Collaborative Sensing and Communication Schemes for Cooperative Wireless Sensor Networks

Energy conservation is considered to be one of the key design challenges within resource constrained wireless sensor networks (WSNs) that leads the researchers to investigate energy efficient protocols with some application specific challenges. Dynamic clustering scheme within the deployed sensor nodes is generally considered as one of the energy conservation techniques. However, unbalanced distribution of cluster heads, highly variable number of sensor nodes in the clusters and high number of sensor nodes involved in event reporting tend to drain out the network energy quickly, resulting in unplanned decrease in network lifetime. Performing power aware signal processing, defining communication methods that can provide progressive accuracy and, optimising processing and communication for signal transmission are the challenging tasks. In this thesis, energy efficient solutions are proposed for collaborative sensing and cooperative communication within resource constrained WSNs. A dynamic and cooperative clustering as well as neighbourhood formation scheme is proposed that is expected to evenly distribute the energy demand from the cluster heads and optimise the number of sensor nodes involved in event reporting. The distributive and dynamic behaviour of the proposed framework provides an energy efficient self-organising solution for WSNs that results in an improved network lifetime. The proposed framework is independent of the nature of the sensing type to support applications that require either time-driven sensing, event-driven sensing or hybrid of both sensing types. A cooperative resource selection and transmission scheme is also proposed to improve the performance of collaborative WSNs in terms of maintaining link reliability. As a part of the proposed cooperative nature of transmission, the transmitreceive antennae selection scheme and lattice reduction algorithm have also been considered. It is assumed that the channel state information is estimated at the ii receiver and there is a feedback link between the wireless sensing nodes and the fusion centre receiver. For the ease of system design engineer to achieve a predefined capacity or quality of service, a set of analytical frameworks that provide tighter error performance lower bound for zero forcing (ZF), minimum mean square error (MMSE) and maximum likelihood (ML) detection schemes are also presented. The dynamic behaviour has been adopted within the framework with a proposed index derived from the received measure of the channel quality, which has been attained through the feedback channel from the fusion centre. The dynamic property of the proposed framework makes it robust against time-varying behaviour of the propagation environment. Finally, a unified framework of collaborative sensing and communication schemes for cooperative WSNs is proposed to provide energy efficient solutions within resource constrained environments. The proposed unified framework is fully decentralised which reduces the amount of information required to be broadcasted. Such distributive capability accelerates the decision-making process and enhances the energy conservation. Furthermore, it is validated by simulation results that the proposed unified framework provides a trade-off between network lifetime and transmission reliability while maintaining required quality of service

NOMA based resource allocation and mobility enhancement framework for IoT in next generation cellular networks

With the unprecedented technological advances witnessed in the last two decades, more devices are connected to the internet, forming what is called internet of things (IoT). IoT devices with heterogeneous characteristics and quality of experience (QoE) requirements may engage in dynamic spectrum market due to scarcity of radio resources. We propose a framework to efficiently quantify and supply radio resources to the IoT devices by developing intelligent systems. The primary goal of the paper is to study the characteristics of the next generation of cellular networks with non-orthogonal multiple access (NOMA) to enable connectivity to clustered IoT devices. First, we demonstrate how the distribution and QoE requirements of IoT devices impact the required number of radio resources in real time. Second, we prove that using an extended auction algorithm by implementing a series of complementary functions, enhance the radio resource utilization efficiency. The results show substantial reduction in the number of sub-carriers required when compared to conventional orthogonal multiple access (OMA) and the intelligent clustering is scalable and adaptable to the cellular environment. Ability to move spectrum usages from one cluster to other clusters after borrowing when a cluster has less user or move out of the boundary is another soft feature that contributes to the reported radio resource utilization efficiency. Moreover, the proposed framework provides IoT service providers cost estimation to control their spectrum acquisition to achieve required quality of service (QoS) with guaranteed bit rate (GBR) and non-guaranteed bit rate (Non-GBR)

Risk assessment through evaluation of potentially toxic metals in the surface soils of the Qassim area, Central Saudi Arabia

© Società Geologica Italiana, Roma 2016. Metal pollution is an increasing environmental problem worldwide, especially in regions undergoing rapid development. The present work highlights the extent of metal pollution in the central part of Saudi Arabia, which is currently experiencing significant agricultural development. The study determined concentrations of Hg, Cd, Zn, As, Mo, Cu, Pb and Cr in surface soils, assessing the level of pollution and potential ecological risks using soil quality guidelines, the geo-accumulation index (Igeo), the Hakanson potential ecological risk index (RI) and standard statistical analysis methods. Overall, the mean potential ecological risk values of metals in the surveyed soils display the following decreasing trend: H

AlGaInAs/InP Based Five & Three Quantum Wells Mode Locked Laser Diodes: A Comparative Study

Comparison of performance of semiconductor mode-locked laser diodes fabricated using AlGaInAs/InP material containing 5 and 3 quantum wells (QWs) inside the active region is reported. The simulations and experimental results show that lasers containing five QWs materials produce larger beam divergence and temporally broader optical pulses. For improvement in the mode-locking of lasers and reducing the far-field pattern, the number of QWs inside the active region was decreased from five to three and a far-field decreasing layer along with a thick spacer layer were introduced in the n-cladding region of epitaxial material. Before growing the material, simulations were carried out to optimise the design. The lower optical confinement factor and higher gain saturation energy of three QWs based mode-locked lasers provide higher average and peak output power, reduced and symmetric far-field pattern, better radio frequency (RF) spectra, shorter optical pulses, and stable optimal mode-locking for a wide range of gain current and saturable absorber reverse voltage

