scholarly journals Modeling and Characterization of the Uplink and Downlink Exposure in Wireless Networks

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Anis Krayni ◽  
Abdelhamid Hadjem ◽  
Günter Vermeeren ◽  
Alain Sibille ◽  
Christophe Roblin ◽  
...  
Keyword(s):  
Exposure Assessment ◽  
Polynomial Chaos ◽  
Base Station ◽  
Propagation Channel ◽  
Wave Interactions ◽  
Single Plane ◽  
Electromagnetic Simulations ◽  
Wireless Device ◽  
Fdtd Simulations

This paper deals with a new methodology to assess the exposure induced by both uplink and downlink of a cellular network using 3D electromagnetic simulations. It aims to analyze together the exposure induced by a personal device (uplink exposure) and that induced by a base station (downlink exposure). The study involved the major parameters contributing to variability and uncertainty in exposure assessment, such as the user’s posture, the type of wireless device, and the propagation environment. Our approach is relying basically on the modeling of the power radiated by the personal device and the ambient electric field, while taking into account the effects of human body shadowing and the propagation channel fluctuations. The exposure assessment as well as the human-wave interactions has been simulated using the finite difference in time domain method (FDTD). In uplink scenarios, four FDTD simulations were performed with a child model, used in two postures (sitting and standing) and in two usage scenarios (voice and data), which aimed to examine the exposure induced by a mobile phone and a tablet emitting, respectively, at 900 MHz and 1940 MHz. In the downlink scenario, a series of FDTD simulations of an exposure to a single plane wave and multiplane waves have been conducted, and an efficient metamodeling of the exposure using the Polynomial Chaos approach has been developed.

Exposure assessment and risk characterization of Aflatoxin M1 through consumption of market milk and milk products in Ludhiana, Punjab

Food Control ◽  
2021 ◽  
pp. 107991
Author(s):  
Simranjot Kaur ◽  
Jasbir Singh Bedi ◽  
Pankaj Dhaka ◽  
Deepthi Vijay ◽  
Rabinder Singh Aulakh
Keyword(s):  
Exposure Assessment ◽  
Aflatoxin M1 ◽  
Risk Characterization ◽  
Milk Products

scholarly journals Characterization of Tiled Architecture for C-Band 1-Bit Beam-Steering Transmitarray

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1259
Author(s):  
Dmitry Kozlov ◽  
Irina Munina ◽  
Pavel Turalchuk ◽  
Vitalii Kirillov ◽  
Alexey Shitvov ◽  
...  
Keyword(s):  
Communication Systems ◽  
Beam Steering ◽  
Unit Cell ◽  
Electromagnetic Simulations ◽  
Fifth Generation ◽  
Full Wave ◽  
Array Architecture ◽  
Modulation Pattern ◽  
Good Agreement

A new implementation of a beam-steering transmitarray is proposed based on the tiled array architecture. Each pixel of the transmitarray is manufactured as a standalone unit which can be hard-wired for specific transmission characteristics. A set of complementary units, providing reciprocal phase-shifts, can be assembled in a prescribed spatial phase-modulation pattern to perform beam steering and beam forming in a broad spatial range. A compact circuit model of the tiled unit cell is proposed and characterized with full-wave electromagnetic simulations. Waveguide measurements of a prototype unit cell have been carried out. A design example of a tiled 10 × 10-element 1-bit beam-steering transmitarray is presented and its performance benchmarked against the conventional single-panel, i.e., unibody, counterpart. Prototypes of the tiled and single-panel C-band transmitarrays have been fabricated and tested, demonstrating their close performance, good agreement with simulations and a weak effect of fabrication tolerances. The proposed transmitarray antenna configuration has great potential for fifth-generation (5G) communication systems.

Exposure assessment and risk characterization of aflatoxins intake through consumption of maize products in the adult populations of Serbia, Croatia and Greece

2019 ◽  
Vol 36 (6) ◽  
pp. 940-951 ◽  
Author(s):  
Bozidar Udovicki ◽  
Ilija Djekic ◽  
Jasenka Gajdos Kljusuric ◽  
Maria Papageorgiou ◽  
Adriana Skendi ◽  
...  
Keyword(s):  
Exposure Assessment ◽  
Risk Characterization

scholarly journals Characterization of Path Loss and Large-Scale Fading for Rapid Intervention Team Communication in Underground Parking Garages

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2431 ◽  
Author(s):  
Seppe Van Brandt ◽  
Robbe Van Thielen ◽  
Jo Verhaevert ◽  
Tanja Van Hecke ◽  
Hendrik Rogier
Keyword(s):  
Large Scale ◽  
Path Loss ◽  
Wireless Channel ◽  
Building Structure ◽  
Propagation Channel ◽  
Parking Garage ◽  
High Penetration ◽  
Parking Garages ◽  
Intervention Team

This paper reports the characterization of the 2.45-GHz-ISM-band radio wave propagation channel. Specifically, measurements were performed in an underground parking garage, with the aim of optimizing breadcrumb systems for a Rapid Intervention Team application. The effects of the high penetration loss and large reflections by the concrete reinforced building structure on the path loss and the large-scale fading were studied. Based on the analysis of the wireless channel, critical points for reliable communication between members of a Rapid Intervention Team were identified. In particular, attention was paid to dealing with large, spatially confined signal losses due to shadowing, the anticipation of corner losses and the ability of the system to operate on multiple floors.

Characterization of MIMO propagation channel at 15 GHz for the 5G spectrum

2017 ◽  
Author(s):  
Faizan Qamar ◽  
Talib Abbas ◽  
Mhd Nour Hindia ◽  
Kaharudin Bin Dimyati ◽  
Kamarul Ariffin Bin Noordin ◽  
...  
Keyword(s):  
Propagation Channel

Environmental Sampling and Exposure Assessment

2017 ◽  
Author(s):  
Morton Lippmann ◽  
Richard B. Schlesinger
Keyword(s):  
Risk Assessment ◽  
Exposure Assessment ◽  
Occupational Exposures ◽  
Environmental Sampling ◽  
Exposure Limits ◽  
Environmental Media ◽  
Biomarkers Of Exposure ◽  
General Populations

This chapter describes the characterization of occupational exposures of workers to chemicals at their job sites, and exposures of general populations to chemicals in the environmental for individuals and population groups. It also discusses: approaches to risk assessment; the determination of whether exposures exceed established exposure limits or standards; and the methodologies used to determine and/or model the concentrations of chemicals in environmental media that are used to determine the nature and extent of exposures, and of biomarkers of exposure, to individuals and populations of humans and other receptors.

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