82,252 research outputs found
Algebras, dialgebras, and polynomial identities
This is a survey of some recent developments in the theory of associative and
nonassociative dialgebras, with an emphasis on polynomial identities and
multilinear operations. We discuss associative, Lie, Jordan, and alternative
algebras, and the corresponding dialgebras; the KP algorithm for converting
identities for algebras into identities for dialgebras; the BSO algorithm for
converting operations in algebras into operations in dialgebras; Lie and Jordan
triple systems, and the corresponding disystems; and a noncommutative version
of Lie triple systems based on the trilinear operation abc-bca. The paper
concludes with a conjecture relating the KP and BSO algorithms, and some
suggestions for further research. Most of the original results are joint work
with Raul Felipe, Luiz A. Peresi, and Juana Sanchez-Ortega.Comment: 32 page
Who\u27s Flaithbhertach Macloingry?
In the November 1989 Word Ways George H. Scheetz presented a list of 51 words ending in -gry. His fascinating article piqued my interest and I immediately set out to find some additions to his list
The precession of eccentric discs in close binaries
We consider the precession rates of eccentric discs in close binaries, and
compare theoretical predictions with the results of numerical disc simulations
and with observed superhump periods. A simple dynamical model for precession is
found to be inadequate. For mass ratios less than approximately 1/4 a linear
dynamical model does provide an upper limit for disc precession rates. Theory
suggests that pressure forces have a significant retrograde impact upon the
precession rate (Lubow 1992). We find that the disc precession rates for three
systems with accurately known mass ratios are significantly slower than
predicted by the dynamical theory, and we attribute the difference to pressure
forces. By assuming that pressure forces of similar magnitude occur in all
superhumping systems, we obtain an improved fit to superhump observations.Comment: 6 pages to appear in MNRAS (accepted
Modelling human control behaviour with a Markov-chain switched bank of control laws
A probabilistic model of human control behaviour is described. It assumes that human behaviour can be represented by switching among a number of relatively simple behaviours. The model structure is closely related to the Hidden Markov Models (HMMs) commonly used for speech recognition. An HMM with context-dependent transition functions switching between linear control laws is identified from experimental data. The applicability of the approach is demonstrated in a pitch control task for a simplified helicopter model
Grappling with “Solicitation”: The Need For Statutory Reform in North Carolina after Lawrence v. Texas
Teresa Pope was charged with solicitation of the crime against nature for offering oral sex for money to two undercover police officers.5 Solicitation is an inchoate offense-like attempt or conspiracy-that relies on the criminality of the underlying conduct. 6 Although oral sex by itself cannot be criminalized post-Lawrence, the North Carolina Court of Appeals held in State v. Pope that the charge of solicitation of the crime against nature survived Lawrence by virtue of an exception in that decision allowing criminalization of prostitution. 10 In State v. Richardson, the Supreme Court of North Carolina construed this statute to apply only to vaginal, heterosexual sex.11 Consistent with the canon that criminal laws are to be interpreted narrowly, the court explained that [i]f the legislature wishes to include within [the prostitution statute] other sexual acts, such as cunnilingus, fellatio, masturbation, buggery or sodomy, it should do so with specificity
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