5,769 research outputs found
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
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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 women’s 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 ‘acceptability’ that shape women’s 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 ‘ideal’ 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
Kinematic and Dynamic Study of Cam Mechanisms for Bottling Machines
The main objective of this study is to analyze and optimize the cam mechanisms of the cork capper station currently in use for wine bottling machines. For each machine model considered, current cam profiles and corresponding real trajectories performed during operation are analyzed. Subsequently, various alternative laws of motion are tested to implement the same process, respecting the same precision points but modifying other parts of trajectory to improve machine dynamic performances. A series of tests carried out on a reconfigurable prototype and using different types of cork have made it possible to verify the effectiveness of the new laws of motion and to obtain the load acting on the machine at different operating speeds
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The gendering of violent crime: towards a human rights approach
This article reveals the diverse threats violent masculinities pose to human rights, especially females, in view of the idea that 'all things are equal now' between the genders. In the UK the Human Rights Act (1998) has sustained existing safeguards for the mainly male perpetrators of violence, but the needs of some female victims of domestic violence remain unmet. Contemporaneously, mainly female crime victims are vulnerable to violations of their basic human rights. The analysis in this paper identifies and interrogates the negative consequences of the principles of modernisation and six drivers of crime control underpinning government approaches since the late 1990s to dealing with violence against women in the context of general approaches to victimisation. Alongside issues relating to the receding influence of the state our argument is that a human rights-informed approach reveals not only the deficiencies and contradictions of government policy affecting change, but provides a vehicle for embedding a more comprehensive way of safeguarding human rights in practice
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