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Institution

Mitre Corporation

CompanyBedford, Massachusetts, United States
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.


Papers
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Journal ArticleDOI
TL;DR: IMPS is an interactive mathematical proof system intended as a general-purpose tool for formulating and applying mathematics in a familiar fashion and provides some support for modeling applications in computer science.
Abstract: IMPS is an interactive mathematical proof system intended as a general-purpose tool for formulating and applying mathematics in a familiar fashion. The logic of IMPS is based on a version of simple type theory with partial functions and subtypes. Mathematical specification and inference are performed relative to axiomatic theories, which can be related to one another via inclusion and theory interpretation. IMPS provides relatively large primitive inference steps to facilitate human control of the deductive process and human comprehension of the resulting proofs. An initial theory library containing over a thousand repeatable proofs covers significant portions of logic, algebra, and analysis and provides some support for modeling applications in computer science.

175 citations

Journal ArticleDOI
TL;DR: This article presents an efficient, trainable system for sentence boundary disambiguation, called Satz, which makes simple estimates of the parts of speech of the tokens immediately preceding and following each punctuation mark, and uses these estimates as input to a machine learning algorithm that then classifies the punctuated mark.
Abstract: The sentence is a standard textual unit in natual language processing applications In many language the punctuation mark that indicates the end-of-sentence boundary is ambiguous; thus the tokenizers of most NLP systems must be equipped with special sentence boundary recognition rules for every new text collectionAs an alternative, this article presents an efficient, trainable system for sentence boundary disambiguation The system, called Satz, makes simple estimates of the parts of speech of the tokens immediately preceding and following each punctuation mark, and uses these estimates as input to a machine learning algorithm that then classifies the punctuation mark Satz is very fast both in training and sentence analysis, and its combined robustness and accuracy surpass existing techniques The system needs only a small lexicon and training corpus, and has been shown to transfer quickly and easily from English to other languages, as demonstrated on Franch and German

173 citations

Journal ArticleDOI
01 Aug 2002
TL;DR: A fully complex multi-layer perceptron (MLP) structure that yields a simplified complex-valued back-propagation (BP) algorithm is presented and the advantage of ETFs over split complex AF is shown in numerical examples where nonlinear magnitude and phase distortions of non-constant modulus modulated signals are successfully restored.
Abstract: Designing a neural network (NN) to process complex-valued signals is a challenging task since a complex nonlinear activation function (AF) cannot be both analytic and bounded everywhere in the complex plane {\bb C}. To avoid this difficulty, ‘splitting’, i.e., using a pair of real sigmoidal functions for the real and imaginary components has been the traditional approach. However, this ‘ad hoc’ compromise to avoid the unbounded nature of nonlinear complex functions results in a nowhere analytic AF that performs the error back-propagation (BP) using the split derivatives of the real and imaginary components instead of relying on well-defined fully complex derivatives. In this paper, a fully complex multi-layer perceptron (MLP) structure that yields a simplified complex-valued back-propagation (BP) algorithm is presented. The simplified BP verifies that the fully complex BP weight update formula is the complex conjugate form of real BP formula and the split complex BP is a special case of the fully complex BP. This generalization is possible by employing elementary transcendental functions (ETFs) that are almost everywhere (a.e.) bounded and analytic in {\bb C}. The properties of fully complex MLP are investigated and the advantage of ETFs over split complex AF is shown in numerical examples where nonlinear magnitude and phase distortions of non-constant modulus modulated signals are successfully restored.

172 citations

Patent
05 Jan 2000
TL;DR: In this paper, a hand-held antenna specifically for GPS applications is provided which includes a microstrip patch antenna having a ground board, a single radiating patch spaced from the ground board and a resonant cavity defined between the ground boards and the single RSUs.
Abstract: A hand-held antenna specifically for GPS applications is provided which includes a microstrip patch antenna having a ground board, a single radiating patch spaced from the ground board and a resonant cavity defined between the ground board and the single radiating patch. Feed points are provided, one in the geometrical center of the radiating patch, and one, two, or four equidistantly spaced from the central feed point and disposed at 90° angular intervals. A feed network couples fundamental modes of excitation to the side feed points on the patch and a higher mode of excitation to the central feed point. Amplitude and phase controllers are provided in the feed network for amplitude and phase shifting between the fundamental and higher order modes of excitation in order to steer a spatial null in azimuth and elevation.

171 citations

Patent
12 Jul 2002
TL;DR: In this paper, single and dual frequency band spatial null steering antenna arrays are disclosed, comprised of primary resonant quadrifilar helix antennas and auxiliary resonant patch antennas, which comprise stacked patches in the dual-band embodiments.
Abstract: Single and dual frequency band spatial null steering antenna arrays are disclosed, comprised of primary resonant quadrifilar helix antennas and auxiliary resonant patch antennas, which comprise stacked patches in the dual-band embodiments. Several feed networks are described for producing, preferably, circularly polarized radiation in satellite frequency bands (e.g., L1 and L2) with pattern nulls steerable to desired elevation angles. Various top and bottom-fed quadrifilar helix antennas configurations are also described.

170 citations


Authors

Showing all 4896 results

NameH-indexPapersCitations
Sushil Jajodia10166435556
Myles R. Allen8229532668
Barbara Liskov7620425026
Alfred D. Steinberg7429520974
Peter T. Cummings6952118942
Vincent H. Crespi6328720347
Michael J. Pazzani6218328036
David Goldhaber-Gordon5819215709
Yeshaiahu Fainman5764814661
Jonathan Anderson5719510349
Limsoon Wong5536713524
Chris Clifton5416011501
Paul Ward5240812400
Richard M. Fujimoto5229013584
Bhavani Thuraisingham5256310562
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20234
202210
202195
2020139
2019145
2018132