215 research outputs found

    A robust motion estimation and segmentation approach to represent moving images with layers

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    The paper provides a robust representation of moving images based on layers. To that goal, we have designed efficient motion estimation and segmentation techniques by affine model fitting suitable for the construction of layers. Layered representations, originally introduced by Wang and Adelson (see IEEE Transactions on Image Processing, vol.3, no.5, p.625-38, 1994) are important in several applications. In particular they are very appropriate for object tracking, object manipulation and content-based scalability which are among the main functionalities of the future MPEG-4 standard. In addition a variety of examples are provided that give a deep insight into the performance bounds of the representation of moving images using layers.Peer ReviewedPostprint (published version

    Análisis del impacto del vehículo eléctrico en las redes españolas en 2050

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    La evolución y desarrollo tanto del vehículo eléctrico como de la generación distribuida es algo innegable, la duda que se presenta no es tanto si estas tecnologías van a crecer, sino a qué velocidad lo harán en los próximos años. En este proyecto se realiza una estimación de dicha evolución teniendo en cuenta diversos factores: la evolución y el precio de las baterías, la infraestructura eléctrica de cada país (puntos de recarga, electrolineras, etc…), las políticas que adopten los fabricantes, los gobiernos (subvenciones, etc…) entre otros. Se puede apreciar que tanto en la actualidad, como en las previsiones de futuro, España adoptará unas medidas más conservadoras, en comparación con países como Noruega (líder con una mayor proporción de vehículos eléctricos por habitante), China (líder en el mercado de las energías renovables y futuro líder en el mercado del VE), Alemania, Holanda… No obstante todos tienen el mismo objetivo; sustituir al 100% la flota de VCI por VEs para finales de 2050 y explotar las fuentes de energía renovables para obtener un ecosistema sostenible. Es evidente que al aumentar el número de vehículos eléctricos, aumenta la potencia demandada y que, al instalar más generación distribuida, se obtiene una mayor generación en diferentes puntos de la red. Por lo tanto, para poder llegar a cumplir con los objetivos antes mencionados, se necesitan analizar las redes eléctricas. Por ello, se ha seleccionado una red tipo del proyecto DISCERN [1]. Utilizando la herramienta “MATPOWER” se pueden estudiar los flujos de carga de las líneas y analizar su comportamiento ante variaciones de potencia y generación. Tras realizar las distintas simulaciones, tomando como referencia los días con una mayor y menor demanda eléctrica registrados en el BOE en la “resolución del 30 de diciembre de 2016 de la Dirección General de Política Energética y Minas” y las expectativas de crecimiento del vehículo eléctrico y de la generación distribuida, se puede observar que la red seleccionada va aumentando su índice de carga conforme van avanzando los años. Al analizar la evolución del vehículo eléctrico sin tener en cuenta la generación distribuida, se aprecia que para el año 2050, algunas líneas estarían bastante cargadas, sobrepasando los límites de seguridad y dejando poco margen entre la intensidad que circula y la máxima admisible que marca el límite térmico del conductor. Este problema se solventaría al introducir la evolución de la generación distribuida. En este caso, se observa que las líneas están mucho más descargadas y que la red soportaría sin problemas la potencia demandada para cualquier hora del año desde la actualidad (2017) hasta el 2050.Ingeniería Eléctric

    Using Mobile Devices for Improving Learning Outcomes and Teachers’ Professionalization

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    Teaching in higher education is changing due to the influence of technology. More and more technological tools are replacing old teaching methods and strategies. Thus, mobile devices are being positioned as a key tool for new ways of understanding educational practices. The present paper responds to a systematic review about the benefits that mobile devices have for university students’ learning. Using inclusion and exclusion criteria in theWeb of Science and Scopus databases, 16 articles were selected to argue why Mobile learning (Mlearning) has become a modern innovative approach. The results point to an improvement in students’ learning through Mlearning, factors that encourage the use of mobile devices in universities have been identified, and e ective mobile applications in improving teaching and learning processes have been presented. The inclusion of this methodology requires a new role for teachers, whose characterization is also specified

    Svq: a proposal for still image coding in mpeg 4 - snhc

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    A technique for efficient coding of homogeneous textures is presented here. The technique is based on the use of Stochastic Vector Quantization and provides very high compression with graceful degradation. To encode the image, a linear prediction filter is computed. Then, the prediction error is encoded using a Stochastic Vector Quantization approach. To decode the image, the prediction error is decoded first and then filtered as a whole using the prediction filter, thus avoiding the block effect found in conventional VQ. The approach has been proposed as a still image coding technique in MPEG 4 SNHC. Comparisons with the Video VM of MPEG 4 are also presentedPeer ReviewedPostprint (published version

    Le Gaz Journal: Genesis and defense of the interests of the gas industry 1857-1895.

