Performance Analysis of Project-and-Forward Relaying in Mixed MIMO-Pinhole and Rayleigh Dual-Hop Channel

In this letter, we present an end-to-end performance analysis of dual-hop project-and-forward relaying in a realistic scenario, where the source-relay and the relay-destination links are experiencing MIMO-pinhole and Rayleigh channel conditions, respectively. We derive the probability density function of both the relay post-processing and the end-to-end signal-to-noise ratios, and the obtained expressions are used to derive the outage probability of the analyzed system as well as its end-to-end ergodic capacity in terms of generalized functions. Applying then the residue theory to Mellin-Barnes integrals, we infer the system asymptotic behavior for different channel parameters. As the bivariate Meijer-G function is involved in the analysis, we propose a new and fast MATLAB implementation enabling an automated definition of the complex integration contour. Extensive Monte-Carlo simulations are invoked to corroborate the analytical results.Comment: 4 pages, IEEE Communications Letters, 201

A mixed FEM for a time-fractional Fokker-Planck model

We propose and analyze a mixed finite element method for the spatial approximation of a time-fractional Fokker--Planck equation in a convex polyhedral domain, where the given driving force is a function of space. Taking into account the limited smoothing properties of the model, and considering an appropriate splitting of the errors, we employed a sequence of clever energy arguments to show optimal convergence rates with respect to both approximation properties and regularity results. In particular, error bounds for both primary and secondary variables are derived in $L^2$-norm for cases with smooth and nonsmooth initial data. We further investigate a fully implicit time-stepping scheme based on a convolution quadrature in time generated by the backward Euler method. Our main result provides pointwise-in-time optimal $L^2$-error estimates for the primary variable. Numerical examples are then presented to illustrate the theoretical contributions

Signal-Level Cooperative Spatial Multiplexing for Uplink Throughput Enhancement in MIMO Broadband Systems

International audienceIn this paper, we address the issue of throughputefficient half-duplex constrained relaying schemes for broadband uplink transmissions over multiple-input multiple-output (MIMO) channels. We introduce a low complexity signal-level cooperative spatial multiplexing (CM) architecture that allows for the shortening of the relaying phase without resorting to any symbol detection or re-mapping at the relay side. Half-duplex latency is thereby reduced, resulting in a remarkable throughput gain compared to amplify-and-forward (AF) relaying scheme. Surprisingly, we show that CM strategy becomes more powerful in boosting uplink throughput as the relay approaches cell edge

VOZES DE INTELECTUAIS DA EDUCAÇÃO EM OPOSIÇÃO À CRIAÇÃO DO ENSINO MUNICIPAL PAULISTANO (1956)

O artigo apresenta a criação do ensino primário municipal paulistano, em 1956, e as vozes de intelectuais da educação que, utilizando elementos técnicos, desenvolveram um posicionamento político contrário a nova oferta de ensino na cidade de São Paulo. Neste momento histórico, o ensino municipal iria polarizar com as escolas estaduais, tendo parte da imprensa, em especial o jornal O Estado de S. Paulo, e núcleos intelectuais se posicionado contrários a municipalização proposta então pelo prefeito Wladimir de Toledo Piza. Evidencia-se que as estratégias e discursos na publicação objetivariam desenvolver uma oposição partidária aos chefes do executivo municipais que buscariam empreender a nova modalidade de ensino, tornando parcial o tipo de jornalismo praticado sobre a municipalização. Educadores renomados como Antonio de Almeida Jr. e Carlos Correa Mascaro foram importantes vozes de oposição em seus livros publicados no período de criação do ensino municipal na cidade de São Paulo. A análise retrata os argumentos dos autores e o contexto histórico apontado no posicionamento. Mascaro (1960), em especial, seria a partir da publicação de suas obras sobre o tema, utilizado como referencial para a História do Ensino Municipal Paulistano. Ponderamos que o autor era um sujeito atuante na causa, tendo uma visão que o próprio revisaria anos depois.

