How dangerous are your smartphones? App usage recommendation with privacy preserving

With the rapid proliferation of mobile devices, explosive mobile applications (apps) are developed in the past few years. However, the functions of mobile apps are varied and the designs of them are not well understood by end users, especially the activities and functions related to user privacy. Therefore, understanding how much danger of mobile apps with respect to privacy violation to mobile users is becomes a critical issue when people use mobile devices. In this paper, we evaluate the mobile app privacy violation of mobile users by computing the danger coefficient. In order to help people reduce the privacy leakage, we combine both the user preference to mobile apps and the privacy risk of apps and propose a mobile app usage recommendation method named AppURank to recommend the secure apps with the same function as the “dangerous” one for people use. The evaluation results show that our recommendation can reduce the privacy leakage by 50%

Power consumption evaluation of circuit-switched versus packet-switched optical backbone networks

While telecommunication networks have historically been dominated by a circuit-switched paradigm, the last decades have seen a clear trend towards packet-switched networks. In this paper we evaluate how both paradigms perform in optical backbone networks from a power consumption point of view, and whether the general agreement of circuit switching being more power-efficient holds. We consider artificially generated topologies of various sizes, mesh degrees and not yet previously explored in this context transport linerates. We cross-validate our findings with a number of realistic topologies. Our results show that, as a generalization, packet switching can become preferable when the traffic demands are lower than half the transport linerate. We find that an increase in the network node count does not consistently increase the energy savings of circuit switching over packet switching, but is heavily influenced by the mesh degree and (to a minor extent) by the average link length

arch^{arch}PbMoO4 scintillating bolometer as detector to searches for the neutrinoless double beta decay of 100^{100}Mo

The archPbMoO4 scintillating crystal has been produced from archaeological lead for the first time. The advanced technique for deep purification of lead against chemical impurities was used resulting in 99.9995% purity level of final material. The archPbMoO4 crystal was characterized by means of cryogenics bolometric measurements and demonstrates excellent performances as a scintillating bolometer. The energy resolution (0.3% at 1462 keV of 40K), the high light yield (5.2 keV/MeV for γs, and 1.2 keV/MeV for α particles) and the highly efficient particle identification achieved with this detector, representing the high quality of the crystal. As a final proof for the feasibility of the archPbMoO4 crystal as a promising detector to search for the neutrinoless double β-decay of 100Mo, the crystal should be produced using the LTG Czochralski technique to prevent the possible contamination during the crystal growth and to increase the production yield

Final results of the EDELWEISS-II WIMP search using a 4-kg array of cryogenic germanium detectors with interleaved electrodes

The EDELWEISS-II collaboration has completed a direct search for WIMP dark matter with an array of ten 400-g cryogenic germanium detectors in operation at the Laboratoire Souterrain de Modane. The combined use of thermal phonon sensors and charge collection electrodes with an interleaved geometry enables the efficient rejection of gamma-induced radioactivity as well as near-surface interactions. A total effective exposure of 384 kg.d has been achieved, mostly coming from fourteen months of continuous operation. Five nuclear recoil candidates are observed above 20 keV, while the estimated background is 3.0 events. The result is interpreted in terms of limits on the cross-section of spin-independent interactions of WIMPs and nucleons. A cross-section of 4.4x10^-8 pb is excluded at 90%CL for a WIMP mass of 85 GeV. New constraints are also set on models where the WIMP-nucleon scattering is inelastic.Comment: 23 pages, 5 figures; matches published versio

The CUORE cryostat: an infrastructure for rare event searches at millikelvin temperatures

The CUORE experiment is the world's largest bolometric experiment. The detector consists of an array of 988 TeO2 crystals, for a total mass of 742 kg. CUORE is presently taking data at the Laboratori Nazionali del Gran Sasso, Italy, searching for the neutrinoless double beta decay of 130Te. A large custom cryogen-free cryostat allows reaching and maintaining a base temperature of about 10 mK, required for the optimal operation of the detector. This apparatus has been designed in order to achieve a low noise environment, with minimal contribution to the radioactive background for the experiment. In this paper, we present an overview of the CUORE cryostat, together with a description of all its sub-systems, focusing on the solutions identified to satisfy the stringent requirements. We briefly illustrate the various phases of the cryostat commissioning and highlight the relevant steps and milestones achieved each time. Finally, we describe the successful cooldown of CUORE

