Sunday, October 26, 2014

 

 



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rss_1.0 Clasificación por Disciplina

Nomenclatura Unesco > (22) Física > (2203) Electrónica
(2203.01) Circuitos (2203.02) Elementos de circuitos
(2203.03) Válvulas electrónicas (2203.04) Microscopía electrónica
(2203.05) Estados electrónicos (2203.06) Transporte de electrones
(2203.07) Circuitos integrados (2203.08) Fotoelectricidad
(2203.09) Piezoelectricidad (2203.99) Otras (especificar)

Categorías relacionadas:
(3307) Tecnología electrónica

Mostrando recursos 1 - 20 de 239,406

1. Impactos percebidos da contratação Pública electrónica: O caso das PME da construção civil do norte de Portugal - Vítor Vieira

2. A Context-based Institutional Normative Environment - Eugénio Oliveira; Henrique Lopes Cardoso
We explore the concept of an agent-based Electronic Institution including a normative environment that supports electronic contract formation by providing a contextual normative background. We formalize the normative state using first-order logic and define institutional rules and norms operating on that state. A suitable semantics regarding the use of norms within a hierarchical context structure is given, based on norm activation conflict and defeasibility. Norm activation relies on substitution as in first-order logic. Reasoning about the fulfillment and violation of deadline obligations is formalized using linear temporal logic; implementation with institutional rules is discussed. Examples exploiting the normative environment are...

3. Proceedings of the 2014 Workshop on Intelligent Agents and Technologies for Socially Interconnected Systems
IAT4SIS workshop will provide a space for the discussion on Artificial Intelligence driven concepts and recent developments on Agent-based techniques dealing with interoperability issues in socially interconnected systems. These issues mainly refer to complementary perspectives on interaction, coordination, negotiation, regulation and trust.A wide variety of electronic business scenarios and systems, including enterprises networking, as well as agent-based approaches to this subject, have been proposed in recent years. The primary goal of this workshop is to bring together the most recent and innovative scientific research from a diversity of fields as Computer Science, Artificial Intelligence and Distributed Systems that focus on...

4. A Multi-Agent System for Electronic Commerce including Adaptive Strategic Behaviours - Eugénio Oliveira; Henrique Lopes Cardoso; Max Schaefer

5. Recensão de: Diccionario Bilingüe de Uso: español portugués / português espanhol, Francisco Moreno e Neide Maia González (dirs.), Madrid, Arco/Libros, 2003, 2 vols., Primeira Prova. Revista electrónica de línguas e literaturas, 0. Edição electrónica: http://www.letras.up.pt/deper/primeiraprova/default.htm - Rogelio Ponce de León Romeo

6. Open Access in the humanities - Eve, Martin Paul
A presentation to the ICOLC.

7. Open Access journals in the humanities - Eve, Martin Paul
Includes talks from MMU Professor Cathy Urquhart, Dr. Frances Pinter (Manchester University Press) and Dr. Martin Eve (Open Library of Humanities) as well as a “tradeshow” with representatives from Open Access publishers

8. Open Access and the Open Library of Humanities - Eve, Martin Paul
Dr Martin Eve (Lecturer in English, University of Lincoln and OLH Co-Founder). OLH’s vision is ‘building a low cost, sustainable, Open Access future for the humanities’. Find out what’s happening and how to get involved. Martin is on the JISC OAPEN-UK project committee, chief editor of open access journal Orbit, and writes about Open Access for the Guardian Higher Education Network.

9. Multidimensional blocking in UPC - Barton, Christopher; Cascaval, Calin; Almási, George; Garg, Rahul; Amaral, José Nelson; Farreras Esclusa, Montserrat
Partitioned Global Address Space (PGAS) languages offer an attractive, high-productivity programming model for programming large-scale parallel machines. PGAS languages, such as Unified Parallel C (UPC), combine the simplicity of shared-memory programming with the efficiency of the message-passing paradigm by allowing users control over the data layout. PGAS languages distinguish between private, shared-local, and shared-remote memory, with shared-remote accesses typically much more expensive than shared-local and private accesses, especially on distributed memory machines where shared-remote access implies communication over a network. In this paper we present a simple extension to the UPC language that allows the programmer to block shared arrays in...

10. Optimum CSPR evaluation of heterodyne envelope receivers in OFDM-PONs - Behnam Shariati, Mohammad; Cano Valadéz, Iván Nicolás; Santos Blanco, M. Concepción
A heterodyne envelope (HE) receiver (RX) is investigated in the context of orthogonal frequency division multiplexing (OFDM) passive optical networks (PONs). Impacts of limited roll-off factor of shaping filter and required guard-band (GB) are studied through numerical simulations, showing that the Carrier to Signal Power Ratio (CSPR) value plays a significant role in the systems performance. For a QPSK system with 10 Gbps bitrate and for a bit error ratio (BER) quality threshold of 10-3 we show an improvement of 10.8 dB in sensitivity and 25% in spectral efficiency by using an optimum CSPR value as compared to unity CSPR.

