Localisation in wireless sensor networks for disaster recovery and rescuing in built environments

A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirements for the degree of Doctor of PhilosophyProgress in micro-electromechanical systems (MEMS) and radio frequency (RF) technology has fostered the development of wireless sensor networks (WSNs). Different from traditional networks, WSNs are data-centric, self-configuring and self-healing. Although WSNs have been successfully applied in built environments (e.g. security and services in smart homes), their applications and benefits have not been fully explored in areas such as disaster recovery and rescuing. There are issues related to self-localisation as well as practical constraints to be taken into account. The current state-of-the art communication technologies used in disaster scenarios are challenged by various limitations (e.g. the uncertainty of RSS). Localisation in WSNs (location sensing) is a challenging problem, especially in disaster environments and there is a need for technological developments in order to cater to disaster conditions. This research seeks to design and develop novel localisation algorithms using WSNs to overcome the limitations in existing techniques. A novel probabilistic fuzzy logic based range-free localisation algorithm (PFRL) is devised to solve localisation problems for WSNs. Simulation results show that the proposed algorithm performs better than other range free localisation algorithms (namely DVhop localisation, Centroid localisation and Amorphous localisation) in terms of localisation accuracy by 15-30% with various numbers of anchors and degrees of radio propagation irregularity. In disaster scenarios, for example, if WSNs are applied to sense fire hazards in building, wireless sensor nodes will be equipped on different floors. To this end, PFRL has been extended to solve sensor localisation problems in 3D space. Computational results show that the 3D localisation algorithm provides better localisation accuracy when varying the system parameters with different communication/deployment models. PFRL is further developed by applying dynamic distance measurement updates among the moving sensors in a disaster environment. Simulation results indicate that the new method scales very well

Secretin interactions in the type II secretion system

PhDThe type II secretion system (T2SS) is the major terminal branch of the general secretory pathway. It is composed of 12-15 proteins, most in multiple copies, and spans the inner and outer membranes of Gram-negative bacteria. The T2SS secretin subunits form a large dodecameric torus-like structure in the outer membrane. The secretin is the only essential component in the outer membrane and secreted proteins and virulence factors pass through the pore in the toroidal secretin dodecamer and out into the environment. The interaction between the secretin and its partners plays a key role in regulation of the T2SS. The interaction between the so-called homology region of the innermembrane protein GspC (GspC-HR) and secretin provides the structural and functional integrity of the secretion machinery across the two cell membranes. The interaction between secretin and its pilotin translocates the secretin subunits to the outer membrane. In this Thesis, the interactions between secretin and its partners are studied at molecular level. The GspC-HR structure is solved using NMR spectroscopy. Its interaction with secretin (GspD) is elucidated using several biochemical and biophysical approaches and a model of the complex is proposed. Also, the interaction between secretin (GspD) and pilotin (GspS) is further charicterisied. An 18 residues secretin sequence is identified as responsible for interacting with pilotin. Upon binding to the pilotin, the unstructured secretin forms a helical structure.MRC NMR centre (NIMR), Medical Research CouncilNational Institute for Medical Research (NIMR) N.M.R. Centr

EXCEL Advanced Tips and Tricks: Filter, Data Sort, Pivot Table, and Graphics

This session will use the spreadsheet that contains the 2015 Small Area Health Insurance Estimates for all counties and states of the United States to demonstrate several functions and tools in EXCEL for data tabulation, analysis, and presentation. The functions and tools include advanced sorting, filtering, and pivot table. The session will also include a demonstration of using graphic tools in EXCEL to present the data. Data visualization is a simple tool for sharing a dataset\u27s story with an audience, no matter what their background. Trends and population percentages are just two items that can be creatively displayed in EXCEL. We\u27ll learn how to create the visualizations that can help take presentations to the next level

