735 research outputs found

    A Deep Siamese Network for Scene Detection in Broadcast Videos

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    We present a model that automatically divides broadcast videos into coherent scenes by learning a distance measure between shots. Experiments are performed to demonstrate the effectiveness of our approach by comparing our algorithm against recent proposals for automatic scene segmentation. We also propose an improved performance measure that aims to reduce the gap between numerical evaluation and expected results, and propose and release a new benchmark dataset.Comment: ACM Multimedia 201

    Loads on a gymnastics safety support system during maximal use

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    Support systems can be used to prevent or reduce the impact during landings in various gymnastics disciplines. A support system typically consists of two ropes, three pulleys attached to steelwork in the roof space of the gymnasium, and a belt around the gymnast's waist. The aim of the study was to determine the forces at the pulleys and the tension in the ropes during maximal loading for a dynamic gymnastics skill. Additionally the relationships between the drop height and the peak force and between the gymnast mass and the peak force, together with the effect of the coach's actions, were investigated. A gymnastics support system was instrumented with strain-gauge-based load cells. A coach attempted to arrest the fall of a gymnast equivalent mass (range, 10—35 kg) over a range of drop heights (0.25—1.5 m). To establish the coach's contribution, trials were repeated with the coach replaced by an equivalent mass and with the rope tied off to the floor. Peak forces of 1.3 kN were recorded for a simulated maximum loading gymnastics scenario (drop height, 1.25 m; gymnast mass, 35 kg). The coach's actions reduced the peak forces by 35 per cent and 48 per cent in comparison with an equivalent deadweight and with the rope tied off respectively

    Spectroscopic study of the interaction of U(VI) with transferrin and albumin for speciation of U(VI) under blood serum conditions

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    International audienceThe quantitative description of the interactions of uranium with blood serum components is of high relevance for a rational design of molecules suitable for in vivo chelation of uranium. We have determined the stability constants for the complexation of U(VI) with human serum transferrin and albumin by time-resolved laser-induced fluorescence spectroscopy and difference ultraviolet spectroscopy. Both proteins interact strongly with U(VI), forming ternary complexes with carbonate acting as a synergistic anion. Together with literature data describing the interaction of U(VI) with low molecular weight inorganic and organic serum components, the speciation of U(VI) in blood serum was calculated. In agreement with published experimental data, the model calculation shows that complexation with proteins and carbonate ion governs U(VI) speciation: 35% of U(VI) is bound to proteins and 65% to carbonate. Among the protein pool, albumin is the main protein interacting with U(VI). In addition, the results show that Ca(II) must be considered in the model as a competitive metal ion with respect to U(VI) for binding to albumin surface sites. Based on these findings several promising molecules for in vivo chelation of U-230 could be identified. (C) 2009 Elsevier Inc. All rights reserved

    AC-SUM-GAN: Connecting Actor-Critic and Generative Adversarial Networks for Unsupervised Video Summarization

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    This paper presents a new method for unsupervised video summarization. The proposed architecture embeds an Actor-Critic model into a Generative Adversarial Network and formulates the selection of important video fragments (that will be used to form the summary) as a sequence generation task. The Actor and the Critic take part in a game that incrementally leads to the selection of the video key-fragments, and their choices at each step of the game result in a set of rewards from the Discriminator. The designed training workflow allows the Actor and Critic to discover a space of actions and automatically learn a policy for key-fragment selection. Moreover, the introduced criterion for choosing the best model after the training ends, enables the automatic selection of proper values for parameters of the training process that are not learned from the data (such as the regularization factor σ). Experimental evaluation on two benchmark datasets (SumMe and TVSum) demonstrates that the proposed AC-SUM-GAN model performs consistently well and gives SoA results in comparison to unsupervised methods, that are also competitive with respect to supervised methods

    In memoriam: Serge Moscovici (1925-2014)

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    International audiencePreface by the EASP Executive Committee and the Chief Editors of EJS

    Investigation of para-sulfonatocalix[n]arenes [n = 6, 8] as potential chelates for 230U

