A computer simulation of digital recording Final development progress report, 29 Dec. 1966 - 29 Dec. 1967

Fourier series digital computer simulation of tape recording process - signal detection in prescence of white Gaussian nois

Autonomes Lernen: ein Prinzip im schulischen Unterricht und in der Lehrerfortbildung:eine Kooperation im Rahmen der Lehrerfort- und -weiterbildung zwischen der Bezirksregierung Münster und der Universität Münster (1998-2001)

Im Rahmen der Lehrerfort- und -weiterbildung zwischen der Bezirksregierung Münster und der Universiät Münster arbeitete die Arbeitsgruppe "Autonomes Lernen im Fremdsprachenunterricht unter Einbeziehung der neuen Medien" drei Jahre eng zusammen. Regelmässige Workshops boten während dieser Zeit der kontinuierlichen, gemeinsamen Arbeit die Möglichkeit des regelmäßigen Austauschs und der Diskussion zwischen den beteiligten Lehrerinnen und Lehrern und uns, der Vertreterin und den Vertretern der Universität. Dabei wurden die Prinzipien des autonomen Lernens auf die Projektarbeit selbst angewendet. Der Beitrag gibt einen kleinen Einblick in den Verlauf der Projektarbeit.</p

On Real Fluid Flow Over Yawed Circular Cylinders

The equations for both the boundary layer and the outer potential flow over a yawed cylinder can be resolved into equations for the crosswise and spanwise velocity components. These components of the boundary layer are evaluated using Sears’ method, and the separation point is found to be uninfluenced by the yaw angle. The potential-flow solutions for the spanwise and crosswise flows are added together to determine vortex patterns behind the cylinder. The approximate direct dependence of the Strouhal number upon the cosine of the yaw angle and/or the drag coefficient upon the square of the cosine, are verified. Experimental determinations of the Strouhal number and visualization of the flow pattern are consistent with the analysis

Assessing methodological quality of Russian clinical practice guidelines and introducing AGREE II instrument in Russia

© 2018 Lienhard et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Background There are multiple organisations in Russia that publish clinical practice guidelines (CPGs). The demand for CPGs and appreciation of their role in healthcare provision has been steadily growing. However, quality and methodology of development of CPGs have not been systematically addressed. Aim To analyse the quality of Russian-produced CPGs for surgical treatment of hepatic-pancreatic-biliary diseases. Methods We searched Russian databases for CPGs, published between 2013 and 2017. We identified 6 relevant documents that met our inclusion criteria. We approached four experts in the field with written and verbal instructions on the use of the AGREE II questionnaire. Results All six CPGs received the highest domain scores for the domain Clarity of Presentation (46%–80%). The lowest domain scores were for the domain Editorial Independence (6%-25%). Overall, the experts put the highest total sum scores to the CPG for treating chronic pancreatitis (70%), while the lowest total sum score was attributed to the CPG for treating acute cholangitis (22%). Conclusions The overall quality of CPGs, as assessed by the four experts with the AGREE II instrument, was low. The highest scoring, best organized and most comprehensive and straightforward CPG was the one for chronic pancreatitis. The AGREE II instrument should be considered for use in Russia by guideline developers to assess existing CPGs and inform the creation of new guidelines

Comprehensive condensation flow regimes in air gap membrane distillation: Visualization and energy efficiency

The thermal performance of air gap membrane distillation (AGMD) desalination is dominated by heat and mass transfer across the air gap between the membrane and the condensing surface. However, little is known about the impact of condensate flow patterns in some design variations of the air gap. In this study, air gap membrane distillation experiments were performed at various inlet temperatures, varying module inclination angle, condensing surface hydrophobicity, and gap spacer design to identify the effect of each on the permeate production rate and thermal efficiency of the system. Additionally, this study is one of the first with enhanced visualization of flow patterns within the air gap itself, by using a transparent, high thermal conductivity sapphire plate as the condenser surface. System-level numerical modeling is used to further understand the impact of these flow regimes on overall energy efficiency, including flux and GOR. A brief review of membrane distillation condensation regimes is provided as well. For tilting the AGMD flat-plate module, permeate flux was barely influenced except at extreme positive angles ( > 80°), and moderate negative angles ( 1 mm). Meanwhile, the hydrophilic surface for small gap sizes ( < 3 mm) often had pinned regions of water around the hydrophilic surface and plastic spacer. Overall, the various results imply that the common assumption of a laminar condensate film poorly describes the flow patterns in real systems for all tilt angles and most spacer designs. Real system performance is likely to be between that of pure AGMD and permeate gap membrane distillation (PGMD) variants, and modeling shows that enhanced condensing in air gaps may improve system energy efficiency significantly, with strong relative advantages at high salinity. Keywords: Membrane distillation; Hydrophobic surface; Air gap; Condensation; Visualizatio

