701 research outputs found

    Characteristic and necessary minutiae in fingerprints

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    Fingerprints feature a ridge pattern with moderately varying ridge frequency (RF), following an orientation field (OF), which usually features some singularities. Additionally at some points, called minutiae, ridge lines end or fork and this point pattern is usually used for fingerprint identification and authentication. Whenever the OF features divergent ridge lines (e.g., near singularities), a nearly constant RF necessitates the generation of more ridge lines, originating at minutiae. We call these the necessary minutiae. It turns out that fingerprints feature additional minutiae which occur at rather arbitrary locations. We call these the random minutiae or, since they may convey fingerprint individuality beyond the OF, the characteristic minutiae. In consequence, the minutiae point pattern is assumed to be a realization of the superposition of two stochastic point processes: a Strauss point process (whose activity function is given by the divergence field) with an additional hard core, and a homogeneous Poisson point process, modelling the necessary and the characteristic minutiae, respectively. We perform Bayesian inference using an Markov-Chain-Monte-Carlo (MCMC)-based minutiae separating algorithm (MiSeal). In simulations, it provides good mixing and good estimation of underlying parameters. In application to fingerprints, we can separate the two minutiae patterns and verify by example of two different prints with similar OF that characteristic minutiae convey fingerprint individuality

    A Consistent Metric for Performance Evaluation of Multi-Object Filters

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    The concept of a miss-distance, or error, between a reference quantity and its estimated/controlled value, plays a fundamental role in any filtering/control problem. Yet there is no satisfactory notion of a miss-distance in the well-established field of multi-object filtering. In this paper, we outline the inconsistencies of existing metrics in the context of multi-object miss-distances for performance evaluation. We then propose a new mathematically and intuitively consistent metric that addresses the drawbacks of current multi-object performance evaluation metrics

    Die Bedeutung von Open Innovation in Innovationsnetzwerken : Einblicke in die Automobilindustrie

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    Die Entwicklung von Innovation wird vermehrt als ein dynamisches Zusammenspiel unterschiedlichster Akteure angesehen. Steigende Wettbewerbsanforderungen sowie die Gefahr von hohen Flopraten haben in vielen Unternehmen dazu geführt, dass die Anforderungen und Bedürfnisse aktueller und potentieller Kunden detailliert in Form der Kundenintegration analysiert werden. Durch die Einbindung von Kunden in die Innovationsentwicklung wird es Unternehmen möglich, genaue Erkenntnisse über den Kunden zu gewinnen bzw. von dessen Know-how zu rofitieren. Die Tätigkeit von Unternehmen innerhalb von Netzwerken, insbesondere Innovationsnetzwerken, wird in Zukunft einen größeren Einfluss auf die Wettbewerbsfähigkeit von Unternehmen nehmen. Aufgrund dieser Bedeutung der beiden Themenfelder Kundenintegration und Innovationsnetzwerke für die Innovationsentwicklung, stellt sich die Frage, inwieweit eine Integration von Kunden in Innovationsnetzwerke im Verlauf des 21. Jahrhunderts stattfinden wird. Im Rahmen der vorliegenden Arbeit wird daher anhand einer Literaturanalyse der Forschungsstand der beiden Themenfelder in der wissenschaftlichen Literatur dargestellt. Dies geschieht separat, da bisher diese beiden Forschungsbereiche noch nicht gemeinsam untersucht wurden. Es zeigt sich, dass für die erfolgreiche Tätigkeit innerhalb eines Innovationsnetzwerkes, ein Unternehmen eine Unternehmenskultur der Open Innovation entwickelt. In Bezug auf die Kundenintegration in die Innovationsentwicklung kann sowohl der Zeitpunkt der Einbindung des Kunden, die Intensität dieser Einbindung sowie gewisse Kundenmerkmale als besonders erfolgsrelevant identifiziert werden. Anhand einer qualitativen Studie wird die Bedeutung der identifizierten erfolgsrelevanten Dimensionen der Kundenintegration innerhalb von Innovationsnetzwerken aus Unternehmenssicht betrachtet. Hierzu wurden Experten mit Hilfe von direkten Interviews befragt, um in erster Linie qualitative Informationen zum Untersuchungsgegenstand zu erhalten. Ein Vergleich zwischen dem Status Quo der Kundenintegration und der künftigen Kundenintegration innerhalb von Innovationsnetzwerken deckt dabei Unterschiede und Gemeinsamkeiten auf. Aufgrund dieser Erkenntnisse werden abschließend Implikationen für die Unternehmenspraxis abgeleitet

    Comparative In Vitro Toxicity Evaluation of Heavy Metals (Lead, Cadmium, Arsenic, and Methylmercury) on HT-22 Hippocampal Cell Line

