Search results for "Telecommunication"
showing 10 items of 1769 documents
Hand Held 3D Scanning for Cultural Heritage: Experimenting Low Cost Structure Sensor Scan
2017
In the last years 3D scanning has become an important resource in many fields, in particular it has played a key role in study and preservation of Cultural Heritage. Moreover today, thanks to the miniaturization of electronic components, it has been possible produce a new category of 3D scanners, also known as handheld scanners. Handheld scanners combine a relatively low cost with the advantage of the portability. The aim of this chapter is two-fold: first, a survey about the most recent 3D handheld scanners is presented. As second, a study about the possibility to employ the handheld scanners in the field of Cultural Heritage is conducted. In this investigation, a doorway of the Benedictin…
Integrated three-dimensional models for noninvasive monitoring and valorization of the Morgantina silver treasure (Sicily)
2016
The Morgantina silver treasure belonging to the Archaeological Museum of Aidone (Sicily) was involved in a three-dimensional (3-D) survey and diagnostics campaign for monitoring the collection over time in anticipation of their temporary transfer to the Metropolitan Museum of Art in New York for a period of 4 years. Using a multidisciplinary approach, a scientific and methodological protocol based on noninvasive techniques to achieve a complete and integrated knowledge of the precious items and their conservation state, as well as to increase their valorization, has been developed. All acquired data, i.e., 3-D models, ultraviolet fluorescence, x-ray images, and chemical information, will be…
A novel frequency reuse scheme for coordinated multi-point transmission
2010
La transmisión multipunto coordinada (CoMP) se considera en 3GPP LTE-Advanced como una técnica clave para mejorar el rendimiento en el borde de la célula. Con el fin de apoyar la asignación conjunta de asignación de recursos entre células coordinadas en sistemas CoMP, es necesario diseñar esquemas eficientes de reutilización de frecuencias. Sin embargo, la mayoría de los esquemas de reutilización de frecuencias existentes no son adecuados para transmisión CoMP debido a que no consideran el escenario de transmisión conjunta multicelular en su regla de reutilización de frecuencias. Para resolver este problema, en este trabajo se propone un esquema de reutilización de frecuencias que divide el…
Sequential design of multioverlapping controllers for structural vibration control of tall buildings under seismic excitation
2012
In this article, a computationally effective strategy to obtain multioverlapping controllers via the inclusion principle is applied to design a state-feedback multioverlapping linear-quadratic regulator controller for a 20-story building. The proposed semidecentralized controller only requires state information of neighboring stories to compute the corresponding control actions. This particular information exchange configuration allows introducing a dramatic reduction in the transmission range required for a wireless implementation of the communications system. More specifically, just a one-story transmission range is required by the proposed multioverlapping controller, while a full-buildi…
The Community Response to Aircraft Noise Around Six Spanish Airports
1993
Abstract The community response to aircraft noise has been studied through a social survey. A total of 1800 persons living in the vicinity of six major Spanish airports have been interviewed at their homes concerning the environmental quality of the area, dissatisfaction with road traffic noise and aircraft noise, activities interfered with by noise, most disturbing aircraft types, and subjective evaluation of airport impact. All the responses obtained in this survey have been compared with aircraft noise levels corresponding to the residence locations of the people interviewed (values of NEF levels were calculated with the INM model). The results obtained in this work allow one to evaluate…
Intrusion Detection and Ejection Framework Against Lethal Attacks in UAV-Aided Networks: A Bayesian Game-Theoretic Methodology
2017
International audience; Advances in wireless communications and microelectronics have spearheaded the development of unmanned aerial vehicles (UAVs), which can be used to augment a ground network composed of sensors and/or vehicles in order to increase coverage, enhance the end-to-end delay, and improve data processing. While UAV-aided networks can potentially find applications in many areas, a number of issues, particularly security, have not been readily addressed. The intrusion detection system is the most commonly used technique to detect attackers. In this paper, we focus on addressing two main issues within the context of intrusion detection and attacker ejection in UAV-aided networks…
Design of Wideband MIMO Car-to-Car Channel Models Based on the Geometrical Street Scattering Model
2012
Published version of an article in the journal: Modelling and Simulation in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2012/264213 Open access We propose a wideband multiple-input multiple-output (MIMO) car-to-car (C2C) channel model based on the geometrical street scattering model. Starting from the geometrical model, a MIMO reference channel model is derived under the assumption of single-bounce scattering in line-of-sight (LOS) and non-LOS (NLOS) propagation environments. The proposed channel model assumes an infinite number of scatterers, which are uniformly distributed in two rectangular areas located on both sides of the street. Analytical solutions a…
Market Opportunity of China Telecom 3G Toward 4G - A Social-Technical Analysis for its Future Development
2013
In the Information and communication Technology (ICT) field, the success a new player will face is the challenge for the opportunity of new market development. China's mobile subscribers grew by 9.93 millions to 1.132 billions in February 2013.The convenience of communication prompted China’s growth, but there is little information available in literature about how it happened and what the next development steps will be for the China Telecom Industry.The purpose of this paper is an attempt to picture the future growth path of China Telecom market opportunities from 3G toward 4G and beyond, including viewing this from the angles of telecom/internet e-commerce regulation development; globaliz…
Spectrum sensing challenges: blind sensing and sensing optimization
2016
By any measure, wireless communications is one of the most evolving fields in engineering. This, in return, has imposed many challenges, especially in handling the hunger for higher data rates in the next generation wireless networks. Among these challenges is how to provide the needed resources in terms of the electromagnetic radio spectrum for these networks. In this regard, cognitive radio (CR) based on dynamic spectrum access (DSA) has been attracting huge attention as a promising solution for more efficient utilization of the available radio spectrum. DSA is based on finding and opportunistically accessing the free-of-use portions of spectrum. To facilitate DSA, spectrum sensing can be…
A Novel Wideband MIMO Car-to-Car Channel Model Based on a Geometrical Semi-Circular Tunnel Scattering Model
2016
In this paper, we present a wideband multiple-input multiple-output (MIMO) car-to-car (C2C) channel model based on a geometrical semi-circular tunnel (SCT) scattering model. From the geometrical SCT scattering model, a reference channel model is derived under the assumption of single-bounce scattering in line-of-sight (LOS) and non-LOS (NLOS) propagation environments. In the proposed reference channel model, it is assumed that an infinite number of scatterers are randomly distributed on the tunnel wall. Starting from the geometrical scattering model, the time-variant transfer function (TVTF) is derived, and its correlation properties in time, frequency, and space are studied. Expressions ar…