Search results for "Computer science"
showing 10 items of 22367 documents
A Velocity Estimation Technique for a Monocular Camera Using mmWave FMCW Radars
2021
Perception in terms of object detection, classification, and dynamic estimation (position and velocity) are fundamental functionalities that autonomous agents (unmanned ground vehicles, unmanned aerial vehicles, or robots) have to navigate safely and autonomously. To date, various sensors have been used individually or in combination to achieve this goal. In this paper, we present a novel method for leveraging millimeter wave radar’s (mmW radar’s) ability to accurately measure position and velocity in order to improve and optimize velocity estimation using a monocular camera (using optical flow) and machine learning techniques. The proposed method eliminates ambiguity in optical flow veloci…
Localization of Multi-Class On-Road and Aerial Targets Using mmWave FMCW Radar
2021
mmWave radars play a vital role in autonomous systems, such as unmanned aerial vehicles (UAVs), unmanned surface vehicles (USVs), ground station control and monitoring systems. The challenging task when using mmWave radars is to estimate the accurate angle of arrival (AoA) of the targets, due to the limited number of receivers. In this paper, we present a novel AoA estimation technique, using mmWave FMCW radars operating in the frequency range 77–81 GHz by utilizing the mechanical rotation. Rotating the radar also increases the field of view in both azimuth and elevation. The proposed method estimates the AoA of the targets, using only a single transmitter and receiver. The measurements are…
Classification of Targets Using Statistical Features from Range FFT of mmWave FMCW Radars
2021
Radars with mmWave frequency modulated continuous wave (FMCW) technology accurately estimate the range and velocity of targets in their field of view (FoV). The targeted angle of arrival (AoA) estimation can be improved by increasing receiving antennas or by using multiple-input multiple-output (MIMO). However, obtaining target features such as target type remains challenging. In this paper, we present a novel target classification method based on machine learning and features extracted from a range fast Fourier transform (FFT) profile by using mmWave FMCW radars operating in the frequency range of 77–81 GHz. The measurements are carried out in a variety of realistic situations, including p…
Tapology: A Game-Based Platform to Facilitate E-Health and E-Inclusion
2014
Published version of a chapter in the book: Universal Access in Human-Computer Interaction. Aging and Assistive Environments. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-319-07446-7_36 We have developed a tablet computer game app for low vision users that can be used to introduce a platform for gaming, internet and visual rehabilitation to older users who have not had prior experience with information communication technology (ICT). Our target user group is people diagnosed with Age Related Macular Degeneration (AMD). The primary goal of the app is to present a fun and engaging means for participants to engage with Information Communication Technology (ICT). A long…
Estereotipos asociados al cuerpo humano: análisis de aplicaciones móviles usadas en la educación físico-deportiva
2022
Institutions and educators are massively and uncritically integrating digital curricular materials in their teaching praxis. This article aims to uncover whether health and fitness APP images convey or legitimize stereotypes linked to bodies, focusing on gender, race, somatotype and physical activity practice. We also analyse whether these apps are adequate for the recommended age or whether they are designed by physical education professionals. For that purpose, we designed a descriptive, comparative study based on content analysis on a sample of 373 images from 128 apps selected through a PRISMA review and a pilot test. Our results report that bodies reproduce a series of stereotypes: of …
Test Methods for the Evaluation of Manufacturing Mobile Manipulator Safety
2016
International audience; This paper presents a test methodology for evaluating the safety of mobile manipulators (robot arms mounted on mobile bases). This methodology addresses the safety concerns relevant to modern, agile, manufacturing practices in which mobile manipulators will play a significant role. We consider 1) the unique capabilities and anticipated uses of mobile manipulators and 2) the potential exemptions and special cases in which their behavior may be unpredictable or otherwise contrary to the safety requirements. Finally, we define metrics for assessing compliance with functional safety requirements and anticipated performance.
Customers' Perceived Risk and Trust in Using Mobile Money Services—an Empirical Study of Ghana
2019
Although mobile money (MM) has been explored in the existing literature, the roles of trust and risk in MM use have received little attention from researchers. Furthermore, many of the existing studies have treated these constructs as unidimensional. The extant literature also shows that perceived risk has received little attention from researchers who have conducted studies on MM. Thus, the objective of this study is to examine the roles of trust and perceived risk in customers' intent to adopt MM services in Ghana. Both trust and perceived risk were broken down into various dimensions. The study involved 671 respondents who were selected via an intercept approach and an online survey. Str…
An Exact Solution for the Level-Crossing Rate and the Average Duration of Fades of the Envelope of Sum-of-Cisoids Processes
2012
Authors version of an article published in the journal: Procedia Technology. Also available from the publisher at: http://dx.doi.org/10.1016/j.protcy.2012.03.004 Sum-of-cisoids (SOC) processes provide a physically and numerically appealing framework for the modelling and simulation of a wide class of mobile radio channels. This paper is concerned with the problem of finding a general solution for the level-crossing rate (LCR) and the average duration of fades (ADF) of the envelope of SOC processes. Exact expressions are derived for the LCR and the ADF by taking into account that the inphase component, the quadrature component, and the time derivatives of the inphase and quadrature component…
Ecologists overestimate the importance of predictor variables in model averaging: a plea for cautious interpretations.
2014
Abstract: Information-theory procedures are powerful tools for multimodel inference and are now standard methods in ecology. When performing model averaging on a given set of models, the importance of a predictor variable is commonly estimated by summing the weights of models where the variable appears, the so-called sum of weights (SW). However, SWs have received little methodological attention and are frequently misinterpreted. We assessed the reliability of SW by performing model selection and averaging on simulated data sets including variables strongly and weakly correlated to the response variable and a variable unrelated to the response. Our aim was to investigate how useful SWs are …
An EEMD Aided Comparison of Time Histories and Its Application in Vehicle Safety
2017
In the context of signal processing, the comparison of time histories is required for different purposes, especially for the model validation of vehicle safety. Most of the existing metrics focus on the mathematical value only. Therefore, they suffer the measuring errors, disturbance, and uncertainties and can hardly achieve a stable result with a clear physical interpretation. This paper proposes a novel scheme of time histories comparison to be used in vehicle safety analysis. More specifically, each signal for comparison is decomposed into a trend signal and several intrinsic mode functions (IMFs) by ensemble empirical mode decomposition. The trend signals reflect the general variation a…