Mitre Corporation

About: Mitre Corporation is a company organization based out in Bedford, Massachusetts, United States. It is known for research contribution in the topics: Air traffic control & National Airspace System. The organization has 4884 authors who have published 6053 publications receiving 124808 citations. The organization is also known as: Mitre & MITRE.

Efficient wideband jammer nulling when using stretch processing

Abstract: Techniques are described for performing adaptive jammer nulling over extremely wide bandwidths on radar systems which use linear frequency modulated (LFM) waveforms and stretch processing. It is assumed that the range uncertainty of the target is a small percentage of the equivalent range extent of the uncompressed pulse. The assumption allows the cancellation to take place following stretch processing in either the time domain using a narrowband sliding filter that keeps up with the chirp fate or in the frequency domain. The new approach supports nulling performance over gigahertz of bandwidth comparable to that previously achieved over a few megahertz using approximately the same number of spatial degrees of freedom.

Dictionary-Based Compression for Long Time-Series Similarity

Abstract: Long time-series data sets are common in many domains, especially scientific domains. Applications in these fields often require comparing trajectories using similarity measures. Existing methods perform well for short time series but their evaluation cost degrades rapidly for longer time series. In this work, we develop a new time-series similarity measure called the Dictionary Compression Score (DCS) for determining time-series similarity. We also show that this method allows us to accurately and quickly calculate similarity for both short and long time series. We use the well-known Kolmogorov Complexity in information theory and the Lempel-Ziv compression framework as a basis to calculate similarity scores. We show that off-the-shelf compressors do not fair well for computing time-series similarity. To address this problem, we developed a novel dictionary-based compression technique to compute time-series similarity. We also develop heuristics to automatically identify suitable parameters for our method, thus, removing the task of parameter tuning found in other existing methods. We have extensively compared DCS with existing similarity methods for classification. Our experimental evaluation shows that for long time-series data sets, DCS is accurate, and it is also significantly faster than existing methods.

Dependability Evaluation of Integrated Hardware/Software Systems

Abstract: A methodology for predicting the dependability (reliability and availability) of an integrated realtime hardware/software system using a semi-Markov process is described. This methodology was used to evaluate the reliability of the shuttle mission simulators at the NASA Johnson Space Center.

Virtual private network call processing in the intelligent network

Abstract: The author explains the main features of the virtual private network (VPN) and proposes and defines a new integrated service control point call processing design model for the intelligent network. The model allows multiple application services to be executed simultaneously and provides real-time behavior. The features and capabilities of this model of call processing are addressed, and it is applied to the VPN application services. >

Viewing model for virtual environment displays

Abstract: We present a viewing model that is appropriate for several types of displays used in virtual environment systems, including head-mounted displays and head-tracked stationary displays. The model accounts for arbitrary size, placement, and orientation of the display images, and thus is suitable for various display designs. We provide algorithms for calculating stereoscopic viewing and projection matrices. The tracking algorithm models the position and orientation of the tracker's emitter and the displacement between the sensor and the user's eyes. The algorithms are presented as parameterized homogeneous transforms. We also discuss features that can be used to avoid accommodation/convergence conflicts. The advantages of this viewing model and algorithm are the elimination of possible vertical parallax, an undistorted perception of depth, and reduction of eye fatigue due to excessive parallax. All of these factors contribute to improved comfort and utility for the operator.