Abstract: A topical cluster hierarchy (TCH) is constructed by recursive subclustering of document clusters until a termination condition is detected. The clusters have centroids of topic proximity with respect to at least one user-specified topic. Subclustering starts after thresholds of minimal cluster topic proximity or minimal cluster coherence are met, thus avoiding processing of low-utility clusters. Subclustering terminates when sufficient topic proximity, coherence, or cluster depth is reached. A tool utilizes the TCH to control topic-directed searching, topic-directed filtering, analyzing, summarizing, or categorizing, of documents.

Abstract: A weighted multicategory querying (WMQ) tool generates alternates of an initial query through spelling correction, grammar correction, natural language processing, ambiguous term resolution, term normalization, keyword reordering, synonyms, and similar terms. The WMQ tool generates additional queries in different weighted categories such as keyword combination, query programming language (QPL), metadata, or embedding space. Query result individual topic proximity scores are combined with category weights to calculate a combined topic proximity score, which is employed to rank the query result. Embedding space query weight is increased for queries classified as broad. QPL query weight or metadata query weight is increased for queries which contain part or all of a metadata field name. Language models are leveraged for query generation, topic proximity scoring, or both.

Abstract: A six degree-of-freedom optical tracker system includes LEDs that are mounted on a structure, and are each configured to emit light. An LED controller is coupled to the LEDs and supplies drive current to each of the LEDs in a manner that causes the LEDs to sequentially and individually emit light. A single position sensing device that is spaced apart from each of the LEDs receives the light emitted from each of the LEDs and supplies position data for each LED. A processor receives the position data and determines the position and orientation of the structure relative to the single position sensing device.

Abstract: A six degree-of-freedom optical tracker system includes LEDs that are mounted on a structure, and are each configured to emit light. An LED controller is coupled to the LEDs and supplies drive current to each of the LEDs in a manner that causes the LEDs to sequentially and individually emit light. A single position sensing device that is spaced apart from each of the LEDs receives the light emitted from each of the LEDs and supplies position data for each LED. A processor receives the position data and determines the position and orientation of the structure relative to the single position sensing device.

Abstract: In some examples, a system configured to remove at least some air and other gases that are dissolved in fuel prior to introducing the fuel into a closed fuel system, such as a closed fuel system of an unmanned aerial vehicle. The system includes a vacuum chamber configured to contain a fuel, a vacuum source attached lo the vacuum chamber and configured to draw a vacuum on a headspace over the fuel in the vacuum chamber, and a fuel pump configured to pump the fuel from the vacuum chamber into a closed fuel container without introducing air into the closed fuel container. In some examples, the pump introduces a fuel substantially free of dissolved gases into the closed fuel system.