Publications

Multi-pitch estimation of co-channel speech is especially challenging when the underlying pitch tracks are close in pitch value (e.g., when pitch tracks cross). Building on our previous work, we demonstrate the utility of a two-dimensional (2-D) analysis method of speech for this problem by exploiting its joint representation of pitch...

Transcript-dependent speaker-recognition experiments are performed with the Mixer 1 and 2 read-transcription corpus using the Lincoln Laboratory speaker recognition system. Our analysis shows how widely speaker-recognition performance can vary on transcript-dependent data compared to conversational data of the same durations, given enrollment data from the same spontaneous conversational speech. A...

All large transport aircraft are required to be equipped with a collision avoidance system that instructs pilots how to maneuver to avoid collision with other aircraft. The uncertainty in the behavior of the intruding aircraft makes developing a robust collision avoidance logic challenging. This paper presents an automated approach for...

Rigorous scientific experimentation in system and network security remains an elusive goal. Recent work has outlined three basic requirements for experiments, namely that hypotheses must be falsifiable, experiments must be controllable, and experiments must be repeatable and reproducible. Despite their simplicity, these goals are difficult to achieve, especially when dealing...

This paper presents the results of a study to quantify the performance of Weather Avoidance Fields in predicting the operational impact of convective weather on en route airspace. The Convective Weather Avoidance Model identifies regions of convective weather that pilots are likely to avoid based upon an examination of the...

The paper describes an algorithm for constructing convective weather avoidance polygons. The algorithm combines weather avoidance fields (WAF) from the en route convective weather avoidance model (CWAM) with edges automatically detected in the echo tops field, clustering, convex hull fitting and wind data to build weather avoidance polygons. Results for...

This paper presents a benefits assessment methodology for an air traffic control tower advanced automation system called the Tower Flight Data Manager (TFDM), which is being considered for development by the FAA to support NextGen operations. The standard FAA benefits analysis methodology is described, together with how it has been...

Many aviation safety studies involve estimating near mid-air collision (NMAC) rate. In the past, it has been assumed that the probability that an NMAC leads to a mid-air collision is 0.1, but there has not yet been a comprehensive study to serve as a basis for this estimate. This paper...

Whenever machine learning is used to prevent illegal or unsanctioned activity and there is an economic incentive, adversaries will attempt to circumvent the protection provided. Constraints on how adversaries can manipulate training and test data for classifiers used to detect suspicious behavior make problems in this area tractable and interesting...

TCAS behavior in New England airspace is being monitored and analyzed, making use of an omni-directional 1030/1090 MHz receiver. The receiver system, located in Lexington, MA, and operated by M.I.T. Lincoln Laboratory, is used to record Resolution Advisories (RAs). Omni-directional receptions make it possible to examine the air-to-air messages exchanged...