228 research outputs found
H
This paper is concerned with the H∞ filtering problem
for networked systems with bounded measurement missing.
A switched linear system model is proposed to describe the
considered filtering error system. A sufficient condition is
derived for the filtering error system to be exponentially stable
and achieve a prescribed H∞ filtering performance level.
The obtained condition establishes quantitative relations among
the H∞ performance level and two parameters
characterizing the measurement missing, namely, the measurement
missing rate bound and the maximal number of consecutive
measurement missing. A convex optimization problem is presented to
design the linear H∞ filters. Finally, an illustrative
example is given to show the effectiveness of the proposed
results
The Milky Way's rotation curve out to 100 kpc and its constraint on the Galactic mass distribution
The rotation curve (RC) of the Milky Way out to 100 kpc has been
constructed using 16,000 primary red clump giants (PRCGs) in the outer
disk selected from the LSS-GAC and the SDSS-III/APOGEE survey, combined with
5700 halo K giants (HKGs) selected from the SDSS/SEGUE survey. To derive
the RC, the PRCG sample of the warm disc population and the HKG sample of halo
stellar population are respectively analyzed using a kinematical model allowing
for the asymmetric drift corrections and re-analyzed using the spherical Jeans
equation along with measurements of the anisotropic parameter currently
available. The typical uncertainties of RC derived from the PRCG and HKG
samples are respectively 5-7 km/s and several tens km/s. We determine a
circular velocity at the solar position, = 240 6 km/s and an
azimuthal peculiar speed of the Sun, = 12.1 7.6 km/s, both in
good agreement with the previous determinations. The newly constructed RC has a
generally flat value of 240 km/s within a Galactocentric distance of 25 kpc
and then decreases steadily to 150 km/s at 100 kpc. On top of this
overall trend, the RC exhibits two prominent localized dips, one at
11 kpc and another at 19 kpc. From the newly constructed RC,
combined with other constraints, we have built a parametrized mass model for
the Galaxy, yielding a virial mass of the Milky Way's dark matter halo of
and a local dark matter
density, GeV cm.Comment: MNRAS accepted, 18 pages, 15 figures, 4 table
A curve model for association of serum homocysteine with carotid artery hemodynamics
Purpose: To investigate the correlation between carotid artery hemodynamics and serum homocysteine.Methods: A total of 894 participants made up of 439 male (49.11 %) and 455 female (50.89 %) from Ma’anshan, China, enrolled in the cross-sectional study. Data collection included demographics, blood sample and carotid ultrasonography. Piecewise linear regression analysis was used to analyze the relationship between serum homocysteine and carotid artery hemodynamics.Results: Homocysteine (Hcy) levels were divided into four groups by quartiles. The populations of the groups were 226, 220, 222, 226; and their mean ages were 56.52 ± 10.49, 62.27 ± 10.06, 63.42 ± 9.81 and 65.38 ± 10.56 years, respectively. After adjustment for blood biochemical and demographics factors, U-shaped and S-shaped curves were as observed between Hcy and carotid artery hemodynamics. The adjusted regression analysis showed that the threshold values of Hcy with end diastolic velocity (EDV) of right common carotid artery (CCA) were 12.50 and 19.00, while for the EDV of right internal carotid artery (ICA), the values were 11.50 and 22.00. U-shaped curves were observed between Hcy and peak systolic velocity (PSV) of left CCA, EDV of left CCA, PSV of left ICA and EDV of left ICA. The threshold values of Hcy with PSV of left CCA, EDV of left CCA, PSV of left ICA and EDV of left ICA were 14.00, 14.00, 14.00 and 13.50, respectively.Conclusion: These results indicate that a significant correlation exists between homocysteine at different concentrations and carotid artery hemodynamics.Keywords: Homocysteine, Hemodynamics, End diastolic velocity, Peak systolic velocit
- …