2,700 research outputs found
Investigation of Bose-Einstein Correlations in 3 jet events with the DELPHI detector
A preliminary investigation of Bose-Einstein correlations in 3 jet events has
been made by analysing the collected data at the peak from '94 and '95
and the calibration runs during the LEP2 period from '97 to 2000. Three methods
were used to extract two-particle correlation functions. No significant
difference was found between quark and gluon jets for all three methods.Comment: 6 pages, 2 figures in ps and 1 in eps, talk given at XXXI
International Symposium on Multiparticle Dynamics, Sept 1-7, 2001, Datong
China. see http://ismd31.ccnu.edu.cn
Casimir effect in a weak gravitational field and the spacetime index of refraction
In a recent paper [arXiv:0904.2904] using a conjecture it is shown how one
can calculate the effect of a weak stationary gravitational field on vacuum
energy in the context of Casimir effect in an external gravitational field
treated in 1+3 formulation of spacetime decomposition.. In this article,
employing quntum field theory in curved spacetime, we explicitly calculate the
effect of a weak static gravitational field on virtual massless scalar
particles in a Casimir apparatus. It is shown that, as expected from the
proposed conjecture, both the frequency and renormalized energy of the virtual
scalar field are affected by the gravitational field through its index of
refraction. This could be taken as a strong evidence in favour of the proposed
conjecture. Generalizations to weak {\it stationary} spacetimes and virtual
photons are also discussed.Comment: 11 pages, RevTex, typos corrected (combined with arXiv:0904.2904
published in PRD
An evaluation resource for geographic information retrieval
In this paper we present an evaluation resource for geographic information retrieval developed within the Cross Language Evaluation
Forum (CLEF). The GeoCLEF track is dedicated to the evaluation of geographic information retrieval systems. The resource
encompasses more than 600,000 documents, 75 topics so far, and more than 100,000 relevance judgments for these topics. Geographic
information retrieval requires an evaluation resource which represents realistic information needs and which is geographically
challenging. Some experimental results and analysis are reported
Revisiting Thymic Positive Selection and the Mature T Cell Repertoire for Antigen
To support effective host defense, the TÂ cell repertoire must balance breadth of recognition with sensitivity for antigen. The concept that T lymphocytes are positively selected in the thymus is well established, but how this selection achieves such a repertoire has not been resolved. Here we suggest that it is direct linkage between self and foreign antigen recognition that produces the necessary blend of TCR diversity and specificity in the mature peripheral repertoire, enabling responses to a broad universe of unpredictable antigens while maintaining an adequate number of highly sensitive TÂ cells in a population of limited size. Our analysis also helps to explain how diversity and frequency of antigen-reactive cells in a TÂ cell repertoire are adjusted in animals of vastly different size scale to enable effective antipathogen responses and suggests a possible binary architecture in the TCR repertoire that is divided between germline-related optimal binding and diverse recognition
GeoCLEF 2007: the CLEF 2007 cross-language geographic information retrieval track overview
GeoCLEF ran as a regular track for the second time within the Cross
Language Evaluation Forum (CLEF) 2007. The purpose of GeoCLEF is to test
and evaluate cross-language geographic information retrieval (GIR): retrieval
for topics with a geographic specification. GeoCLEF 2007 consisted of two sub
tasks. A search task ran for the third time and a query classification task was
organized for the first. For the GeoCLEF 2007 search task, twenty-five search
topics were defined by the organizing groups for searching English, German,
Portuguese and Spanish document collections. All topics were translated into
English, Indonesian, Portuguese, Spanish and German. Several topics in 2007
were geographically challenging. Thirteen groups submitted 108 runs. The
groups used a variety of approaches. For the classification task, a query log
from a search engine was provided and the groups needed to identify the
queries with a geographic scope and the geographic components within the
local queries
SzĂnházi nevelĂ©s Ă©s közönsĂ©gnevelĂ©s a Kaposvári Egyetemen
A tanulmány elsĹ‘ rĂ©szĂ©ben a kaposvári Csiky Gergely SzĂnház gyermek-, beavatĂł Ă©s iskolaszĂnházi hagyományait mutatom be. ÉrintĹ‘legesen szĂł esik a tágabb rĂ©giĂł beavatĂł szĂnházi elĹ‘zmĂ©nyeirĹ‘l, modelljeirĹ‘l, ezen belĂĽl a kaposvári szĂnház rĂ©giĂłbeli szerepĂ©rĹ‘l is. Az ismertetĂ©sben bemutatásra kerĂĽl az a gyermekszĂnházi műsorkoncepciĂł, amely a kaposvári rendezĹ‘egyĂ©nisĂ©gek egyĂ©ni művĂ©szi törekvĂ©seit, formakĂsĂ©rleteit is tĂĽkrözi. A törtĂ©neti áttekintĂ©sben szĂł esik NĂ©meth Antal szĂnház-pedagĂłgiájárĂłl, majd az 1970es, 1980-as, 1990-es Ă©vekben kibontakozĂł rendezĹ‘generáciĂłk gyermekszĂnházi nyelvĂ©rĹ‘l (pl. hogyan jelentek meg a tudatos közönsĂ©gnevelĹ‘ törekvĂ©sek az elĹ‘adások látványvilágának elemeiben, az elĹ‘adások szöveges Ă©s metakommunikatĂv utalásrendszerĂ©ben stb.), valamint a kaposvári gyermek-, Ă©s ifjĂşsági közönsĂ©ggel valĂł találkozási formáikrĂłl. A visszatekintĂ©sben hangsĂşlyt kap az a dĂ©l-dunántĂşli mikrokörnyezet is, amelyben ezek a gyermekszĂnházi tradĂciĂłk, illetve a közönsĂ©gnevelĂ©s Ă©vtizedek alatt formálĂłdott metodikája meggyökeresedhetett. A tanulmány második rĂ©szĂ©ben a közelmĂşlt Ă©s a jelen alkotĂłi szándĂ©kai kerĂĽlnek bemutatásra, valamint azok az egyĂĽttműködĂ©si formák, amelyek keretĂ©ben a szĂnházi alkotĂłk az egyetemi oktatĂłkkal karöltve egyetemi kurzusok keretĂ©ben ismertetik meg a hallgatĂłkkal a kĂĽlönbözĹ‘ gyermek- Ă©s ifjĂşsági elĹ‘adások jelrendszerĂ©t. Az ismertetĂ©sben elsĹ‘sorban egyetemi elĹ‘adások Ă©s szemináriumok (SzĂnházi Ă©lmĂ©ny feldolgozása, KreatĂv alkotĂłműhely) tematikájának bemutatásán keresztĂĽl jelennek meg azok a modellek Ă©s feldolgozási formák, amelyek lehetĹ‘sĂ©get biztosĂtanak arra, hogy a hallgatĂłk mĂ©lyebben megismerjĂ©k egy szĂnházi elĹ‘adás hatáselemeit: látványelemek (jelmez, kellĂ©k, dĂszlet, fĂ©nyek), zenei elemek-szĂnpadi zörejek-csend, szĂnĂ©szi játĂ©k, rendezĹ‘i koncepciĂł stb. A közlemĂ©ny utolsĂł rĂ©szĂ©ben a KreatĂv alkotĂłműhely cĂmű kurzus nĂ©hány foglalkozásmodellje kerĂĽl bemutatásra, amelyekben a közös alkotĂłmunka keretĂ©ben, a mesĂ©k dramatizálása során sokfĂ©le elĹ‘adási technikával ismerkednek meg a hallgatĂłk, a tanult szĂnházi hatáselemekkel játszva, kĂsĂ©rletezve
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