582 research outputs found
Abstract involutions of algebraic groups and of Kac-Moody groups
Based on the second author's thesis in this article we provide a uniform
treatment of abstract involutions of algebraic groups and of Kac-Moody groups
using twin buildings, RGD systems, and twisted involutions of Coxeter groups.
Notably we simultaneously generalize the double coset decompositions
established by Springer and by Helminck-Wang for algebraic groups and by
Kac-Wang for certain Kac-Moody groups, we analyze the filtration studied by
Devillers-Muhlherr in the context of arbitrary involutions, and we answer a
structural question on the combinatorics of involutions of twin buildings
raised by Bennett-Gramlich-Hoffman-Shpectorov
Large scale Gd-beta-diketonate based organic liquid scintillator production for antineutrino detection
Over the course of several decades, organic liquid scintillators have formed
the basis for successful neutrino detectors. Gadolinium-loaded liquid
scintillators provide efficient background suppression for electron
antineutrino detection at nuclear reactor plants. In the Double Chooz reactor
antineutrino experiment, a newly developed beta-diketonate gadolinium-loaded
scintillator is utilized for the first time. Its large scale production and
characterization are described. A new, light yield matched metal-free companion
scintillator is presented. Both organic liquids comprise the target and "Gamma
Catcher" of the Double Chooz detectors.Comment: 16 pages, 4 figures, 5 table
Large scale Gd-beta-diketonate based organic liquid scintillator production for antineutrino detection
Over the course of several decades, organic liquid scintillators have formed
the basis for successful neutrino detectors. Gadolinium-loaded liquid
scintillators provide efficient background suppression for electron
antineutrino detection at nuclear reactor plants. In the Double Chooz reactor
antineutrino experiment, a newly developed beta-diketonate gadolinium-loaded
scintillator is utilized for the first time. Its large scale production and
characterization are described. A new, light yield matched metal-free companion
scintillator is presented. Both organic liquids comprise the target and "Gamma
Catcher" of the Double Chooz detectors.Comment: 16 pages, 4 figures, 5 table
Certification of nontermination proofs using strategies and nonlooping derivations
© 2014 Springer International Publishing Switzerland. The development of sophisticated termination criteria for term rewrite systems has led to powerful and complex tools that produce (non)termination proofs automatically. While many techniques to establish termination have already been formalized—thereby allowing to certify such proofs—this is not the case for nontermination. In particular, the proof checker CeTA was so far limited to (innermost) loops. In this paper we present an Isabelle/HOL formalization of an extended repertoire of nontermination techniques. First, we formalized techniques for nonlooping nontermination. Second, the available strategies include (an extended version of) forbidden patterns, which cover in particular outermost and context-sensitive rewriting. Finally, a mechanism to support partial nontermination proofs further extends the applicability of our proof checker
Large scale Gd-beta-diketonate based organic liquid scintillator production for antineutrino detection
Over the course of several decades, organic liquid scintillators have formed
the basis for successful neutrino detectors. Gadolinium-loaded liquid
scintillators provide efficient background suppression for electron
antineutrino detection at nuclear reactor plants. In the Double Chooz reactor
antineutrino experiment, a newly developed beta-diketonate gadolinium-loaded
scintillator is utilized for the first time. Its large scale production and
characterization are described. A new, light yield matched metal-free companion
scintillator is presented. Both organic liquids comprise the target and "Gamma
Catcher" of the Double Chooz detectors.Comment: 16 pages, 4 figures, 5 table
Loops under Strategies ... Continued
While there are many approaches for automatically proving termination of term
rewrite systems, up to now there exist only few techniques to disprove their
termination automatically. Almost all of these techniques try to find loops,
where the existence of a loop implies non-termination of the rewrite system.
However, most programming languages use specific evaluation strategies, whereas
loop detection techniques usually do not take strategies into account. So even
if a rewrite system has a loop, it may still be terminating under certain
strategies.
Therefore, our goal is to develop decision procedures which can determine
whether a given loop is also a loop under the respective evaluation strategy.
In earlier work, such procedures were presented for the strategies of
innermost, outermost, and context-sensitive evaluation. In the current paper,
we build upon this work and develop such decision procedures for important
strategies like leftmost-innermost, leftmost-outermost,
(max-)parallel-innermost, (max-)parallel-outermost, and forbidden patterns
(which generalize innermost, outermost, and context-sensitive strategies). In
this way, we obtain the first approach to disprove termination under these
strategies automatically.Comment: In Proceedings IWS 2010, arXiv:1012.533
The prognosis of incurable cachectic cancer patients on home parenteral nutrition: a multi-centre observational study with prospective follow-up of 414 patients.
The IDA-80 measurement evaluation programme on mass spectrometric isotope dilution analysis of uranium and plutonium. Vol.II: Preparation, characterization and transport of test samples
Quotients of incidence geometries
We develop a theory for quotients of geometries and obtain sufficient
conditions for the quotient of a geometry to be a geometry. These conditions
are compared with earlier work on quotients, in particular by Pasini and Tits.
We also explore geometric properties such as connectivity, firmness and
transitivity conditions to determine when they are preserved under the
quotienting operation. We show that the class of coset pregeometries, which
contains all flag-transitive geometries, is closed under an appropriate
quotienting operation.Comment: 26 pages, 5 figure
The dependency pair framework: Combining techniques for automated termination proofs
Abstract. The dependency pair approach is one of the most powerful techniques for automated termination proofs of term rewrite systems. Up to now, it was regarded as one of several possible methods to prove termination. In this paper, we show that dependency pairs can instead be used as a general concept to integrate arbitrary techniques for termination analysis. In this way, the benefits of different techniques can be combined and their modularity and power are increased significantly. We refer to this new concept as the “dependency pair framework ” to distinguish it from the old “dependency pair approach”. Moreover, this framework facilitates the development of new methods for termination analysis. To demonstrate this, we present several new techniques within the dependency pair framework which simplify termination problems considerably. We implemented the dependency pair framework in our termination prover AProVE and evaluated it on large collections of examples.
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