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.

Automated camera cleaning system

Abstract: Embodiments of an automated camera cleaning system are provided. In one embodiment, the automated camera cleaning system includes an optical path, an optically-transmissive lens shield through which the optical path extends, a housing in which the optically-transmissive lens shield is at least partially disposed, and a motor coupled to the lens shield. When energized, the motor moves the optically-transmissive lens shield relative to the housing to vary the region of the optically-transmissive lens shield positioned in the optical path.

Optical distortion coefficients of high-power laser windows

Abstract: This paper concerns the problem of describing and evaluating thermal lensing phenomena that occur as a result of the absorption of laser light in solid windows. The aberration function expansion method is applied for deriving the two optical distortion coefficients x+ and xthat characterize the degradation in light intensity at the Gaussian focus of an initially diffraction-limited laser beam passing through a weakly absorbing stress-birefringent window. In a pulsed mode of operation, the concept of an effective optical distortion coefficient Xeff, which properly combines the coefficients x+ and x- in terms of potential impact on focal irradiances, then leads to the definition of a figure of merit for distortion. The theory and calculations presented in this and earlier papers provide simple analytical tools for predicting the optical performance of a windowmaterial candidate in a specific system's environment.

THE PROGENITOR MASS OF SN 2011dh FROM STELLAR POPULATION ANALYSIS

Abstract: Using Hubble Space Telescope photometry, we characterize the age of the stellar association in the vicinity of supernova (SN) 2011dh and use it to infer the zero-age main-sequence mass (M ZAMS) of the progenitor star. We find two distinct and significant star formation (SF) events with ages of 29 and 13+2 ? 1 M ?, respectively. These two bursts represent 18+4 ? 9% (young) and 64+10 ? 14% (old) of the total SF in the last 50?Myr. Adopting these fractions as probabilities suggests that the most probable M ZAMS is 13+2 ? 1 M ?. These results are most sensitive to the luminosity function along the well-understood main sequence (MS) and are less sensitive to uncertain late-stage stellar evolution. Therefore, they stand even if the progenitor suffered disruptive post-MS evolution (e.g., eruptive mass loss or binary Roche-lobe overflow). Progenitor identification will help to further constrain the appropriate population. Even though pre-explosion images show a yellow supergiant (YSG) at the site of the SN, panchromatic SN light curves suggest a more compact star as the progenitor. In spite of this, our results suggest an association between the YSG and the SN. Not only was the star located at the SN site, but reinforcing an association, the star's bolometric luminosity is consistent with the final evolutionary stage of the 17?Myr old starburst. If the YSG disappears, then M ZAMS = 13+2 ? 1 M ?, but if it persists, then our results allow the possibility that the progenitor was an unseen star of >29 M ?.

Bulkhead panel for use in a combustion chamber of a gas turbine engine

Abstract: The invention relates to a bulkhead panel for use in a combustion chamber of a gas turbine engine. The bulkhead panel comprises a first side and a second side, a plurality of panel holes extending from the first side to the second side through which cooling air flows, and a circumferential inner rail on said first side dividing said first side into a first cavity region having a plurality of the panel holes and a second cavity region having a plurality of the panel holes. Each of the panel holes has an exit nozzle which is angled so as to create a swirling flow of cooling air over the second side of the panel.

A framework for automatic TRIZ level of invention estimation of patents using natural language processing, knowledge-transfer and patent citation metrics

Abstract: Patents provide a wealth of information about design concepts, their physical realization, and their relationship to prior designs in the form of citations. Patents can provide useful input for several goals of next-generation computer-aided design (CAD) systems, yet more efficient tools are needed to facilitate patent search and ranking. In this paper, a novel framework is presented and implemented for classifying patents according to level of invention (LOI) as defined in the theory of inventive problem solving (TRIZ). Level of invention characterizes the creativity of a design concept based on the resolution of a design conflict and the disciplines used in resolving the conflict. The assessment of LOI for a series of patents provides a useful input for screening and ranking patents in databases to identify high-impact patents. However, the manual effort required for assigning LOI to each patent is laborious and time-consuming. In this paper, a novel method that combines text mining, natural language processing, creation of knowledge-transfer metrics, and application of machine learning approaches is presented and implemented for classifying patents according to LOI. Two case studies are presented in which LOI data is compiled for patents: dynamic magnetic information storage or retrieval using Giant Magnetoresistive (GMR) or Colossal Magnetoresistive (CMR) sensors formed of multiple thin films (USPC 360/324) and arbitration for access to a channel (USPC 370/462). The peak performance in 5-fold stratified cross-validation was found to be 73.38% in the first case study and 77.12% for the second.