Adaptive Resource Sharing Strategies for UMTS Multiservice Mobiles

In this paper, a multiservice transmission scheme which joints voice, video, interactive game and signaling is evaluated for the dedicated channel of the Universal Mobile Telecommunications System. The transmission rate for each service is determined by means of an adaptive transport format selection. In the UMTS standard, this selection is based on power allocation provided by radio resource controller, trying to match the Eb/No requirements of the individual services. An appropriate selection of the individual rates of each multiplexed service, taking into account its particular QoS requirements, will provide a more efficient resource management than the transmission only restricted to power allocation. For this purpose, we propose and evaluate a new selection strategy based on buffer occupation, delay requirements and target bit rate keeping power constraints that intends to improve the basic operation trying to minimize the impact of the whole network. Video and game services are multiplexed in upper layers (logical channels) sharing a common transmission rate (transport channel). In this paper, it is proposed a new strategy to share the transmission rate set for this transport channel between both services taking into account their particular requirements. Results show that considering delay constraints provides a more balanced performance of the multiplexed services.     

Texture evolution of “Amaretti” cookies during storage

The results of a study on texture evolution during 35 days of storage of amaretti, a typical Italian cookie, packaged in two different ways are reported. Amaretti cookies were wrapped in polyvinylchloride (PVC) film or aluminium foil (ALL), to simulate two different permeability conditions and stored at controlled temperature and humidity. Evolution of texture (such as hardness) and a_w were tested instrumentally by a texture analyser and a hygrometer, respectively. Texture was assessed by a cut and puncturing test. Indices for hardening were the area under the curve (N mm) and gradient (N/mm) for the puncturing test and maximum force (N) for the cut test. Both textural tests showed significantly higher hardening of PVC cookies, compared to the ALL cookies. The latter retained good sensorial properties at the end of the storage period, although their internal structure changed from soft and moist to mealy, while the PVC cookies were no longer edible only 10 days after baking. a_w values decreased and increased in PVC and ALL lots, respectively. The results suggest that hardening may be explained by water loss in PVC and moisture redistribution in ALL.     

Redundant system of passive markers for ultrasound scanhead tracking

Scanhead tracking by opto-electronic (OE) systems allows high accuracy in three-dimensional (3-D) freehand ultrasound imaging. In this paper, a new set of methods is proposed and compared with the standard approach [Gram-Schmidt method (GS)]. Three redundancy-based algorithms are introduced to compensate for possible loss of markers during data acquisition: regression plane (RP), multiple Gram-Schmidt (MGS), and center of mass least square (CMLS). When combined with the ultrasound instrument, the root-mean-squared (RMS) uncertainty in locating target points, over a working volume of 420 mm x 490 mm x 100 mm, improved by 7% and 24% using MGS and CMLS method respectively, compared to GS. A lower improvement was obtained with RP methods (5%), using the best marker configuration. In conclusion, CMLS method provides a robust and accurate procedure for 3-D freehand ultrasound scanhead tracking, able to manage possible loss of markers, with interesting perspectives for image fusion and body referenced 3-D ultrasound.     

Autogestion de Réseaux de Capteurs Sans Fil : Services, Fonctions, Modèles et Étude de Cas

The wireless sensor networks (Wsn) are a novel technology that has appeared after great advancements in the development of intelligent sensors, powerful microprocessors, and communication protocols, their basic components. This kind of network is composed by hundreds to thousands of elements and has the objective of data collecting, processing, and disseminating to a point of interest. The network elements, named sensors nodes, have small dimensions and resource restrictions, especially the energy, the processing, and the communication capacities. It is expected that theWsn are intelligent, autonomic, and context aware. To reach such an objective, they are supposed to perform the management of themselves, i.e., be self-managed. In this article, we propose a management solution for such a sort of network, based on the autonomic computing paradigm. In order to show that self-management can improve the productivity of the network and control the quality of the provided services, we present a case study of a heterogeneous and hierarchicWsn that collects and disseminates data continuously.     

Convergence of the IRWLS Procedure to the Support Vector Machine Solution

An iterative reweighted least squares (IRWLS) procedure recently proposed is shown to converge to the support vector machine solution. The convergence to a stationary point is ensured by modifying the original IRWLS procedure.     

