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Bayesian discovery of threat networks

October 15, 2014
  |
Journal Article
Author:
Steven T. Smith
…
Published in:
IEEE Trans. Signal Process., Vol. 62, No. 20, 15 October 2014, pp. 5324-38.
Topic:
signal processing
R&D area:
R&D group:

Summary

A novel unified Bayesian framework for network detection is developed, under which a detection algorithm is derived based on random walks on graphs. The algorithm detects threat networks using partial observations of their activity, and is proved to be optimum in the Neyman-Pearson sense. The algorithm is defined by a graph, at least one observation, and a diffusion model for threat. A link to well-known spectral detection methods is provided, and the equivalence of the random walk and harmonic solutions to the Bayesian formulation is proven. A general diffusion model is introduced that utilizes spatio-temporal relationships between vertices, and is used for a specific space-time formulation that leads to significant performance improvements on coordinated covert networks. This performance is demonstrated using a new hybrid mixed-membership blockmodel introduced to simulate random covert networks with realistic properties.
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Summary

A novel unified Bayesian framework for network detection is developed, under which a detection algorithm is derived based on random walks on graphs. The algorithm detects threat networks using partial observations of their activity, and is proved to be optimum in the Neyman-Pearson sense. The algorithm is defined by a...

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Bayesian discovery of threat networks

IPC design validation and flight testing final report

March 31, 1978
  |
Project Report
Author:
John W. Andrews
…
Published in:
MIT Lincoln Laboratory Report ATC-85
Topic:
air traffic control
R&D area:
R&D group:

Summary

A series of flight tests were conducted to evaluate the collision avoidance system known as Intermittent Positive Control (subsequently re-named Automatic Traffic Advisory and Resolution Service, ATARS). These tests involved both professional test pilots and subject pilots selected from the aviation community. This report includes analysis of the collision avoidance algorithm, pilot visual acquisition performance, and pilot reaction to avoidance instructions.
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Summary

A series of flight tests were conducted to evaluate the collision avoidance system known as Intermittent Positive Control (subsequently re-named Automatic Traffic Advisory and Resolution Service, ATARS). These tests involved both professional test pilots and subject pilots selected from the aviation community. This report includes analysis of the collision avoidance...

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IPC design validation and flight testing final report

Plan for flight testing intermittent positive control

June 1, 1975
  |
Project Report
Author:
John W. Andrews
…
Published in:
MIT Lincoln Laboratory Report ATC-46
Topic:
air traffic control
R&D area:
R&D group:

Summary

Intermittent Positive Control is an automated aircraft collision avoidance system requiring the participation of the aircraft pilots involved. The operational interface between pilots and the IPC system is being evaluated in a series of live flight tests. The Lincoln Laboratory DABS Experimental Facility, augmented to include the IPC function, is the test bed for these evaluation flights. This document described the objectives and methods of the IPC flight testing being conducted by Lincoln Laboratory.
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Summary

Intermittent Positive Control is an automated aircraft collision avoidance system requiring the participation of the aircraft pilots involved. The operational interface between pilots and the IPC system is being evaluated in a series of live flight tests. The Lincoln Laboratory DABS Experimental Facility, augmented to include the IPC function, is...

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Plan for flight testing intermittent positive control
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