520 research outputs found

    The effects of energetic proton bombardment on polymeric materials: Experimental studies and degradation models

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    This report describes 3 MeV proton bombardment experiments on several polymeric materials of interest to NASA carried out on the Tandem Van De Graff Accelerator at the California Institute of Technology's Kellogg Radiation Laboratory. Model aromatic and aliphatic polymers such as poly(1-vinyl naphthalene) and poly(methyl methacrylate), as well as polymers for near term space applications such as Kapton, Epoxy and Polysulfone, have been included in this study. Chemical and physical characterization of the damage products have been carried out in order to develop a model of the interaction of these polymers with the incident proton beam. The proton bombardment methodology developed at the Jet Propulsion Laboratory and reported here is part of an ongoing study on the effects of space radiation on polymeric materials. The report is intended to provide an overview of the mechanistic, as well as the technical and experimental, issues involved in such work rather than to serve as an exhaustive description of all the results

    Pyramidal Stochastic Graphlet Embedding for Document Pattern Classification

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    This is the author accepted manuscript. The final version is available from IEEE via the DOI in this recordDocument pattern classification methods using graphs have received a lot of attention because of its robust representation paradigm and rich theoretical background. However, the way of preserving and the process for delineating documents with graphs introduce noise in the rendition of underlying data, which creates instability in the graph representation. To deal with such unreliability in representation, in this paper, we propose Pyramidal Stochastic Graphlet Embedding (PSGE). Given a graph representing a document pattern, our method first computes a graph pyramid by successively reducing the base graph. Once the graph pyramid is computed, we apply Stochastic Graphlet Embedding (SGE) for each level of the pyramid and combine their embedded representation to obtain a global delineation of the original graph. The consideration of pyramid of graphs rather than just a base graph extends the representational power of the graph embedding, which reduces the instability caused due to noise and distortion. When plugged with support vector machine, our proposed PSGE has outperformed the state-of-The-art results in recognition of handwritten words as well as graphical symbols.European Union Horizon 2020Ministerio de Educación, Cultura y Deporte, SpainRamon y Cajal FellowshipCERCA Program/Generalitat de Cataluny

    Graph-Based Deep Learning for Graphics Classification

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    This is the author accepted manuscript. The final version is available from IEEE via the DOI in this recordGraph-based representations are a common way to deal with graphics recognition problems. However, previous works were mainly focused on developing learning-free techniques. The success of deep learning frameworks have proved that learning is a powerful tool to solve many problems, however it is not straightforward to extend these methodologies to non euclidean data such as graphs. On the other hand, graphs are a good representational structure for graphical entities. In this work, we present some deep learning techniques that have been proposed in the literature for graph-based representations and we show how they can be used in graphics recognition problems.European Union Horizon 2020FPUMinisterio de Educación, Cultura y Deporte, SpainRamon y Cajal FellowshipCERCA Program/Generalitat de Cataluny

    Improving Information Retrieval in Multiwriter Scenario by Exploiting the Similarity Graph of Document Terms

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    This is the author accepted manuscript. The final version is available from IEEE via the DOI in this recordInformation Retrieval (IR) is the activity of obtaining information resources relevant to a questioned information. It usually retrieves a set of objects ranked according to the relevancy to the needed fact. In document analysis, information retrieval receives a lot of attention in terms of symbol and word spotting. However, through decades the community mostly focused either on printed or on single writer scenario, where the state-of-The-art results have achieved reasonable performance on the available datasets. Nevertheless, the existing algorithms do not perform accordingly on multiwriter scenario. A graph representing relations between a set of objects is a structure where each node delineates an individual element and the similarity between them is represented as a weight on the connecting edge. In this paper, we explore different analytics of graphs constructed from words or graphical symbols, such as diffusion, shortest path, etc. to improve the performance of information retrieval methods in multiwriter scenario.European Union Horizon 2020Ministerio de Educación, Cultura y Deporte, SpainFPUCERCA Programme/Generalitat de Cataluny

    Assessing the Effectiveness of a Gamified Social Network for Applying Privacy Concepts: An Empirical Study with Teens

