336,559 research outputs found
Status of the Muon (g-2) Experiment
The status of the muon (g-2) experiment, E821 at the Brookhaven AGS, is
given. A new result with a precision of 5 parts per million has been obtained
with direct muon injection into the ring and is presented. The theoretical
motivation for the experiment, and a discussion of the sensitivity to
non-standard model physics is also discussed.Comment: 12 pages, Latex, special macros needed: LP99macros.tex, Invited
presentation at the XIX International Symposium on Lepton and Photon
Interactions at High Energy, Stanford University, August 199
Muscle Memory and the Local Concentration of Capital Punishment
The modern death penalty is not just concentrating in a handful of practicing states; it is disappearing in all but a few capitally active localities. Capital-punishment concentration, however, still surfaces more as the subject of casual observation than as the object of sophisticated academic inquiry. Normative and doctrinal analyses of the phenomenon are virtually nonexistent, in part because the current ability to measure and report concentration is so limited.
This Article is the first attempt to measure capital-punishment concentration rigorously, by combining different sources of county-level data and by borrowing quantitative tools that economists use to study market competition. The analysis yields three major findings: (1) capital sentencing is concentrating dramatically; (2) executions are concentrating more gradually; and (3) both trends persist within most capitally active states.
Certain normative and doctrinal conclusions follow from the empirical findings. The causes of concentration are likely to be more bureaucratic and path dependent than they are democratic and pragmatic, reflecting what I call the “muscle memory” of local institutional practice. If local muscle memory indeed explains concentration, such concentration violates basic punishment norms requiring equal treatment of similar offenders. This problem notwithstanding, existing death penalty jurisprudence does not account for local concentration. For concentration to have any influence on the outcome of constitutional inquiry, the Supreme Court would have to revise its working definition of “arbitrariness.
Persistence in systems with algebraic interaction
Persistence in coarsening 1D spin systems with a power law interaction
is considered. Numerical studies indicate that for sufficiently
large values of the interaction exponent ( in our
simulations), persistence decays as an algebraic function of the length scale
, . The Persistence exponent is found to be
independent on the force exponent and close to its value for the
extremal () model, . For smaller
values of the force exponent (), finite size effects prevent the
system from reaching the asymptotic regime. Scaling arguments suggest that in
order to avoid significant boundary effects for small , the system size
should grow as .Comment: 4 pages 4 figure
Implicit Smartphone User Authentication with Sensors and Contextual Machine Learning
Authentication of smartphone users is important because a lot of sensitive
data is stored in the smartphone and the smartphone is also used to access
various cloud data and services. However, smartphones are easily stolen or
co-opted by an attacker. Beyond the initial login, it is highly desirable to
re-authenticate end-users who are continuing to access security-critical
services and data. Hence, this paper proposes a novel authentication system for
implicit, continuous authentication of the smartphone user based on behavioral
characteristics, by leveraging the sensors already ubiquitously built into
smartphones. We propose novel context-based authentication models to
differentiate the legitimate smartphone owner versus other users. We
systematically show how to achieve high authentication accuracy with different
design alternatives in sensor and feature selection, machine learning
techniques, context detection and multiple devices. Our system can achieve
excellent authentication performance with 98.1% accuracy with negligible system
overhead and less than 2.4% battery consumption.Comment: Published on the IEEE/IFIP International Conference on Dependable
Systems and Networks (DSN) 2017. arXiv admin note: substantial text overlap
with arXiv:1703.0352
Long-term Solar Irradiance Variability: 1984-1989 Observations
Long-term variability in the total solar irradiance has been observed in the Earth Radiation Budget Experiment (ERBE) solar monitor measurements. The monitors have been used to measure the irradiance from the Earth Radiation Budget Satellite (ERBS) and the National Oceanic and Atmospheric Administration NOAA-9 and NOAA-10 spacecraft platforms since October 25, 1984, January 23, 1985, and October 22, 1986, respectively. Before September 1986, the ERBS irradiance values were found to be decreasing -0.03 percent per year. This period was marked by decreasing solar magnetic activity. Between September 1986 and mid-1989, the irradiance values increased approximately 0.1 percent. The latter period was marked by increasing solar activity which was associated with the initiations of the sunspot cycle number 22 and of a new 22-year Hale solar magnetic cycle. Therefore, long-term solar-irradiance variability appears to be correlated directly with solar activity. The maximum smoothed sunspot number occurred during September 1989, according to the Sunspot Index Data Center. Therefore, the recent irradiance increasing trend should disappear during early 1990 and change into a decreasing trend if the observed irradiance variability is correlated more so with the 11-year sunspot cycle than the 22-year Hale cycle. The ERBE irradiance values are presented and compared with sunspot activity for the 1984 to 1989 period. The ERBE values are compared with those available from the Nimbus-7 and Solar Maximum Mission spacecraft experiments
Heat-transfer Measurements on a Blunt Spherical-segment Nose to a Mach Number of 15.1 and Flight Performance of the Rocket-propelled Model to a Mach Number of 17.8
Heat transfer measurements on blunt spherical segment nose and cylindrical body and flight test of rocket-propelled mode
A NASA initiative: Software engineering for reliable complex systems
The objective is the development of methods, technology, and skills that will enable NASA to cost-effectively specify, build, and manage reliable software which can evolve and be maintained over an extended period. The need for such software is rooted in the increasing integration of software and computing components into NASA systems. Current NASA Software Engineering expertise was applied toward some of the largest reliable systems including: shuttle launch; ground support; shuttle simulation; minor control; satellite tracking; and scientific data systems. Unfortunately, no theory exists for reliable complex software systems. NASA is seeking to fill this theoretical gap through a number of approaches. One such approach is to conduct research on theoretical foundations for managing complex software systems. It includes: communication models, new and modified paradigms, and life-cycle models. Another approach is research in the theoretical foundations for reliable software development and validation. It focuses upon formal specifications, programming languages, software engineering systems, software reuse, formal verification, and software safety. Further approaches involve benchmarking a NASA software environment, experimentation within the NASA context, evolution of present NASA methodology, and transfer of technology to the space station software support environment
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