198 research outputs found
Robust Online Monitoring of Signal Temporal Logic
Signal Temporal Logic (STL) is a formalism used to rigorously specify
requirements of cyberphysical systems (CPS), i.e., systems mixing digital or
discrete components in interaction with a continuous environment or analog com-
ponents. STL is naturally equipped with a quantitative semantics which can be
used for various purposes: from assessing the robustness of a specification to
guiding searches over the input and parameter space with the goal of falsifying
the given property over system behaviors. Algorithms have been proposed and
implemented for offline computation of such quantitative semantics, but only
few methods exist for an online setting, where one would want to monitor the
satisfaction of a formula during simulation. In this paper, we formalize a
semantics for robust online monitoring of partial traces, i.e., traces for
which there might not be enough data to decide the Boolean satisfaction (and to
compute its quantitative counterpart). We propose an efficient algorithm to
compute it and demonstrate its usage on two large scale real-world case studies
coming from the automotive domain and from CPS education in a Massively Open
Online Course (MOOC) setting. We show that savings in computationally expensive
simulations far outweigh any overheads incurred by an online approach
Subjective Postural Vertical and Adolescent Idiopathic Scoliosis (AIS)
ObjectiveThe origin of the AIS is unknown. Several studies in AIS have shown disturbances of orthostatic postural control and somatosensory modality. The orthostatic postural control is the ability to organize the upright position on the earth-vertical, by multisensory central integration, especially somatosensory information. Our hypothesis is that the somatosensory disturbances in the AIS involve change in the organization of orthostatic postural control, around an erroneous central representation of verticality. Our objective is to test, in the AIS, the existence of a disturbance of the somatosensory modality in orthostatic postural control by measuring the Subjective Postural Vertical (SPV).MethodsUncontrolled preliminary study on 8 adolescents with SIA (7 girls, 13.8±0.83 years, 38.8±10.4°angle). Test=SPV measurement, vision obscured, head-trunk-members strapped, sitting on a seat, fixed to a German vertical wheel athletic gymnastics (external diameter: 1.90 m), with electronic inclinometer that measures the rotational tilt of the seat, with reference to the gravitational vertical. From 45° inclination, the subject is tilted (1°/sec) and evaluates the alignment with the vertical gravitational.ResultsAIS SPV=7.48±4.86° with a tilt predominance to the right. It is impossible to realize statistical evaluation in this preliminary study. Our results are comparable with those reported in pusher patient.DiscussionThis preliminary study shows a disturbance in the assessment of SPV in the AIS. Disorders of the central integration of somatosensory modality could explain this result.The authors are grateful to the Harps Association's members, for their helpful comments
Lagrangian Reachabililty
We introduce LRT, a new Lagrangian-based ReachTube computation algorithm that
conservatively approximates the set of reachable states of a nonlinear
dynamical system. LRT makes use of the Cauchy-Green stretching factor (SF),
which is derived from an over-approximation of the gradient of the solution
flows. The SF measures the discrepancy between two states propagated by the
system solution from two initial states lying in a well-defined region, thereby
allowing LRT to compute a reachtube with a ball-overestimate in a metric where
the computed enclosure is as tight as possible. To evaluate its performance, we
implemented a prototype of LRT in C++/Matlab, and ran it on a set of
well-established benchmarks. Our results show that LRT compares very favorably
with respect to the CAPD and Flow* tools.Comment: Accepted to CAV 201
Generation and characterization of function-blocking anti-ectodysplasin A (EDA) monoclonal antibodies that induce ectodermal dysplasia.
Development of ectodermal appendages, such as hair, teeth, sweat glands, sebaceous glands, and mammary glands, requires the action of the TNF family ligand ectodysplasin A (EDA). Mutations of the X-linked EDA gene cause reduction or absence of many ectodermal appendages and have been identified as a cause of ectodermal dysplasia in humans, mice, dogs, and cattle. We have generated blocking antibodies, raised in Eda-deficient mice, against the conserved, receptor-binding domain of EDA. These antibodies recognize epitopes overlapping the receptor-binding site and prevent EDA from binding and activating EDAR at close to stoichiometric ratios in in vitro binding and activity assays. The antibodies block EDA1 and EDA2 of both mammalian and avian origin and, in vivo, suppress the ability of recombinant Fc-EDA1 to rescue ectodermal dysplasia in Eda-deficient Tabby mice. Moreover, administration of EDA blocking antibodies to pregnant wild type mice induced in developing wild type fetuses a marked and permanent ectodermal dysplasia. These function-blocking anti-EDA antibodies with wide cross-species reactivity will enable study of the developmental and postdevelopmental roles of EDA in a variety of organisms and open the route to therapeutic intervention in conditions in which EDA may be implicated
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