Software Defined Radio Implementation of Carrier and Timing Synchronization for Distributed Arrays

The communication range of wireless networks can be greatly improved by using distributed beamforming from a set of independent radio nodes. One of the key challenges in establishing a beamformed communication link from separate radios is achieving carrier frequency and sample timing synchronization. This paper describes an implementation that addresses both carrier frequency and sample timing synchronization simultaneously using RF signaling between designated master and slave nodes. By using a pilot signal transmitted by the master node, each slave estimates and tracks the frequency and timing offset and digitally compensates for them. A real-time implementation of the proposed system was developed in GNU Radio and tested with Ettus USRP N210 software defined radios. The measurements show that the distributed array can reach a residual frequency error of 5 Hz and a residual timing offset of 1/16 the sample duration for 70 percent of the time. This performance enables distributed beamforming for range extension applications.Comment: Submitted to 2019 IEEE Aerospace Conferenc

Broadening Participation in Biology Education Research: Engaging Community College Students and Faculty

Nearly half of all undergraduates are enrolled at community colleges (CCs), including the majority of U.S. students who represent groups underserved in the sciences. Yet only a small minority of studies published in discipline-based education research journals address CC biology students, faculty, courses, or authors. This marked underrepresentation of CC biology education research (BER) limits the availability of evidence that could be used to increase CC student success in biology programs. To address this issue, a diverse group of stakeholders convened at the Building Capacity for Biology Education Research at Community Colleges meeting to discuss how to increase the prevalence of CC BER and foster participation of CC faculty as BER collaborators and authors. The group identified characteristics of CCs that make them excellent environments for studying biology teaching and learning, including student diversity and institutional cultures that prioritize teaching, learning, and assessment. The group also identified constraints likely to impede BER at CCs: limited time, resources, support, and incentives, as well as misalignment between doing research and CC faculty identities as teachers. The meeting culminated with proposing strategies for faculty, administrators, journal editors, scientific societies, and funding agencies to better support CC BER

Traffic Optimization for Signalized Corridors (TOSCo) Phase 2 Project

DTFH6114H00002This report provides a roadmap to details contained in four TOSCo Phase 2 detailed reports that focus on specific aspects of the four key technical objectives undertaken in the TOSCo Phase 2 Project. The four key technical objectives that the project team focused their efforts on in the project were: 1. Implement TOSCo vehicle algorithm in vehicles 2. Implement TOSCo infrastructure algorithm in infrastructure components 3. Verify and refine TOSCo system in a closed course setting then exporting it onto an actual corridor 4. Assess TOSCo functional safety and performance using real-world observations and actual on-road dat

Taxonomy based on science is necessary for global conservation

Peer reviewe

An evaluation of reduced amounts of advance traffic control for short duration and stop-and-go maintenance operations

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Bibliography: leaves 109-110.Not availabl

An evaluation of reduced amounts of advance traffic control for short duration and stop-and-go maintenance operations

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Bibliography: leaves 109-110.Not availabl

Data Sharing of Traveler Information with the Public and Private Sectors: State of the Practice

This report presents the results of its examination of the current state of the practice of traveler information data sharing with the public and private sectors. A review of the literature was initially performed followed by an analysis of responses to a survey instrument that was designed and administered to practitioners in the field, primarily representatives from public sector agencies, who are in the business of collecting traveler information data. Survey results have addressed the subjects of what data is shared, with whom it is shared, why it is shared, how it is institutionally arranged and managed, how effective the sharing enterprise has been, and how the enterprise can be improved. More work is needed and a next step could be the development of an action plan to implement the lessons learned

Data Sharing of Traveler Information with the Public and Private Sectors: State of the Practice

This report presents the results of its examination of the current state of the practice of traveler information data sharing with the public and private sectors. A review of the literature was initially performed followed by an analysis of responses to a survey instrument that was designed and administered to practitioners in the field, primarily representatives from public sector agencies, who are in the business of collecting traveler information data. Survey results have addressed the subjects of what data is shared, with whom it is shared, why it is shared, how it is institutionally arranged and managed, how effective the sharing enterprise has been, and how the enterprise can be improved. More work is needed and a next step could be the development of an action plan to implement the lessons learned

Data Sharing of Traveler Information with the Public and Private Sectors: State of the Practice

This report presents the results of its examination of the current state of the practice of traveler information data sharing with the public and private sectors. A review of the literature was initially performed followed by an analysis of responses to a survey instrument that was designed and administered to practitioners in the field, primarily representatives from public sector agencies, who are in the business of collecting traveler information data. Survey results have addressed the subjects of what data is shared, with whom it is shared, why it is shared, how it is institutionally arranged and managed, how effective the sharing enterprise has been, and how the enterprise can be improved. More work is needed and a next step could be the development of an action plan to implement the lessons learned.traveler information, data sharing, survey