35,089 research outputs found
Evolving MultiAlgebras unify all usual sequential computation models
It is well-known that Abstract State Machines (ASMs) can simulate
"step-by-step" any type of machines (Turing machines, RAMs, etc.). We aim to
overcome two facts: 1) simulation is not identification, 2) the ASMs simulating
machines of some type do not constitute a natural class among all ASMs. We
modify Gurevich's notion of ASM to that of EMA ("Evolving MultiAlgebra") by
replacing the program (which is a syntactic object) by a semantic object: a
functional which has to be very simply definable over the static part of the
ASM. We prove that very natural classes of EMAs correspond via "literal
identifications" to slight extensions of the usual machine models and also to
grammar models. Though we modify these models, we keep their computation
approach: only some contingencies are modified. Thus, EMAs appear as the
mathematical model unifying all kinds of sequential computation paradigms.Comment: 12 pages, Symposium on Theoretical Aspects of Computer Scienc
Evolving database systems : a persistent view
Submitted to POS7 This work was supported in St Andrews by EPSRC Grant GR/J67611 "Delivering the Benefits of Persistence"Orthogonal persistence ensures that information will exist for as long as it is useful, for which it must have the ability to evolve with the growing needs of the application systems that use it. This may involve evolution of the data, meta-data, programs and applications, as well as the users' perception of what the information models. The need for evolution has been well recognised in the traditional (data processing) database community and the cost of failing to evolve can be gauged by the resources being invested in interfacing with legacy systems. Zdonik has identified new classes of application, such as scientific, financial and hypermedia, that require new approaches to evolution. These applications are characterised by their need to store large amounts of data whose structure must evolve as it is discovered by the applications that use it. This requires that the data be mapped dynamically to an evolving schema. Here, we discuss the problems of evolution in these new classes of application within an orthogonally persistent environment and outline some approaches to these problems.Postprin
Signatures of Parton Exogamy in e+ e- -> W+ W- -> hadrons
We propose possible signatures of `exogamous' combinations between partons in
the different W+ and W- hadron showers in e+e- -> W+W- events with purely
hadronic final states. Within the space-time model for hadronic shower
development that we have proposed previously, we find a possible difference of
about 10 % between the mean hadronic multiplicity in such purely hadronic final
states and twice the hadronic multiplicity in events in which one W decays
hadronically and the other leptonically, i.e., \ne 2 ,
associated with the formation of hadronic clusters by `exogamous' pairs of
partons. We discuss the dependence of this possible difference in multiplicity
on the center-of-mass energy, on the hadron momenta, and on the angular
separation between the dijets. If it were observed, any such
multiplicity difference would indicate that the W's do not hadronize
independently, and hence raise questions about the accuracy with which the W
mass could be determined from purely hadronic final states.Comment: 14 pages including 5 postscript figure
Predictive genomics: A cancer hallmark network framework for predicting tumor clinical phenotypes using genome sequencing data
We discuss a cancer hallmark network framework for modelling
genome-sequencing data to predict cancer clonal evolution and associated
clinical phenotypes. Strategies of using this framework in conjunction with
genome sequencing data in an attempt to predict personalized drug targets, drug
resistance, and metastasis for a cancer patient, as well as cancer risks for a
healthy individual are discussed. Accurate prediction of cancer clonal
evolution and clinical phenotypes will have substantial impact on timely
diagnosis, personalized management and prevention of cancer.Comment: 5 figs, related papers, visit lab homepage:
http://www.cancer-systemsbiology.org, Seminar in Cancer Biology, 201
Thoughts on heavy-ion physics in the high luminosity era: the soft sector
This document summarizes thoughts on opportunities in the soft-QCD sector
from high-energy nuclear collisions at high luminosities.Comment: 19 page
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