3,795 research outputs found
Finding central decompositions of p-groups
Polynomial-time algorithms are given to find a central decomposition of
maximum size for a finite p-group of class 2 and for a nilpotent Lie ring of
class 2. The algorithms use Las Vegas probabilistic routines to compute the
structure of finite *-rings and also the Las Vegas C-MeatAxe. When p is small,
the probabilistic methods can be replaced by deterministic polynomial-time
algorithms.
The methods introduce new group isomorphism invariants including new
characteristic subgroups.Comment: 28 page
Magnetic Tunnel Junction-Based On-Chip Microwave Phase and Spectrum Analyzer
A magnetic tunnel junction (MTJ)-based microwave detector is proposed and investigated. When the MTJ is excited by microwave magnetic fields, the relative angle between the free layer and pinned layer alternates, giving rise to an average resistance change. By measuring the average resistance change, the MTJ can be utilized as a microwave power sensor. Due to the nature of ferromagnetic resonance, the frequency of an incident microwave is directly determined. In addition, by integrating a mixer circuit, the MTJ-based microwave detector can also determine the relative phase between two microwave signals. Thus, the MTJbased microwave detector can be used as an on-chip microwave phase and spectrum analyzer
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On Visible Homelessness and the Micro-Aesthetics of Public Space
In this article, we investigate the circumstances that have produced the current municipal regulatory approach to homelessness in the City of Melbourne, Victoria, and the ways in which visibly homeless people are policed through a micro-aesthetics of their presence in public space, which involves the monitoring of their bodily demeanour and their physical possessions. Our study contributes to and draws from a range of debates, including studies of the governmental conjunction of poverty and crime, analysis of the co-implication of law and spatiality, research on the criminalisation of homelessness and homeless people, and the burgeoning criminological interest in the significance of the visual field for our understandings of crime and criminality. This article recounts how homelessness, public space and questions of aesthetics have recently coalesced in debates about the regulation of homelessness in the public space of Melbourne’s city centre. It approaches the issues through comparative consideration of genres of municipal management frameworks in other jurisdictions, detailed textual consideration of the Protocol on Homelessness in the City of Melbourne and an empirical study of visible homelessness in the public places of central Melbourne
Importance sampling method of correction for multiple testing in affected sib-pair linkage analysis
Using the Genetic Analysis Workshop 13 simulated data set, we compared the technique of importance sampling to several other methods designed to adjust p-values for multiple testing: the Bonferroni correction, the method proposed by Feingold et al., and naïve Monte Carlo simulation. We performed affected sib-pair linkage analysis for each of the 100 replicates for each of five binary traits and adjusted the derived p-values using each of the correction methods. The type I error rates for each correction method and the ability of each of the methods to detect loci known to influence trait values were compared. All of the methods considered were conservative with respect to type I error, especially the Bonferroni method. The ability of these methods to detect trait loci was also low. However, this may be partially due to a limitation inherent in our binary trait definitions
Molecular and atomic line surveys of galaxies I: the dense, star-forming phase as a beacon
We predict the space density of molecular gas reservoirs in the Universe, and
place a lower limit on the number counts of carbon monoxide (CO), hydrogen
cyanide (HCN) molecular and [CII] atomic emission lines in blind redshift
surveys in the submillimeter-centimeter spectral regime. Our model uses: (a)
recently available HCN Spectral Line Energy Distributions (SLEDs) of local
Luminous Infrared Galaxies (LIRGs, L_IR>10^11 L_sun), (b) a value for
epsilon=SFR/M_dense(H_2) provided by new developments in the study of star
formation feedback on the interstellar medium and (c) a model for the evolution
of the infrared luminosity density. Minimal 'emergent' CO SLEDs from the dense
gas reservoirs expected in all star-forming systems in the Universe are then
computed from the HCN SLEDs since warm, HCN-bright gas will necessarily be
CO-bright, with the dense star-forming gas phase setting an obvious minimum to
the total molecular gas mass of any star-forming galaxy. We include [CII] as
the most important of the far-infrared cooling lines. Optimal blind surveys
with the Atacama Large Millimeter Array (ALMA) could potentially detect very
distant (z~10-12) [CII] emitters in the >ULIRG galaxy class at a rate of ~0.1-1
per hour (although this prediction is strongly dependent on the star formation
and enrichment history at this early epoch), whereas the (high-frequency)
Square Kilometer Array (SKA) will be capable of blindly detecting z>3 low-J CO
emitters at a rate of ~40-70 per hour. The [CII] line holds special promise for
the detection of metal-poor systems with extensive reservoirs of CO-dark
molecular gas where detection rates with ALMA can reach up to 2-7 per hour in
Bands 4-6.Comment: 16 pages, 9 figures, accepted for publication in Ap
Ethics and the Public Administrator
This article provides an overview and analysis of the practical problems of developing and implementing a code of ethics for public administrators. The article addresses three key issues: (1) What are public ethics and where do they come from? (2) What are the central ethical issues facing public administrators? and (3) Are there practical tools and guidelines to assist public servants to be both ethical and effective public managers? The article concludes with a plea for consideration of ethical issues, and it presents five general ethical principles for public administrators
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