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Articles 1 - 3 of 3
Full-Text Articles in Computer Engineering
High-Speed Digital And Mixed-Signal Components For X– And Ku–Band Direct Digital Synthesizers In Indium Phosphide Dhbt Technology, Steven Eugene Turner
High-Speed Digital And Mixed-Signal Components For X– And Ku–Band Direct Digital Synthesizers In Indium Phosphide Dhbt Technology, Steven Eugene Turner
Electronic Theses and Dissertations
Recently reported double heterojunction bipolar transistor (DHBT) devices manufactured in Indium Phosphide (InP) technology with ft and fmax both over 300 GHz enable advanced high-speed digital and mixed-signal circuits. In this thesis, the use of InP DHBT devices for high-speed accumulator circuits and X– and Ku–band direct digital synthesizer (DDS) circuits are investigated. At these frequencies, new technological challenges in the design of digital and mixed-signal circuits arise in areas including power consumption and clock distribution. This thesis addresses the speed/power tradeoffs in high-speed accumulator designs, the design of DDS circuits, and clock distribution simulation. The results of six accumulator …
Nsf-Cnpq Collaborative Research On Integrating Geospatial Information, Max J. Egenhofer
Nsf-Cnpq Collaborative Research On Integrating Geospatial Information, Max J. Egenhofer
University of Maine Office of Research Administration: Grant Reports
Under this project, researchers at the University of Maine and the Brazilian National Institute for Space Research (INPE) are collaborating to study new models for integrating geographic information. The two research teams complement each other, providing a unique synergy in conceptual modeling and systems development. Long-term visits by Brazilian researchers assure a tight cooperation, and provide for integrated research and education. The work focuses on the semantics of spatial data collections that are stored in geographic information systems or spatial databases. Such collections often have diverse database schemas and lack conventions that would make them easily compatible, so that they …
Remote Sensing And Data Collection In A Marine Science Application, Isaac Abraham Horn
Remote Sensing And Data Collection In A Marine Science Application, Isaac Abraham Horn
Electronic Theses and Dissertations
In every field of science, research is driven by the data scjentists are able to collect. Specifically in the area of marine science, researchers at the Darling Marine Center (DMC) in Walpole, Maine study thc emergence events of undersea organisms. This thesis describes the development of a system integrating hardware infrastructure and existing software technology with a new software application, for the purpose of data acquisition at the DMC. In their research, a Tracor Acoustic Profiling System (TAPS), measures the water column density by utilizing sonar pulscs at several different frequencies. A serial interface provides access to the systems command …