42 research outputs found

    Cross-View Action Recognition from Temporal Self-Similarities

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    This paper concerns recognition of human actions under view changes. We explore self-similarities of action sequences over time and observe the striking stability of such measures across views. Building upon this key observation we develop an action descriptor that captures the structure of temporal similarities and dissimilarities within an action sequence. Despite this descriptor not being strictly view-invariant, we provide intuition and experimental validation demonstrating the high stability of self-similarities under view changes. Self-similarity descriptors are also shown stable under action variations within a class as well as discriminative for action recognition. Interestingly, self-similarities computed from different image features possess similar properties and can be used in a complementary fashion. Our method is simple and requires neither structure recovery nor multi-view correspondence estimation. Instead, it relies on weak geometric cues captured by self-similarities and combines them with machine learning for efficient cross-view action recognition. The method is validated on three public datasets, it has similar or superior performance compared to related methods and it performs well even in extreme conditions such as when recognizing actions from top views while using side views for training only

    Biometrics in forensic science: challenges, lessons and new technologies

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    Biometrics has historically found its natural mate in Forensics. The first applications found in the literature and over cited so many times, are related to biometric measurements for the identification of multiple offenders from some of their biometric and anthropometric characteristics (tenprint cards) and individualization of offender from traces found on crime-scenes (e.g. fingermarks, earmarks, bitemarks, DNA). From sir Francis Galton, to the introduction of AFIS systems in the scientific laboratories of police departments, Biometrics and Forensics have been "dating" with alternate results and outcomes. As a matter of facts there are many technologies developed under the "Biometrics umbrella" which may be optimised to better impact several Forensic scenarios and criminal investigations. At the same time, there is an almost endless list of open problems and processes in Forensics which may benefit from the introduction of tailored Biometric technologies. Joining the two disciplines, on a proper scientific ground, may only result in the success for both fields, as well as a tangible benefit for the society. A number of Forensic processes may involve Biometric-related technologies, among them: Evidence evaluation, Forensic investigation, Forensic Intelligence, Surveillance, Forensic ID management and Verification.\ud The COST Action IC1106 funded by the European Commission, is trying to better understand how Biometric and Forensics synergies can be exploited within a pan-European scientific alliance which extends its scope to partners from USA, China and Australia.\ud Several results have been already accomplished pursuing research in this direction. Notably the studies in 2D and 3D face recognition have been gradually applied to the forensic investigation process. In this paper a few solutions will be presented to match 3D face shapes along with some experimental results

    Composition and antimicrobial activity of the essential oil of Thymus fontanesii

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    The yield of oil isolated by hydrodistillation from aerial parts of Thymus fontanesii Boiss. et Reut. (Lamiaceae) growing wild in Djelfa (Algeria) was 0.9%. Analysis of the oil by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) revealed the identification of 47 components accounting for 98.5% of the total oil. The oil was found to be rich in monoterpenes (91.5%) with major constituents being thymol (29.3%), γ-terpinene (21.7%), p-cymene (15.9%), and thymol methyl ether (11.4%), while a smaller amount of linalool (4.8%) and β-caryophyllene (2.9%) were detected. According to the antimicrobial study using the disk diffusion method and the agar dilution assay-minimal inhibitory concentration (MIC), the oil showed strong in vitro growth inhibition activity against Gram-negative bacteria and antifungal activity. The oil exhibited the maximum antifungal activity against Mucor ramaniamus (MIC = 0.2 μL/mL). © 2006 Informa Healthcar

    Studies on the essential oil composition and antimicrobial activity of Thymus algeriensis Boiss

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    Many species of Thymus have been widely used in Algerian folk medicine as astringent, expectorant and cicatrising agents. This study was designed to investigate for the first time the essential oil of the aerial parts of wild growing Thymus algeriensis endemic in North Africa. The volatile oil obtained by hydrodistillation was characterized by the physico-chemical properties, GC and GC/MS techniques. The yield of the oil was 1.13% (w/w), based on dry weight. Fifty-five components, representing 94.3% of the total oil, were identified. The oil was distinguished by its high content of oxygenated monoterpenes (79.5%) and was found to possess the following major components: linalool (47.3%), thymol (29.2%) and p-cymene (6.8%). Furthermore, the oil was tested for antimicrobial activity against four bacteria, two fungi and two yeasts. This oil exhibited a significant in vitro antimicrobial activity against Bacillus subtilis (MIC = 0.5 μL/mL), as well as against all yeast and all filamentous fungi tested (MIC = 0.5 and 1.0 μL/mL). © 2006 Elsevier Ltd. All rights reserve

    Chemical composition of the essential oil of Salvia officinalis from Algeria

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    Sage (Salvia spp.), belonging to the Lamiaceae family, is an aromatic plant and includes about 900 species that grow in several regions all over the world [1]. This genus showed a very high variability of both morphological and cariological characters [2]. Since ancient times, this genus has been used in folk medicine and as a flavoring agen
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