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    [EN] The concept of privacy in online social networks (OSNs) is a challenge, especially for teenagers. Previous works deal with teaching about privacy using educational online content, and media literacy. However, these tools do not necessarily promote less risky behaviors, and do not allow the assessment of users' behavior after the learning period. Moreover, few research studies about the effects of social gamification have been performed for this population segment (i.e., teenagers). To address this problem in this article, we propose the use of gamification in an OSN called Pesedia to facilitate the teaching/learning process, and assess its effectiveness in promoting suitable privacy behaviors. We tested our proposal comparing teenagers' performance in two editions of a course about social networks, and privacy (with, and without gamification) for one month. We measured the impact of gamification in the participants' behaviors toward privacy concepts as a consequence of the privacy teaching/learning process, and the participants' engagement in the educational process. The results show that there are significant differences in participants' behavior regarding privacy, and engagement in the gamified social network. Moreover, there is also a significant difference in participants' engagement for the gamified male participants. The gamified social network proposed in this article may be relevant, and useful for educators who wish to develop, and enhance teenagers' privacy skills, or for a broader base of aspects related to the development of digital competences, and technology in education.This work was supported in part by the Spanish Government Project TIN2017-89156-R, and in part by the FPI under Grant BFS-2015-074498. (Corresponding author: Elena Del Vol.)Alemany-Bordera, J.; Del Val, E.; García-Fornes, A. (2020). Assessing the Effectiveness of a Gamified Social Network for Applying Privacy Concepts: An Empirical Study with Teens. IEEE Transactions on Learning Technologies. 13(4):777-789. https://doi.org/10.1109/TLT.2020.3026584S77778913

    Biochar versus hydrochar as growth media constituents for ornamental plant cultivation

