Improving Transient Performance of Adaptive Control Architectures using Frequency-Limited System Error Dynamics

We develop an adaptive control architecture to achieve stabilization and command following of uncertain dynamical systems with improved transient performance. Our framework consists of a new reference system and an adaptive controller. The proposed reference system captures a desired closed-loop dynamical system behavior modified by a mismatch term representing the high-frequency content between the uncertain dynamical system and this reference system, i.e., the system error. In particular, this mismatch term allows to limit the frequency content of the system error dynamics, which is used to drive the adaptive controller. It is shown that this key feature of our framework yields fast adaptation with- out incurring high-frequency oscillations in the transient performance. We further show the effects of design parameters on the system performance, analyze closeness of the uncertain dynamical system to the unmodified (ideal) reference system, discuss robustness of the proposed approach with respect to time-varying uncertainties and disturbances, and make connections to gradient minimization and classical control theory.Comment: 27 pages, 7 figure

Entanglement for all quantum states

It is shown that a state that is factorizable in the Hilbert space corresponding to some choice of degrees of freedom, becomes entangled for a different choice of degrees of freedom. Therefore, entanglement is not a special case but is ubiquitous in quantum systems. Simple examples are calculated and a general proof is provided. The physical relevance of the change of tensor product structure is mentioned.Comment: 9 page

Understanding the shape of the galaxy two-point correlation function at z ≃ 1 in the COSMOS field

We investigate how the shape of the galaxy two-point correlation function as measured in the zCOSMOS survey depends on local environment, quantified in terms of the density contrast on scales of 5 h^(−1) Mpc. We show that the flat shape previously observed at redshifts between z= 0.6 and 1 can be explained by this volume being simply 10 per cent overabundant in high-density environments, with respect to a universal density probability distribution function. When galaxies corresponding to the top 10 per cent tail of the distribution are excluded, the measured w_(p)(r_(p)) steepens and becomes indistinguishable from Lambda cold dark matter (ΛCDM) predictions on all scales. This is the same effect recognized by Abbas & Sheth in the Sloan Digital Sky Survey (SDSS) data at z ≃ 0 and explained as a natural consequence of halo–environment correlations in a hierarchical scenario. Galaxies living in high-density regions trace dark matter haloes with typically higher masses, which are more correlated. If the density probability distribution function of the sample is particularly rich in high-density regions because of the variance introduced by its finite size, this produces a distorted two-point correlation function. We argue that this is the dominant effect responsible for the observed ‘peculiar’ clustering in the COSMOS field

Evaluating First-Generation Students’ Career Readiness

Research shows that first-generation students have historically had less guidance and resources to support their educational attainment and career development (Tate et al., 2015). This has resulted in considerable growth in the amount of support systems, programs, and services implemented by educational institutions across the United States to help first-generation college students thrive in higher education and their future careers. This study sought to improve my understanding of the career readiness of first-generation students at USD. By engaging with and gathering data from first-generation students, I have greater insight about ways of supporting first-generation students’ career readiness and vocational confidence through heightened support from the Career Development Center in navigating career resources and processes. Themes that arose include social and familial pressures, uncertainty, and unfamiliarity. Recommendations include demystifying the meaning of career readiness, tailoring programming and outreach efforts, and implementing resource-specific workshops

Lamellar Structures of MUC2-Rich Mucin: A Potential Role in Governing the Barrier and Lubricating Functions of Intestinal Mucus

Mucus is a ubiquitous feature of mammalian wet epithelial surfaces, where it lubricates and forms a selective barrier that excludes a range of particulates, including pathogens, while hosting a diverse commensal microflora. The major polymeric component of mucus is mucin, a large glycoprotein formed by several MUC gene products, with MUC2 expression dominating intestinal mucus. A satisfactory answer to the question of how these molecules build a dynamic structure capable of playing such a complex role has yet to be found, as recent reports of distinct layers of chemically identical mucin in the colon and anomalously rapid transport of nanoparticles through mucus have emphasized. Here we use atomic force microscopy (AFM) to image a MUC2-rich mucus fraction isolated from pig jejunum. In the freshly isolated mucin fraction, we find direct evidence for trigonally linked structures, and their assembly into lamellar networks with a distribution of pore sizes from 20 to 200 nm. The networks are two-dimensional, with little interaction between lamellae. The existence of persistent cross-links between individual mucin polypeptides is consistent with a non-self-interacting lamellar model for intestinal mucus structure, rather than a physically entangled polymer network. We only observe collapsed entangled structures in purified mucin that has been stored in nonphysiological conditions

