STOC

Let A be the problem of minimizing c₁x₁+...+c_nx_n subject to certain constraints on x=(x₁,...,x_n), and let B be the problem of minimizing (a₀+a₁x₁+...+a_nx_n)/(b₀+b₁x₁+...+b_nx_n) subject to the same constraints, assuming the denominator is always positive. ...

we consider optimization problems on complete graphs with edge weights chosen from identical but independent normal distributions. We show some very general techniques for obtaining upper and lower bounds on the asymptotic behavior of these problems. ...

This paper describes a data structure which is useful for representing linear lists when the pattern of accesses to a list exhibits a (perhaps time-varying) locality of reference. The structure has many of the properties of the representation proposed ...

A general model for data compression is presented which includes most data compression systems in the literature as special cases. All macro schemes are based on the principle of finding redundant strings or patterns and replacing them by pointers to a ...

We investigate the problem of finding a homeomorphic image of a “pattern” graph H in a larger input graph G. We view this problem as finding specified sets of edge disjoint or node disjoint paths in G. Our main result is a linear time algorithm to ...

Tarjan has given an algorithm for deciding isomorphism of two groups of order n (given as multiplication tables) which runs in O(n^{(log₂n+O(1)}) steps where n is the order of the groups. Tarjan uses the fact that a group of n is generated by log n ...

In this paper we consider the question of how much space is needed to represent a set. Given a finite universe U and some subset V (called the vocabulary), an exact membership tester is a procedure that for each element s in U determines if s is in V. ...

This extended abstract is a condensed version of the results presented in two technical reports ([16] and [13]). In [16] a systematic treatment of the relationships between parallel rewriting systems (top-down tree transducer, ETOL system) and two-way ...

In this paper, we show that two widely different notions of program equivalence coincide for the language of recursive definitions with simplification rules. The first one is the now classical equivalence for fixed-point semantics. The other one is ...

A classical problem in concurrent program control is to provide a mechanism whereby several processes running concurrently can gain exclusive control of a resource. For each process, the section of its program in which it accesses the resource is called ...

A number of different models of synchronous, unbounded parallel computers have appeared in recent literature. Without exception, running time on these models has been shown to be polynomially related to the classical space complexity measure. The ...

Denotational semantics was introduced by Strachey as a means of defining semantics of programming languages. It's mathematical foundation was justified by Scott [14] in 1969 when he introduced continuous lattices to model data types and showed how to ...

When studying parallel computation and synchronization one is faced with the problem of modeling the simultaneous execution of processes. Although there has been a multitude of formal means for representing such problems [2, 6, 9, 10, 13, 14, 15], ...

A model of computation based on random access machines operating in parallel and sharing a common memory is presented. The computational power of this model is related to that of traditional models. In particular, deterministic parallel RAM's can accept ...

This paper extends our earlier work on abstract data types by providing an algebraic treatment of parametrized data types (e.g., sets-of-(), stacks-of-(), etc.), as well as answering a number of questions on the power and limitations of algebraic ...

The algorithm of the title is presented. It runs in time bounded by a polynomial in the number of the edges of the graph.

A sequence of monotone switching functions f_n:{0,1}ⁿ →{0,1}ⁿ is constructed, such that the monotone complexity of f_n grows faster than O(n^2-ε) for any ε>O. Previously the best lower bounds of this nature were several O(n^3/2) bounds due to Pratt, ...

This paper represents a continuation of work in [LBI] and [LB2] directed toward the development of a unified, relative model for complexity theory. The earlier papers establish a simple, natural and fairly general model, and demonstrated its ...

Fast computation of polynomials of 1 variable in the fields R and C of real and complex numbers is considered. The optimal schemes of computation with preconditioning (that is, the schemes involving the minimal number of arithmetic operations without ...

A large class of multiplication problems in arithmetic complexity can be viewed as the simultaneous evaluation of a set of bilinear forms. This class includes the multiplication of matrices, polynomials, quaternions, Cayley and complex numbers. ...

A minimum edge coloring of a bipartite graph is a partition of the edges into Δ matchings, where Δ is the maximum degree in the graph. Coloring algorithms are presented that use time O(min(¦E¦ Δ log n, ¦E¦ @@@@n log n, n²log Δ)) and space O(nΔ). This ...

We prove that any multivariate polynomial P of degree d that can be computed with C(P) multiplications-divisions can be computed in O(log d.log C(P)) parallel steps and O(log d) parallel multiplicative steps.

Recent research has investigated time-space tradeoffs for register allocation strategies of certain fixed sets of expressions. This paper is concerned with the time-space tradeoff for register allocation strategies of any set of expressions which ...

Systems of nonlinear equations of the form D: Ay = σ.(x), where A is an m×n matrix of rational constants and y = (Y₁,...,y_n), σ(x) = (σ₁(x),..., σ_m (x)) are column vectors are considered. Each σ_i(x) is of the form r_i(x) or @@@@r_i(x)@@@@, where r_i(x) is ...

The problem of deciding whether a given propositional formula in conjunctive normal form is satisfiable has been widely studied. I t is known that, when restricted to formulas having only two literals per clause, this problem has an efficient (...

We consider the problem of identifying an unknown value xε{1,2,...,n} using only comparisons of x to constants when as many as E of 'the comparisons may receive erroneous answers. For a continuous analogue of this problem we show that there is a unique ...

A new lower bound on the computational complexity of the theory of real addition and several related theories is established: any decision procedure for these theories requires either space 2^εn or nondeterministic time 2^εn2 for some constant ε > O and ...

A perfect matching in a graph H may be viewed as a collection of subgraphs of H, each of which is isomorphic to K₂, whose vertex sets partition the vertex set of H. This is naturally generalized by replacing K₂ by an arbitrary graph G. We show that if G ...

Equations f@@@@ = g@@@@ between polynomial time computable functions can be represented by sets of propositional formulas. If f@@@@ = g@@@@ is provable in certain arithmetic systems, then polynomial length proofs of the representing formulas exist in ...

If π is a graph property, the general node(edge) deletion problem can be stated as follows: Find the minimum number of nodes(edges), whose deletion results in a subgraph satisfying property π. In this paper we show that if π belongs to a rather broad ...