Vision-Based Production of Personalized Video

In this paper we present a novel vision-based system for the automated production of personalised video souvenirs for visitors in leisure and cultural heritage venues. Visitors are visually identified and tracked through a camera network. The system produces a personalized DVD souvenir at the end of a visitor’s stay allowing visitors to relive their experiences. We analyze how we identify visitors by fusing facial and body features, how we track visitors, how the tracker recovers from failures due to occlusions, as well as how we annotate and compile the final product. Our experiments demonstrate the feasibility of the proposed approach

Update on insulin treatment of dogs and cats with non-complicated diabetes mellitus

Ο σακχαρώδης διαβήτης είναι μια συχνή ενδοκρινοπάθεια στους σκύλους και τις γάτες και η θεραπευτική του αντιμετώπιση στηρίζεται κυρίως στη χορήγηση ινσουλίνης και τα διαιτητικά μέτρα. Σκοπός της ανασκόπησης αυτής είναι η ενημέρωση του κλινικού Κτηνιάτρου για τα σύγχρονα δεδομένα της θεραπείας με ινσουλίνη σε σκύλους και γάτες με απλό σακχαρώδη διαβήτη. Τα τελευταία χρόνια έχει αλλάξει σημαντικά η θεραπευτική προσέγγιση του νοσήματος, χάρη στη χρησιμοποίηση ινσουλινών με μεγάλη και σταθερή διάρκεια δράσης που δεν προκαλούν έντονη αυξομείωση της συγκέντρωσης της γλυκόζης στο αίμα (ινσουλίνη glargine και detemir) και στην ευρεία εφαρμογή της μέτρησης της συγκέντρωσης της γλυκόζης στο αίμα από τον ιδιοκτήτη του ζώου, στο σπίτι. Η τελευταία γίνεται με τη βοήθεια γλυκοζόμετρου, ύστερα από λήψη τριχοειδικού αίματος από το πτερύγιο του αυτιού ή το πελματικό φύμα. Οι μετρήσεις στο σπίτι πραγματοποιούνται περιοδικά (π.χ. σε εβδομαδιαία βάση), κάθε 1-2 ώρες για το μεσοδιάστημα μεταξύ δυο διαδοχικών χορηγήσεων ινσουλίνης (συνήθως 12 ώρες), αντικαθιστώντας έτσι την καμπύλη γλυκόζης που γινόταν στην κλινική. Επιπλέον, στις γάτες έχει προταθεί να γίνονται 3-5 φορές ημερησίως, σε καθημερινή βάση, προκειμένου να επιτευχθεί με ασφάλεια ο στενός έλεγχος της υπεργλυκαιμίας (μεταξύ 50 και 200 mg dl-1 καθ’ όλη τ η διάρκεια της ημέρας) με συνεχείς τροποποιήσεις της δόσης της ινσουλίνης. Μάλιστα, με το συνδυασμό των διαιτητικών μέτρων, της χορήγησης ινσουλίνης glargine ή detemir και του στενού ελέγχου της υπεργλυκαιμίας έχει αυξηθεί σημαντικά ο αριθμός των γατών εκείνων όπου επιτυγχάνεται προσωρινή ή μόνιμη ύφεση του σακχαρώδη διαβήτη, γεγονός που επιτρέπει τη διακοπή της χορήγησης ινσουλίνης (παροδικός σακχαρώδης διαβήτης). Μια ακόμα ελπιδοφόρα εξέλιξη είναι η ολοένα και συχνότερη χρησιμοποίηση των συσκευών συνεχούς μέτρησης της συγκέντρωσης της γλυκόζης στον υποδόριο ιστό. Χάρη στις συσκευές αυτές, που μπορούν να χρησιμοποιηθούν τόσο στην κλινική όσο και στο σπίτι, υπάρχει η δυνατότητα να μετράται η συγκέντρωση της γλυκόζης κάθε 5 λεπτά για χρονικό διάστημα μέχρι και 72 συνεχόμενων ωρών, γεγονός που επιτρέπει την καλύτερη ρύθμιση της θεραπείας με ινσουλίνη.Diabetes mellitus is a common endocrine disease of dogs and cats. Treatment is mainly based on insulin administration and dietary modifications. The aim of this review is to provide updated information on insulin treatment of dogs and cats with non-complicated diabetes mellitus. During the last years, there has been significant progress in the management of this disease, thanks to the use of long-acting insulin preparations that do not cause pronounced fluctuations of blood glucose concentrations (insulin glargin and detemir) and because of the widespread use of home glucose monitoring by the owners of diabetic pets. Home glucose monitoring is based on capillary blood sampling from the ear pinnae or the foot pad and measurement of blood glucose concentration with a portable blood glucose meter. This can be done periodically (e.g. every week) to replace the traditional in-clinic blood glucose curve; in this case, blood glucose concentration is measured just before the morning insulin administration and then every 1-2 hours until the next dose (usually for 12 hours). Furthermore, especially for the cat, home glucose monitoring can be performed 3-5 times per day, on a daily basis, in order to safely adjust insulin dose and achieve tight control of hyperglycemia (i.e. blood glucose concentration between 50 and 200 mg dl-1 throughout the day). The combination of dietary management, of insulin glargine or detemir administration and of the tight control of hyperglycemia has substantially increased the proportion of cats that enter into temporal or permanent diabetic remission and can be further managed without insulin. Another important achievement is the use of continuous glucose monitoring systems to monitor interstitial fluid glucose concentrations. These devices can be used in the clinic and at home and they can measure glucose concentration every 5 minutes for up to 72 consecutive hours, thus facilitating optimal adjustment of insulin treatment

