In many occasions orthophotos in the background of GIS applications enrich their presentation. Often they serve for data capturing. Geometrically such images posses a defined, homogeneous geometry. One produces orthophotos since several decades with ever increasing demands and performance in quality and quantity. However, large-scale city orthophotos using standard algorithms and procedures typ...

Consider a convex polygon Vn with n sides, perimeter Pn, diameter Dn, area An, sum of distances between vertices Sn and widthWn. Minimizing or maximizing any of these quantities while fixing another defines ten pairs of extremal polygon problems (one of which usually has a trivial solution or no solution at all). We survey research on these problems, which uses geometrical reasoning increasingl...

This paper deals with the computational complexity, and in some cases undecidability, of several problems in nonlinear control. The objective is to compare the theoretical difficulty of solving such problems to the corresponding problems for linear systems. In particular, the problem of null-controllability for systems with saturations (of a “neural network” type) is mentioned, as well as probl...

Leighton and Rao use multicommodity flow results to design the first polynomial time approximation algorithms for well known NP-Hard optimization problems. Such problems include graph partitioning, crossing number, VLSI layout, and many more. Furthermore, Leighton and Rao are responsible for establishing the max-flow min-cut theorems on multicommodity flow problems, which lead to the algorithms...

PBL is a studying process that emphasizes how to enquire, understand and solve problems. Problem Base is a form of resource for PBL’s implementation and is indispensable to the overall practice of the latter. This article first sets about the two types of problems: disciplinary and conditional to collect problems from 6 aspects-teacher’s reflection, students, colleagues, teaching supervision an...

This paper deals with the computational complexity, and in some cases undecidability, of several problems in nonlinear control. The objective is to compare the theoretical difficulty of solving such problems to the corresponding problems for linear systems. In particular, the problem of null-controllability for systems with saturations (of a “neural network” type) is mentioned, as well as probl...

AS mentioned in various parts of this review, alcohol-related problems are not merely "alcoholism" and programmes focused on specific contexts may provide more encouraging results than a total preventive programme. Information is brought together in this section on four such contexts and it will be seen that, although there appear to be few well defined efforts to reduce particular health probl...