6,256 research outputs found
FAME, a microprocessor based front-end analysis and modeling environment
Higher order software (HOS) is a methodology for the specification and verification of large scale, complex, real time systems. The HOS methodology was implemented as FAME (front end analysis and modeling environment), a microprocessor based system for interactively developing, analyzing, and displaying system models in a low cost user-friendly environment. The nature of the model is such that when completed it can be the basis for projection to a variety of forms such as structured design diagrams, Petri-nets, data flow diagrams, and PSL/PSA source code. The user's interface with the analyzer is easily recognized by any current user of a structured modeling approach; therefore extensive training is unnecessary. Furthermore, when all the system capabilities are used one can check on proper usage of data types, functions, and control structures thereby adding a new dimension to the design process that will lead to better and more easily verified software designs
Baby-Step Giant-Step Algorithms for the Symmetric Group
We study discrete logarithms in the setting of group actions. Suppose that
is a group that acts on a set . When , a solution
to can be thought of as a kind of logarithm. In this paper, we study
the case where , and develop analogs to the Shanks baby-step /
giant-step procedure for ordinary discrete logarithms. Specifically, we compute
two sets such that every permutation of can be
written as a product of elements and . Our
deterministic procedure is optimal up to constant factors, in the sense that
and can be computed in optimal asymptotic complexity, and and
are a small constant from in size. We also analyze randomized
"collision" algorithms for the same problem
Strange Quarks Nuggets in Space: Charges in Seven Settings
We have computed the charge that develops on an SQN in space as a result of
balance between the rates of ionization by ambient gammas and capture of
ambient electrons. We have also computed the times for achieving that
equilibrium and binding energy of the least bound SQN electrons. We have done
this for seven different settings. We sketch the calculations here and give
their results in the Figure and Table II; details are in the Physical Review
D.79.023513 (2009).Comment: Six pages, one figure. To appear in proceedings of the 2008 UCLA
coference on dark matter and dark energ
Inference with interference between units in an fMRI experiment of motor inhibition
An experimental unit is an opportunity to randomly apply or withhold a
treatment. There is interference between units if the application of the
treatment to one unit may also affect other units. In cognitive neuroscience, a
common form of experiment presents a sequence of stimuli or requests for
cognitive activity at random to each experimental subject and measures
biological aspects of brain activity that follow these requests. Each subject
is then many experimental units, and interference between units within an
experimental subject is likely, in part because the stimuli follow one another
quickly and in part because human subjects learn or become experienced or
primed or bored as the experiment proceeds. We use a recent fMRI experiment
concerned with the inhibition of motor activity to illustrate and further
develop recently proposed methodology for inference in the presence of
interference. A simulation evaluates the power of competing procedures.Comment: Published by Journal of the American Statistical Association at
http://www.tandfonline.com/doi/full/10.1080/01621459.2012.655954 . R package
cin (Causal Inference for Neuroscience) implementing the proposed method is
freely available on CRAN at https://CRAN.R-project.org/package=ci
Dequalinium: A Novel, High-affinity Blocker of CNGA1 Channels
Cyclic nucleotide–gated (CNG) channels have been shown to be blocked by diltiazem, tetracaine, polyamines, toxins, divalent cations, and other compounds. Dequalinium is an organic divalent cation which suppresses the rat small conductance Ca2+-activated K+ channel 2 (rSK2) and the activity of protein kinase C. In this study, we have tested the ability of dequalinium to block CNGA1 channels and heteromeric CNGA1+CNGB1 channels. When applied to the intracellular side of inside-out excised patches from Xenopus oocytes, dequalinium blocks CNGA1 channels with a K1/2 ≈ 190 nM and CNGA1+CNGB1 channels with a K1/2 ≈ 385 nM, at 0 mV. This block occurs in a state-independent fashion, and is voltage dependent with a zδ ≈ 1. Our data also demonstrate that dequalinium interacts with the permeant ion probably because it occupies a binding site in the ion conducting pathway. Dequalinium applied to the extracellular surface also produced block, but with a voltage dependence that suggests it crosses the membrane to block from the inside. We also show that at the single-channel level, dequalinium is a slow blocker that does not change the unitary conductance of CNGA1 channels. Thus, dequalinium should be a useful tool for studying permeation and gating properties of CNG channels
Microscopic and Macroscopic Signatures of Antiferromagnetic Domain Walls
Magnetotransport measurements on small single crystals of Cr, the elemental
antiferromagnet, reveal the hysteretic thermodynamics of the domain structure.
The temperature dependence of the transport coefficients is directly correlated
with the real-space evolution of the domain configuration as recorded by x-ray
microprobe imaging, revealing the effect of antiferromagnetic domain walls on
electron transport. A single antiferromagnetic domain wall interface resistance
is deduced to be of order at a
temperature of 100 K.Comment: 3 color figure
IR Kuiper Belt Constraints
We compute the temperature and IR signal of particles of radius and
albedo at heliocentric distance , taking into account the
emissivity effect, and give an interpolating formula for the result. We compare
with analyses of COBE DIRBE data by others (including recent detection of the
cosmic IR background) for various values of heliocentric distance, ,
particle radius, , and particle albedo, . We then apply these
results to a recently-developed picture of the Kuiper belt as a two-sector disk
with a nearby, low-density sector (40<R<50-90 AU) and a more distant sector
with a higher density. We consider the case in which passage through a
molecular cloud essentially cleans the Solar System of dust. We apply a simple
model of dust production by comet collisions and removal by the
Poynting-Robertson effect to find limits on total and dust masses in the near
and far sectors as a function of time since such a passage. Finally we compare
Kuiper belt IR spectra for various parameter values.Comment: 34 pages, LaTeX, uses aasms4.sty, 11 PostScript figures not embedded.
A number of substantive comments by a particularly thoughtful referee have
been addresse
Reducing Obesity Risks During Childhood: The Role of Public and Private Health Insurance
In a widely publicized decision issued in 2004, the United States Department of Health and Human Services removed language from the Medicare Coverage Issues Manual which stated that obesity is not an illness, a pronouncement that paves the way for Medicare coverage of evidence-based obesity treatments. This determination by HHS also has important implications for public and private insurance coverage of health care services and interventions that have the potential to reduce the risk of lifelong obesity in children.
This Report assesses the implications of the 2004 HHS obesity ruling into the context of public and private health insurance for children. It begins with an overview of what is known about obesity risk in childhood, as well as its short-term and long-term health consequences and then reviews the evidence of effective health interventions for children at risk. The Report then considers the implications of the 2004 decision for private health insurance coverage for children, followed by a more extended discussion of its implications for children covered under Medicaid and the State Children\u27s Health Insurance Program (SCHIP). The Report concludes with a discussion of strategies for engaging both public and private insurers in a systematic effort to increase investment in preventive health services for children at risk of obesity
SPECIFIC TRAINING CAN IMPROVE SENSORIMOTOR CONTROL IN TYPE 2 DIABETIC PATIENTS
Diabetes mellitus often is associated with proprioceptive and sensory deficits as a result of distal diabetic polyneuropathy (DPN). The aim of this prospective controlled longitudinal trial was to evaluate a specific sport intervention program regarding sensorimotor capabilities in type 2 diabetic patients compared to healthy controls. A higher incidence of fall-related injuries is given in the literature (Allet et al.2008; Allet et al 2009)
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