Kullback-Leibler Divergence-Guided Copula Statistics-Based Blind Source Separation of Dependent Signals

In this paper, we propose a blind source separation of a linear mixture of dependent sources based on copula statistics that measure the non-linear dependence between source component signals structured as copula density functions. The source signals are assumed to be stationary. The method minimizes the Kullback-Leibler divergence between the copula density functions of the estimated sources and of the dependency structure. The proposed method is applied to data obtained from the time-domain analysis of the classical 11-Bus 4-Machine system. Extensive simulation results demonstrate that the proposed method based on copula statistics converges faster and outperforms the state-of-the-art blind source separation method for dependent sources in terms of interference-to-signal ratio.Comment: Submitted to the ISGT NA 202

Apolipoprotein gene polymorphisms and plasma levels in healthy Tunisians and patients with coronary artery disease

<p>Abstract</p> <p>Aim</p> <p>To analyze apolipoprotein gene polymorphisms in the Tunisian population and to check the relation of these polymorphisms and homocysteine, lipid and apolipoprotein levels to the coronary artery disease (CAD).</p> <p>Methods</p> <p>In healthy blood donors and in patients with CAD complicated by myocardial infarction (MI) four apolipoprotein gene polymorphisms [APO (a) PNR, APO E, APO CI and APO CII] were determined and plasma levels of total homocysteine, total cholesterol (TC), triglycerides (TG), HDL-cholesterol (HLD-C) and apolipoproteins (apo A-I, Apo B, Apo E) were measured.</p> <p>Results</p> <p>Analysis of the four apolipoprotein gene polymorphisms shows a relative genetic homogeneity between Tunisian population and those on the other side of Mediterranean basin. Compared to controls, CAD patients have significantly higher main concentrations of TC, TG, LDL-C, apo B and homocysteine, and significantly lower ones of HDL-C, apo A-I and apo E. The four apolipoprotein gene polymorphisms have not showed any significant differences between patients and controls. However, the APO E4 allele appears to be associated to the severity of CAD and to high levels of atherogenic parameters and low level of apo E, which has very likely an anti-atherogenic role.</p> <p>Conclusion</p> <p>Although APO (a) PNR, APO CI and APO CII genes are analyzed in only few populations, they show a frequency distribution, which is not at variance with that of APO E gene and other widely studied genetic markers. In the Tunisian population the APO E 4 appears to be only indirectly involved in the severity of CAD. In the routine practice, in addition of classic parameters, it will be useful to measure the concentration of apo E and that of Homocysteine and if possible to determine the APO E gene polymorphism.</p

Changement de techniques pour les travaux urbains de réseau et impacts environnementaux

Les nouvelles préoccupations environnementales ont transformé les modes de fonctionnement des entreprises travaillant dans le secteur du bâtiment et des travaux publics. Il est aujourd’hui primordial de préserver la qualité de l’environnement lors d’un chantier. À l’aide d’un exemple concernant les travaux sur les réseaux sera mise en évidence la transformation des techniques pour réduire les impacts négatifs des chantiers en milieu urbain. Les travaux sur les réseaux, pourtant nécessaires – ..

A new sauropod dinosaur from the Early Cretaceous of Tunisia with extreme avian-like pneumatization

Recent interpretations of the postcranial anatomy of sauropod dinosaurs differ about pneumatic features supporting an avian-like ventilatory system; the most conservative workers reject most postcranial pneumatizations as being unambiguous evidence of abdominal air sacs. Here we describe the first articulated dinosaur skeleton from Tunisia and refer it to a new rebbachisaurid sauropod, Tataouinea hannibalis gen. et sp. nov. The Tunisian specimen shows a complex pattern of caudosacral and pelvic pneumatization—including the first report of an ischial pneumatic foramen among Dinosauria—strongly supporting the presence of abdominal air sacs. Character optimization among Rebbachisauridae indicates that in the caudal vertebrae, pneumatization of the neural arches preceded that of the centra; in the pelvis, pneumatization of the bones adjacent to the sacrum preceded that of more distal elements. Tataouinea was more closely related to European nigersaurines than to otherwise Gondwanan rebbachisaurids; this supports an Afro-European route for rebbachisaurid dispersal

Cross-cultural adaptation and psychometric properties' evaluation of the modern standard Arabic version of Cumberland Ankle Instability Tool (CAIT) in professional athletes.

