Publications
Optical phased-array ladar
Summary
Summary
We demonstrate a ladar with 0.5 m class range resolution obtained by integrating a continuous-wave optical phased-array transmitter with a Geiger-mode avalanche photodiode receiver array. In contrast with conventional ladar systems, an array of continuous-wave sources is used to effectively pulse illuminate a target by electro-optically steering far-field fringes. From...
Finding good enough: a task-based evaluation of query biased summarization for cross language information retrieval
Summary
Summary
In this paper we present our task-based evaluation of query biased summarization for cross-language information retrieval (CLIR) using relevance prediction. We describe our 13 summarization methods each from one of four summarization strategies. We show how well our methods perform using Farsi text from the CLEF 2008 shared-task, which we...
Bayesian discovery of threat networks
Summary
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...
Increasing the coherence time in a magnetically-sensitive stimulated Raman transition in 85Rb
Summary
Summary
We experimentally study the Ramsey, spin echo, and CPMG pulse sequences of a magnetically sensitive transition of a cold 85Rb gas. We can increase the coherence time by up to a factor of 10 by using CPMG pulse sequences as compared to Ramsey or spin echo.
Energy efficiency benefits of subthreshold-optimized transistors for digital logic
Summary
Summary
The minimum energy point of an integrated circuit (IC) is defined as the value of the supply voltage at which the energy per operation of the circuit is minimized. Several factors influence what the value of this voltage can be, including the topology of the circuit itself, the input activity...
Quantitative evaluation of dynamic platform techniques as a defensive mechanism
Summary
Summary
Cyber defenses based on dynamic platform techniques have been proposed as a way to make systems more resilient to attacks. These defenses change the properties of the platforms in order to make attacks more complicated. Unfortunately, little work has been done on measuring the effectiveness of these defenses. In this...
Using deep belief networks for vector-based speaker recognition
Summary
Summary
Deep belief networks (DBNs) have become a successful approach for acoustic modeling in speech recognition. DBNs exhibit strong approximation properties, improved performance, and are parameter efficient. In this work, we propose methods for applying DBNs to speaker recognition. In contrast to prior work, our approach to DBNs for speaker recognition...
Talking Head Detection by Likelihood-Ratio Test(220.2 KB)
Summary
Summary
Detecting accurately when a person whose face is visible in an audio-visual medium is the audible speaker is an enabling technology with a number of useful applications. The likelihood-ratio test formulation and feature signal processing employed here allow the use of high-dimensional feature sets in the audio and visual domain...
A survey of cryptographic approaches to securing big-data analytics in the cloud
Summary
Summary
The growing demand for cloud computing motivates the need to study the security of data received, stored, processed, and transmitted by a cloud. In this paper, we present a framework for such a study. We introduce a cloud computing model that captures a rich class of big-data use-cases and allows...
Computing on masked data: a high performance method for improving big data veracity
Summary
Summary
The growing gap between data and users calls for innovative tools that address the challenges faced by big data volume, velocity and variety. Along with these standard three V's of big data, an emerging fourth "V" is veracity, which addresses the confidentiality, integrity, and availability of the data. Traditional cryptographic...