general extreme value
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Author(s):  
C. Huang ◽  
Yong-Chang Huang

This paper discovers that current canonical variational principle and canonical Noether theorem of (in)finite freedom systems for different physics systems have neglected doublet extreme value processes of the general extreme value functional that both is derived by variational principle and is necessarily be taken in deriving all ( quantum ) physics laws in phase space, but which have not been done for over one century since Noether's showing her distinguished theorem, which lead to the crisis deriving all (quantum) physics laws (necessary) in phase space. We discover there is the hidden logic cycle that people assume canonical equations, and then they finally deduce canonical equations by the equivalent relation in the whole processes in all current references. We correct the current key mistake concepts that when physics systems take the variational extreme values, the appearing processes of the physics systems are real physics processes, otherwise, are virtual processes in all current references. The real physics should be what after taking the physics systems' variational extreme values, the physics systems' general extremum functional needs to further take the general extremum functional's minimum absolute extremum zero, otherwise, the appearing processes of physics systems still are virtual processes. Conservation current equations and conservation currents, in phase space, of general canonical variational principle and general canonical Noether theorem are, respectively, deduced for the first time. Using the general extremum functionals' doublet extreme value processes, the hidden logic cycle and the crisis in current canonical variational principle and current canonical Noether theorem are solved. Consequently, the new mathematical pictures, classical and quantum new physics in phase space and the new mathematical and physical doublet extremum processes for (in)finite freedom systems are discovered. General canonical variational principle and general canonical Noether theorem naturally are given, which would rewrite all the different sciences in phase space, as key tools of studying and dealing with them.


2020 ◽  
Vol 30 (4) ◽  
pp. 18
Author(s):  
Meeran Akram Fawzee ◽  
Samira M. Salh ◽  
Slahaddin A. Ahmed

Study the statistical distribution for rainfall is important to know the behaviour of the rainfall series and to know the most frequently rainfall amount in each month. Five statistical distribution were applied on Sulaimani, Erbil and Duhok rainfall series for the period (1941-2017) except Duhok (1944-2017). These distributions were Gamma(3P), Weibul(3P), Earlang (3P), Normal and General extreme value. Kolmogrove-Semirnov, Anderson-Darling and Chi-Square goodness of fit test were used to know the best fit distribution from these five distributions.


Author(s):  
Dang Kien Cuong ◽  
Duong Ton Dam ◽  
Duong Ton Thai Duong ◽  
Ngo Thuan Du

2015 ◽  
Vol 17 (3) ◽  
pp. 525-535

<div> <p>The Hydrologic Simulation Program-FORTRAN (HSPF) model is widely used to develop management strategies for water resources and to evaluate the hydrologic effect of various management scenarios. The spatial resolution of the input data used to parameterize HSPF model may induce uncertainty in model outputs. In this study, the impact of spatial resolutions of Digital Elevation Model (DEM) and land use map on the uncertainty of HSPF predicted flow and sediment were evaluated. DEM resolution can affect stream length, watershed area and average slope, whereas land use data resolution can lead to redistribution of land use information. Results showed that finer resolution DEM and land use maps can generate higher flow volumes and sediment loads compared to modelling scenarios using inputs of coarse resolution. The relative change in model performance between the baseline scenario (high-resolution) and scenarios of coarser resolution described uncertainties due to DEM and land use spatial information, and the probability density function of these uncertainties was used to estimate these uncertainties. Modelled flow and sediment uncertainty due to DEM resolution seems to follow a log-normal and a general extreme value distribution respectively, whereas modelled flow and sediment uncertainty due to land use resolution seems to both follow a general extreme value distribution. Overall, results highlight the need for a high-resolution DEM and land use maps in the application of the HSPF model while they provide useful information for reducing the model uncertainties.</p> </div> <p>&nbsp;</p>


2014 ◽  
Vol 27 (3) ◽  
pp. 189-203 ◽  
Author(s):  
Karima Benhattab ◽  
Christophe Bouvier ◽  
Mohamed Meddi

L’estimation locale des pluies extrêmes et de leur période de retour est souvent peu précise du fait de données peu nombreuses. Le regroupement de données d’une même région permet souvent d’améliorer la précision de cette estimation. Cet article propose une approche régionale pour l’estimation des pluies journalières de fréquence rare, pour le bassin hydrographique du Cheliff (nord-ouest de l´Algérie). La première étape consiste à définir et à valider les régions homogènes de la zone d’étude. Le test d'homogénéité est basé sur la statistique H, qui compare les rapports des L-moments calculés localement à chaque station à leur moyenne sur la région considérée. La deuxième étape consiste à identifier la distribution régionale et à estimer ses paramètres par analyse du diagramme des L-moments et/ou calcul de la statistique Zdist, qui compare les rapports des L-moments régionaux à ceux de la distribution candidate. La loi GEV (« General Extreme Value »), qui a été utilisée dans plusieurs études antérieures de régionalisation des précipitations extrêmes, a été identifiée comme distribution régionale adéquate. Les paramètres de la GEV ont été calculés à l’aide de la définition des L-CV, L-CS et L-CK régionaux. La troisième étape consiste à déterminer localement les quantiles de pluie associés aux différentes périodes de retour, par multiplication du L-coefficient de variation régionale L-CV par la moyenne des précipitations journalières maximales annuelles observées au site considéré. Les pluies calculées par cette méthode, qui peut être appliquée à toute station de la zone étudiée, peuvent être significativement différentes de celles calculées par ajustement local. Les valeurs de l’erreur quadratique moyenne entre les quantiles calculés par approche régionale ou locale sont égales à 10 % pour la pluie journalière maximale annuelle décennale, et à 35 % pour la pluie journalière maximale annuelle centennale. Cette erreur diminue quand la longueur de la série locale augmente, ce qui suggère que l’approche régionale consolide effectivement l’estimation des quantiles de pluie.


2011 ◽  
Vol 55 (3) ◽  
pp. 1379-1393 ◽  
Author(s):  
Wagner Barreto-Souza ◽  
Klaus L.P. Vasconcellos

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