1,721,102 research outputs found
Laboratory tests to monitoring physiological pregnancy|Il ruolo del laboratorio nel monitoraggio della gravidanza fisiologica
No full textA Note on Delay Coordinates for Locally Observable Analytic Systems
Full text linkIn this short note, the problem of locally reconstructing the state of a nonlinear system is studied. To avoid computational difficulties arising in the numerical differentiation of the output, the so-called delay coordinates are considered. The assumptions of analyticity and (local) observability of the system are shown to imply that a family of mappings, induced by the delay coordinates and parameterized by a time delay parameter, gives a local diffeomorphism for generic values of such delay parameter on a certain set. A worked-out example illustrates the result
Automated Mindray CL-1200i chemiluminescent assays of renin and aldosterone for the diagnosis of primary aldosteronism
Full text linkMoments of random variables: a system-theoretic interpretation
Full text linkMoments of continuous random variables with a
probability density function which can be represented as the
impulse response of a linear time-invariant system are studied.
Under some assumptions, the moments of the random variable
are characterised in terms of the solution of a Sylvester equation
and of the steady-state output response of an interconnected
system. This allows to interpret well-known notions and results
of probability theory and statistics in the language of system
theory, including the notion of moment generating function, the
sum of independent random variables and the notion of mixture
distribution
A geometric characterization of the persistence of excitation condition for the solutions of autonomous systems
Full text linkThe persistence of excitation of signals generated by time-invariant, autonomous, linear, and nonlinear systems is studied using a geometric approach. A rank condition is shown to be equivalent, under certain assumptions, to the persistence of excitation of the solutions of the class of systems considered, both in the discrete-time and in the continuous-time settings. The rank condition is geometric in nature and can be checked a priori, i.e. without knowing explicitly the solutions of the system, for almost periodic systems. The significance of the ideas and tools presented is illustrated by means of simple examples. Applications to model reduction from input-output data and stability analysis of skew-symmetric systems are also discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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