4,357 research outputs found
A Methodology for Simulated Experiments in Interactive Search
Interactive information retrieval has received much attention in recent years, e.g. [7]. Furthermore, increased activity in developing interactive features in search systems used across existing popular Web search engines suggests that interactive systems are being recognised as a promising next step in assisting information search. One of the most challenging problems with interactive systems however remains evaluation.
We describe the general specifications of a methodology for conducting controlled and reproducible experiments in the context of interactive search. It was developed in the AutoAdapt project1 focusing on search in intranets, but the methodology is more generic than that and can be applied to interactive Web search as well. The goal of this methodology is to evaluate the ability of different algorithms to produce domain models that provide accurate suggestions for query modifications. The AutoAdapt project investigates the application of automatically constructed adaptive domain models for providing suggestions for query modifications to the users of an intranet search engine. This goes beyond static models such as the one employed to guide users who search the Web site of the University of Essex which is based on a domain model that has been built in advance using the documents’ markup structure
Moving towards Adaptive Search
Information retrieval has become very popular over the last decade with the advent of the Web. Nevertheless, searching on the Web is very different to searching on smaller, often more structured collections such as intranets and digital libraries. Such collections are the focus of the recently started AutoAdapt project1. The project seeks to aid user search by providing well-structured domain knowledge to assist query modification and navigation. There are two challenges: acquiring the domain knowledge and adapting it automatically to the specific interest of the user community. At the workshop we will demonstrate an implemented prototype that serves as a starting point on the way to truly adaptive search
Using domain models for context-rich user logging
This paper describes the prototype interactive search sys- Tem being developed within the AutoAdapt project1. The AutoAdapt project seeks to enhance the user experience in searching for information and navigating within selected do- main collections by providing structured representations of domain knowledge to be directly explored, logged, adapted and updated to refject user needs. We propose that this structure is a valuable stepping-stone in context-rich logging of user activities within the information seeking environment. Here we describe the primary components that have been implemented and the user interactions that it will support
Fluctuations of Quantum Currents and Unravelings of Master Equations
The very notion of a current fluctuation is problematic in the quantum
context. We study that problem in the context of nonequilibrium statistical
mechanics, both in a microscopic setup and in a Markovian model. Our answer is
based on a rigorous result that relates the weak coupling limit of fluctuations
of reservoir observables under a global unitary evolution with the statistics
of the so-called quantum trajectories. These quantum trajectories are
frequently considered in the context of quantum optics, but they remain useful
for more general nonequilibrium systems.
In contrast with the approaches found in the literature, we do not assume
that the system is continuously monitored. Instead, our starting point is a
relatively realistic unitary dynamics of the full system.Comment: 18 pages, v1-->v2, Replaced the former Appendix B by a (thematically)
different one. Mainly changes in the introductory Section 2+ added reference
Physics at the LHC: a short overview
The CERN Large Hadron Collider (LHC) started operation a few months ago. The
machine will deliver proton-proton and nucleus-nucleus collisions at energies
as high as sqrt(s)=14 TeV and luminosities up to L~10^{34} cm^{-2}s^{-1}, never
reached before. The main open scientific questions that the seven LHC
experiments -- ATLAS, CMS, ALICE, LHCb, TOTEM, LHCf and MOEDAL -- aim to solve
in the coming years are succinctly reviewed.Comment: 9 pages, 16 plots. Invited review talk Hot-Quarks 2010, La
Londe-Les-Maures, July 2010. J. Phys. Conf. Ser. 270, 012001 (2011). Minor
typos correcte
Relating the thermodynamic arrow of time to the causal arrow
Consider a Hamiltonian system that consists of a slow subsystem S and a fast
subsystem F. The autonomous dynamics of S is driven by an effective
Hamiltonian, but its thermodynamics is unexpected. We show that a well-defined
thermodynamic arrow of time (second law) emerges for S whenever there is a
well-defined causal arrow from S to F and the back-action is negligible. This
is because the back-action of F on S is described by a non-globally Hamiltonian
Born-Oppenheimer term that violates the Liouville theorem, and makes the second
law inapplicable to S. If S and F are mixing, under the causal arrow condition
they are described by microcanonic distributions P(S) and P(S|F). Their
structure supports a causal inference principle proposed recently in machine
learning.Comment: 10 page
Planck Scale Boundary Conditions and the Higgs Mass
If the LHC does only find a Higgs boson in the low mass region and no other
new physics, then one should reconsider scenarios where the Standard Model with
three right-handed neutrinos is valid up to Planck scale. We assume in this
spirit that the Standard Model couplings are remnants of quantum gravity which
implies certain generic boundary conditions for the Higgs quartic coupling at
Planck scale. This leads to Higgs mass predictions at the electroweak scale via
renormalization group equations. We find that several physically well motivated
conditions yield a range of Higgs masses from 127-142 GeV. We also argue that a
random quartic Higgs coupling at the Planck scale favors M_H > 150 GeV, which
is clearly excluded. We discuss also the prospects for differentiating
different boundary conditions imposed for \lambda(M_{pl}) at the LHC. A
striking example is M_H = 127\pm 5 GeV corresponding to \lambda(M_{pl})=0,
which would imply that the quartic Higgs coupling at the electroweak scale is
entirely radiatively generated.Comment: 12 pages, 5 figures; references added and other minor improvements,
matches version published in JHE
Recommended from our members
Tevatron-for-LHC Report of the QCD Working Group
The experiments at Run 2 of the Tevatron have each accumulated over 1 fb{sup -1} of high-transverse momentum data. Such a dataset allows for the first precision (i.e. comparisons between theory and experiment at the few percent level) tests of QCD at a hadron collider. While the Large Hadron Collider has been designed as a discovery machine, basic QCD analyses will still need to be performed to understand the working environment. The Tevatron-for-LHC workshop was conceived as a communication link to pass on the expertise of the Tevatron and to test new analysis ideas coming from the LHC community. The TeV4LHC QCD Working Group focused on important aspects of QCD at hadron colliders: jet definitions, extraction and use of Parton Distribution Functions, the underlying event, Monte Carlo tunes, and diffractive physics. This report summarizes some of the results achieved during this workshop
Higgs production in CP-violating supersymmetric cascade decays: probing the `open hole' at the Large Hadron Collider
A benchmark CP-violating supersymmetric scenario (known as 'CPX-scenario' in
the literature) is studied in the context of the Large Hadron Collider (LHC).
It is shown that the LHC, with low to moderate accumulated luminosity, will be
able to probe the existing `hole' in the - plane, which
cannot be ruled out by the LEP data. We explore the parameter space with
cascade decay of third generation squarks and gluino with CP-violating decay
branching fractions. We propose a multi-channel analysis to probe this
parameter space some of which are background free at an integrated luminosity
of 5-10 fb. Specially, multi-lepton final states (3\l,\, 4\l and like
sign di-lepton) are almost background free and have reach for the
corresponding signals with very early data of LHC for both 14 TeV and 7 TeV
center of mass energy.Comment: 24 pages, 9 figures, references added as in the journal versio
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