Full-length non-linear binary sequences with Zero Correlation Zone for multiuser communications

none3noThe research on new sets of sequences that can be applied as spreading codes in multiple user communications is still an active area, even if this topic has been extensively investigated since long time. In fact, new communication paradigms like dense and decentralized wireless networks, where there is no central controller to assign the resources to the nodes, are revamping the interest on finding large sets of sequences providing adequate correlation properties to support a big number of nodes, in potentially hostile channels. This paper focuses on the Zero Correlation Zone (ZCZ) property exhibited by a family of nonlinear binary sequences featuring a great cardinality of their set, and good security-related features, and provides evidence of their suitability to multiuser communications, in channels affected by multipath.Sarayloo, M.; Gambi, E.; Spinsante, S.Sarayloo, Mahdiyar; Gambi, Ennio; Spinsante, Susann

Full-length non-linear binary sequences with Zero Correlation Zone for multiuser communications

The research on new sets of sequences to be used asspreading codes in multiple user communications is still an activearea, despite the great amount of literature available since manyyears on this topic. In fact, new paradigms like dense anddecentralized wireless networks, where there is no centralcontroller to assign the resources to the nodes, are revamping theinterest on large sets of sequences providing adequate correlationproperties to support a big number of nodes, in potentially hostilechannels. This paper focuses on the Zero Correlation Zone (ZCZ)property exhibited by a family of non-linear binary sequencesfeaturing a great cardinality of their set and good securityrelatedfeatures, and provides evidence of their suitability tomultiuser communications, in channels affected by multipath

Augmentation and Optimisation of the Australian Desert Fireball Network to Enable New Planetary Science

Planetary science is limited by the scarcity of extraterrestrial samples of known origin. Fireball camera networks can provide these in the form of meteorites with known pre-atmospheric entry orbits. Here, a new digital fireball observatory implementing a novel timing technique is described. This design has enabled the Desert Fireball Network to cover a third of Australia, recover two meteorites with orbits and observe more than a dozen additional meteorite dropping fireballs

NASA Tech Briefs, April 1990

Topics: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences

Development of a model for smart card based access control in multi-user, multi-resource, multi-level access systems

The primary focus of this research is an examination of the issues involved in the granting of access in an environment characterised by multiple users, multiple resources and multiple levels of access permission. Increasing levels of complexity in automotive systems provides opportunities for improving the integration and efficiency of the services provided to the operator. The vehicle lease / hire environment provided a basis for evaluating conditional access to distributed, mobile assets where the principal medium for operating in this environment is the Smart Card. The application of Smart Cards to existing vehicle management systems requires control of access to motor vehicles, control of vehicle operating parameters and secure storage of operating information. The issues addressed include examination of the characteristics of the operating environment, development of a model and design, simulation and evaluation of a multiple application Smart Card. The functions provided by the card include identification and authentication, secure hash and encryption functions which may be applied, in general, to a wide range of access problems. Evaluation of the algorithms implemented indicate that the Smart Card design may be provably secure under single use conditions and conditionally secure under multiple use conditions. The simulation of the card design provided data to support further research and shows the design is practical and able to be implemented on current Smart Card types

