Reducing energy consumption has become a pressing issue in cluster computing systems not only for minimizing electricity cost, but also for improving system reliability. Therefore, it is highly desirable to design energy-efficient scheduling algorithms for applications running on clusters. In this paper, we address the problem of non-preemptively scheduling mixed tasks on power-aware clusters. ...

1 Regular Languages and Logic 3 1.1 Regular Languages and Finite Automata . . . . . . . . . 3 1.2 First-Orderand Monadic-Second-Order-Logic . . . . . 5 2 Other Equivalent Representations 9 2.1 Two-way Finite Automata . . . . . . . . . . . . . . . . . 9 2.2 First Order Logic with Transitive Closure . . . . . . . . 13 3 Two-Way Multihead Automata 17 4 k-ary Transitive Closure 26 5 Tree Walking Au...

In Descriptive Complexity, we investigate the use of logics to characterize computational complexity classes. Since 1974, when Fagin proved that the class NP is captured by existential second-order logic, considered the first result in this area, other relations between logics and complexity classes have been established. Well-known results usually involve first-order logic and its extensions, ...

This paper studies expressivity bounds for extensions of rst-order logic with counting and unary quantiiers in the presence of relations of large degree. There are several motivations for this work. First, it is known that rst-order logic with counting quantiiers captures uniform TC 0 over ordered structures. Thus, proving expressivity bounds for rst-order with counting can be seen as an attemp...

Title of dissertation: MODEL THEORY AND COMPLEXITY THEORY Walid Gomaa Doctor of Philosophy, 2007 Dissertation directed by: Professor William Gasarch Department of Computer Science and Professor David Kueker Department of Mathematics Descriptive complexity theory is a branch of complexity theory that views the hardness of a problem in terms of the complexity of expressing it in some logical form...

Descriptive k-Means natomiast ekstrakcj˛ e fraz cz˛ estych, frazy nominalne oraz grupowanie przy pomocy algorytmu k-Means (k-´ srednich). W pracy przedstawiono eksperymenty obliczeniowe dla obu algorytmów. Wyniki eksperymentów porównuj ˛ a jako´s´c grupowania (rozumian ˛ a jako sposób odtworzenia znanego przydziału dokumentów do grup) przy u˙ zyciu Lingo oraz Descriptive k-Means, z ich najbli˙ ...

Descriptive document clustering aims to automatically discover groups of semantically related documents and to assign a meaningful label to characterise the content of each cluster. In this paper, we present a descriptive clustering approach that employs a distributed representation model, namely the paragraph vector model, to capture semantic similarities between documents and phrases. The pro...

Let 2N be the class of families of problems solvable by families of two-way nondeterministic finite automata of polynomial size. We characterize 2N in terms of families of formulas of transitive-closure logic. These formulas apply the transitive-closure operator on a quantifier-free disjunctive normal form of first-order logic with successor and constants, where (i) apart from two special varia...

We describe dynamic voltage scaling (DVS) algorithms for real-time systems with both periodic and aperiodic tasks. Although many DVS algorithms have been developed for real-time systems with periodic tasks, none of them can be used for the system with both periodic and aperiodic tasks because of arbitrary temporal behaviors of aperiodic tasks. We propose an off-line DVS algorithm and online DVS...

The Ehrenfeucht-Fraı̈ssé method for first-order logic and further logics relevant in descriptive complexity has been quite successful. However, for key problems such as P 6= NP or NP 6= co-NP no progress has been achieved using it. We show that for these problems we can not get the board for the corresponding Ehrenfeucht-Fraı̈ssé game in polynomial output time, even if we allow probabilistic meth...