The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
A lower bound for the time-space trade-off of pebble games on PD-Graphs (which represent computations of push-down automata or recursion schemes) is proved, that is only a bit lower than the best known upper bound (the lower and upper time bound is about n ?? 2 logn/log(s/log n)). The best lower bound known up to now is the bound for linear recursion (about n ?? log n/log(s/log n) for s ≫ log n.
A generalization of Dobkin and Lipton's element uniqueness problem is introduced: for any fixed undirected graph G on vertex set {v1, v2, ..., vn}, the problem is to determine, given n real numbers x1, x2, ..., xn, whether xi ≠ xj for every edge {vi, vj} in G. This problem is shown to have upper and lower bounds of Θ(nlogn) linear comparisons if G is any dense graph. The proof of the lower bound involves...
A model of VLSI computation suitable for the description of algorithms at a high level is introduced. The model is basically a language to express parallel computations which can be efficiently implemented by a VLSI circuit. This language is used to describe area-time efficient algorithms for a few well known graph problems. The exact complexity of these algorithms and their relevance to recent work...
We define a language L and show that its time and space complexities T and S must satisfy T2S ≥ cn3 even allowing machines with multiple (non random) access to the input.
Deterministic exponential lower time bounds are obtained for analyzing monadic recursion schemes, multi-variable recursion schemes, and recursive programs. The lower bound for multivariable recursion schemes holds for any domain of interpretation with at least two elements. The lower bound for recursive programs holds for any recursive programming language with a nontrivial predicate test (i.e. a...
A general paradigm for relating measures of succinctness of representation and complexity theory is presented. The measures are based on the new Private and Blindfold Alternation machines. These measures are used to indicate the inherent information (or "randomness") of a string, but with respect to time and space complexity classes. These measures are then used to show that the existence...
We examine the class of matrices that satisfy Commoner's sufficient condition for total unimodularity [C], which we call restricted totally unimodular (RTUM). We show that a matrix is RTUM if and only if it can be decomposed in a very simple way into the incidence matrices (or their transposes) of bipartite graphs or directed graphs, and give a linear time algorithm to perform this task. Based on...
In this paper we will investigate transformations that serve as tools in the design of new data structures. Specifically, we study general methods for converting static structures (in which all elements are known before any searches are performed) to dynamic structures (in which the insertion of a new element can be mixed with searches). We will see three classes of such transformations (each based...
We analyze the computational complexity of determining whether F is satisfiable when F is a formula of the classical predicate calculus which obeys certain syntactic restrictions. For example, for the monadic predicate calculus and the Gödel or ∃ ... ∃∀∀∃ ... ∃ prefix class we obtain lower and upper nondeterministic time bounds of the form cn/log n. The main tool in in these proofs is a finite version...
At the heart of a number of arithmetic complexity problems are some basic questions in tensor analysis. Questions regarding the complexity of multiplication operations which are n-linear are most easily studied in a tensor analytic framework. Certain results of tensor analysis are used in this paper to provide insight into the solution of some of these problems. Methods are given to determine a partial...
Fault detecting test sets to detect multiple stuck-at-faults in certain networks realizing Reed-Muller canonic expressions are given. It is shown that to detect t faults, t ≥ 1, in a network realizing an arbitrary n-variable logic function only 4 + Σ i=1 [log22t] (in) tests need be applied ([x] is the integer part of x) and that these tests are independent of the function being realized. Techniques...
The computational power of 2-way pushdown automata with m additional counters (called mC-PDA) is investigated. It is shown that any multi-tape Turingmachine (with a two-way input tape) which accepts within time T(n), where n is the input length, can be simulated by a 3C-PDA whose counters are bounded by T(n) and that any such Turing machine can also be simulated by a 2C-PDA whose counters are bounded...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.