Explicit formulas for the state coordinates in nonlinear MIMO realization problem on homogeneous time scales

2012 ◽  
Author(s):  
Juri Belikov ◽  
Ulle Kotta ◽  
Maris Tonso
Keyword(s):  
Time Scales ◽  
The State ◽  
Explicit Formulas ◽  
Realization Problem

Rate modulation in dams and ruin problems

1996 ◽  
Vol 33 (2) ◽  
pp. 523-535 ◽  
Author(s):  
Søren Asmussen ◽  
Offer Kella
Keyword(s):  
State Space ◽  
Release Rate ◽  
Risk Process ◽  
The State ◽  
Limiting Distribution ◽  
Process Conditions ◽  
Explicit Formulas ◽  
Rate Modulation ◽  
Finite State ◽  
Finite State Space

We consider a dam in which the release rate depends both on the state and some modulating process. Conditions for the existence of a limiting distribution are established in terms of an associated risk process. The case where the release rate is a product of the state and the modulating process is given special attention, and in particular explicit formulas are obtained for a finite state space Markov modulation.

scholarly journals Computation of positive realization of MIMO hybrid linear systems in the form of second Fornasini-Marchesini model

2010 ◽  
Vol 20 (3) ◽  
pp. 267-285 ◽  
Author(s):  
Tadeusz Kaczorek ◽  
Łukasz Sajewski
Keyword(s):  
Linear Systems ◽  
Hybrid Systems ◽  
Transfer Matrix ◽  
Sufficient Conditions ◽  
The State ◽  
Realization Problem ◽  
Numerical Example ◽  
State Variable

Computation of positive realization of MIMO hybrid linear systems in the form of second Fornasini-Marchesini modelThe realization problem for positive multi-input and multi-output (MIMO) linear hybrid systems with the form of second Fornasini-Marchesini model is formulated and a method based on the state variable diagram for finding a positive realization of a given proper transfer matrix is proposed. Sufficient conditions for the existence of the positive realization of a given proper transfer matrix are established. A procedure for computation of a positive realization is proposed and illustrated by a numerical example.

scholarly journals Accuracy of Potential Evapotranspiration Models in Different Time Scales

2020 ◽  
Vol 35 (1) ◽  
pp. 63-80
Author(s):  
Lucas Eduardo de Oliveira Aparecido ◽  
Kamila Cunha de Meneses ◽  
Guilherme Botega Torsoni ◽  
José Reinaldo da Silva Cabral de Moraes ◽  
Daniel Zimmermann Mesquita
Keyword(s):  
Time Scales ◽  
Potential Evapotranspiration ◽  
The State ◽  
Estimation Methods ◽  
Irrigated Agriculture ◽  
Mato Grosso ◽  
Daily Scale ◽  
Mato Grosso Do Sul ◽  
Different Time Scales ◽  
Estimation Models

Abstract Know the precision of potential evapotranspiration models in different agronomic and climatic conditions is useful for irrigated agriculture. Therefore, we aimed to compare 18 methods of estimation of ETP with the Penman-Monteith (FAO-56) method, at different time scales for the State of Mato Grosso do Sul. Time series of climatic data were used on a daily scale between 1983 and 2018 from 22 locations in the state of Mato Grosso do Sul. ETP estimation models tested were: Benevidez-Lopez, Blaney-Criddle, Camargo, Hamon, Hargreaves, Hargreaves-Samani, Jensen-Haise, Jobson, Kharrufa, Linacre, Makkink, Penman, Priestley-Taylor, Radiation, Romanenko, Tanner-Pelton, Thornthwaite, and Turc. These models were compared with Penman-Monteith in daily, weekly, and monthly scales. The comparison between the ETP estimation models and the Penman-Monteith model was performed by the statistical indices: accuracy (MAPE) and precision (R2aj). Estimation methods showed differences in efficiency over time scales. The best performances of the models were on the daily scale. For daily scale, methods of Priestley-Taylor, Hargreaves, Hamon, and Makkink present the best values of accuracy and precision for the State of Mato Grosso do Sul. In the weekly scale, the most accurate methods are Hamon and Makkink, while for monthly scale the best methods are Makkink and Priestley-Taylor.

