scholarly journals Model calibration using the automatic parameter estimation procedure (PEST) of the North-eastern zone of the Milan Functional Urban Area (Italy)

Author(s):  
Luca Alberti

La Functional Urban Area (FUA) di Milano è un’area densamente popolata (2.254.263 abitanti) dove l’approvvigionamento idrico è garantito esclusivamente mediante prelievi idrici sotterranei. Per questa ragione la protezione della qualità delle falde rientra tra le priorità delle politiche ambientali di Regione Lombardia. Recentemente è stato avviato un programma di studi ed interventi aventi lo scopo d’individuare i principali plumes di contaminazione da solventi clorurati distinguendone l’impatto da quello legato all’inquinamento diffuso. In questo articolo si presenta il modello di flusso sviluppato per il settore NE della FUA di Milano, settore utilizzato quale area pilota per sviluppare e testare una nuova metodologia che combina statistica e modellistica al fine di distinguere il contributo delle fonti di contaminazione puntuale rispetto a quelle diffuse.

Author(s):  
Galina Vasil’evna Troshina ◽  
Alexander Aleksandrovich Voevoda

It was suggested to use the system model working in real time for an iterative method of the parameter estimation. It gives the chance to select a suitable input signal, and also to carry out the setup of the object parameters. The object modeling for a case when the system isn't affected by the measurement noises, and also for a case when an object is under the gaussian noise was executed in the MatLab environment. The superposition of two meanders with different periods and single amplitude is used as an input signal. The model represents the three-layer structure in the MatLab environment. On the most upper layer there are units corresponding to the simulation of an input signal, directly the object, the unit of the noise simulation and the unit for the parameter estimation. The second and the third layers correspond to the simulation of the iterative method of the least squares. The diagrams of the input and the output signals in the absence of noise and in the presence of noise are shown. The results of parameter estimation of a static object are given. According to the results of modeling, the algorithm works well even in the presence of significant measurement noise. To verify the correctness of the work of an algorithm the auxiliary computations have been performed and the diagrams of the gain behavior amount which is used in the parameter estimation procedure have been constructed. The entry conditions which are necessary for the work of an iterative method of the least squares are specified. The understanding of this algorithm functioning principles is a basis for its subsequent use for the parameter estimation of the multi-channel dynamic objects.


Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 343 ◽  
Author(s):  
Gabriela Dudek ◽  
Przemysław Borys

A procedure to estimate the diffusion coefficient in solution–diffusion models of hydrophilic membranes used in pervaporation-based purification experiments is presented. The model is based on a series solution of the general permeation problem. It considers a membrane that can be filled with water or with the feed solution before the measurement. Furthermore, the length of the tubing between the permeation cell and the place of cold traps is also addressed. To illustrate the parameter estimation procedure, we have chosen the data for the separation of water and ethanol by chitosan membranes. It is shown that the diffusion coefficient can be estimated effectively from the time course of the transported mass and by the analysis of certain well defined time lags of the permeation curve.


2020 ◽  
Vol 55 ◽  
pp. 9-38
Author(s):  
Jacek Andrzejowski

In phase B1, and very prominently – in phase B2 of the Roman Period, tribal groups of the north-eastern territories of the Przeworsk culture displayed a number of characteristic regional elements. These elements are mostly seen in female outfits that become much richer and more varied than elsewhere within the Przeworsk culture territory. The features specific for the Eastern Przeworsk Zone, like e.g., a very high frequency of dress elements made of copper alloys, would be largely the effect of mutual relations of these people with communities of the Wielbark culture from Eastern Pomerania. Though outwardly only ethnographic, this specificity of the material culture may have deeper underlying causes, since starting with phase B1, there is evidence of two basic types of Eastern Przeworsk cemeteries. In both cases, the women’s grave furnishings display general Eastern Przeworsk characteristics. In cemeteries of the first group weapon graves disappear already in early phase B1. These cemeteries fell out of use before the end of phase B2 and reflect the full, or nearly full withdrawal of the ‘Przeworsk’ community from that area. The second group form Przeworsk cemeteries with ‘standard’ weapon graves. From phase B2/C1 on, the Wielbark culture newcomers continued to use many of these cemeteries. Many of them were then continuously used from phase B2/C1 by the Wielbark culture newcomers. It appears that a part of the Przeworsk population from the Eastern Zone probably joined Gothic (Wielbark) tribes then moving south. Recently many brooches recognized traditionally as definitely ethnographic markers of the Przeworsk culture (types Almgren 43 and Almgren 129) have been registered in the western provinces of nowadays Ukraine. However, these finds are already much more numerous than those from the ‘core’ territory of the Przeworsk culture – for the time being, this phenomenon seems to be inexplicable.


1994 ◽  
Vol 76 (3) ◽  
pp. 1378-1383 ◽  
Author(s):  
S. A. Slordahl ◽  
H. F. Kuecherer ◽  
J. E. Solbakken ◽  
H. Piene ◽  
B. A. Angelsen ◽  
...  

The regurgitant volume and regurgitant orifice area as well as total peripheral resistance and arterial compliance were estimated in a cardiovascular hydromechanical simulator and in 10 patients with aortic regurgitation. A parameter estimation procedure based on a simple model of the cardiovascular system, Doppler measurements of the regurgitant jet, aortic systolic flow, and systolic and diastolic blood pressures was used. In the cardiovascular simulator the estimated regurgitant orifice area was compared with the size of a hole in the disk of a mechanical aortic valve. In the patients the regurgitant fraction was compared with semiquantitative grading from echocardiography routinely performed in our laboratory. In the hydromechanical simulator, the estimated regurgitant orifice area of 26.5 +/- 3.5 (SD) mm2 (n = 9) was not different from the true value of 24 mm2. In the patients there was a fair relationship between the estimated regurgitant fraction and the semiquantitative grading. The estimated regurgitant orifice areas varied between 1.6 and 31.2 mm2. The estimated mean values of total peripheral resistance and arterial compliance were 1.67 +/- 0.55 mmHg.s.ml-1 and 1.30 +/- 0.42 ml/mmHg, respectively.


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