Search results for " tracker"
showing 10 items of 52 documents
New ALICE detectors for Run 3 and 4 at the CERN LHC
2020
Abstract Run 3 at the CERN LHC is scheduled to start in March 2021. In preparation for this new data taking period the ALICE experiment is making major modifications to its subsystems and is introducing three new detectors: the new Inner Tracking System, the Muon Forward Tracker, and the Fast Interaction Trigger. The new detectors will enhance tracking, especially at low transverse momenta, improve vertexing, provide the required triggering, fast timing, luminosity, and forward multiplicity functionality. For instance, it will be possible to measure beauty from displaced J/ ψ vertices down to transverse momenta p T ∼ 0 and improve precision for the ψ (2S) measurements. The upgraded ALICE wi…
Design of a sun tracker for the automatic measurement of spectral irradiance and construction of an irradiance database in the 330-1100 nm range
2007
Abstract An automatic global and direct solar spectral irradiance system has been designed based on two LICOR spectroradiometers equipped with fibre optics and remote cosine sensors. To measure direct irradiance a sun tracker based on step motors has been developed. The whole system is autonomous and works continuously. From the measurements provided by this system a spectral irradiance database in the 330–1100 nm range has been created. This database contains normal direct and global horizontal irradiances as well as diffuse irradiance on a horizontal plane, together with total atmospheric optical thickness and aerosol optical depth.
In-flight performance of the DAMPE silicon tracker
2018
Abstract DAMPE (DArk Matter Particle Explorer) is a spaceborne high-energy cosmic ray and gamma-ray detector , successfully launched in December 2015. It is designed to probe astroparticle physics in the broad energy range from few GeV to 100 TeV. The scientific goals of DAMPE include the identification of possible signatures of Dark Matter annihilation or decay, the study of the origin and propagation mechanisms of cosmic-ray particles, and gamma-ray astronomy . DAMPE consists of four sub-detectors: a plastic scintillator strip detector, a Silicon–Tungsten tracKer–converter (STK), a BGO calorimeter and a neutron detector . The STK is composed of six double layers of single-sided silicon mi…
Test-retest reliability of survey items on ownership and use of physical activity trackers
2019
Background: Researchers are interested in using digital tools, such as physical activity trackers (PAT), to promote and measure physical activity. PAT is a fast-growing research area that measures movement therefore, reliable questions on the ownership and use of PATs among adolescent populations need to be developed. Objective: The aim of this study was to conduct an intra-rater test-retest reliability study on PAT survey items used for surveillance purposes among young adolescents in ownership and use of smartphone applications (apps) and heart rate monitors (HRM). Methods: Young adolescents (N = 755; 11-, 13-, and 15-year-olds) in the Olomouc region of the Czech Republic were recruited t…
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…
How physical activity, fitness, and motor skills contribute to math performance: Working memory as a mediating factor
2021
Purpose The purpose of this study was to examine whether physical activity, fitness and motor skills have indirect association with math performance via cognitive outcomes and if so, through which aspects of cognition? Methods This study comprised 311 6th–9th grade adolescents (12–17y [M age=14.0y], 59% girls) from seven schools throughout Finland in 2015. Math performance was measured via a teacher-rated math achievement and the Basic Arithmetic test. Cognitive functions were measured by broad cognitive test battery. Physical activity was assessed with a self-reported questionnaire and a hip-worn accelerometer. Aerobic fitness was estimated using a maximal 20-m shuttle run test, muscular f…
The Influence of Solar Power Plants on Microclimatic Conditions and the Biotic Community in Chilean Desert Environments
2016
The renewable energy sector is growing at a rapid pace in northern Chile and the solar energy potential is one of the best worldwide. Therefore, many types of solar power plant facilities are being built to take advantage of this renewable energy resource. Solar energy is considered a clean source of energy, but there are potential environmental effects of solar technology, such as landscape fragmentation, extinction of local biota, microclimate changes, among others. To be able to minimize environmental impacts of solar power plants, it is important to know what kind of environmental conditions solar power plants create. This study provides information about abiotic and biotic conditions i…
Availability in BitTorrent Systems
2007
In this paper, we investigate the problem of highly available, massive-scale file distribution in the Internet. To this end, we conduct a large-scale measurement study of BitTorrent, a popular class of systems that use swarms of actively downloading peers to assist each other in file distribution. The first generation of BitTorrent systems used a central tracker to enable coordination among peers, resulting in low availability due to the tracker's single point of failure. Our study analyzes the prevalence and impact of two recent trends to improve BitTorrent availability: (i) use of multiple trackers, and (ii) use of Distributed Hash Tables (DHTs), both of which also help to balance load be…
The Quantified Athlete: Associations of Wearables for High School Athletes
2018
The adoption of wearable technology in competitive sports can be an advantage to performance and training. Athletes who use personalised data to quantify their performances with the possibilities of sharing with others may use wearables to reinforce the athletic identity. Despite these changes, few studies have actually examined the associations between wearables and developing athletes in their quest for professional sports. Student athletes (n = 437, age = 17y) still in high schools completed a web-based survey about their professional aspirations, athletic identity, and the association with wearables. Wearables were measured by ownership and usage of apps, fitness trackers, or sports wat…
Image registration for quality assessment of projection displays
2014
International audience; In the full reference metric based image quality assessment of projection displays, it is critical to achieve accurate and fully automatic image registration between the captured projection and its reference image in order to establish a subpixel level mapping. The preservation of geometrical order as well as the intensity and chromaticity relationships between two consecutive pixels must be maximized. The existing camera based image registration methods do not meet this requirement well. In this paper, we propose a markerless and view independent method to use an un-calibrated camera to perform the task. The proposed method including three main components: feature e…