Alternative measure of multifractal content and its application in finance

International Nuclear Information System (INIS)

Grech, Dariusz

2016-01-01

An alternative method for analysis of multifractal properties of time series is provided. We propose a new kind of measure of multifractality strength which takes into account the behavior of multifractal profile of the generalized Hurst exponent h(q) for all moment orders q and is not limited only to the edge values of moment orders describing the scaling properties of smallest and largest fluctuations of a given signal in multifractal detrended fluctuation analysis (MFDFA). The meaning of this new measure is clarified and its performance is investigated for synthetic multifractal data and also for examples of real signals originating from stock markets. We provide also the interpretation of the alternative method following the scaling law that links together the geometric mean value of properly normalized standard q-fluctuation function F"2(q; τ) in MFDFA and the window length τ in which detrending of a signal is performed. We discuss in this context the influence of multifractal bias on the new measure, i.e., the influence of effects which give similar observed features as multiscaling properties however, are not generated by temporal multiscaling autocorrelation in data. It is shown that the proposed alternative measure is robust in some extend to nonstationarity in data. As a result one may avoid problems with interpretation of multifractal profile h(q) encountered in many real nonstationary signals investigated in the standard way.

MULTIFRACTAL STRUCTURE OF CENTRAL AND EASTERN EUROPEAN FOREIGN EXCHANGE MARKETS

Directory of Open Access Journals (Sweden)

Cn#259;pun#351;an Rn#259;zvan

2012-07-01

Full Text Available It is well known that empirical data coming from financial markets, like stock market indices, commodities, interest rates, traded volumes and foreign exchange rates have a multifractal structure. Multifractals were introduced in the field of economics to surpass the shortcomings of classical models like the fractional Brownian motion or GARCH processes. In this paper we investigate the multifractal behavior of Central and Eastern European foreign exchange rates, namely the Czech koruna, Croatian kuna, Hungarian forint, Polish zlot, Romanian leu and Russian rouble with respect to euro from January 13, 2000 to February 29, 2012. The dynamics of exchange rates is of interest for investors and traders, monetary and fiscal authorities, economic agents or policy makers. The exchange rate movements affect the international balance of payments, trade flows, and allocation of the resources in national and international economy. The empirical results from the multifractal detrending fluctuation analysis algorithm show that the six exchange rate series analysed display significant multifractality. Moreover, generating shuffled and surrogate time series, we analyze the sources of multifractality, long-range correlations and heavy-tailed distributions, and we find that this multifractal behavior can be mainly attributed to the latter. Finally, we propose a foreign exchange market inefficiency ranking by considering the multifractality degree as a measure of inefficiency. The regulators, through policy instruments, aim to improve the informational inefficiency of the markets, to reduce the associated risks and to ensure economic stabilization. Evaluation of the degree of information efficiency of foreign exchange markets, for Central and Eastern Europe countries, is important to assess to what extent these countries are prepared for the transition towards fully monetary integration. The weak form efficiency implies that the past exchange rates cannot help to

Approaching the empowerment of roma women: an analysis from an intersectional view

Directory of Open Access Journals (Sweden)

Uxue Zugaza Goienetxea

2017-06-01

Full Text Available This paper focuses on the process of empowerment of roma women. Considering the intersection of inequalities that they face, the article points out that an analytical turn of these processes is needed in order to approach them from an intersectional view. In this context, the introduction of this perspective in the consideration of the empowerment of roma women is seen as a necessary step in order to inspire and rethink the democratization in terms of recognition of this collective. The article tackles the following question then: what does intersectionality tell about the empowerment of roma women? With this objective, the text discusses the life’s testimonies of five roma women collected through in-depth interviews. Through the analysis of the tensions emerging during their processes of empowerment, the paper concludes with some proposals in order to overcome these obstacles.

Multifractal properties of resistor diode percolation.

Science.gov (United States)

Stenull, Olaf; Janssen, Hans-Karl

2002-03-01

Focusing on multifractal properties we investigate electric transport on random resistor diode networks at the phase transition between the nonpercolating and the directed percolating phase. Building on first principles such as symmetries and relevance we derive a field theoretic Hamiltonian. Based on this Hamiltonian we determine the multifractal moments of the current distribution that are governed by a family of critical exponents [psi(l)]. We calculate the family [psi(l)] to two-loop order in a diagrammatic perturbation calculation augmented by renormalization group methods.

Social support, hopelessness and life satisfaction among Roma and non-Roma adolescents in Slovakia

NARCIS (Netherlands)

Kolarcik, P.; Geckova, A. Madarasova; Reijneveld, S. A.; van Dijk, J. P.

2012-01-01

Evidence on the psychosocial determinants of health among Roma adolescents is completely lacking. Our aim was to compare social support, life satisfaction and hopelessness of Slovak Roma and non-Roma adolescents and to assess the impact of parental education and social desirability on these

Thermodynamic and multifractal formalism and the Bowen-series map

International Nuclear Information System (INIS)

Rudolph, O.

1995-01-01

In the theory of quantum chaos one studies the semiclassical behaviour of quantum mechanical systems whose corresponding classical counterparts exhibit chaos. The geodesic motion of a free classical particle on closed Riemann surfaces with constant negative curvature is strongly chaotic. Selberg's theory relates the classical and the quantum mechanical systems. These systems are sometimes considered as model systems in the theory of quantum chaos since they are well understood from a mathematical point of view. In this work we study the multifractal formalism for the geodesic flow on surfaces with constant negative curvature. The multifractal analysis of measures has been developed in order to characterize the scaling behaviour of measures on attractors of classical chaotic dynamical systems globally. In order to relate the multifractal formalism with quantities usually considered in the study of the geodesic flow on Riemann surfaces with constant negative curvature, it is necessary to establish the assertions of the multifractal formalism in a mathematically rigorous way. This is achieved with the help of the thermodynamic formalism for hyperbolic dynamical systems developed by Ruelle, Bowen and others. (orig.)

Roma Identity as an Expert-Political Construction

Directory of Open Access Journals (Sweden)

Mihai Surdu

2015-09-01

Full Text Available The creation of an EU Framework for national Roma integration strategies (2011 marks a significant step in the politicisation of Roma identity by ensuring a further increase in the number of initiatives, projects and programmes explicitly targeting Roma. The Framework itself is part of a process that began with postcommunist transition and which has produced historically unprecedented levels of Roma political activism along with a proliferation of national and transnational policy initiatives focussed on Roma identity. In seeking to explain this contemporary political phenomenon, the article argues that Roma is an identity constructed at the intersection of political and expert knowledge by various actors, such as policymakers, Romani activists, international organizations and scholars. This political-expert identity is applied to groups that are not bounded by a common language, religion, cultural practice, geographic location, occupation, physical appearance or lifestyle. The article explores how this collation of disparate populations into a notional political community builds upon a centuries-old Gypsy legacy. It scrutinizes five strands of identification practices that have contributed to the longue durée development of today’s Roma as an epistemic object and policy target: police profiling of particular communities; administrative surveys; Romani activism; Roma targeted policies; quantitative scientific research. The article argues that the contemporary economic and political conditions amidst which the politicisation of Roma identity is occurring explain how the ideological and institutional construction of the ethnic frame tends toward the reinforcement of the exclusion of those categorised as Roma, thus increasing the perceived need for Roma policy initiatives. A self-sustaining cycle has been created where Roma knowledge identifies Roma problems requiring a policy response, which produces more Roma knowledge, more needs and more

Maximising information recovery from rank-order codes

Science.gov (United States)

Sen, B.; Furber, S.

2007-04-01

The central nervous system encodes information in sequences of asynchronously generated voltage spikes, but the precise details of this encoding are not well understood. Thorpe proposed rank-order codes as an explanation of the observed speed of information processing in the human visual system. The work described in this paper is inspired by the performance of SpikeNET, a biologically inspired neural architecture using rank-order codes for information processing, and is based on the retinal model developed by VanRullen and Thorpe. This model mimics retinal information processing by passing an input image through a bank of Difference of Gaussian (DoG) filters and then encoding the resulting coefficients in rank-order. To test the effectiveness of this encoding in capturing the information content of an image, the rank-order representation is decoded to reconstruct an image that can be compared with the original. The reconstruction uses a look-up table to infer the filter coefficients from their rank in the encoded image. Since the DoG filters are approximately orthogonal functions, they are treated as their own inverses in the reconstruction process. We obtained a quantitative measure of the perceptually important information retained in the reconstructed image relative to the original using a slightly modified version of an objective metric proposed by Petrovic. It is observed that around 75% of the perceptually important information is retained in the reconstruction. In the present work we reconstruct the input using a pseudo-inverse of the DoG filter-bank with the aim of improving the reconstruction and thereby extracting more information from the rank-order encoded stimulus. We observe that there is an increase of 10 - 15% in the information retrieved from a reconstructed stimulus as a result of inverting the filter-bank.