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    [EN] Biochar and hydrochar have been proposed as novel materials for providing soilless growth media. However, much more knowledge is required before reliable advice can be given on the use of these materials for this purpose. Depending on the material and the technology applied (pyrolysis or hydrothermal carbonization), phytotoxicity and greenhouse gas emissions have been found for certain chars. In this study, our aim was to assess the feasibility of three chars as substrate constituents. We compared two biochars, one from forest waste and the other from olive mill waste, and a hydrochar from forest waste. We studied how chars affected substrate characteristics, plant performance, water economy and respiratory CO2 emission. Substrates containing biochar from forest waste showed the best characteristics, with good air/water relationships and adequate electrical conductivity. Those with biochar from olive mill waste were highly saline and, consequently, low quality. The substrates with hydrochar retained too much water and were poorly aerated, presenting high CO2 concentrations due to high respiratory activity. Plants performed well only when grown in substrates containing a maximum of 25 % biochar from forest waste or hydrochar. After analyzing the char characteristics, we concluded that biochar from forest waste could be safely used as a substrate constituent and is environmentally friendly when applied due to its low salinity and low CO2 emission. However, biochar from olive mill waste and hydrochar need to be improved before they can be used as substrate constituents.This study was funded by the Polytechnic University of Valencia (Projects on New Multidisciplinary Research; PAID-05-12). We thank Molly Marcus-McBride for supervising the English.Fornes Sebastiá, F.; Belda Navarro, RM. (2018). Biochar versus hydrochar as growth media constituents for ornamental plant cultivation. Scientia Agricola (Online). 75(4):304-312. https://doi.org/10.1590/1678-992X-2017-0062S304312754Abad, M., Noguera, P., & Burés, S. (2001). National inventory of organic wastes for use as growing media for ornamental potted plant production: case study in Spain. Bioresource Technology, 77(2), 197-200. doi:10.1016/s0960-8524(00)00152-8Bargmann, I., Martens, R., Rillig, M. C., Kruse, A., & Kücke, M. (2013). Hydrochar amendment promotes microbial immobilization of mineral nitrogen. Journal of Plant Nutrition and Soil Science, 177(1), 59-67. doi:10.1002/jpln.201300154Bargmann, I., Rillig, M. C., Buss, W., Kruse, A., & Kuecke, M. (2013). Hydrochar and Biochar Effects on Germination of Spring Barley. Journal of Agronomy and Crop Science, 199(5), 360-373. doi:10.1111/jac.12024Bedussi, F., Zaccheo, P., & Crippa, L. (2015). Pattern of pore water nutrients in planted and non-planted soilless substrates as affected by the addition of biochars from wood gasification. Biology and Fertility of Soils, 51(5), 625-635. doi:10.1007/s00374-015-1011-6Belda, R. M., Lidón, A., & Fornes, F. (2016). Biochars and hydrochars as substrate constituents for soilless growth of myrtle and mastic. Industrial Crops and Products, 94, 132-142. doi:10.1016/j.indcrop.2016.08.024Costello, R. C., & Sullivan, D. M. (2013). Determining the pH Buffering Capacity of Compost Via Titration with Dilute Sulfuric Acid. Waste and Biomass Valorization, 5(3), 505-513. doi:10.1007/s12649-013-9279-yFernandes, C., & Corá, J. E. (2004). Bulk density and relationship air/water of horticultural substrate. Scientia Agricola, 61(4), 446-450. doi:10.1590/s0103-90162004000400015Fornes, F., Belda, R. M., Carrión, C., Noguera, V., García-Agustín, P., & Abad, M. (2007). Pre-conditioning ornamental plants to drought by means of saline water irrigation as related to salinity tolerance. Scientia Horticulturae, 113(1), 52-59. doi:10.1016/j.scienta.2007.01.008Fornes, F., Belda, R. M., & Lidón, A. (2015). Analysis of two biochars and one hydrochar from different feedstock: focus set on environmental, nutritional and horticultural considerations. Journal of Cleaner Production, 86, 40-48. doi:10.1016/j.jclepro.2014.08.057Fornes, F., & Belda, R. M. (2017). Acidification with nitric acid improves chemical characteristics and reduces phytotoxicity of alkaline chars. Journal of Environmental Management, 191, 237-243. doi:10.1016/j.jenvman.2017.01.026Fornes, F., Belda, R. M., Fernández de Córdova, P., & Cebolla-Cornejo, J. (2017). Assessment of biochar and hydrochar as minor to major constituents of growing media for containerized tomato production. Journal of the Science of Food and Agriculture, 97(11), 3675-3684. doi:10.1002/jsfa.8227Fornes, F., Carrión, C., García-de-la-Fuente, R., Puchades, R., & Abad, M. (2010). Leaching composted lignocellulosic wastes to prepare container media: Feasibility and environmental concerns. Journal of Environmental Management, 91(8), 1747-1755. doi:10.1016/j.jenvman.2010.03.017GARCIADELAFUENTE, R., CARRION, C., BOTELLA, S., FORNES, F., NOGUERA, V., & ABAD, M. (2007). Biological oxidation of elemental sulphur added to three composts from different feedstocks to reduce their pH for horticultural purposes. Bioresource Technology, 98(18), 3561-3569. doi:10.1016/j.biortech.2006.11.008Genty, B., Briantais, J.-M., & Baker, N. R. (1989). The relationship between the quantum yield of photosynthetic electron transport and quenching of chlorophyll fluorescence. Biochimica et Biophysica Acta (BBA) - General Subjects, 990(1), 87-92. doi:10.1016/s0304-4165(89)80016-9Hoitink, H. A. J., Stone, A. G., & Han, D. Y. (1997). Suppression of Plant Diseases by Composts. HortScience, 32(2), 184-187. doi:10.21273/hortsci.32.2.184Libra, J. A., Ro, K. S., Kammann, C., Funke, A., Berge, N. D., Neubauer, Y., … Emmerich, K.-H. (2011). Hydrothermal carbonization of biomass residuals: a comparative review of the chemistry, processes and applications of wet and dry pyrolysis. Biofuels, 2(1), 71-106. doi:10.4155/bfs.10.81Mazuela, P., Salas, M. del C., & Urrestarazu, M. (2005). Vegetable Waste Compost as Substrate for Melon. Communications in Soil Science and Plant Analysis, 36(11-12), 1557-1572. doi:10.1081/css-200059054Méndez, A., Paz-Ferreiro, J., Gil, E., & Gascó, G. (2015). The effect of paper sludge and biochar addition on brown peat and coir based growing media properties. Scientia Horticulturae, 193, 225-230. doi:10.1016/j.scienta.2015.07.032Nieto, A., Gascó, G., Paz-Ferreiro, J., Fernández, J. M., Plaza, C., & Méndez, A. (2016). The effect of pruning waste and biochar addition on brown peat based growing media properties. Scientia Horticulturae, 199, 142-148. doi:10.1016/j.scienta.2015.12.012Sáez, J. A., Belda, R. M., Bernal, M. P., & Fornes, F. (2016). Biochar improves agro-environmental aspects of pig slurry compost as a substrate for crops with energy and remediation uses. Industrial Crops and Products, 94, 97-106. doi:10.1016/j.indcrop.2016.08.035Smith, B. R., Fisher, P. R., & Argo, W. R. (2004). Growth and Pigment Content of Container-grown Impatiens and Petunia in Relation to Root Substrate pH and Applied Micronutrient Concentration. HortScience, 39(6), 1421-1425. doi:10.21273/hortsci.39.6.1421Solaiman, Z. M., Murphy, D. V., & Abbott, L. K. (2011). Biochars influence seed germination and early growth of seedlings. Plant and Soil, 353(1-2), 273-287. doi:10.1007/s11104-011-1031-4Steiner, C., & Harttung, T. (2014). Biochar as a growing media additive and peat substitute. Solid Earth, 5(2), 995-999. doi:10.5194/se-5-995-2014Tian, Y., Sun, X., Li, S., Wang, H., Wang, L., Cao, J., & Zhang, L. (2012). Biochar made from green waste as peat substitute in growth media for Calathea rotundifola cv. Fasciata. Scientia Horticulturae, 143, 15-18. doi:10.1016/j.scienta.2012.05.018Vaughn, S. F., Eller, F. J., Evangelista, R. L., Moser, B. R., Lee, E., Wagner, R. E., & Peterson, S. C. (2015). Evaluation of biochar-anaerobic potato digestate mixtures as renewable components of horticultural potting media. Industrial Crops and Products, 65, 467-471. doi:10.1016/j.indcrop.2014.10.04

