388,762 research outputs found
Perfect colourings of isonemal fabrics by thin striping
Perfect colouring of isonemal fabrics by thin striping of warp and weft and
the closely related topic of isonemal prefabrics that fall apart are
reconsidered and their relation further explored. The catalogue of isonemal
prefabrics that fall apart is extended to order 20 for those of even genus.Comment: 25 pages, 20 figure
The Great War Then and Now: Reflections on America’s Declaration of War
This short essay explores the many impacts of the 1917 U.S. entry to World War I on the author\u27s hometown of Pennington, NJ, and the reaction of its residents at the time
Extreme Sensitivity of the YORP Effect to Small-Scale Topography
Radiation recoil (YORP) torques are shown to be extremely sensitive to
small-scale surface topography. Starting from simulated objects representative
of the near-Earth object population, random realizations of three types of
small-scale topography are added: Gaussian surface fluctuations, craters, and
boulders. For each, the resulting expected relative errors in the spin and
obliquity components of the YORP torque are computed. Gaussian power produces
errors of order 100% if observations constrain the surface to a spherical
harmonic order l < 10. A single crater with diameter roughly half the object's
mean radius, placed at random locations, results in errors of several tens of
percent. Boulders create torque errors roughly 3 times larger than do craters
of the same diameter. A single boulder comparable to Yoshinodai on 25143
Itokawa, moved by as little as twice its own diameter, can alter the magnitude
of the torque by factors of several, and change the sign of its spin component
at all obliquities. A YORP torque prediction derived from groundbased data can
be expected to be in error by of order 100% due to unresolved topography. Small
surface changes caused by slow spin-up or spin-down may have significant
stochastic effects on the spin evolution of small bodies. For rotation periods
between roughly 2 and 10 hours, these unpredictable changes may reverse the
sign of the YORP torque. Objects in this spin regime may random-walk up and
down in spin rate before the rubble-pile limit is exceeded and fissioning or
loss of surface objects occurs. Similar behavior may be expected at rotation
rates approaching the limiting values for tensile-strength dominated objects.Comment: Icarus, accepted. 18 pp., 15 fi
Emerging Alternatives to Mutual Funds: Unit Investment Trusts and Other Fixed Portfolio Investment Vehicles
Thomas Harman offers a comprehensive analysis of the Unit Investment Trust. First, he defines the trust, examining the mechanics and participants associated with it. He then traces the development of the trust since its inception as a  fixed trust.  Next he discusses the regulation of the trust by the Securites Acts of 1933 and 1940. Finally, he compares the unit investment trust with other investment vehicles
Racing to War: Arms Competitions, Military Spending, and the Tendency of Nations to Engage in Armed Conflict
An essay exploring the relationship between arms acquisition, military spending, and the tendency of nations to engage in war
Mandating Disclosure in Municipal Securities Issues: Proposed New York Legislation
This article surveys the existing mechanisims (primarily stemming from federal law) resulting in financial disclosure in connection with the offering and sale to the public of securities of New York municipal issuers. It also describes and compares alternative models for regimes of municipal issuer financial disclosure, such as the MFOA Guidelines, the federal Williams Bill and Industrial Bond Act and New York\u27s Disclosure Proposals. The article ultimately concludes that although the isolated purpose of protecting investors in a municipal securities market that is largely national could most effectively be pursued by the imposition of uniform disclosure requirements through federal law, the Disclosure Proposals are not demonstrably inadequate to this purpose, and the intrustion into the affiars of the state and local governments of New York that would accompany the federal law approach makes the enactment of the Disclosure Proposals a more attractive alternative
- …
