187,330 research outputs found
Análise da indexação de imagens fotográficas em um banco de imagens comercial
No full textTCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências da Educação. Curso de Biblioteconomia.Analisa a indexação das fotografias que compõem um banco de imagens comercial. Realiza uma pesquisa exploratória, identificando o acervo fotográfico e reunindo os descritores de uma amostra de imagens. Compara por meio de uma pesquisa documental, os termos utilizados como descritores nas fotografias com a grade de análise de imagens fotográficas proposta por Manini (2002). Observa que a indexação realizada no acervo estudado condiz com quase todas as categorias propostas pela autora. Constata que a atribuição de descritores às imagens tem condições de contemplar todas as categorias propostas na grade de Manini (2002), mas que algumas das categorias podem ser contempladas em outros campos que não o de palavras-chave. Aponta a necessidade da existência de um profissional especializado no tratamento de imagens para a execução desta tarefa e que conheça tanto o tipo de cliente quanto os assuntos que as imagens possuem.Analyzes the indexing of photographs that compound a comercial image database. Performs an exploratory research, identifying the photographic collection and gathering the descriptors of a sample of images. Compares, through documentary research, the terms used as descriptors in the photographs with the method of analysis of fotograph images proposed by Manini (2002). Remarks that the indexing made in this collection is consistent with almost all categories proposed by the author. Observes that the attribution of descriptors to the images is able to cover all the categories proposed by Manini (2002). However, some other categories can be covered in other fields than the keyword field. Indicates the necessity of having one professional employee in image processing to perform this task, who is as aware of the different types of clients, as of the subjects of images in the collection
Liquid chromatography-particle beam-mass spectrometric determination of β-carotene by negative-ion chemical ionization
No full textTraffic Offloading/Onloading in Multi-RAT Cellular Networks
No full textWe analyze next generation cellular networks, offering connectivity to mobile users through multiple radio access technologies (RATs), namely LTE and WiFi. We develop a framework based on the Markovian agent formalism, which can model several aspects of the system, including user traffic dynamics and radio resource allocation. In particular, through a mean-field solution, we show the ability of our framework to capture the system behavior in flash-crowd scenarios, i.e., when a burst of traffic requests takes place in some parts of the network service area. We consider a distributed strategy for the user RAT selection, which aims at ensuring high user throughput, and investigate its performance under different resource allocation scheme
Sliding Mode Control for a Generalization of the Caginalp Phase-Field System
No full textIn the present paper, we present and solve the sliding mode control (SMC) problem for a second-order generalization of the Caginalp phase-field system. This generalization, inspired by the theories developed by Green and Naghdi on one side, and Podio-Guidugli on the other, deals with the concept of thermal displacement, i.e., a primitive with respect to the time of the temperature. Two control laws are considered: the former forces the solution to reach a sliding manifold described by a linear constraint between the temperature and the phase variable; the latter forces the phase variable to reach a prescribed distribution φ∗. We prove existence, uniqueness as well as continuous dependence of the solutions for both problems; two regularity results are also given. We also prove that, under suitable conditions, the solutions reach the sliding manifold within finite time
Il ruolo delle educatrici nei servizi per l'infanzia.
No full textIl saggio affronta le caratteristiche comuni e quelle differenti del ruolo delle educatrici negli asili nido e nelle nuove tipologie. Segue l'analisi degli elementi problematici per quanto concerne il rapporto tra professionalità agita e formazione di base ed inoltre rispetto al ruolo delle educatrici in un'ottica di continuità all'interno di un sistema educativo multicentrico
Jahn-Teller spectral fingerprint in molecular photoemission : C-60
No full textThe h(u) hole spectral intensity for C-60-->C-60(+) molecular photoemission is calculated at finite temperature by a parameter-free Lanczos diagonalization of the electron-vibration Hamiltonian, including the full 8 H-g, 6 G(g), and 2 A(g) mode couplings. The computed spectrum at 800 K is in striking agreement with gas-phase data. The energy separation of the first main shoulder from the main photoemission peak, 230 meV in C-60, is shown to measure directly and rather generally the strength of the final-state Jahn-Teller coupling
El Rey de Sierra-Morena : aventuras del famoso ladron José María
No full textContiene: Vol. I. (568 p., [13] h. de lám.) -- vol. II. (568, [11] h. de lám.) -- vol. III. (568 p., [8] h. de lám.) vol. IV. (575 p., [11] h. de lám.) -- vol. V. (864 p., [14] h. de lám.
Oxidation chemistry of catecholamines and neuronal degeneration: an update.
No full textA review. Aberrant oxidative pathways of catecholamine neurotransmitters, i.e. dopamine and norepinephrine, are an important biochem. correlate of catecholaminergic neuron loss in some disabling neurodegenerative diseases of the elderly, notably Parkinson's disease. In an oxidative stress setting, under conditions of elevated lipid peroxidn., iron accumulation, impaired mitochondrial functioning and antioxidant depletion, catecholamines are oxidatively converted to the corresponding o-quinones, which may initiate a cascade of spontaneous reactions, including intramol. cyclization, aminoethyl side chain fission and interaction with mol. targets. The overall outcome of the competing pathways may vary depending on contingent factors and the biochem. environment, and may include formation of nitrated derivs., neuromelanin deposition, generation of chain fission products, conjugation with L-Cys leading eventually to cytotoxic responses and altered cellular function. In addn., catecholamines may interact with products of lipid peroxidn. and other species derived from oxidative breakdown of biomols., notably glyoxal and other aldehydes, leading e.g. to tetrahydroisoquinolines via Pictet-Spengler chem. After a brief introductory remark on oxidative stress biochem., the bulk of this review will deal with an overview of the basic chem. pathways of catecholamine oxidn., with special emphasis on the analogies and differences between the central neurotransmitters dopamine and norepinephrine. This chem. will form the basis for a concise discussion of the latest advances in the mechanisms of catecholamine-assocd. neurotoxicity in neuronal degeneration
Berry phase and ground-state symmetry in H circle times h dynamical Jahn-Teller systems
No full textDue to the ubiquitous presence of a Berry phase, in most cases of dynamical Jahn-Teller systems the symmetry of the vibronic ground state is the same as that of the original degenerate electronic state; As a single exception, the linear H x h icosahedral model is determined by an additional free parameter, which can be continuously tuned to eliminate the Berry phase from the low-energy closed paths: accordingly, the ground state changes to a totally symmetric nondegenerate state. The detailed values of the parameters not being known, the issue of the actual ground-state symmetry of C-60(+) is open.LB
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