Bandwidth and memory efficiency in real-time ray tracing

Real time ray tracing has been given a lot of attention in recent years in the academic and research community. Several novel algorithms have appeared that parallelize different aspects of the ray tracing algorithm through the use of a GPU. Among these, the creation of Bounding Volume Hierarchies (BVHs). We believe that recent approaches have failed to consider the performance impact of memory accesses in GPU and how their cost affects the overall performance of the application. In this work we show that by reducing memory bandwidth and footprint we are able to achieve significant improvements in BVH traversal times. We do this by compressing the BVH and the triangle mesh in a parallel manner after its creation, in each frame, and then decompressing it as needed while traversing the BVH

Kiln dry probes verification for maritime pine and eucalyptus wood

Comunicação apresentada na 8th International IUFRO Wood Drying Conference, que decorreu de 28 a 29 de Agosto em Brasov na Roménia.Proper technical drying is a condition for processing sawn timber into high quality products. The drying process is a phase with an extreme importance in wood transformation process, because it gives a significant improvement to the characteristics of workability, prevents damage during transport and insects or fungi attack (Tsoumis, 1991; Walker, 1993). One of the most critical and important phases in the kiln dry is the perfect knowledge of moisture evolution in wood that is drying and is given by the probes measures. Therefore, it became necessary estimate frequently the wood moisture content, which should be at the same time accurate and practical. The objective of the present study is to verify the fiability of the data given by different probes types, and between the values given by this and the ones obtains by laboratory. This work was done in 2 different industrial dryers and in a laboratory dryer. There were executed several simple regression analysis to evaluated the existent relation between this ones and the ones obtain in laboratory; it was observed that to values until 30% of moisture it exist a strong correlation between this two parameters but the same it wasn’t observed to higher moisture contents. It was made the confrontation between the result obtain in Maritime pine (Pinus pinaster) and Eucalyptus (Eucaliptus globulus), and it was observed that the probes can evaluated the moisture content with higher accuracy in pine comparing with eucalyptus. So, it is necessary have some caution when the probes are disconnected, during the kiln dry process, specially to moisture content values are higher then 30%, because the values given by them are some times liable to error

Análise da qualidade das águas superficiais de Ponte de Lima

No âmbito do tema recursos hídricos e o conceito de sustentabilidade, foi desenvolvido um estudo de caracterização do estado das águas superficiais, de uma área geográfica específica do Alto Minho. O desenvolvimento do estudo assentou numa base temporal e espacial de análise de parâmetros organolépticos, físico-químicos e microbiológicos. Fez-se uma previsão espacial e temporal de parâmetros de qualidade ao longo do rio, de montante para jusante, exclusivamente até aos pontos de amostragem (estações) referentes à área em estudo. Caracterizou-se alguns aspectos hidrográficos da bacia hidrográfica onde está inserida a região em estudo e também deu-se alguma relevância a aspectos sanitários da Estação de Tratamento de Águas Residuais da região. Foram também definidas algumas tendências em termos de indicadores fulcrais de sustentabilidade

A new methodology for the characterization of mode II fracture of pinus pinaster wood

In this study, the End Notched Flexure (ENF) fracture test was used to obtain the mode II Rcurve of the Pinus pinaster wood in the RL crack propagation system. The test method was numerically and experimentally analyzed. In the numerical study, three (3D) and twodimensional (2D) finite element analyses were conducted to determine the mode II critical strain energy release rate (GIIc) and the respective R-curve. Firstly, the 3D analysis was performed in order to obtain the strain energy release rates distributions at the crack tip, and consequently, to identify the presence of spurious fracture modes that could affect the measured GIIc. The P-δ-a values determined from the 3D model were compared with the same values obtained from the 2D model. The main objective was to validate the 2D model, which is computationally less expensive. On the other hand, measurement of the crack length in the ENF test is quite difficult in wood because crack tends to close during propagation. To avoid this experimental problem a Compliance-Based Beam Method (CBBM), based on equivalent crack approach, is proposed. Moreover, this method does not require additional experimental tests to obtain the elastic properties. Experimental tests were also executed in order to verify the numerical results. The aim is to introduce the CBBM as a standard data reduction scheme in order to measure the GIIc value

Sibilant consonants classification with deep neural networks

Abstract. Many children su ering from speech sound disorders cannot pronounce the sibilant consonants correctly. We have developed a serious game that is controlled by the children's voices in real time and that allows children to practice the European Portuguese sibilant consonants. For this, the game uses a sibilant consonant classi er. Since the game does not require any type of adult supervision, children can practice the production of these sounds more often, which may lead to faster improvements of their speech. Recently, the use of deep neural networks has given considerable improvements in classi cation for a variety of use cases, from image classication to speech and language processing. Here we propose to use deep convolutional neural networks to classify sibilant phonemes of European Portuguese in our serious game for speech and language therapy. We compared the performance of several diferent arti cial neural networks that used Mel frequency cepstral coefcients or log Mel lterbanks. Our best deep learning model achieves classi cation scores of 95:48% using a 2D convolutional model with log Mel lterbanks as input features.info:eu-repo/semantics/publishedVersio

