895 research outputs found
Large J expansion in ABJM theory revisited
Recently there has been progress in the computation of the anomalous
dimensions of gauge theory operators at strong coupling by making use of
AdS/CFT correspondence. On string theory side they are given by dispersion
relations in the semiclassical regime. We revisit the problem of large charges
expansion of the dispersion relations for simple semiclassical strings in
background. We present the calculation of the
corresponding anomalous dimensions of the gauge theory operators to an
arbitrary order using three different methods. Although the results of the
three methods look different, power series expansions show their consistency.Comment: 24 pages, 2 figure
Generalized pulsating strings
In this paper we consider new solutions for pulsating strings. For this
purpose we use tha idea of the generalized ansatz for folded and circular
strings in hep-th/0311004. We find the solutions to the resulting
Neumann-Rosochatius integrable system and the corrections to the energy. To do
that we use the approach developed by Minahan in hep-th/0209047 and find that
the corrections are quite different from those obtained in that paper and
hep-th/0310188. We conclude with comments on our solutions and obtained
corrections to the energy, expanded to the leading order in lambda.Comment: v.2 references added, citations corrected, 18 page
Cognitive support for older people from multimedia options
If older users of multimedia displays could select among presentation options, would they choose display combinations that supported their performance? After three short touch-screen tasks which measured the perceptual and cognitive abilities of 50 older adults, they answered questions about a route on an online map that could be accompanied by written and/or spoken text. Half the participants saw animated routes; and they were less accurate answering questions than those who saw static routes but this did not affect people’s multimedia choices which, although diverse, were systematic. Spoken text was more often selected by people who had lower scores on the spatial working memory task, than by the older adults with higher scores. This suggests that older people with cognitive limitations recognise ways in which multimedia information can be supportive
A note on spin chain/string duality
Recently a significant progress in matching the anomalous dimensions of
certain class of operators in N=4 SYM theory and rotating strings was made. The
correspondence was established mainly using Bethe ansatz technique applied to
the spin s Heisenberg model. In a recent paper Kruczenski (hep-th/0311203)
suggested to solve the Heisenberg model by using of sigme model approach. In
this paper we generalize the solutions obtained by Kruczenski and comment on
the dual string theory. It turns out that our solutions are related to the so
called Neumann-Rosochatius integrable system. We comment on the spin chain
solutions and on the string/gauge theory correspondence.Comment: v.2 One reference added, typos corrected, 21 page
SYNTHESIS OF SOME NOVEL BENZIMIDAZOL-2-ONE DERIVATIVES
For the development of medical and pharmaceutical chemistry is essential to optimize and change relevant structures, possessing biological activity. Herein we report the synthesis of some novel 1H-benzimidazolon-2-one derivatives using aza-Michael addition.For the development of medical and pharmaceutical chemistry is essential to optimize and change relevant structures, possessing biological activity. Herein we report the synthesis of some novel 1H-benzimidazolon-2-one derivatives using aza-Michael addition
An Analysis and Forecast of Software and Services Research in Bulgaria
In the last 40 years much has been achieved in Software Engineering
research and still more is to be done. Although significant progress is
being made on several fronts in Service-Oriented Architecture (SOA), there
is still no set of clear, central themes to focus research activity on. A task
within the EU FP7 Sister project aimed at defining research priorities for
the Faculty of Mathematics and Informatics (Sofia University) in the area of
Software and Services. A dedicated methodology was proposed and developed,
based on various sources of information. The information accumulated
was systematised and processed according to this methodology. The final
results obtained are described and discussed here.* The work reported in this paper is partly supported by the SISTER project, funded by the
European Commission in FP7-SP4 Capacities via agreement no. 205030
Data mining: a tool for detecting cyclical disturbances in supply networks.
Disturbances in supply chains may be either exogenous or endogenous. The ability automatically to detect, diagnose, and distinguish between the causes of disturbances is of prime importance to decision makers in order to avoid uncertainty. The spectral principal component analysis (SPCA) technique has been utilized to distinguish between real and rogue disturbances in a steel supply network. The data set used was collected from four different business units in the network and consists of 43 variables; each is described by 72 data points. The present paper will utilize the same data set to test an alternative approach to SPCA in detecting the disturbances. The new approach employs statistical data pre-processing, clustering, and classification learning techniques to analyse the supply network data. In particular, the incremental k-means
clustering and the RULES-6 classification rule-learning algorithms, developed by the present authors’ team, have been applied to identify important patterns in the data set. Results show that the proposed approach has the capability automatically to detect and characterize network-wide cyclical disturbances and generate hypotheses about their root cause
Compact Measurement Station for Low Energy Proton Beams
A compact, remote controlled, cost efficient diagnostic station has been
developed to measure the charge, the profile and the emittance for low energy
proton beams. It has been installed and tested in the proton beam line of the
Project Prometheus at SANAEM of the Turkish Atomic Energy Authority.Comment: 7 pages 2 column
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