Secrecy Performance of Cooperative Cognitive AF Relaying Networks With Direct Links Over Mixed Rayleigh and Double-Rayleigh Fading Channels

This paper investigates the secrecy performance of an underlay cooperative cognitive relaying network, wherein a secondary source vehicle communicates with a fixed secondary destination terminal via a direct link and with the assistance of a secondary amplify-and-forward relay vehicle in the presence of a passive secondary eavesdropper vehicle, taking into consideration of interference at the primary user. We assume that the eavesdropper vehicle takes the advantages of both the relay link and direct link. We consider that vehicle-to-vehicle links are modeled as double-Rayleigh fading, while vehicle-to-fixed infrastructure links are modeled as Rayleigh fading. Such a scenario finds it relevancy in vehicle-to-vehicle communication and/or vehicle-to-infrastructure communication under spectrum sharing heterogeneous cooperative vehicular networks. For such a realistic scenario, in particular, we derive a tight lower bound expression of the secrecy outage probability under mixed Rayleigh and double-Rayleigh fading channels. We also present an effective secrecy diversity order analysis and show that the considered system can achieve a secrecy diversity order of 2 for infinitely large average channel gain values of the main links. Finally, we demonstrate the accuracy of our analytical findings via numerical and simulation results and show the impact of channel conditions, primary interference constraints, and direct links on the secrecy performance of the considered syste

Healthcare Access and Quality Index based on mortality from causes amenable to personal health care in 195 countries and territories, 1990-2015 : a novel analysis from the Global Burden of Disease Study 2015

Background National levels of personal health-care access and quality can be approximated by measuring mortality rates from causes that should not be fatal in the presence of effective medical care (ie, amenable mortality). Previous analyses of mortality amenable to health care only focused on high-income countries and faced several methodological challenges. In the present analysis, we use the highly standardised cause of death and risk factor estimates generated through the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) to improve and expand the quantification of personal health-care access and quality for 195 countries and territories from 1990 to 2015. Methods We mapped the most widely used list of causes amenable to personal health care developed by Nolte and McKee to 32 GBD causes. We accounted for variations in cause of death certification and misclassifications through the extensive data standardisation processes and redistribution algorithms developed for GBD. To isolate the effects of personal health-care access and quality, we risk-standardised cause-specific mortality rates for each geography-year by removing the joint effects of local environmental and behavioural risks, and adding back the global levels of risk exposure as estimated for GBD 2015. We employed principal component analysis to create a single, interpretable summary measure-the Healthcare Quality and Access (HAQ) Index-on a scale of 0 to 100. The HAQ Index showed strong convergence validity as compared with other health-system indicators, including health expenditure per capita (r= 0.88), an index of 11 universal health coverage interventions (r= 0.83), and human resources for health per 1000 (r= 0.77). We used free disposal hull analysis with bootstrapping to produce a frontier based on the relationship between the HAQ Index and the Socio-demographic Index (SDI), a measure of overall development consisting of income per capita, average years of education, and total fertility rates. This frontier allowed us to better quantify the maximum levels of personal health-care access and quality achieved across the development spectrum, and pinpoint geographies where gaps between observed and potential levels have narrowed or widened over time. Findings Between 1990 and 2015, nearly all countries and territories saw their HAQ Index values improve; nonetheless, the difference between the highest and lowest observed HAQ Index was larger in 2015 than in 1990, ranging from 28.6 to 94.6. Of 195 geographies, 167 had statistically significant increases in HAQ Index levels since 1990, with South Korea, Turkey, Peru, China, and the Maldives recording among the largest gains by 2015. Performance on the HAQ Index and individual causes showed distinct patterns by region and level of development, yet substantial heterogeneities emerged for several causes, including cancers in highest-SDI countries; chronic kidney disease, diabetes, diarrhoeal diseases, and lower respiratory infections among middle-SDI countries; and measles and tetanus among lowest-SDI countries. While the global HAQ Index average rose from 40.7 (95% uncertainty interval, 39.0-42.8) in 1990 to 53.7 (52.2-55.4) in 2015, far less progress occurred in narrowing the gap between observed HAQ Index values and maximum levels achieved; at the global level, the difference between the observed and frontier HAQ Index only decreased from 21.2 in 1990 to 20.1 in 2015. If every country and territory had achieved the highest observed HAQ Index by their corresponding level of SDI, the global average would have been 73.8 in 2015. Several countries, particularly in eastern and western sub-Saharan Africa, reached HAQ Index values similar to or beyond their development levels, whereas others, namely in southern sub-Saharan Africa, the Middle East, and south Asia, lagged behind what geographies of similar development attained between 1990 and 2015. Interpretation This novel extension of the GBD Study shows the untapped potential for personal health-care access and quality improvement across the development spectrum. Amid substantive advances in personal health care at the national level, heterogeneous patterns for individual causes in given countries or territories suggest that few places have consistently achieved optimal health-care access and quality across health-system functions and therapeutic areas. This is especially evident in middle-SDI countries, many of which have recently undergone or are currently experiencing epidemiological transitions. The HAQ Index, if paired with other measures of health-systemcharacteristics such as intervention coverage, could provide a robust avenue for tracking progress on universal health coverage and identifying local priorities for strengthening personal health-care quality and access throughout the world. Copyright (C) The Author(s). Published by Elsevier Ltd.Peer reviewe

