Publications

Refine Results

(Filters Applied) Clear All

Feedback-based social media filtering tool for improved situational awareness

Published in:
15th Annual IEEE Int. Symp. on Technologies for Homeland Security, HST 2016, 10-12 May 2016.

Summary

This paper describes a feature-rich model of data relevance, designed to aid first responder retrieval of useful information from social media sources during disasters or emergencies. The approach is meant to address the failure of traditional keyword-based methods to sufficiently suppress clutter during retrieval. The model iteratively incorporates relevance feedback to update feature space selection and classifier construction across a multimodal set of diverse content characterization techniques. This approach is advantageous because the aspects of the data (or even the modalities of the data) that signify relevance cannot always be anticipated ahead of time. Experiments with both microblog text documents and coupled imagery and text documents demonstrate the effectiveness of this model on sample retrieval tasks, in comparison to more narrowly focused models operating in a priori selected feature spaces. The experiments also show that even relatively low feedback levels (i.e., tens of examples) can lead to a significant performance boost during the interactive retrieval process.
READ LESS

Summary

This paper describes a feature-rich model of data relevance, designed to aid first responder retrieval of useful information from social media sources during disasters or emergencies. The approach is meant to address the failure of traditional keyword-based methods to sufficiently suppress clutter during retrieval. The model iteratively incorporates relevance feedback...

READ MORE

Polymer dielectrics for 3D-printed RF devices in the Ka band

Summary

Direct-write printing allows the fabrication of centimeter-wave radio devices. Most polymer dielectric polymer materials become lossy at frequencies above 10 GHz. Presented here is a printable dielectric material with low loss in the K a band (26.5–40 GHz). This process allows the fabrication of resonator filter devices and a radio antenna.
READ LESS

Summary

Direct-write printing allows the fabrication of centimeter-wave radio devices. Most polymer dielectric polymer materials become lossy at frequencies above 10 GHz. Presented here is a printable dielectric material with low loss in the K a band (26.5–40 GHz). This process allows the fabrication of resonator filter devices and a radio...

READ MORE

A key-centric processor architecture for secure computing

Published in:
2016 IEEE Int. Symp. on Hardware-Oriented Security and Trust, HOST 2016, 3-5 May 2016.

Summary

We describe a novel key-centric processor architecture in which each piece of data or code can be protected by encryption while at rest, in transit, and in use. Using embedded key management for cryptographic key handling, our processor permits mutually distrusting software written by different entities to work closely together without divulging algorithmic parameters or secret program data. Since the architecture performs encryption, decryption, and key management deeply within the processor hardware, the attack surface is minimized without significant impact on performance or ease of use. The current prototype implementation is based on the Sparc architecture and is highly applicable to small to medium-sized processing loads.
READ LESS

Summary

We describe a novel key-centric processor architecture in which each piece of data or code can be protected by encryption while at rest, in transit, and in use. Using embedded key management for cryptographic key handling, our processor permits mutually distrusting software written by different entities to work closely together...

READ MORE

Storage and Database Management for Big Data

Published in:
Big Data: Storage, Sharing, and Security

Summary

The ability to collect and analyze large amounts of data is a growing problem within the scientific community. The growing gap between data and user calls for innovative tools that address the challenges faced by big data volume, velocity, and verity. While there has been great progress in the world of database technologies in the past few years, there are still many fundamental considerations that must be made by scientists. For example, which of the seemingly infinite technologies are the best to use for my problem? Answers to such questions require careful understanding of the technology field in addition to the types of problems that are being solved. This chapter aims to address many of the pressing questions faced by individuals interesting in using sotrage or database technologies to solve their big data problems.
READ LESS

Summary

The ability to collect and analyze large amounts of data is a growing problem within the scientific community. The growing gap between data and user calls for innovative tools that address the challenges faced by big data volume, velocity, and verity. While there has been great progress in the world...

READ MORE

Wafer-scale aluminum nanoplasmonic resonators with optimized metal deposition

Summary

Spectroscopic ellipsometry is demonstrated to be an effective technique for assessing the quality of plasmonic resonances within aluminum nanostructures deposited with multiple techniques. The resonance quality of nanoplasmonic aluminum arrays is shown to be strongly dependent on the method of aluminum deposition. Three-layer metal-dielectric-metal nanopillar arrays were fabricated in a complementary metal-oxide semiconductor (CMOS) facility, with the arrays of nanopillars separated from a continuous metal underlayer by a thin dielectric spacer, to provide optimum field enhancement. Nanostructures patterned in optimized aluminum, which had been deposited with a high temperature sputtering process followed by chemical mechanical planarization, display different resonance and depolarization behavior than nanostructures deposited by the more conventional evaporation process. Full plasmonic band diagrams are mapped over a wide range of incidence angles and wavelengths using spectroscopic ellipsometry, and compared for aluminum nanostructures fabricated with two methods. The resonators fabricated from optimized aluminum exhibit a narrower bandwidth of both plasmonic resonance and depolarization parameters, indicating a higher quality resonance due to a stronger localization of the electric field. The optimized wafer-scale aluminum plasmonics fabrication should provide a pathway towards better quality devices for sensing and light detection in the ultraviolet and blue parts of the spectrum.
READ LESS

Summary

Spectroscopic ellipsometry is demonstrated to be an effective technique for assessing the quality of plasmonic resonances within aluminum nanostructures deposited with multiple techniques. The resonance quality of nanoplasmonic aluminum arrays is shown to be strongly dependent on the method of aluminum deposition. Three-layer metal-dielectric-metal nanopillar arrays were fabricated in a...

