4,281 research outputs found
production and elliptic flow in relativistic heavy-ion collisions
Using a two-component model for charmonium production, which includes
contributions from both the initial hard nucleon-nucleon scattering and from
the regeneration in the quark-gluon plasma, we study the nuclear modification
factor and elliptic flow of in relativistic heavy ion
collisions. For the expansion dynamics of produced hot dense matter, we
introduce a schematic fireball model with its transverse acceleration
determined from the pressure gradient inside the fireball and azimuthally
anisotropic expansion parameterized to reproduce measured of light
hadrons. We assume that light hadrons freeze out at the temperature of 120 MeV
while charmonia at 160 MeV, similar to the kinetic and chemical freeze-out
temperatures in the statistical model, respectively. For the properties of
charmonia in the quark-gluon plasma, we use the screening mass between their
charm and anticharm quarks and their dissociation cross sections given by the
perturbative QCD (pQCD) in the leading order and up to the next-to-leading
order, respectively. For the relaxation time of charm and anticharm quarks in
the quark-gluon plasma, we also use the one calculated in the leading order of
pQCD. Modeling the effect of higher-order corrections in pQCD by introducing
multiplicative factors to the dissociation cross section of charmonia and the
elastic scattering cross sections of charm and anticharm quarks, we find that
this effect is small for the of as they suppress the number
of initially produced but enhance the number of regenerated ones. The
higher-order corrections increase, however, the of . Our results
suggest that the of can play an important role in discriminating
between production from the initial hard collisions and from the
regeneration in the quark-gluon plasma.Comment: 15 pages, 14 figure
RFID Information Value Chain and ETRI RFID Ecosystem: Value-added Environment Linking Physical and Virtual Worlds
Case Study on the Enterprise Microblog Usage: Focusing on Knowledge Learning
Knowledge Management Strategy can be classified by codification strategy and personalization strategy (Hansen et. al., 1999), and how to manage the two strategies were always studied. Also, current studies regarding the knowledge management strategy were targeted mostly for major companies, resulting in lack of studies in how it can be applied on SMEs. This research, with the knowledge management strategy suited for SMEs, sets an Enterprise Microblog (EMB), and with the EMB applied on SMEs’ Knowledge Management Strategy, it is reviewed on the perspective of SMEs’ Codification and Personalization Strategies. Through the advanced research regarding Knowledge Management Strategy and EMB, the hypothesis is set that “Depending on the development of the company, the main application of EMB alters from Codification Strategy to Personalization Strategy.” To check the hypothesis, SME that have used the EMB called ‘Yammer’ was analyzed from the data of their foundation until today. The case study has implemented longitudinal analysis which divides the period when the EMBs were used into three stages and analyzes the contents. As the result of the study, this suggests a substantial implication regarding the application of Knowledge Management Strategy and its Knowledge Management System that is suitable for SME
Port Selection Criteria for the Korea-China Train Ferry
The Korea-China Train Ferry can be one option to enter into Eurasia and a meaningful way to extend the route forlogistics enterprise and manufacturers of Korea to reach the broaderglobal marketalong with specific access to China. Under this scenaris, this study is designed to look at the progress and status of the Korea-China Train Ferry project as anopportunity for Korea to build a path towards Eurasia and to review factors and opinions to consider in port selectionbased on in-depth interviewswith industry participants andexperts. It alsoaims to discuss ideas for a Korea-Chinalogistics cooperative system. For the train ferry's success, agreements between Korea and China are essential to ensure consistency inbase ports and customsclearance procedures and long-term preparation should be made in the first phase to build the framework for the Korea-China Train Ferry operations
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