460 research outputs found
Large-Spin Expansions of GKP Strings
We demonstrate that the large-spin expansion of the energy of
Gubser-Klebanov-Polyakov (GKP) strings that rotate in RxS2 and AdS3 can be
expressed in terms of Lambert's W-function. We compute the leading, subleading
and next-to-subleading series of exponential corrections to the infinite-volume
dispersion relation of GKP strings that rotate in RxS2. These strings are dual
to certain long operators of N=4 SYM theory and provide their scaling
dimensions at strong coupling. We also show that the strings obey a short-long
(strings) duality. For the folded GKP strings that spin inside AdS3 and are
dual to twist-2 operators, we confirm the known formulas for the leading and
next-to-leading coefficients of their anomalous dimensions and derive the
corresponding expressions for the next-to-next-to-leading coefficients.Comment: 46 pages, 8 figures; Matches published version; Contains equation
(7.3) that gives the finite-size corrections to the dispersion relation of
giant magnons at strong couplin
Assessing energy and thermal comfort of domestic buildings in the Mediterranean region
Nowadays, buildings are responsible for the 40% of energy consumption in the European Union, with energy up to 68% being coherent with thermal loads. Acknowledging the great potential of building sector, a substantial amount of the current building inventory must be refurbished, based on the trade-offs between energy and thermal comfort. To this effect, this study investigates the impact of retrofitting measures in residential envelope for areas experience Mediterranean climate. Seven detached houses, located in Cyprus, were modelled, investigating 253 parameters of envelope interventions and also, 7,056 combinations of these measures.
In general, the findings revealed a seasonal performance variation of interventions with regards to the outdoor climate. The application of roof insulation determined as the most economic viable solution during retrofitting (single interventions), achieving a reduction up to 25% of annual energy consumption with enhancement of the indoor thermal environment. In the perspective of synergies between interventions, the application of roof and external walls thermal insulation with upgrade of glazing system with double Low-E demonstrated exemplary levels of performance decreasing on average energy consumption up to 38%.The findings of this research will contribute on the development of guidelines for designers and house builders for a perceptual retrofitting of existing residential envelopes in Cyprus and also, for countries experiencing the Mediterranean climate
Increasing Motivation for Studying New Foreign Languages Using ICT : Introduction to Modern Greek
It is generally believed that motivation plays a significant role in foreign language learning; students who feel motivated to learn a foreign language are more likely to become successful learners. In Japan, where foreign language education has been primarily teacher-centered for years, students rarely get the opportunity to practice speaking or listening in class, and usually fare poorly at those skills. To provide an opportunity to increase motivation toward foreign languages, a Greek postgraduate student created teaching materials in PowerPoint and HTML to introduce the Greek language to a class of undergraduate students at Kyoto University. The students were asked to introduce themselves and then record their self-introductions using iPod nano(R) mobile digital devices distributed to them. This paper reports on the class content as well as the results of the questionnaire conducted at the end of the class
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