2,767 research outputs found
The foreign exchange market: return distributions, multifractality, anomalous multifractality and Epps effect
We present a systematic study of various statistical characteristics of
high-frequency returns from the foreign exchange market. This study is based on
six exchange rates forming two triangles: EUR-GBP-USD and GBP-CHF-JPY. It is
shown that the exchange rate return fluctuations for all the pairs considered
are well described by the nonextensive statistics in terms of q-Gaussians.
There exist some small quantitative variations in the nonextensivity
q-parameter values for different exchange rates and this can be related to the
importance of a given exchange rate in the world's currency trade. Temporal
correlations organize the series of returns such that they develop the
multifractal characteristics for all the exchange rates with a varying degree
of symmetry of the singularity spectrum f(alpha) however. The most symmetric
spectrum is identified for the GBP/USD. We also form time series of triangular
residual returns and find that the distributions of their fluctuations develop
disproportionately heavier tails as compared to small fluctuations which
excludes description in terms of q-Gaussians. The multifractal characteristics
for these residual returns reveal such anomalous properties like negative
singularity exponents and even negative singularity spectra. Such anomalous
multifractal measures have so far been considered in the literature in
connection with the diffusion limited aggregation and with turbulence. We find
that market inefficiency on short time scales leads to the occurrence of the
Epps effect on much longer time scales. Although the currency market is much
more liquid than the stock markets and it has much larger transaction
frequency, the building-up of correlations takes up to several hours - time
that does not differ much from what is observed in the stock markets. This may
suggest that non-synchronicity of transactions is not the unique source of the
observed effect
Quantitative features of multifractal subtleties in time series
Based on the Multifractal Detrended Fluctuation Analysis (MFDFA) and on the
Wavelet Transform Modulus Maxima (WTMM) methods we investigate the origin of
multifractality in the time series. Series fluctuating according to a qGaussian
distribution, both uncorrelated and correlated in time, are used. For the
uncorrelated series at the border (q=5/3) between the Gaussian and the Levy
basins of attraction asymptotically we find a phase-like transition between
monofractal and bifractal characteristics. This indicates that these may solely
be the specific nonlinear temporal correlations that organize the series into a
genuine multifractal hierarchy. For analyzing various features of
multifractality due to such correlations, we use the model series generated
from the binomial cascade as well as empirical series. Then, within the
temporal ranges of well developed power-law correlations we find a fast
convergence in all multifractal measures. Besides of its practical significance
this fact may reflect another manifestation of a conjectured q-generalized
Central Limit Theorem
Jets as a Probe of Dense Matter at RHIC
Jet quenching in the matter created in high energy nucleus-nucleus collisions
provides a tomographic tool to probe the medium properties. Recent experimental
results on jet production at the Relativistic Heavy-Ion Collider (RHIC) are
reviewed. Jet properties in p+p and d+Au collisions have been measured,
establishing the baseline for studying jet modification in heavy-ion
collisions. Current progress on detailed studies of high transverse momentum
production in Au+Au collisions is discussed, with an emphasis on dihadron
correlation measurements.Comment: 8 pages, 9 figures. Plenary talk given at 17th International
Conference on Ultra Relativistic Nucleus-Nucleus Collisions (Quark Matter
2004), Oakland, California, 11-17 Jan 2004. Submitted to J.Phys.
A Large Cross-Sectional Study of Health Attitudes, Knowledge, Behaviour and Risks in the Post-War Croatian Population (The First Croatian Health Project*)
As the liberation of occupied Croatian territories ended the war in the country in
1995, the Ministry of Health and Croatian Health Insurance Institute have agreed to
create the new framework for developing a long-term strategy of public health planning,
prevention and intervention. They provided financial resources to develop the First Cro-atian Health Project, the rest of the support coming from the World Bank loan and the
National Institute of Public Health. A large cross-sectional study was designed aiming
to assess health attitudes, knowledge, behaviour and risks in the post-war Croatian
population. The large field study was carried out by the Institute for Anthropological
Research with technical support from the National Institute of Public Health. The field
study was completed between 1995–1997. It included about 10,000 adult volunteers
from all 21 Croatian counties. The geographic distribution of the sample covered both
coastal and continental areas of Croatia and included rural and urban environments.
The specific measurements included antropometry (body mass index and blood pressure).