PurposeTo cross-culturally adapt the Cumberland Ankle Instability Tool into modern standard Arabic and to assess its psychometric properties.MethodCross-cultural adaptation followed a combination of guidelines and for psychometric evaluation a sample of 107 athletes as recruited. All recommended measurement properties by the Consensus-based Standards for the selection of health status Measurement Instruments were evaluated, including face, structural, convergent, and discriminant validity; reproducibility; distribution-based responsiveness, and interpretability. We also used a structured content analytic method to evaluate content validity.ResultsThe tool presented excellent internal consistency (α = 0.92) and reliability (ICC 0.75-0.98), and good convergent validity compared with Lower Extremity Functional Scale (ρ = 0.67). For reproducibility testing: Minimal detectable change ranged from 0.41 to 6.0 points; for responsiveness assessment: the effect sizes were large (Glass'Δ range 2.03-2.08, Cohen's d range 2.22 to 2.53) and the Area under the Curve was 0.869. Its unidimensionality was proved by a 1-factor solution explaining 63.8% of the variance.ConclusionThe Arabic version of Cumberland Ankle Instability Tool presented acceptable psychometric properties comparable to the original version. The questionnaire is understood across most of the Arabic speaking world and can be used in research and clinical practice to assess patients suffering from chronic ankle instability

A blockchain-based architecture for secure vehicular Named Data Networks

In vehicular networks, vehicles exchange a massive amount of information aiming at improving people's safety. Most of this information is personal or sensitive in nature, which makes security and privacy indispensable tasks. Named Data Networking is a future Internet architecture that adopts content-based security and in-network caching features to improve content delivery. However, the use of Named Data Networking on top of vehicular networks brings various challenges, especially in security and trust levels. The use of the distributed and control-less in-network caching allows malicious users to use the built-in design to launch attacks at the cache-store. Moreover, a malicious node can serve invalid or unlimited Interests to start an Interest flooding attack. In this paper, we propose a reputation-based Blockchain mechanism to secure both of Interest and Data forwarding plane, and content caching. The simulation results exhibit that our solution forwards only valid Interest and caches only trust content.This work was supported by the National 242 Project under Grant No. 2017A149

Edge and fog computing for IoT: A survey on current research activities &amp; future directions

The Internet of Things (IoT) allows communication between devices, things, and any digital assets that send and receive data over a network without requiring interaction with a human. The main characteristic of IoT is the enormous quantity of data created by end-user's devices that needs to be processed in a short time in the cloud. The current cloud-computing concept is not efficient to analyze very large data in a very short time and satisfy the users’ requirements. Analyzing the enormous quantity of data by the cloud will take a lot of time, which affects the quality of service (QoS) and negatively influences the IoT applications and the overall network performance. To overcome such challenges, a new architecture called edge computing — that allows to decentralize the process of data from the cloud to the network edge has been proposed to solve the problems occurred by using the cloud computing approach. Furthermore, edge computing supports IoT applications that require a short response time and consequently enhances the consumption of energy, resource utilization, etc. Motivated by the extensive research efforts in the edge computing and IoT applications, in this paper, we present a comprehensive review of edge and fog computing research in the IoT. We investigate the role of cloud, fog, and edge computing in the IoT environment. Subsequently, we cover in detail, different IoT use cases with edge and fog computing, the task scheduling in edge computing, the merger of software-defined networks (SDN) and network function virtualization (NFV) with edge computing, security and privacy efforts. Furthermore, the Blockchain in edge computing. Finally, we identify open research challenges and highlight future research directions

A survey of Internet of Things communication using ICN: A use case perspective

Internet of Things (IoT) has gained extensive attention from industry and academia alike in past decade. The connectivity of each and every piece of technology in the environment with Internet, has opened many avenues of research and development. Applications, algorithms, trust models, devices, all have evolved to accommodate the demands of user needs in the most optimal way possible. However, one thing still remains constant: host-centric communication. It is the most predominant way of communication in Internet today. With evolution of everything else, host based communication has been stretched to limits, and exploration of new models have been underway for sometime. Information Centric Networking (ICN) is a major contender for the future Internet architecture, where content is the basic element regardless of its location (host). It intends to offer in-network caching, inherent mobility, multicast support, and content based security as part of design and not add-on functionality. In recent years, numerous efforts have been made to integrate IoT with ICN as the communication model. In this paper, we provide a detailed and systematic review of IoT–ICN research. We investigate ICN as communication enabler for IoT domain specific use cases, and the use of ICN features for the benefit of IoT networks. These include IoT device & content naming, discovery, and caching. We also survey synchronization, interoperability, publish/subscribe communication, quality of service, security, and mobility of IoT devices with ICN perspectives. The paper also presents challenges and possible research directions for the benefit of community.The work of F. Li is partially supported by the National Natural Science Foundation of China No. 61772077 , 61370192 , and the Beijing Natural Science Foundation No. 4192051 . We would like to thank the editors and reviewers for their comments and suggestions, which helped us to improve the quality, content, and presentation of this article.Scopu

Drifting buoys GDAC NetCDF data and metadata format

The present document describes the data formats recognized by the drifting buoys GDAC. The document details the NetCDF data format distributed by the GDAC. Correspondence tables between all the data formats and WIGOS metadata are also included