Towards enhanced visual clarity of sign language avatars through recreation of fine facial detail

Machine Translation - Facial nonmanual signals and expressions convey critical linguistic and affective information in signed languages. However, the complexity of human facial anatomy has made the...     

Revisiting the strength of micron-scale ceramic platelets

Individual platelets in nacre-like ceramics are able to locally withstand stress levels many times larger than the strength of larger specimens made of the same materials. This size effect, usually reported as being relative to the size of pre-existing defects, is described by considering both stress and energy failure conditions. We show that there is a characteristic length, defined by the material's Young's modulus, fracture energy, and strength, above which failure is governed by a stress criterion and below which energy considerations are dominant. Applying the coupled criterion to three-point bending of a single alumina platelet allows the identification of the platelet strength and fracture energy. The proposed approach also allows capturing the decrease in failure stress due to a surface defect accounting for its shape and size.     

Thin Film Growth on Quasicrystalline Surfaces

The surfaces of quasicrystals have proved to be a very interesting playground for thin film growth. They offer a complex potential energy surface where heterogeneous nucleation of islands at specific quasilattice sites is frequently observed. These islands tend to locally adopt the symmetry of the quasicrystalline substrate. For some specific adsorbates, a complete 2-dimensional quasiperiodic metal overlayer is even formed. Other interesting phenomena are also observed in the multilayer regime. This includes the formation of novel structures, like 1-dimensional quasiperiodic Cu films or Bi allotropes, the formation of nanoscale crystalline domains with 5-fold rotational epitaxy, or the occurrence of quantum size effects influencing the film morphology. This article presents a short review of some of the achievements in thin film growth on quasicrystalline surfaces that the discovery of quasicrystals by Dan Shechtman has enabled.     

Active cooling of a mobile phone handset

Power dissipation levels in mobile phones continue to increase due to gaming, higher power applications, and increased functionality associated with the internet. The current cooling methodologies of natural convection and radiation limit the power dissipation within a mobile phone to between 1-2 W depending on size. As power dissipation levels increase, products such as mobile phones will require active cooling to ensure that the devices operate within an acceptable temperature envelop from both user comfort and reliability perspectives. In this paper, we focus on the applied thermal engineering problem of an active cooling solution within a typical mobile phone architecture by implementing a custom centrifugal fan within the mobile phone. Its performance is compared in terms of flow rates and pressure drops, allowable phone heat dissipation and maximum phone surface temperature as this is the user constraint for a variety of simulated PCB architectures in the mobile phone. Perforated plates with varying porosity through different size orifices are used to simulate these architectures. The results show that the power level dissipated by a phone for a constant surface temperature may be increased by ～50 - 75% depending on pressure drop induced by the internal phone architecture. Hence for successful implementation and efficient utilization of active cooling will require chip layout to be considered at the design stage.     

Progress in the Development of Platelet‐Activating Factor Receptor (PAFr) Antagonists and Applications in the Treatment of Inflammatory Diseases

Platelet‐activating factor (PAF) and its receptor (PAFr) have been implicated in a wide range of diseases and disorders that originate from the activation of inflammatory pathways. Although the exact structure of the binding site on the PAFr remains unknown, the PAFr is a well‐established therapeutic target, and an array of structurally diverse PAFr antagonists have been identified. These include compounds that are structurally similar to the natural PAF ligand, synthetic heterocycles, complex polycyclic natural products, and various metal complexes. This review provides an update on more than 20 years of progress in this area. The development and synthesis of new PAFr antagonists, structure–activity relationship studies, the biological activity of these molecules, and their therapeutic potential are discussed.     

Characterization of NaPO3–SnO–WO3 glasses prepared by microwave heating

Phosphate glasses containing tin and tungsten oxides were produced by microwave heating under a nitrogen protective atmosphere. Microwaves permit to heat the raw materials at temperatures close to 1000 °C in short time and to obtain homogeneous glasses in less than 10 min. All samples were characterized from thermal and mechanical point of view as function of metal oxide proportions. The equimolar addition of SnO and WO₃ in sodium phosphate matrix involves a linear evolution of the different properties (T _g, CTE, density, mechanical properties, and durability). Thus, we have shown a progressive strengthening of the network. The glass transition temperature does not exceed 405 °C, and the chemical durability is improved to four orders of magnitude. The dissolution rate is equal to 3.4 × 10⁻⁷ g cm⁻² min⁻¹ for 40NaPO₃–30SnO–30WO₃ glass composition and is comparable with those of the window glass.     

Finding an application-appropriate model for XML data warehouses

Decision support systems help the decision making process with the use of OLAP (On-Line Analytical Processing) and data warehouses. These systems allow the analysis of corporate data. As OLAP and data warehousing evolve, more and more complex data is being used. XML (Extensible Markup Language) is a flexible text format allowing the interchange and the representation of complex data. Finding an appropriate model for an XML data warehouse tends to become complicated as more and more solutions appear. Hence, in this survey paper we present an overview of the different proposals that use XML within data warehousing technology. These proposals range from using XML data sources for regular warehouses to those using full XML warehousing solutions. Some researches merely focus on document storage facilities while others present adaptations of XML technology for OLAP. Even though there are a growing number of researches on the subject, many issues still remain unsolved.     

Robust distributed speech recognition in noise and packet loss conditions

This paper examines the performance of a Distributed Speech Recognition (DSR) system in the presence of both background noise and packet loss. Recognition performance is examined for feature vectors extracted from speech using a physiologically-based auditory model, as an alternative to the more commonly-used Mel Frequency Cepstral Coefficient (MFCC) front-end. The feature vectors produced by the auditory model are vector quantised and combined in pairs for transmission over a statistically modelled channel that is subject to packet burst loss. In order to improve recognition performance in the presence of noise, the speech is enhanced prior to feature extraction using Wiener filtering. Packet loss mitigation to compensate for missing features is also used to further improve performance. Speech recognition results show the benefit of combining speech enhancement and packet loss mitigation to compensate for channel and environmental degradations.