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    International audienceLiterature reports of the efficacy of para-sulfonatocalix[6]- and calix[8]-arenes as U(VI) complexants indicated that they might be useful for in vivo chelation of the novel therapeutic alhpa-emitter 230U. We have studied the complexation of U(VI) with para-sulfonatocalix[6]arene and para-sulfonatocalix[8]arene by time resolved laser induced fluorescence spectroscopy and using competition methods with Chelex resin and 4-(2-pyridylazo)resorcinol in simplified and in biological media. New thermodynamic parameters describing the stability of U(VI)-para-sulfonatocalix[n]arene [n = 6, 8] complexes were obtained. Although the interactions are strong, the complexes do not exhibit sufficient stability to compete with carbonate ions and serum proteins for complexation of U(VI) under physiological conditions

    Foramen magnum, occipital condyles and hypoglossal canals morphometry: anatomical study with clinical implications

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    Background: Current study examines morphometric alterations of the foramen magnum (FM), occipital condyles (OCs) and hypoglossal canals (HCs) and highlights all the morphometric parameters of the FM area that present side asymmetry, gender dimorphism and are affected by the ageing. Materials and methods: One hundred and forty-one (73 male and 68 female) Greek adult dry skulls were examined. Results: Short and long OCs were detected in 27.7% and 26.2%. A combination of short OCs and long HCs was presented in 27.5%. A complete septum was found in 23.6% of the HCs and osseous spurs in 12.9%. Side asymmetry was detected regarding the HCs length (p = 0.046), the maximum extracranial (p = 0.001) and minimum intracranial (p = 0.001) diameters. Mean FM anteroposterior and transverse diameters, FM perimeter and FM surface area were significantly larger in male than in female skulls (p = 0.001 for each parameter). Similarly, the OCs length (right, p = 0.004 and left, p = 0.024) and width (right, p = 0.008 and left, p = 0.006) the left distance HC-OC posterior border (p = 0.048), the anterior (p = 0.011) and posterior (p = 0.001) intercondylar distances and the HCs right length (p = 0.046) were significantly greater in males. A significant decrease was observed with ageing in FM anteroposterior diameter (p = 0.038), FM surface area (p = 0.05), anterior intercondylar distance (p = 0.014) and HC-OC posterior border (p = 0.013). Conclusions: The study confirmed that only specific HC dimensions showed side asymmetry (HCs maximum extracranial and minimum intracranial diameters and HCs length), gender dimorphism (HCs right length and left distance HC-OC posterior border) and age influence (HC-OC posterior border and HC left extracranial minimum diameter) among young, adults and elderly individuals. FM and OCs dimensions presented gender dimorphism and the age influenced only FM anteroposterior diameter and surface area and the anterior intercondylar distance. The safe zone of OCs drilling in Greeks, calculated by the distance HC-OC posterior border represents the maximum HC depth and is among the lowest values reported in the literature. The significant decrease of this distance with ageing confirms the existence of a drilling safe zone for young, adults and elder individuals. Regarding OCs length, the same probability exists dealing with a short or a long OC during condylectomy. Before planning a transcondylar approach, the coexistence of short OCs and long HCs should be taken into account. These outcomes will be useful for a safe surgery in the craniocervical region in Greeks

    VideoAnalysis4ALL: An On-line Tool for the Automatic Fragmentation and Concept-based Annotation, and the Interactive Exploration of Videos.

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    This paper presents the VideoAnalysis4ALL tool that supports the automatic fragmentation and concept-based annotation of videos, and the exploration of the annotated video fragments through an interactive user interface. The developed web application decomposes the video into two different granularities, namely shots and scenes, and annotates each fragment by evaluating the existence of a number (several hundreds) of high-level visual concepts in the keyframes extracted from these fragments. Through the analysis the tool enables the identification and labeling of semantically coherent video fragments, while its user interfaces allow the discovery of these fragments with the help of human-interpretable concepts. The integrated state-of-the-art video analysis technologies perform very well and, by exploiting the processing capabilities of multi-thread / multi-core architectures, reduce the time required for analysis to approximately one third of the video’s duration, thus making the analysis three times faster than real-time processing
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