745 research outputs found
Invariance: a Theoretical Approach for Coding Sets of Words Modulo Literal (Anti)Morphisms
Let be a finite or countable alphabet and let be literal
(anti)morphism onto (by definition, such a correspondence is determinated
by a permutation of the alphabet). This paper deals with sets which are
invariant under (-invariant for short).We establish an
extension of the famous defect theorem. Moreover, we prove that for the
so-called thin -invariant codes, maximality and completeness are two
equivalent notions. We prove that a similar property holds in the framework of
some special families of -invariant codes such as prefix (bifix) codes,
codes with a finite deciphering delay, uniformly synchronized codes and
circular codes. For a special class of involutive antimorphisms, we prove that
any regular -invariant code may be embedded into a complete one.Comment: To appear in Acts of WORDS 201
Two-Sided Derivatives for Regular Expressions and for Hairpin Expressions
The aim of this paper is to design the polynomial construction of a finite
recognizer for hairpin completions of regular languages. This is achieved by
considering completions as new expression operators and by applying derivation
techniques to the associated extended expressions called hairpin expressions.
More precisely, we extend partial derivation of regular expressions to
two-sided partial derivation of hairpin expressions and we show how to deduce a
recognizer for a hairpin expression from its two-sided derived term automaton,
providing an alternative proof of the fact that hairpin completions of regular
languages are linear context-free.Comment: 28 page
Small Universal Accepting Networks of Evolutionary Processors with Filtered Connections
In this paper, we present some results regarding the size complexity of
Accepting Networks of Evolutionary Processors with Filtered Connections
(ANEPFCs). We show that there are universal ANEPFCs of size 10, by devising a
method for simulating 2-Tag Systems. This result significantly improves the
known upper bound for the size of universal ANEPFCs which is 18.
We also propose a new, computationally and descriptionally efficient
simulation of nondeterministic Turing machines by ANEPFCs. More precisely, we
describe (informally, due to space limitations) how ANEPFCs with 16 nodes can
simulate in O(f(n)) time any nondeterministic Turing machine of time complexity
f(n). Thus the known upper bound for the number of nodes in a network
simulating an arbitrary Turing machine is decreased from 26 to 16
Electrochemical oxidation and detection of sodium urate in alkaline media on a copper oxides electrode
Electrochemical behaviour of copper oxides electrode in the presence of sodium urate was investigated. The correlation between the anodic oxidation and the amperometric detection of sodium urate in the alkaline medium on copper oxides electrode was analysed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements. The intereference from sodium tartrate presence in the aqueous alkaline solution was tested. Copper oxides electrodes can be used successfully for amperometric detection of both sodium urate and mixture of urate and tartrate as a cumulative response, in alkaline media, the target compound did not interfere each other. Journal of Applied Sciences and Environmental Management Vol. 10(1) 2006: 25-3
Conformations And Relative Stabilities Of The Cis And Trans Isomers In A Series Of Isolated N-phenylamides
The gas-phase conformations of a series of isolated N-phenylamides have been determined from vibrationally resolved electronic spectra obtained by resonant two-photon ionization in a supersonic jet expansion. Both the cis and trans isomers of formanilide were identified, with the cis isomer in 6.5% abundance. The spectral features displayed by this isomer are consistent with a nonplanar geometry which undergoes a large change in the phenyl torsional angle following electronic excitation. The more abundant trans isomer of formanilide adopts a planar structure and is stabilized by 2.5 kcal/mol with respect to the cis isomer. In the excited electronic state the relative stabilities of the two isomers are reversed. Acetanilide, in contrast, is found exclusively as the trans isomer, also having a planar structure. N-Methyl substitution causes a reversal of the relative isomer stabilities found in formanilide and leads to an isomer distribution consisting of approximately 90% E and 10% Z in N-methylformanilide. These experimental observations are compared to previous condensed phase structural determinations as well as to the relative energies and structures predicted from ab initio Hartree-Fock geometry optimizations
A Site Evaluation Campaign for a Ground Based Atmospheric Cherenkov Telescope in Romania
Around the world, several scientific projects share the interest of a global
network of small Cherenkov telescopes for monitoring observations of the
brightest blazars - the DWARF network. A small, ground based, imaging
atmospheric Cherenkov telescope of last generation is intended to be installed
and operated in Romania as a component of the DWARF network. To prepare the
construction of the observatory, two support projects have been initiated.
Within the framework of these projects, we have assessed a number of possible
sites where to settle the observatory. In this paper we submit a brief report
on the general characteristics of the best four sites selected after the local
infrastructure, the nearby facilities and the social impact criteria have been
applied.Comment: 6 pages, 5 Postscript figure
PNEPs, NEPs for context free parsing: Application to natural language processing
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-02478-8_59Proceedings of 10th International Work-Conference on Artificial Neural Networks, IWANN 2009, Salamanca, Spain.This work tests the suitability of NEPs to parse languages. We propose PNEP, a simple extension to NEP, and a procedure to translate a grammar into a PNEP that recognizes the same language. These parsers based on NEPs do not impose any additional constrain
to the structure of the grammar, which can contain all kinds of recursive, lambda or ambiguous rules. This flexibility makes this procedure specially suited for Natural Languge Processing (NLP). In a first proof with a simplified English grammar, we got a performance (a linear time complexity) similar to that of the most popular syntactic parsers in the NLP area (Early and its derivatives). All the possible derivations for ambiguous grammars were generatedThis work was partially supported by MEC, project TIN2008-02081/TIN and by DGUI CAM/UAM, project CCG08-UAM/TIC-4425
Detecting One-variable Patterns
Given a pattern such that
, where is a
variable and its reversal, and
are strings that contain no variables, we describe an
algorithm that constructs in time a compact representation of all
instances of in an input string of length over a polynomially bounded
integer alphabet, so that one can report those instances in time.Comment: 16 pages (+13 pages of Appendix), 4 figures, accepted to SPIRE 201
Safeguarding children in dentistry: 1. Child protection training, experience and practice of dental professionals with an interest in paediatric dentistry
* Few dental professionals with child protection training have experience of making referrals.
* There is a wide gap in practice between recognising signs of child abuse and neglect and responding effectively.
* This may indicate missed opportunities to save children from continuing abuse.
* There is a need for improved child protection information, support and training for dental professionals.
Abstract
Following several highly publicised inquiries into the deaths of children from abuse and neglect, there has been much recent interest in the role and responsibility of all health professionals to protect children at risk of maltreatment. The findings of a postal questionnaire, sent in March 2005 to 789 dentists and dental care professionals with an interest in paediatric dentistry working in varied settings in the UK, are presented in a two-part report and discussed in the context of current multi-agency good practice in safeguarding and promoting the welfare of children. This first part explores reported child protection training, experience and practice. There was a significant gap between recognising signs of abuse and responding effectively: 67% of respondents had suspected abuse or neglect of a child patient at some time in their career but only 29% had ever made a child protection referral. The dental profession is alerted to the need to ensure necessary appropriate action to safeguard children is always taken when child abuse or neglect are suspected
Simulating accepting networks of evolutionary processors with filtered connections by accepting evolutionary P systems
In this work, we propose a variant of P system based on the rewriting of string-objects by means of evolutionary rules. The membrane structure of such a P system seems to be a very natural tool for simulating the filters in accepting networks of evolutionary processors with filtered connections. We discuss an informal construction supporting this simulation. A detailed proof is to be considered in an extended version of this work
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