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Francesco Bellotti Riccardo Berta Alessandro De Gloria Massimiliano Margarone 《Personal and Ubiquitous Computing》2002,6(3):155-163
Future generation cars will be characterized by a wide range of Information Technology (IT) services providing safety and
infotainment. This makes the car an information intensive environment where the visual channel is overloaded, putting the
safety of drivers and passengers in jeopardy. We propose the use of a 3D auditory display to provide information from the
Advanced Driver Assistance Systems. This reduces the eye-off-road time, exploiting the human capability to associate sounds
with positions in space. Preliminary lab tests reveal the suitability of this approach. The system still has to be carefully
tuned and personalized to achieve usability and reliability, but we think that it provides a complementary channel that is
specially useful in low visibility conditions. 相似文献
23.
Paulo S. André António L. Teixeira Armando N. Pinto Lara P. Pellegrino Berta B. Neto José F. Rocha Joäo L. Pinto Paulo N. Monteiro 《ETRI Journal》2006,28(2):257-259
In this letter, we will evaluate the performance degradation of a 40 km high‐speed (40 Gb/s) optical system, induced by optical fiber variations of the chromatic dispersion induced by temperature changes. The chromatic dispersion temperature sensitivity will be estimated based on the signal quality parameters. 相似文献
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25.
In this paper, we describe the development of the variable dimension and variable sample size T2 control chart (VSSVDT2), which is an enhancement of the variable dimension T2 chart (VDT2). In the VDT2 control chart, the number of variables that are measured to compute the T2 statistic is made variable. Some of the variables are easy or inexpensive to measure and are always monitored. The variables that are more difficult or expensive to measure are measured only when the T2 value from the previous sample exceeds a specified threshold. The VDT2 control chart performs well for moderate and large shifts in the mean vector. However, its performance for small shifts is poor. To improve the chart’s performance in detecting such shifts, we propose the application of the variable sample size technique to the VDT2 control chart, resulting in the VSSVDT2 control chart. To promote the use of the VSSVDT2 chart, a user-friendly software has been developed, which the final user can use to find the best parameters of the VSSVDT2 chart for a particular process. 相似文献
26.
F. H. S. Sales Ana L. Dantas V. D. Mello A. S. Carri?o 《Journal of Materials Science》2010,45(18):5036-5039
We report a theoretical investigation of new magnetic phases of thin dysprosium films. At the surfaces, the balance between exchange and anisotropy energies favors the alignment of spins along the basal plane easy axis directions. Near the Curie temperature, the helimagnetic phase is strongly modified, allowing surface spins to lock into the basal plane anisotropy easy directions. As the temperature raises, we find transitions to other surface lockin patterns, which are tunable by external field strengths of a few hundred milli-Oersteds. 相似文献
27.
Hugo M. Santos Bruno Pedras Abel Tamayo Jaume Casabó Lluis Escriche Berta Covelo José Luis Capelo Carlos Lodeiro 《Inorganic chemistry communications》2009,12(11):1128-1134
Two new emissive chemosensors based on coumarin-343 have been synthesized, and their photophysical studies conducted. L1 contains an aza-thio macrocycle ring as the chelating unit, which has great affinity for soft metal ions, whereas L2 is a parent species without macrocyclic unit. Both compounds were separated by column chromatography and characterized by elemental analysis, 1H,13C NMR, UV–vis and FAB mass spectroscopy. The X-ray structures of L1 and L2 and the supramolecular interactions in the solid state are discussed. Preliminary results on the metal–ion sensing effects of the ligands are presented. Titrations with Ag+, Pd2+ and Ni2+ have been studied by UV–vis absorption and fluorescence spectroscopy. 相似文献
28.
