27,365 research outputs found
Selectable towline spin chute system
An emergency spin recovery parachute is presented that is housed within a centrally mounted housing on the aft end of an aircraft and connected to a ring fitting within the housing. Two selectively latching shackles connected to separate towlines are openly disposed adjacent the ring fitting. The towlines extend in opposite directions from the housing along the aircraft wing to attachment points adjacent the wing-tips where the other end of each towline is secured. Upon pilot command, one of the open shackles latches to the ring fitting to attach the towline connected thereto, and a second command signal deploys the parachute. Suitable break-away straps secure the towlines to the aircraft surface until the parachute is deployed and the resulting force on the towline attached to the parachute overcomes the straps and permits the towline to extend to the point of attachment to exert sufficient drag on the spinning aircraft to permit the pilot to regain control of the aircraft. To employ the parachute as a drag chute to reduce landing speeds, both shackles and their respective towlines are latched to the ring fitting
Composite CDMA - A statistical mechanics analysis
Code Division Multiple Access (CDMA) in which the spreading code assignment
to users contains a random element has recently become a cornerstone of CDMA
research. The random element in the construction is particular attractive as it
provides robustness and flexibility in utilising multi-access channels, whilst
not making significant sacrifices in terms of transmission power. Random codes
are generated from some ensemble, here we consider the possibility of combining
two standard paradigms, sparsely and densely spread codes, in a single
composite code ensemble. The composite code analysis includes a replica
symmetric calculation of performance in the large system limit, and
investigation of finite systems through a composite belief propagation
algorithm. A variety of codes are examined with a focus on the high
multi-access interference regime. In both the large size limit and finite
systems we demonstrate scenarios in which the composite code has typical
performance exceeding sparse and dense codes at equivalent signal to noise
ratio.Comment: 23 pages, 11 figures, Sigma Phi 2008 conference submission -
submitted to J.Stat.Mec
Medical Image Data and Datasets in the Era of Machine Learning-Whitepaper from the 2016 C-MIMI Meeting Dataset Session.
At the first annual Conference on Machine Intelligence in Medical Imaging (C-MIMI), held in September 2016, a conference session on medical image data and datasets for machine learning identified multiple issues. The common theme from attendees was that everyone participating in medical image evaluation with machine learning is data starved. There is an urgent need to find better ways to collect, annotate, and reuse medical imaging data. Unique domain issues with medical image datasets require further study, development, and dissemination of best practices and standards, and a coordinated effort among medical imaging domain experts, medical imaging informaticists, government and industry data scientists, and interested commercial, academic, and government entities. High-level attributes of reusable medical image datasets suitable to train, test, validate, verify, and regulate ML products should be better described. NIH and other government agencies should promote and, where applicable, enforce, access to medical image datasets. We should improve communication among medical imaging domain experts, medical imaging informaticists, academic clinical and basic science researchers, government and industry data scientists, and interested commercial entities
Characterization of the CBC2 readout ASIC for the CMS strip-tracker high-luminosity upgrade
The CMS Binary Chip 2 (CBC2) is a full-scale prototype ASIC developed for the front-end readout of the high-luminosity upgrade of the CMS silicon strip tracker. The 254-channel, 130 nm CMOS ASIC is designed for the binary readout of double-layer modules, and features cluster-width discrimination and coincidence logic for detecting high-PT track candidates. The chip was delivered in January 2013 and has since been bump-bonded to a dual-chip hybrid and extensively tested. The CBC2 is fully functional and working to specification: we present the result of electrical characterization of the chip, including gain, noise, threshold scan and power consumption, together with the performance of the stub finding logic. Finally we will outline the plan for future developments towards the production version
Optical readout of charge and spin in a self-assembled quantum dot in a strong magnetic field
We present a theory and experiment demonstrating optical readout of charge
and spin in a single InAs/GaAs self-assembled quantum dot. By applying a
magnetic field we create the filling factor 2 quantum Hall singlet phase of the
charged exciton. Increasing or decreasing the magnetic field leads to
electronic spin-flip transitions and increasing spin polarization. The
increasing total spin of electrons appears as a manifold of closely spaced
emission lines, while spin flips appear as discontinuities of emission lines.
The number of multiplets and discontinuities measures the number of carriers
and their spin. We present a complete analysis of the emission spectrum of a
single quantum dot with N=4 electrons and a single hole, calculated and
measured in magnetic fields up to 23 Tesla.Comment: 9 pages, 3 figures, submitted to Europhysics Letter
Environmental Consequences of Ethanol from Corn Grain, Ethanol from Lignocellulosic Biomass, and Conventional Gasoline
The Energy Policy Act of 2005 includes a provision designed to double the production and use of ethanol in fuels by 2012, and that beginning in 2013, a minimum of 250 million gallons per year of ethanol be produced from lignocellulosic sources such as corn stover, wheat straw, and switchgrass. This study was conducted to determine the environmental and health consequences of using ethanol as an additive to gasoline. Comparisons are made among conventional gasoline (CG), a blend of 10 percent corn-ethanol and 90 percent CG (E10-corn), and a blend of 10 percent ethanol produced from lignocellulosic biomass (LCB) and 90 CG (E10-LCB).Resource /Energy Economics and Policy,
Driving forces in free visual search : An ethology
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