Packet Size Optimization for Cognitive Radio Sensor Networks Aided Internet of Things

Cognitive Radio Sensor Networks (CRSN) is state of the art communication paradigm for power constrained short range data communication. It is one of the potential technology adopted for Internet of Things (IoT) and other futuristic Machine to Machine (M2M) based applications. Many of these applications are power constrained and delay sensitive. Therefore, CRSN architecture must be coupled with different adaptive and robust communication schemes to take care of the delay and energy-efficiency at the same time. Considering the tradeoff that exists in terms of energy efficiency and overhead delay for a given data packet length, it is proposed to transmit the physical layer payload with an optimal packet size (OPS) depending on the network condition. Furthermore, due to the cognitive feature of CRSN architecture overhead energy consumption due to channel sensing and channel handoff plays a critical role. Based on the above premises, in this paper we propose a heuristic exhaustive search based Algorithm-1 and a computationally efficient suboptimal low complexity Karuh-Kuhn- Tucker (KKT) condition based Algorithm-2 to determine the optimal packet size in CRSN architecture using variable rate m-QAM modulation. The proposed algorithms are implemented along with two main cognitive radio assisted channel access strategies based on Distributed Time Slotted-Cognitive Medium Access Control (DTS-CMAC) and Centralized Common Control Channel based Cognitive Medium Access Control (CC-CMAC) and their performances are compared. The simulation results reveals that proposed Algorithm-2 outperforms Algorithm-1 by a significant margin in terms of its implementation time. For the exhaustive search based Algorithm-1 the average time consumed to determine OPS for a given number of cognitive users is 1.2 seconds while for KKT based Algorithm-2 it is of the order of 5 to 10 ms. CC-CMAC with OPS is most efficient in terms of overall energy consumption but incurs more delay as compared to DTS-CMAC with OPS scheme

Packet Size Optimization for Multiple Input Multiple Output Cognitive Radio Sensor Networks aided Internet of Things

The determination of Optimal Packet Size (OPS) for Cognitive Radio assisted Sensor Networks (CRSNs) architecture is non-trivial. State of the art in this area describes various complex techniques to determine OPS for CRSNs. However, it is observed that under high interference from the surrounding users, it is not possible to determine a feasible optimal packet size of data transmission under the simple point-to-point CRSN network topology. This is contributed primarily due to the peak transmit power constraint of the cognitive nodes. To address this specific challenge, this paper proposes a Multiple Input Multiple Output based Cognitive Radio Sensor Networks (MIMO-CRSNs) architecture for futuristic technologies like Internet of Things (IoT) and machine-to-machine (M2M) communications. A joint optimization problem is formulated taking into account network constraints like the overall end to end latency, interference duration caused to the non-cognitive users, average BER and transmit power.We propose our Algorithm-1 based on generic exhaustive search technique blue to solve the optimization problem. Furthermore, a low complexity suboptimal Algorithm-2 based on solving classical Karush-Kuhn-Tucker (KKT) conditions is proposed. These algorithms for MIMO-CRSNs are implemented in conjunction with two different channel access schemes. These channel access schemes are Time Slotted Distributed Cognitive Medium Access Control denoted as MIMO-DTS-CMAC and CSMA/CA assisted Centralized Common Control Channel based Cognitive Medium Access Control denoted as MIMO-CC-CMAC. Simulations reveal that the proposed MIMO based CRSN network outperforms the conventional point-to-point CRSN network in terms of overall energy consumption. Moreover, the proposed Algorithm-1 and Algorithm2 shows perfect match and the implementation complexity of Algorithm-2 is much lesser than Algorithm-1. Algorithm-1 takes almost 680 ms to execute and provides OPS value for a given number of users while Algorithm- 2 takes 4 to 5 ms on an average to find the optimal packet size for the proposed MIMO-CRSN framework

Three precise gamma-ray burst source locations

The precise source regions of three moderately intense gamma ray bursts are derived. These events were observed with the first interplanetary burst sensor network. The optimum locations of the detectors, widely separated throughout the inner solar system, allowed for high accuracy, over-determined source fields of size 0.7 to 7.0 arc-min(2). All three locations are at fairly high galactic latitude in regions of low source confusion; none can be identified with a steady source object. Archived photographs were searched for optical transients that are able to be associated with these source fields; one such association was made

