where τ, δ, a, b, c, r, k ∈ C(R, (0,∞)) are ω-periodic functions. The assumption of periodicity of the parameters a(t), b(t), c(t), k(t), r(t) is a way of incorporating the periodicity of the environment (e.g. seasonal effects of weather condition, food supplies, temperature, etc.). The main purpose of this paper is to establish the existence of a positive periodic solution of system (2), using...

We report on the retrieval of directional sea surface roughness, in terms of its full directional mean square slope (including direction and isotropy), from Global Navigation Satellite System Reflections (GNSS-R) Delay-Doppler-Map (DDM) data collected during an experimental flight at 1 km altitude. This study emphasizes the utilization of the entire DDM to more precisely infer ocean roughness d...

HUB SIAASHING is a knowledge-based system that recommends contingency plans for American Airlines System Operations Control (SOC) during inclement weather or other airport disruptions where severe schedule reductions must be made. The system evaluates the current situation to determine flight cancellation, delay, and overfly candidates that will provide relief at the hub airport with minimal im...

A feed-forward, supervised, multi-layer perceptron Artificial Neural Network (ANN) was developed to test the following hypothesis: An ANN can be developed to successfully forecast thunderstorm activity up to 24 hours in advance, and with a spatial accuracy of 20-km, wherein ANN inputs include selected output from (1) deterministic mesoscale Numerical Weather Prediction (NWP) models, and from (2...

background: the purpose of this study was to compare patient delay, diagnosis delay and treatment delay in breast cancer patients of selected public and private health centers in tehran, iran. methods: in this cross-sectional study, female patients with newly diagnosed breast cancer in a public medical complex and a private breast clinic within one year were included. patient delay was consider...

This paper presents a linear Integer Programming model for managing air traffic flow in the United States. The decision variables in the model are departure delays and predeparture reroutes of aircraft whose trajectories are predicted to cross weather-impacted regions of the National Airspace System. The model assigns delays to a set of flights while ensuring their trajectories are free of any ...

The atmospheric environment is one of the critical factors affecting troposcatter transmission loss and propagation delay. This article proposes a new estimation model that can accurately calculate delay with numerical weather (NWM). ERA5 reanalysis data as NWM are applied to construct model. 3-D ray-tracing beam splitting used paths delays. Compared existing methods, thoroughly considered bend...

In order to obtain high data rate T.V. picture transmissions from spacecrafts on planetary missions consideration has been given in the past to the use of laser com­ munications systems. If no relay satellite is used a deep space laser communication link would involve propagation through the earths atmosphere to a ground based station. This paper gives consideration to the characteristic of the...

*It is very important to accurately characterize the three-dimensional distribution of water vapor in the atmosphere for the understanding and prediction of mesoscale and storm-scale weather, especially with regard to quantitative precipitation forecasting (Emanuel et al. 1995). Skills in these predictions have been improved rather slowly owing to the high spatial and temporal variability of wa...