scholarly journals Re-Examining Factors That Affect Delta Smelt (Hypomesus transpacificus) Entrainment at the State Water Project and Central Valley Project in the Sacramento–San Joaquin Delta

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Lenny Grimaldo ◽  
William Smith ◽  
Matthew Nobriga
Keyword(s):  
Time Scales ◽  
Central Valley ◽  
The State ◽  
First Flush ◽  
Bypass Flow ◽  
Yolo Bypass ◽  
Delta Smelt ◽  
Water Project ◽  
State Water ◽  
Hypomesus Transpacificus

Managing endangered species is challenging when increased rarity leads to an inability to detect their responses to environmental conditions. In the San Francisco Estuary, the state and federally listed Delta Smelt (Hypomesus transpacificus) has declined to record low numbers, elevating concern over entrainment at the State Water Project (SWP) and Central Valley Project (CVP) water export facilities. The objective of this study was to: (1) revisit previous work on factors that affect adult Delta Smelt collected at the SWP and CVP fish collection facilities using updated conceptual models and a new statistical approach; and (2) to determine factors that affect salvage at time-scales of interest to management. Boosted Regression Tree (BRT) models were applied to salvage data at the SWP and CVP, aggregated into two response categories: a “first flush” response that represented daily salvage from the start of the entrainment window to the 50% midpoint of observed salvage, and a “seasonal” response that included daily salvage from the entire entrainment window. Precipitation, sub-adult abundance, Yolo Bypass flow, and exports best explained first flush salvage at both the SWP and CVP. The seasonal models included a similar set of influential variables, but the relative influence of precipitation was lower compared to the first flush models., Yolo Bypass flow was more influential for seasonal salvage at the SWP, compared to the CVP; Old and Middle River flow was more influential for seasonal salvage at the CVP. Although the rank of variable importance that explains salvage differed slightly between first flush and seasonal time-scales, this study suggests that salvage is most influenced by hydrodynamics, water quality, and population abundance. The application of BRT models to predict salvage is limited, because salvage has been low since federal protections were implemented in 2008. Forecast models that integrate real-time variables with fish behavior models may improve Delta Smelt management.

scholarly journals Re-Examining Factors that Affect Delta Smelt (Hypomesus transpacificus) Entrainment at the State Water Project and Central Valley Project in the Sacramento–San Joaquin Delta

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Lenny Grimaldo ◽  
William Smith ◽  
Matthew Nobriga
Keyword(s):  
Time Scales ◽  
Central Valley ◽  
The State ◽  
First Flush ◽  
Bypass Flow ◽  
Yolo Bypass ◽  
Delta Smelt ◽  
Water Project ◽  
State Water ◽  
Hypomesus Transpacificus

Managing endangered species is challenging when increased rarity leads to an inability to detect their responses to environmental conditions. In the San Francisco Estuary, the state and federally listed Delta Smelt (Hypomesus transpacificus) has declined to record low numbers, elevating concern over entrainment at the State Water Project (SWP) and Central Valley Project (CVP) water export facilities. The objective of this study was to: (1) revisit previous work on factors that affect adult Delta Smelt collected at the SWP and CVP fish collection facilities using updated conceptual models and a new statistical approach; and (2) to determine factors that affect salvage at time-scales of interest to management. Boosted Regression Tree (BRT) models were applied to salvage data at the SWP and CVP, aggregated into two response categories: a “first flush” response that represented daily salvage from the start of the entrainment window to the 50% midpoint of observed salvage, and a “seasonal” response that included daily salvage from the entire entrainment window. Precipitation, sub-adult abundance, Yolo Bypass flow, and exports best explained first flush salvage at both the SWP and CVP. The seasonal models included a similar set of influential variables, but the relative influence of precipitation was lower compared to the first flush models., Yolo Bypass flow was more influential for seasonal salvage at the SWP, compared to the CVP; Old and Middle River flow was more influential for seasonal salvage at the CVP. Although the rank of variable importance that explains salvage differed slightly between first flush and seasonal time-scales, this study suggests that salvage is most influenced by hydrodynamics, water quality, and population abundance. The application of BRT models to predict salvage is limited, because salvage has been low since federal protections were implemented in 2008. Forecast models that integrate real-time variables with fish behavior models may improve Delta Smelt management.

