Modeling next generation air traffic control system with petri net

The Federal Aviation Administration (FAA) is one of the largest Air Navigation Service Providers, managing air traffic for more than 15% of the world\u27s airspace. Today\u27s Air Traffic Control (ATC) system cannot meet the growth of the air traffic activities, which brings with more unprecedented delays. At the same time, Air Traffic Controllers are facing higher workload than ever before. The FAA has declared that the existing ATC system will transition to a new system known as “Free Flight”. “Free Flight” will change today\u27s ATC system by giving pilots increased flexibility to choose and modify their routes in real time, thereby reducing cost and increasing system capacity (Nordwall, 1995). In this work, the modules and data flow of the next generation ATC system is designed, and their Petri net models are constructed for the control module to achieve “Free Flight”

Correlation between Health and Stress

This study examined participants’ level of stress and their perceived level of stress and success in school. The subjects were given the stress questionnaire in order to determine the level of stress they were experiencing and the frequency of health issues experienced during the previous year. The results of the study suggest that although level of stress may be similar between individuals, how they perceived the stress impacted their health level. Students who perceived the stress in a negative fashion were more likely to be sick than individuals who were less impacted by the stress. By identifying the correlation between health and stress, the study aimed to suggesting ways to minimize the negative impacts of stress to students

Possible Psychological Effects of Ultrasound Scanning on Women

Questionnaires were designed and given to 30 female subjects to investigate the possible psychological effects caused by the use of ultrasound scanning. The answers were analyzed in a numerical way and correlation tests were run to explore the relations among various factors. No significant correlation was found between any pair of the four selected factors. Further interviews with the subjects and detailed qualitative study of the answers provided answers for the results, and suggested that the possible psychological effects introduced by the ultrasound scanning, if any, were very limited

Study of Balance Equations for Hot-Electron Transport in an Arbitrary Energy Band (III)

By choosing an electron gas resting instead of drifting in the laboratory coordinate system as the initial state, the first order perturbation calculation of the previous paper (Phys. Stat. Sol. (b) 198, 785(1996)) is revised and extended to include the high order field corrections in the expression for the frictional forces and the energy transfer rates. The final expressions are formally the same as those in first order in the electric field, but the distribution functions of electrons appearing in them are defined by different expressions. The problems relative to the distribution function are discussed in detail and a new closed expression for the distribution function is obtained. The nonlinear impurity-limited resistance of a strong degenerate electron gas is computed numerically. The result calculated by using the new expression for the distribution function is quite different from that using the displaced Fermi function when the electric field is sufficiently high.Comment: 15 pages with 3 PS figures, RevTeX, to be published in Physica Status Solidi (b

A complex NLR signalling network mediates immunity to diverse plant pathogens

Both plants and animals rely on nucleotide-­binding domain leucine-­rich repeat-­containing (NLR) proteins to respond to invading pathogens and activate immune responses. An emerging concept in NLR biology is that “sensor” NLR proteins are often paired with “helper” NLR proteins to mediate immune signalling. However, the degree to which NLRs form signalling networks beyond sensor and helper pairs is poorly understood. In this thesis, I discovered that a large NLR immune signalling network with a complex architecture mediates immunity to oomycetes, bacteria, viruses, nematodes, and insects. Helper NLRs in the NRC (NLR-­required for cell death) family are functionally redundant but display distinct specificities towards diverse sensor NLRs. Several sensor NLRs, including Rx, Bs2 and Sw5b, signal via interchangeable NRC2, NRC3 or NRC4, whereas some other sensor NLRs have a more limited downstream spectrum. For example, Prf signals via interchangeable NRC2 or NRC3 but not NRC4, and Rpi-­blb2 signals via only NRC4. These helper/sensor NLRs form a unique phylogenetic superclade, with the NRC clade sister to the sensor NLR clades. The network has emerged over 100 million years ago from an NLR pair that diversified into up to one half of the NLRs of asterids. I propose that this NLR network increases evolvability and robustness of immune signalling to counteract rapidly evolving plant pathogens