1,176 research outputs found
Digital Image Processing Using NTEC Facilities
Digital image enhancement refers to the improvement of a given image for human interpretation. Digital image processing facilities are those in which hardware and software computing elements are combined in such a way as to enable the processing of digital images. This report describes the use of the Naval Training Equipment Center (NTEC) Computer Systems Laboratory computing facilities to enhance digital images. Described are two major hardware systems, the IKONAS RDS-3000 raster display graphics system and the VAX-11/780, and the digital image processing program (DIMPRP) written by the author. Digital image enhancement theory and practice are addressed through a discussion of the DIMPRP software. Finally, enhancements to the NTEC digital image processing facility such as improvements in hardware reliability, documentation, and increased speed of program execution are discussed
Approaching âkit-typeâ labelling with 68Ga: the DATA chelators
The DATA chelators are a novel class of tri-anionic ligands based on 6-amino-1,4-diazepine-triacetic acid, which have been introduced recently for the chelation of 68Ga. Compared with macrocyclic chelators based on the cyclen scaffold (i.e., DOTA, DO3A, and DO2A derivatives), DATA chelators undergo quantitative radiolabelling more rapidly and under milder conditions. In this study, a systematic evaluation of the labelling of four DATA chelatorsâDATAM, DATAP, DATAPh, and DATAPPhâwith 68Ga is presented. The results highlight the extraordinary potential of this new class of chelators for application in molecular imaging using 68Ga positron emission tomography (PET)
Implementing a Reconciliation and Balancing Model in the U.s. Industry Accounts
As part of the U.S. Bureau of Economic Analysisâ integration initiative (Yuskavage, 2000; Moyer et al., 2004a, 2004b; Lawson et al., 2006), the Industry Accounts Directorate is drawing upon the Stone method (Stone et al., 1942) and Chen (2006) to reconcile the gross operating surplus component of value-added from the 2002 expenditure-based benchmark input-output accounts and the 2002 income-based gross domestic product-by-industry accounts. The objective of the reconciliation is to use information regarding the relative reliabilities of underlying data in both the benchmark input-output use table and the gross domestic product-by-industry accounts in a balanced input-output framework in order to improve intermediate input estimates and gross operating surplus estimates in both accounts. Given a balanced input-output framework, the Stone method also provides a tool for balancing the benchmark use table. This paper presents work by the Industry Accounts Directorate to develop and implement the reconciliation and balancing model. The paper provides overviews of the benchmark use table and gross domestic product-by-industry accounts, including features of external source data and adjustment methodologies that are relevant for the reconciliation. In addition, the paper presents the empirical model that the Industry Accounts Directorate is building and briefly describes the technology used to solve the model. Preliminary work during development of the model shows that reconciling and balancing a large system with disaggregated data is computationally feasible and efficient in pursuit of an economically accurate and reliable benchmark use table and gross domestic product-by-industry accounts.
