166 research outputs found

    Разработка системы управления электротехнологической установкой на основе беспроводного интерфейса

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    Развитие микроконтроллерной техники дает возможность создать беспроводное устройство управления ЭТУ, которое позволило бы решить ряд проблем, возникающих в проводных системах, и сделало бы работу оператора более комфортной и безопасной. Объектом исследования является система беспроводного управления макетом электротехнологической установки (ЭТУ). Цель работы – разработка беспроводной системы управления макетом ЭТУ. В результате исследования была разработана работоспособная система управления ЭТУ состоящая из интерфейса управления и макета ЭТУ.The development of microcontroller technology makes it possible to create a wireless control device for an electrical installation, which would solve a number of problems arising in wired systems, and would make the operator's work more comfortable and safe. The object of the research is the system of wireless control of the layout of the electrotechnological installation of the electrotechnical installation. The purpose of the work is to develop a wireless control system for the layout of an electrotechnical installation. As a result of the study, a workable control system for an electrical installation was developed, consisting of a control interface and a model for an electrical installation

    A review of Monte Carlo simulations of polymers with PERM

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    In this review, we describe applications of the pruned-enriched Rosenbluth method (PERM), a sequential Monte Carlo algorithm with resampling, to various problems in polymer physics. PERM produces samples according to any given prescribed weight distribution, by growing configurations step by step with controlled bias, and correcting "bad" configurations by "population control". The latter is implemented, in contrast to other population based algorithms like e.g. genetic algorithms, by depth-first recursion which avoids storing all members of the population at the same time in computer memory. The problems we discuss all concern single polymers (with one exception), but under various conditions: Homopolymers in good solvents and at the Θ\Theta point, semi-stiff polymers, polymers in confining geometries, stretched polymers undergoing a forced globule-linear transition, star polymers, bottle brushes, lattice animals as a model for randomly branched polymers, DNA melting, and finally -- as the only system at low temperatures, lattice heteropolymers as simple models for protein folding. PERM is for some of these problems the method of choice, but it can also fail. We discuss how to recognize when a result is reliable, and we discuss also some types of bias that can be crucial in guiding the growth into the right directions.Comment: 29 pages, 26 figures, to be published in J. Stat. Phys. (2011

    Sensitivity of the early life stages of a mayfly to fine sediment and orthophosphate levels

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    The ecological effects of interacting stressors within lotic ecosystems have been widely acknowledged. In particular, the ecological effects of elevated fine sediment inputs and phosphate have been identified as key factors influencing faunal community structure and composition. However, while knowledge regarding adult and larval life stage responses to environmental stressors has grown, there has been very limited research on their eggs. In this study, the eggs of the mayfly Serratella ignita (Ephemerellidae: Ephemeroptera) were collected and incubated in laboratory aquaria to hatching under differing concentrations of inert suspended sediment (SS) and orthophosphate (OP), individually and in combination. Results indicate that SS and OP have greater effects on egg hatching in combination than when either were considered in isolation. SS displayed a greater effect on egg survival than OP in isolation or when OP was added to elevated SS treatments. Egg mortality in control treatments was around 6% compared to 45% in treatments with 25 mg 1⁻¹ SS and 52% in 0.3 mg 1⁻¹ OP treatments. Even relatively modest levels of each stressor (10 mg 1⁻¹ SS; 0.1 mg 1⁻¹ OP), below national legal thresholds, had significant effects on egg survival to hatching. The results support calls for legal levels of SS to be reassessed and suggest that more research is required to assess the impacts of pollution on invertebrate egg development given their different sensitivity and exposure pathways compared to other life stages