IDENTIFYING AND CHANGING STEREOTYPES BETWEEN ROMA AND NON-ROMA: FROM THEORY TO PRACTICE

Directory of Open Access Journals (Sweden)

Gregor Maučec

2013-09-01

Full Text Available Having shortly delineated and theoretically defined the concept of stereotypes (as collective social constructs and stereotyping as such, the author turns to much more complex issue as to how to identify and change stereotypes about Roma, which are deeply rooted in mainstream European societies where they live and also those stereotypes that are nurtured and strictly followed by the Roma and which relate to non-Roma. The author arrives at a conclusion that today one can note several factors and conditions in European countries which still nurture and further reinforce especially anti-Roma stereotypes. According to him, the specific and carefully elaborated stereotypes-oriented policies and strategies which favour mutual education, knowledge and understanding as well as ongoing contact and dialogue between the two different ethnic, social and cultural identities at both EU and member states levels are conditio sine qua non for the enhanced and overall Roma inclusion and integration.

Multifractals

International Nuclear Information System (INIS)

Amritkar, R.E.; Gupte, N.

1988-09-01

We review the framework set up for the multifractal analysis of self-similar sets. This framework provides a way of extracting the singular structure of the sets analysed and has proven to be useful in a wide variety of physical contexts. We discuss some of the diverse applications of the framework. The framework has also provided the basis for significant advances in the analysis of dynamical systems. We review various developments based on the multifractal framework. These include the thermodynamic formalism, the inverse problem and the framework required for partially self-similar sets. We discuss the consequences of these developments for the analysis of attractors of systems on the border-line of chaos and give an outline of the developing field of the analysis of chaotic attractors. A brief account of other developments like the effect of fluctuations and the renormalization group analysis of multifractals is also provided. (author). 111 refs, 9 figs, 2 tabs

Distinguishing cognitive state with multifractal complexity of hippocampal interspike interval sequences

Directory of Open Access Journals (Sweden)

Dustin eFetterhoff

2015-09-01

Full Text Available Fractality, represented as self-similar repeating patterns, is ubiquitous in nature and the brain. Dynamic patterns of hippocampal spike trains are known to exhibit multifractal properties during working memory processing; however, it is unclear whether the multifractal properties inherent to hippocampal spike trains reflect active cognitive processing. To examine this possibility, hippocampal neuronal ensembles were recorded from rats before, during and after a spatial working memory task following administration of tetrahydrocannabinol (THC, a memory-impairing component of cannabis. Multifractal detrended fluctuation analysis was performed on hippocampal interspike interval sequences to determine characteristics of monofractal long-range temporal correlations (LRTCs, quantified by the Hurst exponent, and the degree/magnitude of multifractal complexity, quantified by the width of the singularity spectrum. Our results demonstrate that multifractal firing patterns of hippocampal spike trains are a marker of functional memory processing, as they are more complex during the working memory task and significantly reduced following administration of memory impairing THC doses. Conversely, LRTCs are largest during resting state recordings, therefore reflecting different information compared to multifractality. In order to deepen conceptual understanding of multifractal complexity and LRTCs, these measures were compared to classical methods using hippocampal frequency content and firing variability measures. These results showed that LRTCs, multifractality, and theta rhythm represent independent processes, while delta rhythm correlated with multifractality. Taken together, these results provide a novel perspective on memory function by demonstrating that the multifractal nature of spike trains reflects hippocampal microcircuit activity that can be used to detect and quantify cognitive, physiological and pathological states.

Linearization effect in multifractal analysis: Insights from the Random Energy Model

Science.gov (United States)

Angeletti, Florian; Mézard, Marc; Bertin, Eric; Abry, Patrice

2011-08-01

The analysis of the linearization effect in multifractal analysis, and hence of the estimation of moments for multifractal processes, is revisited borrowing concepts from the statistical physics of disordered systems, notably from the analysis of the so-called Random Energy Model. Considering a standard multifractal process (compound Poisson motion), chosen as a simple representative example, we show the following: (i) the existence of a critical order q∗ beyond which moments, though finite, cannot be estimated through empirical averages, irrespective of the sample size of the observation; (ii) multifractal exponents necessarily behave linearly in q, for q>q∗. Tailoring the analysis conducted for the Random Energy Model to that of Compound Poisson motion, we provide explicative and quantitative predictions for the values of q∗ and for the slope controlling the linear behavior of the multifractal exponents. These quantities are shown to be related only to the definition of the multifractal process and not to depend on the sample size of the observation. Monte Carlo simulations, conducted over a large number of large sample size realizations of compound Poisson motion, comfort and extend these analyses.

Romanian Roma: An Institutional Ethnography of Labour Market Exclusion

Directory of Open Access Journals (Sweden)

Janne Paulsen Breimo

2016-02-01

Full Text Available Roma individuals are struggling to access the formal labour market in Romania. Previous research occupied with this issue has traditionally been dominated by quantitative studies of socio-economic indicators that cling to the characteristics of the ethnic group. The study presented here, however, uses institutional ethnography as a method of social inquiry to demonstrate that this issue needs to be studied from a bottom-up perspective. The article illustrates that there are factors connected to how the system of occupational integration operates that must be taken into consideration in order to explain the difficulties Roma individuals face when trying to enter the labour market in Romania. We argue that these structural barriers create and reinforce processes of minoritising that increase marginalization and discrimination and thereby hinder work inclusion for Roma individuals.

Immigration of Roma from Republic of Serbia

Directory of Open Access Journals (Sweden)

Tatjana Vukelić

2013-02-01

Full Text Available The questions of immigration are topics of high interest for the contemporary migration studies. Particularly relevant for the Western European countries is the immigration of Roma. This study analyzes the case of Roma asylum-seekers from Republic of Serbia to Federal Republic of Germany, which assumed a new dimension following the visa liberation. Focus of this article are the links among the social, economical, transitional and political conditions of Roma asylum-seeking, as well as an analysis of potential networks and knowledge transfer among Roma. In particular is to be understand if there is any transnational networking between Roma in home countries and abroad as well if Roma asylum-seekers have to be seen as perpetrators or rather victims of the political occurrences in the concerning country.

Measuring efficiency of international crude oil markets: A multifractality approach

Science.gov (United States)

Niere, H. M.

2015-01-01

The three major international crude oil markets are treated as complex systems and their multifractal properties are explored. The study covers daily prices of Brent crude, OPEC reference basket and West Texas Intermediate (WTI) crude from January 2, 2003 to January 2, 2014. A multifractal detrended fluctuation analysis (MFDFA) is employed to extract the generalized Hurst exponents in each of the time series. The generalized Hurst exponent is used to measure the degree of multifractality which in turn is used to quantify the efficiency of the three international crude oil markets. To identify whether the source of multifractality is long-range correlations or broad fat-tail distributions, shuffled data and surrogated data corresponding to each of the time series are generated. Shuffled data are obtained by randomizing the order of the price returns data. This will destroy any long-range correlation of the time series. Surrogated data is produced using the Fourier-Detrended Fluctuation Analysis (F-DFA). This is done by randomizing the phases of the price returns data in Fourier space. This will normalize the distribution of the time series. The study found that for the three crude oil markets, there is a strong dependence of the generalized Hurst exponents with respect to the order of fluctuations. This shows that the daily price time series of the markets under study have signs of multifractality. Using the degree of multifractality as a measure of efficiency, the results show that WTI is the most efficient while OPEC is the least efficient market. This implies that OPEC has the highest likelihood to be manipulated among the three markets. This reflects the fact that Brent and WTI is a very competitive market hence, it has a higher level of complexity compared against OPEC, which has a large monopoly power. Comparing with shuffled data and surrogated data, the findings suggest that for all the three crude oil markets, the multifractality is mainly due to long

Stigma Consciousness in the case of Romanian Roma Activists

Directory of Open Access Journals (Sweden)

Laura SURDU

2013-11-01

Full Text Available Roma people are often stigmatized by the members of the out-groups, the process of stigmatization being enforced through a selection of stereotypically assigned characteristics of the group. In the last two decades, the stigmatization of Roma was contributed by scientists, policy makers and mass media. Stigma is a basis for social exclusion of Roma people and it is transferred from the whole group to the individual level. The negative labelling of the entire Roma group affects identity and stigma consciousness for each individual Roma. This paper addresses ethnic stigma consciousness in a sample of 96 Roma activists, women and men. The results show that stigma consciousness is highly present among Roma participants from the sample, although there are not significant differences between Roma women and Roma men regarding ethnic stigma consciousness.

