Dynamic stochastic model for refractive turbulence in wind shear for wind profile measurement

1993 ◽  
Author(s):  
Robert P. Leland
Keyword(s):  
Stochastic Model ◽  
Wind Shear ◽  
Wind Profile ◽  
Profile Measurement ◽  
Dynamic Stochastic

A stability analysis on a smoking model with stochastic perturbation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Anwar Zeb ◽  
Sunil Kumar ◽  
Almaz Tesfay ◽  
Anil Kumar
Keyword(s):  
Stochastic Model ◽  
Stochastic System ◽  
Existence And Uniqueness ◽  
Deterministic Model ◽  
Sufficient Conditions ◽  
Reproductive Number ◽  
Content Type ◽  
Model Form ◽  
The World ◽  
Dynamic Stochastic

Purpose The purpose of this paper is to investigate the effects of irregular unsettling on the smoking model in form of the stochastic model as in the deterministic model these effects are neglected for simplicity. Design/methodology/approach In this research, the authors investigate a stochastic smoking system in which the contact rate is perturbed by Lévy noise to control the trend of smoking. First, present the formulation of the stochastic model and study the dynamics of the deterministic model. Then the global positive solution of the stochastic system is discussed. Further, extinction and the persistence of the proposed system are presented on the base of the reproductive number. Findings The authors discuss the dynamics of the deterministic smoking model form and further present the existence and uniqueness of non-negative global solutions for the stochastic system. Some previous study’s mentioned in the Introduction can be improved with the help of obtaining results, graphically present in this manuscript. In this regard, the authors present the sufficient conditions for the extinction of smoking for reproductive number is less than 1. Research limitations/implications In this work, the authors investigated the dynamic stochastic smoking model with non-Gaussian noise. The authors discussed the dynamics of the deterministic smoking model form and further showed for the stochastic system the existence and uniqueness of the non-negative global solution. Some previous study’s mentioned in the Introduction can be improved with the help of obtained results, clearly shown graphically in this manuscript. In this regard, the authors presented the sufficient conditions for the extinction of smoking, if <1, which can help in the control of smoking. Motivated from this research soon, the authors will extent the results to propose new mathematical models for the smoking epidemic in the form of fractional stochastic modeling. Especially, will investigate the effective strategies for control smoking throughout the world. Originality/value This study is helpful in the control of smoking throughout the world.

Aircraft Behaviour in a Vertical Gradient of Wind Velocity

1963 ◽  
Vol 14 (3) ◽  
pp. 265-278 ◽  
Author(s):  
J. K. Zbrożek
Keyword(s):  
Theoretical Analysis ◽  
Wind Velocity ◽  
Wind Shear ◽  
Wind Profile ◽  
Numerical Study ◽  
Vertical Gradient ◽  
Jet Stream ◽  
Strong Wind ◽  
Aircraft Motion ◽  
The Stability

SummaryThe stability of the phugoid motion of an aircraft in the presence of wind shear is investigated. The effect of the wind shear on the phugoid frequency increases with increasing aircraft speed and can be stabilising or destabilising, depending on the aircraft orientation relative to the wind shear. The destabilising effect of wind shear is alleviated by the stabilising effect of the density gradient of the atmosphere. At the most critical combination of speed and altitude a strong wind shear may lead to divergence, with a time to double amplitude of the order of 10-15 seconds.A numerical study of the aircraft motion with controls fixed when descending through a wind profile similar to that in a jet stream indicates that the increase in the aircraft indicated speed can be of the same magnitude as, or larger than, the maximum wind velocity increment in the jet stream core. However, as the time to reach the excess speed is of the order of one minute, the actual behaviour of the aircraft strongly depends on the pilot's action and thus is not fully predictable by theoretical analysis.

scholarly journals Comparative Evaluation of Algorithms for Spatial Interpolation of Atmospheric State Parameters Based on a Dynamic Stochastic Model Taking into Account the Vertical Variation of a Meteorological Field

