Given the sequence of phases and flight modes that represent the flight plan of a commercial aircraft, the initial and final states, and a set of path constraints, we solve the multi-phase optimal control problem of finding control inputs, switching times between flight modes and the corresponding trajectory of the aircraft that minimizes fuel consumption. The aircraft in flight is modeled as a...

The Enhanced Trajectory Prediction Model (ETPM) is a logical extension of our analytic performance calculation framework “Enhanced Jet Performance Model” (EJPM), [1]. The ETPM is now capable to predict 4D trajectories of commercial or military jet aircraft with significantly increased model accuracy compared to existing performance tools such as BADA [4]. The EJPM so allows track optimization w...

in this study, the stochastic cell formation problem with developing model within queuing theory with stochastic demand, processing time and reliability has been presented. machine as server and part as customer are assumed where servers should service to customers. since, the cell formation problem is np-hard, therefore, deterministic methods need a long time to solve this model. in this study...

this paper presents a new nonlinear mathematical model to solve a cell formation problem which assumes that processing time and inter-arrival time of parts are random variables. in this research, cells are defined as a queue system which will be optimized via queuing theory. in this queue system, each machine is assumed as a server and each part as a customer. the grouping of machines and parts...

Abstract: The exploration of Earth-like exoplanets will be enabled at mid-infrared wavelengths through technology and engineering advances in nulling interferometry and precision formation flying. Nulling interferometry provides the dynamic range needed for the detection of biomarkers. Formation flying provides the angular resolution required in the mid-infrared to separately distinguish the sp...

Using analyses of iliac crest cell and tissue, back-scattered electron imaging, and biochemical techniques, we characterized the effects of a 14-day spaceflight (Bion 11) on bone structure and bone formation in two 3- to 4-yr-old male rhesus monkeys compared with eight age-matched Earth-control monkeys. We found that postflight bone volume was 35% lower than preflight values in flight monkeys. ...

As part of an experiment to study the role of corticosteroids in bone changes during spaceflight, male Sprague-Dawley rats (6 wk old, 165 g body weight) were placed in orbit for 17 days, in groups of six, in animal-enclosure modules (AEMs) aboard the space shuttle Columbia (STS-78). Control rats were group housed in a similar manner in ground-based AEMs or standard vivarium cages. Adrenal hyper...

introduction: herpes labialis is important in dentistry because of its high prevalence. herpes simplex virus (hsv) is responsive to treatment and infection control methods help protect patients and dental personnel. due to high levels of stress in the flight crew this study evaluated the prevalence of recurrent herpes labialis in the personnel of an airline company. materials and methods: in th...

Due to the rapid growth of air transport traffic, how to efficiently allocate gates at airports to incoming or outgoing flights has become one of the most important problems which managers of airlines and airports have to concern about. The problem, which can be modeled as a scheduling problem, is often referred to as flight gate scheduling. The main purpose of flight gate scheduling is to find...