Unraveling the genetic secrets of ancient Baikal amphipods

Lake Baikal is the oldest, by volume, the largest, and the deepest freshwater lake on Earth. It is characterized by an outstanding diversity of endemic faunas with more than 350 amphipod species and subspecies (Amphipoda, Crustacea, Arthropoda). They are the dominant benthic organisms in the lake, contributing substantially to the overall biomass. Eulimnogammarus verrucosus, E. cyaneus, and E. vittatus, in particular, serve as emerging models in ecotoxicological studies. It was, then, necessary to investigate whether these endemic littoral amphipods species form genetically separate populations across Baikal, to scrutinize if the results obtained --~for example, about stress responses~-- with samples from one single location (Bolshie Koty, where the biological station is located), could be extrapolated to the complete lake or not. The genetic diversity within those three endemic littoral amphipod species was determined based on fragments of Cytochrome C Oxidase I (COI) and 18S rDNA (only for E. verrucosus). Gammarus lacustris, a Holarctic species living in water bodies near Baikal, was examined for comparison. The intra-specific genetic diversities within E. verrucosus and E. vittatus (13% and 10%, respectively) were similar to the inter-species differences, indicating the occurrence of cryptic, morphologically highly similar species. This was confirmed with 18S rDNA for E. verrucosus. The haplotypes of E. cyaneus and G. lacustris specimens were, with intra-specific genetic distances of 3% and 2%, respectively, more homogeneous, indicating no --or only recent disruption of-- gene flow of E. cyaneus across Baikal, and recent colonization of water bodies around Baikal by G. lacustris. The data provide the first clear evidence for the formation of cryptic (sub)species within endemic littoral amphipod species of Lake Baikal and mark the inflows/outflow of large rivers as dispersal barriers. Lake Baikal has provided a stable environment for millions of years, in stark contrast to small, transient water bodies in its immediate vicinity. A highly diverse endemic amphipod fauna is found in one but not the other habitat. To gain more insights and explain the immiscibility barrier between Lake Baikal and non-Baikal environments faunas, the differences in the stress response pathways were studied. To this end, exposure experiments to increasing temperature and a heavy metal (cadmium) as proteotoxic stressors were conducted in Russia. High-quality de novo transcriptome assemblies were obtained, covering multiple conditions, for three amphipod species: E. verrucosus and E. cyaneus -Baikal endemics-, and G. lacustris -Holarctic- as a potential invader. After comparing the transcriptomic stress responses, it was found that both Baikal species possess intact stress response systems and respond to elevated temperature with relatively similar changes in their expression profiles. G. lacustris reacts less strongly to the same stressors, possibly because its transcriptome is already perturbed by acclimation conditions (matching the Lake Baikal littoral). Comprehensive genomic resources are of utmost importance for ecotoxicological and ecophysiological studies in an evolutionary context, especially considering the exceptional value of Baikal as a UNESCO World Heritage Site. In that context, the results presented here, on the genome of Eulimnogammarus verrucosus, have been the first massive step to establish genomic sequence resources for a Baikalian amphipod (other than mitochondrial genomes and gene expression data in the form of de novo transcriptomes assemblies). Based on the data from a survey of its genome (a single lane of paired-end Illumina HiSeq 2000 reads, 3X) as well as a full dataset (two complete flow cells, 46X) the genome size was estimated as nearly 10 Gb based on the k-mer spectra and the coverage of highly conserved miRNA, hox genes, and other Sanger-sequenced genes. At least two-thirds of the genome are non-unique DNA, and no less than half of the genomic DNA is composed of just five families of repetitive elements, including low complexity sequences. Some of the repeats families found in high abundance in E. verrucosus seem to be species-specific, or Baikalian-specific. Attempts to use off-the-shelf assembly tools on the available low coverage data, both before and after the removal of highly repetitive components, as well as on the full dataset, resulted in extremely fragmented assemblies. Nevertheless, the analysis of coverage in Hox genes and their homeobox showed no clear evidence for paralogs, indicating that a genome duplication did not contribute to the large genome size. Several mate-pair libraries with bigger insert sizes than the 2kb used here and long reads sequencing technology combined with semi-automated methods for genome assembly seem to be necessary to obtain a reliable assembly for this species

Drones and the Creative Industry

This open access, interdisciplinary book presents innovative strategies in the use of civil drones in the cultural and creative industry. Specially aimed at small and medium-sized enterprises (SMEs), the book offers valuable insights from the fields of marketing, engineering, arts and management. With contributions from experts representing varied interests throughout the creative industry, including academic researchers, software developers and engineers, it analyzes the needs of the creative industry when using civil drones both outdoors and indoors. The book also provides timely recommendations to the industry, as well as guidance for academics and policymakers

