The queen graph coloring problem consists in covering a n × n chessboard with n queens, so that two queens of the same color cannot attack each other. When the size, n, of the chessboard is a multiple of 2 or 3, it is hard to color the queen graph with only n colors. We have developed an exact algorithm which is able to solve exhaustively this problem for dimensions up to n = 12 and find one so...

This paper provides analysis to a generalized version of the coupon collector problem, in which the collector gets d coupons each run and he chooses the one that he has the least so far. In the asymptotic case when the number of coupons n goes to infinity, we show that on average n log n d + n d (m−1) log log n+O(mn) runs are needed to collect m sets of coupons. An efficient exact algorithm is ...

Analysis of genome rearrangements allows to compare molecular data from species that diverged a very long time ago. Results and complexities are tightly related to the type of data and genome-level mutations considered. For sorted and signed data, Hannenhalli and Pevzner (HP) developed the rst polynomial algorithm in the eld. This algorithm solves the problem of sorting by reversals. In this pa...

This paper explores a single-item capacitated lot sizing problem with minimum order quantity, which plays the role of minor set-up cost. We work out the necessary and sufficient solvability conditions and apply the general dynamic programming technique to develop an O(T ) exact algorithm that is based on the concept of minimal sub-problems. An investigation of the properties of the optimal solu...

From 13.03. to 16.03.2007, the Dagstuhl Seminar 07112 Cutting, Packing, Layout and Space Allocation was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of semi...

In this paper we worked upon on optimal wiring on rectangular structure. Here we are given a rectangle partitioned into smaller rectangles by axis-parallel line segments. Find a subset of the segments such that the resulting structure from these segments is connected and it touches every smaller rectangle. Here we reduce the problem of exact cover by 3-sets (X3C), which is known to be NP-comple...

Exact loop-variables formulation of pure gauge lattice QCD3 is derived from the Wilson version of the model. The observation is made that the resulting model is two-dimensional. This significant feature is shown to be a unique property of the gauge field. The model is defined on the infinite genus surface which covers regularly the original three-dimensional lattice. Similar transformation appl...

The paper estimates the Chernoff rate for the efficiency of quantum hypothesis testing. For both joint and separable measurements, approximate bounds for the rate are given if both states are mixed and exact expressions are derived if at least one of the states is pure. The efficiency of tests with separable measurements is found to be close to the efficiency of tests with joint measurements. T...

We construct a non-free but א1-separable, torsion-free abelian group G with a pure free subgroup B such that all subgroups of G disjoint from B are free and such that G/B is divisible. This answers a question of Irwin and shows that a theorem of Blass and Irwin cannot be strengthened so as to give an exact analog for torsion-free groups of a result proved for p-groups by Benabdallah and Irwin.

We showed several years ago that the density operator of Markovian open systems can be diagonalized continuously in time. The resulting pure state jump processes correspond to quantum trajectories proposed in recent quantum optics calculations or, at fundamental level, to exact consistent histories. The quantum state of an open quantum system — actually a subsystem of a closed one — cannot be d...