7,339 research outputs found
Iron-induced deep-level acceptor center in GaN/AlGaN high electron mobility transistors:Energy level and cross section
Dynamic Transconductance Dispersion Characterization of Channel Hot-Carrier Stressed 0.25<i>Ό</i>m AlGaN/GaN HEMTs
Scalar radiation from Chameleon-shielded regions
I study the profile of the Chameleon field around a radially pulsating mass.
Focusing on the case in which the background (static) Chameleon profile
exhibits a thin-shell, I add small perturbations to the source in the form of
time-dependent radial pulsations. It is found that the Chameleon field inherits
a time-dependence, there is a resultant scalar radiation from the region of the
source and the metric outside the spherically symmetric mass is not static.
This has several interesting and potentially testable consequences.Comment: 4 pages, 4 figures, slightly edited version matching the journal
versio
Fishing Across the Centuries: What Prospects for the Venice Lagoon?
Fishing has always been an important activity for those Venetians who live near the Lagoon, and it still enjoys an important economic and social role in the region. Over the last few years, however, the fishing industry has been subject to a profound transformation both in the reduction of the variety and the abundance of the species found in the lagoon, and in the change from a complex and well-structured type of activity to one which has become monospecialist, that is based principally on the fishing of the bivalve Tapes philippinarum (Adam & Reeve). The widespread diffusion of this bivalve and its considerable commercial value have resulted in an increased harvest, initially carried out by hand but now by more sophisticated methods which are capable of obtaining much higher yields. The social, economic and environmental problems resulting from this automated fishing have stimulated research into alternative strategies to manage the alieutic resources of the lagoon which will allow fishing to become a sustainable activity without inflicting long-term environmental damage. This present work will try and prepare the foundations for a system of eco-compatible management, based on an analysis of the functioning of the lagoonâs eco-system, defined as a paralic model, the observation of the traditional forms of fishing practiced over the centuries, a technical analysis of the present typology of lagoon fishing (fishing with fyke nets, âvallicolturaâ and fishing of fish fry for rearing, clam fishing (Tapes philippinarum), mussel culture) with particular reference to the species fished, the distribution of the activity throughout the year and the technology employed, to the productivity of the various fishing methods.Venice Lagoon, Fyke nets, Clam Fishing management, Fish Farming
Energy-Efficient selective activation in Femtocell Networks
Provisioning the capacity of wireless networks is difficult when peak load is significantly higher than average load, for example, in public spaces like airports or train stations. Service providers can use femtocells and small cells to increase local capacity, but deploying enough femtocells to serve peak loads requires a large number of femtocells that will remain idle most of the time, which wastes a significant amount of power.
To reduce the energy consumption of over-provisioned femtocell networks, we formulate a femtocell selective activation problem, which we formalize as an integer nonlinear optimization problem. Then we introduce GREENFEMTO, a distributed femtocell selective activation algorithm that deactivates idle femtocells to
save power and activates them on-the-fly as the number of users increases. We prove that GREENFEMTO converges to a locally Pareto optimal solution and demonstrate its performance using extensive simulations of an LTE wireless system. Overall, we find that GREENFEMTO requires up to 55% fewer femtocells to serve a given user load, relative to an existing femtocell power-saving procedure, and comes within 15% of a globally optimal solution
Women police leaders in Europe: a tale of prejudice and patronage
This paper provides rich and unique insights into the experiences of women police leaders across seven European regions. Drawing on interview data it presents accounts of womenâs experiences of pursuing advancement in policing and identifies informal and formal barriers to female advancement in European police organisations. Women police leaders report high levels of gender discrimination, obstruction and prejudice over the course of their careers. It argues that there are a number of subjective and informal criteria of âacceptabilityâ that shape womenâs experiences of promotion and that informal patronage is a strong basis from which strategic appointments are made within European police systems. The paper makes sense of the ways in which informal aspects of career progression function alongside formal promotion criteria to preserve men as the âidealâ candidates for police leadership positions, resulting in a preference for other men and the exclusion of women. The relevance of these findings is key to informing the future selection and development of police leaders in an increasingly complex police landscape
Philippa Hoskin. 'Robert Grosseteste and the 13th-century diocese of Lincoln: an English bishop's pastoral vision'. [Book Review]
- âŠ