Search results for "video"
showing 10 items of 1348 documents
Abrupt-tapered fiber filter arrangement for a switchable multi-wavelength and tunable Tm-doped fiber laser.
2018
A switchable and tunable multi-wavelength Tm-doped fiber laser is successfully demonstrated using a filter constructed with two tapered fiber elements in the cavity. The proposed system design uses a low-cost simple filter that allows stable dual, triple, quadruple, and quintuple-wavelength emission operation in the region around 1.9 μm. In the dual wavelength regime, the laser is capable of independently tuning each wavelength. For switching and tuning, a curvature is applied to the tapered fibers.
Wide wavelength-tunable passive mode-locked Erbium-doped fiber laser with a SESAM
2021
Abstract In this work we present a simple polarization-maintaining wavelength-tunable passive mode-locked Erbium-doped fiber laser with a semiconductor saturable absorber mirror (SESAM) as a mode locker. The cavity includes a Sagnac interferometer-based fiber optical loop mirror (FOLM) as a wide wavelength-tunable filter. Tunable mode-locking was experimentally achieved in the range of 1543.2 nm to 1569.5 nm by thermally adjustment of FOLM wavelength reflection. The output pulses have a repetition rate of 11.16 MHz with pulse duration about 0.9 ps. The experimental results were confirmed by numerical simulations.
Learning for allocations in the long-run average core of dynamical cooperative TU games
2011
We consider repeated coalitional TU games characterized by unknown but bounded and time-varying coalitions' values. We build upon the assumption that the Game Designer uses a vague measure of the extra reward that each coalition has received up to the current time to learn on how to re-adjust the allocations among the players. As main result, we present an allocation rule based on the extra reward variable that converges with probability one to the core of the long-run average game. Analogies with stochastic stability theory are put in evidence.
Dealing with uncertainty in consensus protocols
2009
Recent results on consensus protocols for networks are presented. The basic tools and the main contribution available in the literature are considered, together with some of the related challenging aspects: estimation in networks and how to deal with disturbances is considered. Motivated by applications to sensor, peer-to-peer, and ad hoc networks, many papers have considered the problem of estimation in a consensus fashion. Here, the Unknown But Bounded (UBB) noise affecting the network is addressed in details. Because of the presence of UBB disturbances convergence to equilibria with all equal components is, in general, not possible. The solution of the e-consensus problem, where the stat…
LAS TECNOLOGÍAS DE LA INFORMACIÓN Y COMUNICACIÓN EN LA EDUCACIÓN LATINOAMERICANA: MODELOS Y TENDENCIAS DE USO (Information and Communication Technolo…
2021
Spanish abstract: Resumen: La iniciativa para la elaboracion de un libro resultados de investigacion, nace de una reflexion realizada por un grupo de docentes investigadores de Latinoamerica y America Central, con el proposito de producir una obra en formato digital, para la socializacion de proyectos de investigacion y los resultados de estos. Por lo anterior, se propuso lineas tematicas vinculadas en la docencia y la brecha tecnologica, servicios empresariales con TIC, la gamificacion con uso de apps y plataformas educativas libres en el aula, modernizacion de procesos empresariales y agronomia uso en el sector agrario con TIC. Se presentan resultados investigativos variados, desde el pro…
A comparative study on the phase behaviour of highly charged colloidal spheres in a confining wedge geometry
2005
We studied the structures formed in aqueous dispersions of charged colloidal spheres under a constant low salt concentration of c = 6 × 10−6 mol l−1. Particles of diameter 2a = 1000 nm were confined to a low angle wedge geometry with plate separation 0<S<50 µm and observed with video microscopy. Irrespective of the initial particle density n we reproducibly observe the particles to migrate to the narrow wedge side on the timescale of a few days. Thereby an interface between a crystalline structure and a near particle free region is formed, which propagates slowly until the dilute region is exhausted of particles. While the origin of this separation is still unclear, the final extension of t…
Does Replacing Face-to-face Lectures with Pre-recorded Video Lectures Affect Learning Outcomes?
2019
Videoing lectures have been popular during the past decade. The literature on the effect of video lectures is controversial. Some studies indicate that video lectures have a positive effect on learning outcomes and student satisfaction, while some state that there is no effect at all. In this paper, we share the results of a university undergraduate course, where half of the lectures were replaced by pre-recorded lectures. The results indicate that using pre-recorded lectures had a statistically significant positive effect on grades. Also, the students’ satisfaction levels were higher. peerReviewed
A block access unit for 2D memory access
2007
Many of the coding tools in the H.264/AVC video coding standard are based on 2D processing resulting in rowwise and column-wise memory accesses starting from arbitrary memory addresses. This paper discusses a low-cost hardware realization of these accesses on sub-word parallel processors. The proposed block access unit is placed between the processor and memory. It supports unaligned 2D block accesses according to several 2D access patterns. The 2D block accesses are pipelinable and they result in minimum number of memory accesses required to deliver the desired data.
Orientational dynamics of fluctuating dipolar particles assembled in a mesoscopic colloidal ribbon
2017
We combine experiments and theory to investigate the dynamics and orientational fluctuations of ferromagnetic microellipsoids that form a ribbonlike structure due to attractive dipolar forces. When assembled in the ribbon, the ellipsoids display orientational thermal fluctuations with an amplitude that can be controlled via application of an in-plane magnetic field. We use video microscopy to investigate the orientational dynamics in real time and space. Theoretical arguments are used to derive an analytical expression that describes how the distribution of the different angular configurations depends on the strength of the applied field. The experimental data are in good agreement with the…
Robust Depth Estimation for Light Field Microscopy
2019
Light field technologies have seen a rise in recent years and microscopy is a field where such technology has had a deep impact. The possibility to provide spatial and angular information at the same time and in a single shot brings several advantages and allows for new applications. A common goal in these applications is the calculation of a depth map to reconstruct the three-dimensional geometry of the scene. Many approaches are applicable, but most of them cannot achieve high accuracy because of the nature of such images: biological samples are usually poor in features and do not exhibit sharp colors like natural scene. Due to such conditions, standard approaches result in noisy depth ma…