Berta Gonçalves Ana Paula Silva José Moutinho-Pereira Eunice Bacelar Eduardo Rosa Anne S. Meyer 《Food chemistry》2007,103(3):976-984
The relationship between colour parameters and anthocyanins of four sweet cherry cultivars, Burlat, Saco, Summit and Van was studied. The colour (L∗, a∗, b∗, chroma and hue angle parameters) and anthocyanins were analysed during two different years at two different ripening stages (partially ripe, and ripe, respectively). The cherries were analysed at harvest and after storage at 1.5 ± 0.5 °C and 15 ± 5 °C for 30 and 6 days, respectively. The colour was measured by tristimulus colourimetry (CIELAB system) directly on the fruits, while anthocyanins were quantified by HPLC-DAD analysis on methanolic extracts of freeze-dried samples of the fresh cherries and on the differently stored cherries. L∗, chroma, and hue angle values were always lower for the ripe than for the partially ripe cherries. All of the cultivars were found to contain cyanidin-3-rutinoside and cyanidin-3-glucoside as the major anthocyanins. The total anthocyanin content in fruits of the different cultivars varied in the order Burlat > Saco > Van > Summit. The concentration of anthocyanins increased at both temperatures of storage in both ripe and partially ripe cherries, but the extent of increase varied among cultivars. Cherries stored at 15 ± 5 °C showed higher reduction of L∗, chroma and hue angle than fruits stored at 1.5 ± 0.5 °C. L∗, a∗, b∗, chroma and hue angle correlated negatively (P < 0.001) with the total anthocyanins levels, but not with the total phenols. These results show that chromatic functions of chroma and hue correlate closely with the evolution of colour and anthocyanins levels during storage of sweet cherries and indicate that colour measurements can be used to monitor pigment evolution and anthocyanin contents of cherries (and vice versa). 相似文献
29.
Fernandez J. Hidalgo S. Paredes J. Berta F. Rebollo J. Millan J. Serra-Mestres F. 《Electron Device Letters, IEEE》1989,10(5):212-215
An analytical ON-resistance expression for different designs of VDMOS (vertically diffused metal-oxide-semiconductor) devices which takes into consideration the two-dimensional (2-D) nature of the current flow is obtained. This expression differs from other models that overestimate this resistance for large cell spacings. This formulation is in close agreement with experimental points obtained from the interdigitated fabricated structures and with 2-D simulations. Moreover, the effect of a two-level oxide thickness on the ON resistance has been investigated for the interdigitated case 相似文献
30.
Andreea Bucurescu Alexandra Cristina Blaga Berta N. Estevinho Fernando Rocha 《Food and Bioprocess Technology》2018,11(10):1795-1806
Curcumin is a natural yellow pigment extracted from dried roots of turmeric, used in food applications. Despite its applicability in food products, this phenolic compound is also used in the pharmaceutical field. It is reported to have health benefits such as anticancer, antitumor, and antiviral effects. However, curcumin is a very unstable compound. Therefore, this work proposes the microencapsulation of curcumin, in order to protect it and to improve its stability and solubility in water, by spray-drying, using the gum arabic as an encapsulating agent in three different concentrations 10, 15, and 20% (weight/volume (w/v)). Emulsions were prepared with coconut oil and used to prepare the curcumin microparticles. For this purpose, different analysis and studies were performed. A product yield ranging from 44 to 52% and from 29 to 42% was obtained for the production of microparticles without and with curcumin, respectively. The curcumin microcapsules and empty capsules were characterized and evaluated. All the microparticles presented a spherical form, had a diameter around 7–9 μm (considering a volume distribution), and had a rough surface. The efficiency of encapsulation was between 75 and 85%, being higher for the particles prepared with higher concentrations of encapsulating agents. Considering the controlled release studies, the microcapsules were prepared with different concentrations of gum arabic but showed similar release profiles. However, it was also concluded that increasing the amount of gum arabic used in the formulation of the microparticles, the amount of curcumin released in the first minutes decreases; therefore, the release tends to be slower (63.2% of the release varied between 25.5 and 69.0 min). Fitting the experimental results to a linearized equation of the Weibull model, it was possible to obtain a good correlation coefficient (R2 varying from 0.94 to 0.97), indicating that this model adapts to the experimental data obtained. 相似文献