    An Active Learning Technique Enhanced with Electronic Polls

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    Only very few students answer questions like: “Did you understand this?”, “Do you have any question?”, etc. In this paper, we present an active learning technique that is based on the think-pair-share technique improved with the introduction of electronic polls to obtain anonymous instant feedback from the students. Electronic polls have been usually performed using Classroom Response Systems in the related literature, but these systems introduce a number of problems related to the excessive cost of the systems and the technical problems that they may cause to the instructors. Thus, we implement our active learning technique in an Interaction System that provides the benefits of supporting electronic polls but avoids the problems of Classroom Response Systems. We also present an example of how we applied our proposal to an Operating System lectures. Finally, we evaluate our proposal and demonstrate that the results we obtain are very similar to the ones obtained in the existing CRS literature without the problems that they introduce

    Using Reinforcement Learning to Solve a Dynamic Orienteering Problem with Random Rewards Affected by the Battery Status

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    [EN] This paper discusses an orienteering optimization problem where a vehicle using electric batteries must travel from an origin depot to a destination depot while maximizing the total reward collected along its route. The vehicle must cross several consecutive regions, with each region containing different types of charging nodes. A charging node has to be selected in each region, and the reward for visiting each node¿in terms of a `satisfactory¿ charging process¿is a binary random variable that depends upon dynamic factors such as the type of charging node, weather conditions, congestion, battery status, etc. To learn how to efficiently operate in this dynamic environment, a hybrid methodology combining simulation with reinforcement learning is proposed. The reinforcement learning component is able to make informed decisions at each stage, while the simulation component is employed to validate the learning process. The computational experiments show how the proposed methodology is capable of design routing plans that are significantly better than non-informed decisions, thus allowing for an efficient management of the vehicle¿s battery under such dynamic conditions.This work was partially funded by the European Commission projects SUN (HORIZONCL4-2022-HUMAN-01-14-101092612), and AIDEAS (HORIZON-CL4-2021-TWIN-TRANSITION-01-07-101057294).Juan, AA.; Marugan, CA.; Ahsini, Y.; Fornes, R.; Panadero, J.; Martín, XA. (2023). Using Reinforcement Learning to Solve a Dynamic Orienteering Problem with Random Rewards Affected by the Battery Status. Batteries. 9(8). https://doi.org/10.3390/batteries90804169

    Multi-dimensional adaptation in MAS organizations

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    © 2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Organization adaptation requires determining the consequences of applying changes not only in terms of the benefits provided but also measuring the adaptation costs as well as the impact that these changes have on all of the components of the organization. In this paper, we provide an approach for adaptation in multiagent systems based on a multidimensional transition deliberation mechanism (MTDM). This approach considers transitions in multiple dimensions and is aimed at obtaining the adaptation with the highest potential for improvement in utility based on the costs of adaptation. The approach provides an accurate measurement of the impact of the adaptation since it determines the organization that is to be transitioned to as well as the changes required to carry out this transition. We show an example of adaptation in a service provider network environment in order to demonstrate that the measurement of the adaptation consequences taken by the MTDM improves the organization performance more than the other approaches.Manuscript received January 2, 2012; revised July 26, 2012; accepted August 7, 2012. Date of publication August 31, 2012; date of current version April 16, 2013. This work was supported in part by projects TIN2008-04446 and TIN2009-13839-C03-01. J. M. Alberola received a Grant from Ministerio de Ciencia e Innovacion de Espana (AP2007-00289). This paper was recommended by Associate Editor J. Huang.Alberola Oltra, JM.; Julian Inglada, VJ.; García-Fornes, A. (2013). Multi-dimensional adaptation in MAS organizations. IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics. 43(2):622-633. https://doi.org/10.1109/TSMCB.2012.2213592S62263343

    Using Reinforcement Learning to Solve a Dynamic Orienteering Problem with Random Rewards Affected by the Battery Status

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    This paper discusses an orienteering optimization problem where a vehicle using electric batteries must travel from an origin depot to a destination depot while maximizing the total reward collected along its route. The vehicle must cross several consecutive regions, with each region containing different types of charging nodes. A charging node has to be selected in each region, and the reward for visiting each node-in terms of a 'satisfactory' charging process-is a binary random variable that depends upon dynamic factors such as the type of charging node, weather conditions, congestion, battery status, etc. To learn how to efficiently operate in this dynamic environment, a hybrid methodology combining simulation with reinforcement learning is proposed. The reinforcement learning component is able to make informed decisions at each stage, while the simulation component is employed to validate the learning process. The computational experiments show how the proposed methodology is capable of design routing plans that are significantly better than non-informed decisions, thus allowing for an efficient management of the vehicle's battery under such dynamic conditions
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