Usutu virus: an arbovirus on the rise
This article belongs to the Special Issue Transmission Dynamics of Insect VirusesThe Usutu virus (USUV) is a flavivirus that is drawing increasing attention because of its potential for emergence. First isolated in Africa, it was introduced into Europe where it caused significant outbreaks in birds, such as in Austria in 2001. Since then, its geographical distribution has rapidly expanded, with increased circulation, especially in the last few years. Similar to West Nile virus (WNV), the USUV enzootic transmission cycle involves Culex mosquitoes as vectors, and birds as amplifying reservoir hosts, with humans and other mammals likely being dead-end hosts. A similarity in the ecology of these two viruses, which co-circulate in several European countries, highlights USUVâs potential to become an important human pathogen. While USUV has had a severe impact on the blackbird population, the number of human cases remains low, with most infections being asymptomatic. However, some rare cases of neurological disease have been described, both in healthy and immuno-compromised patients. Here, we will discuss the transmission dynamics and the current state of USUV circulation in Europe
Advanced modulation technology development for earth station demodulator applications
The purpose of this contract was to develop a high rate (200 Mbps), bandwidth efficient, modulation format using low cost hardware, in 1990's technology. The modulation format chosen is 16-ary continuous phase frequency shift keying (CPFSK). The implementation of the modulation format uses a unique combination of a limiter/discriminator followed by an accumulator to determine transmitted phase. An important feature of the modulation scheme is the way coding is applied to efficiently gain back the performance lost by the close spacing of the phase points
VLBI Probes of Jet Physics in Neutrino-Candidate Blazars
In recent years, evidence has accumulated that some high-energy cosmic
neutrinos can be associated with blazars. The strongest evidence for an
individual association was found in the case of the blazar TXS 0506+056 in
2017. In July 2019, another track-like neutrino event (IC190730A) was found
spatially coincident with the well-known bright flat-spectrum radio quasar PKS
1502+106. PKS 1502+106 was not found to be in a particularly elevated gamma-ray
state, but exhibited a remarkably bright radio outburst at the time of the
neutrino detection, similar to TXS 0506+056. We have performed a
multi-frequency VLBI study from 15 GHz up to 86 GHz on TXS 0506+056, PKS
1502+106 and one additional neutrino-candidate blazar (PKS 0215+015) to study
the radio structure of neutrino candidate blazars in response to their neutrino
association. We have obtained target of opportunity observations with the VLBA
for all three sources within 1 month from their associated neutrino
events and are performing multi-epoch studies of the jet kinematics at 15 GHz
as part of the MOJAVE program. Here, we present first results on TXS 0506+056
at 86 GHz and one additional 43 GHz image obtained 27 days after IC170922A,
closer in time to the neutrino event than previously published images. We also
give an overview about our recent work on PKS 1502+106 and PKS 0215+015.Comment: 8 pages, 1 figure, 1 table, Proceedings of 38th International Cosmic
Ray Conference (ICRC2023
Development of Lumped Element Kinetic Inductance Detectors for NIKA
Lumped-element kinetic inductance detectors(LEKIDs) have recently shown
considerable promise as direct absorption mm-wavelength detectors for
astronomical applications. One major research thrust within the N\'eel Iram
Kids Array (NIKA) collaboration has been to investigate the suitability of
these detectors for deployment at the 30-meter IRAM telescope located on Pico
Veleta in Spain. Compared to microwave kinetic inductance detectors (MKID),
using quarter wavelength resonators, the resonant circuit of a LEKID consists
of a discrete inductance and capacitance coupled to a feedline. A high and
constant current density distribution in the inductive part of these resonators
makes them very sensitive. Due to only one metal layer on a silicon substrate,
the fabrication is relatively easy. In order to optimize the LEKIDs for this
application, we have recently probed a wide variety of individual resonator and
array parameters through simulation and physical testing. This included
determining the optimal feed-line coupling, pixel geometry, resonator
distribution within an array (in order to minimize pixel cross-talk), and
resonator frequency spacing. Based on these results, a 144-pixel Aluminum array
was fabricated and tested in a dilution fridge with optical access, yielding an
average optical NEP of ~2E-16 W/Hz^1/2 (best pixels showed NEP = 6E-17 W/Hz^1/2
under 4-8 pW loading per pixel). In October 2010 the second prototype of LEKIDs
has been tested at the IRAM 30 m telescope. A new LEKID geometry for 2
polarizations will be presented. Also first optical measurements of a titanium
nitride array will be discussed.Comment: 5 pages, 12 figures; ISSTT 2011 Worksho
Do all components of the metabolic syndrome cluster together in U.S. Hispanics/Latinos? Results from the Hispanic Community Health study/Study of Latinos
Metabolic syndrome (MetS), the clustering of several risk factors for cardiovascular disease, is highly prevalent in Hispanics/Latinos. We tested whether all components significantly loaded on the syndrome in Hispanics/Latinos and whether their contribution differed by sex and Hispanic ancestry. We also examined associations of metabolic syndrome with prevalent diabetes and coronary heart disease (CHD) in Hispanics/Latinos
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