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

Parametrised modified gravity and the CMB Bispectrum

We forecast the constraints on modified theories of gravity from the cosmic microwave background (CMB) anisotropies bispectrum that arises from correlations between lensing and the Integrated Sachs-Wolfe effect. In models of modified gravity the evolution of the metric potentials is generally altered and the contribution to the CMB bispectrum signal can differ significantly from the one expected in the standard cosmological model.We adopt a parametrised approach and focus on three different classes of models: Linder's growth index, Chameleon-type models and f(R) theories. We show that the constraints on the parameters of the models will significantly improve with future CMB bispectrum measurements.Comment: 7 pages, 6 figure

Push & Pull: autonomous deployment of mobile sensors for a complete coverage

Mobile sensor networks are important for several strategic applications devoted to monitoring critical areas. In such hostile scenarios, sensors cannot be deployed manually and are either sent from a safe location or dropped from an aircraft. Mobile devices permit a dynamic deployment reconfiguration that improves the coverage in terms of completeness and uniformity. In this paper we propose a distributed algorithm for the autonomous deployment of mobile sensors called Push&Pull. According to our proposal, movement decisions are made by each sensor on the basis of locally available information and do not require any prior knowledge of the operating conditions or any manual tuning of key parameters. We formally prove that, when a sufficient number of sensors are available, our approach guarantees a complete and uniform coverage. Furthermore, we demonstrate that the algorithm execution always terminates preventing movement oscillations. Numerous simulations show that our algorithm reaches a complete coverage within reasonable time with moderate energy consumption, even when the target area has irregular shapes. Performance comparisons between Push&Pull and one of the most acknowledged algorithms show how the former one can efficiently reach a more uniform and complete coverage under a wide range of working scenarios.Comment: Technical Report. This paper has been published on Wireless Networks, Springer. Animations and the complete code of the proposed algorithm are available for download at the address: http://www.dsi.uniroma1.it/~novella/mobile_sensors

Integrating religious engagement into diplomacy: challenges and opportunities

The last few years have witnessed a flurry of interest and activity around religion and religious engagement in diplomatic circles on both sides of the Atlantic. In 2013, the US State Department established a new Office of Faith-Based Community Initiatives as part of a broader national strategy on religious leadership and faith community engagement led by the White House’s National Security Council. Within the same year, the European Union issued new guidelines on the promotion and protection of freedom of religion or belief; the Canadian Department of Foreign Affairs, Trade and Development opened a new office focused on similar issues; and the French Foreign Ministry sponsored a major conference on the question of religion and foreign policy with a keynote address delivered by Foreign Minister Laurent Fabius

Migration and the challenges of Italian multiculturalism

The migration crisis is analysed here in the context of the fundamental challenges which Italy faces through becoming a country of immigration in a period of recession. It is argued that there has been no serious debate in Italy on multiculturalism, or on religious freedom, despite the growing socio-cultural and religious diversity arising from population movements and international conflict. The analysis begins with the Italian government’s attempts in 2015 to deal with migration and diversity, and the associated domestic conflicts at the levels of both party politics and society. This leads to a discussion of the meaning of the Christian/Catholic identity of the country in its changed conditions. The external dimension of Italian politics is examined in terms of both Rome’s impatient calls for EU help and the weak political position of Italy in relation to the root causes of migration, whether through intervention or diplomatic influence

Determinants of travel mode choice in Europe: Results from a survey on routine mobility

Understanding the differences in travel behaviour across different countries underlined by trip and individual characteristics are paramount to develop effective policies to nudge a shift towards sustainable mobility. In this study we present a descriptive analysis of the results of a mobility household survey, collecting information on citizen travel behaviour, travel mode choices and the factors influencing them. The study involves five European countries: Hungary, Italy, Norway, Poland and Spain. Results describe how travel mode choice fluctuates with users’ heterogeneity and that different mobility transition policies receive different support from citizens. Instruments implying a direct financial cost are much less accepted than technology- and infrastructure-based policies. Support to policies such as road expansion is also observed. The transition in mobility should then have to deal with households’ beliefs to make them revise their travel behaviours. But the mobility transition is also closely linked to the city development and the distribution of workplace and grocery shopping in the cit