267 research outputs found
Evaluating LAANC Utilization & Compliance for Small Unmanned Aircraft Systems in Controlled Airspace
On July 23, 2019, the Federal Aviation Administration (FAA) expanded the Low Altitude Authorization and Notification Capability (LAANC)âthe system that processes airspace approvals for sUAS operators in controlled airspaceâto include recreational operations. Researchers sought to collect and evaluate 30 days of UAS operational activity in controlled airspace using UAS detection equipment. Detected UAS flight data was compared against UAS Facility Maps and LAANC approval data to assess UAS operator compliance and behavior patterns. Researchers documented 94 LAANC approvals and detected 271 UAS flights within the sample area during the sampling period. The research team noted that UAS detections exceeded LAANC authorizations by a rate of approximately four-to-one. Only 7.0% of detected UAS operations could be correlated to a LAANC authorization, possibly indicating significant rates of non-compliance. Additionally, researchers determined that 34.3% (n =93) of detected UAS operations exceeded maximum altitudes prescribed for their respective location. Forty-four percent (n =41) of UASFM altitude exceedances occurred above 500 feet AGL, posing potential risk to manned aviation operations in the National Airspace System. Researchers advocate for the implementation of additional measures to curtail non-compliance, including additional UAS operator training, deterrence, and enforcement measures. The research team intends to expand this study to additional airports via related research projects within the FAAâs ASSURE Program
Response to Professor Olsen's Commentary on âRandom Sampling â Is It Worth It?â
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94518/1/ppe12019.pd
Evaluating LAANC Compliance and Air Traffic Collision Hazards Posed by Small Unmanned Aircraft Operations in Controlled Airspace
On July 23, 2019, the Federal Aviation Administration (FAA) expanded the Low Altitude Authorization and Notification Capability (LAANC)âthe system that processes airspace approvals for sUAS operators in controlled airspaceâto include recreational operations. Under LAANC, sUAS operators submit flight request information to one of 14 LAANC Service Suppliers via a mobile or online application. Flight request data is checked against UAS Facility Maps, NOTAMs, and Temporary Flight Restrictions to ensure compliance. Small UAS operators then receive a digital, automated authorization in near-real time. As of May 23, 2019, 591 airports across the United States are included in the LAANC system. Researchers sought to collect and evaluate sUAS operational activity in controlled airspace using UAS detection equipment. Detected sUAS flight data was compared against airspace information, temporary flight restrictions, UAS Facility Maps, and LAANC approval data to assess sUAS operator compliance and behavior patterns. Small UAS detections and LAANC authorization data was further compared against air traffic data to identify potential UAS flight interference and collision hazards with air traffic
Cognitive Information Processing
Contains reports on six research projects.National Institutes of Health (Grant 1 PO1 GM-14940-01)National Institutes of Health (Grant 1 PO1 GM-15006-01)Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E)Project MAC, an M. I. T. research programAdvanced Research Projects Agency, Department of Defense, under Office of Naval Research Contract Nonr-4102-(01
Regional Climate Trends and Scenarios for the U.S. National Climate Assessment Part 4. Climate of the U.S. Great Plains
This document is one of series of regional climate descriptions designed to provide input that can be used in the development of the National Climate Assessment (NCA). As part of a sustained assessment approach, it is intended that these documents will be updated as new and well-vetted model results are available and as new climate scenario needs become clear. It is also hoped that these documents (and associated data and resources) are of direct benefit to decision makers and communities seeking to use this information in developing adaptation plans.
There are nine reports in this series, one each for eight regions defined by the NCA, and one for the contiguous U.S. The eight NCA regions are the Northeast, Southeast, Midwest, Great Plains, Northwest, Southwest, Alaska, and Hawaiâi/Pacific Islands.
These documents include a description of the observed historical climate conditions for each region and a set of climate scenarios as plausible futures â these components are described in more detail below.
While the datasets and simulations in these regional climate documents are not, by themselves, new, (they have been previously published in various sources), these documents represent a more complete and targeted synthesis of historical and plausible future climate conditions around the specific regions of the NCA.
There are two components of these descriptions. One component is a description of the historical climate conditions in the region. The other component is a description of the climate conditions associated with two future pathways of greenhouse gas emissions
Cognitive Information Processing
Contains reports on seven research projects.National Institutes of Health (Grant 5 POI GM14940-03)National Institutes of Health (Grant 5 P01 GM15006-02)Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E
Cognitive Information Processing
Contains research objectives, summary of research and reports on two research projects.National Institutes of Health (Grant 5 PO1 GM-14940-02)National Institutes of Health (Grant 5 P01 GM-15006-02)Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E)National Institutes of Health (Grant 5 TO1 GM-01555-02
Tensile Fracture of Welded Polymer Interfaces: Miscibility, Entanglements and Crazing
Large-scale molecular simulations are performed to investigate tensile
failure of polymer interfaces as a function of welding time . Changes in the
tensile stress, mode of failure and interfacial fracture energy are
correlated to changes in the interfacial entanglements as determined from
Primitive Path Analysis. Bulk polymers fail through craze formation, followed
by craze breakdown through chain scission. At small welded interfaces are
not strong enough to support craze formation and fail at small strains through
chain pullout at the interface. Once chains have formed an average of about one
entanglement across the interface, a stable craze is formed throughout the
sample. The failure stress of the craze rises with welding time and the mode of
craze breakdown changes from chain pullout to chain scission as the interface
approaches bulk strength. The interfacial fracture energy is calculated
by coupling the simulation results to a continuum fracture mechanics model. As
in experiment, increases as before saturating at the average
bulk fracture energy . As in previous simulations of shear strength,
saturation coincides with the recovery of the bulk entanglement density. Before
saturation, is proportional to the areal density of interfacial
entanglements. Immiscibiltiy limits interdiffusion and thus suppresses
entanglements at the interface. Even small degrees of immisciblity reduce
interfacial entanglements enough that failure occurs by chain pullout and
Cognitive Information Processing
Contains research objectives, summary of research and reports on four research projects.National Institutes of Health (Grant 5 PO1 GM14940-02)National Institutes of Health (Grant 5 P01 GM15006-03)Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E)National Institutes of Health (Grant 5 T01 GM01555-03
Implementing Providerâbased Sampling for the National Children's Study: Opportunities and Challenges
Background:â The National Children's Study (NCS) was established as a national probability sample of births to prospectively study children's health starting from in utero to age 21. The primary sampling unit was 105 study locations (typically a county). The secondary sampling unit was the geographic unit (segment), but this was subsequently perceived to be an inefficient strategy. Methods and Results:â This paper proposes that secondâstage sampling using prenatal care providers is an efficient and costâeffective method for deriving a national probability sample of births in the US. It offers a rationale for providerâbased sampling and discusses a number of strategies for assembling a sampling frame of providers. Also presented are special challenges to providerâbased sampling pregnancies, including optimising key sample parameters, retaining geographic diversity, determining the types of providers to include in the sample frame, recruiting women who do not receive prenatal care, and using community engagement to enrol women. There will also be substantial operational challenges to sampling provider groups. Conclusion:â We argue that probability sampling is mandatory to capture the full variation in exposure and outcomes expected in a national cohort study, to provide valid and generalisable risk estimates, and to accurately estimate policy (such as screening) benefits from associations reported in the NCS.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94504/1/ppe12005.pd
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