We simulated the REA system with dynamic deadband to study numerical value and the effect of atmospheric conditions on the empirical constant beta which relates vertical flux to concentration difference between updrafts and downdrafts. We found that the value of beta depends only weakly on the friction velocity and atmospheric stability. In agreement with previous studies, the median value obtained for a system with dynamic deadband proportional to 0.5 times the running mean of the standard deviation of vertical wind speed was beta=0.42+/-0.03. For a single half-hour measurement one has to consider the large uncertainty of +/-0.2. According to our study, the dynamic deadband enables the use of a constant value of beta in flux calculation.
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http://dx.doi.org/10.1016/j.envpol.2007.06.071 | DOI Listing |
Sci Rep
November 2024
ENET Centre, VSB-Technical University of Ostrava, Ostrava, 708 00, Czech Republic.
The imbalance between generated power and load demand often causes unwanted fluctuations in the frequency and tie-line power changes within a power system. To address this issue, a control process known as load frequency control (LFC) is essential. This study aims to optimize the parameters of the LFC controller for a two-area power system that includes a reheat thermal generator and a photovoltaic (PV) power plant.
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July 2022
Electrical and Robotic Engineering, Shahrood University of Technology, Shahrood, Iran.
Presence of nonlinear factors, such as stiction, hysteresis, and deadband, in a control valve imposes limitations on the performance of the control loop. The importance of assessing the nonlinear conditions of a control valve and detecting its possible defects is a key issue in monitoring performance. Because, this may severely impair the performance of the loop and have a direct impact on the product quality.
View Article and Find Full Text PDFSensors (Basel)
February 2017
School of Industrial Engineering, Campus Lagoas-Marcosende, 36310 Vigo, Spain.
This paper investigates the dynamic selection of an appropriate threshold for basic Send-on-Delta (SoD) sampling strategies, given an available transmission rate to reduce the signal tracking-error. The paper formulates the error-reduction principle and proposes an algorithm that calculates, in real time, the amplitude threshold value (also called delta value) for a desired mean transmission rate. The algorithm is implemented to be computed in a Send-on-Delta driver and is tested with three signals that match the step response of a second order control system.
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May 2012
Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH, USA.
Mathematical models of chronic myeloid leukemia (CML) cell population dynamics are being developed to improve CML understanding and treatment. We review such models in light of relevant findings from radiobiology, emphasizing 3 points. First, the CML models almost all assert that the latency time, from CML initiation to diagnosis, is at most ∼10 years.
View Article and Find Full Text PDFChaos
December 2011
Neuroscience Program, Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701, USA.
Coherence and information theoretic analyses were applied to quantitate the response properties and the encoding of time-varying stimuli in paddlefish electroreceptors (ERs), studied in vivo. External electrical stimuli were Gaussian noise waveforms of varied frequency band and strength, including naturalistic waveforms derived from zooplankton prey. Our coherence analyses elucidated the role of internal oscillations and transduction processes in shaping the 0.
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