Time Bounded Frequency Computations

Time Bounded Frequency Computations

This disproves a conjecture of Kinber. (2) We give a transparent proof of a generalization of Kinber's result that there exist arbitrarily complex problems admitting a polynomial time frequency computation. Several corollaries provide more insight into the structure of the hierarchy of polynomial time frequency classes. (3) The relationships between polynomial time frequency classes and selecti...

Trading Determinism for Time in Space Bounded Computations

Savitch showed in 1970 that nondeterministic logspace (NL) is contained in deterministic O(log n) space but his algorithm requires quasipolynomial time. The question whether we can have a deterministic algorithm for every problem in NL that requires polylogarithmic space and simultaneously runs in polynomial time was left open. In this paper we give a partial solution to this problem and show t...

Unambiguous Logarithmic Space Bounded Computations

High frequency batch-oriented computations over large sliding time windows

Today’s business workflows are very likely to include batch computations that periodically analyze subsets of data relative to specific time ranges in order to provide strategic information for stakeholders and other interested parties. The frequency of these computations directly impacts on how much updated such information can be, which provides an effective measure of their usefulness. This ...

Non-uniform time sampling for multiple-frequency harmonic balance computations

A time-domain harmonic balance method for the analysis of almost-periodic (multi-harmonics) flows is presented. This method relies on Fourier analysis to derive an efficient alternative to classical time marching schemes for such flows. It has recently received significant attention, especially in the turbomachinery field where the flow spectrum is essentially a combination of the blade passing...