Double-beta decay of 130^{130}Te to the first 0+^{+} excited state of 130^{130}Xe with CUORICINO

The CUORICINO experiment was an array of 62 TeO$_{2}$ single-crystal bolometers with a total $^{130}$Te mass of $11.3\,$kg. The experiment finished in 2008 after more than 3 years of active operating time. Searches for both $0\nu$ and $2\nu$ double-beta decay to the first excited $0^{+}$ state in $^{130}$Xe were performed by studying different coincidence scenarios. The analysis was based on data representing a total exposure of N($^{130}$Te)$\cdot$t=$9.5\times10^{25}\,$y. No evidence for a signal was found. The resulting lower limits on the half lives are $T^{2\nu}_{1/2}(^{130} Te\rightarrow^{130} Xe^{*})>1.3\times10^{23}\,$y (90% C.L.), and $T^{0\nu}_{1/2}(^{130} Te\rightarrow^{130} Xe^{*})>9.4\times10^{23}\,$y (90% C.L.).Comment: 6 pages, 4 figure

Discovery of the 151^{151}Eu α\alpha decay

We report on the first compelling observation of $\alpha$ decay of $^{151}$Eu to the ground state of $^{147}$Pm. The measurement was performed using a 6.15 g Li$_6$Eu(BO$_3$)$_3$ crystal operated as a scintillating bolometer. The Q-value and half-life measured are: Q = 1948.9$\pm 6.9(stat.) \pm 5.1(syst.)$ keV, and T$_{1/2}=\left( 4.62\pm0.95(stat.)\pm0.68(syst.)\right) \times 10^{18}$ y . The half-life prediction of nuclear theory using the Coulomb and proximity potential model are in good agreement with this experimental result

CUORE and beyond: bolometric techniques to explore inverted neutrino mass hierarchy

The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay of $^{130}$Te. With 741 kg of TeO$_2$ crystals and an excellent energy resolution of 5 keV (0.2%) at the region of interest, CUORE will be one of the most competitive neutrinoless double beta decay experiments on the horizon. With five years of live time, CUORE projected neutrinoless double beta decay half-life sensitivity is $1.6\times 10^{26}$ y at $1\sigma$ ($9.5\times10^{25}$ y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40--100 meV (50--130 meV). Further background rejection with auxiliary light detector can significantly improve the search sensitivity and competitiveness of bolometric detectors to fully explore the inverted neutrino mass hierarchy with $^{130}$Te and possibly other double beta decay candidate nuclei.Comment: Submitted to the Proceedings of TAUP 2013 Conferenc

Validation of techniques to mitigate copper surface contamination in CUORE

In this article we describe the background challenges for the CUORE experiment posed by surface contamination of inert detector materials such as copper, and present three techniques explored to mitigate these backgrounds. Using data from a dedicated test apparatus constructed to validate and compare these techniques we demonstrate that copper surface contamination levels better than 10E-07 - 10E-08 Bq/cm2 are achieved for 238U and 232Th. If these levels are reproduced in the final CUORE apparatus the projected 90% C.L. upper limit on the number of background counts in the region of interest is 0.02-0.03 counts/keV/kg/y depending on the adopted mitigation technique.Comment: 10 pages, 6 figures, 6 table

Exploring the Neutrinoless Double Beta Decay in the Inverted Neutrino Hierarchy with Bolometric Detectors

Neutrinoless double beta decay (0nubb) is one of the most sensitive probes for physics beyond the Standard Model, providing unique information on the nature of neutrinos. In this paper we review the status and outlook for bolometric 0nubb decay searches. We summarize recent advances in background suppression demonstrated using bolometers with simultaneous readout of heat and light signals. We simulate several configurations of a future CUORE-like bolometer array which would utilize these improvements and present the sensitivity reach of a hypothetical next-generation bolometric 0nubb experiment. We demonstrate that a bolometric experiment with the isotope mass of about 1 ton is capable of reaching the sensitivity to the effective Majorana neutrino mass (|mee|) of order 10-20 meV, thus completely exploring the so-called inverted neutrino mass hierarchy region. We highlight the main challenges and identify priorities for an R&D program addressing them.Comment: 22 pages, 15 figures, submitted to EPJ