3D virtual laboratory for geotechnical applications: another perspective

Discrete element methods are important tools for investigating the mechanics of granular materials. In two dimensions, the reliability of these numerical approaches is increasingly being challenged, because they cannot take into account all the factors involved in the behavior of a granular medium. With new concepts, such as high performance parallel computing and 3D visualization, it is now possible to conduct numerical simulations of granular materials made up of several thousands of particles, and also to follow the evolution of the various parameters involved in the behavior of a granular medium. Experimental tests have been carried out to validate the results obtained by using a virtual laboratory. This paper presents the earlier results obtained in our 3D Virtual Laboratory on the response of specimens of glass beads of uniform size during shear tests. Good agreement was achieved between the virtual simulations and the experimental tests. This work highlights the possibility of using a new 3D virtual laboratory for dynamic simulation. This approach could be of significant value in improving the verification, validation, and communication of the simulation results of discrete element methods, which can in turn make the simulations more credible and thus useful in decision making

Market-Based Approach to Mobile Surveillance Systems

The active surveillance of public and private sites is increasingly becoming a very important and critical issue. It is, therefore, imperative to develop mobile surveillance systems to protect these sites. Modern surveillance systems encompass spatially distributed mobile and static sensors in order to provide effective monitoring of persistent and transient objects and events in a given area of interest (AOI). The realization of the potential of mobile surveillance requires the solution of different challenging problems such as task allocation, mobile sensor deployment, multisensor management, cooperative object detection and tracking, decentralized data fusion, and interoperability and accessibility of system nodes. This paper proposes a market-based approach that can be used to handle different problems of mobile surveillance systems. Task allocation and cooperative target tracking are studied using the proposed approach as two challenging problems of mobile surveillance systems. These challenges are addressed individually and collectively

WiRoTip: an IoT-based Wireless Sensor Network for Water Pipeline Monitoring

One of the key components of the Internet of Things (IoT) is the Wireless Sensor Network (WSN). WSN is an effective and efficient technology. It consists of senor nodes; smart devices that allows data collection and pre-processing wirelessly from real world. However, issues related to power consumption and computational performance still persist in classicalwireless nodes since power is not always available in application like pipeline monitoring. Moreover, they could not be usually suitable and adequate for this kind of application due to memory shortage and performance constraints. Designing new IoT WSN system that matches the application specific requirements is extremely important. In this paper, wepresent WiRoTip, a WSN node prototype for water pipeline application. An experimental and a comparative studies have been performed for the different node’s components to achieve a final adequate design

STUDY OF THE SPACE CHARGE RELAXATION IN POLY ETHER ETHER KETONE (PEEK)

Abstract The relaxation of space charge is studied by the dielectric modulus formalism in poly(ether ether ketone) (PEEK). The obtained data suggest a prevailing ohmic conduction in one specimen and interfacial polarization effect, known as the Maxwell-Wagner-Sillars polarization. The interfacial relaxation taking place at the interface between the crystalline inclusions and the amorphous matrix. It's attributed to the trapping of ionic charges at the interface between crystalline lamellae and the amorphous matrix. The conductivity must be attributed to the increasing mobility of the carriers

West Nile virus meningoencephalitis during pregnancy: Case report with MR imaging findings

AbstractMR imaging findings of West Nile virus meningoencephalitis during pregnancy are unknown. We report the first case of serologically proved West Nile virus meningoencephalitis complicating pregnancy with MRI findings. MR imaging of the brain revealed abnormal hyperintensity in the periventricular white matter near the left frontal horn and insular left lobe on fluid-attenuated inversion recovery and T2-weighted images. Evolution was favorable, and no obvious fetal consequences of infection were noted after birth. Recognition of the MR imaging appearance of this entity is important because of the expanding epidemic