241 research outputs found

    Solid and Effective Upper Limb Segmentation in Egocentric Vision

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    Upper limb segmentation in egocentric vision is a challenging and nearly unexplored task that extends the well-known hand localization problem and can be crucial for a realistic representation of users' limbs in immersive and interactive environments, such as VR/MR applications designed for web browsers that are a general-purpose solution suitable for any device. Existing hand and arm segmentation approaches require a large amount of well-annotated data. Then different annotation techniques were designed, and several datasets were created. Such datasets are often limited to synthetic and semi-synthetic data that do not include the whole limb and differ significantly from real data, leading to poor performance in many realistic cases. To overcome the limitations of previous methods and the challenges inherent in both egocentric vision and segmentation, we trained several segmentation networks based on the state-of-the-art DeepLabv3+ model, collecting a large-scale comprehensive dataset. It consists of 46 thousand real-life and well-labeled RGB images with a great variety of skin colors, clothes, occlusions, and lighting conditions. In particular, we carefully selected the best data from existing datasets and added our EgoCam dataset, which includes new images with accurate labels. Finally, we extensively evaluated the trained networks in unconstrained real-world environments to find the best model configuration for this task, achieving promising and remarkable results in diverse scenarios. The code, the collected egocentric upper limb segmentation dataset, and a video demo of our work will be available on the project page1

    Human segmentation in surveillance video with deep learning

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    Advanced intelligent surveillance systems are able to automatically analyze video of surveillance data without human intervention. These systems allow high accuracy of human activity recognition and then a high-level activity evaluation. To provide such features, an intelligent surveillance system requires a background subtraction scheme for human segmentation that captures a sequence of images containing moving humans from the reference background image. This paper proposes an alternative approach for human segmentation in videos through the use of a deep convolutional neural network. Two specific datasets were created to train our network, using the shapes of 35 different moving actors arranged on background images related to the area where the camera is located, allowing the network to take advantage of the entire site chosen for video surveillance. To assess the proposed approach, we compare our results with an Adobe Photoshop tool called Select Subject, the conditional generative adversarial network Pix2Pix, and the fully-convolutional model for real-time instance segmentation Yolact. The results show that the main benefit of our method is the possibility to automatically recognize and segment people in videos without constraints on camera and people movements in the scene (Video, code and datasets are available at http://graphics.unibas.it/www/HumanSegmentation/index.md.html)

    A Preliminary Investigation into a Deep Learning Implementation for Hand Tracking on Mobile Devices

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    Hand tracking is an essential component of computer graphics and human-computer interaction applications. The use of RGB camera without specific hardware and sensors (e.g., depth cameras) allows developing solutions for a plethora of devices and platforms. Although various methods were proposed, hand tracking from a single RGB camera is still a challenging research area due to occlusions, complex backgrounds, and various hand poses and gestures. We present a mobile application for 2D hand tracking from RGB images captured by the smartphone camera. The images are processed by a deep neural network, modified specifically to tackle this task and run on mobile devices, looking for a compromise between performance and computational time. Network output is used to show a 2D skeleton on the user's hand. We tested our system on several scenarios, showing an interactive hand tracking level and achieving promising results in the case of variable brightness and backgrounds and small occlusions

    Freehand-Steering Locomotion Techniques for Immersive Virtual Environments: A Comparative Evaluation

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    Virtual reality has achieved significant popularity in recent years, and allowing users to move freely within an immersive virtual world has become an important factor critical to realize. The user’s interactions are generally designed to increase the perceived realism, but the locomotion techniques and how these affect the user’s task performance still represent an open issue, much discussed in the literature. In this article, we evaluate the efficiency and effectiveness of, and user preferences relating to, freehand locomotion techniques designed for an immersive virtual environment performed through hand gestures tracked by a sensor placed in the egocentric position and experienced through a head-mounted display. Three freehand locomotion techniques have been implemented and compared with each other, and with a baseline technique based on a controller, through qualitative and quantitative measures. An extensive user study conducted with 60 subjects shows that the proposed methods have a performance comparable to the use of the controller, further revealing the users’ preference for decoupling the locomotion in sub-tasks, even if this means renouncing precision and adapting the interaction to the possibilities of the tracker sensor

    Understanding how the strategic similarities between energy companies influence the post-mergers and acquisitions performances

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    The energy sector has experienced rapid evolution in recent years, following the liberalization of the electricity and natural gas markets, driven by the European Union. These developments have led to a certain level of dynamism in Italy, particularly as concerns mergers and acquisitions (M&As) within the sector. This article examines the influence of strategic similarities between the target and bidder companies on their post-M&A performances. The model used involves a hierarchical regression relating the indexes of similarity between the merging companies, regarding their economic-financial management. The results reveal the influence of the strategic similarities and differences on the post-M&A performances of the companies, showing how the positive or negative effect depends on certain characteristics, such as their structure of share capital, business segments and size. The study evidences the strategic variables that should be considered in choosing the optimal target companies

