447 research outputs found
A hidden Markov model-based acoustic cicada detector for crowdsourced smartphone biodiversity monitoring
No full textIn recent years, the field of computational sustainability has striven to apply artificial intelligence techniques to solve ecological and environmental problems. In ecology, a key issue for the safeguarding of our planet is the monitoring of biodiversity. Automated acoustic recognition of species aims to provide a cost-effective method for biodiversity monitoring. This is particularly appealing for detecting endangered animals with a distinctive call, such as the New Forest cicada. To this end, we pursue a crowdsourcing approach, whereby the millions of visitors to the New Forest, where this insect was historically found, will help to monitor its presence by means of a smartphone app that can detect its mating call. Existing research in the field of acoustic insect detection has typically focused upon the classification of recordings collected from fixed field microphones. Such approaches segment a lengthy audio recording into individual segments of insect activity, which are independently classified using cepstral coefficients extracted from the recording as features. This paper reports on a contrasting approach, whereby we use crowdsourcing to collect recordings via a smartphone app, and present an immediate feedback to the users as to whether an insect has been found. Our classification approach does not remove silent parts of the recording via segmentation, but instead uses the temporal patterns throughout each recording to classify the insects present. We show that our approach can successfully discriminate between the call of the New Forest cicada and similar insects found in the New Forest, and is robust to common types of environment noise. A large scale trial deployment of our smartphone app collected over 6000 reports of insect activity from over 1000 users. Despite the cicada not having been rediscovered in the New Forest, the effectiveness of this approach was confirmed for both the detection algorithm, which successfully identified the same cicada through the app in countries where the same species is still present, and of the crowdsourcing methodology, which collected a vast number of recordings and involved thousands of contributors.</p
A narrative review on haptic devices: relating the physiology and psychophysical properties of the hand to devices for rehabilitation in central nervous system disorders
No full textPurpose. This paper provides rehabilitation professionals and engineers with a theoretical and pragmatic rationale for the inclusion of haptic feedback in the rehabilitation of central nervous system disorders affecting the hand.Method. A narrative review of haptic devices used in sensorimotor hand rehabilitation was undertaken. Presented papers were selected to outline and clarify the underlying somatosensory mechanisms underpinning these technologies and provide exemplars of the evidence to date.Results. Haptic devices provide kinaesthetic and/or tactile stimulation. Kinaesthetic haptics are beginning to be incorporated in central nervous system rehabilitation, however, there has been limited development of tactile haptics. Clinical research in haptic rehabilitation of the hand is embryonic but initial findings indicate potential clinical benefit. Conclusions. Haptic rehabilitation offers the potential to advance sensorimotor hand rehabilitation but both scientific and pragmatic developments are needed to ensure that its potential is realised.<br/
A giant pancreatic pseudocyst in a patient with HIV infection.
No full textThis article describes the first case of a giant pancreatic pseudocyst in a 48-year-old man with HIV infection under combination antiretroviral therapy. The patient presented with an abdominal mass involving the epigastrium, left hypochondrium, and left flank. An enhanced abdominal computed tomography (CT) scan showed a well-defined cyst of 21 cm in diameter, with a liquid content that dislocated adjacent viscera. Microbiological and cytological tests on fluid were negative, confirming diagnosis of pancreatic pseudocyst. The CT-guided percutaneous drainage was carried out and the patient's clinical condition gradually improved. © The Author(s) 2012
GV and GW invariants via the enhanced movable cone