    Flyover Noise Measurements of a Spiraling Noise Abatement Approach Procedure

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    DLR is investigating alternative low-noise approach procedures. One such procedure involves approaching the airport at a considerably higher altitude compared with standard landing trajectories, followed by a spiraling descent (helix flight path) shortly before the runway threshold. In this way, high ground noise levels by approaching aircraft are dislocated away from the common approach path and concentrated in the area near the helix path, i. e. in direct vicinity of the airport. Ground noise levels along the entire flight path prior to the helix are significantly reduced. The effectiveness of this procedure, referred to as Helical Noise Abatement Procedure (HeNAP), has been quantified by means of computational simulation analyses. These analyses also focused on aspects such as increased fuel burn and the occurrence of multiple noise events below the helix. In June 2009 a new DLR autopilot especially capable of tracking curved flight path trajectories was flight tested. Three HeNAPs were included in the flight plan, as well as standard and steep landing approaches. In addition, dedicated fly-over noise measurements were organized, supported by RWTH Aachen University. Twelve ground microphones have been installed along the common approach path and the helical flight segment. Despite adverse wind conditions at the only available test day, the measured data confirm the predicted noise dislocation effects. High noise levels have been limited to observer locations around the helix. DLR noise prediction methods have been compared with the experimental data. Predicted trends and noise dislocation effects are in good agreement with the measurements whereas the absolute numerical values show discrepancies. The flight test was closely accompanied by a R&D member of DFS to study the impact of spiraling procedures on ATM integration and air traffic controller workload, e. g. increased interaction with the pilots. Obviously, a spiraling approach procedure would not be implemented into the existing air traffic scenario with its common approach paths and highly frequented airports. The operational and economic environment still need more detailed investigation. Helical approaches become more feasible for implementation at small, low-frequented regional airports or during night hours to avoid possible noise related curfews

    RNA-binding proteins as mediators of circadian clock output in Arabidopsis thaliana

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    Staiger D, Streitner C, Lummer M, Schöning JC, Alfano J. RNA-binding proteins as mediators of circadian clock output in Arabidopsis thaliana. In: Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. Comparative Biochemistry and Physiology A - Molecular & Integrative Physiology. Vol 150. Elsevier; 2008: S152-S153

    Handling of Non-Periodic Contra Rotating Open Rotor Data

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    In this contribution, we present two different concepts to handle the non-periodic nature of Contra Rotating Open Rotor (CROR) if the front and the aft rotor rotate with a slightly different rotational speed. The first procedure that is presented consists of a correction matrix applied to the source data used in the DLR FWH-code APSIM+. For periodic data the correction matrix reduces to the identity matrix, thereby recovering the standard Fourier transformation. The second method is based on the Vanicek approximation, and consists of a successive least-square approximation of non-periodic data. The developed methods are tested with artificially generated data, illustrating the ability to accurately representing non-periodic data. A comparison between the two methods shows that the first method is more accurate than the Vanicek approximation. Preliminary results on actual non-periodic CROR data reveals the influence of the non-periodic correction as compared to uncorrected data, i.e., differences ranging up to 10 dB are seen for the considered cases

    Regulation of pri-miRNA processing by the hnRNP-like protein AtGRP7 in Arabidopsis

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    The hnRNP-like glycine-rich RNA-binding protein AtGRP7 regulates pre-mRNA splicing in Arabidopsis. Here we used small RNA-seq to show that AtGRP7 also affects the miRNA inventory. AtGRP7 overexpression caused a significant reduction in the level of 30 miRNAs and an increase for 14 miRNAs with a minimum log2 fold change of ±0.5. Overaccumulation of several pri-miRNAs including pri-miR398b, pri-miR398c, pri-miR172b, pri-miR159a and pri-miR390 at the expense of the mature miRNAs suggested that AtGRP7 affects pri-miRNA processing. Indeed, RNA immunoprecipitation revealed that AtGRP7 interacts with these pri-miRNAs in vivo. Mutation of an arginine in the RNA recognition motif abrogated in vivo binding and the effect on miRNA and pri-miRNA levels, indicating that AtGRP7 inhibits processing of these pri-miRNAs by direct binding. In contrast, pri-miRNAs of selected miRNAs that were elevated or not changed in response to high AtGRP7 levels were not bound in vivo. Reduced accumulation of miR390, an initiator of trans-acting small interfering RNA (ta-siRNA) formation, also led to lower TAS3 ta-siRNA levels and increased mRNA expression of the target AUXIN RESPONSE FACTOR4. Furthermore, AtGRP7 affected splicing of pri-miR172b and pri-miR162a. Thus, AtGRP7 is an hnRNP-like protein with a role in processing of pri-miRNAs in addition to its role in pre-mRNA splicing
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