Within the Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) there is a need for an assessment of the uncertainty in the integrated water vapour (IWV) in the atmosphere estimated from ground-based global navigation satellite system (GNSS) observations. All relevant error sources in GNSS-derived IWV are therefore essential to be investigated. We present two approaches, a...

introduction: pulmonary tuberculosis is major problem worldwide and it is estimated one third the world population are already infected and each year 9 million people develop full blown tuberculosis of these 3 million die of the disease, annually. delay in diagnosis and treatment are major problems that play a significant role in all aspect of the disease from patient treatment to transmission ...

In recent years, flight delay costs the air transportation industry millions of dollars and has become a systematic problem. Understanding behavior is thus critical. This paper focuses on how affected by operation-, time-, weather-related factors. Different econometric models are developed to analyze departure arrival delay. The results show that compared delay, more likely be previous delays b...

This paper presents an analysis of National Airspace System (NAS) delay. An interacting set of models called the Airspace Concept Evaluation System (ACES) was used to simulate one day of NAS-wide air traffic. A total of 36 simulations were run. They included nine different airport capacity conditions across the NAS and four levels of NAS-wide demand. The analysis of delay results for these 36 s...

We formulate and analyze a delay differential equation model for the transmission of West Nile virus between vector mosquitoes and avian hosts that incorporates maturation delay for mosquitoes. The maturation time from eggs to adult mosquitoes is sensitive to weather conditions, in particular the temperature, and the model allows us to investigate the impact of this maturation time on transmiss...

We report on the retrieval of directional sea-roughness (the full directional mean square slope, including direction and isotropy) through inversion of Global Navigation Satellite System Reflections (GNSS-R) data collected during an experimental flight at 1 km altitude. The emphasis is on the utilization of the entire Delay-Doppler Map (DDM) in order to infer ocean roughness directional paramet...

On any given day, constraints in the National Airspace System, for instance weather, necessitate the implementation of Traffic Flow Management initiatives, such as Ground Delay Programs. The parameters associated with these initiatives, for example the location, scope, duration, etc., are typically left to human decision makers, who must rely on intuition, past experience, and weather and traff...

The National Airspace System (NAS) is a large and complex system with thousands of interrelated components: administration, control centers, airports, airlines, aircraft, passengers, etc. The complexity of the NAS creates many difficulties in management and control. One of the most pressing problems is flight delay. Delay creates high cost to airlines, complaints from passengers, and difficulti...

Harsh winter climate can cause various problems for both public and private sectors in Sweden, especially the northern part railway industry. To have a better understanding of impacts, this study investigates effects including ice/snow precipitation on performance high speed passenger trains Botnia-Atlantica region. The investigation is done with train operational data together simulated weathe...