No full textGiven any smooth germ of a threefold flopping contraction, we first give a combinatorial characterisation of which Gopakumar-Vafa (GV) invariants are non-zero, by prescribing multiplicities to the walls in the movable cone. On the Gromov-Witten (GW) side, this allows us to describe, and even draw, the critical locus of the associated quantum potential. We prove that the critical locus is the infinite hyperplane arrangement of Iyama and the second author, and moreover that the quantum potential can be reconstructed from a finite fundamental domain. We then iterate, obtaining a combinatorial description of the matrix which controls the transformation of the non-zero GV invariants under a flop. There are three main ingredients and applications: (1) a construction of flops from simultaneous resolution via cosets, which describes how the dual graph changes, (2) a closed formula which describes the change in dimension of the contraction algebra under flop, and (3) a direct and explicit isomorphism between quantum cohomologies of different crepant resolutions, giving a Coxeter-style, visual proof of the Crepant Transformation Conjecture for isolated cDV singularities.32 pages. Comments welcome. v2: minor changes. Final version to appear in Modul
Inter-cluster thread-to-core mapping and DVFS on heterogeneous multi-cores
No full textHeterogeneous multi-core platforms that contain different types of cores, organized as clusters, are emerging, e.g. ARM’s big.LITTLE architecture. These platforms often need to deal with multiple applications, having different performance requirements, executing concurrently. This leads to generation of varying and mixed workloads (e.g. compute and memory intensive) due to resource sharing. Run-time management is required for adapting to such performance requirements and workload variabilities and to achieve energy efficiency. Moreover, the management becomes challenging when the applications are multi-threaded and the heterogeneity needs to be exploited. The existing run-time management approaches do not efficiently exploit cores situated in different clusters simultaneously (referred to as inter-cluster exploitation) and DVFS potential of cores, which is the aim of this paper. Such exploitation might help to satisfy the performance requirement while achieving energy savings at the same time. Therefore, in this paper, we propose a run-time management approach that first selects thread-to-core mapping based on the performance requirements and resource availability. Then, it applies online adaptation by adjusting the voltage-frequency (V-f) levels to achieve energy optimization, without trading-off application performance. For thread-to-core mapping, offline profiled results are used, which contain performance and energy characteristics of applications when executed on the heterogeneous platform by using different types of cores in various possible combinations. For an application, thread-to-core mapping process defines the number of used cores and their type, which are situated in different clusters. The online adaptation process classifies the inherent workload characteristics of concurrently executing applications, incurring a lower overhead than existing learning-based approaches as demonstrated in this paper. The classification of workload is performed using the metric Memory Reads Per Instruction (MRPI). The adaptation process pro-actively selects an appropriate V-f pair for a predicted workload. Subsequently, it monitors the workload prediction error and performance loss, quantified by instructions per second (IPS), and adjusts the chosen V-f to compensate. We validate the proposed run-time management approach on a hardware platform, the Odroid-XU3, with various combinations of multi-threaded applications from PARSEC and SPLASH benchmarks. Results show an average improvement in energy efficiency up to 33% compared to existing approaches while meeting the performance requirements
GV/cm scale laser-magnetic resonant acceleration in vacuum
No full textResonant acceleration of electrons by a laser in the background of an extra longitudinal magnetic field is investigated analytically and numerically. The resonant condition is independent of laser intensity, and when satisfied, the energy gain is proportional to a(0)(2) and the square of phase difference. This process is mainly limited by the magnitude and spatial size of the extra magnetic field. Under the laboratory conditions, simulation results show that a monoenergetic and collimated electron bunch can still be obtained in similar to GV/cm scale, which sheds a light on the vacuum table-top laser-driven electron accelerators.National Key Programme for S&TResearch and Development [2016YFA0401100]; China Academy of Engineering Physics Foundation [2014A0102003]SCI(E)ARTICLE3520-5273
On right K-completeness of the fine quasi-uniformity
No full text[EN] We investigate right K-components of the fine quasi-uniformity. It follows from our results the somewhat surprising fact that if (X,T) is a topological space condensable onto a quasi-metric space whose conjugate is Hausdorff, then any right K-Cauchy filter F on the fine quasi-uniformity of (X,T) is trivial (i.e. there is an x €X such that {x} generates F.The second author acknowledges the support of the Conselleria de Educació i Ciencia, Generalitat Valenciana, gran GV-2223/94Perez, M.; Romaguera, S. (1996). On right K-completeness of the fine quasi-uniformity. Questions and Answers in General Topology. 14(2):245-249. https://riunet.upv.es/handle/10251/107319S24524914
Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station
