We show that any element of the identity component of the group of Cr diffeomorphisms Diffc(R )0 of the n-dimensional Euclidean space R n with compact support (1 5 r 5 ∞, r = n + 1) can be written as a product of two commutators. This statement holds for the interior Mn of a compact n-dimensional manifold which has a handle decomposition only with handles of indices not greater than (n − 1)/2. ...

PCI JOURNAL This paper presents the results of nonlinear fi nite element analyses conducted to model the behavior of L-shaped, precast, prestressed concrete spandrels constructed with open web reinforcement. The fi nite element model was calibrated using experimental results from recent tests of slender, L-shaped, precast, prestressed concrete spandrels. Detailed correlative studies between ana...

We define a new type of spectrum, called δ-approximate spectrum, of an element a in a complex unital Banach algebra A and show that the δ-approximate spectrum σ_δ (a) of a is compact. The relation between the δ-approximate spectrum and the usual spectrum is investigated. Also an analogue of the classical Gleason-Kahane-Zelazko theorem is established: For each ε>0, there is δ>0 such that if ϕ is...

In this paper, we propose a new compact quasi-fractal shaped microstrip antenna that consists of a hexagonal patch as the main radiator and a complementary stacked patch as the parasitic element. The overall surface of the proposed quasi-fractal patch is about 55% lower than the conventional hexagonal patch. Using of stacked technique, the gain reduction of compression technique is almost compe...