Black Hole Fundamental Plane in Low-Excitation Radio Galaxies

The radio-X-ray slope in the fundamental plane of radio-loud active galactic nuclei (AGNs) is found to be steeper compared with that of radio-quiet AGNs in previous works. In this work, we reinvestigate the fundamental plane in radio-loud AGNs by compiling a sample of 13 low-excitation radio galaxies (LERG) from the 3CR radio galaxies, for the reason that the accretion mode in LERG is believed to be a radiatively inefficient accretion flow. All the sources in our sample possess the data available at both the 5 GHz core radio luminosity detected by VLA/VLBI/VLBA and the core X-ray luminosity detected by Chandra/XMM-Newton. Surprisingly, we find the slope in the fundamental plane ($\log L_{\rm R}=0.52 \log L_{\rm X}+ 0.84 \log M_{\rm BH} + 10.84$) of LERG is well consistent with that reported by \citet{m2003}. However, the normalization is found to be shifted by about 0.7 dex, which can be due to the difference on magnetic field strength in different objects. A shallower slope of $L_{\rm R}-L_{\rm X}$ relation ($L_{\rm R}\sim L_{\rm X}^{0.63}$) is also given by our sample, which demonstrates that the X-ray emission in LERG may come from accretion disc instead of jets as suggested by previous works.Comment: 12 pages, 3 figures, 1 table, accepted by MNRAS Letter

The Ultraviolet/optical variability of steep-spectrum radio quasars: the change in accretion rate ?

Context. The steep-spectrum radio quasars (SSRQs) are powerful radio sources, with thermal emission from accretion disk and jet nonthermal emission likely both contributing in the Ultraviolet (UV)/optical luminosity, however the former may play a dominant role. While the UV/optical variability of SSRQs has been poorly studied, little is known on the mechanism of their variability. Aims. We investigate the mechanism of the UV/optical variability of SSRQs. Methods. A sample of eighteen SSRQs has been established in SDSS Stripe 82 region in our previous works, in which the flux and spectral variability have been studied. In this work, we construct the flux-flux diagram using SDSS u and i multi-epoch data for these eighteen SSRQs. The standard accretion disk model is used to fit the flux-flux variations, in order to explore the variability mechanism. Results. The model fit to flux-flux diagram are tuned with fixed black hole mass and varying accretion rate. We found that the flux-flux diagram of all our SSRQs can be qualitatively described by the standard accretion disk model with change of the accretion rate. Although non-thermal jet power-law emission can also qualitatively reproduce the variability, the reasonable accretion rates and black hole masses required to fit the flux-flux variations suggest that a disk emission with variable accretion rate is a plausible description of the data.Comment: 9 pages, 2 figures, 1 table, accepted to A&A, title change

Hexyl (E)-3-(3,4-dihy­droxy­phen­yl)acrylate

The title mol­ecule, C15H20O4, has an E conformation about its C=C bond and is almost planar (r.m.s. deviation of all non-H atoms = 0.04 Å). The crystal structurere features O—H⋯O and C—H⋯O hydrogen bonds

Page Load Performance Evaluation for Mobile Browser on a Cloud Computing Platform

More and more network data flows of the Internet are nowadays contributed by wireless access which is initiated from mobile devices, such as smartphones and tablets. As a result, the performance of mobile browser applications integrated in software stacks of these portable devices draws more and more attentions. In order to meet the needs of software engineering and benchmarking among various device vendors particularly, it is getting increasingly important to evaluate the performance of mobile browser accurately and efficiently. However, due to the distinct hardware and software characteristics, conventional measurement methods which are widely deployed in desktop browsing are not so applicable for mobile browsers. This study tries to solve this problem by finding out a practical approach to evaluate the page load performance of mobile browsers without additional software and hardware measurement investments. Several measurement models are therefore introduced, discussed and evaluated in order to point out the accurate and efficient one. As a benchmarking tool, an online measurement application is designed and implemented in the experimental part of this study. Verification data are then analyzed and discussed. The implementation of such a web application and its context of the evaluation model provide an outline of an ideal approach to benchmark page load performance of mobile browsers. This optimized approach not only reduces the complexity of configuring a measurement environment for mobile devices, but also provides relatively accurate measurement results for continuous evaluation of mobile browsers' page loading speed, which is useful for developers to increase mobile browser's performance incrementally. The collected measurement results using such a measurement model are also useful as a reference for benchmarking various mobile browsers from different manufacturers. Our research found out also possible factors which may influence to the performance of mobile browsers. The practice targeting of these factors, such as the design of web pages, will help users of mobile devices to achieve better user experience when surfing the Internet

(E)-Isopentyl 3-(3,4-dihy­droxy­phen­yl)­acrylate

The title compound, C14H18O4, a derivative of caffeic acid, has an E configuration about the C=C bond. The benzene ring is almost coplanar with the C=C—C(O)—O—C linker [maximum deviation = 0.050 (2) Å], making a dihedral angle of only 4.53 (2)°. In the mol­ecule, the adjacent hy­droxy groups form an O—H⋯O inter­action. In the crystal, mol­ecules are linked by O—H⋯O hydrogen bonds, generating a chain propagating in the [110] direction