Adsorption of Oxygen Molecules on Individual Carbon Single-walled Nanotubes

Our study of the adsorption of oxygen molecules on individual semiconductiong single-walled carbon nanotubes at ambient conditions reveals that the adsorption is physisorption, that the resistance without O2 increases by ~two orders of magnitude as compared to that with O2, and that the sensitive response is due to the pinning of the Fermi level near the top of the valence band of the tube resulting from impurity states of O2 appearing above the valence band.Comment: 16 pages, 4 figure

Fermion masses and mixings in gauge theories

The recent evidence for neutrino oscillations stimulate us to discuss again the problem of fermion masses and mixings in gauge theories. In the standard model, several forms for quark mass matrices are equivalent. They become ansatze within most extensions of the standard model, where also relations between quark and lepton sectors may hold. In a seesaw framework, these relations can constrain the scale of heavy neutrino mass, which is often related to the scale of intermediate or unification gauge symmetry. As a consequence, two main scenarios arise. Hierarchies of masses and mixings may be explained by broken horizontal symmetries.Comment: 25 pages, RevTex, no figures. Few misprints corrected and two references adde

Spitzer IRS Spectra of Optically Faint Infrared Sources with Weak Spectral Features

Spectra have been obtained with the low-resolution modules of the Infrared Spectrograph (IRS) on the Spitzer Space Telescope (Spitzer) for 58 sources having f$_{\nu}$(24 micron) > 0.75 mJy. Sources were chosen from a survey of 8.2 deg$^{2}$ within the NOAO Deep Wide-Field Survey region in Bootes (NDWFS) using the Multiband Imaging Photometer (MIPS) on the Spitzer Space Telescope. Most sources are optically very faint (I > 24mag). Redshifts have previously been determined for 34 sources, based primarily on the presence of a deep 9.7 micron silicate absorption feature, with a median z of 2.2. Spectra are presented for the remaining 24 sources for which we were previously unable to determine a confident redshift because the IRS spectra show no strong features. Optical photometry from the NDWFS and infrared photometry with MIPS and the Infrared Array Camera on the Spitzer Space Telescope (IRAC) are given, with K photometry from the Keck I telescope for some objects. The sources without strong spectral features have overall spectral energy distributions (SEDs) and distributions among optical and infrared fluxes which are similar to those for the sources with strong absorption features. Nine of the 24 sources are found to have feasible redshift determinations based on fits of a weak silicate absorption feature. Results confirm that the "1 mJy" population of 24 micron Spitzer sources which are optically faint is dominated by dusty sources with spectroscopic indicators of an obscured AGN rather than a starburst. There remain 14 of the 58 sources observed in Bootes for which no redshift could be estimated, and 5 of these sources are invisible at all optical wavelengths.Comment: Accepted by Ap

Attitude towards and factors affecting uptake of population based BRCA testing in the Ashkenazi Jewish population: a cohort study

Objective To evaluate factors affecting unselected‐population‐based‐BRCA‐testing in Ashkenazi‐Jews (AJ). Design Cohort‐study set within recruitment to the GCaPPS‐trial (ISRCTN73338115). Setting North‐London AJ‐population. Population or Sample AJ women/men >18‐years, recruited through self‐referral. Methods AJ‐women/men underwent pre‐test counselling for BRCA‐testing through recruitment clinics (clusters). Consenting individuals provided blood‐sample for BRCA‐testing. Socio‐demographic/family‐history/knowledge/psychological well‐being data along‐with benefits/risks/cultural‐influences (18‐item‐questionnaire measuring ‘attitude’) were collected. 4‐item likert‐scales analysed initial ‘interest’ and ‘intention‐to‐test’ pre‐counselling. Uni‐&‐multivariable logistic‐regression‐models evaluated factors affecting uptake/interest/intention‐to undergo BRCA‐testing. Statistical inference was based on cluster robust standard‐errors and joint Wald‐tests for significance. Item‐Response‐Theory and graded‐response‐models modelled responses to 18‐item questionnaire. Main Outcome Measures Interest, intention, uptake, attitude towards BRCA‐testing. Results 935 (women=67%/men=33%; mean‐age=53.8(S.D=15.02) years) individuals underwent pre‐test genetic‐counselling. Pre‐counselling 96% expressed interest but 60% indicated clear intention‐to undergo BRCA‐testing. Subsequently 88% opted for BRCA‐testing. BRCA‐related knowledge (p=0.013) and degree‐level education(p=0.01) were positively and negatively (respectively) associated with intention‐to‐test. Being married/cohabiting had four‐fold higher‐odds for BRCA‐testing uptake (p=0.009). Perceived benefits were associated with higher pre‐counselling odds for interest and intention‐to undergo BRCA‐testing. Reduced uncertainty/reassurance were the most important factors contributing to decision‐making. Increased importance/concern towards risks/limitations (confidentiality/insurance/emotional‐impact/inability to prevent cancer/marriage‐ability/ethnic‐focus/stigmatization) were significantly associated with lower‐odds of uptake‐of BRCA‐testing, and discriminated between acceptors and decliners. Male‐gender/degree‐level‐education (p=0.001) had weaker, while having children had stronger (p=0.005) attitudes towards BRCA‐testing. Conclusions BRCA‐testing in the AJ‐population has high acceptability. Pre‐test counselling increases awareness of disadvantages/limitations of BRCA‐testing, influencing final cost‐benefit perception and decision‐making on undergoing testing. This article is protected by copyright. All rights reserved