Symmetry ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1207
Author(s):  
Popov ◽  
Lavrinenko ◽  
Krasnenko ◽  
Popova ◽  
Popova ◽  
...  
Keyword(s):  
Stochastic Model ◽  
Spatial Interpolation ◽  
Forecast Model ◽  
Wind Fields ◽  
Vertical Variation ◽  
Meteorological Field ◽  
Dynamic Stochastic ◽  
Atmospheric State ◽  
Observation Space

The paper presents a comparative analysis of two algorithms for the spatial interpolation of meteorological fields. Both algorithms are based on a four-dimensional low-order parametric dynamic stochastic model, taking into account the vertical variation of a meteorological field. The algorithms are characterized by different representations of the forecast model in state and observation space equations for the Kalman filter. The authors studied the accuracy of the spatial interpolation of temperature and wind fields for the developed algorithms. The results of the study are presented in this paper. Numerical simulation was conducted using long-term upper-air observations obtained for a typical mesometeorological range. The results of the study demonstrate that the accuracy of interpolation for the two considered algorithms is comparable.

scholarly journals Analyzing Producer Preferences for Counter-Cyclical Government Payments

2003 ◽  
Vol 35 (3) ◽  
pp. 671-684 ◽  
Author(s):  
J. Corey Miller ◽  
Barry J. Barnett ◽  
Keith H. Coble
Keyword(s):  
Stochastic Model ◽  
Dynamic Stochastic ◽  
Representative Farms

A dynamic-stochastic model is developed to evaluate preferences among alternative countercyclical payment programs for representative farms producing corn or soybeans in Iowa and cotton or soybeans in Mississippi. Countercyclical payment programs are found to not necessarily be preferred to fixed payment programs.

scholarly journals A Multi-Year Evaluation of Doppler Lidar Wind-Profile Observations in the Arctic

2020 ◽  
Vol 12 (2) ◽  
pp. 323 ◽  
Author(s):  
Zen Mariani ◽  
Robert Crawford ◽  
Barbara Casati ◽  
François Lemay
Keyword(s):  
Wind Profile ◽  
Weather Prediction ◽  
Multiscale Model ◽  
Model Verification ◽  
The Arctic ◽  
High Temporal Resolution ◽  
Profile Measurement ◽  
Doppler Lidar ◽  
Average Bias ◽  
Nwp Model

Doppler light detection and ranging (lidar) wind profilers have proven their capability to measure vertical wind profiles with an accuracy comparable to anemometers and radiosondes. However, most of these comparisons were performed over short time periods or at mid-latitudes. This study presents a multi-year assessment of the accuracy of Doppler lidar wind-profile measurements in the Arctic by comparing them with coincident radiosonde observations, and excellent agreement was observed. The suitability of the Doppler lidar for verification case studies of operational numerical weather prediction (NWP) models during the World Meteorological Organization’s Year of Polar Prediction is also demonstrated, by using Environment and Climate Change Canada’s (ECCC) global environmental multiscale model (GEM-2.5 km and GEM-10 km). Since 2016, identical scanning Doppler lidars were deployed at two supersites commissioned by ECCC as part of the Canadian Arctic Weather Science project. The supersites are located in Iqaluit (64°N, 69°W) and Whitehorse (61°N, 135°W) with a third Halo Doppler lidar located in Squamish (50°N, 123°W). Two lidar wind-profile measurement methodologies were investigated; the velocity-azimuth display method exhibited a smaller average bias (−0.27 ± 0.02 m/s) than the Doppler beam-swinging method (–0.46 ± 0.02 m/s) compared to the sonde. Comparisons to ECCC’s NWP models indicate good agreement, more so during the summer months, with an average bias < 0.71 m/s for the higher-resolution (GEM-2.5 km) ECCC models at Iqaluit. Larger biases were found in the mountainous terrain of Whitehorse and Squamish, likely due to difficulties in the model’s ability to resolve the topography. This provides evidence in favor of using high temporal resolution lidar wind-profile measurements to complement radiosonde observations and for NWP model verification and process studies.

scholarly journals The dynamic stochastic model of a boiler unit

2021 ◽  
Vol 1889 (2) ◽  
pp. 022115
Author(s):  
N N Kutsy ◽  
A A Podkorytov
Keyword(s):  
Stochastic Model ◽  
Boiler Unit ◽  
Dynamic Stochastic
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