Publications

Wireless technology, such as local area telecommunication networks and surveillance cameras, causes severe interference for weather radars, because they use the same operational radio frequencies. One or two disturbances can be removed from the radar image, but the number and power of the interfering wireless devices are growing all over...

In cyber security, achieving the desired balance between system security and system performance in dynamic threat environments is a long-standing open challenge for cyber defenders. Typically an increase in system security comes at the price of decreased system performance, and vice versa, easily resulting in systems that are misaligned to...

Antenna radiation patterns are typically measured using network analyzers, which are both expensive and physically large in size. These drawbacks can limit this test equipment's usage in universities that cannot afford to make such a purchase, as well as within applications that require mobile antenna measurements. An alternative approach is...

Many in-band full-duplex wireless systems transmit and receive on a single antenna to minimize redundancy and maintain compact form factors. For effective operation, all of these systems need to maximize transmit-to-receive isolation, which is limited by non-ideal antenna matching and non-zero circulator leakage. Several isolation-improvement techniques are investigated in this...

A switched array tile which is part of a large aperture for near-field microwave imaging is presented. The tile is based on the Boundary Array (BA), a sparse array topology for hardware efficient realization of imaging apertures. The larger array formed with the tile samples a scene with no redundancy...

In this paper, we present the Cyber Analyst Real-Time Integrated Notebook Application (CARINA). CARINA is a collaborative investigation system that aids in decision making by co-locating the analysis environment with centralized cyber data sources, and providing next generation analysts with increased visibility to the work of others.

Over several decades, speaker recognition performance has steadily improved for applications using telephone speech. A big part of this improvement has been the availability of large quantities of speaker-labeled data from telephone recordings. For new data applications, such as audio from room microphones, we would like to effectively use existing...

In this paper we describe the most recent MIT Lincoln Laboratory language recognition system developed for the NIST 2015 Language Recognition Evaluation (LRE). The submission features a fusion of five core classifiers, with most systems developed in the context of an i-vector framework. The 2015 evaluation presented new paradigms. First...

Speech provides a potential simple and noninvasive "on-body" means to identify and monitor neurological diseases. Here we develop a model for a class of vocal biomarkers exploiting modulations in speech, focusing on Major Depressive Disorder (MDD) as an application area. Two model components contribute to the envelope of the speech...

This work demonstrates a novel broadband optical switch, based on dynamic-scattering effect in liquid crystals (LCs). Dynamic-scattering-mode technology was developed for display applications over four decades ago, but was displaced in favor of the twisted-nematic LCs. However, with the recent development of more stable LCs, dynamic scattering provides advantages over...