排序方式: 共有69条查询结果,搜索用时 15 毫秒
1.
Axel Carlier Amaia Salvador Ferran Cabezas Xavier Giro-i-Nieto Vincent Charvillat Oge Marques 《Multimedia Tools and Applications》2016,75(23):15901-15928
There has been a growing interest in applying human computation – particularly crowdsourcing techniques – to assist in the solution of multimedia, image processing, and computer vision problems which are still too difficult to solve using fully automatic algorithms, and yet relatively easy for humans. In this paper we focus on a specific problem – object segmentation within color images – and compare different solutions which combine color image segmentation algorithms with human efforts, either in the form of an explicit interactive segmentation task or through an implicit collection of valuable human traces with a game. We use Click’n’Cut, a friendly, web-based, interactive segmentation tool that allows segmentation tasks to be assigned to many users, and Ask’nSeek, a game with a purpose designed for object detection and segmentation. The two main contributions of this paper are: (i) We use the results of Click’n’Cut campaigns with different groups of users to examine and quantify the crowdsourcing loss incurred when an interactive segmentation task is assigned to paid crowd-workers, comparing their results to the ones obtained when computer vision experts are asked to perform the same tasks. (ii) Since interactive segmentation tasks are inherently tedious and prone to fatigue, we compare the quality of the results obtained with Click’n’Cut with the ones obtained using a (fun, interactive, and potentially less tedious) game designed for the same purpose. We call this contribution the assessment of the gamification loss, since it refers to how much quality of segmentation results may be lost when we switch to a game-based approach to the same task. We demonstrate that the crowdsourcing loss is significant when using all the data points from workers, but decreases substantially (and becomes comparable to the quality of expert users performing similar tasks) after performing a modest amount of data analysis and filtering out of users whose data are clearly not useful. We also show that – on the other hand – the gamification loss is significantly more severe: the quality of the results drops roughly by half when switching from a focused (yet tedious) task to a more fun and relaxed game environment. 相似文献
2.
Testing of carbon supported Pd-Pt electrocatalysts for methanol electrooxidation in direct methanol fuel cells 总被引:1,自引:0,他引:1
Francisco Alcaide Garbiñe ÁlvarezPere L. Cabot Hans-Jürgen GrandeOscar Miguel Amaia Querejeta 《International Journal of Hydrogen Energy》2011,36(7):4432-4439
In the present work, a detailed characterization of the electrochemical behavior of carbon supported Pd-Pt electrocatalysts toward CO and methanol electrooxidation in direct methanol fuel cells is reported. Technical electrodes containing an ionomer in their catalyst layer were prepared for this purpose. CO and methanol electrooxidation reactions were used as test reactions to compare the electrocatalytic behavior of bimetallic supported nanoparticles in acidic liquid electrolyte and in solid polymer electrolyte (real fuel cell operating conditions). Experimental results in both environments are consistent and show that the electrochemical behavior of carbon supported Pd-Pt depends on their composition, giving the best performance in direct methanol single fuel cell with a Pd:Pt atomic ratio of 25:75 in the catalyst. 相似文献
3.
The evolution of smart vehicles has widened the application opportunities for vehicular ad hoc networks. In this context, the routing issue is still one of the main challenges regarding to the performance of the network. Although there are multiple ad hoc routing proposals, the traditional general-purpose approaches do not fit the distinctive properties of vehicular network environments. New routing strategies must complement the existing protocols to improve their performance in vehicular scenarios. This paper introduces a novel intelligent routing technique that makes decisions in order to adaptively adjust its operation and obtain a global benefit. The nodes sense the network locally and collect information to feed the cognitive module which will select the best routing strategy, without the need of additional protocol message dissemination or convergence mechanism. 相似文献
4.
Peroxisome proliferators comprise a heterogeneous group of compounds known for their ability to cause massive proliferation of peroxisomes and liver carcinogenesis in rodents. In recent years it has become evident that other animals may be threatened by peroxisome proliferators, in particular aquatic organisms living in coastal and estuarine areas. These animals are exposed to a variety of pollutants of industrial, agricultural and urban origin which are potential peroxisome proliferators. Both laboratory and field studies have shown that phthalate ester plasticizers, PAHs and oil derivatives, PCBs, certain pesticides, bleached kraft pulp and paper mill effluents, alkylphenols and estrogens provoke peroxisome proliferation in different fish or bivalve mollusc species. The response appears to be mediated by peroxisome-proliferator activated receptors, members of the nuclear receptor family, recently cloned in fish. Based on these results it is proposed that peroxisome proliferation could be used as a biomarker of exposure to a variety of pollutants in environmental pollution assessment. This is illustrated by a case study in which mussels, used worldwide as sentinels of environmental pollution, were transplanted from reference to contaminated areas and vice versa. In mussels native to an area polluted with PAHs and PCBs, peroxisomal acyl-CoA oxidase (AOX) activity and peroxisomal volume density were 2-3 fold and 5-fold higher, respectively, compared to the reference site. When animals were transplanted to the polluted station, with increased concentration of organic xenobiotics, a concomitant significant increase of AOX was recorded. Conversely, in animals transplanted to the cleaner station, AOX activity and peroxisomal volume density decreased significantly. These results indicate that peroxisome proliferation is a rapid (i.e., two days) and reversible response to pollution in mussels. Before peroxisome proliferation can be implemented as a biomarker in biomonitoring programs, a well-defined protocol should be established and validated in intercalibration and quality assurance programmes. Furthermore, the influence of biotic and abiotic factors, some of which are known to affect peroxisome proliferation (season, tide level, interpopulation and interindividual variability), should be taken into consideration. The possible hepatocarcinogenic effects as well as the potential adverse effects on reproduction, development, and growth of peroxisome proliferators are unknown in aquatic organisms, thus providing a challenge for future investigations. 相似文献
5.
