4,314 research outputs found
Transport in the Trans-Pennine Corridor: Present Conditions and Future Options. Interregional Study Working Paper 3.
This paper reports on a desk study carried out by the Institute for Transport Studies as part of a wider study of opportunities for inter-regional working in the trans-Pennine corridor, considering economic, environmental and transport issues. It draws together available information on transport and movement flows in the trans-Pennine corridor. These patterns of movement are examined from a broad perspective which considers intra-regional, inter- regional and international movements within and across the study area. The report proposes a regional package approach to transport, based on demand management and modal transfer
A real-time, dual processor simulation of the rotor system research aircraft
A real-time, man-in-the loop, simulation of the rotor system research aircraft (RSRA) was conducted. The unique feature of this simulation was that two digital computers were used in parallel to solve the equations of the RSRA mathematical model. The design, development, and implementation of the simulation are documented. Program validation was discussed, and examples of data recordings are given. This simulation provided an important research tool for the RSRA project in terms of safe and cost-effective design analysis. In addition, valuable knowledge concerning parallel processing and a powerful simulation hardware and software system was gained
The use and effectiveness of the eLib subject gateways: a preliminary investigation
Internet subject gateways were set up under the Electronic Libraries Programme (eLib) in order to address some of the problems of searching the Internet which have been identified by information professionals, i.e. locating relevant, good quality information. This preliminary study examines the extent to which academics in two universities use three eLib subject gateways (EEVL, OMNI and SOSIG). The results are generally encouraging for the eLib programme, but it is necessary for the gateways to be more effectively promoted. The study also found that academics do not have the same misgivings about the general search engines as the information professionals and seem to use them more readily than the gateways
Atom-molecule coherence in a one-dimensional system
We study a model of one-dimensional fermionic atoms that can bind in pairs to
form bosonic molecules. We show that at low energy, a coherence develops
between the molecule and fermion Luttinger liquids. At the same time, a gap
opens in the spin excitation spectrum. The coherence implies that the order
parameters for the molecular Bose-Einstein Condensation and the atomic BCS
pairing become identical. Moreover, both bosonic and fermionic charge density
wave correlations decay exponentially, in contrast with a usual Luttinger
liquid. We exhibit a Luther-Emery point where the systems can be described in
terms of noninteracting pseudofermions. At this point, we provide closed form
expressions for the density-density response functions.Comment: 5 pages, no figures, Revtex 4; (v2) added a reference to
cond-mat/0505681 where related results are reported; (v3) Expression of
correlation functions given in terms of generalized hypergeometric function
The Effect of Wireless Symmetries on Cryptoanalysis
The essential unification of thin clients and suffix trees is an unfortunate quandary. In fact, few researchers would disagree with the understanding of vacuum tubes, which embodies the structured principles of cy- berinformatics. Here, we construct new atomic theory (Museum), disproving that randomized algorithms and public-private key pairs are mostly incompatible
Verifying Temporal Regular Properties of Abstractions of Term Rewriting Systems
The tree automaton completion is an algorithm used for proving safety
properties of systems that can be modeled by a term rewriting system. This
representation and verification technique works well for proving properties of
infinite systems like cryptographic protocols or more recently on Java Bytecode
programs. This algorithm computes a tree automaton which represents a (regular)
over approximation of the set of reachable terms by rewriting initial terms.
This approach is limited by the lack of information about rewriting relation
between terms. Actually, terms in relation by rewriting are in the same
equivalence class: there are recognized by the same state in the tree
automaton.
Our objective is to produce an automaton embedding an abstraction of the
rewriting relation sufficient to prove temporal properties of the term
rewriting system.
We propose to extend the algorithm to produce an automaton having more
equivalence classes to distinguish a term or a subterm from its successors
w.r.t. rewriting. While ground transitions are used to recognize equivalence
classes of terms, epsilon-transitions represent the rewriting relation between
terms. From the completed automaton, it is possible to automatically build a
Kripke structure abstracting the rewriting sequence. States of the Kripke
structure are states of the tree automaton and the transition relation is given
by the set of epsilon-transitions. States of the Kripke structure are labelled
by the set of terms recognized using ground transitions. On this Kripke
structure, we define the Regular Linear Temporal Logic (R-LTL) for expressing
properties. Such properties can then be checked using standard model checking
algorithms. The only difference between LTL and R-LTL is that predicates are
replaced by regular sets of acceptable terms
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