Weyl and Riemann-Liouville multifractional Ornstein-Uhlenbeck processes

International Nuclear Information System (INIS)

Lim, S C; Teo, L P

2007-01-01

This paper considers two new multifractional stochastic processes, namely the Weyl multifractional Ornstein-Uhlenbeck process and the Riemann-Liouville multifractional Ornstein-Uhlenbeck process. Basic properties of these processes such as locally self-similar property and Hausdorff dimension are studied. The relationship between the multifractional Ornstein-Uhlenbeck processes and the corresponding multifractional Brownian motions is established

Multifractal cross-correlations between crude oil and tanker freight rate

Science.gov (United States)

Chen, Feier; Miao, Yuqi; Tian, Kang; Ding, Xiaoxu; Li, Tingyi

2017-05-01

Analysis of crude oil price and tanker freight rate volatility attract more attention as the mechanism is not only the basis of industrialization but also a vital role in economics, especially after the year 2008 when financial crisis notably blew the maritime transportation. In this paper, we studied the cross-correlations between the West Texas International crude oil (WTI) and Baltic Exchange Dirty Tanker Index (BDTI) employing the Multifractal Detrended Cross-Correlation Analysis (MF-DCCA). Empirical results show that the degree of short-term cross-correlation is higher than that in the long term and that the strength of multifractality after financial crisis is larger than that before. Moreover, the components of multifractal spectrum are quantified with the finite-size effect taken into consideration and an improved method in terms of constructing the surrogated time series provided. Numerical results show that the multifractality is generated mostly from the nonlinear and the fat-tailed probability distribution (PDF) part. Also, it is apparent that the PDF part changes a lot after the financial crisis. The research is contributory to risk management by providing various instructions for participants in shipping markets. Our main contribution is that we investigated both the multifractal features and the origin of multifractality and provided confirming evidence of multifractality through numerical results while applying quantitative analysis based on MF-DCCA; furthermore, the research is contributory to risk management since it provides instructions in both economic market and stock market simultaneously. However, constructing the surrogated series in order to obtain consistence seems less convincing which requires further discussion and attempts.

Lorentz violations in multifractal spacetimes

Energy Technology Data Exchange (ETDEWEB)

Calcagni, Gianluca [Instituto de Estructura de la Materia, CSIC, Madrid (Spain)

2017-05-15

Using the recent observation of gravitational waves (GW) produced by a black-hole merger, we place a lower bound on the energy above which a multifractal spacetime would display an anomalous geometry and, in particular, violations of Lorentz invariance. In the so-called multifractional theory with q-derivatives, we show that the deformation of dispersion relations is much stronger than in generic quantum-gravity approaches (including loop quantum gravity) and, contrary to the latter, present observations on GWs can place very strong bounds on the characteristic scales at which spacetime deviates from standard Minkowski. The energy at which multifractal effects should become apparent is E{sub *} > 10{sup 14} GeV (thus improving previous bounds by 12 orders of magnitude) when the exponents in the measure are fixed to their central value 1 / 2. We also estimate, for the first time, the effect of logarithmic oscillations in the measure (corresponding to a discrete spacetime structure) and find that they do not change much the bounds obtained in their absence, unless the amplitude of the oscillations is fine tuned. This feature, unavailable in known quantum-gravity scenarios, may help the theory to avoid being ruled out by gamma-ray burst (GRB) observations, for which E{sub *} > 10{sup 17} GeV or greater. (orig.)

Differences between Roma and non-Roma in how social support from family and friends helps to overcome health care accessibility problems.

Science.gov (United States)

Bobakova, Daniela; Dankulincova Veselska, Zuzana; Babinska, Ingrid; Klein, Daniel; Madarasova Geckova, Andrea; Cislakova, Lydia

2015-04-14

Roma are the most deprived ethnic minority in Slovakia, suffering from discrimination, poverty and social exclusion. Problematic access to good quality health care as result of institutional and interpersonal discrimination affects their health; therefore, factors which affect health care accessibility of Roma are of high importance for public health and policy makers. The aim of this study was to explore the association between health care accessibility problems and ethnicity and how different levels of social support from family and friends affect this association. We used data from the cross-sectional HepaMeta study conducted in 2011 in Slovakia. The final sample comprised 452 Roma (mean age = 34.7; 35.2% men) and 403 (mean age = 33.5; 45.9% men) non-Roma respondents. Roma in comparison with non-Roma have a more than 3-times higher chance of reporting health care accessibility problems. Social support from family and friends significantly decreases the likelihood of reporting health care accessibility problems in both Roma and non-Roma, while the family seems to be the more important factor. The worse access to health care of Roma living in so-called settlements seems to be partially mediated by social support. Interventions should focus on Roma health mediators and community workers who can identify influential individuals who are able to change a community's fear and distrust and persuade and teach Roma to seek and appropriately use health care services.

Multi-probleemgezinnen met een Roma-achtergrond: waarom verloopt hun integratie moeizaam?

Directory of Open Access Journals (Sweden)

Vina Wijkhuijs

2014-03-01

Full Text Available Roma multi-problem families in the Netherlands: what hinders their integration?The European Commission has entrusted the EU Member States with the preparation of a national Roma integration strategy in order to address more effectively the challenges of the inclusion of Europe’s largest ethnic minority. This article offers insight into the complex situation of Roma communities in the Netherlands on the basis of the following question: What is known about the problems that occur in families with a Roma background and what recommendations can be made to promote their integration? This article is based on 33 interviews with professionals from different welfare organizations and social services. What follows is that intervention is necessary in certain families, but to accomplish this, problems relating to the attitudes of these families and inconsistencies in care and (law enforcement policies must be overcome. Given the highly complex nature of these issues, the integration of Roma multi problem families requires a long-term and, most of all, consistent approach.Multi-probleemgezinnen met een Roma-achtergrond: waarom verloopt hun integratie moeizaam?De Europese Commissie heeft de EU-lidstaten opgedragen een aanpak te ontwikkelen voor de integratie van Roma, zijnde de grootste etnische minderheidsgroep in Europa. Deze bijdrage belicht de situatie in Nederland aan de hand van de volgende vraag: Wat is onder professionals bekend over de problemen die zich bij gezinnen met een Roma-achtergrond voordoen en welke aanbevelingen kunnen worden gedaan om hun integratie te bevorderen? Wat volgt is dat interventie in bepaalde gezinnen noodzakelijk is, maar dat de aanpak stuit op de houding en leefwijze van deze gezinnen en op inconsistenties in de hulpverlening en handhaving. Wat nodig is, is aandacht voor het bijzondere van de problematiek zonder deze te verbijzonderen, en versterking van de ketenregie.

Challenges in sexual and reproductive health of Roma people who live in settlements in Serbia.

Science.gov (United States)

Sedlecky, Katarina; Rašević, Mirjana

2015-04-01

To investigate the differences in sexual and reproductive health (SRH) between Roma women of reproductive age who live in settlements and the general population of women of the same age in Serbia who do not live in settlements. The Multiple Indicator Cluster Survey 4 (MICS4) was administered to Roma and Serbian women and the results were compared between the two groups. In order to get a qualitative perspective, a specifically designed, short open-ended questionnaire about Roma women was given to Roma Health Mediators (RHMs). Roma women have a higher total fertility rate and adolescent birth rate, and early marriage is much more common among them. Differences are less clear regarding antenatal care and assistance during delivery from skilled personnel. Roma women more frequently rely on traditional contraception, and are less likely to use modern contraceptives than the general female population. Problems in the socio-economic sphere, poor school enrolment and maintenance of traditional patterns in Roma people living in settlements contribute to the disparities observed. Although data on the SRH of the general population of women in Serbia are far from being satisfactory, those for women who live in Roma settlements are much worse. Political actions aimed at the empowerment of Roma women in the spheres of education, employment and health promotion have been implemented with the hope that they might improve the SRH of this vulnerable population group.

Delinquent and Aggressive Behavior and Social Desirability Among Roma and Non-Roma Adolescents in Slovakia : A Cross-Sectional Study

NARCIS (Netherlands)

Kolarcik, Peter; Geckova, Andrea Madarasova; Reijneveld, Sijmen A.; van Dijk, Jitse P.