Visualization of droplet condensation in membrane distillation desalination with surface modification: hydrophilicity, hydrophobicity, and wicking spacers

Condensation performance is a key target for improving the energy efficiency of thermal desalination technologies such as air gap membrane distillation (AGMD). This study includes the first visualization of condensation in AGMD, through the use of a high conductivity, transparent sapphire condenser surface. The study examines how flow patterns are affected by several novel modifications, including varied surface hydrophobicity, module tilt angle, and gap spacer design. The experimental results were analyzed with numerical modeling. While the orientation of the mesh spacer, which holds the air gap apart, was found to have no substantial effect on the permeate production rate, the surface's hydrophobicity or hydrophilicity did result in different rates. The hydrophobic surface exhibited fewer droplets bridging the gap, more spherical droplets, and better droplet shedding. For gap sizes less than ~3 mm, the hydrophilic surface frequently had regions of water pinned around the surface itself and the plastic spacer. While the flow patterns observed were more complex than the film condensation typically used to model the process, the simplified numerical modelling yielded good agreement with the data when an adjustment factor was used to account for the gap size

MEDIPS: genome-wide differential coverage analysis of sequencing data derived from DNA enrichment experiments

MOTIVATION: DNA enrichment followed by sequencing is a versatile tool in molecular biology, with a wide variety of applications including genome-wide analysis of epigenetic marks and mechanisms. A common requirement of these diverse applications is a comparison of read coverage between experimental conditions. The amount of samples generated for such comparisons ranges from few replicates to hundreds of samples per condition for epigenome-wide association studies. Consequently, there is an urgent need for software that allows for fast and simple processing and comparison of sequencing data derived from enriched DNA. RESULTS: Here, we present a major update of the R/Bioconductor package MEDIPS, which allows for an arbitrary number of replicates per group and integrates sophisticated statistical methods for the detection of differential coverage between experimental conditions. Our approach can be applied to a diversity of quantitative sequencing data. In addition, our update adds novel functionality to MEDIPS, including correlation analysis between samples, and takes advantage of Bioconductor's annotation databases to facilitate annotation of specific genomic regions. AVAILABILITY AND IMPLEMENTATION: The latest version of MEDIPS is available as version 1.12.0 and part of Bioconductor 2.13. The package comes with a manual containing detailed description of its functionality and is available at http://www.bioconductor.org

EVIDENCES ABOUT HUMAN TICK-BORNE INFECTIONS IN CUBA

Serosurveys for IgG antibodies to Borrelia burgdorferi sensu stricto in a population exposed to tick bites (n = 247) and blood donors (n = 114) were done to assess the prevalence of tick-borne infections in. Seroprevalence of antiborrelial IgG antibodies was estimated in 0.6–7.2 % and 0 % of risk population and blood donors, respectively. While previous expositions to A. phagocytophilum (7.2 %), E. chaffensis (3.6 %) and B. microti (11.5 %) were serologically detected. These reports suggest the presence of tick-borne pathogens in Cuba, nonetheless lacking of further accurate information strongly calls to the need of more deeply studies. Cub

Solving random boundary heat model using the finite difference method under mean square convergence