No full textKnowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law. © 2015 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the «http://creativecommons.org/licenses/by/3.0/» Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article&amp;apos;s title, journal citation, and DOI
Photosynthesis down-regulation precedes carbohydrate accumulation under sink limitation in Citrus
No full textPhotosynthesis down-regulation due to an imbalance between sources and sinks in Citrus leaves could be mediated by excessive accumulation of carbohydrates. However, there is limited understanding of the physiological role of soluble and insoluble carbohydrates in photosynthesis regulation and the elements triggering the down-regulation process. In this work, the role of non-structural carbohydrates in the regulation of photosynthesis under a broad spectrum of source-sink relationships has been investigated in the Salustiana sweet orange. Soluble sugar and starch accumulation in leaves, induced by girdling experiments, did not induce down-regulation of the photosynthetic rate in the presence of sinks (fruits). The leaf-to-fruit ratio did not modulate photosynthesis but allocation of photoassimilates to the fruits. The lack of strong sink activity led to a decrease in the photosynthetic rate and starch accumulation in leaves. However, photosynthesis down-regulation due to an excess of total soluble sugars or starch was discarded because photosynthesis and stomatal conductance reduction occurred prior to any significant accumulation of these carbohydrates. Gas exchange and fluorescence parameters suggested biochemical limitations to photosynthesis. In addition, the expression of carbon metabolism-related genes was altered within 24 h when strong sinks were removed. Sucrose synthesis and export genes were inhibited, whereas the expression of ADP-glucose pyrophosphorylase was increased to cope with the excess of assimilates. In conclusion, changes in starch and soluble sugar turnover, but not sugar content per se, could provide the signal for photosynthesis regulation. In these conditions, non-stomatal limitations strongly inhibited the photosynthetic rate prior to any significant increase in carbohydrate levels. © The Author 2011. Published by Oxford University Press. All rights reserved.This work was supported by the Conselleria de Cultura, Educacio i Esport de la Generalitat Valenciana [GV/2007/213 and GV/2009/034].González Nebauer, S.; Renau Morata, B.; Guardiola, JL.; Molina Romero, RV. (2011). Photosynthesis down-regulation precedes carbohydrate accumulation under sink limitation in Citrus. Tree Physiology. 31(2):169-177. doi:10.1093/treephys/tpq103S16917731
TUD-GV Dataset for Floating Litter Detection
No full text<p>This dataset contains the data used for the publication of "Jia T, Vallendar AJ, de Vries R, Kapelan Z and Taormina R (2023) Advancing deep learning-based detection of floating litter using a novel open dataset. <i>Front. Water</i> 5:1298465. doi: 10.3389/frwa.2023.1298465"</p><p>The large-scale "TU Delft - Green Village" (TUD-GV) dataset is for detecting floating litter with computer vision. We created this dataset from experiments conducted during 10 days in February and April 2021 in a small drainage canal at The Green Village — a field lab facility in the TU Delft Campus, the Netherlands. We captured data using two action cameras (GoPro HERO4 and GoPro MAX 360) and a phone (Huawei P30 Pro) mounted on four different locations on a bridge. All devices recorded videos with a resolution of 1080p, a linear field of view, and a FPS (frame per second) of 24 (for the action cameras) or 30 (for the phone).</p><p>This dataset consists of 9,473 RGB images. We manually labeled the images in the TUD-GV dataset into four classes: <i>no litter</i> (0 items), <i>little litter</i> (1-2 items), <i>moderate litter</i> (3-5 items), and <i>lots of litter</i> (6-10 items) according to the number of litter items in images.</p><p>This dataset is stored in the ZIP file contain 77 directories and the TUD-GV.xls file. Each of these directories contain four class label directories, and each label directory contains JPG images. The TUD-GV.xls file contains the detailed information of images in 77 directories, including collecting date, collecting time, device, device location (in a bridge), device degree, device height, weather conditions, litter source, the number of images per class, and the number of images in total.</p><p>If you use this dataset for a publication, please cite the paper. Here is a BibTeX entry:</p><p>@article{jia2023advancing,
title={Advancing Deep Learning-based Detection of Floating Litter using a Novel Open Dataset},
author={Jia, Tianlong and Vallendar, Andre Jehan and de Vries, Rinze and Kapelan, Zoran and Taormina, Riccardo},
journal={Frontiers in Water},
volume={5},
pages={1298465},
publisher={Frontiers},
year={2023}
}</p>
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