This is a pedagogical and (almost) self-contained introduction into the Theorem of Groenewold and van Howe, which states that a naive transcription of Dirac’s quantisation rules cannot work. Some related issues in quantisation theory are also discussed. First-class constrained systems a briefly described in a slightly more ‘global’ fashion.1

Background: Different modalities have been tried in order totreat stable vitiligo. Culturing melanocytes is time consumingand expensive. Therefore, new methods using autologousmelanocytes are sought. We aimed to compare the mixed nonculturedautologous melanocytes of the outer root sheath andthe bulge area of hair follicle transplantation plus dermabrasionwith dermabrasion alone in stable genera...

The digital image processing refers to processing of two dimensional images by digital computer. The image restoration is the reconstruction process applied to the degraded images. The removal of noise from images can be done by filters. New techniques are involved in the field of restoration other than filters. Nonlocal Image representation has shown great potential in various low-level vision...

In boreal ecosystems, wildfire severity (i.e., the extent of fire-related tree mortality) is affected by environmental conditions and fire intensity. A burned area usually includes tree patches that partially or entirely escaped fire. There are two types of post-fire residual patches: (1) patches that only escaped the last fire; and (2) patches with lower fire susceptibility, also called fire r...

Suppose that A ∈ RN×N is symmetric positive semidefinite with rank K ≤ N . Our goal is to decompose A into K rank-one matrices ∑K k=1 gkg T k where the modes {gk} K k=1 are required to be as sparse as possible. In contrast to eigen decomposition, these sparse modes are not required to be orthogonal. Such a problem arises in random field parametrization where A is the covariance function and is ...

Increased recognition of the disproportionately large contribution of newborn health to global child survival has fuelled efforts to address neonatal mortality in resource-limited settings. Stillbirths have not been as well studied despite the fact that more than 3 million stillbirths occur annually, a disease burden that approaches that of postnatal deaths. The poorest countries have the highe...

Cracks on concrete surface are typically clear warning signs of a potential threat to the integrity and serviceability structure. The techniques based image processing can effectively detect cracks from images. These techniques, however, generally susceptible user-driven heuristic thresholds extraneous distractors. Inspired by recent success artificial intelligence, deep learning automated crac...

CAD systems are usually based on a tensor product representation of free form surfaces. In this case, trimmed patches are used for modeling non rectangular zones. Trimmed patches provide a reasonable solution for the representation of general topologies, provided that the gap between equivalent trimming curves in the euclidean space is small enough. Several commercial CAD systems, however, repr...

A hexagonal patch is a plane graph in which inner faces have length 6, inner vertices have degree 3, and boundary vertices have degree 2 or 3. We consider the following counting problem: given a sequence of twos and threes, how many hexagonal patches exist with this degree sequence along the outer face? This problem is motivated by the study of benzenoid hydrocarbons and fullerenes in computati...

The new Allen Center for Business Activities is nearing completion between the Cohen House Faculty Club and the old wing of Baker College. The million dollar building was a gift f rom Mr. and Mrs. Herbert Allen. The center, to be finished in June, will house treasurer, cashier, accounting, campus business, and development offices. In addition, the building will be a temporary home for offices a...