scholarly journals 100 Years of Progress in Understanding the Dynamics of Coupled Atmosphere–Ocean Variability

2019 ◽  
Vol 59 ◽  
pp. 8.1-8.57 ◽  
Author(s):  
David S. Battisti ◽  
Daniel J. Vimont ◽  
Benjamin P. Kirtman
Keyword(s):  
Time Scales ◽  
North Atlantic ◽  
The State ◽  
Meridional Overturning Circulation ◽  
In Situ Observation ◽  
Turbulent Heat ◽  
The North ◽  
The Pacific ◽  
Turbulent Heat Exchange ◽  
The North Atlantic

Abstract In situ observation networks and reanalyses products of the state of the atmosphere and upper ocean show well-defined, large-scale patterns of coupled climate variability on time scales ranging from seasons to several decades. We summarize these phenomena and their physics, which have been revealed by analysis of observations, by experimentation with uncoupled and coupled atmosphere and ocean models with a hierarchy of complexity, and by theoretical developments. We start with a discussion of the seasonal cycle in the equatorial tropical Pacific and Atlantic Oceans, which are clearly affected by coupling between the atmosphere and the ocean. We then discuss the tropical phenomena that only exist because of the coupling between the atmosphere and the ocean: the Pacific and Atlantic meridional modes, the El Niño–Southern Oscillation (ENSO) in the Pacific, and a phenomenon analogous to ENSO in the Atlantic. For ENSO, we further discuss the sources of irregularity and asymmetry between warm and cold phases of ENSO, and the response of ENSO to forcing. Fundamental to variability on all time scales in the midlatitudes of the Northern Hemisphere are preferred patterns of uncoupled atmospheric variability that exist independent of any changes in the state of the ocean, land, or distribution of sea ice. These patterns include the North Atlantic Oscillation (NAO), the North Pacific Oscillation (NPO), and the Pacific–North American (PNA) pattern; they are most active in wintertime, with a temporal spectrum that is nearly white. Stochastic variability in the NPO, PNA, and NAO force the ocean on days to interannual times scales by way of turbulent heat exchange and Ekman transport, and on decadal and longer time scales by way of wind stress forcing. The PNA is partially responsible for the Pacific decadal oscillation; the NAO is responsible for an analogous phenomenon in the North Atlantic subpolar gyre. In models, stochastic forcing by the NAO also gives rise to variability in the strength of the Atlantic meridional overturning circulation (AMOC) that is partially responsible for multidecadal anomalies in the North Atlantic climate known as the Atlantic multidecadal oscillation (AMO); observations do not yet exist to adequately determine the physics of the AMO. We review the progress that has been made in the past 50 years in understanding each of these phenomena and the implications for short-term (seasonal-to-interannual) climate forecasts. We end with a brief discussion of advances of things that are on the horizon, under the rug, and over the rainbow.

scholarly journals Volume of the space of qubit-qubit channels and state transformations under random quantum channels

2018 ◽  
Vol 30 (10) ◽  
pp. 1850019 ◽  
Author(s):  
Attila Lovas ◽  
Attila Andai
Keyword(s):  
Lebesgue Measure ◽  
Quantum Channel ◽  
Probability Distributions ◽  
Building Blocks ◽  
The State ◽  
Quantum States ◽  
Qubit State ◽  
Quantum Channels ◽  
State Transformation ◽  
Explicit Formulas

