Search results for "TRACKING"

Meta-Tracking for Video Scene Understanding

2013

International audience; This paper presents a novel method to extract dominant motion patterns (MPs) and the main entry/exit areas from a surveillance video. The method first computes motion histograms for each pixel and then converts it into orientation distribution functions (ODFs). Given these ODFs, a novel particle meta-tracking procedure is launched which produces meta-tracks, i.e. particle trajectories. As opposed to conventional tracking which focuses on individual moving objects, meta-tracking uses particles to follow the dominant flow of the traffic. In a last step, a novel method is used to simultaneously identify the main entry/exit areas and recover the predominant MPs. The meta…

Slewing mirror telescope of the UFFO-pathfinder: first report on performance in space

2017

To observe the early optical emissions from gamma ray bursts (GRBs), we built the Slew Mirror Telescope. It utilizes a 150 mm motorized mirror to redirect incoming photons from astrophysical objects within seconds and to track them as compensating satellite movements. The SMT is a major component of the UFFO-pathfinder payload, which was launched on April 28, 2016, onboard the Lomonosov satellite. For the first time, the slewing mirror system has been proven for the precision tracking of astrophysical objects during space operation. We confirmed that the SMT has 1.4 seconds of response time to the X-gamma-ray trigger, and is able to compensate for satellite drift and to track astrophysical …

Selezione di Portafoglio e Metaeuristiche

2013

Il problema della selezione del portafoglio (PSP) ha come obiettivo quello di determinare, disponendo di un dato insieme di titoli, il portafoglio che minimizza una misura di rischio per un dato livello di rendimento minimo richiesto. Sebbene nella sua formulazione originaria il PSP può essere risolto utilizzando algoritmi di programmazione lineare o quadratica, l'inclusione di ulteriori vincoli ed obiettivi rende il problema computazionalmente difficile. Nel presente lavoro viene proposto un approccio metaeuristico al PSP in cui vengono considerate diverse misure di distanza tra i portafogli della frontiera efficiente (Mean-Variance) ed il portafoglio ottimo che si ottiene in corrispondenz…

Power management of grid-connected photovoltaic inverter with storage battery

2011

With increased penetration of PV generation in the power grid, it becomes necessary to control the PV generation similar to the conventional power sources. Grid-connected PV systems equipped with storage batteries are capable of active power control. PV power generation can be either fed into the grid or stored in the battery. This paper presents a deterministic power management algorithm that uses closed-form approximations derived from analytical loss models. It can be configured to maximize the efficiency or the revenue in a liberalized electricity market. The battery controller emulates an optimum load-line in which the PV power is autonomously shared between the battery and the feed-in…

Hydrogen back-up power system with photovoltaic direct energy transfer regulation and interleaved boost for space applicattions

2012

This work details a power conditioning unit for photovoltaic/hydrogen based energy systems in space applications. The power conversion techniques applied are similar to the ones used on photovoltaic/battery space power systems. A direct energy transfer photovoltaic regulator is devised for feeding two outputs; the first output corresponds to the main unregulated battery bus and the second output sets a power path to feed an electrolyser. A modular fuel cell converter completes the system and operates when photovoltaic energy is not available or load demand exceeds the generated photovoltaic power, providing electrical power from a fuel cell. An ancillary battery, located in the main bus, di…

Design of a solar-battery-thermoelectric power converter prototype

2015

In this paper a multisource renewable energy system for high-current applications is proposed. The power architecture is based on a multi-input power converter including control and reconfiguration subsystems. Independently of the type of connected renewable sources, a proper control of the output DC voltage bus is provided as well as a proper control on the operating point of each renewable source to achieve the maximum power transfer. A 48V thermoelectric-photovoltaic-battery system in a three input configuration is designed. Three interacting feedback networks are implemented: the outer loop which controls the output voltage and as many inner loops as connected renewable sources to achie…

Performance evaluation of a multisource renewable power converter prototype

2014

On the influence of context-based complexity on information search patterns: An individual perspective

2014

Although context-based complexity measured as the similarity and conflict across alternatives is dependent on individual preference structures, existing studies investigating the influence of context-based complexity on information search patterns have largely ignored that context-based complexity is user- and preference-dependent. Addressing this research gap, this article elicits the individual preferences of decision makers by using the pairwise-comparison-based preference measurement (PCPM) technique and records individuals' search patterns using eye tracking. Our results show that an increased context-based complexity leads to an increase in information acquisition and the use of a mor…

The Influence of Context-Based Complexity on Decision Processes

2011

In this chapter, we present an empirical study which investigates the influence of context-based complexity on decision processes.1 To determine context-based complexity accurately, we measure each subject’s preferences individually with two advanced techniques from marketing research: choice-based conjoint analysis (CBC, Haaijer and Wedel 2007) and pairwise-comparison-based preference measurement (PCPM, Scholz et al. 2010), rather than relying on less precise estimates of preferences. Furthermore, we use eye tracking to trace the process of information acquisition precisely. Our results show that low context-based complexity leads to less information acquisition and more alternative-wise s…

Measurement of visible cross sections in proton-lead collisions at √sNN= 5.02 TeV in van der Meer scans with the ALICE detector

2014

In 2013, the Large Hadron Collider provided proton-lead and lead-proton collisions at the center-of-mass energy per nucleon pair $\sqrt{s_{\rm{NN}}}=5.02$ TeV. Van der Meer scans were performed for both configurations of colliding beams, and the cross section was measured for two reference processes, based on particle detection by the T0 and V0 detectors, with pseudo-rapidity coverage $4.6<\eta< 4.9$, $-3.3<\eta<-3.0$ and $2.8<\eta< 5.1$, $-3.7<\eta<-1.7$, respectively. Given the asymmetric detector acceptance, the cross section was measured separately for the two configurations. The measured visible cross sections are used to calculate the integrated luminosity of the proton-lead and lead-…