864 research outputs found
Understanding and Predicting Image Memorability at a Large Scale
Progress in estimating visual memorability has been limited by the small scale and lack of variety of benchmark data. Here, we introduce a novel experimental procedure to objectively measure human memory, allowing us to build LaMem, the largest annotated image memorability dataset to date (containing 60,000 images from diverse sources). Using Convolutional Neural Networks (CNNs), we show that fine-tuned deep features outperform all other features by a large margin, reaching a rank correlation of 0.64, near human consistency (0.68). Analysis of the responses of the high-level CNN layers shows which objects and regions are positively, and negatively, correlated with memorability, allowing us to create memorability maps for each image and provide a concrete method to perform image memorability manipulation. This work demonstrates that one can now robustly estimate the memorability of images from many different classes, positioning memorability and deep memorability features as prime candidates to estimate the utility of information for cognitive systems. Our model and data are available at: http://memorability.csail.mit.edu.National Science Foundation (U.S.) (Grant 1532591)McGovern Institute for Brain Research at MIT. Neurotechnology (MINT) ProgramMassachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory. MIT Big Data InitiativeGoogle (Firm)Xerox Corporatio
Pressed and sintered AISI 4140 PM low alloy steel from gas atomised powders
This paper is based on a presentation at Euro PM 2012 organised by EPMA in Basel, Switzerland on 16–19 September 2012In conventional PM of low alloy steels various alloying routes are used (fully prealloyed powders, diffusion alloying, elemental powders), but always using powders that allow uniaxial pressing, i.e. acceptable compressibility and flow. Fully prealloyed gas atomised powders (including carbon content) have never been an option because their small size. These powders need to be granulated before being uniaxially pressed and the binder used in the granulating process must be eliminated in the first steps of the sintering cycle. Such a processing route is proposed and initial results presented. A potential advantage of the process is that a low particle size can activate the sintering performance, bringing energy and cost savings over the full process cycle.Publicad
Multi-utility Learning: Structured-output Learning with Multiple Annotation-specific Loss Functions
Structured-output learning is a challenging problem; particularly so because
of the difficulty in obtaining large datasets of fully labelled instances for
training. In this paper we try to overcome this difficulty by presenting a
multi-utility learning framework for structured prediction that can learn from
training instances with different forms of supervision. We propose a unified
technique for inferring the loss functions most suitable for quantifying the
consistency of solutions with the given weak annotation. We demonstrate the
effectiveness of our framework on the challenging semantic image segmentation
problem for which a wide variety of annotations can be used. For instance, the
popular training datasets for semantic segmentation are composed of images with
hard-to-generate full pixel labellings, as well as images with easy-to-obtain
weak annotations, such as bounding boxes around objects, or image-level labels
that specify which object categories are present in an image. Experimental
evaluation shows that the use of annotation-specific loss functions
dramatically improves segmentation accuracy compared to the baseline system
where only one type of weak annotation is used
Do European agroforestry systems enhance biodiversity and ecosystem services? A meta-analysis
Agroforestry has been proposed as a sustainable agricultural system over conventional agriculture and forestry, conserving biodiversity and enhancing ecosystem service provision while not compromising productivity. However, the available evidence for the societal benefits of agroforestry is fragmented and does often not integrate diverse ecosystem services into the assessment. To upscale existing case-study insights to the European level, we conducted a meta-analysis on the effects of agroforestry on ecosystem service provision and on biodiversity levels. From 53 publications we extracted a total of 365 comparisons that were selected for the meta-analysis. Results revealed an overall positive effect of agroforestry (effect size = 0.454, p < 0.01) over conventional agriculture and forestry. However, results were heterogeneous, with differences among the types of agroforestry practices and ecosystem services assessed. Erosion control, biodiversity, and soil fertility are enhanced by agroforestry while there is no clear effect on provisioning services. The effect of agroforestry on biomass production is negative. Comparisons between agroforestry types and reference land-uses showed that both silvopastoral and silvoarable systems increase ecosystem service provision and biodiversity, especially when compared with forestry land. Mediterranean tree plantation systems should be especially targeted as soil erosion could be highly reduced while soil fertility increased. We conclude that agroforestry can enhance biodiversity and ecosystem service provision relative to conventional agriculture and forestry in Europe and could be a strategically beneficial land use in rural planning if its inherent complexity is considered in policy measures
