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The radar Correlation and Interpolation (C&I) algorithms deployed in the ASR-9 Processor Augmentation Card (9PAC)

June 29, 2001
  |
Project Report
Author:
Gabriel R. Elkin
Published in:
MIT Lincoln Laboratory Report ATC-299
Topic:
air traffic control
R&D area:
R&D group:

Summary

The Airport Surveillance Radar 9 (ASR-9) is a terminal radar that was deployed by the Federal Aviation Administration (FAA) during the early 1990's at more than 130 of the busiest airports in the United States. The ASR-9 Processor Augmentation Card (9-PAC), developed at MIT Lincoln Laboratory, is a processor board enhancement for the ASR-9 Array Signal Processor (ASP) that provides increases in processing speed, memory size, and programming. The increased capabilities of the 9PAC hardware made it possible for new surveillance algorithms to be developed in software to provide improved primary radar and beacon surveillance performance. The 9PAC project was developed in two phases. Phase I, which addressed the beacon reflection false target problem, was completed, and is currently being deployed nationwide by the FAA on a plug and play basis. Phase II addresses the primary radar surveillance problems, which include automation of the road and ground clutter censoring process, improving the rejection of false targets, and improving the detection and tracking of aircraft targets. The 9PAC also reduces the life-cycle maintenance cost of the ASR-9 in the Phase II configuration, in which a single 9PAC card replaces four ASP cards. This report describes the improvements to the radar Correlation and Interpolation (C&I) process, which is responsible for creating aircraft target reports and filtering out false targets. [Not Complete]
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Summary

The Airport Surveillance Radar 9 (ASR-9) is a terminal radar that was deployed by the Federal Aviation Administration (FAA) during the early 1990's at more than 130 of the busiest airports in the United States. The ASR-9 Processor Augmentation Card (9-PAC), developed at MIT Lincoln Laboratory, is a processor board...

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The radar Correlation and Interpolation (C&I) algorithms deployed in the ASR-9 Processor Augmentation Card (9PAC)

Speaker recognition from coded speech in matched and mismatched conditions

June 18, 2001
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Conference Paper
Author:
Robert B. Dunn
…
Published in:
Proc. 2001: A Speaker Odyssey, The Speaker Recognition Workshop, 18-22 June 2001, pp. 115-20.
Topic:
speaker recognition
R&D area:
R&D group:

Summary

We investigate the effect of speech coding on automatic speaker recognition when training and testing conditions are matched and mismatched. Experiments use standard speech coding algorithms (GSM, G.729, G.723, MELP) and a speaker recognition system based on Gaussian mixture models adapted from a universal background model. There is little loss in recognition performance for toll quality speech coders and slightly more loss when lower quality speech coders are used. Speaker recognition from coded speech using handset dependent score normalization is examined, and we find that this significantly improves performance, particularly when there is a mismatch between training and testing conditions.
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Summary

We investigate the effect of speech coding on automatic speaker recognition when training and testing conditions are matched and mismatched. Experiments use standard speech coding algorithms (GSM, G.729, G.723, MELP) and a speaker recognition system based on Gaussian mixture models adapted from a universal background model. There is little loss...

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Speaker recognition from coded speech in matched and mismatched conditions

Extending the DARPA off-line intrusion detection evaluations

June 12, 2001
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Conference Paper
Author:
Joshua W. Haines
…
Published in:
DARPA Information Survivability Conf. and Exposition II, 12-14 June 2001, pp. 35-45.
Topic:
cyber security
R&D area:
R&D group:

Summary

The 1998 and 1999 DARPA off-line intrusion detection evaluations assessed the performance of intrusion detection systems using realistic background traffic and many examples of realistic attacks. This paper discusses three extensions to these evaluations. First, the Lincoln Adaptable Real-time Information Assurance Testbed (LARIAT) has been developed to simplify intrusion detection development and evaluation. LARIAT allows researchers and operational users to rapidly configure and run real-time intrusion detection and correlation tests with robust background traffic and attacks in their laboratories. Second, "Scenario Datasets" have been crafted to provide examples of multiple component attack scenarios instead of the atomic , attacks as found in past evaluations. Third, extensive analysis of the 1999 evaluation data and results has provided understanding of many attacks, their manifestations, and the features used to detect them. This analysis will be used to develop models of attacks, intrusion detection systems, and intrusion detection system alerts. Successful models could reduce the need for expensive experimentation, allow proof-of-concept analysis and simulations, and form the foundation of a theory of intrusion detection.
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Summary

The 1998 and 1999 DARPA off-line intrusion detection evaluations assessed the performance of intrusion detection systems using realistic background traffic and many examples of realistic attacks. This paper discusses three extensions to these evaluations. First, the Lincoln Adaptable Real-time Information Assurance Testbed (LARIAT) has been developed to simplify intrusion detection...

