Amostragem multi-adaptativa de tráfego de rede

http://crc2011.uc.pt/A monitorização eficiente de redes e serviços tem um papel crucial no suporte à gestão e engenharia das redes de comunicações atuais. Obter uma visão realista do estado da rede sem, no entanto, interferir na sua operação normal é essencial no suporte à decisão dos operadores de redes e dos sistemas auto-configuráveis. Neste sentido, as técnicas de amostragem de tráfego procuram reduzir o impacto da monitorização no funcionamento da rede, mantendo a acurácia na estimação de parâmetros referentes ao seu comportamento estatístico. Embora seja observada uma evolução das atuais técnicas na correta estimação do desempenho da rede, o overhead associado ao volume de dados envolvidos nos processos de amostragem de tráfego ainda é considerável. Neste contexto, este trabalho propõe uma nova técnica de amostragem multi-adaptativa de tráfego, baseada em predição linear, que tem por objetivo reduzir significativamente o volume total de dados envolvidos na monitorização do estado da rede, sem comprometer a representatividade das amostras na estimação dos parâmetros em análise. A avaliação desta proposta, com base em coletas de tráfego real, demonstra que é possível reduzir significativamente o volume de dados analisado e mesmo assim alcançar, em vários parâmetros de caracterização, resultados mais precisos que as técnicas classicamente utilizadas

Para o estudo da evolução do ensino e da formação em administração educacional em Portugal

Estudos sobre a evolução do ensino de disciplinas, na formação de professores em Portugal, são recentes. O controle burocrático centralizado reteve as dimensões do controle político-administrativo. De certo modo, protegeu a esfera educativa das influências modernizantes, do capitalismo industrial e das lógicas mercantis e gerencialistas. Defendeu a educação do domínio político, da intervenção de movimentos sociais, das propagandas de ideais democráticos e da cidadania. A utilização da designação "Administração educacional" ilustra as dificuldades sentidas, ao longo dos últimos anos, em termos da construção acadêmica de uma área, seja pela falta de tradição, seja pelos antecedentes históricos.In Portugal, studies about the evolution of disciplines teaching in the teachers formation are recent. The centralized bureaucratic control has held back the dimensions of politic administrative control. In a certain way, it has protected the education against the new-fashioned influences, manufacturing capitalism, and mercantile and managerial logics. This centralized bureaucratic control has also profected the education against the politic dominion, the intervention of social movements, the advertising of democratic ideals, and against the citizenship. The use of the term "Educational administration" shows the difficulties met by the searchers along the latest years, since there is no tradiction nor historic antecedence

Enhancing traffic sampling scope and efficiency

Traffic Sampling is a crucial step towards scalable network measurements, enclosing manifold challenges. The wide variety of foreseeable sampling scenarios demands for a modular view of sampling components and features, grounded on a consistent architecture. Articulating the measurement scope, the required information model and the adequate sampling strategy is a major design issue for achieving an encompassing and efficient sampling solution. This is the main focus of the present work, where a layered architecture, a taxonomy of existing sampling techniques distinguishing their inner characteristics and a flexible framework able to combine these characteristics are introduced. In addition, a new multiadaptive technique proposal, based on linear prediction, allows to reduce the measurement overhead significantly, while assuring that traffic samples reflect the statistical behavior of the global traffic under analysis.Fundação para a Ciência e a Tecnologia (FCT

Assessing positional accuracy of drainage networks extracted from ASTER, SRTM and OpenStreetMap

This study intends to evaluate the positional accuracy and compare the completeness of the drainage networks extracted from three sources of free geographic data, namely from the Digital Elevation Models ASTER and SRTM and the collaborative project OpenStreetMap (OSM), in an area included in the basin of Mondego river, located in the centre of continental Portugal. The drainage networks extracted from ASTER and SRTM are generated considering several values of flow accumulation as the critical level to identify the water courses and the feature “waterway” was extracted from OSM. To assess the completeness and positional accuracy of these water courses the drainage network of the 1/25000 topographic map of the Portuguese Army Geographical Institute was used as reference. The distance between the ASTER, SRTM and OSM derived water courses to the reference data was computed as well as the length of the water courses and the results compared

A robust feature extraction for automatic speech recognition in noisy environments

This paper presents a method for extraction of speech robust features when the external noise is additive and has white noise characteristics. The process consists of a short time power normalisation which goal is to preserve as much as possible, the speech features against noise. The proposed normalisation will be optimal if the corrupted process has, as the noise process white noise characteristics. With optimal normalisation we can mean that the corrupting noise does not change at all the means of the observed vectors of the corrupted process. As most of the speech energy is contained in a relatively small frequency band being most of the band composed by noise or noise-like power, this normalisation process can still capture most of the noise distortions. For Signal to Noise Ratio greater than 5 dB the results show that for stationary white noise, the normalisation process where the noise characteristics are ignored at the test phase, outperforms the conventional Markov models composition where the noise is known. If the noise is known, a reasonable approximation of the inverted system can be easily obtained performing noise compensation still increasing the recogniser performance

MIARforest Reproducibility and Reliability for Assessing Occupational Risks in the Rainforest