11. Direct phase modulation of a DFB laser for udWDM-PON - Cano Valadéz, Iván Nicolás; Lerin De La Santisima Trinidad, Adolfo; Polo Querol, Víctor; Prat Gomà, Josep Joan
The response of a DFB was equalized with a simple RC network for modulating directly its phase and producing a BPSK signal. The system was tested with a heterodyne coherent detector at 1.25 Gb/s and 2.5 Gb/s showing a sensitivity penalty of around 1dB when compared with external phase modulation. The results indicate that the technique could be considered as a reliable low-cost ONU transmitter solution in udWDM-PONs.

12. Finding Beneficial DAE Structures in Circuit Simulation - Diana Estévez Schwarz; Uwe Feldmann; Roswitha März; Sandra Sturtzel; Caren Tischendorf
Circuit simulation is a standard task for the computer-aided design of electronic circuits. The transient analysis is well understood and realized in powerful simulation packages for conventional circuits. But further developments in the production engineering lead to new classes of circuits which may cause difficulties for the numerical integration. The dimension of circuit models can be quite large (10⁵ equations). The complexity of the models demands a higher abstraction level. In this paper, we analyze electric circuits with respect to their structural properties. We discuss the relevant subspaces of the resulting differential algebraic equations (DAEs) and present algorithms for calculating...

13. PORTAFOLIO DE INVERSIÓN EN ACCIONES OPTIMIZADO. - Sánchez Castro, John Jairo; Restrepo, Jorge Hernán; Cruz Trejos, Eduardo Arturo
This document presents a method to make optimal investments on instruments of Variable Income, like shares, using the Variance- Covariance procedure in the mathematical model of quadratic programming, developed in an Excel electronic sheet, in order to determine the efficient boundary of the investment portfolio. Subsequently, the optimum point of the established set is evaluated through the criteria of the lossing possibility.

14. Chemistry, nanostructure and magnetic properties of Co-Ru-B-O nanoalloys - Arzac, Gisela M.; Rojas, T. Cristina; Gontard, Lionel C.; Chinchilla, Lidia E.; Otalora, E.; Crespo, P.; Fernández-Camacho, A.
© the Partner Organisations 2014. In our previous works, Co-B-O and Co-Ru-B-O ultrafine powders with variable Ru content (xRu) were studied as catalysts for hydrogen generation through sodium borohydride hydrolysis. These materials have shown a complex nanostructure in which small Co-Ru metallic nanoparticles are embedded in an amorphous matrix formed by Co-Ru-B-O based phases and B2O3. Catalytic activity was correlated to nanostructure, surface and bulk composition. However, some questions related to these materials remain unanswered and are studied in this work. Aspects such as: 3D morphology, metal nanoparticle size, chemical and electronic information on the nanoscale (composition and oxidation states),...

15. Descomposición térmica de residuos de aparatos eléctricos y electrónicos: estudio cinético y formación de contaminantes - Ortuño García, Nuria

16. Reparto transversal de la sobrecarga en tableros de puentes - Samartín, Avelino; Martínez González, Jesús
Se presenta el cálculo de esfuerzos de una losa ortótropa rectangular apoyada en dos bordes opuestos y en los otros dos con condiciones de contorno muy generales. La formulación se realiza en forma compacta al utilizar la notación matricial, lo que permite una programación directa en un computador electrónico. La solución obtenida se compara con la que se deduce mediante el método de Guyon-Massonet-Rowe, que constituye una simplificación muy conocida, y se comentan las diferencias existentes. Se muestra a continuación un estudio alternativo mediante la teoría de láminas plegadas prismáticas, que representa un modelo matemático más adecuado para este tipode...

17. Seminário de Investigação em Museologia dos Países de Língua Portuguesa e Espanhola [recurso electrónico]

18. Tecnologias da comunicação e informação - Rocio, Vitor
A utilização das Tecnologias de Informação e Comunicação (TIC) é cada vez mais um imperativo na sociedade actual. Saber utilizar um computador, elaborar um documento electrónico, consultar informação na Internet são cada vez mais competências indispensáveis em qualquer actividade humana. Por detrás das funcionalidades que nos permitem realizar estas tarefas, está um conjunto de princípios e tecnologias que importa conhecer e compreender, mesmo que de uma forma superficial, por forma a usá-las mais eficazmente e para podermos tomar decisões informadas relativamente à aplicação das mesmas nas actividades mais variadas. Este curso é dirigido a não especialistas em Informática que pretendam ter...

19. Open Access: where are we now? - Priego, Ernesto; Edwards, Caroline; Tennant, Jon; Eve, Martin Paul; Ainsworth, Anne-Marie; Lawson, Stuart; McArthur, Joe
A panel at City University London on open access.

20. Estimating the Harms of Nicotine-Containing Products Using the MCDA Approach - Nutt, DJ; Phillips, LD; Balfour, D; Curran, HV; Dockrell, M; Foulds, J; Fagerstrom, K; Letlape, K; Milton, A; Polosa, R; Ramsey, J; Sweanor, D

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