READ MORE

Cryptography for Big Data security

Published in:
Chapter 10 in Big Data: Storage, Sharing, and Security, 2016, pp. 214-87.

Summary

This chapter focuses on state-of-the-art provably secure cryptographic techniques for protecting big data applications. We do not focus on more established, and commonly available cryptographic solutions. The goal is to inform practitioners of new techniques to consider as they develop new big data solutions rather than to summarize the current best practice for securing data.
READ LESS

Summary

This chapter focuses on state-of-the-art provably secure cryptographic techniques for protecting big data applications. We do not focus on more established, and commonly available cryptographic solutions. The goal is to inform practitioners of new techniques to consider as they develop new big data solutions rather than to summarize the current...

READ MORE

A reverse approach to named entity extraction and linking in microposts

Published in:
Proc. of the 6th Workshop on "Making Sense of Microposts" (part of: 25th Int. World Wide Web Conf., 11 April 2016), #Microposts2016, pp. 67-69.

Summary

In this paper, we present a pipeline for named entity extraction and linking that is designed specifically for noisy, grammatically inconsistent domains where traditional named entity techniques perform poorly. Our approach leverages a large knowledge base to improve entity recognition, while maintaining the use of traditional NER to identify mentions that are not co-referent with any entities in the knowledge base.
READ LESS

Summary

In this paper, we present a pipeline for named entity extraction and linking that is designed specifically for noisy, grammatically inconsistent domains where traditional named entity techniques perform poorly. Our approach leverages a large knowledge base to improve entity recognition, while maintaining the use of traditional NER to identify mentions...

READ MORE

Named entity recognition in 140 characters or less

Published in:
Proc. of the 6th Workshop on "Making Sense of Microposts" (part of: 25th Int. World Wide Web Conf., 11 April 2016), #Microposts2016, pp. 78-79.

Summary

In this paper, we explore the problem of recognizing named entities in microposts, a genre with notoriously little context surrounding each named entity and inconsistent use of grammar, punctuation, capitalization, and spelling conventions by authors. In spite of the challenges associated with information extraction from microposts, it remains an increasingly important genre. This paper presents the MIT Information Extraction Toolkit (MITIE) and explores its adaptability to the micropost genre.
READ LESS

Summary

In this paper, we explore the problem of recognizing named entities in microposts, a genre with notoriously little context surrounding each named entity and inconsistent use of grammar, punctuation, capitalization, and spelling conventions by authors. In spite of the challenges associated with information extraction from microposts, it remains an increasingly...

READ MORE

Blind signal classification via sparse coding

Published in:
IEEE Int. Conf. Computer Communications, IEEE INFOCOM 2016, 10-15 April 2016.

Summary

We propose a novel RF signal classification method based on sparse coding, an unsupervised learning method popular in computer vision. In particular, we employ a convolutional sparse coder that can extract high-level features by computing the maximal similarity between an unknown received signal against an overcomplete dictionary of matched filter templates. Such dictionary can be either generated or trained in an unsupervised fashion from signal examples labeled with no ground truths. The computed sparse code then is applied to train SVM classifiers to discriminate RF signals. As a result, the proposed approach can achieve blind signal classification that requires no prior knowledge (e.g., MCS, pulse shaping) about the signals present in an arbitrary RF channel. Since modulated RF signals undergo pulse shaping to aid the matched filter detection by a receiver for the same radio protocol, our method can exploit variability in relative similarity against the dictionary atoms as the key discriminating factor for SVM. We present an empirical validation of our approach. The results indicate that we can separate different classes of digitally modulated signals from blind sampling with 70.3% recall and 24.6% false alarm at 10 dB SNR. If a labeled dataset were available for supervised classifier training, we can enhance the classification accuracy to 87.8% recall and 14.1% false alarm.
READ LESS

Summary

We propose a novel RF signal classification method based on sparse coding, an unsupervised learning method popular in computer vision. In particular, we employ a convolutional sparse coder that can extract high-level features by computing the maximal similarity between an unknown received signal against an overcomplete dictionary of matched filter...

READ MORE

Geiger-mode avalanche photodiode arrays integrated to all-digital CMOS circuits

Author:
Published in:
Sensors, Vol. 16, No. 495, 2016, doi:10.3390/s16040495.

Summary

This article reviews MIT Lincoln Laboratory's work over the past 20 years to develop photon-sensitive image sensors based on arrays of silicon Geiger-mode avalanche photodiodes. Integration of these detectors to all-digital CMOS readout circuits enable exquisitely sensitive solid-state imagers for lidar, wavefront sensing, and passive imaging.
READ LESS

Summary

This article reviews MIT Lincoln Laboratory's work over the past 20 years to develop photon-sensitive image sensors based on arrays of silicon Geiger-mode avalanche photodiodes. Integration of these detectors to all-digital CMOS readout circuits enable exquisitely sensitive solid-state imagers for lidar, wavefront sensing, and passive imaging.

READ MORE