Rates of aggression and delinquency are assumed to be higher among Roma and other minorities, but sound evidence of this is lacking. Our aim was to assess delinquent and aggressive behavior among Roma and non-Roma adolescents and the effects on ethnic differences of parental education and social

Predictors of health-endangering behaviour among Roma and non-Roma adolescents in Slovakia by gender

NARCIS (Netherlands)

Kolarcik, P.; Geckova, A. M.; Orosova, O.; van Dijk, J. P.; Reijneveld, S. A.

2010-01-01

Background Roma people are commonly described as having an unhealthy lifestyled-for example, an unhealthy diet, intensive smoking, frequent alcohol consumption and a lack of physical activity. However, data about such health-endangering behaviours among Roma adolescents are scarce and of poor

Reconstructing Roma history from genome-wide data.

Directory of Open Access Journals (Sweden)

Priya Moorjani

Full Text Available The Roma people, living throughout Europe and West Asia, are a diverse population linked by the Romani language and culture. Previous linguistic and genetic studies have suggested that the Roma migrated into Europe from South Asia about 1,000-1,500 years ago. Genetic inferences about Roma history have mostly focused on the Y chromosome and mitochondrial DNA. To explore what additional information can be learned from genome-wide data, we analyzed data from six Roma groups that we genotyped at hundreds of thousands of single nucleotide polymorphisms (SNPs. We estimate that the Roma harbor about 80% West Eurasian ancestry-derived from a combination of European and South Asian sources-and that the date of admixture of South Asian and European ancestry was about 850 years before present. We provide evidence for Eastern Europe being a major source of European ancestry, and North-west India being a major source of the South Asian ancestry in the Roma. By computing allele sharing as a measure of linkage disequilibrium, we estimate that the migration of Roma out of the Indian subcontinent was accompanied by a severe founder event, which appears to have been followed by a major demographic expansion after the arrival in Europe.

Multifractal features of EUA and CER futures markets by using multifractal detrended fluctuation analysis based on empirical model decomposition

International Nuclear Information System (INIS)

Cao, Guangxi; Xu, Wei

2016-01-01

Basing on daily price data of carbon emission rights in futures markets of Certified Emission Reduction (CER) and European Union Allowances (EUA), we analyze the multiscale characteristics of the markets by using empirical mode decomposition (EMD) and multifractal detrended fluctuation analysis (MFDFA) based on EMD. The complexity of the daily returns of CER and EUA futures markets changes with multiple time scales and multilayered features. The two markets also exhibit clear multifractal characteristics and long-range correlation. We employ shuffle and surrogate approaches to analyze the origins of multifractality. The long-range correlations and fat-tail distributions significantly contribute to multifractality. Furthermore, we analyze the influence of high returns on multifractality by using threshold method. The multifractality of the two futures markets is related to the presence of high values of returns in the price series.

MULTIFRACTAL ANALYSIS OFTHE DYNAMICS OF TURKISHEXCHANGE RATE

Directory of Open Access Journals (Sweden)

Ezgi Gülbaş

2013-01-01

Full Text Available We perform a comparative study of applicability of the Multifractal DetrendedFluctuation Analysis (MFDFA and the Wavelet Transform Modulus Maxima(WTMM method in properly detecting ofmono- and multifractal character ofdata. After summarizing the theory behind both methods, we apply both methodson USD/TRY currency. The results show thatour data has multifractal nature butnot at high level and multifractality ispoorer if WTMM method is used. We alsoinvestigated whether other Eastern European country currencies, such as RussianRubble and Hungarian Forint have multifractal characters by using MFDFAmethod. Therefore, forecasters have often encountered in trying to predict theseexchange rates with models that do notincorporate any notion of inhomogeneitywill have little predictive power.

Multifractional theories: an unconventional review

Energy Technology Data Exchange (ETDEWEB)

Calcagni, Gianluca [Instituto de Estructura de la Materia, CSIC,Serrano 121, 28006 Madrid (Spain)

2017-03-27

We answer to 72 frequently asked questions about theories of multifractional spacetimes. Apart from reviewing and reorganizing what we already know about such theories, we discuss the physical meaning and consequences of the very recent flow-equation theorem on dimensional flow in quantum gravity, in particular its enormous impact on the multifractional paradigm. We will also get new theoretical results about the construction of multifractional derivatives and the symmetries in the yet-unexplored theory T{sub γ}, the resolution of ambiguities in the calculation of the spectral dimension, the relation between the theory T{sub q} with q-derivatives and the theory T{sub γ} with fractional derivatives, the interpretation of complex dimensions in quantum gravity, the frame choice at the quantum level, the physical interpretation of the propagator in T{sub γ} as an infinite superposition of quasiparticle modes, the relation between multifractional theories and quantum gravity, and the issue of renormalization, arguing that power-counting arguments do not capture the exotic properties of extreme UV regimes of multifractional geometry, where T{sub γ} may indeed be renormalizable. A careful discussion of experimental bounds and new constraints are also presented.

Health behaviors, nutritional status, and anthropometric parameters of Roma and non-Roma mothers and their infants in the Czech Republic.

Science.gov (United States)

Rambousková, Jolana; Dlouhý, Pavel; Krízová, Eva; Procházka, Bohumír; Hrncírová, Dana; Andel, Michal

2009-01-01

To compare maternal health behaviors, maternal nutritional status, and infant size at birth of Romas and non-Romas in the Czech Republic. Maternal interviews and food frequency questionnaire, maternal blood samples, physical measurements of mothers and infants. Hospital, maternal/child care center; 2-4 days postpartum. 76 Roma mothers and 151 mothers from the majority population. Infant length/weight; maternal height/weight; weight gain during pregnancy; duration of pregnancy; maternal smoking habits; dietary intake; use of food supplements during pregnancy; and maternal blood levels of folate, beta-carotene, retinol, and alpha-tocopherol. Comparison of ethnic groups by 2-sample Wilcoxon test, chi-square, Fischer's exact test, relative risk, and analysis of variance (ANOVA). Pregnancy duration was about 1 week shorter in Roma women (P nutritional status of Roma mothers is worse than that of mothers from the majority Czech population. The dietary and smoking habits of pregnant Roma women should be of special concern to family doctors, obstetricians, nutrition educators, and social workers.

Rethinking the Role of Pedagogical Assistants: Establishing Cooperation between Roma Families and Schools in Serbia

Directory of Open Access Journals (Sweden)

Jelena Starčević

2016-12-01

Full Text Available The aim of the present paper is to examine the risks and challenges related to the cooperation of pedagogical assistants (PAs with Roma parents/ families and their work with Roma pupils, as well as to offer further insight into ways to overcome these risks and challenges. Roma pupils and parents/ families face numerous difficulties in education, which are reflected in prejudice, stereotypes and discrimination. The education policy measure of introducing PAs, formerly known as Roma teaching assistants, to the Serbian education system aimed to contribute to the learning and social participation of Roma pupils and to establish cooperation between school staff and Roma parents. The further segregation of Roma pupils and the reduced engagement of teachers in supporting Roma pupils and fostering communication with Roma parents are seen as possible risks related to the engagement of PAs. In order to minimise the risks, we propose a framework for defining and understanding the roles of teachers and PAs from an intercultural perspective. Relying on two concepts – intercultural sensitivity (IS and intercultural competence (IC – we elaborate the necessity of perceiving cultural differences in accordance with an ethnorelative world view, on the part of both teachers and PAs. In addition, we outline the cognitive, affective and behavioural aspects of IC that we believe teachers and PAs should possess. Further recommendations regarding the engagement of PAs and the minimisation of risks and challenges are proposed.

Roma Women in Athenian Firms: Do They Face Wage Bias?

OpenAIRE

Drydakis, Nick

2011-01-01

In the current study, we analyze the effect of having a Roma background on women's wages. By utilizing the Athens Area Study random sample (2007-08) drawn from 16 multiethnic municipalities in which Roma live, we estimate that 66.1% of the wage differential between Roma and non-Roma female workers cannot be explained by differences in observed characteristics. Prejudices against Roma women are discussed and appear to explain the wage gap found here. The occupational segregation of the Roma in...

