Publications

Millimeter-wave radiation and detection offers the possibility of detecting concealed weapons. Passive imaging measures the mm-wave radiation emitted from target objects. A passive mm-wave imager and the designs affecting the overall system performance are discussed. With low power receiver architecture and SiGe ICs, a focal plane based full staring array...

Details of a technical study that was part of a larger investigation assessing terminal weather services impacts of decommissioning the Terminal Doppler Weather Radar (TDWR) are presented. Effects on two key areas for safety and delay-reduction benefits are examined: low-altitude wind shear visibility and the Integrated Terminal Weather System (ITWS)...

Network-based intrusion detection systems (NIDSs) are one component of a comprehensive network security solution. The use of IPsec, which encrypts network traffic, renders network intrusion detection virtually useless unless traffic is decrypted at network gateways. One alternative to NIDSs, host-based intrusion detection systems (HIDSs), provides some of the functionality of...

A description of the MIT Lincoln Laboratory system used in the person identification task of the recent CLEAR 2007 Evaluation is documented in this paper. This task is broken into audio, visual, and multimodal subtasks. The audio identification system utilizes both a GMM and a SVM subsystem, while the visual...

Cryogenically cooled solid-state lasers promise a revolution in power scalability while maintaining a good beam quality because of significant improvements in efficiency and thermo-optic properties. This is particularly true forYb3+ lasers because of their relatively lowquantum defect and relatively broadband absorption even at cryogenic temperatures. Thermo-optic properties of host materials...

Low-bit-rate speech coding, at rates below 4 kb/s, is needed for both communication and voice storage applications. At such low rates, full encoding of the speech waveform is not possible; therefore, low-rate coders rely instead on parametric models to represent only the most perceptually relevant aspects of speech. While there...

Cross-channel degradation is one of the significant challenges facing speaker recognition systems. We study this problem in the support vector machine (SVM) context and nuisance variable compensation in high-dimensional spaces more generally. We present an approach to nuisance variable compensation by removing nuisance attribute-related dimensions in the SVM expansion space...

In this chapter, we focus on the area of text-independent speaker verification, with an emphasis on unconstrained telephone conversational speech. We begin by providing a general likelihood ratio detection task framework to describe the various components in modern text-independent speaker verification systems. We next describe the general hierarchy of speaker...

We present results from a new Interagency Language Roundtable (ILR) based comprehension test. This new test design presents questions at multiple ILR difficulty levels within each document. We incorporated Arabic machine translation (MT) output from three independent research sites, arbitrarily merging these materials into one MT condition. We contrast the...

Operational testing of the Runway Status Lights (RWSL) system at the Dallas-Fort Worth (DFW) airport has detected a number of cases where faults in the ASDE-X/DFW surveillance data have led to erroneous operation of the status lights. Among the surveillance problems noted during testing at DFW were: (a) false tracks...