7,183 research outputs found
Non-supersymmetric deformations of the dual of a confining gauge theory
We introduce a computational technique for studying non-supersymmetric
deformations of domain wall solutions of interest in AdS/CFT. We focus on the
Klebanov-Strassler solution, which is dual to a confining gauge theory. From an
analysis of asymptotics we find that there are three deformations that leave
the ten-dimensional supergravity solution regular and preserve the global
bosonic symmetries of the supersymmetric solution. Also, we show that there are
no regular near-extremal deformations preserving the global symmetries, as one
might expect from the existence of a gap in the gauge theory.Comment: 18 pages, latex, published as JHEP 0305 (2003) 03
The structure of Gelfand-Levitan-Marchenko type equations for Delsarte transmutation operators of linear multi-dimensional differential operators and operator pencils. Part 1
An analog of Gelfand-Levitan-Marchenko integral equations for multi-
dimensional Delsarte transmutation operators is constructed by means of
studying their differential-geometric structure based on the classical Lagrange
identity for a formally conjugated pair of differential operators. An extension
of the method for the case of affine pencils of differential operators is
suggested.Comment: 12 page
Structural Refinement for the Modal nu-Calculus
We introduce a new notion of structural refinement, a sound abstraction of
logical implication, for the modal nu-calculus. Using new translations between
the modal nu-calculus and disjunctive modal transition systems, we show that
these two specification formalisms are structurally equivalent.
Using our translations, we also transfer the structural operations of
composition and quotient from disjunctive modal transition systems to the modal
nu-calculus. This shows that the modal nu-calculus supports composition and
decomposition of specifications.Comment: Accepted at ICTAC 201
Studies on the fish ponds at Pitipana, Negombo 1: seasonal and diurnal variation of some hydrobiological factors
The present paper is a part of a detailed investigation on the biology of grey mullet, Mugli cephalus L., and the feasibility of its culture in the brackish waters of Sri Lanka. The authors present the results of investigation on the water quality of five experimental ponds at the Pitipana Brackishwater Fisheries Station, Negombo, carried out over a period of one year, December 1976 to November 1977, together with studies on the primary productivity are presented
Hydrobiology of Colombo (Beira) Lake, 1. Diurnal variations in temperature, hydrochemical factors and zooplankton
An extensive study of the hydrobiology of the Colombo Lake was initiated by the authors in May 1969 as a contribution to the International Biological Program (Productivity of freshwater communities) by the Department of Zoology, Vidyalankara University of Ceylon, Kelaniya. The Colombo Lake often referred to as the Beira Lake covers an area of approximately 160 acres. The water is usually very turbid with a greenish blue appearance due to the presence of large quantities of blue green algae
Fish fauna of a coastal lagoon in Sri Lanka: distribution and seasonal variation
In this paper results of investigations carried out over the period of September 1977 to August 1978 are presented. These data were collected in the course of a detailed investigation into the biology and the eco-physiology of the young grey mullet and the grey mullet fishery of the Negombo Lagoon. In this paper the distribution and seasonal variation of fin fish species within the Negombo Lagoon are presented
Evaluation of latent heat storage in mortars containing microencapsulated paraffin waxes – a selection of optimal composition and binders
The application of phase change materials (PCMs) in mortars have been extensively researched, however, most studies are focused in one single binder. Conducting comparative assessments using different binders can facilitate the development of compositions with adequate heat storage and suitable mechanical properties. In this work, several PCM-mortars using cement, lime and gypsum as binders, have been studied using a laboratory simulation that mimicked the day/night temperature changes that the material will be subject during service applications. It has been demonstrated that the addition of PCMs in mortars allows the material to retain heat, indicating that these mortars can have a positive impact on the overall energy demand of buildings. There is a combined effect of delay and lowering of temperature peaks, triggered by the heat released from the capsules. The cells with PCMs showed not only a smaller temperature gradient between night and day, but it also exhibited lower peaks. The tests conducted with this laboratory setup prove that PCMs can be successfully mixed into mortars without compromising its durability, hence their applicability as wall renderings.</p
Throughput of ADSL modems
This paper considers the throughput of ADSL (Asymmetric Digital Subscriber Line) modems, used for high-speed data transmission over relatively unreliable connections, e.g. copper telephone wires. The modem technique uses an error correcting code and interleaving. The settings include a grouping factor which affects the amount of data per code word, the number of redundant bytes per code word and the interleave depth . The influence of these parameters on both the effective data transmission rate and the resulting error rate in the received signal are determined for two error situations: random errors and bursts of errors. An approximate analysis for the random error case of the throughput of a TCP (Transport Control Protocol) connection using an ADSL modem shows that maximum throughput is obtained for the highest values of and
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