This paper gives an overview on the structure and the use of Paclib, a new system for parallel algebraic computation on shared memory computers. Paclib has been developed as a professional tool for the simple design and eecient implementation of parallel algorithms in computer algebra and related areas. It provides concurrency, shared memory communication , non-determinism, speculative parallel...

We give an overview on Paclib, a library for parallel algebraic computation on shared memory multiprocessors. Paclib is essentially a package of C functions that provide the basic objects and methods of computer algebra in a parallel context. The Paclib programming model supports concurrency, shared memory communication, non-determinism and speculative parallelism. The system is based on a heap...

Differential power analysis (DPA) has become a real-world threat to the security of cryptographic hardware devices such as smart-cards. By using cheap and readily available equipment, attacks can easily compromise algorithms running on these devices in a non-invasive manner. Adding non-determinism to the execution of cryptographic algorithms has been proposed as a defence against these attacks....

Reproducibility is an essential component of the scientific method. In order to validate the correctness or facilitate the extension of a computational result, it should be possible to re-run a published result and verify that the same results are produced. However, reproducing a computational result is surprisingly difficult: non-determinism and other factors may make it impossible to get the ...

Let NDTIME(f(n),g(n)) denote the class of problems solvable in O(g(n)) time by a multi-tape Turing machine using an f(n)-bit non-deterministic oracle, and let DTIME(g(n)) = NDTIME(0, g(n)). We show that if all-pairs shortest paths problem (APSP) for directed graphs with N vertices integer edge weights within super-exponential range { −2Nk+o(1),....,2Nk+o(1) }, k≥1 does not admit truly subcubic ...

One-way and two-way cellular language acceptors with restricted non-determinism are investigated. The number of nondeterministic state transitions is regarded as limited resource which depends on the length of the input. We center our attention to real-time, linear-time and unrestricted-time computations. A speed-up result that allows any linear-time computation to be sped-up to real-time is pr...

Matrix Graph Grammars (MGG) is a novel approach to the study of graph dynamics ([15]). In the present contribution we look at MGG as a formal grammar and as a model of computation, which is a necessary step in the more ambitious program of tackling complexity theory through MGG. We also study its relation with other well-known models such as Turing machines (TM) and Boolean circuits (BC) as wel...

We introduce a framework for managing as a whole the space of a narrowing computation. The aim of our framework is to find a finite representation of an infinite narrowing space. This, in turn, allows us to replace an infinite enumeration of computed answers with an equivalent finite representation. We provide a semidecidable condition for this result. Our framework is intended to be used by im...

This paper presents a detailed comparison between two search optimization techniques for large vocabulary speech recognition – one based on word-conditioned tree search (WCTS) and one based on weighted finite-state transducers (WFSTs). Existing North American Business News systems from RWTH and AT&T representing each of the two approaches, were modified to remove variations in model data and ac...

I propose to develop a deterministic parallel framework for performing iterative computation on a graph which schedules work on vertices based upon a valid coloring. Preliminary work modifying Graphlab, a parallel framework for implementing iterative machine learning algorithms on data graphs, has demonstrated the merits of this approach by improving performance and eliminating non-determinism....