In this paper, we classify all generalized quadrangles weakly embedded of degree 2 in projective space. More exactly, given a (possibly infinite) generalized quadrangle Γ = (P,L, I ) and a map π from P (respectively L) to the set of points (respectively lines) of a projective space PG(V ), V a vector space over some skew field (not necessarily finite-dimensional), such that: (i) π is injective ...

seen tremendous advances in our ability to produce images of human brain function. Applications of functional brain imaging extend from improving our understanding of the basic mechanisms of cognitive processes to better characterization of pathologies that impair normal function. Magnetoencephalography (MEG) and electroencephalography (EEG) (MEG/EEG) localize neural electrical activity using n...

We discuss the axioms for vertex algebras and their modules, using formal calculus. Following certain standard treatments, we take the Jacobi identity as our main axiom and we recall weak commutativity and weak associativity. We derive a third, companion property that we call “weak skew-associativity.” This third property in some sense completes an S3-symmetry of the axioms, which is related to...

â a model is developed for separation of multicomponent gas mixtures in a countercurrent hollow fiber membrane module. while the model’s solution in countercurrent module usually involves in a time consuming iterative procedure, a proper initial guess is proposed for beginning the calculation and a simple procedure is introduced for correcting the guesses, hereby the cpu time is decreased ess...

We define and study strong diagonalization and compare it to weak diagonalization, implicit in [7]. Kozen’s result in [7] shows that virtually every separation can be recast as weak diagonalization. We show that there are classes of languages which can not be separated by strong diagonalization and provide evidence that strong diagonalization does not relativize. We also define two kinds of ind...

In the title compound, C(16)H(16)O(2)S, the central propenone group is almost planar (r.m.s. deviation = 0.009 Å) and subtends dihedral angles of 8.55 (8) and 16.22 (8)° to the 2-meth-oxy-phenyl and 2,5-dimethyl-thio-phene residues, respectively. The dihedral angle between the ring systems is 23.47 (5)°. In the crystal, mol-ecules are linked by weak C-H⋯π inter-actions and aromatic π-π stacking...

We address the problem of blind source separation in the underdetermined mixture case. Two statistical tests are proposed to reduce the number of empirical parameters involved in standard sparsenessbased underdetermined blind source separation (UBSS) methods. The first test performs multisource selection of the suitable time-frequency points for source recovery and is full automatic. The second...

A constrained iterative method for harmonic source parameter estimation is proposed based on an EM algorithm with an intent for harmonic source separation. The problem of coinciding partials and interference among them in general is mitigated by the constraints on the “weak” partials on the stronger ones of the same harmonic source. A useful scheme to determine the weakness of a partial is prop...

Given a finite point set P ⊂ R, we call a multiset A a one-sided weak ε-approximant for P (with respect to convex sets), if |P ∩ C|/|P | − |A ∩C|/|A| ≤ ε for every convex set C. We show that, in contrast with the usual (two-sided) weak ε-approximants, for every set P ⊂ R there exists a one-sided weak ε-approximant of size bounded by a function of ε and d.

During asymmetric cell division, cytoplasmic components are segregated to opposite sides of the cell. We discuss how the observed segregation can be achieved by a position-dependent phase separation mechanism controlled by a protein concentration gradient. We show that effects of even a weak gradient can be amplified by the phase transition to achieve strong segregation. We compare our theory t...