A. Centeno V.G. Rocha B. Alonso A. Fernández C.F. Gutierrez-Gonzalez R. Torrecillas A. Zurutuza 《Journal of the European Ceramic Society》2013,33(15-16):3201-3210
A simple, fast and upscalable method is described to produce graphene/alumina (G/Al2O3) composites by spark plasma sintering (SPS) with a significant improvement on both mechanical and electrical properties of monolithic Al2O3. Graphene oxide (GO) was mixed with Al2O3 using a colloidal method obtaining an excellent dispersion of GO in the alumina matrix. The material was consolidated by SPS that allowed, in one-step, the in situ reduction of the GO during the sintering process. A detailed Raman analysis was found to be very useful to study the orientation of the graphene in the composite and to evaluate and optimise its thermal reduction. Graphene platelets acted as elastic bridges avoiding crack propagation and providing this material with a crack bridging reinforcement mechanism. A very low graphene loading (0.22 wt%) led to a 50% improvement on the mechanical properties of the alumina and to an increase of the electrical conductivity up to eight orders of magnitude. 相似文献
6.
C sar Mart n-G mez Amaia Zuazua-Ros Javier Bermejo-Busto Enrique Baquero Rafael Miranda Cristina Sanz 《建筑学研究前沿(英文版)》2019,8(1):17-31
The strategies for thermal regulation and environmental control found in nature are countless. In this article, a parallelism between animals and building energy systems is defined in order to identify and emphasize the immediate opportunities that biomimicry offers for future research. The motivation was the need to find alternative solutions to tackle problems mainly in the efficiency of heating, ventilation and cooling systems. Due to the wide range of possibilities offered by animals, this study is largely limited to the strategies that cold-blooded animals have developed through evolutionary adaptation to the environment. The method used for the analysis is based on a solution-based approach. Firstly, different animal thermoregulation strategies are defined (biologicaldomain). Then the strategy is analyzed and classified into three categories. This classification is essential in order to formulate the parallelism with building systems (transfer phase). The final step is to identify the potential implementation (technologicaldomain). This approach has been seen to be useful in creating new research opportunities based on biomimicry. In addition, suitable solutions arising from multidisciplinary team research are presented as promising answers to the challenges that building energy systems face nowadays. 相似文献
7.
María J. Unzu Harold A. S. Schoonbrood Jos M. Asua Amaia Montoya Goi David C. Sherrington Katrin Sthler Karl-Heinz Goebel Klaus Tauer Marie Sjberg Krister Holmberg 《应用聚合物科学杂志》1997,66(9):1803-1820
Several polymerizable surfactants (surfmers) have been used in the semi-continuous emulsion copolymerization of styrene, butyl acrylate, and acrylic acid. Three of the (anionic) surfmers (sodium 11-crotonoyl undecan-1-yl sulfate, sodium 11-methacryloyl undecan-1-sulfate, and sodium sulfopropyl tetradecyl maleate) were prepared in house with purities between 53 and 82%. Physicochemical properties such as the critical micelle concentration, the adsorption isotherm, and the specific adsorption area were determined. The surfmers were then used with constant addition profiles in semicontinuous reactions, and the instantaneous conversions of the main monomers determined. The particle size, amount of coagulum, surface tension, and stability against electrolyte solutions of the latices were evaluated. Films were cast of some of the latices, and the visual appearance and water adsorption were assessed. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 183–1820, 1997 相似文献
8.
Amaia Bastero Aurora Ruiz Carmen Claver Antonio Bella Barbara Milani Beln Moreno‐Lara FlixA. Jaln BlancaR. Manzano 《Advanced Synthesis \u0026amp; Catalysis》2005,347(6):839-846
The CO/tert‐butylstyrene/ethylene terpolymerization catalyzed by Pd‐(N‐N′) complexes was studied. The results evidence that the olefin preferentially inserted in the terpolymer chain is strictly related to the nature of the nitrogen ligand, mainly to its steric constraints, and not to the kind of ligand. Indeed, slight variations in the backbone of the nitrogen ligands coordinated to palladium allow for the synthesis of terpolymers with a controlled composition. 相似文献
9.
Zurutuza Irati Isasti Nerea Detemple Eric Schwinn Volker Mohrbacher Hardy Uranga Pello 《Metallurgical and Materials Transactions A》2022,53(4):1529-1539
Metallurgical and Materials Transactions A - This work has focused on the study of hot working behavior of boron high strength steels microalloyed with different combinations of Nb and/or Mo. The... 相似文献
10.
Flora Faleschini Amaia Santamaria Mariano Angelo Zanini José-Tomás San José Carlo Pellegrino 《Materials and Structures》2017,50(3):170
This paper deals with the bond between steel reinforcement and recycled aggregate concrete, including Electric arc furnace (EAF) slag as full replacement of natural coarse aggregates. Pull-out tests were carried out according to RILEM standard on specimens made with six concrete mixtures, characterized by different w/c ratios and types of aggregates. Plain and ribbed steel reinforcement bars were used to observe the influence of steel roughness. Experimental bond-slip relationships were analyzed, and results show similar bond mechanisms between the reference and EAF concrete specimens. Significant bond strength enhancement is observed in concretes with low w/c ratio, when EAF slag is used as recycled coarse aggregate. Experimental results in terms of bond strength were also compared to analytical predictions, obtained with empirical formulations. 相似文献