FPGA-Based Portable Ultrasound Scanning System with Automatic Kidney Detection

Bedsides diagnosis using portable ultrasound scanning (PUS) offering comfortable diagnosis with various clinical advantages, in general, ultrasound scanners suffer from a poor signal-to-noise ratio, and physicians who operate the device at point-of-care may not be adequately trained to perform high level diagnosis. Such scenarios can be eradicated by incorporating ambient intelligence in PUS. In this paper, we propose an architecture for a PUS system, whose abilities include automated kidney detection in real time. Automated kidney detection is performed by training the Viola–Jones algorithm with a good set of kidney data consisting of diversified shapes and sizes. It is observed that the kidney detection algorithm delivers very good performance in terms of detection accuracy. The proposed PUS with kidney detection algorithm is implemented on a single Xilinx Kintex-7 FPGA, integrated with a Raspberry Pi ARM processor running at 900 MHz

Randomised trial of population-based BRCA testing in Ashkenazi Jews: long-term outcomes

© 2019 Royal College of Obstetricians and Gynaecologists Objective: Unselected population-based BRCA testing provides the opportunity to apply genomics on a population-scale to maximise primary prevention for breast-and-ovarian cancer. We compare long-term outcomes of population-based and family-history (FH)/clinical-criteria-based BRCA testing on psychological health and quality of life. Design: Randomised controlled trial (RCT) (ISRCTN73338115) GCaPPS, with two-arms: (i) population-screening (PS); (ii) FH/clinical-criteria-based testing. Setting: North London Ashkenazi-Jewish (AJ) population. Population/Sample: AJ women/men. Methods: Population-based RCT (1:1). Participants were recruited through self-referral, following pre-test genetic counselling from the North London AJ population. Inclusion criteria: AJ women/men >18 years old; exclusion-criteria: prior BRCA testing or first-degree relatives of BRCA-carriers. Interventions: Genetic testing for three Jewish BRCA founder-mutations: 185delAG (c.68_69delAG), 5382insC (c.5266dupC) and 6174delT (c.5946delT), for (i) all participants in PS arm; (ii) those fulfilling FH/clinical criteria in FH arm. Linear mixed models and appropriate contrast tests were used to analyse the impact of BRCA testing on psychological and quality-of-life outcomes over 3 years. Main outcome measures: Validated questionnaires (HADS/MICRA/HAI/SF12) used to analyse psychological wellbeing/quality-of-life outcomes at baseline/1-year/2-year/3-year follow up. Results: In all, 1034 individuals (691 women, 343 men) were randomised to PS (n = 530) or FH (n = 504) arms. There was a statistically significant decrease in anxiety (P = 0.046) and total anxiety-&-depression scores (P = 0.0.012) in the PS arm compared with the FH arm over 3 years. No significant difference was observed between the FH and PS arms for depression, health-anxiety, distress, uncertainty, quality-of-life or experience scores associated with BRCA testing. Contrast tests showed a decrease in anxiety (P = 0.018), health-anxiety (P < 0.0005) and quality-of-life (P = 0.004) scores in both PS and FH groups over time. Eighteen of 30 (60%) BRCA carriers identified did not fulfil clinical criteria for BRCA testing. Total BRCA prevalence was 2.9% (95% CI 1.97–4.12%), BRCA1 prevalence was 1.55% (95% CI 0.89–2.5%) and BRCA2 prevalence was 1.35% (95% CI 0.74–2.26%). Conclusion: Population-based AJ BRCA testing does not adversely affect long-term psychological wellbeing or quality-of-life, decreases anxiety and could identify up to 150% additional BRCA carriers. Tweetable abstract: Population BRCA testing in Ashkenazi Jews reduces anxiety and does not adversely affect psychological health or quality of life