8,876 research outputs found
On the design of optimal input signals in system identification
The problem of designing optimal inputs in the identification of linear systems with unknown random parameters is considered using a Bayesian approach. The information matrix, which is positive definite for the class of systems analyzed, gives a measure of performance for the system inputs. The computation of the optimal closed-loop input mappings is shown to be a nontrivial exercise in adaptive control. Deterministic optimal inputs are shown to be easily computable. Numerical examples are given. A Kalman filter is used to estimate the parameters. A necessary condition for the Kalman filter not to diverge when applying linear feedback is also given
A differential diagnosis of inherited endocrine tumors and their tumor counterparts
Inherited endocrine tumors have been increasingly recognized in clinical practice, although some difficulties still exist in differentiating these conditions from their sporadic endocrine tumor counterparts. Here, we list the 12 main topics that could add helpful information and clues for performing an early differential diagnosis to distinguish between these conditions. The early diagnosis of patients with inherited endocrine tumors may be performed either clinically or by mutation analysis in at-risk individuals. Early detection usually has a large impact in tumor management, allowing preventive clinical or surgical therapy in most cases. Advice for the clinical and surgical management of inherited endocrine tumors is also discussed. In addition, recent clinical and genetic advances for 17 different forms of inherited endocrine tumors are briefly reviewed
The Benefits of Peer Review and a Multisemester Capstone Writing Series on Inquiry and Analysis Skills in an Undergraduate Thesis.
This study examines the relationship between the introduction of a four-course writing-intensive capstone series and improvement in inquiry and analysis skills of biology senior undergraduates. To measure the impact of the multicourse write-to-learn and peer-review pedagogy on student performance, we used a modified Valid Assessment of Learning in Undergraduate Education rubric for Inquiry and Analysis and Written Communication to score senior research theses from 2006 to 2008 (pretreatment) and 2009 to 2013 (intervention). A Fisher-Freeman-Halton test and a two-sample Student's t test were used to evaluate individual rubric dimensions and composite rubric scores, respectively, and a randomized complete block design analysis of variance was carried out on composite scores to examine the impact of the intervention across ethnicity, legacy (e.g., first-generation status), and research laboratory. The results show an increase in student performance in rubric scoring categories most closely associated with science literacy and critical-thinking skills, in addition to gains in students' writing abilities
Stern-Gerlach Entanglement in Spinor Bose-Einstein Condensates
Entanglement of spin and position variables produced by spatially
inhomogeneous magnetic fields of Stern-Gerlach type acting on spinor
Bose-Einstein condensates may lead to interference effects at the level of
one-boson densities. A model is worked out for these effects which is amenable
to analytical calculation for gaussian shaped condensates. The resulting
interference effects are sensitive to the spin polarization properties of the
condensate.Comment: 9 pages, 2 figure
The UNAM-KIAS Catalog of Isolated Galaxies
A new catalog of isolated galaxies from The Sloan Digital Sky Survey (DR5) is
presented. 1520 isolated galaxies were found in 1.4 steradians of sky. The
selection criteria in this so called UNAM-KIAS catalog was implemented from a
variation on the criteria developed by Karachentseva 1973 including full
redshift information. Through an image processing pipeline that takes advantage
from the high resolution (~ 0.4 ''/pix) and high dynamic range of the SDSS
images, a uniform g band morphological classification for all these galaxies is
presented. We identify 80% (SaSm) spirals (50% later than Sbc types) on one
hand, and a scarce population of early-type E(6.5%) and S0(8%) galaxies
amounting to 14.5% on the other hand. This magnitude-limited catalog is ~ 80%
complete at 16.5, 15.6, 15.0, 14.6 and 14.4 magnitudes in the ugriz bands
respectively. Some representative physical properties including SDSS magnitudes
and color distributions, color-color diagrams, absolute magnitude-color, and
concentration-color diagrams as a function of morphological type are presented.
The UNAM-KIAS Morphological Atlas is also released along with this paper. For
each galaxy of type later than Sa, a mosaic is presented that includes: (1) a
g-band logarithmic image, (2) a g band filtered-enhanced image where a Gaussian
kernel of various sizes was applied and (3) an RGB color image from the SDSS
database. For E/S0/Sa galaxies, in addition to the images in (1), (2) and (3),
plots of r band surface brightness and geometric profiles (ellipticity,
Position Angle PA and A4/B4 coefficients of the Fourier series expansions of
deviations of a pure ellipse) are provided...Comment: 40 pages, 17 figures and 3 table
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