Adaptive hysteresis compensation of piezoelectric actuator using direct inverse modelling approach

2018 ◽  
Vol 13 (2) ◽  
pp. 180-183 ◽  
Author(s):  
Yanding Qin ◽  
Rurui Jia
Keyword(s):  
Piezoelectric Actuator ◽  
Inverse Modelling ◽  
Hysteresis Compensation ◽  
Modelling Approach

Estimating local CH4 emissions in the Upper Silesian Coal Basin using inverse modelling

2021 ◽  
Author(s):  
Sebastian Wolff ◽  
Friedemann Reum ◽  
Christoph Kiemle ◽  
Gerhard Ehret ◽  
Mathieu Quatrevalet ◽  
...  
Keyword(s):  
Remote Sensing ◽  
A Priori ◽  
Point Sources ◽  
Airborne Lidar ◽  
Inverse Modelling ◽  
Emission Rates ◽  
Coal Basin ◽  
Upper Silesian Coal Basin ◽  
The Individual ◽  
Modelling Approach

<p>Methane (CH<sub>4</sub>) is the second most important anthropogenic greenhouse gas (GHG) with respect to radiative forcing. Since pre-industrial times, the globally averaged CH<sub>4</sub> concentration in the atmosphere has risen by a factor of 2.5. A large fraction of global anthropogenic CH<sub>4</sub> emissions originates from localized point sources, e.g. coal mine ventilation shafts. International treaties foresee GHG emission reductions, entailing independent monitoring and verification support capacities. Considering the spatially widespread distribution of point sources, remote sensing approaches are favourable, in order to enable rapid survey of larger areas. In this respect, active remote sensing by airborne lidar is promising, such as provided by the integrated-path differential-absorption lidar CHARM-F operated by DLR. Installed onboard the German research aircraft HALO, CHARM-F serves as a demonstrator for future satellite missions, e.g. MERLIN. CHARM-F simultaneously measures weighted vertical column mixing ratios of CO<sub>2</sub> and CH<sub>4</sub> below the aircraft. In spring 2018, during the CoMet field campaign, measurements were taken in the Upper Silesian Coal Basin (USCB) in Poland. The USCB is considered to be a European hotspot of CH<sub>4</sub> emissions, covering an area of approximately 50 km × 50 km. Due to the high number of coal mines and density of ventilation shafts in the USCB, individual CH<sub>4</sub> exhaust plumes can overlap. This makes simple approaches to determine the emission rates of single shafts, i.e. the cross-sectional flux method, difficult. Therefore, we use an inverse modelling approach to obtain an estimate of the individual emission rates. Specifically, we employ the Weather Research and Forecast Model (WRF) coupled to the CarbonTracker Data Assimilation Shell (CTDAS), an Ensemble Kalman Filter. CTDAS-WRF propagates an ensemble realization of the a priori CH<sub>4</sub> emissions forward in space and time, samples the simulated CH<sub>4</sub> concentrations along the measurement’s flight path, and scales the a priori emission rates to optimally fit the measured values, while remaining tied to the prior. Hereby, we obtain a regularized a posteriori best emission estimate for the individual ventilation shafts. Here, we report on the results of this inverse modelling approach, including individual and aggregated emission estimates, their uncertainties, and to which extent the data are able to constrain individual emitters independently.</p>

Using an inverse modelling approach with equifinality control to investigate the dominant controls on snowmelt nutrient export

2019 ◽  
Vol 33 (23) ◽  
pp. 2958-2977 ◽  
Author(s):  
Diogo Costa ◽  
John Pomeroy ◽  
Helen Baulch ◽  
Jane Elliott ◽  
Howard Wheater
Keyword(s):  
Inverse Modelling ◽  
Nutrient Export ◽  
Modelling Approach

An inverse modelling approach for estimating vehicular emissions in urban coastal areas of the Messina Strait

2012 ◽  
Vol 50 (1/2/3/4) ◽  
pp. 274 ◽  
Author(s):  
Antonio Cantelli ◽  
Giovanni Leuzzi ◽  
Paolo Monti ◽  
Paolo Viotti
Keyword(s):  
Coastal Areas ◽  
Inverse Modelling ◽  
Vehicular Emissions ◽  
Messina Strait ◽  
Modelling Approach
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