The Closest Substring Problem is one of the most important problems in the field of computational biology. It is stated as follows: given a set of t sequences s1; s2; : : : st over an alphabet , and two integers k; d with d k, can one find a string s of length k and, for all i = 1; 2; : : : ; t, substrings oi of si, all of length k, such that d(s; oi) d (for all i = 1; 2; : : : ; t)? (here, d(:...

What makes a problem hard to compute, and how does one categorize problems that accurately captures this notion of hardness? Computer science has traditionally approached this issue with two classification schemas: resource-bounded complexity classes (deterministic or nondeterministic time and space bound computations) and bounded reducibilities (≤m and ≤ T reductions). We show that neither of ...

Consider a decision problem that cannot be 1 ? approximated by circuits of a given size in the sense that any such circuit fails to give the correct answer on at least a fraction of instances. We show that for any such problem there is a speciic \hard-core" set of inputs which is at least a fraction of all inputs and on which no circuit of a slightly smaller size can get even a small advantage ...

water quality in each area, indicates the impact of geology, climate and anthropogenic pollutants. monitoring of water quality in most cases result in complex data which shows the perfect act of water resources, so they need appropriate method for analyzing. in this study hydro-chemical evaluation of hiv basin which located in west of hashtgerd have been done. to measure the concentration of ma...

In this paper we study NP-hard variable-weighted satisfiability optimization problems for the class 2-CNF providing worst-case upper time bounds holding for arbitrary real-valued weights. Moreover, we consider the monotone dual class consisting of clause sets where all variables occur at most twice. We show that weighted SAT, XSAT and NAESAT optimization problems for this class are polynomial t...

1 What are intelligent technologies Many practical problems, e.g., many engineering design problems, can be solved by known (routine) techniques. For many of these problems, these techniques have been incorporated into software packages, so the solution to these problems can be (largely) automated. However, there are still many other problems for which no routine techniques are known. For examp...