Roma Interrotta. The Urbs that is not a Capital

Directory of Open Access Journals (Sweden)

Maarten Delbeke

2011-12-01

Full Text Available Roma Interrotta. L’Urbe non è una capitale   Nel 1978 fu presentato a Roma il progetto Roma Interrotta, comprendente progettazioni urbane elaborate da dodici architetti di fama internazionale ispiratisi alla Nuova Pianta di Roma di Giambattista Nolli (1748. Il titolo e la struttura del progetto ne sottolineano il carattere critico: lo sviluppo di Roma sarebbe stato interrotto verso la metà del XVIII secolo e in particolare dopo il 1870 la città avrebbe subito una drammatica trasformazione, per cui le tracce della sua evoluzione storica non sarebbero quasi più visibili. I progetti avanzati vogliono essere un tentativo di riallacciarsi nuovamente a tale evoluzione. In questo contributo si esplorano le idee su Roma capitale avanzate da architetti e storici dell’architettura negli anni Settanta del secolo scorso, al fine di comprendere le ragioni del loro radicale rifiuto della Terza Roma e perché tale presa di posizione fosse proprio in quel momento attuale e importante. La Roma barocca immaginata da Nolli funge nell’ambito dell’architettura come un’immagine ideale della città, tuttavia anche essa è completamente spogliata da qualunque significato culturale e politico. Le proposte di Roma Interrotta dunque non sono soltanto esemplari del dibattito sviluppatosi nel mondo dell’architettura nel periodo considerato, ma ne rivelano anche i limiti intrinseci e le lacune.

Multifractal analysis of complex networks

International Nuclear Information System (INIS)

Wang Dan-Ling; Yu Zu-Guo; Anh V

2012-01-01

Complex networks have recently attracted much attention in diverse areas of science and technology. Many networks such as the WWW and biological networks are known to display spatial heterogeneity which can be characterized by their fractal dimensions. Multifractal analysis is a useful way to systematically describe the spatial heterogeneity of both theoretical and experimental fractal patterns. In this paper, we introduce a new box-covering algorithm for multifractal analysis of complex networks. This algorithm is used to calculate the generalized fractal dimensions D q of some theoretical networks, namely scale-free networks, small world networks, and random networks, and one kind of real network, namely protein—protein interaction networks of different species. Our numerical results indicate the existence of multifractality in scale-free networks and protein—protein interaction networks, while the multifractal behavior is not clear-cut for small world networks and random networks. The possible variation of D q due to changes in the parameters of the theoretical network models is also discussed. (general)

A multifractal analysis of Asian foreign exchange markets

Science.gov (United States)

Oh, G.; Eom, C.; Havlin, S.; Jung, W.-S.; Wang, F.; Stanley, H. E.; Kim, S.

2012-06-01

We analyze the multifractal spectra of daily foreign exchange rates for Japan, Hong-Kong, Korea, and Thailand with respect to the United States in the period from 1991 until 2005. We find that the return time series show multifractal spectrum features for all four cases. To observe the effect of the Asian currency crisis, we also estimate the multifractal spectra of limited series before and after the crisis. We find that the Korean and Thai foreign exchange markets experienced a significant increase in multifractality compared to Hong-Kong and Japan. We also show that the multifractality is stronger related to the presence of high values of returns in the series.

Two-dimensional multifractal cross-correlation analysis

International Nuclear Information System (INIS)

Xi, Caiping; Zhang, Shuning; Xiong, Gang; Zhao, Huichang; Yang, Yonghong

2017-01-01

Highlights: • We study the mathematical models of 2D-MFXPF, 2D-MFXDFA and 2D-MFXDMA. • Present the definition of the two-dimensional N 2 -partitioned multiplicative cascading process. • Do the comparative analysis of 2D-MC by 2D-MFXPF, 2D-MFXDFA and 2D-MFXDMA. • Provide a reference on the choice and parameter settings of these methods in practice. - Abstract: There are a number of situations in which several signals are simultaneously recorded in complex systems, which exhibit long-term power-law cross-correlations. This paper presents two-dimensional multifractal cross-correlation analysis based on the partition function (2D-MFXPF), two-dimensional multifractal cross-correlation analysis based on the detrended fluctuation analysis (2D-MFXDFA) and two-dimensional multifractal cross-correlation analysis based on the detrended moving average analysis (2D-MFXDMA). We apply these methods to pairs of two-dimensional multiplicative cascades (2D-MC) to do a comparative study. Then, we apply the two-dimensional multifractal cross-correlation analysis based on the detrended fluctuation analysis (2D-MFXDFA) to real images and unveil intriguing multifractality in the cross correlations of the material structures. At last, we give the main conclusions and provide a valuable reference on how to choose the multifractal algorithms in the potential applications in the field of SAR image classification and detection.

Searching for a multifractal signature of the lake algal proliferation, a multifractal correlation

Science.gov (United States)

Mezemate, Yacine; Tchiguirinskaia, Ioulia; Bonhomme, Celine; Schertzer, Daniel; Lemaire, Bruno Jacques; Vinçon leite, Brigitte; Lovejoy, Shaun

2013-04-01

Green algae proliferations affect water bodies such as the Lake Bourget (France). They are an environmental issue as well as a mater of public health. In the framework of the PROLIPHYC project a system based on temperature and chlorophyll measurements coupled to a lake model was implemented to predict sudden algal blooms. This classical approach relies on the analysis of large scale trends of the measured fields and does not take into account small scale fluctuations. A more innovative approach has been developed by the R2DS PLUMMME project to investigate the correlation between environmental fields across the full range of space-time scales, down to the smallest scale of observations. The first results of the project demonstrate that multi-scaling behaviour of environmental fields, such as temperature and chlorophyll, becomes evident only after the removal of the large-scale data trends that otherwise induce biases to the multifractal parameter estimates. First, a spectral analysis of temperature and chlorophyll data is performed on sub-samples of the time series to investigate the scaling behaviour. The multifractal analysis (Trace Moment, Double Trace Moment) directly applied on each sub-sample shows unsatisfying results on some sub-samples, in particular on those having a strong gradient compared with the amplitude of the fluctuations. Hence, non-stationary and seasonal effects should be first removed from the time series. To put on evidence a good scaling of the analysed data, we choose the Hilbert-Huang transform to de-trend the data. This method has been widely used for different fields (see F.G.Schmitt et al, 2009 for review). After having applied this method, the K(q) function shows that the investigated fields are indeed multifractal and the determination of their multifractal parameters becomes robust. Then, we proceed to a multifractal correlation analysis between the fields. In conclusion, we discuss the prediction of algal blooms based on multifractal

Ethnic and social distance towards Roma population

Directory of Open Access Journals (Sweden)

Miladinović Slobodan

2008-01-01

Full Text Available The Roma people are one of social marginalised ethnic groups which can easily be classified as underclass or ethno-class. In this work are presented the results of survey data analysis of ethnic and social distance towards the Roma population (2007. It concludes that the Roma people are one of ethnic groups with the highest social and ethnic distances in all observed social relations. The conclusion is that their generations poverty and still of life which the poverty produces are main causes of the high distance. The society has very important task to overcome situation which keep their social situation. In this paper are showed some of possible solutions of solving global Romas social situation and their integration in the rest of society. .

Ethnic differences in smoking behaviour: The situation of Roma in Eastern Europe

Directory of Open Access Journals (Sweden)

Laetitia Duval

2016-12-01

Full Text Available Aim: To investigate ethnic differences in smoking between Roma and non-Roma and their determinants, including how discrimination faced by Roma may influence smoking decisions. Methods: We analysed data from the Roma Regional Survey 2011 implemented in twelve countries of Central and South-East Europe with random samples of approximately 750 households in Roma settlements and 350 households in nearby non-Roma communities in each country. The overall sample comprises 11,373 individuals (8,234 Roma with a proportion of women of 57% and an average age of 36 years. Statistical methods include marginal effects from Probit and zero-truncated negative binomial estimates to explain cigarette consumption. Results: We found that Roma have a higher probability of smoking and are heavier smokers compared to otherwise comparable non-Roma. These differences in smoking behaviour cannot purely be explained by the lower socio-economic situation of Roma since the ethnic gap remains substantial once individual characteristics are controlled for. The probability of smoking is positively correlated with the degree of ethnic discrimination experienced by Roma, especially when it is related to private or public health services. Conclusions: By providing evidence on smoking behaviour between Roma and non-Roma in a large number of countries, our findings support the need to understand smoking behaviour of Roma from a comparative perspective, and may ultimately contribute to more effective anti-smoking messages for Roma. However, if the health disadvantage faced by Roma is to be addressed adequately, this group must be involved more effectively in the policy and public health process.

Multifractal analysis of managed and independent float exchange rates

Science.gov (United States)

Stošić, Darko; Stošić, Dusan; Stošić, Tatijana; Stanley, H. Eugene

2015-06-01

We investigate multifractal properties of daily price changes in currency rates using the multifractal detrended fluctuation analysis (MF-DFA). We analyze managed and independent floating currency rates in eight countries, and determine the changes in multifractal spectrum when transitioning between the two regimes. We find that after the transition from managed to independent float regime the changes in multifractal spectrum (position of maximum and width) indicate an increase in market efficiency. The observed changes are more pronounced for developed countries that have a well established trading market. After shuffling the series, we find that the multifractality is due to both probability density function and long term correlations for managed float regime, while for independent float regime multifractality is in most cases caused by broad probability density function.

