Let L be a field which is a Galois extension of the field K with Galois group G. Greither and Pareigis [GP87] showed that for many G there exist K-Hopf algebras H other than the group ring KG which make L into an H-Hopf Galois extension of K (or a Galois H∗object in the sense of Chase and Sweedler [CS69]). Using Galois descent they translated the problem of determining the Hopf Galois structure...

We introduce a notion of depth three tower C ⊆ B ⊆ A with depth two ring extension A|B being the case B = C . If A = End BC and B|C is a Frobenius extension with A|B|C depth three, then A|C is depth two. If A, B and C correspond to a tower G > H > K via group algebras over a base ring F , the depth three condition is the condition that K has normal closure KG contained in H . For a depth three ...

Programs compiled by Gambit, our Scheme compiler, achieve performance as much as twice that of the fastest available Scheme compilers. Gambit is easily ported, while retaining its high performance, through the use of a simple virtual machine (PVM). PVM allows a wide variety of machine-independent optimizations and it supports parallel computation based on the future construct. PVM conveys high-...

An analysis of the effect of orientation on the heat transfer in a scaled model pin fin heat sink utilized in Light Emitting Diode (LED) lighting has been carried out using numerical method. The present study involves natural convective heat transfer that takes place in particular heat sink. A pin fin type heat sink has been studied since they are widely used in LED lighting systems which in tu...

The tall building is the most dominating symbol of the cities and a human made marvel that defies gravity by reaching to clouds. The development of high strength concrete, higher grade steel, new construction techniques and advanced computational technique has resulted in the emergence of a new generation of tall structures that are flexible, low in damping, slender and light in weight. These t...

The objective of this study was to determine whether the 2004 USA Dewine-Kennedy Bill is congruent with Philip Morris' core policy principles for United States Food and Drug Administration (FDA) regulation of tobacco and what impact that would have on the public health. I compared the Dewine-Kennedy Bill with 1999 Philip Morris core policy principles for FDA regulation. Additional supporting da...

Aim The ecosystem functions and services of coral reefs are critical for coastal communities worldwide. Due to conservation resource limitation, species need be prioritized protect desirable properties biodiversity, such as functional diversity (FD), which has been associated with greater functioning but is difficult quantify directly. Selecting maximize phylogenetic (PD) shown indirectly captu...

In this paper, we will present an explicit construction of Harvey Friedman which to every finitely generated group G associates a 2-generator subgroup KG 6 Sym(N) such that G embeds into KG and such that if G ∼= H, then KG = KH .

1 Department of Geoscience, University of Calgary, Calgary, Alberta, Canada T3B 4Y3 ( [email protected]; [email protected]) 2 Institute of Stochastics, Ulm University, Helmholtzstrasse 18, D-89069, Ulm, Germany ([email protected]; [email protected]) 3 Boehringer Ingelheim Pharma GmbH & Co. KG, Medical Data Services/Biostatistics, 88397 Biberach a. d. R., Germany (frank.fleisc...

Let K be a field of positive characteristic p and KG the group algebra of a group G. It is known that if KG is Lie nilpotent then its upper (or lower) Lie nilpotency index is at most |G| + 1, where |G| is the order of the commutator subgroup. The class of groups G for which these indices are maximal or almost maximal have already been determined. Here we determine G for which upper (or lower) L...