From each examinee a blood sample was collected from which the levels of total
plasma cholesterol (TC), triglycerides (TG), HDL-cholesterol (High Density Lipoprotein),
LDL-cholesterol (Low Density Lipoprotein), lipoprotein Lp(a), and haemostatic
risk factor fibrinogen (F) were determined. The detailed data were collected on the general
knowledge and attitudes on health issues, followed by specific investigation of
smoking history, alcohol consumption, nutrition habits, physical activity, family history
of chronic non-communicable diseases and occupational exposures. From the initial database
a targeted sample of 5,840 persons of both sexes, aged 18–65, was created corresponding
by age, sex and geographic distribution to the general Croatian population.
This paper summarises and discusses the main findings of the project within this representative
sample of Croatian population
The future of Cybersecurity in Italy: Strategic focus area
This volume has been created as a continuation of the previous one, with the aim of outlining a set of focus areas and actions that the Italian Nation research community considers essential. The book touches many aspects of cyber security, ranging from the definition of the infrastructure and controls needed to organize cyberdefence to the actions and technologies to be developed to be better protected, from the identification of the main technologies to be defended to the proposal of a set of horizontal actions for training, awareness raising, and risk management
РОЗРОБКА МОДЕЛІ ОРГАНІЗАЦІЙНОЇ СТРУКТУРИ ВИЩОГО НАВЧАЛЬНОГО ЗАКЛАДУ ЗАСОБАМИ СИСТЕМИ УПРАВЛІННЯ ПРОЕКТАМИ «МЕГАПЛАН»
A scientific problem of developing the model of higher education institution organizational structure for example Lviv State Universi ty of Vital Activity Safety is considered in the article. Informational and literary analysis of the use of project and processes management systems in large organizations is carried out. The model of organizational structure of Lviv State University of Vi tal Activity Safety is developed in the project management system "Megaplan". The approaches to optimize the operating activities of the university with usage of project-oriented management are suggested.В статті розглядається наукова задача розробки моделі організаційної структури вищого навчального закладу на прикладі Львівського державного університету безпеки життєдіяльності. Проведено інформаційний та літературний аналіз використання систем управління проектами та процесами в великих організаціях. Розроблено модель організаційної структури Львівського державного університету безпеки життєдіяльності в системі управління проектами «Мегаплан». Запропоновані підходи до оптимізації операційної діяльності університету з використанням проектно-орієнтованого управління
The Suppressor of AAC2 Lethality SAL1 Modulates Sensitivity of Heterologously Expressed Artemia ADP/ATP Carrier to Bongkrekate in Yeast
The ADP/ATP carrier protein (AAC) expressed in Artemia franciscana is refractory to bongkrekate. We generated two strains of Saccharomyces cerevisiae where AAC1 and AAC3 were inactivated and the AAC2 isoform was replaced with Artemia AAC containing a hemagglutinin tag (ArAAC-HA). In one of the strains the suppressor of ΔAAC2 lethality, SAL1, was also inactivated but a plasmid coding for yeast AAC2 was included, because the ArAACΔsal1Δ strain was lethal. In both strains ArAAC-HA was expressed and correctly localized to the mitochondria. Peptide sequencing of ArAAC expressed in Artemia and that expressed in the modified yeasts revealed identical amino acid sequences. The isolated mitochondria from both modified strains developed 85% of the membrane potential attained by mitochondria of control strains, and addition of ADP yielded bongkrekate-sensitive depolarizations implying acquired sensitivity of ArAAC-mediated adenine nucleotide exchange to this poison, independent from SAL1. However, growth of ArAAC-expressing yeasts in glycerol-containing media was arrested by bongkrekate only in the presence of SAL1. We conclude that the mitochondrial environment of yeasts relying on respiratory growth conferred sensitivity of ArAAC to bongkrekate in a SAL1-dependent manner. © 2013 Wysocka-Kapcinska et al
Interferometry of Direct Photons in Central 280Pb+208Pb Collisions at 158A GeV
Two-particle correlations of direct photons were measured in central
208Pb+208Pb collisions at 158 AGeV. The invariant interferometric radii were
extracted for 100<K_T<300 MeV/c and compared to radii extracted from charged
pion correlations. The yield of soft direct photons, K_T<300 MeV/c, was
extracted from the correlation strength and compared to theoretical
calculations.Comment: 5 pages, 4 figure
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