Luca Trevisan [1] presented an approximation algorithm for Max Cut based on spectral partitioning techniques. He proved that the algorithm has an approximation ratio of at least 0.531. We improve this bound up to 0.6142. We also define and extend this result for the more general Maximum Colored Cut problem.

in the open-pit mining, one of the first decisions that must be made in production planning stage, after completing the design of final pit limits, is determining of the processing plant cut-off grade. since this grade has an essential effect on operations, choosing the optimum cut-off grade is of considerable importance. different goals may be used for determining optimum cut-off grade. one of...

max (k, n − k)-cut (resp., min (k, n − k)-cut) is a constrained version of max-cut (resp., min-cut) where one has to find a bipartition of the vertex set into two subsets with respectively k and n − k vertices (n being the total number of vertices of the input graph) which maximizes (resp., minimizes) the number of edges going from one subset to the other. In this paper, we investigate the para...

Field-Programmable Gate Arrays (FPGAs) are flexible and reusable circuits that can be easily reconfigured by the designer. One of the steps involved in the logic design with FPGA circuits is placement. In this step, the logic functions are assigned to specific cells of the circuit. In this paper we present a placement algorithm for FPGA circuits. In traditional min-cut based placement algorithm...

The well-known Max Cut problem asks for the largest bipartite subgraph of a graph G. This problem has been the subject of extensive research, both from the algorithmic perspective in computer science and the extremal perspective in combinatorics. Let n be the number of vertices and e be the number edges of G and let b(G) denote the size of the largest bipartite subgraph of G. The extremal part ...

We analyze the addition of a simple local improvement step to various known ran-domized approximation algorithms. Let ' 0:87856 denote the best approximation ratio currently known for the Max Cut problem on general graphs GW95]. We consider a semideenite relaxation of the Max Cut problem, round it using the random hyperplane rounding technique of ((GW95]), and then add a local improvement step....

This paper studies the existence of eecient (small size) ampliiers for proving explicit inaproximability results for bounded degree and bounded occurrence combinatorial optimization problems, and gives an explicit construction for such ampliiers. We use this construction to improve the currently best known approximation lower bounds for bounded occurrence instances of linear equations mod 2, an...