1,622 research outputs found

    A simple and efficient face detection algorithm for video database applications

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    The objective of this work is to provide a simple and yet efficient tool to detect human faces in video sequences. This information can be very useful for many applications such as video indexing and video browsing. In particular the paper focuses on the significant improvements made to our face detection algorithm presented by Albiol, Bouman and Delp (see IEEE Int. Conference on Image Processing, Kobe, Japan, 1999). Specifically, a novel approach to retrieve skin-like homogeneous regions is presented, which is later used to retrieve face images. Good results have been obtained for a large variety of video sequences.Peer ReviewedPostprint (published version

    The Critical Aggregation Concentration of ß-Lactoglobulin-Based Fibril Formation

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    The critical aggregation concentration (CAC) for fibril formation of ß-lactoglobulin (ß-lg) at pH 2 was determined at 343, 353, 358, 363, and 383 K using a Thioflavin T assay and was approximately 0.16 wt%. The accuracy of the CAC was increased by measuring the conversion into fibrils at different stirring speeds. The corresponding binding energy per mol, as determined from the CAC, was 13 RT (~40 kJ mol¿1) for the measured temperature range. The fact that the CAC was independent of temperature within the experimental error indicates that the fibril formation of ß-lg at pH 2 and the measured temperature range is an entropy-driven process

    Ab Initio Calculations and Mechanistic Analyses of Optical Activity of Organic Molecules with Extended Chromophores

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    Molecular orbital calculation of electronic transition energies and oscillator and rotatory strengths in the random phase approximation (RPA) is reviewed, and it is outlined how the three mechanisms contained in Kirkwood\u27s theory of optical rotatory power and other features of the excitations may be extracted from such calculations. The method is applied to the chiroptical properties of cis,trans-(1,3)-cyclooctadiene and bicyclo[2.2.1Jhept- 5-en-2-one, both of which contain an extended chromophoric system. The results for the diene support Sandstrom\u27s assignment of P helicity to the (-)-enantiomer despite the prediction of simple Diene Rule, and structural and spectral similarities to (-)-trans-cyclooctene are strong. The enone calculations confirm the model assumptions about the predominance of a ,u-m rotatory strength mechanism whereas the analysis of the bond eontributions and of the transition moment direction differs significantly from the assumptions governing the chirality rule of Schippers and Dekkers and other models

    Embedding Ethical Impact Assessment in Nanosafety Decision Support

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    Nanotechnology is a key enabling technology, which is developing fast and influences many aspects of life. Nanomaterials are already included in a broad range of products and industrial sectors. Nanosafety issues are still a matter of concern for policy makers and stakeholders, but currently, there is no platform where all stakeholders can meet and discuss these issues. A comprehensive overview of all the issues in one single dashboard presenting the output of a decision support system is also lacking. This article outlines a strategy for developing one innovative part of a modular decision support system, designed to support the work of a new Risk Governance Council (RGC) for nanomaterials which will be established through the combined efforts of the GOV4NANO, NANORIGO, and RiskGONE H2020 projects. This new module will consist of guidelines for Ethical Impact Assessment (EIA) for nanomaterials and nanoenabled products. This article offers recommendations for adapting the European Committee for Standardization (CEN) prestandard on Ethical Impact Assessment CWA (CEN Workshop Agreement) 17145-2:2017 (E), to fit into the more-encompassing decision support system for risk governance of nanomaterials within the RiskGONE project

    Op weg naar Park Essenburg : advies aan Bewonersgroep ProGroen Rotterdam

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    Bewonersgroep ProGroen in Rotterdam is voor het behoud van een miskende groenstrook van circa twaalf hectare tussen de spoordijk en Essenburgsingel. Ze wil dat het gebied in de deelgemeente Delfshaven het groene en duurzame karakter behoudt en dat het in de toekomst goed bruikbaar is en blijft voor alle mensen uit de buurt en de stad. De Wetenschapswinkel ziet voor ProGroen de opgave weggelegd om aan te tonen dat de strook een waardevol groenelement is in de stad. Het park draagt bij aan de sociale cohesie: het vergroot het aantal ontmoetingsplekken in de wijk, biedt laagdrempelige aanleidingen om contact te leggen en motiveert bewoners te investeren in relaties in de buurt. Daarnaast biedt het park de wijkbewoners nieuwe mogelijkheden om in contact te komen met groen, met natuur. De eerste concrete invulling van het park is PlukTuin Essenburg RFC. Deze PlukTuin, een buurttuin, wordt aangelegd op een voormalige parkeerplaats. Opzet is dat bewoners de PlukTuin zelf aanleggen en onderhoude

    Impact of alternate wetting and drying irrigation on rice growth and resource-use efficiency

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    Crop-based irrigationRiceFertilizersNitrogenRainCrop yieldPercolationSeepagePaddy fieldsExperiments

    A polar surface eddy obscured by thermal stratification

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    Mesoscale and submesoscale eddies play an important role in the distribution of heat and biogeochemical properties throughout the global oceans. Such eddies are important in the Arctic Ocean, particularly in the frontal regions, but are difficult to detect using traditional satellite‐based methods. Here we use high‐resolution in situ data from an underwater glider to identify a surface eddy that was masked from remote‐sensing observations. We hypothesize that this masking was driven by thermal stratification driven by surface heat fluxes. The eddy was likely generated north of the Polar Front, before crossing the front and traveling south. We estimate that the observed eddy contained 4 × 1010 m3 of Arctic Water. The observation of this eddy, masked in satellite observations of sea surface temperature, suggests a historical underestimation of the prevalence and importance of eddies in this key mixing region. The water column of the Barents Sea, one of the circumpolar Arctic seas has a seemingly simple structure. In the south, warm Atlantic Water dominates; in the north, cold Arctic Water dominates; while at their boundary, the Arctic Water overlies the Atlantic Water. In the summer, the Arctic Water is largely devoid of the nutrients required to fuel the growth of phytoplankton, which is key to maintaining life in the ocean. In contrast, the Atlantic Water is one of the primary sources of nutrient‐rich water into the Arctic. In this study, we have used an underwater robotic instrument to identify a patch of Arctic Water which has been shed from the Arctic sector of the Barents Sea into the Atlantic sector. This patch of water is seen to have lower phytoplankton concentrations than the surrounding water. Due to atmospheric heating of the surface, this patch would be indistinguishable from the surrounding Atlantic Water and so would be absent for satellite observations of sea surface temperature. We suggest that this temperature masking has meant that we have previously underestimated how much water is moved within these patches in the Arctic seas

    Extraction of arbitrarily shaped objects using stochastic multiple birth-and-death dynamics and active contours

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    We extend the marked point process models that have been used for object extraction from images to arbitrarily shaped objects, without greatly increasing the computational complexity of sampling and estimation. The approach can be viewed as an extension of the active contour methodology to an a priori unknown number of objects. Sampling and estimation are based on a stochastic birth-and-death process defined in a space of multiple, arbitrarily shaped objects, where the objects are defined by the image data and prior information. The performance of the approach is demonstrated via experimental results on synthetic and real data
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