Tectonosedimentary evidence in the Tunisian Atlas, Bou Arada Trough: insights for the geodynamic evolution and Africa-Eurasia plate convergence

International audienceThe Bou Arada Trough is an east-west-oriented structure located 80 km SW of Tunis, characterizing the central Tunisian Atlas. This trough is filled by a thick Quaternary sand and clay series and is bordered by complex systems of folds generally trending NE-SW. Contacts between the Bou Arada Trough and the neighbouring folds are accommodated by NE-SW- and NW-SE-oriented faults. In contrast to the other troughs of the Tunisian Atlas, which are related to the Pliocene-Quaternary orogenic period, the geodynamic evolution of the Bou Arada Trough began in the Maastrichtian and has continued until the present day. Structural, tectonosedimentary and seismic data analyses are undertaken in the study area to better understand the evolutionary scenario of this trough. The results obtained show that the Bou Arada Trough is fragmented into three NW-SE-oriented sub-basins and records a continuous history of downthrow. Indeed, during extensional to transtensional regimes, this trough has evolved in response to the two networks of perpendicular fractures whereas during compressive to transpressive periods, the collapse of the Bou Arada Trough has been induced by a pull-apart mechanism using the same network of faults but with a strike-slip movement. The Bou Arada Trough thus preserves a record of the convergence between the European and African plates since the Maastrichtian

Positive end-expiratory pressure affects the value of intra-abdominal pressure in acute lung injury/acute respiratory distress syndrome patients: a pilot study

International audienceIntroduction: To examine the effects of positive end-expiratory pressure (PEEP) on intra-abdominal pressure (IAP) in patients with acute lung injury (ALI).Methods: Thirty sedated and mechanically ventilated patients with ALI or acute respiratory distress syndrome (ARDS) admitted to a sixteen-bed surgical medical ICU were included. All patients were studied with sequentially increasing PEEP (0, 6 and 12 cmH2O) during a PEEP-trial.Results: Age was 55 ± 17 years, weight was 70 ± 17 kg, SAPS II was 44 ± 14 and PaO2/FIO2 was 192 ± 53 mmHg. The IAP was 12 ± 5 mmHg at PEEP 0 (zero end-expiratory pressure, ZEEP), 13 ± 5 mmHg at PEEP 6 and 15 ± 6 mmHg at PEEP 12 (P < 0.05 vs ZEEP). In the patients with intra-abdominal hypertension defined as IAP ≥ 12 mmHg (n = 15), IAP significantly increased from 15 ± 3 mmHg at ZEEP to 20 ± 3 mmHg at PEEP 12 (P < 0.01). Whereas in the patients with IAP < 12 mmHg (n = 15), IAP did not significantly change from ZEEP to PEEP 12(8 ± 2 vs 10 ± 3 mmHg). In the 13 patients in whom cardiac output was measured, increase in PEEP from 0 to 12 cmH2O did not significantly change cardiac output, nor in the 8 out of 15 patients of the high-IAP group. The observed effects were similar in both ALI (n = 17) and ARDS (n = 13) patients.Conclusions: PEEP is a contributing factor that impacts IAP values. It seems necessary to take into account the level of PEEP whilst interpreting IAP values in patients under mechanical ventilation

Application of unsupervised support vector machine for condition assessment of concrete structures

This paper presents research work that aims at developing a robust method for condition assessment of real-life concrete structures for the detection of small cracks at an early stage of development. A method is presented that utilises an unsupervised one-class support vector machine (SVM).Measured acceleration data from the current state of a structure are used as input parameter. The first singular value of the measured response data is utilized for training and testing of new data sets. Two damage identification approaches are demonstrated, one implementing the SVM for each measurement sensor separately, and another one implementing the SVM for all sensors combined. The use of one-class SVM is well suited for the condition assessment in structural health monitoring since they can detect the advancement of cracks by assigning progressively negative decision values. The presented method is based on unsupervised and non-model-based approaches, and hence there is no need for any representative numerical/finite element model of the structure to be created. To demonstrate the feasibility of the method in the detection and assessment of gradually evolving deterioration, it is tested on a replicate structure of a concrete jack arch which is a main structural component on the Sydney Harbor Bridge – one of Australia’s iconic structures. The test structure is a concrete cantilever beam with an arch section which is located on the eastern side of the bridge underneath the bus lane. A cut is introduced to the structure using a saw and its length is progressively increased in four stages while the depth is kept constant; these four damage cases correspond to less than 0.5% reduction in the first three vibrational modes of the structure which is considered a very small damage. It is demonstrated that the presented method can reliably detect the progression of the crack in the structure and thus can enable the real-time monitoring of infrastructures

ANPEd e Intercom: panorama da produção dos pesquisadores em Educação e Comunicação na última década

O artigo expõe resultados parciais de pesquisa que investiga características das propostas voltadas ao tema educação formal e comunicação, a partir dos artigos publicados entre os anos de 2000 e 2010, nos anais dos grupos de pesquisa sobre Educação e Comunicação ligados à ANPEd e à Intercom. O estudo identificou convergência quanto aos pressupostos teóricos, concepções sobre a instituição escolar e propostas para a educação formal, fatores que ajudam a consolidar um campo de saber específico