115 research outputs found
An efficient algorithm simulating a macroscopic system at the critical point
It is well known that conventional simulation algorithms are inefficient for
the statistical description of macroscopic systems exactly at the critical
point due to the divergence of the corresponding relaxation time (critical
slowing down). On the other hand the dynamics in the order parameter space is
simplified significantly in this case due to the onset of self-similarity in
the associated fluctuation patterns. As a consequence the effective action at
the critical point obtains a very simple form. In the present work we show that
this simplified action can be used in order to simulate efficiently the
statistical properties of a macroscopic system exactly at the critical point.
Using the proposed algorithm we generate an ensemble of configurations
resembling the characteristic fractal geometry of the critical system related
to the self-similar order parameter fluctuations. As an example we simulate the
one-component real scalar field theory at the transition point as a
representative system belonging to the Ising universality class.Comment: 10 pages, 6 figures, submitted for publication to Journal of
Computational Physic
Publications in Vascular Journals: Contribution by Country
The geographical origin of all published papers in four major vascular journals as well as the “vascular papers” in two high impact “general” surgical journals during a four year period (2003-2006) were examined by search of their electronic editions. As an index of high quality papers, the randomized controlled trials (RCT's) by country were also examined. A total of 3422 papers were searched in the four vascular journals (115 RCT's) while 144 “vascular” papers (19 RCT's) were located in the two “general” surgical journals. It was not surprising that USA and western European countries were having the largest contribution to the vascular literature
Complementarity in classical dynamical systems
The concept of complementarity, originally defined for non-commuting
observables of quantum systems with states of non-vanishing dispersion, is
extended to classical dynamical systems with a partitioned phase space.
Interpreting partitions in terms of ensembles of epistemic states (symbols)
with corresponding classical observables, it is shown that such observables are
complementary to each other with respect to particular partitions unless those
partitions are generating. This explains why symbolic descriptions based on an
\emph{ad hoc} partition of an underlying phase space description should
generally be expected to be incompatible. Related approaches with different
background and different objectives are discussed.Comment: 18 pages, no figure
Pion emission from the T2K replica target: method, results and application
The T2K long-baseline neutrino oscillation experiment in Japan needs precise
predictions of the initial neutrino flux. The highest precision can be reached
based on detailed measurements of hadron emission from the same target as used
by T2K exposed to a proton beam of the same kinetic energy of 30 GeV. The
corresponding data were recorded in 2007-2010 by the NA61/SHINE experiment at
the CERN SPS using a replica of the T2K graphite target. In this paper details
of the experiment, data taking, data analysis method and results from the 2007
pilot run are presented. Furthermore, the application of the NA61/SHINE
measurements to the predictions of the T2K initial neutrino flux is described
and discussed.Comment: updated version as published by NIM
The Greek Connection(s): The Social Organization of the Cigarette-Smuggling Business in Greece
Some aspects of the Liouville equation in mathematical physics and statistical mechanics
This paper presents some mathematical aspects of Classical Liouville theorem
and we have noted some mathematical theorems about its initial value problem.
Furthermore, we have implied on the formal frame work of Stochastic Liouville
equation (SLE)
A new SPS programme
A new experiemntal program to study hadron production in hadron-nucleus and nucleus-nucleus collisions at the CERN SPS has been recently proposed by the NA49-future collaboration. The physics goals of the program are: (i) search for the critical point of strongly interacting matter and a study of the properties of the onset of deconfinemnt in nucleus-nucleus collisions, (ii) measurements of correlations, fluctuations and hadron spectra at high transverse momentum in proton-nucleus collisions needed as for better understanding of nucleus-nucleus results, (iii) measurements of hadron production in hadron-nucleus interactions needed for neutrino (T2K) and cosmic-ray (Pierre Auger Observatory and KASCADE) expriments. The physics of the nucleus-nucleus program is reviewed in this presentation
The interplay of KRAS mutational status with tumor laterality in non-metastatic colorectal cancer: An international, multi-institutional study in patients with known KRAS, BRAF, and MSI status
Background: Although the prognostic relevance of KRAS status in metastatic colorectal cancer (CRC) depends on tumor laterality, this relationship is largely unknown in non-metastatic CRC. Methods: Patients who underwent resection for non-metastatic CRC between 2000 and 2018 were identified from institutional databases at six academic tertiary centers in Europe and Japan. The prognostic relevance of KRAS status in patients with right-sided (RS), left-sided (LS), and rectal cancers was assessed. Results: Of the 1093 eligible patients, 378 had right-sided tumors and 715 had left-sided tumors. Among patients with RS tumors, the 5-year overall (OS) and recurrence-free survival (RFS) for patients with KRASmut versus wild-type tumors was not shown to differ significantly (82.2% vs. 83.2% and 72.1% vs. 76.7%, respectively, all p >.05). Among those with LS tumors, KRAS mutation was associated with shorter 5-year OS and RFS on both the univariable (OS: 79.4% vs. 86.1%, p =.004; RFS: 68.8% vs. 77.3%, p =.005) and multivariable analysis (OS: HR: 1.52, p =.019; RFS: HR: 1.32, p =.05). Conclusions: KRAS mutation status was independently prognostic among patients with LS tumors, but this association failed to reach statistical significance in RS and rectal tumors. These findings confirm reports in metastatic CRC and underline the possible biologic importance of tumor location
Search for the QCD critical point at SPS energies
Lattice QCD calculations locate the QCD critical point at energies accessible at the CERN Super Proton Synchrotron (SPS). We present average transverse momentum and multiplicity fluctuations, as well as baryon and anti-baryon transverse mass spectra which are expected to be sensitive to effects of the critical point. The future CP search strategy of the NA61/SHINE experiment at the SPS is also discussed.Lattice QCD calculations locate the QCD critical point at energies accessible at the CERN Super Proton Synchrotron (SPS). We present average transverse momentum and multiplicity fluctuations, as well as baryon and anti-baryon transverse mass spectra which are expected to be sensitive to effects of the critical point. The future CP search strategy of the NA61/SHINE experiment at the SPS is also discussed
论创业投资中的风险控制
创业投资是资本市场培育高新技术产业的一种创新的制度安排,有别于一般的投资活动。由于被投资企业的不确定性、交易中信息的高度不对称及投资参与方以外的因素,使得创业投资在获得高收益回报的同时,要承担比一般投资活动大得多的风险,高风险是其核心特征。对风险的有效控制成为创业投资成功获得预期收益的关键。在我国目前这种环境下,由于经济体制和市场机制的缺陷,创业投资蕴含的风险更大,更有必要强调风险控制。全文共分三章,主要内容如下: 第一章比较创业投资与一般投资的主要区别,阐明创业投资风险的特殊性和风险控制的重点。 第二章这是文章的重点,针对创业投资的三个风险来源:被投资企业的不确定性、交易中信息的高度不对...学位:经济学硕士院系专业:经济学院经济系_政治经济学学号:19980900
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