14,455 research outputs found

    A comparative study of selected sorbents for sampling of aromatic VOCs from indoor air

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    Indoor air canbecome pollutedwith VOCs, and understanding the factors which affect adsorption of VOCs from indoor air is important for: (i) the accurate measurement of VOCs, and (ii) to apply mitigation strategies when high analyte concentrations are measured. In this study four VOCs (toluene, ethylbenzene, cumene and dichlorobenzene) were generated as a constant and controlled polluted air stream of VOCs from a dynamic atmospheric chamber. The effects of relative humidity, and sampling ïŹ‚ow rate, on adsorption onto Tenax TA and the relatively new silica adsorbents SBA-15 or MCM-41 were studied

    Pension Fund Capitalism and Financial Crisis. IHS Political Science Series 126, December 2011

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    Basic public pension schemes and cut backs in earnings-related public pensions led to an increasing role of supplementary pensions such as pension funds for old-age incomes. In addition to demographic changes that challenge public pensions, private pensions face financial market risks. To what extent are the scope of pension fund capitalism and the impact of financial crises on pension funds related to different institutional arrangements? Given that different production regimes reflect different pension systems, we expect systematic diversities with regard to the public-private pension mix and the specific design of supplementary pensions. These varieties should be mirrored in different forms of vulnerability of pension funds to financial market crises. We hypothesize a higher scope of pension fund capitalism and vulnerability to financial market crises in countries with predominant market-based coordination mechanisms and short term strategies on financial markets (i.e. Liberal Market Economies)

    Unmasking Clever Hans Predictors and Assessing What Machines Really Learn

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    Current learning machines have successfully solved hard application problems, reaching high accuracy and displaying seemingly "intelligent" behavior. Here we apply recent techniques for explaining decisions of state-of-the-art learning machines and analyze various tasks from computer vision and arcade games. This showcases a spectrum of problem-solving behaviors ranging from naive and short-sighted, to well-informed and strategic. We observe that standard performance evaluation metrics can be oblivious to distinguishing these diverse problem solving behaviors. Furthermore, we propose our semi-automated Spectral Relevance Analysis that provides a practically effective way of characterizing and validating the behavior of nonlinear learning machines. This helps to assess whether a learned model indeed delivers reliably for the problem that it was conceived for. Furthermore, our work intends to add a voice of caution to the ongoing excitement about machine intelligence and pledges to evaluate and judge some of these recent successes in a more nuanced manner.Comment: Accepted for publication in Nature Communication

    3D Object Class Detection in the Wild

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    Object class detection has been a synonym for 2D bounding box localization for the longest time, fueled by the success of powerful statistical learning techniques, combined with robust image representations. Only recently, there has been a growing interest in revisiting the promise of computer vision from the early days: to precisely delineate the contents of a visual scene, object by object, in 3D. In this paper, we draw from recent advances in object detection and 2D-3D object lifting in order to design an object class detector that is particularly tailored towards 3D object class detection. Our 3D object class detection method consists of several stages gradually enriching the object detection output with object viewpoint, keypoints and 3D shape estimates. Following careful design, in each stage it constantly improves the performance and achieves state-ofthe-art performance in simultaneous 2D bounding box and viewpoint estimation on the challenging Pascal3D+ dataset

    Image collection pop-up: 3D reconstruction and clustering of rigid and non-rigid categories

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    © 20xx 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.This paper introduces an approach to simultaneously estimate 3D shape, camera pose, and object and type of deformation clustering, from partial 2D annotations in a multi-instance collection of images. Furthermore, we can indistinctly process rigid and non-rigid categories. This advances existing work, which only addresses the problem for one single object or, if multiple objects are considered, they are assumed to be clustered a priori. To handle this broader version of the problem, we model object deformation using a formulation based on multiple unions of subspaces, able to span from small rigid motion to complex deformations. The parameters of this model are learned via Augmented Lagrange Multipliers, in a completely unsupervised manner that does not require any training data at all. Extensive validation is provided in a wide variety of synthetic and real scenarios, including rigid and non-rigid categories with small and large deformations. In all cases our approach outperforms state-of-the-art in terms of 3D reconstruction accuracy, while also providing clustering results that allow segmenting the images into object instances and their associated type of deformation (or action the object is performing).Postprint (author's final draft

    Six Steps to a Healthier Ambient Ozone Policy

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    EPA appears likely to tighten the ambient ozone standard, even as many areas of the country are having great difficulties meeting the current standard. This paper offers an analysis of potential regulatory, administrative, and legislative initiatives for reducing the costs of meeting ozone standards. The detailed analysis of these initiatives is organized into six steps: (i) acknowledge mistakes and adapt to new knowledge; (ii) rehabilitate EPA's Title I Program; (iii) build on the best ideas; (iv) clarify and change the Clean Air Act; (v) educate the public; and (vi) fund research. EPA can go a long way to make its programs more efficient and effective without changes in the Clean Air Act; indeed, a number of its current initiatives show promise. But it must do more. Congress can help, too, by giving EPA the statutory guidance and freedom it needs to improve the program.

    Indoor Air Quality Design and Control in Low-Energy Residential Buildings: Current challenges, selected case studies and innovative solutions covering indoor air quality, ventilation design and control in residences. International Energy Agency Report, Energy in Buildings and Communities Programme, IEA EBC Annex 68

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    The objective of Subtask 4 in the IEA EBC Annec 68 was to integrate knowledge and results from remaining Subtasks and present them in the context with current knowledge. The focus of the Subtask 4 was on practitioners dealing with ensuring high Indoor Air Quality (IAQ) in modern low-energy residences, the demands and challenges they meet during daily work. This especially includes architects and ventilation designers, facility managers, property developers and employees of public authorities. This publication is a result if Subtask 4’s work. It brings a collection of 24 “case studies” related to IAQ design and control in Low-Energy Residential Buildings. By a “case study” we mean a real life construction project, laboratory investigation or a simulation study that provides innovative approach. The case studies were selected to give the practitioners new insigts, inspiration and motivation to go along new paths leading to sustainable and comfortable homes of the future. The report is organized into three main chapters: “Ways to design residential ventilation in the future” and “Towards better performance and user satisfaction”. The descriptions of case studies are accompanied by “lessons learned” sections aiming directly at practical utilization of results as well as recommended future reading section providing the most important references
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