On the secrecy performance of RIS-enabled wireless communications over Nakagami-m fading channels

This paper examines the secrecy performance of reconfigurable intelligent surface aided wireless communication systems. Specifically, we derive the secrecy outage probability (SOP), intercept probability, probability of non-zero secrecy capacity, and ergodic secrecy capacity (ESC) expressions over Nakagami-m fading channels. We further evaluate the asymptotic SOP expressions to get some insights into the secrecy diversity order under two scenarios of interest; (1) when the signal-to-noise ratio approaches infinity, and (2) when the main-to-eavesdropper ratio tends to infinity. Also, we analytically show the effect of reflecting element density on the ESC performance. The numerical and simulation studies verify our analytical findings

Electron Beam Processing of SensorsRelevant Vacoflux-49 Alloy: Experimental Studies of Thermal Zones and Microstructure

Vacoflux-49 (Fe-49% Co-49% V-2%) is used in torque, sonar and gyroscopic sensors applications due to excellent magnetic properties (high saturation magnetisation, low coercivity and high Curie temperature). In this study, the shape, size and characteristics of different thermal zones and the microstructural evolution during electron beam melting and welding of Vacoflux-49 material are studied. The experimental studies on melting have been carried out with under-focussed, focussed and over focussed electron beam. In the case of the under-focussed and over-focused beam, no evaporated zone is found. In the case of focussed beam, a shallow conical-shaped evaporated zone, a choked funnel-shaped fusion zone, a conical shaped partially melted zone and the heat-affected zone are observed. The solidified melt pool in terms of shape, size and microstructure of different zones are investigated for the focussed beam. The grains in the fusion zone appear wavy having crest and trough. The fusion zone microstructure also shows the formation of solidification rings. From the electron beam welding experiments performed for joining two Vacoflux-49 plates (continuous welding), it is found that the weldment shape is similar to the spot melting and re-solidification experiments. The grain growth in different zones in the welding sample is also examined

Secure cognitive radio-enabled vehicular communications under spectrum-sharing constraints

Vehicular communication has been envisioned to support a myriad of essential fifth-generation and beyond use-cases. However, the increasing proliferation of smart and intelligent vehicles has generated a lot of design and infrastructure challenges. Of particular interest are the problems of spectrum scarcity and communication security. Consequently, we considered a cognitive radio-enabled vehicular network framework for accessing additional radio spectrum and exploit physical layer security for secure communications. In particular, we investigated the secrecy performance of a cognitive radio vehicular network, where all the nodes in the network are moving vehicles and the channels between them are modeled as double-Rayleigh fading. Furthermore, adopting an underlay approach, the communication between secondary nodes can be performed by employing two interference constraint strategies at the primary receiver; (1) Strategy I: the secondary transmitter power is constrained by the interference threshold of the primary receiver, and (2) Strategy II: the secondary transmitter power is constrained by both the interference threshold of the primary receiver and the maximum transmit power of the secondary network. Under the considered strategies, we derive the exact secrecy outage probability (SOP) and ergodic secrecy capacity (ESC) expressions over double-Rayleigh fading. Moreover, by analyzing the asymptotic SOP behavior, we show that a full secrecy diversity of 1 can be achieved, when the average channel gain of the main link goes to infinity with a fixed average wiretap channel gain. From the ESC analysis, it is revealed that the ESC follows a scaling law of ΘlnΩm2Ωe2 for large Ωm and Ωe, where Ωm and Ωe are the average channel gains of the main link and wiretap link. The numerical and simulation results verify our analytical findings.publishe

Evaluation of flow resistance equations for high gradient rivers using geometric standard deviation of bed material

A dataset of 2184 field measurements reported in the literature was used to evaluate the predictive capability of eight conventional flow resistance equations to predict the mean flow velocity in gravel-bed rivers. The results reveal considerable disagreement with the observed flow velocities for relative submergence less than 4 and for the non-uniformity of the bed material greater than 7.5 for all the equations. However, the predictions made using the Smart and Jäggi, 1983, Ferguson, 2007, and Rickenmann and Recking (2011) equations were closer to the observed values. Furthermore, bedload sediment transport also reduces the predictive capability of the equations considered in this study except for the Recking et al. (2008) equation, which was developed considering active bedload transport. The performance of flow resistance equations improves when corrected by considering the geometric standard deviation of the bed material. Here we present an empirical approach using the whole dataset and its subsets for accounting for the additional energy losses occurring due to the wake vortices, spill losses, and free surface instabilities occurring due to the protrusions from the bed. The results obtained using the validation dataset shows the importance and usefulness of this approach to account for the additional energy losses, especially for the Strickler, 1923, Keulegan, 1938 equations

