Search results for "Tracking"
showing 10 items of 709 documents
A pre-processing and network analysis of GPS tracking data
2020
Global Positioning System (GPS) devices afford the opportunity to collect accurate data on unit movements from temporal and spatial perspectives. With a special focus on GPS technology in travel surveys, this paper proposes: (1) two algorithms for the pre-processing of GPS data in order to deal with outlier identification and missing data imputation; (2) a clustering approach to recover the main points of interest from GPS trajectories; and (3) a weighted-directed network, which incorporates the most relevant characteristics of the GPS trajectories at an aggregate level. A simulation study shows the goodness-of-fit of the imputation data algorithm and the robustness of the clustering algori…
Motion and force analysis of slow-speed multi-trailer systems
2018
Comparing with the tractor-trailer systems for the road haulage, which must cope with some typical undesired trends, such as high-speed instability, over- or under-steering and off-tracking, the multi-trailer systems for the transport of luggage in the airports or in the railway stations, or for the transfer of goods in the warehouses, run at quite low speeds, but must manage to steer clear of the many obstacles encountered along their path. This type of vehicle is not subject to tire cornering phenomena, because the speed is just low and the wheels are generally stiff. Hence, the vehicle movement is in practice ruled by the non-holonomic rolling constraint of the wheels and by the steerin…
Adaptive PI Control of Bottom Hole Pressure during Oil Well Drilling
2018
Abstract In this paper, we studied the bottom hole pressure (BHP) control in an oil well during drilling. Today marginal wells with narrow pressure windows are frequently being drilled. This requires accurate and precise control to balance the bottom hole pressure between the pore and fracture pressure of the reservoir. This paper presents three control schemes to stabilize the BHP prole, including proportional-integral(PI) control, PI with feed-forward control and adaptive PI with feed-forward control. The proposed schemes are carried out through simulations on a high-fidelity hydraulic drilling simulator for flow rate changes and BHP set-point changes. In fast set-point changes and flow r…
A Multi-Scale Colour and Keypoint Density-Based Approach for Visual Saliency Detection
2020
In the first seconds of observation of an image, several visual attention processes are involved in the identification of the visual targets that pop-out from the scene to our eyes. Saliency is the quality that makes certain regions of an image stand out from the visual field and grab our attention. Saliency detection models, inspired by visual cortex mechanisms, employ both colour and luminance features. Furthermore, both locations of pixels and presence of objects influence the Visual Attention processes. In this paper, we propose a new saliency method based on the combination of the distribution of interest points in the image with multiscale analysis, a centre bias module and a machine …
On the use of Deep Reinforcement Learning for Visual Tracking: a Survey
2021
This paper aims at highlighting cutting-edge research results in the field of visual tracking by deep reinforcement learning. Deep reinforcement learning (DRL) is an emerging area combining recent progress in deep and reinforcement learning. It is showing interesting results in the computer vision field and, recently, it has been applied to the visual tracking problem yielding to the rapid development of novel tracking strategies. After providing an introduction to reinforcement learning, this paper compares recent visual tracking approaches based on deep reinforcement learning. Analysis of the state-of-the-art suggests that reinforcement learning allows modeling varying parts of the tracki…
An Indoor and Outdoor Navigation System for Visually Impaired People
2019
In this paper, we present a system that allows visually impaired people to autonomously navigate in an unknown indoor and outdoor environment. The system, explicitly designed for low vision people, can be generalized to other users in an easy way. We assume that special landmarks are posed for helping the users in the localization of pre-defined paths. Our novel approach exploits the use of both the inertial sensors and the camera integrated into the smartphone as sensors. Such a navigation system can also provide direction estimates to the tracking system to the users. The success of out approach is proved both through experimental tests performed in controlled indoor environments and in r…
A general framework for collecting and analysing the tracking data of cruise passengers at the destination
2016
Cruise passengers’ behaviour at the destination is a rather poorly investigated phenomenon. The single exit/entry point and the relatively brief visiting time, which characterize cruise passengers’ experience at their destinations, make the use of GPS technology particularly suitable for the analysis of such a relevant phenomenon. The aim of this research is to propose a general framework for collecting and analysing GPS tracking data relating to cruise passengers’ behaviour at their destination. The main prerequisites and research stages for the implementation of surveys on cruise passengers will be described and a set of tools and measures for the analysis of GPS tracking data will be pro…
Children’s Generalization of Novel Relational Nouns in Comparison Contexts
2021
Comparison settings (i.e. several stimuli introduced simultaneously) favor novel word learning and generalization. This study investigates the temporal dynamics of 6-year-olds solving strategies in a relational noun (e.g. “x is the dax for y”) comparison and generalization task with eye tracking data. We manipulated conceptual distance between the task’s items and recorded children’s performances and eye tracking data. We analyze and interpret solving strategies following the predictions made by two hypotheses, the Projection-First and Alignment-first. Eye tracking data clearly revealed that children, first, extract the relation from comparisons of items within a pair and search for a match…
Tracking of Television Viewing Time during Adulthood: The Young Finns Study.
2016
Purpose: The aim of this study was to investigate the tracking of television viewing (TV) time as an indicator of sedentary behavior among adults for a period of 25 yr. Methods: A random sample of 1601 subjects (740 men) age 18, 21, and 24 yr participated in the Cardiovascular Risk in Young Finns Study in 1986. TV time during leisure time was measured with a single self-report question at baseline and in 2001, 2007, and 2011. Tracking of TV time was analyzed using Spearman rank correlations and simplex models. Level and change of TV time were examined using linear growth modeling. Results: The 4- and 6-yr integrated TV time stability coefficients, adjusted for measurement errors, were Q0.60…
School Tracking and Mental Health
2019
To understand how the type of education affects long-term mental health, we examine the effects of a comprehensive school reform on mental health–related hospitalizations and deaths. The reform postponed the tracking of students into vocational and academic schools from age 11 to age 16, thus affecting the set of peers and the curriculum to which these students were exposed. The reform was implemented gradually across Finnish municipalities between 1972 and 1977. We use difference-in-differences variation and administrative data. Our overall results show no discernible effects on mental health–related hospitalizations or deaths, but heterogeneity analysis shows an adverse effect on hospital…