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    La industria del gas tuvo sus inicios en Europa a finales del siglo XVIII. A partir de mediados de este siglo, los progresos científicos y tecnológicos se difundieron a través de tratados y publicaciones periódicas. Estas publicaciones evolucionaron de un enfoque generalista inicial a uno más especializado con el tiempo. La industria del gas no fue ajena a esta evolución, y desde la década de 1840 comenzaron a surgir las primeras revistas especializadas en gas. Estas revistas no solo sirvieron como vehículos para la difusión de los avances más destacados en el ámbito del gas, sino que también desempeñaron un papel crucial como centros de discusión y encuentro entre empresarios, ingenieros y consumidores. En este análisis, examinamos el papel desempeñado por la revista francesa Le Gaz en la defensa de los intereses del gas en el contexto de competencia con la electricidad desde 1857 hasta la década de 1890.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Predicted photoreflectance signatures on QD selective contacts for hot carrier solar cells

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    The CO2 emission of our present energy transformation processes, based mainly on burning fossil fuels, is possibly the main cause of global climatic change. The photovoltaic conversion of solar energy is a clean way of producing which for sustainability should (and most probably will) become a major source of electricity. The sun is a huge resource but relatively diluted and it is reasonable to expect that only high efficiency extraction can be cost effective for mass exploitation. New concepts are neccessary such as hot carrier solar cells

    Influence of glycerin and lecithin inclusion in the diet on liver characteristics and lipid fraction in the serum of brownegg laying hens at 55 week of age

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    The effects of the inclusion of raw glycerin (GLYC) and raw lecithin, in the diet (23 to 55 wk) on liver characteristics and various serum lipid fractions were studied in brown egg-laying hens at 55 wk of age. The control diets were based on corn, soybean meal, and 4% supplemental fat and contained 2,750 kcal AMEn/kg, 16.5% CP, and 0.73% digestible Lys. The diets were arranged as a 2 × 3 factorial with 2 levels of GLYC (0 and 7%) and 3 animal fat to lecithin ratios (4:0, 2:2, and 0:4%). Each treatment was replicated 8 times and the experimental unit was a cage with 10 hens. At 55 wk of age, 2 hens per cage replicate were randomly selected, weighed individually, and slaughtered by CO2 inhalation. Liver was immediately removed and weighed and the color recorded by spectrophotometry. In addition, blood samples from one bird per replicate were collected from the wing vein and the concentration of total cholesterol, low and high density lipoprotein cholesterol, and triglycerides were determined. The data were analyzed as a completely randomized design and the main effects of GLYC and lecithin content of the diet and the interactions were determined. No interactions between GLYC and lecithin content of the diets were detected for any of the variables studied. Liver characteristics and serum lipid traits were not affected by the inclusion of GLYC in the diet. The substitution of animal fat by lecithin, however, reduced the redness (a* 14.9 to 13.8) and yellowness (b* 8.60 to 7.20) values of the liver (P < 0.05) but did not affect the content of serum lipid fractions. It is concluded that the inclusion of GLYC and lecithin in the diet did not affect liver size or serum lipid fraction. However, the inclusion of lecithin reduced the a* and b* value of the live

    Effects of fiber inclusion on growth performance and nutrient digestibility of piglets reared under optimal or poor hygienic conditions

