Achievable Rate Regions for Two-Way Relay Channel using Nested Lattice Coding

This paper studies Gaussian Two-Way Relay Channel where two communication nodes exchange messages with each other via a relay. It is assumed that all nodes operate in half duplex mode without any direct link between the communication nodes. A compress-and-forward relaying strategy using nested lattice codes is first proposed. Then, the proposed scheme is improved by performing a layered coding : a common layer is decoded by both receivers and a refinement layer is recovered only by the receiver which has the best channel conditions. The achievable rates of the new scheme are characterized and are shown to be higher than those provided by the decode-and-forward strategy in some regions.Comment: 27 pages, 13 figures, Submitted to IEEE Transactions on Wireless Communications (October 2013

Preliminary Results on 3D Channel Modeling: From Theory to Standardization

Three dimensional beamforming (3D) (also elevation beamforming) is now gaining a growing interest among researchers in wireless communication. The reason can be attributed to its potential to enable a variety of strategies like sector or user specific elevation beamforming and cell-splitting. Since these techniques cannot be directly supported by current LTE releases, the 3GPP is now working on defining the required technical specifications. In particular, a large effort is currently made to get accurate 3D channel models that support the elevation dimension. This step is necessary as it will evaluate the potential of 3D and FD(Full Dimensional) beamforming techniques to benefit from the richness of real channels. This work aims at presenting the on-going 3GPP study item "Study on 3D-channel model for Elevation Beamforming and FD-MIMO studies for LTE", and positioning it with respect to previous standardization works

Accessibility as an integral factor in e-government web site evaluation: The case of Dubai e-government

Purpose: The purpose of this paper is to examine the extent to which accessibility is taken into account in the assessment and ranking of e-government web sites through the lens of a specific study related to Dubai e-government. Design/methodology/approach: The paper considers a case study related to Dubai e-government and it evaluates the accessibility of each of the 21 Dubai e-government web sites, based on the Web Content Accessibility Guidelines (WCAG) 2.0 and using an automated accessibility testing tool. A bivariate correlation analysis is performed to assess the correlation between web site ranking and accessibility score. Findings: The research reveals that contrary to common intuition and some earlier studies, there is a weak correlation between e-government web site ranking score and web site accessibility. Research limitations/implications: The paper uses an accessibility metric that is a proxy indicator of web accessibility and is not a real assessment of accessibility as experienced by a person with disability. Practical implications: When re-examined through the lens of Rawls\u27s moral theory, this research suggests that accessibility should be given a higher priority in the general evaluation and ranking of e-government web sites. Social implications: The paper promotes universal accessibility to e-government information and services. Originality/value: The paper uses ethical arguments to highlight the need to comprehensively consider accessibility as a major criterion in the assessment and ranking of e-government web sites. © Emerald Group Publishing Limited

AI and machine learning: A mixed blessing for cybersecurity

While the usage of Artificial Intelligence and Machine Learning Software (AI/MLS) in defensive cybersecurity has received considerable attention, there remains a noticeable research gap on their offensive use. This paper reviews the defensive usage of AI/MLS in cybersecurity and then presents a survey of its offensive use. Inspired by the System-Fault-Risk (SFR) framework, we categorize AI/MLS-powered cyberattacks by their actions into seven categories. We cover a wide spectrum of attack vectors, discuss their practical implications and provide some recommendations for future research

Finite Dimension Wyner-Ziv Lattice Coding for Two-Way Relay Channel

International audienceTwo-way relay channel (TWRC) models a cooperative communication situation performing duplex transmission via a relay station. For this channel, we have shown previously that a lattice-based physical layer network coding strategy achieves, at the limit of arbitrarily large dimension, the same rate as that offered by the random coding-based regular compress-and-forward. In this paper, we investigate a practical coding scheme using finite dimension lattices and offering a reasonable performance-complexity trade-off. The algorithm relies on lattice based quantization for Wyner-Ziv coding. We characterize the rate region allowed by our coding scheme, discuss the design criteria, and illustrate our results with some numerical examples

Analysis of WCAG 2.0 data accessibility success criterion of e-government websites

© 2019, International University of Sarajevo. An accessible website enables the access to information and interaction for many people with disabilities so these people can contribute more effectively in the society. Today, most governments are enforcing their websites to follow the www consortium (w3c)\u27s Web Content Accessibility Guidelines (WCAG 2.0). This paper investigates the WCAG 2.0 success criterions that make a website accessible and explores the most violated WCAG 2.0 success criterions by the developers of e-Government websites

Transmission applicative multipoint pour les réseaux ad-hoc

AOMP (Ad-hoc Overlay Multicast Protocol) est une nouvelle approche pour la transmission applicative multipoint dans les réseaux ad-hoc mobiles. En exploitant les propriétés de routage IP, nous introduisons, dans une première étape, un algorithme distribué de correspondance des chemins permettant d'extraire des informations sur la topologie physique. Dans une seconde étape, nous construisons un arbre de transmission efficace à moindre coûts et s'adaptant à la mobilité des noeuds ad-hoc. Nous mettons en place un algorithme de raffinement pour améliorer les performances globales de la structure AOMP en cours de transmission. Les résultats de simulations montrent que AOMP, comparé à de récents protocoles multipoints applicatifs, diminue le délai de transmission, évite les redondances de paquets sur un même lien physique avec peu de pertes, en particulier en cas de mobilité des noeuds ad-hoc

034 Creatinine clearance and adverse hospital outcomes in patients with myocardial infarction

IntroductionNormal renal function has been Shown in epidemiological studies and clinical trials to be an independent predictor of survival.ObjectiveTo determine whether creatinine clearance at the time of hospital admission is an independent predictor of hospital mortality and adverse outcomes in patients with ST-segment elevation myocardial infarction (STEMI).Patients231 patients hospitalized with STEMI in our institution between January 2005 to December 2006.In-hospital outcomes were compared for patients with creatinine clearance rates of > 60ml/min (normal renal function) and ≤60ml/min (moderate and severe Baseline Renal Dysfunction, BRD).ResultsPatients with BRD were older, were more likely to be women, and presented to with more comorbidites.Patients with BRD had presented more ischemic atrial fibrillation (p = 0.033).A greater number of patients with BRD had impaired left ventricle systolic performance, so this patients had more presented acute heart failure (p = 0.008), and cardiogenic shock (p = 0.017).Patients with worsened renal function had presented more mechanical complications:-free wall rupture and apical ventricular septal defect, in two separate cases, following anterior myocardial infarction, leading to immediate death of these two patients.-ischemic mitral regurgitation in one caseThe in hospital death rate of BRD patients was 6.6%, compared with 0.9% for non BRD patients.In comparison with patients with normal or minimally impaired renal function, patients with moderate renal dysfunction were seven times more likely to die (odds ratio 7, 09, 95% confidence interval 0.7 to 68) after adjustment for other potentially confounding Variables.The risk of bleeding episodes was increased in patients with worsened renal functionOnly one patient, with moderate renal dysfunction, had an ischemic stroke.ConclusionIn patients with ACS, creatinine clearance is an important independent predictor of hospital death