695 research outputs found
Detecting Topology Variations in Dynamical Networks
This paper considers the problem of detecting topology variations in
dynamical networks. We consider a network whose behavior can be represented via
a linear dynamical system. The problem of interest is then that of finding
conditions under which it is possible to detect node or link disconnections
from prior knowledge of the nominal network behavior and on-line measurements.
The considered approach makes use of analysis tools from switching systems
theory. A number of results are presented along with examples
Switching Control for Parameter Identifiability of Uncertain Systems
This paper considers the problem of identifying the parameters of an
uncertain linear system by means of feedback control. The problem is approached
by considering time-varying controllers. It is shown that even when the
uncertainty set is not finite, parameter identifiability can be generically
ensured by switching among a finite number of linear time-invariant
controllers. The results are shown to have several implications, ranging from
fault detection and isolation to adaptive and supervisory control. Practical
aspects of the problem are also discussed in details
Promotion of proliferation and metastasis of hepatocellular carcinoma by LncRNA00673 based on the targeted-regulation of notch signaling pathway
we read with great interest the paper by Dr. Chen et al1, recently published in European
Review for Medical and Pharmacological Sciences and titled ‘‘Promotion of proliferation and
metastasis of hepatocellular carcinoma by LncRNA00673 based on the targeted-regulation
of notch signaling pathway’’. Authors concluded that lncRNA00673 is highly expressed and
may be a potential target for the treatment of Hepatocellular Carcinoma (HCC). Moreover,
according to authors, it can promote the proliferation and metastasis of HCC by the regulation
of Notch signaling pathway. We congratulate the authors for their interesting work
A Comparison between Position-Based and Image-Based Dynamic Visual Servoings in the Control of a Translating Parallel Manipulator
Two different visual servoing controls have been developed to govern a translating parallel manipulator with an eye-in-hand configuration, That is, a position-based and an image-based controller. The robot must be able to reach and grasp a target randomly positioned in the workspace; the control must be adaptive to compensate motions of the target in the 3D space. The trajectory planning strategy ensures the continuity of the velocity vector for both PBVS and IBVS controls, whereas a replanning event is needed. A comparison between the two approaches is given in terms of accuracy, fastness, and stability in relation to the robot peculiar characteristics
Absolute calibration and beam reconstruction of MITO (a ground-based instrument in the millimetric region)
An efficient sky data reconstruction derives from a precise characterization
of the observing instrument. Here we describe the reconstruction of
performances of a single-pixel 4-band photometer installed at MITO (Millimeter
and Infrared Testagrigia Observatory) focal plane. The strategy of differential
sky observations at millimeter wavelengths, by scanning the field of view at
constant elevation wobbling the subreflector, induces a good knowledge of beam
profile and beam-throw amplitude, allowing efficient data recovery. The
problems that arise estimating the detectors throughput by drift scanning on
planets are shown. Atmospheric transmission, monitored by skydip technique, is
considered for deriving final responsivities for the 4 channels using planets
as primary calibrators.Comment: 14 pages, 6 fiugres, accepted for pubblication by New Astronomy (25
March
Kinetic Inductance Detectors for the OLIMPO experiment: design and pre-flight characterization
We designed, fabricated, and characterized four arrays of horn--coupled,
lumped element kinetic inductance detectors (LEKIDs), optimized to work in the
spectral bands of the balloon-borne OLIMPO experiment. OLIMPO is a 2.6 m
aperture telescope, aimed at spectroscopic measurements of the
Sunyaev-Zel'dovich (SZ) effect. OLIMPO will also validate the LEKID technology
in a representative space environment. The corrected focal plane is filled with
diffraction limited horn-coupled KID arrays, with 19, 37, 23, 41 active pixels
respectively at 150, 250, 350, and 460GHz. Here we report on the full
electrical and optical characterization performed on these detector arrays
before the flight. In a dark laboratory cryostat, we measured the resonator
electrical parameters, such as the quality factors and the electrical
responsivities, at a base temperature of 300mK. The measured average
resonator s are 1.7, 7.0, 1.0, and
1.0 for the 150, 250, 350, and 460GHz arrays, respectively.
The average electrical phase responsivities on resonance are 1.4rad/pW,
1.5rad/pW, 2.1rad/pW, and 2.1rad/pW; the electrical noise
equivalent powers are 45, 160,
80, and 140, at 12 Hz. In the OLIMPO
cryostat, we measured the optical properties, such as the noise equivalent
temperatures (NET) and the spectral responses. The measured NETs are
, , ,
and , at 12 Hz; under 78, 88, 92, and 90 mK
Rayleigh-Jeans blackbody load changes respectively for the 150, 250, 350, and
460 GHz arrays. The spectral responses were characterized with the OLIMPO
differential Fourier transform spectrometer (DFTS) up to THz frequencies, with
a resolution of 1.8 GHz.Comment: Published on JCA
Search for distortions in the spectrum of the Cosmic Microwave Radiation
We present preliminary results of TRIS, an experiment dedicated to the search
of deviations from a pure planckian distribution in the spectrum of the Cosmic
Microwave Background at frequencies close to 1 GHzComment: 9 pages, in press on the Proc. of the 3rd Sakharov Conf. - Moscow
200
Cosmic Microwave Background Temperature at Galaxy Clusters
We have deduced the cosmic microwave background (CMB) temperature in the Coma
cluster (A1656, ), and in A2163 () from spectral
measurements of the Sunyaev-Zel'dovich (SZ) effect over four passbands at radio
and microwave frequencies. The resulting temperatures at these redshifts are
K and K, respectively. These values confirm the expected
relation , where K is the value
measured by the COBE/FIRAS experiment. Alternative scaling relations that are
conjectured in non-standard cosmologies can be constrained by the data; for
example, if or , then
and (at 95% confidence). We
briefly discuss future prospects for more precise SZ measurements of at
higher redshifts.Comment: 13 pages, 1 figure, ApJL accepted for publicatio
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