A Performance Measure for Evaluating Aircraft Landing Trajectories
A general performance index is developed for evaluating aircraft landing trajectories. The primary term in the index is the effect of noise on people residing near the air terminal. Other terms included are passenger comfort, fuel consumed, and the time spent in the near-terminal area. Models are developed for aircraft engine noise, passenger comfort, the population distribution about a specific airport, and the aircraft flight behavior. While this performance index may be used in computing optimal trajectories, it is also useful for comparing nonoptimal trajectories which, for one reason or another, may be worthy of consideration. Some examples of such comparisons are included through simulations of landing. The aircraft considered is a Boeing 737.
An Aircraft Noise Pollution Model for Tra jectory Optimization
The mobility of our society makes effective and efficient operation of our air terminals a necessity. For this reason, landing trajectories must be optimized. One important factor in the performance index is aircraft noise received by people residing near the terminal. This paper develops a mathematical model of this noise effect so that it may be included in the performance index. The model yields the boundary on the ground inside of which the noise level is at or above 70 dB. This area can be weighted with the population density. The model compares very favorably with available data.
New approach to vision-based BGA package inspection
Ball grid array (BGA) techniques have developed very fast due to the advantages of more I/O ports, small size, and so on. In this paper, a vision-based algorithm for BGA package inspection is proposed to accurately estimate center and diameters of solder-balls of BGA packages, so that defects of BGA packages, such as missing or extra balls, oversize or undersize balls, over-height or under-height balls, and pitch can be detected for ensuring the quality of BGA packages.