The simplest building blocks for quantum computations are the qubit-qubit quantum channels. In this paper, we analyze the structure of these channels via their Choi representation. The restriction of a quantum channel to the space of classical states (i.e. probability distributions) is called the underlying classical channel. The structure of quantum channels over a fixed classical channel is studied, the volume of the general and unital qubit channels with respect to the Lebesgue measure is computed and explicit formulas are presented for the distribution of the volume of quantum channels over given classical channels. We study the state transformation under uniformly random quantum channels. If one applies a uniformly random quantum channel (general or unital) to a given qubit state, the distribution of the resulted quantum states is presented.

scholarly journals ON THE EVOLUTION OF AN ENTANGLED LEPTON–NEUTRINO PAIR

2011 ◽  
Vol 26 (02) ◽  
pp. 101-107 ◽  
Author(s):  
B. MESZÉNA ◽  
A. PATKÓS
Keyword(s):  
Wave Packet ◽  
Production Process ◽  
Time Scales ◽  
Charged Pion ◽  
Muon Neutrino ◽  
Pion Decay ◽  
Additional Time ◽  
Explicit Formulas ◽  
Type Wave ◽  
Neutrino Pair

The evolution of the entangled muon–neutrino system emerging from charged pion decay is explored both in vacuum and in matter. The study is based on a Weisskopf–Wigner type wave-packet description. Explicit formulas are derived displaying modulation and attenuation of the oscillations due to additional time scales characterizing the production process. The case of neutrinos disentangled due to the detection of the muon is also considered.

scholarly journals Estimation of the Tropical Pacific Ocean State 2010–13

2017 ◽  
Vol 34 (7) ◽  
pp. 1501-1517 ◽  
Author(s):  
Ariane Verdy ◽  
Bruce Cornuelle ◽  
Matthew R. Mazloff ◽  
Daniel L. Rudnick
Keyword(s):  
Pacific Ocean ◽  
Boundary Conditions ◽  
Time Scales ◽  
Tropical Pacific ◽  
The State ◽  
Tropical Pacific Ocean ◽  
Atmospheric Forcing ◽  
State Estimate ◽  
Independent Observations ◽  
The Tropical Pacific

AbstractA data-assimilating ⅓° regional dynamical ocean model is evaluated on its ability to synthesize components of the Tropical Pacific Ocean Observing System. The four-dimensional variational data assimilation (4DVAR) method adjusts initial conditions and atmospheric forcing for overlapping 4-month model runs, or hindcasts, that are then combined to give an ocean state estimate for the period 2010–13. Consistency within uncertainty with satellite SSH and Argo profiles is achieved. Comparison to independent observations from Tropical Atmosphere Ocean (TAO) moorings shows that for time scales shorter than 100 days, the state estimate improves estimates of TAO temperature relative to an optimally interpolated Argo product. The improvement is greater at time scales shorter than 20 days, although unpredicted variability in the TAO temperatures implies that TAO observations provide significant information in that band. Larger discrepancies between the state estimate and independent observations from Spray gliders deployed near the Galápagos, Palau, and Solomon Islands are attributed to insufficient model resolution to capture the dynamics in strong current regions and near coasts. The sea surface height forecast skill of the model is assessed. Model forecasts using climatological forcing and boundary conditions are more skillful than climatology out to 50 days compared to persistence, which is a more skillful forecast than climatology out to approximately 20 days. Hindcasts using reanalysis products for atmospheric forcing and open boundary conditions are more skillful than climatology for approximately 120 days or longer, with the exact time scale depending on the accuracy of the state estimate used for initializing and on the reanalysis forcing. Estimating the model representational error is a goal of these experiments.

Sign in / Sign up

Export Citation Format

Share Document