Investigation of deformation behaviour of steel, aluminium and copper alloys during hydro-mechanical drawing

The hydro-mechanical drawing combines conventional deep drawing and sheet hydroforming and is widely used in the automotive industry. In this study, we designed and fabricated an indigenous experimental set-up that is low cost, low weight and portable. This study investigated the deformation of sheet metals into hemispherical cup-shaped parts made of different materials, viz., aluminium 8011 alloys, copper C12200 and steel EN10130 alloys. The initial thickness of sheet metal was 0.4 mm, the most common thickness range used in automotive applications. The deformation behaviour in terms of dome height has been measured by varying the pressure of the fluids. Aluminium 8011 alloy sheets showed a maximum dome height of 11.46 mm at a pressure of 1.47 MPa with no rupture. Steel EN10130 sheets had a maximum dome height of 10.89 mm at a pressure of 9.31 MPa. It was concluded that the behaviours of materials are different in the hydro-mechanical drawing process than in mechanical tests. Copper C12200 sheet showed superior formability with a maximum dome height of 18.91 mm at a pressure of 7.06 MPa than other materials without fracture

Eksperimentalna raziskava in matematični model toplotne prehodnosti dvokapnega solarnega destilatorja

n this study, a double slope solar still has been designed and fabricated with the help of locally available materials for the climatic condition of Sultanpur, India. The experimental study was performed to investigate the effect of basin water, wind velocity on the heat transfer coefficient (convective, evaporative, and radiative) and yield of solar still. A mathematical model is developed to understand the impact of wind velocity and basin water depth in the double slope solar still on the heat transfer coefficient. It was found that the convective heat transfer coefficient depends upon the water mass and the temperature of basin mass, and glass cover temperature. The maximum value of hew (55.05 W/(m2K) and 31.80 W/(m2K)) and hcw , (2.48 W/(m2K) and 2.38 W/(m2K)) found for depths of 2 cm and 5 cm, respectively. The radiative heat transfer coefficient found to be a maximum of 8.31 W/(m2K) for 2 cm depth, and it increases as the condensation increases, because the glass surface temperature increases as vapour transfers its energy to the surface. On increasing the depth from 2 cm to 5 cm, the yield from the solar still decreases by 25.45 %. The maximum yield of 2.5 l/m2/day was found for a 2 cm water depth. The theoretical and experimental yield agreed with an error of 7.5 %, 3.25 %, 7.4 %, and 8.4 % for water depths of 2 cm, 3 cm, 4 cm, and 5 cm, respectively. It was also found that the yield from the solar still increases as the wind speed increase because this leads the faster condensation at the glass surface

Elicitation of native bio protective microbial agents associated systemic defense responses and plant growth promotion against bacterial stalk rot pathogen in sorghum (Sorghum bicolor)

Abstract Dickeya dadantii is the causal agent of bacterial stalk rot and one of the most destructive and widespread diseases of the sorghum in the world. Here, we explored microbe-based approaches for managing this destructive pathogen, intending to provide alternatives for integrated disease management. The objective of the research was to decipher the effect of antagonistic microbes on systemic defense enzymes, histochemical changes, plant growth attributes, reduction in disease severity, and interaction of these antagonistic microbes with host. Trichoderma, Pseudomonas, and Bacillus isolates were collected from rhizospheric soil and characterized using morphological and molecular tools. ITS and 16S rRNA sequences were analyzed to determine the molecular characterization of all antagonist microbes, and they were identified as T. asperellum, T. viride, T. harzianum, B. subtilis, and P. flourescens. These isolates were evaluated for antibacterial properties against D. dadantii under in vitro conditions and showed the higher inhibition in a dual culture method. Further, the effects of seed bio-priming and soil application of these isolates were tested under glasshouse and field conditions. T. viride outperformed the other isolates, significantly enhancing the plant growth parameters and induced resistance to Dickeya dadantii (BSR). T. viride showed a significantly higher accumulation of defensive enzymes, viz. PAL (1.02), PO (1.70), PPO (1.25), CAT (1.11), and TPC (0.91) at 48 h after pathogen challenge, as compared to the control. Histochemical tests confirmed lignification and callose deposition in the cell walls of the treated plants. Antagonist microbes were further evaluated under field conditions against D. dadantii infection. Compared to the control, there is a significant enhancement of plant growth parameters and yield with a simultaneous decrease in disease severity in T. viride treated plants. Results showed that the potential benefits of T. viride could not only effectively induce resistance in plants, enhance plant growth, increase yield, and suppress pathogen infection but also reduce the use of hazardous pesticides. As a result of correlation, PCA and heat map analyses indicated that T. viride is interconnected to determine the crop ability to sustain its growth under pathogen stress