"This is the peer reviewed version of the following article: Cortés, J. C., Romero, J. V., Roselló, M. D., Sohaly, MA. Solving random boundary heat model using the finite difference method under mean square convergence. Comp and Math Methods. 2019; 1:e1026. https://doi.org/10.1002/cmm4.1026 , which has been published in final form at https://doi.org/10.1002/cmm4.1026. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] This contribution is devoted to construct numerical approximations to the solution of the one-dimensional boundary value problem for the heat model with uncertainty in the diffusion coefficient. Approximations are constructed via random numerical schemes. This approach permits discussing the effect of the random diffusion coefficient, which is assumed a random variable. We establish results about the consistency and stability of the random difference scheme using mean square convergence. Finally, an illustrative example is presented.Spanish Ministerio de Economía y Competitividad. Grant Number: MTM2017-89664-PCortés, J.; Romero, J.; Roselló, M.; Sohaly, M. (2019). Solving random boundary heat model using the finite difference method under mean square convergence. Computational and Mathematical Methods. 1(3):1-15. https://doi.org/10.1002/cmm4.1026S11513Han, X., & Kloeden, P. E. (2017). Random Ordinary Differential Equations and Their Numerical Solution. Probability Theory and Stochastic Modelling. doi:10.1007/978-981-10-6265-0Villafuerte, L., Braumann, C. A., Cortés, J.-C., & Jódar, L. (2010). Random differential operational calculus: Theory and applications. Computers & Mathematics with Applications, 59(1), 115-125. doi:10.1016/j.camwa.2009.08.061Logan, J. D. (2004). Partial Differential Equations on Bounded Domains. Undergraduate Texts in Mathematics, 121-171. doi:10.1007/978-1-4419-8879-9_4Cannon, J. R. (1964). A Cauchy problem for the heat equation. Annali di Matematica Pura ed Applicata, 66(1), 155-165. doi:10.1007/bf02412441LinPPY.On The Numerical Solution of The Heat Equation in Unbounded Domains[PhD thesis].New York NY:New York University;1993.Li, J.-R., & Greengard, L. (2007). On the numerical solution of the heat equation I: Fast solvers in free space. Journal of Computational Physics, 226(2), 1891-1901. doi:10.1016/j.jcp.2007.06.021Han, H., & Huang, Z. (2002). Exact and approximating boundary conditions for the parabolic problems on unbounded domains. Computers & Mathematics with Applications, 44(5-6), 655-666. doi:10.1016/s0898-1221(02)00180-3Han, H., & Huang, Z. (2002). A class of artificial boundary conditions for heat equation in unbounded domains. Computers & Mathematics with Applications, 43(6-7), 889-900. doi:10.1016/s0898-1221(01)00329-7Strikwerda, J. C. (2004). Finite Difference Schemes and Partial Differential Equations, Second Edition. doi:10.1137/1.9780898717938Kloeden, P. E., & Platen, E. (1992). Numerical Solution of Stochastic Differential Equations. doi:10.1007/978-3-662-12616-5Øksendal, B. (2003). Stochastic Differential Equations. Universitext. doi:10.1007/978-3-642-14394-6Holden, H., Øksendal, B., Ubøe, J., & Zhang, T. (2010). Stochastic Partial Differential Equations. doi:10.1007/978-0-387-89488-1El-Tawil, M. A., & Sohaly, M. A. (2012). Mean square convergent three points finite difference scheme for random partial differential equations. Journal of the Egyptian Mathematical Society, 20(3), 188-204. doi:10.1016/j.joems.2012.08.017Cortés, J.-C., Navarro-Quiles, A., Romero, J.-V., Roselló, M.-D., & Sohaly, M. A. (2018). Solving the random Cauchy one-dimensional advection–diffusion equation: Numerical analysis and computing. Journal of Computational and Applied Mathematics, 330, 920-936. doi:10.1016/j.cam.2017.02.001Cortés, J. C., Jódar, L., Villafuerte, L., & Villanueva, R. J. (2007). Computing mean square approximations of random diffusion models with source term. Mathematics and Computers in Simulation, 76(1-3), 44-48. doi:10.1016/j.matcom.2007.01.020Cortés, J. C., Jódar, L., & Villafuerte, L. (2009). Random linear-quadratic mathematical models: Computing explicit solutions and applications. Mathematics and Computers in Simulation, 79(7), 2076-2090. doi:10.1016/j.matcom.2008.11.008Henderson, D., & Plaschko, P. (2006). Stochastic Differential Equations in Science and Engineering. doi:10.1142/580

Global analysis of the TRAPPIST Ultra-Cool Dwarf Transit Survey

ABSTRACT We conducted a global analysis of the TRAPPIST Ultra-Cool Dwarf Transit Survey – a prototype of the SPECULOOS transit search conducted with the TRAPPIST-South robotic telescope in Chile from 2011 to 2017 – to estimate the occurrence rate of close-in planets such as TRAPPIST-1b orbiting ultra-cool dwarfs. For this purpose, the photometric data of 40 nearby ultra-cool dwarfs were reanalysed in a self-consistent and fully automated manner starting from the raw images. The pipeline developed specifically for this task generates differential light curves, removes non-planetary photometric features and stellar variability, and searches for transits. It identifies the transits of TRAPPIST-1b and TRAPPIST-1c without any human intervention. To test the pipeline and the potential output of similar surveys, we injected planetary transits into the light curves on a star-by-star basis and tested whether the pipeline is able to detect them. The achieved photometric precision enables us to identify Earth-sized planets orbiting ultra-cool dwarfs as validated by the injection tests. Our planet-injection simulation further suggests a lower limit of 10 per cent on the occurrence rate of planets similar to TRAPPIST-1b with a radius between 1 and 1.3 R⊕ and the orbital period between 1.4 and 1.8 d.</jats:p