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    Two experiments were conducted to estimate the standardized ileal digestible (SID) Trp:Lys ratio requirement for growth performance of nursery pigs. Experimental diets were formulated to ensure that lysine was the second limiting AA throughout the experiments. In Exp. 1 (6 to 10 kg BW), 255 nursery pigs (PIC 327 × 1050, initially 6.3 ± 0.15 kg, mean ± SD) arranged in pens of 6 or 7 pigs were blocked by pen weight and assigned to experimental diets (7 pens/diet) consisting of SID Trp:Lys ratios of 14.7%, 16.5%, 18.4%, 20.3%, 22.1%, and 24.0% for 14 d with 1.30% SID Lys. In Exp. 2 (11 to 20 kg BW), 1,088 pigs (PIC 337 × 1050, initially 11.2 kg ± 1.35 BW, mean ± SD) arranged in pens of 24 to 27 pigs were blocked by average pig weight and assigned to experimental diets (6 pens/diet) consisting of SID Trp:Lys ratios of 14.5%, 16.5%, 18.0%, 19.5%, 21.0%, 22.5%, and 24.5% for 21 d with 30% dried distillers grains with solubles and 0.97% SID Lys. Each experiment was analyzed using general linear mixed models with heterogeneous residual variances. Competing heteroskedastic models included broken-line linear (BLL), broken-line quadratic (BLQ), and quadratic polynomial (QP). For each response, the best-fitting model was selected using Bayesian information criterion. In Exp. 1 (6 to 10 kg BW), increasing SID Trp:Lys ratio linearly increased (P 24.0%]) SID Trp:Lys ratio. For G:F, the best-fitting model was a BLL in which the maximum G:F was estimated at 20.4% (95% CI: [14.3%, 26.5%]) SID Trp:Lys. In Exp. 2 (11 to 20 kg BW), increasing SID Trp:Lys ratio increased (P < 0.05) ADG and G:F in a quadratic manner. For ADG, the best-fitting model was a QP in which the maximum ADG was estimated at 21.2% (95% CI: [20.5%, 21.9%]) SID Trp:Lys. For G:F, BLL and BLQ models had comparable fit and estimated SID Trp:Lys requirements at 16.6% (95% CI: [16.0%, 17.3%]) and 17.1% (95% CI: [16.6%, 17.7%]), respectively. In conclusion, the estimated SID Trp:Lys requirement in Exp. 1 ranged from 20.4% for maximum G:F to 23.9% for maximum ADG, whereas in Exp. 2 it ranged from 16.6% for maximum G:F to 21.2% for maximum ADG. These results suggest that standard NRC (2012) recommendations may underestimate the SID Trp:Lys requirement for nursery pigs from 11 to 20 kg BW

    Statistical Differences in Set Analysis in Badminton at the RIO 2016 Olympic Games

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    The aim of the present study was to determine statistical differences in a set of badminton competition matches in five different modalities with regard to competition level (Group Phase vs. Eliminatory Phase). Data from 453 sets (125 in men’s singles; 108 sets in women’s singles; 77 sets in men’s doubles; 73 in women’s doubles and 70 in mixed doubles) from the RIO 2016 Olympics Games were recorded and classified in two groups of variables to analyze variables related to match (5) and set (15). A descriptive analysis and univariate test (Mann–Whitney U) for non-parametric data were conducted. The results show in men’s and women’s singles all the variables related to match were higher in the Elimination Phase than in the Group Phase (p < 0.01). In Sets 1 and 3, the longest set duration, rally and average rally were found in the Elimination Phase than Group Stage (p < 0.05). In women’s singles, these differences were also recorded in Set 2. For doubles, the results are more stable among groups. Men’s doubles had a longer duration of the match and set (sets 1 and set 2) (p < 0.01), and also scored highest for average rally strokes (sets 1 3) (p < 0.05) and shuttles used in the Elimination Phase vs. the Group Phase along the match (p < 0.01). In women’s doubles, more shuttles were used in a match in the Elimination than in the Group Phase. Moreover, the same results are established for Set 2, including for average rally. Mixed doubles saw no match going to three sets. However, the greatest differences showed a longer rally and average rally being registered in the Elimination than in the Group Phase. In conclusion, the timing factors of the badminton singles and doubles games were different in the Elimination and Group Phases. This information may help players and coaches prepare and administer different types of workouts or, more specifically, competition schedules adapted to the characteristics of modern badminton

    Generation and Reactions of an Octacyclic Hindered Pyramidalized Alkene

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    Octacyclo[10.6.1.01,10.03,7.04,9.08,19.011,16.013,17]-nonadeca-5,8,14-triene (27), a hindered pyramidalized alkene, has been generated from a diiodide precursor. Contrary to the usual behavior of known pyramidalized alkenes, no Diels−Alder adducts were obtained from the present alkene when it was generated by different standard procedures in the presence of different dienes. However, products derived from the reduction, t-BuLi addition, condensation with the solvent, or dimerization were isolated from these reactions, depending on the conditions used to generate it. No [2 + 2] cross product among this pyramidalized alkene and tricyclo[3.3.1.03,7]non-3(7)-ene was formed when a mixture of the corresponding precursor diiodides was reacted with sodium amalgam. The analysis of selected geometrical and orbital parameters determined from quantum mechanical calculations indicates that the degree of pyramidalization of this alkene and its higher steric hindrance compared with other polycyclic pyramidalized alkenes may explain its peculiar reactivity
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