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Extending the DARPA off-line intrusion detection evaluations

SARA: Survivable Autonomic Response Architecture

June 12, 2001
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Conference Paper
Author:
Scott M. Lewandowski
…
Published in:
DARPA Information Survivability Conf. and Exposition II, 12-14 June 2001, pp. 77-88.
Topic:
cyber security
R&D area:
R&D group:

Summary

This paper describes the architecture of a system being developed to defend information systems using coordinated autonomic responses. The system will also be used to test the hypothesis that an effective defense against fast, distributed information attacks requires rapid, coordinated, network-wide responses. The core components of the architecture are a run-time infrastructure (RTI), a communication language, a system model, and defensive components. The RTI incorporates a number of innovative design concepts and provides fast, reliable, exploitation-resistant communication and coordination services to the components defending the network, even when challenged by a distributed attack. The architecture can be tailored to provide scalable information assurance defenses for large, geographically distributed, heterogeneous networks with multiple domains, each of which uses different technologies and requires different policies. The architecture can form the basis of a field-deployable system. An initial version is being developed for evaluation in a testbed that will be used to test the autonomic coordination and response hypothesis.
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Summary

This paper describes the architecture of a system being developed to defend information systems using coordinated autonomic responses. The system will also be used to test the hypothesis that an effective defense against fast, distributed information attacks requires rapid, coordinated, network-wide responses. The core components of the architecture are a...

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SARA: Survivable Autonomic Response Architecture

Detecting low-profile probes and novel denial-of-service attacks

June 1, 2001
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Conference Paper
Author:
Raj Basu
…
Published in:
IEEE SMC IA&S Workshop, June 2001.
Topic:
intrusion detection & monitoring
R&D area:
R&D group:

Summary

Attackers use probing attacks to discover host addresses and services available on each host. Once this information is known, an attacker can then issue a denial-of-service attack against the network, a host, or a service provided by a host. These attacks prevent access to the attacked part of the network. Until recently, only simple, easily defeated mechanisms were used for detecting probe attacks. Attackers defeat these mechanisms by creating stealthy low-profile attacks that include only a few, carefully crafted packets sent over an extended period of time. Furthermore, most mechanisms do not allow intrusion analysts to trade off detection rates for false alarm rates. We present an approach to detect stealthy attacks, an architecture for achieving real-time detections with a confidence measure, and the results of evaluating the system. Since the system outputs confidence values, an analyst can trade false alarm rate against detection rate.
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Summary

Attackers use probing attacks to discover host addresses and services available on each host. Once this information is known, an attacker can then issue a denial-of-service attack against the network, a host, or a service provided by a host. These attacks prevent access to the attacked part of the network...

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Detecting low-profile probes and novel denial-of-service attacks

Accurate modeling of dual dipole and slot elements used with photomixers for coherent terahertz output power

June 1, 2001
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Journal Article
Author:
Sean M. Duffy
…
Published in:
IEEE Trans. Microw. Theory Tech., Vol. 49, No. 6, June 2001, pp. 1032-8.
Topic:
antennas
R&D area:
R&D group:

Summary

Accurate circuit models derived from electromagnetic simulations have been used to fabricate photomixer sources with optimized high-impedance antennas. Output powers on the order of 1 uW were measured for various designs spanning 0.6-2.7 THz. The improvement in output power ranged from 3 to 10 dB over more conventionally designed photomixers using broad-band log-spiral antennas. Measured data on single dipoles, twin dipoles, and twin slots are in good agreement with the characteristics predicted by the design simulations.
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Summary

Accurate circuit models derived from electromagnetic simulations have been used to fabricate photomixer sources with optimized high-impedance antennas. Output powers on the order of 1 uW were measured for various designs spanning 0.6-2.7 THz. The improvement in output power ranged from 3 to 10 dB over more conventionally designed photomixers...

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Accurate modeling of dual dipole and slot elements used with photomixers for coherent terahertz output power

Infrared frequency selective surfaces fabricated using optical lithography and phase-shift masks

May 29, 2001
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Conference Paper
Author:
Steven Jay Spector
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Published in:
J. Vac. Sci. Technol. B, Vol. 19, No. 6, November/December 2001, pp. 2757-2760. (45th Int. Conf. on Electron, Ion, and Photon Beam Technology and Nanofabrication (EIPBN), 29 May-1 June 2001.)
Topic:
lithography
R&D area:
R&D group:

Summary

A frequency selective surface (FSS) structure has been fabricated for use in a thermophotovoltaic system. The FSS provides a means for reflecting the unusable light below the band gap of the thermophotovoltaic cell while transmitting the usable light above the band gap. This behavior is relatively independent of the light's incident angle. The fabrication of the FSS was done using optical lithography and a phase-shift mask. The FSS cell consisted of circular slits spaced by 1100 nm. The diameter and width of the circular slits were 870 and 120 nm, respectively. The FSS was predicted to pass wavelengths near 7 um and reflect wavelengths outside of this pass band. The FSSs fabricated performed as expected with a pass band centered near 5 um.
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Summary

A frequency selective surface (FSS) structure has been fabricated for use in a thermophotovoltaic system. The FSS provides a means for reflecting the unusable light below the band gap of the thermophotovoltaic cell while transmitting the usable light above the band gap. This behavior is relatively independent of the light's...