Explicit instructions do not enhance auditory statistical learning in children with developmental language disorder: evidence from event-related potentials

A current issue in psycholinguistic research is whether the language difficulties exhibited by children with developmental language disorder [DLD, previously labeled specific language impairment (SLI)] are due to deficits in their abilities to pick up patterns in the sensory environment, an ability known as statistical learning (SL), and the extent to which explicit learning mechanisms can be used to compensate for those deficits. Studies designed to test the compensatory role of explicit learning mechanisms in children with DLD are, however, scarce, and the few conducted so far have led to inconsistent results. This work aimed to provide new insights into the role that explicit learning mechanisms might play on implicit learning deficits in children with DLD by resorting to a new approach. This approach involved not only the collection of event-related potentials (ERPs), while preschool children with DLD [relative to typical language developmental (TLD) controls] were exposed to a continuous auditory stream made of the repetition of three-syllable nonsense words but, importantly, the collection of ERPs when the same children performed analogous versions of the same auditory SL task first under incidental (implicit) and afterward under intentional (explicit) conditions. In each of these tasks, the level of predictability of the three-syllable nonsense words embedded in the speech streams was also manipulated (high vs. low) to mimic natural languages closely. At the end of both tasks’ exposure phase, children performed a two-alternative forced-choice (2-AFC) task from which behavioral evidence of SL was obtained. Results from the 2-AFC tasks failed to show reliable signs of SL in both groups of children. The ERPs data showed, however, significant modulations in the N100 and N400 components, taken as neural signatures of word segmentation in the brain, even though a detailed analysis of the neural responses revealed that only children from the TLD group seem to have taken advantage of the previous knowledge to enhance SL functioning. These results suggest that children with DLD showed deficits both in implicit and explicit learning mechanisms, casting doubts on the efficiency of the interventions relying on explicit instructions to help children with DLD to overcome their language difficulties.info:eu-repo/semantics/publishedVersio

Rationale, application and clinical qualification for NT-proBNP as a surrogate end point in pivotal clinical trials in patients with AL amyloidosis

Amyloid light-chain (LC) amyloidosis (AL amyloidosis) is a rare and fatal disease for which there are no approved therapies. In patients with AL amyloidosis, LC aggregates progressively accumulate in organs, resulting in organ failure that is particularly lethal when the heart is involved. A significant obstacle in the development of treatments for patients with AL amyloidosis, as well as for those with any disease that is rare, severe and heterogeneous, has been satisfying traditional clinical trial end points (for example, overall survival or progression-free survival). It is for this reason that many organizations, including the United States Food and Drug Administration through its Safety and Innovation Act Accelerated Approval pathway, have recognized the need for biomarkers as surrogate end points. The international AL amyloidosis expert community is in agreement that the N-terminal fragment of the pro-brain natriuretic peptide (NT-proBNP) is analytically validated and clinically qualified as a biomarker for use as a surrogate end point for survival in patients with AL amyloidosis. Underlying this consensus is the demonstration that NT-proBNP is an indicator of cardiac response in all interventional studies in which it has been assessed, despite differences in patient population, treatment type and treatment schedule. Furthermore, NT-proBNP expression is directly modulated by amyloidogenic LC-elicited signal transduction pathways in cardiomyocytes. The use of NT-proBNP will greatly facilitate the development of targeted therapies for AL amyloidosis. Here, we review the data supporting the use of NT-proBNP, a biomarker that is analytically validated, clinically qualified, directly modulated by LC and universally accepted by AL amyloidosis specialists, as a surrogate end point for survival.Leukemia advance online publication, 2 August 2016; doi:10.1038/leu.2016.191

An input on the characterization of timber frame structural system of tabique walls

Tabique construction corresponds to a relevant Portuguese heritage. Urban and rural tabique construction exists all over the country. This traditional building technique started to be in disuse after the massive introduction of the reinforced concrete. Therefore, tabique buildings are already aged and, in general, they show signals of degradation. Recent research works have concluded that this degradation stage is essentially caused by the absence of a regular proper maintenance process. The fact that tabique buildings are mainly private property, that there are economical limitations and that there is still a lack of knowledge concerning this traditional building technique, have been the main reasons identified. In order to contribute solving this problem this paper intends to give an input on the characterization of timber frame structural system of tabique walls. In fact, a tabique building element is a structural system formed by a timber frame coated with an earthy render. The elements of the timber frame are nailed to each other. It has been noticed that there are different types of timber frames. Given technical information related to these alternative traditional structural solutions may be helpful in future rehabilitation processes. At the same time, the relevance of this information is even more expressive taking into account the following aspects: a) the access of this type of buildings is in general limited because they are private properties; b) they have been abandoned and, therefore, they are not accessible; c) they became a ruin and they are not safe to be accessed; d) they were demolished