2,556 research outputs found
Reasoning in ELH w.r.t. General Concept Inclusion Axioms
In the area of Description Logic (DL) based knowledge representation, research on reasoning w.r.t. general terminologies has mainly focused on very expressive DLs. Recently, though, it was shown for the DL EL, providing only the constructors conjunction and existential restriction, that the subsumption problem w.r.t. cyclic terminologies can be decided in polynomial time, a surprisingly low upper bound. In this paper, we show that even admitting general concept inclusion (GCI) axioms and role hierarchies in EL terminologies preserves the polynomial time upper bound for subsumption. We also show that subsumption becomes co-NP hard when adding one of the constructors number restriction, disjunction, and `allsome', an operator used in the DL k-rep. An interesting implication of the first result is that reasoning over the widely used medical terminology snomed is possible in polynomial time
Subsumption and Instance Problem in ELH w.r.t. General TBoxes
Recently, it was shown for the DL EL that subsumption and instance problem w.r.t. cyclic terminologies can be decided in polynomial time. In this paper, we show that both problems remain tractable even when admitting general concept inclusion axioms and simple role inclusion axioms
Probing small parton densities in ultraperipheral and collisions at the LHC
We calculate production rates for several hard processes in ultraperipheral
proton-nucleus and nucleus-nucleus collisions at the LHC. The resulting high
rates demonstrate that some key directions in small research proposed for
HERA will be accessible at the LHC through these ultraperipheral processes.
Indeed, these measurements can extend the HERA range by roughly a factor of
10 for similar virtualities. Nonlinear effects on the parton densities will
thus be significantly more important in these collisions than at HERA.Comment: Submitted to Phys. Rev. Lett., 4 pages, 5 figure
Isoliquiritigenin, a Strong nod Gene- and Glyceollin Resistance- Inducing Flavonoid from Soybean Root Exudate
Isoflavonoid signal molecules from soybean (Glycine max (L.) Merr.) seed and root exudate induce the transcription of nodulation (nod) genes in Bradyrhizobium japonicum. In this study, a new compound with symbiotic activity was isolated from soybean root exudate. The isolated 2',4',4-trihydroxychalcone (isoliquiritigenin) is characterized by its strong inducing activity for the nod genes of B. japonicum. These genes are already induced at concentrations 1 order of magnitude below those required of the previously described isoflavonoid inducers genistein and daidzein. Isoliquiritigenin is also a potent inducer of glyceollin resistance in B. japonicum, which renders this bacterium insensitive to potentially bactericidal concentrations of glyceollin, the phytoalexin of G. max. No chemotactic effect of isoliquiritigenin was observed. The highly efficient induction of nod genes and glyceollin resistance by isoliquiritigenin suggests the ecological significance of this compound, although it is not a major flavonoid constituent of the soybean root exudate in quantitative terms
Integral Geometric Dual Distributions of Multilinear Models
We propose an integral geometric approach for computing dual distributions
for the parameter distributions of multilinear models. The dual distributions
can be computed from, for example, the parameter distributions of conics,
multiple view tensors, homographies, or as simple entities as points, lines,
and planes. The dual distributions have analytical forms that follow from the
asymptotic normality property of the maximum likelihood estimator and an
application of integral transforms, fundamentally the generalised Radon
transforms, on the probability density of the parameters. The approach allows
us, for instance, to look at the uncertainty distributions in feature
distributions, which are essentially tied to the distribution of training data,
and helps us to derive conditional distributions for interesting variables and
characterise confidence intervals of the estimates
Recursive Calculation of Effective Potential and Variational Resummation
We set up a method for a recursive calculation of the effective potential
which is applied to a cubic potential with imaginary coupling. The result is
resummed using variational perturbation theory (VPT), yielding an exponentially
fast convergence.Comment: Author Information under
http://www.physik.fu-berlin.de/~kleinert/institution.html Latest update of
paper (including all PS fonts) at
http://www.physik.fu-berlin.de/~kleinert/350
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