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Infrared frequency selective surfaces fabricated using optical lithography and phase-shift masks

Speaker indexing in large audio databases using anchor models

May 7, 2001
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Conference Paper
Author:
Douglas E. Sturim
…
Published in:
Proc. IEEE Int. Conf. on Acoustics, Speech and Signal Processing, ICASSP, Vol. 1, 7-11 May 2001, pp. 429-432.
Topic:
speaker recognition
R&D area:
R&D group:

Summary

This paper introduces the technique of anchor modeling in the applications of speaker detection and speaker indexing. The anchor modeling algorithm is refined by pruning the number of models needed. The system is applied to the speaker detection problem where its performance is shown to fall short of the state-of-the-art Gaussian Mixture Model with Universal Background Model (GMM-UBM) system. However, it is further shown that its computational efficiency lends itself to speaker indexing for searching large audio databases for desired speakers. Here, excessive computation may prohibit the use of the GMM-UBM recognition system. Finally, the paper presents a method for cascading anchor model and GMM-UBM detectors for speaker indexing. This approach benefits from the efficiency of anchor modeling and high accuracy of GMM-UBM recognition.
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Summary

This paper introduces the technique of anchor modeling in the applications of speaker detection and speaker indexing. The anchor modeling algorithm is refined by pruning the number of models needed. The system is applied to the speaker detection problem where its performance is shown to fall short of the state-of-the-art...

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Speaker indexing in large audio databases using anchor models

ASR-9 Processor Augmentation Card (9-PAC) phase II scan-scan correlator algorithms

April 26, 2001
  |
Project Report
Author:
Robert D. Grappel
Published in:
MIT Lincoln Laboratory Report ATC-298
Topic:
algorithms
R&D area:
R&D group:

Summary

This report documents the scan-scan correlator (tracker) algorithm developed for Phase II of the ASR-9 Processor Augmentation Card (9-PAC) project. The improved correlation and tracking algorithms in 9-PAC Phase II decrease the incidence of false-alarm tracks and increase the detection of real aircraft. The tracker processing for 9-PAC Phase II defined in this document builds upon the prototype 9-PAC Phase II tracker describedin ATC-245. Tracker algorithms from Mode S (ATC-65) are also used in Phase II. This document describes the three main processing tasks of the tracker: initialization, input/output, and the actual correlation/tracking. The tracker itself is further broken down into four main functions: report-to-track association, report-to-track correlation, track update, and track initiation. Each of these functions is described in detail and is further broken down into sub-functions. In addition to the algorithm descriptions, the 9-PAC Phase II tracker system requirements are reviewed, and main data structures used in the 9-PAC Phase II tracker are defined.
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Summary

This report documents the scan-scan correlator (tracker) algorithm developed for Phase II of the ASR-9 Processor Augmentation Card (9-PAC) project. The improved correlation and tracking algorithms in 9-PAC Phase II decrease the incidence of false-alarm tracks and increase the detection of real aircraft. The tracker processing for 9-PAC Phase II...

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ASR-9 Processor Augmentation Card (9-PAC) phase II scan-scan correlator algorithms

Interlingua-based broad-coverage Korean-to-English translation in CCLINC

March 18, 2001
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Conference Paper
Author:
Young-Suk Lee
…
Published in:
Proc. First Int. Conf. on Human Language Technology, 18-21 March 2001.
Topic:
machine translation
R&D area:
R&D group:

Summary

At MIT Lincoln Laboratory, we have been developing a Korean-to-English machine translation system CCLINC (Common Coalition Language System at Lincoln Laboratory). The CCLINC Korean-to-English translation system consists of two core modules, language understanding and generation modules mediated by a language neutral meaning representation called a semantic frame. The key features of the system include: (i) Robust efficient parsing of Korean (a verb final language with overt case markers, relatively free word order, and frequent omissions of arguments). (ii) High quality translation via word sense disambiguation and accurate word order generation of the target language. (iii) Rapid system development and porting to new domains via knowledge-based automated acquisition of grammars. Having been trained on Korean newspaper articles on "missiles" and "chemical biological warfare," the system produces the translation output sufficient for content understanding of the original document.
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Summary

At MIT Lincoln Laboratory, we have been developing a Korean-to-English machine translation system CCLINC (Common Coalition Language System at Lincoln Laboratory). The CCLINC Korean-to-English translation system consists of two core modules, language understanding and generation modules mediated by a language neutral meaning representation called a semantic frame. The key features...

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Interlingua-based broad-coverage Korean-to-English translation in CCLINC
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