Raytheon

About: Raytheon is a company organization based out in Waltham, Massachusetts, United States. It is known for research contribution in the topics: Signal & Antenna (radio). The organization has 15290 authors who have published 18973 publications receiving 300052 citations.

Multimodal biometric identification for large user population using fingerprint, face and iris recognition

Abstract: Biometric systems based solely on one-modal biometrics are often not able to meet the desired performance requirements for large user population applications, due to problems such as noisy data, intra-class variations, restricted degrees of freedom, nonuniversity, spoof attacks, and unacceptable error rates. Multimodal biometrics refers to the use of a combination of two or more biometric modalities in a single identification system. The most compelling reason to combine different modalities is to improve the recognition accuracy. This can be done when features of different biometrics are statistically independent. This paper overviews and discusses the various scenarios that are possible in multimodal biometric systems using fingerprint, face and iris recognition, the levels of fusion that are possible and the integration strategies that can be adopted to fuse information and improve overall system accuracy. This paper also discusses how the image quality of fingerprint, face and iris used in the multimodal biometric systems affects the overall identification accuracy and the need of staffing for the secondary human validation. For a large user population identification system, which often has more than tens or hundreds of millions of subject images already enrolled in the matcher databases and has to process more than hundreds of thousands of identification requests, the system's identification accuracy and the need of staffing levels to properly operate the system are two of the most important factors in determining whether a system is properly designed and integrated

Characterization of GaAs devices by a versatile pulsed I-V measurement system

Abstract: The authors build and utilized a pulsed I-V system which is capable of reaching any current-voltage point of three-terminal devices from any arbitrarily chosen DC bias point. The system, which can be used on wafer, serves as an invaluable tool for device modeling and process diagnostics. Direct dependence of the pulsed I-V curves on the DC bias was found in GaAs MESFETs and HEMTs (high-electron mobility transistors). >

The Detection of Inside-out Disk Growth in M33

Abstract: We present resolved stellar photometry of 4 fields along the major axis of the M33 disk from images taken with the Advanced Camera for Surveys aboard the Hubble Space Telescope The photometry provides a detailed census of the red clump in all fields and reaches the ancient main sequence in the outermost field Through detailed modeling of the color-magnitude diagrams, we find that the percentage of the stellar mass formed prior to z=1 changes from 71 +/- 9% in the innermost field to 16 +/- 6% in the outermost field The disk shows a clear trend of increasing scale-length with time, evolving from 10 +/- 01 kpc 10 Gyr ago to 18 +/- 01 kpc at times more recent than 5 Gyr ago, in agreement with analytical predictions for disk growth Beyond the disk truncation radius, however, the stellar density profile steepens with time and the age gradient reverses, in agreement with recent simulations The late and slow growth of the stellar disk may be due in part to the low mass of M33

Method and apparatus for an improved single pole double throw micro-electrical mechanical switch

Abstract: A single pole, double throw micro-electromechanical (MEM) switch. The inventive switch includes a first contact providing a first terminal of the switch. A second contact provides a second terminal of said switch. A cantilever beam provides a third terminal of the switch. The inventive switch includes a system for electrostatically pushing or pulling the beam to disengage the first contact and engage the second contact. In an illustrative implementation, the system for electrostatically operating the switch includes a first charge storage structure on the beam, a second charge storage structure on the switch, and an electrical supply for creating an electrical charge on the first and the second charge storage structures. The first and second charge storage structures are effective to create a force of repulsion therebetween on the application of an electrical charge thereto. The 'pull' electrostatic force closes the MEM switch. The 'push' force aids in opening the switch. The 'push' capability is the result of the use of like (same polarity) electrostatic charges on the control surfaces. The like charges provide an electrostatic repulsion force during the switch opening process.

Simple Tracking Filters: Closed-Form Solutions

Abstract: A closed-form steady-state solution is presented for a three-state tracking filter with continuous position measurements and exponentially correlated target acceleration. Some other related closed-form solutions are discussed, and some comparative performance data is presented for the discrete measurement case.