NEW SUNS IN THE COSMOS. III. MULTIFRACTAL SIGNATURE ANALYSIS

Energy Technology Data Exchange (ETDEWEB)

Freitas, D. B. de; Nepomuceno, M. M. F.; Junior, P. R. V. de Moraes; Chagas, M. L. Das; Bravo, J. P.; Costa, A. D.; Martins, B. L. Canto; Medeiros, J. R. De [Departamento de Física, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, RN (Brazil); Lopes, C. E. F. [SUPA Wide-Field Astronomy Unit, Institute for Astronomy, School of Physics and Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Leão, I. C. [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching (Germany)

2016-11-01

In the present paper, we investigate the multifractality signatures in hourly time series extracted from the CoRoT spacecraft database. Our analysis is intended to highlight the possibility that astrophysical time series can be members of a particular class of complex and dynamic processes, which require several photometric variability diagnostics to characterize their structural and topological properties. To achieve this goal, we search for contributions due to a nonlinear temporal correlation and effects caused by heavier tails than the Gaussian distribution, using a detrending moving average algorithm for one-dimensional multifractal signals (MFDMA). We observe that the correlation structure is the main source of multifractality, while heavy-tailed distribution plays a minor role in generating the multifractal effects. Our work also reveals that the rotation period of stars is inherently scaled by the degree of multifractality. As a result, analyzing the multifractal degree of the referred series, we uncover an evolution of multifractality from shorter to larger periods.

Pre-Primary Education of Roma Children in Serbia: Barriers and Possibilities

Directory of Open Access Journals (Sweden)

Sunčica Macura-Milovanović

2013-01-01

Full Text Available In Serbia, as in the other countries of the Western Balkans and South-Eastern Europe, the most disadvantaged communities belong to the Roma minority. The present paper demonstrates the conditions of Roma preschool children in Serbia: primarily their early education, but also habitation and health in Roma settlements. The data highlight the under-representation of Roma children in pre-primary education, although their growing up in extremely deprived settlements would suggest a need for their earliest possible inclusion in pre-primary services. The paper analyses the following barriers to the access of Roma children to the system of pre-primary education: the poverty of Roma families; discrimination and prejudice towards Roma; the lack of intercultural provision; insufficient inter-sectorial cooperation; the underdeveloped network of preschool institutions; and the absence of kindergartens in Roma settlements. In addition, possible ways to increase the coverage of Roma children in pre-primary education are discussed. As a transitory solution, the paper proposes comprehensivecommunity-based programmes that could contribute to the education, care, health and overall development of young Roma children before their inclusion in desegregated programmes in preschool institutions.

Health impact assessment of Roma housing policies in Central and Eastern Europe: A comparative analysis

International Nuclear Information System (INIS)

Molnár, Ágnes; Ádám, Balázs; Antova, Temenujka; Bosak, Lubos; Dimitrov, Plamen; Mileva, Hristina; Pekarcikova, Jarmila; Zurlyte, Ingrida; Gulis, Gabriel; Ádány, Róza; Kósa, Karolina

2012-01-01

Marginalised Roma communities in European countries live in substandard housing conditions the improvement of which has been one of the major issues of the Decade of Roma Inclusion, the ongoing intergovernmental European Roma programme. The paper presents EU-funded health impact assessments of national Roma housing policies and programmes in 3 Central and Eastern European countries in light of the evaluation of a completed local project in a fourth CEE country so as to compare predicted effects to observed ones. Housing was predicted to have beneficial health effects by improving indoor and outdoor conditions, access to services, and socioeconomic conditions. Negative impacts were predicted only in terms of maintenance expenses and housing tenure. However, observed impacts of the completed local project did not fully support predictions especially in terms of social networks, satisfaction with housing and neighbourhood, and inhabitant safety. In order to improve the predictive value of HIA, more evidence should be produced by the careful evaluation of locally implemented housing projects. In addition, current evidence is in favour of planning Roma housing projects at the local rather than at the national level in alignment with the principle of subsidiarity. - Highlights: ► Predictive validity of HIA of national Roma housing policies – in light of current evidence – is low. ► Implemented housing projects should be comprehensively evaluated to improve reliability of HIA. ► Roma housing projects should be planned at the local rather than at the national level. ► HIA should be used to plan Roma housing projects at the local level.

The Roma in Croatia: From Migration to Intercultural Relations

Directory of Open Access Journals (Sweden)

Neven Hrvatić

2004-12-01

Full Text Available From their first arrival in Croatia (in Dubrovnik in 1362, due to their transnational identity, the Roma have formed a historical ethnic community. A specific tribal system and economic backwardness determined their dispersion, specialisation, the partial loss of their ethnic identity and their marginal position. Based on empirical surveys carried out among secondary school students in Croatia, the scientific research projects: “Genealogy and the Transfer of Intercultural Models” and “The School Curriculum and the Traits of Croatian National Culture” (1991–2001, have revealed the existence of stereotypes in regard to the Roma, a low level of acceptance of elements of Roma culture (language, art, history, customs, as well as great social distance towards the Roma (through a modified Bogardus scale, which altogether indicates a need for intercultural education and schooling for all school pupils in Croatia. An improvement in their socio-economic situation and integration into all segments of society is crucial to the Roma national minority in Croatia, but there is likewise a need to preserve Roma culture, traditions and lifestyle, so that the Roma could become and/or remain a recognisable part of the multicultural milieu.

Finite-size effect and the components of multifractality in financial volatility

International Nuclear Information System (INIS)

Zhou Weixing

2012-01-01

Highlights: ► The apparent multifractality can be decomposed quantitatively. ► There is a marked finite-size effect in the detection of multifractality. ► The effective multifractality can be further decomposed into two components. ► A time series exhibits effective multifractality only if it possesses nonlinearity. ► The daily DJIA volatility is analyzed as an example. - Abstract: Many financial variables are found to exhibit multifractal nature, which is usually attributed to the influence of temporal correlations and fat-tailedness in the probability distribution (PDF). Based on the partition function approach of multifractal analysis, we show that there is a marked finite-size effect in the detection of multifractality, and the effective multifractality is the apparent multifractality after removing the finite-size effect. We find that the effective multifractality can be further decomposed into two components, the PDF component and the nonlinearity component. Referring to the normal distribution, we can determine the PDF component by comparing the effective multifractality of the original time series and the surrogate data that have a normal distribution and keep the same linear and nonlinear correlations as the original data. We demonstrate our method by taking the daily volatility data of Dow Jones Industrial Average from 26 May 1896 to 27 April 2007 as an example. Extensive numerical experiments show that a time series exhibits effective multifractality only if it possesses nonlinearity and the PDF has an impact on the effective multifractality only when the time series possesses nonlinearity. Our method can also be applied to judge the presence of multifractality and determine its components of multifractal time series in other complex systems.

Roma Minority in Romania and its Media Representation

Directory of Open Access Journals (Sweden)

Gabriela Creţu

2014-11-01

Full Text Available The aim of this paper is to put into light main aspects of the relationship between the image of Roma as perceived by the majority of population and its representation in the Romanian press from 1990 until 2006. The representation of Roma is considered a cause and, in the same time, a consequence of the identity problem of this population as an ethnic group, on one side, and of its social status, on the other side. The situation of Roma in the Romanian society, the modalities of Roma portrayal in press and the factors that influence its representation are addressed in the paper.

Rank distributions: A panoramic macroscopic outlook

Science.gov (United States)

Eliazar, Iddo I.; Cohen, Morrel H.

2014-01-01

This paper presents a panoramic macroscopic outlook of rank distributions. We establish a general framework for the analysis of rank distributions, which classifies them into five macroscopic "socioeconomic" states: monarchy, oligarchy-feudalism, criticality, socialism-capitalism, and communism. Oligarchy-feudalism is shown to be characterized by discrete macroscopic rank distributions, and socialism-capitalism is shown to be characterized by continuous macroscopic size distributions. Criticality is a transition state between oligarchy-feudalism and socialism-capitalism, which can manifest allometric scaling with multifractal spectra. Monarchy and communism are extreme forms of oligarchy-feudalism and socialism-capitalism, respectively, in which the intrinsic randomness vanishes. The general framework is applied to three different models of rank distributions—top-down, bottom-up, and global—and unveils each model's macroscopic universality and versatility. The global model yields a macroscopic classification of the generalized Zipf law, an omnipresent form of rank distributions observed across the sciences. An amalgamation of the three models establishes a universal rank-distribution explanation for the macroscopic emergence of a prevalent class of continuous size distributions, ones governed by unimodal densities with both Pareto and inverse-Pareto power-law tails.