Uncertainty-aware RAN Slicing via Machine Learning Predictions in Next-Generation Networks

Network slicing enables 5G network operators to offer diverse services in the form of end-to-end isolated slices, over shared physical infrastructure. Wireless service providers are facing the need to plan and rapidly evolve their slices configuration to meet the varied tenants’ demand. Network slicing unfolds a new market dimension to the infrastructure providers as well as to the tenants, who may acquire a network slice from the infrastructure provider to deliver a specific service to their respective subscribers. In this new context, there is a growing need for new network resource allocation algorithms to capture such proposition. This paper addresses this problem by introducing a family of online algorithms with the aim to (i) minimize tenants spectrum allocation costs, (ii) maximize radio resource utilization and (iii) ensure that the service level agreements (SLAs) provided to tenants are satisfied. We focus on improving the performance of prediction-based decisions that are made by a tenant when prediction models lack the desired accuracy. Our evaluations show that the proposed probabilistic approach can automatically adapt to prediction error variance, while largely improving network slice acquisition cost and resource utilization

Mobility Support for MIMO-NOMA User Clustering in Next-Generation Wireless Networks

Non-Orthogonal Multiple Access (NOMA) is a promising technology for future-generation wireless systems, with potential to contribute to the improvement of spectral efficiency. NOMA groups users into clusters, based on channel gain-difference. However, user mobility continuously changes the channel gain, which often requires re-clustering. In this paper, we study a set of re-clustering methods: arbitrary, one-by-one and Kuhn-Munkres assignment algorithm (KMAA), that expedite link re-establishment and keep the clusters interference-free, taking into account the mobility of users. The methods are applied to automatically dissociate identified users within clusters, when the gain-difference is lower than a given threshold, followed by re-association procedure, which integrates users into different clusters, maintaining an appropriate gain-difference. Experimental results show that the KMAA method improves efficiency and capacity through minimizing the number of re-clustering events, improving resource utilization, and lowering signaling overhead. Other sets of results highlight the throughput and outage probability gains of the KMAA method across a wide range of mobility scenarios. We also provide an analysis of the KMAA algorithm when applied to MIMO-NOMA, encompassing link resiliency and maintenance of average gain-difference, among users in clusters

Response of Some Biochemical Components in Phosphine Susceptible and Resistant Populations of 4th Instar Larvae of Trogoderma Granarium (Coleoptera: Dermestidae)

Stored grain pests are controlled by a number different pesticides and fumigants. This study, investigated the effect of phosphine on khapra beetle (Trogoderma granarium) which is a notorious pest in stored grain godowns in Pakistan and a significant trade pest around the world. For this purpose, the LC50 of phosphine against 4th instar larvae of two different strains of T. granarium (collected from different cities of Punjab, Khaniwal (Khw) and Chishtian (Chi) were determined. The LC50 values shown by these strains were 3.8 and 7.0 ppm respectively. On the basis of LC50 the Chishtian strain was considered as resistant to phosphine, whereas Khaniwal strain was regarded as a susceptible strain. The effect of sub lethal doses (LC10, LC20, and LC30) on the larval stages of two T. granarium strains were evaluated. The toxic effect of phosphine was observed on glucose, glycogen, total lipid, FAA, protein and trehalose of the strains after 24 hours of exposure. The treatment showed significant increase in glucose content in Khaniwal (susceptible) and decrease in resistant strains throughout the treatment. Lipid content showed a highly significant increase for all doses of phosphine in both strains. Glycogen, Trehalose, protein and FAA contents depicted highly significantly increases in the resistant strain at LC10, LC20, and LC30

Initial-Dip Existence and Estimation in Relation to DPF and Data Drift

Early de-oxygenation (initial dip) is an indicator of the primal cortical activity source in functional neuro-imaging. In this study, initial dip's existence and its estimation in relation to the differential pathlength factor (DPF) and data drift were investigated in detail. An efficient algorithm for estimation of drift in fNIRS data is proposed. The results favor the shifting of the fNIRS signal to a transformed coordinate system to infer correct information. Additionally, in this study, the effect of the DPF on initial dip was comprehensively analyzed. Four different cases of initial dip existence were treated, and the resultant characteristics of the hemodynamic response function (HRF) for DPF variation corresponding to particular near-infrared (NIR) wavelengths were summarized. A unique neuro-activation model and its iterative optimization solution that can estimate drift in fNIRS data and determine the best possible fit of HRF with free parameters were developed and herein proposed. The results were verified on simulated data sets. The algorithm is applied to free available datasets in addition to six healthy subjects those were experimented using fNIRS and observations and analysis regarding shape of HRF were summarized as well. A comparison with standard GLM is also discussed and effects of activity strength parameters have also been analyzed

Sports Culture in South Asia: Effects of Modern Bowling Action Rules on Cricket, an Information Technology Perspective

Cricket, a famous game played and watched at its peak in Asia. The game is governed by International Cricket Council (ICC). It is a team sport of eleven players in each side with different roles, of which one is bowler. The bowlers have followed different styles of bowling sinces game has started, of which some declared illegal initially. In our study, we have focused on the cases of illegality reported form South Asian region in post 1990 period a new era of biomechanics based bowling laws started. We have also investigated the updated ICC process for bowlers review and remedy along with biomechanics based labs established worldwide. Finally, we have proposed a new information technology based bowling action evaluation solution, lower in cost and affordable at domestic level. Such study will help bowlers, their coaches and viewers to understand the biomechanics based bowling laws, standings of South Asian bowling after these laws and alternative solutions to rescue it