Search results for "IFT"

The number of lifts of a Brauer character with a normal vertex

2011

AbstractIn this paper we examine the behavior of lifts of Brauer characters in p-solvable groups. In the main result, we show that if φ∈IBr(G) has a normal vertex Q and either p is odd or Q is abelian, then the number of lifts of φ is at most |Q:Q′|. As a corollary, we prove that if φ∈IBr(G) has an abelian vertex subgroup Q, then the number of lifts of φ in Irr(G) is at most |Q|.

Análisis de competitividad de las exportaciones: un nuevo enfoque shift-share

2009

Silviano.Esteve@uv.es Vicente.Pallardo@uv.es Francisco.Requena@uv.es Este trabajo utiliza un método de shift-share como herramienta para analizar la evolución de la competitividad exterior de una economía. Frente a otros indicadores tradicionales de competitividad (cuota de mercado, índice de ventaja comparativa revelada), este método ofrece una perspectiva dinámica para la evaluación de la competitividad exterior y permite descender desde niveles agregados (sectores) hasta productos específicos, identificando de este modo el origen de las ventajas-desventajas competitivas de una economía. Se presenta una aplicación para el sector de manufacturas del metal de la Comunidad Valenciana en el p…

Approximated overlap error for the evaluation of feature descriptors on 3D scenes

2013

This paper presents a new framework to evaluate feature descriptors on 3D datasets. The proposed method employs the approximated overlap error in order to conform with the reference planar evaluation case of the Oxford dataset based on the overlap error. The method takes into account not only the keypoint centre but also the feature shape and it does not require complex data setups, depth maps or an accurate camera calibration. Only a ground-truth fundamental matrix should be computed, so that the dataset can be freely extended by adding further images. The proposed approach is robust to false positives occurring in the evaluation process, which do not introduce any relevant changes in the …

Ab initio study of halogenated diphenyl ethers. NMR chemical shift prediction

2000

New super-orthogonal space-time trellis codes using differential M-PSK for noncoherent mobile communication systems with two transmit antennas

2010

Published version of an article in the journal: Annals of Telecommunications-Annales Des Telecommunications. Also available from the publisher at: http://dx.doi.org/10.1007/s12243-010-0191-1 In this paper, we develop super-orthogonal space-time trellis codes (SOSTTCs) using differential binary phase-shift keying, quadriphase-shift keying and eight-phase shift keying for noncoherent communication systems with two transmit antennas without channel state information at the receiver. Based on a differential encoding scheme proposed by Tarokh and Jafarkhani, we propose a new decoding algorithm with reduced decoding complexity. To evaluate the performance of the SOSTTCs by way of computer simulat…

Adaptive time window linear regression algorithm for accurate time synchronization in wireless sensor networks

2015

In this article we propose a new algorithm for time synchronization in wireless sensor networks. The algorithm is based on linear regression to achieve long-term synchronization between the clocks of different network motes. Since motes are built using low-cost hardware components, usually their internal local clocks are not very accurate. In addition, there are other effects that affect the clock precision, such as: environmental conditions, supply voltage, aging, manufacturing process. Because some of these causes are external and unpredictable, the clock drift between two motes can change in a random way. Due to these changes, the optimum time window used for performing the linear regres…

Numerical and experimental analysis of a high innovative hydrofoil

2020

The hydrofoil is a craft where the weight is entirely supported by the lift generated by the submerged part of wings. The particular structure of the craft requires a thorough study of the architecture of the hull, whose structure differs from others high speed vessels since the lift on wing surfaces are transmitted to the hull in limited areas (wing attacks). The authors have developed a research to optimize geometry of hull and wing system on a hydrofoil capable to carry 250 passengers at a speed of 35 knots, operating among Sicilian island. The principal goals of the new hydrofoil concern both the fuel reduction that the improvement of the comfort in terms of seakeeping and levels of aco…

A method to estimate the path gains and propagation delays of underwater acoustic channels using the arrival phase information of the multipath compo…

2017

Abstract We propose a method for the estimation of the channel parameters of underwater acoustic channels (UACs) by using a pseudo-noise (PN) sequence. For the channel sounding, the PN sequence is coherently modulated on a carrier frequency by using a binary phase-shift keying (BPSK) modulation scheme. For the demodulation, the arrival phases of the received BPSK signals must be known at the receiver. In practice, however, the arrival phases of the received signal are unknown. We propose to demodulate the received BPSK signal by using an hypothetical arrival phase, which will be increased from 0 to 2 π . The demodulated signal obtained by using the hypothetical arrival phase is then correla…

Online Multi-Person Tracking by Tracker Hierarchy

2012

Tracking-by-detection is a widely used paradigm for multi-person tracking but is affected by variations in crowd density, obstacles in the scene, varying illumination, human pose variation, scale changes, etc. We propose an improved tracking-by-detection framework for multi-person tracking where the appearance model is formulated as a template ensemble updated online given detections provided by a pedestrian detector. We employ a hierarchy of trackers to select the most effective tracking strategy and an algorithm to adapt the conditions for trackers' initialization and termination. Our formulation is online and does not require calibration information. In experiments with four pedestrian t…

A decentralized load control architecture for smart energy consumption in small islands

2020

Abstract In this paper we propose the adoption of Overgrid, a new decentralized load control architecture, for balancing the energy production variations introduced with the adoption of renewable sources, facilitating and improving the smart energy retrofit. The system is presented and applied for managing the aggregated daily load profile of a community of domestic end-users in the island of Lampedusa, Italy, exploiting the load profiles gathered in a real measurement campaign. The Overgrid Demand Response (DR) architecture is used for managing the residential flexible loads, estimating the aggregated power demand without any centralized server and creating a virtual “community” of smart b…