Combining linear programming approach with the Plotkin-Johnson argument for constant weight codes, we derive upper bounds on the size of codes of length n and minimum distance d = (n j)=2, 0 < j < n 1=3 . For j = o(n 1=3 ) these bounds practically coincide (are slightly better) with the Tietav ainen bound. For xed j and j proportional to n 1=3 , j < n 1=3 (2=9) lnn, it improves on the earlier...

Minimum sum-of-squares clustering (MSSC) is a widely studied task and numerous approximate as well as a number of exact algorithms have been developed for it. Recently the interest of integrating prior knowledge in data mining has been shown, and much attention has gone into incorporating user constraints into clustering algorithms in a generic way. Exact methods for MSSC using integer linear p...

Disorders caused by deliberate sabotage and terrorist attacks have always been considered as a major threat by the governments. Hence, identifying and planning for strengthening of critical facilities have become a priority for more security and safety. This paper presents a bi-level formulation of the rinterdiction median problemwith fortification for critical hierarchical facilities. In the d...

Most traditional routing problems assume perfect operability of all arcs and nodes. However, when independent arc failure probabilities exist, a secondary objective must be present to retain some measure of expected functionality, introducing nonlinear, nonconvex constraints. We examine the Robust Two-Path Problem, which seeks to establish two paths between a source and destination node wherein...

We introduce new penalties, called valid integer polytope (VIP) penalties, that tighten the bound of an integer-linear program during branch-and-bound enumeration. Early commercial codes for branch and bound commonly employed penalties developed from the dual simplicial lower bound on the cost of restricting fractional integer variables to proximate integral values. VIP penalties extend and tig...

In this paper, we consider the so-called balanced bi-clustering problem for n entities in a suitable space where the number of entities in each cluster is bounded. A special case of the balanced bi-clustering, where the number of entities in each cluster is fixed, is discussed. We present several algorithms, including deterministic and heuristic to attack these problems. In particular, a novel ...

The control problem and Dynamic programming is a powerful tool in economics and management. We review the dynamic programming problem from its beginning up to its present stages. A problem which was involved in physics and mathematics in I 7” century led to a branch of mathematics called calculus of variation which was used in economic, and management at the end of the first quarter of the 20” ...

In this paper, bi-level programming is proposed for designing a competitive supply chain network. A two-stage stochastic programming approach has been developed for a multi-product supply chain comprising a capacitated supplier, several distribution centers, retailers and some resellers in the market. The proposed model considers demand’s uncertainty and disruption in distribution centers and t...

This paper addresses a bi-criteria two-machine flowshop scheduling problem when the learning effect is present. The objective is to find a sequence that minimizes a weighted sum of the total completion time and the maximum tardiness. In this article, a branch-and-bound method, incorporating several dominance properties and a lower bound, is presented to search for the exact solution for small j...

We present a column-generation model and branch-and-price-and-cut algorithm for origin-destination integer multicommodity flow problems. The origin-destination integer multicommodity flow problem is a constrained version of the linear multicommodity flow problem in which flow of a commodity (defined in this case by an origin-destination pair) may use only one path from origin to destination. Br...