gathered over about 50 years to represent values for 10{sup -3} annual probability of exceedance or less. This difference becomes especially significant for very sensitive structures that require estimates for 10{sup -5} or less exceedance
Horses for courses: exploring the limits of leadership development through equine-assisted learning
YesThis essay draws on insights taken from Lacanian psychoanalysis to rethink and resituate
notions of the self and subjectivity within the theory and practice of experiential leadership
development. Adopting an auto-ethnographic approach, it describes the author’s own
experience as a participant in a programme of equine assisted learning or ‘horse whispering’
and considers the consequences of human-animal interactions as a tool for self-development
and improvement. Through an analysis of this human/animal interaction, the essay presents
and applies three Lacanian concepts of subjectivity, desire and fantasy and considers their
form and function in determining the often fractured relationship between self and other that
characterises leader-follower relations
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