Preserving privacy against external and internal threats in WSN data aggregation

In this paper, we propose two efficient and privacy-preserving data aggregation protocols for WSNs: PASKOS (Privacy preserving based on Anonymously Shared Keys and Omniscient Sink) and PASKIS (Privacy preserving based on Anonymously Shared Keys and Ignorant Sink)—requiring low overhead. Both protocols guarantee privacy preservation and a high data-loss resilience. In particular, PASKOS effectively protects the privacy of any node against other nodes, by requiring O(log?N) communication cost in the worst case and O(1) on average, and O(1) as for memory and computation. PASKIS can even protect a node’s privacy against a compromised sink, requiring only O(1) overhead as for computation, communication, and memory; however, these gains in efficiency are traded-off with a (slightly) decrease in the assured level of privacy. A thorough analysis and extensive simulations demonstrate the superior performance of our protocols against existing solutions in terms of privacy-preserving effectiveness, efficiency, and accuracy of computed aggregation.     

Bit error outage for diversity reception in shadowing environment

This letter addresses the problem of evaluating the bit error outage (BEO), i.e., the outage probability defined in terms of bit error probability, in a Rayleigh fading and shadowing environment. We consider coherent detection of binary phase-shift keying with maximal ratio combining (MRC). As an example application, the BEO in a log-normal shadowing environment is analyzed and the improvement in terms of BEO due to MRC is quantified in different shadowing environments.     

Optimal capacity of p-persistent CSMA protocols

We deal with the characterization and computation of the p value, say p/sub opt/, corresponding to the maximum protocol capacity in p-persistent carrier-sense multiaccess (CSMA) protocols. The contribution of this paper is twofold. First, we give an analytical justification, and a numerical validation of a heuristic formula widely used in the literature to characterize the p/sub opt/. Second, we provide closed formulas for the p/sub opt/, and we show that the optimal capacity state, given the message length distribution, is characterized by an invariant figure: the Mp/sub opt/ product.     

Physical characterization of deep bulk levels by the MOS conductance technique

The a.c. response of SRH centers in the bulk silicon of an MOS capacitor is reconsidered in the case of traps far from midgap for which the dominant dissipative process is the a.c. delay in capture and emission of majority carriers. Following the Nicollian and Goetzberger's scheme the MOS admittance is calculated in the whole range of biases starting from a model equivalent circuit in which minority carriers are supposed to be disconnected from the bulk. Henceforth the conductance technique can be employed to characterize the deep bulk levels not only in strong inversion, as previously done by others Authors, but also in the depletion-weak inversion mode. This extension is accomplished without the need of extensive numerical computation and makes it possible to obtain from measurements performed at room temperature the physical parameters of the SRH centers, including their energy level and, in principle, their degeneracy factor.Results of measurements performed on 〈1, 0, 0〉-oriented, CZ and FZ grown wafers are presented. Good correlation is obtained between theory and experiment for the trap conductance as a function of frequency at different values of the surface potential. The deduced density of SRH centers and energy level are also confirmed by DLTS and transient current measurements. Finally, evidence is reported for the existence of a two level trap, probably related to oxygen, in commercial CZ wafers.     

Bulk Heterojunction Organic Photovoltaics Based on Carboxylated Polythiophenes and PCBM on Glass and Plastic Substrates

The optoelectronic and photophysical properties of four regioregular poly[3‐(carboxyalkyl)thiophene‐2,5‐diyl] (P3CAT) with different carboxyalkyl chain lengths (propyl to hexyl) are reported. Each P3CAT is combined with [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester to form the photoactive bulk heterojunction layer for organic photovoltaic devices. The extent of hydrogen bonding and polymer crystallinity in the films has been determined through infrared spectroscopy and X‐ray diffraction. The mechanical properties of films are analyzed with nanoindentation, and the measurements suggest that P3CATs are suitable for use in flexible devices. Power conversion efficiencies of up to 2.6% and 1.6% are obtained for devices fabricated in air, and supported on glass and flexible poly(ethylene terephthalate) substrates, respectively.     

5G for the Support of Public Safety Services

Wireless Personal Communications - The Internet of Things (IoT) is the most recent Internet evolution that integrates many smart devices, such as constrained devices, smart tablets, smart vehicles,...     

A natural language model for managing TV-Anytime information in mobile environments

The TV-Anytime standard describes the structures of categories of digital TV program metadata, as well as user profile metadata for TV programs. We describe a natural language (NL) model for the users to interact with the TV-Anytime metadata and preview TV programs from their mobile devices. The language utilises completely the TV-Anytime metadata specifications (upper ontologies), as well as domain-specific ontologies. The interaction model does not use clarification dialogues, but it uses the user profiles as well as TV-Anytime metadata information and ontologies to rank the possible responses in case of ambiguities. We describe implementations of the model that run on a PDA and on a mobile phone, and manage the metadata on a remote TV-Anytime-compatible TV set. We present user evaluations of the approach. Finally, we propose a generalised implementation framework that can be used to easily provide NL interfaces for mobile devices for different applications and ontologies.     

Attention to hierarchical level influences attentional selection of spatial scale.

Ample evidence suggests that global perception may involve low spatial frequency (LSF) processing and that local perception may involve high spatial frequency (HSF) processing (Shulman, Sullivan, Gish, & Sakoda, 1986; Shulman & Wilson, 1987; Robertson, 1996). It is debated whether SF selection is a low-level mechanism associating global and local information with absolute LSF and HSF content, or whether it is a higher level mechanism involving a selective process that defines the SF range in which global and local can then be relatively defined. The present study provides support for the latter claim by demonstrating that allocating attention to global or local levels of hierarchical displays biased selection of LSFs or HSFs, respectively, in subsequently presented compound gratings. This bias occurred despite a change in the response dimension (from letter identification in the hierarchical stimulus to orientation discrimination in the grating) and despite a difference in retinal location of the hierarchical stimuli and the grating stimulus. Moreover, the bias was determined by the relationship between the 2 SFs in the compound grating (i.e., their relative frequency) rather than the absolute SF values. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of a Typical and an Atypical Antipsychotic on the Disruption of Prepulse Inhibition Caused by Corticotropin-Releasing Factor and by Rat Strain.

Male Wistar-Kyoto (WKY) and Brown Norway (BN) rats (11-12 weeks, n = 184) received an injection of saline, haloperidol, or clozapine, followed by an intracerebroventricular infusion of saline or corticotropin-releasing factor (CRF). Rats were tested for prepulse inhibition (PPI) of the acoustic startle response. BN rats showed less PPI than WKY rats, and neither antipsychotic alone enhanced PPI. In WKY rats, both haloperidol and clozapine attenuated the CRF-induced decrease in PPI. In CRF-treated BN rats, clozapine-enhanced PPI. A clozapine-induced decrease in startle amplitude was seen in CRF-treated BN rats but not in CRF-treated WKY rats. Although the disruption of PPI caused by exogenous CRF administration can be reversed by acute antipsychotic treatment, baseline PPI is not altered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)