1. Denote by S, an arbitrary latin square with n elements {a 1 , a 2 , . . . , a„ } . A row and column of this square, intersecting on the main diagonal (i .e . diagonal beginning at the left lower corner) will be called corresponding . After striking out n c arbitrary rows and corresponding columns, a square T, with c x c entries remains . Such a square will be called a principal minor. It is ...

A combinatorial design problem is considered which can be modelled as a constraint satisfaction problem in several diierent ways. The models all have a large number of symmetries which cause diiculties when searching for solutions. Diierent approaches to reducing the symmetry are discussed: remodelling the problem ; adding constraints to the model at the outset; and adding constraints during se...

We give a generalization of a result of Myerson on the asymptotic behavior of norms of certain Gaussian periods. The proof exploits properties of the Mahler measure of a trinomial.

We consider a generalization of the maximum flow problem in which the amounts of flow entering and leaving an arc are linearly related. More precisely, if x(e) units of flow enter an arc e, x(e)γ(e) units arrive at the other end. For instance, nodes of the graph can correspond to different currencies, with the multipliers being the exchange rates. We require conservation of flow at every node e...

For any integer r > 2, define a sequence of numbers {c (r) k }k=0,1,..., independent of the parameter n, by n

the capacitated vehicle routing problem (cvrp) is a well-known combinatorial optimization problem that holds a central place in logistics management. the vehicle routing is an applied task in the industrial transportation for which an optimal solution will lead us to better services, save more time and ultimately increase in customer satisfaction. this problem is classified into np-hard problem...

scheduling for job shop is very important in both fields of production management and combinatorial op-timization. however, it is quite difficult to achieve an optimal solution to this problem with traditional opti-mization approaches owing to the high computational complexity. the combination of several optimization criteria induces additional complexity and new problems. in this paper, we pro...

In this paper we address the problem of reassembly of images from a collection of their fragments. The image reassembly problem is formulated as a combinatorial optimization problem and image assembly is then done by finding an optimal ordering of fragments. We present implementation results showing that images can be reconstructed with high accuracy even when there are thousands of fragments a...

The outputs of R&D, such as new research findings and new products and services, are generated with the aid of specialized problem-solving processes. These processes are somewhat arcane and have been largely ignored in studies of technical change. However, their improvement can significantly affect the kinds of research problems that can be addressed, the efficiency and speed with which R&D can...