The research presented in this paper is situated in the framework of constraint databases that was introduced by Kanellakis, Kuper, and Revesz in their seminal paper of 1990. In this area, databases and query languages are deened using real polynomial constraints. As a consequence of a classical result by Tarski, rst-order queries in the constraint database model are eeectively computable, and ...

Abstract When we have a digital image which contains some objects and a ruler, we know the size of objects by rough estimate. Since measuring the object size in the digital image is usually manual, we developed the detection method of scale interval on a ruler. In our method we transfer digital image into frequency space using two-dimensional discreet fourier transformation, a specific frequenc...

This paper relates democracy, public and private international capital flows, and odious debt. Democracy commits a ruler to pass borrowed funds on to the private sector which builds the country’s international collateral, and the consequent rise in the credit ceiling is a Pareto-improvement up to a point because the ruler can appropriate a smaller share of rising loan. However, the ruler may st...

Geometric Algebra is a very general mathematical system providing simultaneously a geometrification of algebra, and also an algebrification of geometry. As an example, we present a specific Geometric Algebra, that we call Compass Ruler Algebra, which is very well suited to compute similar to working with compass and ruler. Geometric objects such as circles and lines as well as geometric operati...

A Golomb ruler with m marks can be defined as a set of m distinct integers such that the differences between them are all distinct. An optimal Golomb ruler minimizes the value of the largest mark. The Golomb ruler problem is highly combinatorial and difficult to solve efficiently even for small sizes. Golomb rulers and related problems play an important role in, e.g., radio communication, VLSI ...

The Golomb ruler problem has been proposed as a challenging constraint satisfaction problem. We consider a large number of di erent models of this problem, both binary and non-binary. The problem can be modelled using quaternary constraints, but in practice using a set of auxiliary variables and ternary constraints gives better results. A binary encoding of the problem gives a smaller search tr...

1 Laboratory of Biochemistry, Scientific Affairs Department, APIVITA S.A., Athens, Greece, 2 Laboratory of Molecular Biology, Department of Biotechnology, School of Food, Biotechnology and Development, Agricultural University of Athens, Athens, Greece, 3 Fitoplanton Marino, Cádiz, Spain, 4 Laboratory of Enzyme Technology, Department of Biotechnology, School of Food, Biotechnology and Developmen...