A new impact model for the flexible rocking oscillator

Motivated by the rocking motion of non-rigid structures during earthquakes, this paper investigates the rocking behaviour of laterally flexible oscillators. Previous studies in this area utilised ad hoc assumptions to consider transitions between different motion phases at impact. Some models explored direct transitions between two rocking phases assuming that elastic translational velocities remain the same, while others assumed the dissipation of all vertical momentum after a rocking phase, leading to a full contact phase upon impact. In this paper, an improved impact model is proposed, where consistent mechanical principles are used to determine the phase transition criteria. The model departs from the principle that the spring and damper elements of the oscillator cannot transfer horizontal impulses over infinitesimally small durations. Alongside other mechanical constraints, this principle yields a series of momentum equations, which are solved to determine the post-impact velocities when transiting from one rocking phase to another. Through these equations, it is shown that a transition to full contact implies a specific locus of the vertical impulse from the support medium. Analytical and numerical investigations are then conducted to comparatively evaluate the new impact model. It is demonstrated that the new impact model yields equivalent results to established rigid rocking impact models for effectively rigid structures and resolves long-standing issues associated with excessive energy dissipation observed in previous models. Time histories of free rocking motion and stability analyses under pulse excitations are used to illustrate and generalise the findings for a range of geometries

A New Model for the Sliding Flexible Rocking Oscillator

A new analytical model called the sliding flexible rocking model (SFRM) is developed to describe the dynamic behaviour of laterally flexible oscillators subjected to earthquakes. The model considers sliding and free flight, that is, complete separation between the structure and the rigid support medium. Phases of motion are defined and the equations of motion for each phase are derived. A hierarchical scheme for transitions between different motion phases is developed. This involves impact‐momentum analyses, which are used to determine the post‐impact states. Simulations show that the new model agrees with authors' earlier flexible rocking model (FRM) when sliding is not present. SFRM also agrees with rigid body rocking models (RSM) allowed to experience sliding and free flight. Comparison between the SFRM and the FRM for slender bodies on low‐grip surfaces show that the sliding in SFRM models greatly affects the overturning stability of the structure. Contrary to what would be expected for rigid rocking bodies, flexible structures can overturn even after experiencing pure sliding. Potential failures due to excessive sliding is also examined. Finally, a new procedure is developed to define the post‐impact phase when the originally chosen impact parameters do not yield an admissible solution. The procedure seeks an admissible solution that minimises the distance of the impulse locus from the impacting corner and respects the hierarchical treatment of phases

An Extended B‐Spline‐Based Material Point Method for Contact Problems

A novel Material Point Method (MPM) is introduced for addressing contact problems. In contrast to the standard multi‐velocity field approach, this method employs a penalty method to evaluate contact forces at the discretised boundaries of their respective physical domains. This enhances simulation fidelity by accurately considering the deformability of the contact surface and preventing fictitious gaps between bodies in contact. Additionally, the method utilises the Extended B‐Splines (EBSs) domain approximation, providing two key advantages. First, EBSs robustly mitigate grid cell‐crossing errors by offering continuous gradients of the basis functions on the interface between adjacent grid cells. Second, numerical integration errors are minimised, even with small physical domains in occupied grid cells. The proposed method's robustness and accuracy are evaluated through benchmarks, including comparisons with analytical solutions, other state‐of‐the‐art MPM‐based contact algorithms, and experimental observations from the literature. Notably, the method demonstrates effective mitigation of stress errors inherent in contact simulations