Euclid preparation: XI. Mean redshift determination from galaxy redshift probabilities for cosmic shear tomography

The analysis of weak gravitational lensing in wide-field imaging surveys is considered to be a major cosmological probe of dark energy. Our capacity to constrain the dark energy equation of state relies on an accurate knowledge of the galaxy mean redshift ⟨z⟩. We investigate the possibility of measuring ⟨z⟩ with an accuracy better than 0.002 (1 + z) in ten tomographic bins spanning the redshift interval 0.2  99.8%. The zPDF approach can also be successful if the zPDF is de-biased using a spectroscopic training sample. This approach requires deep imaging data but is weakly sensitive to spectroscopic redshift failures in the training sample. We improve the de-biasing method and confirm our finding by applying it to real-world weak-lensing datasets (COSMOS and KiDS+VIKING-450)

Markov chain Monte Carlo analyses of the flux ratios of B, Be and Li with the DRAGON2 code

Recent cosmic-ray measurements are challenging our models of propagation in the Galaxy. A good characterization of the secondary cosmic rays (B, Be, Li and sub-iron species) is crucial to constrain these models and exploit the precision of modern CR experiments. In this work, a Markov chain Monte Carlo analysis has been implemented to fit the experimental flux ratios between B, Be and Li and their flux ratios to the primary nuclei C and O. We have fitted the data using two different parametrizations for the spallation cross sections. The uncertainties in the evaluation of the spectra of these secondary cosmic rays, due to spallation cross sections, have been considered by introducing scale factors as nuisance parameters. We have also tested two different formulations for the diffusion coefficient, which differ in the origin of the high energy hardening of cosmic rays. Additionally, two different approaches are used to scale the cross sections, one based on a combined analysis of all the species ("combined" analysis) and the other reproducing the high energy spectra of the secondary-to-secondary flux ratios of Be/B, Li/B, Li/Be ("scaled" analysis). This allows us to make a better comparison between the propagation parameters inferred from the cross sections parametrizations tested in this work. This novel analysis has been successfully implemented using the numerical code DRAGON2 to reproduce the cosmic-ray nuclei data up to $Z=14$ from the AMS-02 experiment. It is found that the ratios of Li favor a harder spectral index of the diffusion coefficient, but compatible with the other ratios inside the observed $2\sigma$ uncertainties. In addition, it is shown that, including these scale factors, the secondary-to-primary flux ratios can be simultaneously reproduced.Comment: 27 pages, 10 figures, 9 table

Occupational accidents and diseases in small animal practice, frequency of adoption of safety practices

A cross-sectional study was performed in N=23 small animal practitioners in the city of Mendoza,\nArgentina, by means of personal interviews using a structured questionnaire. Statistical analysis\nincluded Fisher?s exact test and Student?s t test. As much as 30.4% did not have any medical coverage\nand 47.8% had suffered some zoonotic disease, mainly external parasites. All were injured in labore\n(mainly needlesticks, bites and scratches). Gloves were the most used protective element in labore,\nbut the frequency of use of other elements was low. Only 23.1% of those working in radiology\n(n=13) were licensed, 38.5% were registered by the health service and none used a dosimeter. Young\nand female veterinarians adopted protective practices more frequently than experienced and male\nveterinarians.Fil: Gómez de la Torre, N. Universidad Juan Agustín Maza. Facultad de Ciencias Veterinarias y Ambientales; ArgentinaFil: Tarabla, H.D. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaSe efectuó un estudio transversal en N=23 veterinarios de pequeños animales en la ciudad de Mendoza,\nArgentina, mediante cuestionario estructurado en entrevistas personales. El análisis estadístico incluyó\ntest exacto de Fisher y t de Student. El 30,4% de los profesionales carecía de cobertura médica.\nEl 47,8% manifestó haber padecido alguna zoonosis, principalmente parasitosis externas y todos\nsufrieron lesiones in labore, generalmente heridas punzantes, mordeduras y rasguños. Los guantes\nfueron los elementos de protección personal (EPP) más utilizados in labore, pero la frecuencia de\nuso de otros elementos fue baja. Sólo el 23,1% de quienes hacían radiología (n=13) tenía licencia\nsanitaria habilitante, el 38,5% estaba inscripto en el servicio de salud y ninguno utilizaba dosímetro.\nLos veterinarios más jóvenes y las mujeres tendieron a adoptar prácticas seguras con una frecuencia\nsignificativamente mayor