Flood dynamics derived from video remote sensing

Flooding is by far the most pervasive natural hazard, with the human impacts of floods expected to worsen in the coming decades due to climate change. Hydraulic models are a key tool for understanding flood dynamics and play a pivotal role in unravelling the processes that occur during a flood event, including inundation flow patterns and velocities. In the realm of river basin dynamics, video remote sensing is emerging as a transformative tool that can offer insights into flow dynamics and thus, together with other remotely sensed data, has the potential to be deployed to estimate discharge. Moreover, the integration of video remote sensing data with hydraulic models offers a pivotal opportunity to enhance the predictive capacity of these models. Hydraulic models are traditionally built with accurate terrain, flow and bathymetric data and are often calibrated and validated using observed data to obtain meaningful and actionable model predictions. Data for accurately calibrating and validating hydraulic models are not always available, leaving the assessment of the predictive capabilities of some models deployed in flood risk management in question. Recent advances in remote sensing have heralded the availability of vast video datasets of high resolution. The parallel evolution of computing capabilities, coupled with advancements in artificial intelligence are enabling the processing of data at unprecedented scales and complexities, allowing us to glean meaningful insights into datasets that can be integrated with hydraulic models. The aims of the research presented in this thesis were twofold. The first aim was to evaluate and explore the potential applications of video from air- and space-borne platforms to comprehensively calibrate and validate two-dimensional hydraulic models. The second aim was to estimate river discharge using satellite video combined with high resolution topographic data. In the first of three empirical chapters, non-intrusive image velocimetry techniques were employed to estimate river surface velocities in a rural catchment. For the first time, a 2D hydraulicvmodel was fully calibrated and validated using velocities derived from Unpiloted Aerial Vehicle (UAV) image velocimetry approaches. This highlighted the value of these data in mitigating the limitations associated with traditional data sources used in parameterizing two-dimensional hydraulic models. This finding inspired the subsequent chapter where river surface velocities, derived using Large Scale Particle Image Velocimetry (LSPIV), and flood extents, derived using deep neural network-based segmentation, were extracted from satellite video and used to rigorously assess the skill of a two-dimensional hydraulic model. Harnessing the ability of deep neural networks to learn complex features and deliver accurate and contextually informed flood segmentation, the potential value of satellite video for validating two dimensional hydraulic model simulations is exhibited. In the final empirical chapter, the convergence of satellite video imagery and high-resolution topographical data bridges the gap between visual observations and quantitative measurements by enabling the direct extraction of velocities from video imagery, which is used to estimate river discharge. Overall, this thesis demonstrates the significant potential of emerging video-based remote sensing datasets and offers approaches for integrating these data into hydraulic modelling and discharge estimation practice. The incorporation of LSPIV techniques into flood modelling workflows signifies a methodological progression, especially in areas lacking robust data collection infrastructure. Satellite video remote sensing heralds a major step forward in our ability to observe river dynamics in real time, with potentially significant implications in the domain of flood modelling science

Evolutionary Computation

This book presents several recent advances on Evolutionary Computation, specially evolution-based optimization methods and hybrid algorithms for several applications, from optimization and learning to pattern recognition and bioinformatics. This book also presents new algorithms based on several analogies and metafores, where one of them is based on philosophy, specifically on the philosophy of praxis and dialectics. In this book it is also presented interesting applications on bioinformatics, specially the use of particle swarms to discover gene expression patterns in DNA microarrays. Therefore, this book features representative work on the field of evolutionary computation and applied sciences. The intended audience is graduate, undergraduate, researchers, and anyone who wishes to become familiar with the latest research work on this field

Infrastructure Design, Signalling and Security in Railway

Railway transportation has become one of the main technological advances of our society. Since the first railway used to carry coal from a mine in Shropshire (England, 1600), a lot of efforts have been made to improve this transportation concept. One of its milestones was the invention and development of the steam locomotive, but commercial rail travels became practical two hundred years later. From these first attempts, railway infrastructures, signalling and security have evolved and become more complex than those performed in its earlier stages. This book will provide readers a comprehensive technical guide, covering these topics and presenting a brief overview of selected railway systems in the world. The objective of the book is to serve as a valuable reference for students, educators, scientists, faculty members, researchers, and engineers