    1-Butanol dehydration and oxidation over vanadium phosphate catalysts

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    The transformation of 1-butanol into either butenes or maleic anhydride was carried out both with and without oxygen, using V/P/O catalysts. With vanadyl pyrophosphate prepared by coprecipitation, at temperature lower than 240 ◦C and without oxygen, selectivity to butenes was higher than 90%, but a slow deactivation took place. At temperature higher than 300 ◦C and in the presence of air, maleic and phthalic anhydrides were the prevailing products, with selectivity of 60% and 14%, respectively. Catalytic performance was affected by crystallinity and acidity. αI-VOPO4 showed a poor performance in the absence of air, with a quick deactivation due to coke accumulation; but it displayed an excellent selectivity to butenes (close to 98%) at temperatures lower than 320 ◦C in the presence of air, with stable performance. At temperature higher than 360 ◦C, α I-VOPO4 was reduced to vanadyl pyrophosphate and catalyzed the direct oxidation of 1-butanol into maleic anhydride, but with 35% selectivit

    Genome Sequencing and Comparative Analysis of Three Hanseniaspora uvarum Indigenous Wine Strains Reveal Remarkable Biotechnological Potential

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    A current trend in winemaking has highlighted the beneficial contribution of non-Saccharomyces yeasts to wine quality. Hanseniaspora uvarum is one of the more represented non-Saccharomyces species onto grape berries and plays a critical role in influencing the wine sensory profile, in terms of complexity and organoleptic richness. In this work, we analyzed a group of H. uvarum indigenous wine strains as for genetic as for technological traits, such as resistance to SO2 and beta-glucosidase activity. Three strains were selected for genome sequencing, assembly and comparative genomic analyses at species and genus level. Hanseniaspora genomes appeared compact and contained a moderate number of genes, while rarefaction analyses suggested an open accessory genome, reflecting a rather incomplete representation of the Hanseniaspora gene pool in the currently available genomes. The analyses of patterns of functional annotation in the three indigenous H. uvarum strains showed distinct enrichment for several PFAM protein domains. In particular, for certain traits, such as flocculation related protein domains, the genetic prediction correlated well with relative flocculation phenotypes at lab-scale. This feature, together with the enrichment for oligo-peptide transport and lipid and amino acid metabolism domains, reveals a promising potential of these indigenous strains to be applied in fermentation processes and modulation of wine flavor and aroma. This study also contributes to increasing the catalog of publicly available genomes from H. uvarum strains isolated from natural grape samples and provides a good roadmap for unraveling the biodiversity and the biotechnological potential of these non-Saccharomyces yeasts

    Toxicity of antioxidant supplements in patients with male factor infertility: A systematic review and meta-analysis of randomized controlled trials

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    Treating oxidative stress through antioxidant therapy has been considered an appealing strategy in the management of male infertility. However, evidence regarding the toxicity of an-tioxidant therapy is controversial. We summarized the available clinical evidence on the toxicity associated with the use of antioxidants in infertile males. A systematic review was performed in March 2021. We included randomized controlled trials evaluating the incidence of adverse events in male patients with infertility receiving antioxidant therapy. Thirteen studies involving 1999 male patients were identified. Antioxidant supplementation in patients with male factor infertility was associated with a statistically significantly increased risk of nausea (Odds Ratio: 2.16, 95% Confidence Interval: 1.05–4.43, p = 0.036), headache (Odds Ratio: 3.05, 95% Confidence Interval: 1.59– 5.85 p = 0.001), and dyspepsia (Odds Ratio: 4.12, 95% Confidence Interval: 1.43–11.85, p = 0.009) compared to a placebo. Treatment discontinuation due to adverse events was not significantly higher in patients taking antioxidants compared to a placebo (Odds Ratio: 2.29, 95% Confidence Interval: 0.76–6.88, p = 0.139). When antioxidant supplementation is considered, a more accurate risk/benefit analysis is warranted

    Collagenase clostridium histolyticum for the treatment of Peyronie's disease: a prospective Italian multicentric study

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    Peyronie's disease (PD) is a common condition which results in penile curvature making sexual intercourse difficult or impossible. Collagenase clostridium histolyticum (CCH) is the first licensed drug for the treatment of PD and is indicated in patients with palpable plaque and curvature deformity of at least 30° of curvature. However, only few monocentric studies are available in the current literature and this is the first national multicentric study focusing on this new treatment. In five Italian centres, 135 patients have completed the treatment with three injections of CCH using Ralph's shortened modified protocol. The protocol consisted of three intralesional injections of CCH (0.9 mg) given at 4-weekly intervals in addiction to a combination of home modelling, stretching and a vacuum device on a daily basis. An improvement in the angle of curvature was recorded in 128/135 patients (94.8%) by a mean (range) of 19.1 (0–40)° or 42.9 (0–67)% from baseline (p < 0.001). There was also a statistically significant improvement in all IIEF and PDQ questionnaires subdomains (p < 0.001 in all subdomains). This prospective multicentric study confirms that the three-injection protocol is effective enough to achieve a good result and to minimize the cost of the treatment
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