Tuning and comparison of design concepts applying Pareto optimality. A case study of Cholette bioreactor
[EN] The linear control PI (D) and its variants are control structures (design concepts) that are still used in industrial processes. The control engineer will prefer one over another according to a desired tradeoff among complexity and performance indices. Given that this exchange might be in conflict, an analisis using multiobjective optimisation tools could be interesting. With this perspective, different Pareto fronts from different design concetps are compared, enabling a global, and not punctual, performance comparison. In this work a global methodology for comparing design concepts in dfferent stages was developed. The first step was to establish a region of stability. In the second stage, the stability region was considered as a search space for the multiobjective optimization process, approximating a Pareto set and front. In the third stage, a multicriteria analysis of the Pareto fronts was carried out, together with the simulation in the time domain for the output and control signals. As case study to validate this proposal the Cholette’s biorreactor was selected. The proposed methodology allows a better understanding of a conceptual solution, justifies and determines the use of a design concept thus meeting the needs of the designer.[ES] El control lineal PI(D) y sus variantes, son estructuras de control (conceptos de diseño) que actualmente se siguen utilizando en procesos industriales. La elección de una estructura de control sobre otra reside en el intercambio de prestaciones entre complejidad y rendimiento. Dado que este intercambio de prestaciones normalmente estará en conflicto, un análisis desde el punto de vista multiobjetivo puede ser de interés. Desde tal perspectiva, se analizan frentes de Pareto de diferentes conceptos de diseño, con lo que se realiza una comparación global y no puntual de tales conceptos. En este trabajo se plantea una propuesta metodológica para dicha comparación en diferentes etapas. La primera, fue establecer una región de estabilidad. En la segunda etapa se consideró la región de estabilidad como espacio de búsqueda para el proceso de optimización multiobjetivo calculando un conjunto y frente de Pareto. En la tercera etapa se realizó un análisis multicriterio de los frentes de Pareto, junto con la simulación en el dominio del tiempo para las señales de salida y de control. Como caso de estudio para validar la propuesta se ha elegido el biorreactor de Cholette que presenta diferentes condiciones de operación. 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A social-ecological analysis of ecosystem services supply and trade-offs in European wood-pastures
Wood-pastures are complex social-ecological systems (SES), which are the product of long-term interaction between society and its surrounding landscape. Traditionally characterized by multifunctional low-intensity management that enhanced a wide range of ecosystem services (ES), current farm management has shifted toward more intensive farm models. This study assesses the supply of ES in four study areas dominated by managed wood-pastures in Spain, Sweden, and Romania. On the basis of 144 farm surveys and the use of multivariate techniques, we characterize farm management and structure in the study areas and identify the trade-offs in ES supply associated with this management. We link these trade-offs to multiple factors that characterize the landholding: economic, social, environmental, technological, and governance. Finally, we analyze how landholders' values and perspectives have an effect on management decisions. Results show a differentiated pattern of ES supply in the four study areas. We identified four types of trade-offs in ES supply that appear depending on what is being promoted by the farm management and that are associated with different dimensions of wood-pasture management: productivity-related trade-offs, crop production-related trade-offs, multifunctionality-related trade-offs, and farm accessibility-related trade-offs. These trade-offs are influenced by complex interactions between the properties of the SES, which have a direct influence on landholders' perspectives and motivations. The findings of this paper advance the understanding of the dynamics between agroecosystems and society and can inform system-based agricultural and conservation policies
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