The Method for the Integrated Assessment of Risks for rainforest (MIARforest) is a specific methodology for assessing the risk of occupational accidents associated with working in native tropical forests. MIARforest was validated for the results’ reproducibility and the reliability of calculated risk levels through the Delphi approach. Two rounds of questionnaires illustrating ten scenarios of activities associated with the logging process in the Eastern Amazon’s native rainforest (Brazil) were presented to forestry and occupational health and safety (OHS) experts. In the first round, the questionnaire was answered anonymously by 55 experts, and in the second, by 46. A percentage of agreement of at least 80% in each question was considered to close the process. Questions that did not meet the criterion in the first round were reassessed in the second round. The obtained results lead to the conclusion that MIARforest, an occupational accident risk assessment tool, has been effectively validated, demonstrating inter-rater reproducibility and reliability in determining risk values. These results highlight the objectivity and reliability of MIARforest.info:eu-repo/semantics/publishedVersio

Occupational Risk Assessment in Native Rainforest Management (MIARforest)—Parameters Definition and Validation

Maintaining native rainforests as a sustainable ecosystem and their resilience to external pressures involves their economic profitability as a natural resource of unique and renewable products. For this purpose, new approaches have been developed and refined. This work seeks to contribute in this direction in the context of occupational safety and health (OSH) by presenting a new method for integrated assessment of risks for rainforests (MIARforest). The MIARforest is based on the MIAR, a method that has shown promising results in occupational risk assessment in different industrial sectors. Its parameters were discussed and assessed to improve their relevance, wording and risk assessment through the Delphi methodology by a panel of 62 experts in forestry and OSH who responded independently to questionnaires made available through Google Forms. A consensus of over 79% among the experts was reached in two rounds. This result highlights the high objectivity and the low percentage of dubious possible interpretations of the parameters and sub-parameters of this occupational risk assessment method.info:eu-repo/semantics/publishedVersio

MALDI-TOF ICMS: capability, potentiality and limits in the fast identification of Trichophyton rubrum from clinical cases occurrence in Portuguese health centres

Objective: Trichophyton rubrum is presently the most common worldwide pathogen causing dermatophytoses such as tinea corporis, tinea capitis, tinea pedis, and onychomycosis [1]. The main aim of the present work was assess MALDI-TOF ICMS as a fast and reliable technique in the identification of T. rubrum from clinical cases occurrence in the Portuguese health centres, and evaluates the potentialities and limits of this new microbial identification technique on the taxonomy of these infectious dermatophytes. Methods: Fungi were grown for 10 days in solid medium (SDA, Sabouraud Dextrose Agar) and then the mycelia were direct transferred from the SDA plate to the MALDI stainless steel template and mixed with 1 ml MALDI matrix solution (75 mg/ml 2,5-dihydroxybenzoic acid in ethanol/water/acetonitrile [1:1:1] with 0.03% trifluoroacetic acid). The sample mixtures were air dried at room temperature. The analyses were performed in our laboratory on an Axima LNR system (Kratos Analytical, Shimadzu, Manchester, UK) equipped with a nitrogen laser (337 nm). The mass range from m/z = 2,000 to 20,000 Da was recorded. Escherichia coli strain DH5a with known mass values of ribosomal proteins was used for external calibration. The fungi classification was performed on the SARAMIS software (AnagnosTec mbH, Potsdam- Golm, Germany). Molecular biology was used when appropriated with PCR based-technology. The presence of a 203-bp PCR product confirmed T. rubrum identification. Results: All strains were accurately and consistently identified as T. rubrum by MALDI-TOF ICMS combined to SARAMIS database analysis. Spectral mass analysis proven to be a rapid method since the analysis took only a few minutes to perform with the benefit of any laborious sample preparation procedures or any expensive chemical reagent was needed. Conclusions: The fungal spectral analysis by MALDI-TOF ICMS was as good as molecular biology in order to identify T. rubrum but much faster and cheaper

Identification of clinical isolates Trichophyton rubrum using a rapid and accurate mass spectral analysis (MALDI‐TOF ICMS)

condition called “ringworm” in man. The affinity for keratinized tissues by dermatophytes, implies in most of the cases, that the infection remains restricted to the nonliving cornified layers of the skin, nails, and hair [1]. Among dermatophytes, the species Trichophyton rubrum is of particular clinical interest for man because is the most common agent of human dermatophytoses. Macro and micro‐morphological examination combined to physiological analysis of primary isolates grown in selective culture media are still the most used methods in routine laboratory. Besides their low specificity, an accurate diagnosis may take 3 to 4 weeks to be achieved Modern identification methods involve molecular biology by using PCR technology based on differential sequence elements. It is gradually becoming clearer that microbial identification and authentication requires a polyphasic approach to generate quality data which are accurate and useful [2]. Microbial mass spectral analysis has been progressively more incorporated to the polyphasic approach to improve the accuracy of the microbial identification issue. Matrix Assisted Laser Desorption Ionization Time of Flight Intact Cell Mass Spectroscopy (MALDI‐TOF ICMS) is becoming an alternative to DNA‐dependent methods so it has been already successfully applied to the rapid identification and classification of microorganisms [3].The aim of this work was to test the applicability of MALDI‐TOF ICMS for identifying clinical isolates of T. rubrum. In this study twenty clinical isolates of T. rubrum were grown on Sabouraud culture medium. Plates were incubated for 7 days at 25 ºC. All the isolates were identified both macroscopically and microscopically. From the same plate, a tiny sample (about 50 mg) was transferred to stainless steel templates. A 0.5 ml of dihydroxy‐benzoic acid (DHB) matrix solution was added to the sample and air dried. Peak lists of individual samples were compared with the superspectra database generating a ranked list of matching spectra from SARAMIS software. All strains were accurately and consistently identified as T. rubrum by MALDI‐TOF ICMS combined to SARAMIS database analysis. Spectral mass analysis proven to be a rapid method, as the analysis took only a few minutes to perform with the benefit of any laborious sample preparation procedures or any expensive chemical reagent was needed