Multifractal characteristics of multiparticle production in heavy-ion collisions at SPS energies

Science.gov (United States)

Khan, Shaista; Ahmad, Shakeel

Entropy, dimensions and other multifractal characteristics of multiplicity distributions of relativistic charged hadrons produced in ion-ion collisions at SPS energies are investigated. The analysis of the experimental data is carried out in terms of phase space bin-size dependence of multiplicity distributions following the Takagi’s approach. Yet another method is also followed to study the multifractality which, is not related to the bin-width and (or) the detector resolution, rather involves multiplicity distribution of charged particles in full phase space in terms of information entropy and its generalization, Rényi’s order-q information entropy. The findings reveal the presence of multifractal structure — a remarkable property of the fluctuations. Nearly constant values of multifractal specific heat “c” estimated by the two different methods of analysis followed indicate that the parameter “c” may be used as a universal characteristic of the particle production in high energy collisions. The results obtained from the analysis of the experimental data agree well with the predictions of Monte Carlo model AMPT.

Investigation of multifractality in the Brazilian stock market

Science.gov (United States)

Maganini, Natália Diniz; Da Silva Filho, Antônio Carlos; Lima, Fabiano Guasti

2018-05-01

Many studies point to a possible new stylized fact for financial time series: the multifractality. Several authors have already detected this characteristic in multiple time series in several countries. With that in mind and based on Multifractal Detrended Fluctuation Analysis (MFDFA) method, this paper analyzes the multifractality in the Brazilian market. This analysis is performed with daily data from IBOVESPA index (Brazilian stock exchange's main index) and other four highly marketable stocks in the Brazilian market (VALE5, ITUB4, BBDC4 and CIEL3), which represent more than 25% of the index composition, making up 1961 observations for each asset in the period from June 26 2009 to May 31 2017. We found that the studied stock prices and Brazilian index are multifractal, but that the multifractality degree is not the same for all the assets. The use of shuffled and surrogated series indicates that for the period and the actions considered the long-range correlations do not strongly influence the multifractality, but the distribution (fat tails) exerts a possible influence on IBOVESPA and CIEL3.

Determination of key parameters of vector multifractal vector fields

Science.gov (United States)

Schertzer, D. J. M.; Tchiguirinskaia, I.

2017-12-01

For too long time, multifractal analyses and simulations have been restricted to scalar-valued fields (Schertzer and Tchiguirinskaia, 2017a,b). For instance, the wind velocity multifractality has been mostly analysed in terms of scalar structure functions and with the scalar energy flux. This restriction has had the unfortunate consequences that multifractals were applicable to their full extent in geophysics, whereas it has inspired them. Indeed a key question in geophysics is the complexity of the interactions between various fields or they components. Nevertheless, sophisticated methods have been developed to determine the key parameters of scalar valued fields. In this communication, we first present the vector extensions of the universal multifractal analysis techniques to multifractals whose generator belong to a Levy-Clifford algebra (Schertzer and Tchiguirinskaia, 2015). We point out further extensions noting the increased complexity. For instance, the (scalar) index of multifractality becomes a matrice. Schertzer, D. and Tchiguirinskaia, I. (2015) `Multifractal vector fields and stochastic Clifford algebra', Chaos: An Interdisciplinary Journal of Nonlinear Science, 25(12), p. 123127. doi: 10.1063/1.4937364. Schertzer, D. and Tchiguirinskaia, I. (2017) `An Introduction to Multifractals and Scale Symmetry Groups', in Ghanbarian, B. and Hunt, A. (eds) Fractals: Concepts and Applications in Geosciences. CRC Press, p. (in press). Schertzer, D. and Tchiguirinskaia, I. (2017b) `Pandora Box of Multifractals: Barely Open ?', in Tsonis, A. A. (ed.) 30 Years of Nonlinear Dynamics in Geophysics. Berlin: Springer, p. (in press).

Social distance and stereotypes of Roma at the primary school age

Directory of Open Access Journals (Sweden)

Franceško Mirjana

2006-01-01

Full Text Available The sample of the research presented in this paper consisted of 575 children age 10 and 11 from four of Novi Sad`s primary school. 58 of them were Roma and the rest were Serbs, Hungarians, Croats, etc. The paper deals with the social distance toward the six ethnic groups (Roma, Serbs, Croats Hungarians, Slovaks and Ruthenians, as well as stereotypes of Roma both in Roma and non-Roma children. Sample has also been divided in two by the criteria of Roma children attending the same classes as the children in the sample or not. The results show that social distance toward the Roma is higher than any other social distance in this sample. Also, we were not able to find any significant differences in this social distance between children who attend the school with the Roma children and those who do not. As could be expected, the auto stereotypes were more positive than the hetero stereotypes.

Life Satisfaction and Happiness Among the Roma in Central and Southeastern Europe

NARCIS (Netherlands)

Kamberi, Ermira; Martinovic, Borja; Verkuijten, Maykel

2015-01-01

This study examines general life satisfaction and happiness as two indicators of subjective well-being among Roma and non-Roma populations in Central and Southeastern Europe. Using a sample of 11,997 participants (Roma N = 8,399, non-Roma N = 3,598) from the Regional Roma Survey in 2011 we test a

Diffusion and scattering in multifractal clouds

Energy Technology Data Exchange (ETDEWEB)

Lovejoy, S. [McGill Univ., Montreal, Quebec (Canada); Schertzer, D. [Universite Pierre et Marie Curie, Paris (France); Waston, B. [St. Lawrence Univ., Canton, NY (United States)] [and others

1996-04-01

This paper describes investigations of radiative properties of multifractal clouds using two different approaches. In the first, diffusion is considered by examining the scaling properties of one dimensional random walks on media with multifractal diffusivities. The second approach considers the scattering statistics associated with radiative transport.

Multifractal Conceptualisation of Hydro-Meteorological Extremes

Science.gov (United States)

Tchiguirinskaia, I.; Schertzer, D.; Lovejoy, S.

2009-04-01

Hydrology and more generally sciences involved in water resources management, technological or operational developments face a fundamental difficulty: the extreme variability of hydro-meteorological fields. It clearly appears today that this variability is a function of the observation scale and yield hydro-meteorological hazards. Throughout the world, the development of multifractal theory offers new techniques for handling such non-classical variability over wide ranges of time and space scales. The resulting stochastic simulations with a very limited number of parameters well reproduce the long range dependencies and the clustering of rainfall extremes often yielding fat tailed (i.e., an algebraic type) probability distributions. The goal of this work was to investigate the ability of using very short or incomplete data records for reliable statistical predictions of the extremes. In particular we discuss how to evaluate the uncertainty in the empirical or semi-analytical multifractal outcomes. We consider three main aspects of the evaluation, such as the scaling adequacy, the multifractal parameter estimation error and the quantile estimation error. We first use the multiplicative cascade model to generate long series of multifractal data. The simulated samples had to cover the range of the universal multifractal parameters widely available in the scientific literature for the rainfall and river discharges. Using these long multifractal series and their sub-samples, we defined a metric for parameter estimation error. Then using the sets of estimated parameters, we obtained the quantile values for a range of excedance probabilities from 5% to 0.01%. Plotting the error bars on a quantile plot enable an approximation of confidence intervals that would be particularly important for the predictions of multifractal extremes. We finally illustrate the efficiency of such concept on its application to a large database (more than 16000 selected stations over USA and

A Community-Based Study to Estimate the Seroprevalence of Trichinellosis and Echinococcosis in the Roma and Non-Roma Population of Slovakia.

Science.gov (United States)

Antolová, Daniela; Halánová, Monika; Janičko, Martin; Jarčuška, Peter; Reiterová, Katarína; Jarošová, Júlia; Madarasová Gecková, Andrea; Pella, Daniel; Dražilová, Sylvia

2018-02-02

Trichinellosis and cystic and alveolar echinococcosis are serious parasitic diseases transmissible between animals and humans. Moreover, alveolar echinococcosis is considered one of the most dangerous of human helminthoses. Roma communities are particularly numerous in Central and Eastern Europe. They are often concentrated in economically undeveloped regions and live in segregated localities with unsatisfactory housing and sanitary conditions. The study aimed to find out the seroprevalence of Trichinella and Echinococcus infections in the Roma population of segregated settlements and to compare it with the seropositivity of the non-Roma population of eastern Slovakia. Out of 823 samples, three sera showed seropositivity to Trichinella in the ELISA (Enzyme-linked immunosorbent assay) test. Subsequent Western blot reaction (WB) confirmed seropositivity in two Roma women. ELISA seropositivity to E. multilocularis was recorded in six persons (0.73%), and five (0.61%) respondents were seropositive to E. granulosus , but WB confirmed the presence of antibodies to Echinococcus spp. in one Roma participant. Positive persons suffered from unspecific clinical symptoms; Trichinella -positive persons reported headache, cough, fatigue, and muscle pain. The Echinococcus -positive participant suffered from headache and back pain. The study showed that the worse living conditions of the Roma community did not significantly influence the occurrence of Trichinella and Echinococcus infections in this minority.