Intelligent virtual agents keeping watch in the battlefield

One of the first areas where virtual reality found a practical application was military training. Two fairly obvious reasons have driven the military to explore and employ this kind of technique in their training; to reduce exposure to hazards and to increase stealth. Many aspects of combat operations are very hazardous, and they become even more dangerous if the combatant seeks to improve his performance. Some smart weapons are autonomous, while others are remotely controlled after they are launched. This allows the shooter and weapon controller to launch the weapon and immediately seek cover, thus decreasing his exposure to return fire. Before launching a weapon, the person who controls that weapon must acquire/perceive as much information as he can, not only from its environment, but also from the people who inhabits that environment. Intelligent virtual agents (IVAs) are used in a wide variety of simulation environments, especially in order to simulate realistic situations as, for example, high fidelity virtual environment (VE) for military training that allows thousands of agents to interact in battlefield scenarios. In this paper, we propose a perceptual model, which seeks to introduce more coherence between IVA perception and human being perception, increasing the psychological coherence between the real life and the VE experience. Agents lacking this perceptual model could react in a non-realistic way, hearing or seeing things that are too far away or hidden behind other objects. The perceptual model, we propose in this paper introduces human limitations inside the agents perceptual model with the aim of reflecting human perception.     

PCBs and selected organochlorine compounds in Italian mountain air: the influence of altitude and forest ecosystem type

Passive air samplers (polyurethane foam disks) were deployed on an altitudinal transect in the rural Italian Alps to investigate the potential influence of forest cover on air concentrations. Samplers were exposed overtwo periods, each of several weeks, either in clearings or in forests. In the first period, there was high leaf coverage (high leaf area index, LAI); in the second, the LAI was low after the autumnal leaf fall. PCBs sequestered in the PUF generally declined with altitude, for example, in the clearings PCBs-28, 52, 90/101, 118, and 138, all showed statistically significant declines (p < 0.05). The mass of HCB sequestered increased with altitude, evidence of cold condensation. Ratios of the forest:clearing concentrations were calculated; this ratio expresses the filtering ability of forests to deplete air concentrations compared to the adjacent clearings. During the high LAI sampling period, these depletion factors ranged between 0.93 and 0.54 and were inversely correlated with temperature-corrected log K0A. This relationship was notobserved during the low LAI sampling period. The depletion factors were normalized using the LAI to give a density independent depletion factor (DIDF). The slopes of the correlations with K0A were comparable for broadleaf or coniferous forests at different altitudes, suggesting that leaf surfaces determine the exchanges with air. Broadleaf forests at 1000 and 1400 m showed similar behavior, while a conifer forest at 1800 m gave depletion factors which were higher by about a factor of 2. It is suggested that DIDF can be used in regional environmental fate models to estimate the contribution of forests to contaminant fate.     

Comparison of methods for the assessment of growth of food spoilage moulds in solid substrates

The objective of the study was to evaluate the general suitability of ergosterol content, CFU, and colony diameters determinations for a range of fungi representing food spoilage moulds for the assessment of their growth on solid substrates, in particular intermediate moisture foods. Sixteen food-borne mould species were inoculated onto DG18 agar overlaid with cellophane, allowing determination of a direct measurement of biomass density weighing. The samples were also evaluated with regard to visible and microscopic colony diameters, total ergosterol content, Thoma counts, viable CFU counts, and so on. The same parameters were assayed in the spore suspensions obtained from those cultures. Data were evaluated by multivariate data analysis using projection methods such as principal component analysis (PCA), showing some groupings among the measured variables, mainly linked to the sporulating/nonsporulating nature of the different species tested. Ratios among the different variables were obtained, compared among the species, and evaluated along time (2-10 days). It was concluded that, as a general rule for all the species, ergosterol content and colony diameters were better correlated to fungal biomass dry weight than CFU counts were. Conversion factors were 0.3-3 microg ergosterol mg(-1) biomass dry weight and 76-227 mg biomass dry weight cm(-2), depending on the species.     

Correlation between morphology and stress—strain properties of three block copolymers i. stress-softening effect

The stress-softening effect, which comes out when SBS three block copolymers are stretched, is taken into consideration and the conclusion is reached that it is due to a disruption of the polystyrene continuous phase, according to the hypothesis of other authors. This conclusion is supported by two kinds of experiments performed on samples having a well known and simple morphology. First of all by stress-strain measurements on specimens previously swollen: it can be seen that the stress-softening effect disappears as soon as the structure of the material is completely modified by the treatment. Secondly by the direct observation at the electron microscope of the structure after the deformation. This shows how the original continuous and regular polystyrene rods of the “single crystal” assume a string of pearl structure which finally is irreversibly disrupted.