The dynamic behaviour of flexible oscillators rocking and sliding on concentrated springs

This study presents the Flexible Rocking Model on Concentrated Springs (FRMCS), developed to investigate 2D laterally flexible oscillators rocking and sliding on deformable support media during ground excitations. In this model, concentrated vertical springs and viscous dampers simulate the contact forces from support medium at the corners of the body; the tensionless vertical contact element is linear in compression. Horizontal concentrated springs and linear viscous dampers simulate the frictional behaviour at the corners; the constitutive law for the springs models elastic deformations and sliding (according to Coulomb's friction law). With these elements, FRMCS can model the response of a rocking body which can experience sliding and free‐flight phases of motion. The consideration of the flexibility of the support medium enables the evaluation of the forces exerted by the support medium on the structure during an impact. In this study, the FRMCS response is first compared to a previous model where the support medium deformability and the effects of sliding and free‐flight are ignored. Then, the responses of four configurations, which feature either stiff or soft lateral springs and stiff or soft high‐grip support media, are examined under the influence of pulse excitations. Finally, to understand the potential influence of sliding, a configuration with a low‐grip support medium is explored. The comparative influence of lateral flexibility and support medium deformability and sliding is quantified with stability diagrams and various response spectra, describing structural force and moment demands

Structural identifiability of dynamic systems biology models

22 páginas, 5 figuras, 2 tablas.-- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.A powerful way of gaining insight into biological systems is by creating a nonlinear differential equation model, which usually contains many unknown parameters. Such a model is called structurally identifiable if it is possible to determine the values of its parameters from measurements of the model outputs. Structural identifiability is a prerequisite for parameter estimation, and should be assessed before exploiting a model. However, this analysis is seldom performed due to the high computational cost involved in the necessary symbolic calculations, which quickly becomes prohibitive as the problem size increases. In this paper we show how to analyse the structural identifiability of a very general class of nonlinear models by extending methods originally developed for studying observability. We present results about models whose identifiability had not been previously determined, report unidentifiabilities that had not been found before, and show how to modify those unidentifiable models to make them identifiable. This method helps prevent problems caused by lack of identifiability analysis, which can compromise the success of tasks such as experiment design, parameter estimation, and model-based optimization. The procedure is called STRIKE-GOLDD (STRuctural Identifiability taKen as Extended-Generalized Observability with Lie Derivatives and Decomposition), and it is implemented in a MATLAB toolbox which is available as open source software. The broad applicability of this approach facilitates the analysis of the increasingly complex models used in systems biology and other areasAFV acknowledges funding from the Galician government (Xunta de Galiza, Consellería de Cultura, Educación e Ordenación Universitaria http://www.edu.xunta.es/portal/taxonomy/term/206) through the I2C postdoctoral program, fellowship ED481B2014/133-0. AB and AFV were partially supported by grant DPI2013-47100-C2-2-P from the Spanish Ministry of Economy and Competitiveness (MINECO). AFV acknowledges additional funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 686282 (CanPathPro). AP was partially supported through EPSRC projects EP/M002454/1 and EP/J012041/1.Peer reviewe

Monopile foundation stiffness estimation of an instrumented offshore wind turbine through model updating

Rapid development of offshore wind foundation models has resulted in a large number of built structures with generally underestimated foundation stiffness properties and a need to update and validate both the individual structural models and the underlying foundation design frameworks. This paper outlines a structural health monitoring approach, based on the combination of output only structural health monitoring methods and model updating, to estimate foundation stiffness parameters using field monitored data. Field monitoring data from an offshore wind turbine under idling conditions, over a large monitoring period, are presented and operational modal analysis is applied to estimate the modal parameters. Those are compared to modal properties predicted by finite element models, employing either old (API/DNVGL) or new (PISA) foundation design properties, which are calibrated using geotechnical site investigation data. A new approach to interpret seabed level statically equivalent foundation stiffness, in terms of effective lateral and rotational stiffness against load eccentricity, is presented. Seabed level statically equivalent foundation properties are updated by comparison against the observed modal behaviour and the optimised foundation parameters are presented, demonstrating a close match to the predictions of the PISA method