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    Heavy metals are considered some of the most toxic environmental pollutants. Exposure to heavy metals including lead (Pb), cadmium (Cd), arsenic (As), and methyl mercury (MeHg) has long been known to cause damage to human health. Many recent studies have supported the hippocampus as the major target for these four metals for inflicting cognitive dysfunction. In the present study, we proposed hippocampal relevant in vitro toxicity of Pb, Cd, As, and MeHg in HT-22 cell line. This study reports, initially, cytotoxic effects in acute, subchronic, chronic exposures. We further investigated the mechanistic potency of DNA damage and apoptosis damage with the observed cytotoxicity. The genotoxicity and apoptosis were measured by using the comet assay, annexin-V FTIC / propidium iodide (PI) assay, respectively. The results of cytotoxicity assay clearly demonstrated significant concentration and time-dependent effects on HT-22 cell line. The genotoxic and apoptosis effects also concentration-dependent fashion with respect to their potency in the range of IC10-IC30, maximal level of damage observed in MeHg. In conclusion, the obtained result suggests concentration and potency-dependent response; the maximal level of toxicity was observed in MeHg. These novel findings support that Pb, Cd, As, and MeHg induce cytotoxic, genotoxic, and apoptotic effects on HT-22 cells in potency-dependent manner; MeHg> As> Cd> Pb. Therefore, the toxicity of Pb, Cd, As, and MeHg could be useful for knowing the common underlying molecular mechanism, and also for estimating the mixture impacts on HT-22 cell line

    Localization Recall Precision (LRP): A New Performance Metric for Object Detection

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    Average precision (AP), the area under the recall-precision (RP) curve, is the standard performance measure for object detection. Despite its wide acceptance, it has a number of shortcomings, the most important of which are (i) the inability to distinguish very different RP curves, and (ii) the lack of directly measuring bounding box localization accuracy. In this paper, we propose 'Localization Recall Precision (LRP) Error', a new metric which we specifically designed for object detection. LRP Error is composed of three components related to localization, false negative (FN) rate and false positive (FP) rate. Based on LRP, we introduce the 'Optimal LRP', the minimum achievable LRP error representing the best achievable configuration of the detector in terms of recall-precision and the tightness of the boxes. In contrast to AP, which considers precisions over the entire recall domain, Optimal LRP determines the 'best' confidence score threshold for a class, which balances the trade-off between localization and recall-precision. In our experiments, we show that, for state-of-the-art object (SOTA) detectors, Optimal LRP provides richer and more discriminative information than AP. We also demonstrate that the best confidence score thresholds vary significantly among classes and detectors. Moreover, we present LRP results of a simple online video object detector which uses a SOTA still image object detector and show that the class-specific optimized thresholds increase the accuracy against the common approach of using a general threshold for all classes. At https://github.com/cancam/LRP we provide the source code that can compute LRP for the PASCAL VOC and MSCOCO datasets. Our source code can easily be adapted to other datasets as well.Comment: to appear in ECCV 201

    A traceless photocleavable linker for the automated glycan assembly of carbohydrates with free reducing ends

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    We report a traceless photocleavable linker for the automated glycan assembly of carbohydrates with free reducing ends. The reductive-labile functionality in the linker tolerates all commonly used reagents and protocols for automated glycan assembly, as demonstrated with the successful preparation of nine plant cell wall-related oligosaccharides, and is cleaved by hydrogenolysis

    First neutron spectroscopy measurements in the ASDEX Upgrade tokamak

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    Abstract: A compact neutron spectrometer based on the liquid scintil-lator BC501A has been installed on the ASDEX Upgrade tokamak. The aim is to measure neutron energy distribution functions as footprints of fast ions distribution functions, generated mainly via Neutral Beam Injection (NBI) in present day tokamaks. A flexible and fast software has been developed to perform digital pulse shape separation and to evaluate pulse height spectra. First measurements of count rates and pulse height spectra show a good sig-nal to noise ratio for integration times comparable to the NBI slowing down time and to the energy confinement time. Due to the perpendicular line of sight, D-d fusion with perpendicular NBI is detected more efficiently and the line broadening of the 2.45 MeV neutrons is higher. Ion Cyclotron Reso-nance Heating (ICRH) combined to NBI exhibits a synergy effect, with count rates higher than the sum of the counts due to NBI and ICRH separately. Although the collimator is designed to screen gammas as much as possible, some qualitative gamma analysis is also possible, providing information in case of runaway electrons during disruptions. The experimental campaign for the characterisation of the system (detector + acquisition system) is complete and the determination of the response function is in progress.
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