3,092 research outputs found
A Non-renormalization Theorem for the Wilsonian Gauge Couplings in Supersymmetric Theories
We show that the holomorphic Wilsonian beta-function of a renormalizable
asymptotically free supersymmetric gauge theory with an arbitrary semi-simple
gauge group, matter content, and renormalizable superpotential is exhausted at
1-loop with no higher loops and no non-perturbative contributions. This is a
non-perturbative extension of the well known result of Shifman and Vainshtein.Comment: 10 pages, LaTeX; added references and clarified credit
Chemical ordering beyond the superstructure in long-range ordered systems
To describe chemical ordering in solid solutions systems Warren-Cowley
short-range parameters are ordinarily used. However, they are not directly
suited for application to long-range ordered systems, as they do not converge
to zero for large separations. It is the aim of this paper to generalize the
theory to long-range ordered systems and quantitatively discuss chemical
short-range order beyond the superstructure arrangements. This is demonstrated
on the example of a non-stoichiometric B2-ordered intermetallic alloy.
Parameters of interatomic potentials are taken from an embedded atom method
(EAM) calculations and the degree of order is simulated by the Monte Carlo
method. Both on-lattice and off-lattice methods, where the latter allows
individual atoms to deviate from their regular lattice sites, were used, and
the resulting effects are discussed
A Testability Analysis Framework for Non-Functional Properties
This paper presents background, the basic steps and an example for a
testability analysis framework for non-functional properties
Constraining Holocene hydrological changes in the CarpathianâBalkan region using speleothem δ18O and pollen-based temperature reconstructions
Here we present a speleothem isotope record (POM2) from AscunsÄ Cave (Romania) that provides new data on past climate changes in the CarpathianâBalkan region from 8.2 ka until the present. This paper describes an approach to constrain the effect of temperature changes on calcite δ18O values in stalagmite POM2 over the course of the middle Holocene (6â4 ka), and across the 8.2 and 3.2 ka rapid climate change events. Independent pollen temperature reconstructions are used to this purpose. The approach combines the temperature-dependent isotope fractionation of rain water during condensation and fractionation resulting from calcite precipitation at the given cave temperature. The only prior assumptions are that pollen-derived average annual temperature reflects average cave temperature, and that pollen-derived coldest and warmest month temperatures reflect the range of condensation temperatures of rain above the cave site. This approach constrains a range of values between which speleothem δ18O changes should be found if controlled only by surface temperature variations at the cave site. Deviations of the change in δ18Ocspel values from the calculated temperature-constrained range of change are interpreted towards large-scale variability of climateâhydrology.
Following this approach, we show that an additional âź0.6â° enrichment of δ18Oc in the POM2 stalagmite was caused by changing hydrological patterns in SW Romania across the middle Holocene, most likely comprising local evaporation from the soil and an increase in Mediterranean moisture δ18O. Further, by extending the calculations to other speleothem records from around the entire Mediterranean basin, it appears that all eastern Mediterranean speleothems recorded a similar isotopic enrichment due to changing hydrology, whereas all changes recorded in speleothems from the western Mediterranean are fully explained by temperature variation alone. This highlights a different hydrological evolution between the two sides of the Mediterranean.
Our results also demonstrate that during the 8.2 ka event, POM2 stable isotope data essentially fit the temperature-constrained isotopic variability. In the case of the 3.2 ka event, an additional climate-related hydrological factor is more evident. This implies a different rainfall pattern in the Southern Carpathian region during this event at the end of the Bronze Age
Online Diversity Control in Symbolic Regression via a Fast Hash-based Tree Similarity Measure
Diversity represents an important aspect of genetic programming, being
directly correlated with search performance. When considered at the genotype
level, diversity often requires expensive tree distance measures which have a
negative impact on the algorithm's runtime performance. In this work we
introduce a fast, hash-based tree distance measure to massively speed-up the
calculation of population diversity during the algorithmic run. We combine this
measure with the standard GA and the NSGA-II genetic algorithms to steer the
search towards higher diversity. We validate the approach on a collection of
benchmark problems for symbolic regression where our method consistently
outperforms the standard GA as well as NSGA-II configurations with different
secondary objectives.Comment: 8 pages, conference, submitted to congress on evolutionary
computatio
PACE: Pattern Accurate Computationally Efficient Bootstrapping for Timely Discovery of Cyber-Security Concepts
Public disclosure of important security information, such as knowledge of
vulnerabilities or exploits, often occurs in blogs, tweets, mailing lists, and
other online sources months before proper classification into structured
databases. In order to facilitate timely discovery of such knowledge, we
propose a novel semi-supervised learning algorithm, PACE, for identifying and
classifying relevant entities in text sources. The main contribution of this
paper is an enhancement of the traditional bootstrapping method for entity
extraction by employing a time-memory trade-off that simultaneously circumvents
a costly corpus search while strengthening pattern nomination, which should
increase accuracy. An implementation in the cyber-security domain is discussed
as well as challenges to Natural Language Processing imposed by the security
domain.Comment: 6 pages, 3 figures, ieeeTran conference. International Conference on
Machine Learning and Applications 201
Go with the Flow - Design of Cloud Logistics Service Blueprints
By adopting principles of cloud computing to the \ logistics domain the paradigm of Cloud Logistics is derived. It \ appears to be a promising paradigm in order to evolve logistics \ into being more flexible and collaborative. Yet, appropriate \ concepts that enable the cloud logistics paradigm are missing. \ In the paper, existing body of literature is reviewed and a \ definition and a framework of cloud logistics is given. Further, \ service blueprinting is combined with domain engineering and \ general morphological analysis in order to create a suitable \ method for designing cloud oriented service blueprints. Those \ are focusing on domain-specific flows and transformations \ enabling cloud oriented business collaboration. The method \ is applied to the logistics domain and a cloud logistics service \ blueprint is designed. Finally, the concept is evaluated with \ real use cases from logistics service providers
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