Search results for "trajectory."
showing 10 items of 201 documents
A New Small Drifter for Shallow Water Basins: Application to the Study of Surface Currents in the Muggia Bay (Italy)
2016
A new small drifter prototype for measuring current immediately below the free surface in a water basin is proposed in this paper. The drifter dimensions make it useful for shallow water applications. The drifter transmits its GPS location via GSM phone network. The drifter was used to study the trajectory of the surface current in the Muggia bay, the latter containing the industrial harbor of the city of Trieste (Italy). The analysis has been carried out under a wide variety of wind conditions. As regards the behavior of the drifter, the analysis has shown that it is well suited to detect the water current since its motion is marginally affected by the wind. The study has allowed detecting…
Parametric uncertainty or hydrological changes?
2014
Abstract. The model calibration is the way of hydrologists for searching also a physical interpretation of complex interactions acting within a basin. Actually, it can be frequently noticed how model calibration performed on a given time-window may converge to a point in the parameter space that could be distant from another obtainable calibration of the model in the same basin but considering a different time window. Is that again parametric uncertainty or does the trajectory in the parametric space relate about to a slow hydrological basin change? This paper depicts a possible path for detecting changes' signatures in a streamflow time series. In particular, the paper seeks to draw a way …
Meeting the Challenges of High-Dimensional Single-Cell Data Analysis in Immunology
2019
Recent advances in cytometry have radically altered the fate of single-cell proteomics by allowing a more accurate understanding of complex biological systems. Mass cytometry (CyTOF) provides simultaneous single-cell measurements that are crucial to understand cellular heterogeneity and identify novel cellular subsets. High-dimensional CyTOF data were traditionally analyzed by gating on bivariate dot plots, which are not only laborious given the quadratic increase of complexity with dimension but are also biased through manual gating. This review aims to discuss the impact of new analysis techniques for in-depths insights into the dynamics of immune regulation obtained from static snapshot …
Cavezzo, the first Italian meteorite recovered by the PRISMA fireball network. Orbit, trajectory, and strewn-field
2020
ABSTRACT Two meteorite pieces have been recovered in Italy, near the town of Cavezzo (Modena), on 2020 January 4th. The associated fireball was observed on the evening of New Year’s Day 2020 by eight all-sky cameras of the PRISMA fireball network, a partner of FRIPON. The computed trajectory had an inclination angle of approximately 68° and a velocity at infinity of 12.8 km s−1. Together with the relatively low terminal height, estimated as 21.5 km, those values were indicating the significant possibility of a meteorite dropping event, as additionally confirmed by the non-zero residual total mass. The strewn-field was computed taking into account the presence of two bright light flashes, re…
Trajectory subgroups of perceived emotional support from teachers : Associations with change in mastery climate and intentions to quit upper secondar…
2022
The aims of this three-wave longitudinal study were to identify and describe trajectories of perceived emotional support from teachers and investigate whether these trajectories were related to the development of intentions to quit upper secondary school via change in perceived mastery climate. Among 1379 Norwegian upper secondary school students, three trajectory subgroups were identified: stable high (84.9%), decreasing (7.8%), and low increasing (7.3%). The subgroups differed in levels of achievement ambition and academic self-concept. Further, a parallel process latent growth curve model revealed essential associations with change in intentions to quit school. Specifically, students wit…
Collision Avoidance with Potential Fields Based on Parallel Processing of 3D-Point Cloud Data on the GPU
2014
In this paper we present an experimental study on real-time collision avoidance with potential fields that are based on 3D point cloud data and processed on the Graphics Processing Unit (GPU). The virtual forces from the potential fields serve two purposes. First, they are used for changing the reference trajectory. Second they are projected to and applied on torque control level for generating according nullspace behavior together with a Cartesian impedance main control loop. The GPU algorithm creates a map representation that is quickly accessible. In addition, outliers and the robot structure are efficiently removed from the data, and the resolution of the representation can be easily ad…
Jacobi Fields, Conjugate Points
2001
Let us go back to the action principle as realized by Jacobi, i.e., time is eliminated, so we are dealing with the space trajectory of a particle. In particular, we want to investigate the conditions under which a path is a minimum of the action and those under which it is merely an extremum. For illustrative purposes we consider a particle in two-dimensional real space.
Optimal control of the Schrödinger equation with two or three levels
2007
In this paper, we present how techniques of “control theory”, “sub-Riemannian geometry” and “singular Riemannian geometry” can be applied to some classical problems of quantum mechanics and yield improvements to some previous results.
Praca nad własną biografią matek dzieci z niepełnosprawnością na przykładzie projektu pt. „Siła kobiet”
2021
W artykule opisany został projekt edukacyjno-socjalny pt. ,,Siła kobiet", skierowany do matek dzieci z niepełnosprawnością. Projekt miał tez charakter naukowo-badawczy, którego nadrzędnym celem było poznanie procesu uczenia się z biografii. Intencją autorki było zaprezentowanie działań realizowanych podczas projektu, które miały umożliwić jego uczestniczkom zaobserwowanie procesu uczenia się z własnej biografii w kontekście niepełnosprawności swojego dziecka. W pierwszej części artykułu zamieszczony został teoretyczno-metodologiczny opis projektu i jego metodyczne podstawy. W części analitycznej zaprezentowane zostały fragmenty transkrypcji w odniesieniu do teorii uczenia się sytuacyjnego i…
Adaptive Control of Underactuated Underwater Vehicles
2008
This paper deals with a control strategy for underactuated underwater vehicles whose target is trajectory tracking. A cascade approach is employed which brings to a control law consisting of: a) an outer loop, obtained from the vehicle kinematic model, which forces this model to track the reference trajectory; b) an inner adaptive control loop which forces the system to track the reference signals given by the outer control loop. Conditions for asymptotic tracking of the trajectory and boundness of the unactuated velocities are given. Simulation tests illustrate the proposed approach.