A Community-Based Study to Estimate the Seroprevalence of Trichinellosis and Echinococcosis in the Roma and Non-Roma Population of Slovakia

Directory of Open Access Journals (Sweden)

Daniela Antolová

2018-02-01

Full Text Available Trichinellosis and cystic and alveolar echinococcosis are serious parasitic diseases transmissible between animals and humans. Moreover, alveolar echinococcosis is considered one of the most dangerous of human helminthoses. Roma communities are particularly numerous in Central and Eastern Europe. They are often concentrated in economically undeveloped regions and live in segregated localities with unsatisfactory housing and sanitary conditions. The study aimed to find out the seroprevalence of Trichinella and Echinococcus infections in the Roma population of segregated settlements and to compare it with the seropositivity of the non-Roma population of eastern Slovakia. Out of 823 samples, three sera showed seropositivity to Trichinella in the ELISA (Enzyme-linked immunosorbent assay test. Subsequent Western blot reaction (WB confirmed seropositivity in two Roma women. ELISA seropositivity to E. multilocularis was recorded in six persons (0.73%, and five (0.61% respondents were seropositive to E. granulosus, but WB confirmed the presence of antibodies to Echinococcus spp. in one Roma participant. Positive persons suffered from unspecific clinical symptoms; Trichinella-positive persons reported headache, cough, fatigue, and muscle pain. The Echinococcus-positive participant suffered from headache and back pain. The study showed that the worse living conditions of the Roma community did not significantly influence the occurrence of Trichinella and Echinococcus infections in this minority.

Multifractal analysis of heartbeat dynamics during meditation training

Science.gov (United States)

Song, Renliang; Bian, Chunhua; Ma, Qianli D. Y.

2013-04-01

We investigate the multifractality of heartbeat dynamics during Chinese CHI meditation in healthy young adults. The results show that the range of multifractal singularity spectrum of heartbeat interval time series during meditation is significantly narrower than those in the pre-meditation state of the same subject, which indicates that during meditation the heartbeat becomes regular and the degree of multifractality decreases.

Price-volume multifractal analysis of the Moroccan stock market

Science.gov (United States)

El Alaoui, Marwane

2017-11-01

In this paper, we analyzed price-volume multifractal cross-correlations of Moroccan Stock Exchange. We chose the period from January 1st 2000 to January 20th 2017 to investigate the multifractal behavior of price change and volume change series. Then, we used multifractal detrended cross-correlations analysis method (MF-DCCA) and multifractal detrended fluctuation analysis (MF-DFA) to analyze the series. We computed bivariate generalized Hurst exponent, Rényi exponent and spectrum of singularity for each pair of indices to measure quantitatively cross-correlations. Furthermore, we used detrended cross-correlations coefficient (DCCA) and cross-correlation test (Q(m)) to analyze cross-correlation quantitatively and qualitatively. By analyzing results, we found existence of price-volume multifractal cross-correlations. The spectrum width has a strong multifractal cross-correlation. We remarked that volume change series is anti-persistent when we analyzed the generalized Hurst exponent for all moments q. The cross-correlation test showed the presence of a significant cross-correlation. However, DCCA coefficient had a small positive value, which means that the level of correlation is not very significant. Finally, we analyzed sources of multifractality and their degree of contribution in the series.

Health needs of the Roma population in the Czech and Slovak Republics.

Science.gov (United States)

Koupilová, I; Epstein, H; Holcík, J; Hajioff, S; McKee, M

2001-11-01

In the growing literature on the human rights of Roma people in Central Europe, their relatively poor health status is often mentioned. However, little concrete information exists about the contemporary health status of the Roma in this region. We sought information on the health of the Roma in two of countries with significant Roma minorities, the Czech and Slovak Republics, by means of systematic searches for literature on the health of Roma people published in Czech or Slovak or by authors from the two countries. Published research on health of the Roma population is sparse. The topics that have received attention suggest a focus on concepts of contagion or social Darwinism, indicating a greater concern with the health needs of the majority populations with which they live. What limited evidence exists indicates that the health needs of the Roma population are considerable. With very few exceptions, the health status of Roma is worse than that of non-Roma population in both countries. The burden of communicable disease among Roma is high and diseases associated with poor hygiene seem to be particularly important. Evidence on health care suggests poor communication between Roma and health workers and low uptake of preventative care. The health needs of Roma lack visibility, not only because of the absence of research but also the absence of advocacy on their behalf. Since 1989, Czech and Slovak researchers have largely turned away from health research on particular ethnic groups. This probably reflects a growing sensitivity about stigmatising Roma, but it also makes it difficult to know how their circumstances might be improved. There is a need for further research into the health of Roma people with particular emphasis on non-communicable disease and for interventions that would improve their health.

Reproductive Investment and Health Costs in Roma Women

Directory of Open Access Journals (Sweden)

Jelena Čvorović

2017-11-01

Full Text Available In this paper, we examine whether variation in reproductive investment affects the health of Roma women using a dataset collected through original anthropological fieldwork among Roma women in Serbia. Data were collected in 2014–2016 in several Roma semi-urban settlements in central Serbia. The sample consisted of 468 Roma women, averaging 44 years of age. We collected demographic data (age, school levels, socioeconomic status, risk behaviors (smoking and alcohol consumption, marital status, and reproductive history variables (the timing of reproduction, the intensity of reproduction, reproductive effort and investment after birth, in addition to self-reported health, height, and weight. Data analyses showed that somatic, short-term costs of reproduction were revealed in this population, while evolutionary, long-term costs were unobservable—contrariwise, Roma women in poor health contributed more to the gene pool of the next generation than their healthy counterparts. Our findings appear to be consistent with simple trade-off models that suggest inverse relationships between reproductive effort and health. Thus, personal sacrifice—poor health as an outcome—seems crucial for greater reproductive success.

Multifractal property of Chinese stock market in the CSI 800 index based on MF-DFA approach

Science.gov (United States)

Zhu, Huijian; Zhang, Weiguo

2018-01-01

CSI 800 index consists of CSI 500 index and CSI 300 index, aiming to reflect the performance of stocks with large, mid and small size of China A share market. In this paper we analyze the multifractal structure of Chinese stock market in the CSI 800 index based on the multifractal detrended fluctuation analysis (MF-DFA) method. We find that the fluctuation of the closing logarithmic returns have multifractal properties, the shape and width of multifractal spectrum are depended on the weighing order q. More interestingly, we observe a bigger market crash in June-August 2015 than the one in 2008 based on the local Hurst exponents. The result provides important information for further study on dynamic mechanism of return fluctuation and whether it would trigger a new financial crisis.

Multifractal Detrended Fluctuation Analysis of Human gait Diseases

Directory of Open Access Journals (Sweden)

Srimonti eDutta

2013-10-01

Full Text Available IIn this paper multifractal detrended fluctuation analysis is used to study the human gait time series for normal and diseased sets. It is observed that long range correlation is primarily responsible for the origin of multifractality. The study reveals that the degree of multifractality is more for normal set compared to diseased set. However the method fails to distinguish between the two diseased sets.

Multifractal spectra in shear flows

Science.gov (United States)

Keefe, L. R.; Deane, Anil E.

1989-01-01

Numerical simulations of three-dimensional homogeneous shear flow and fully developed channel flow, are used to calculate the associated multifractal spectra of the energy dissipation field. Only weak parameterization of the results with the nondimensional shear is found, and this only if the flow has reached its asymptotic development state. Multifractal spectra of these flows coincide with those from experiments only at the range alpha less than 1.

Barriers of Roma Women when Accessing into the Labour Market

OpenAIRE

Rác, Ivan; Lehoczká, Lýdia

2016-01-01

The article provides information about barriers of Roma women in the labour market. It analyses the partial results of the project VEGA – Intimate Partner Violence against Roma Women. Most often interpret the entry limits of Roma women in the labour market. Labor et Educatio

Fractal and multifractal analyses of bipartite networks

Science.gov (United States)

Liu, Jin-Long; Wang, Jian; Yu, Zu-Guo; Xie, Xian-Hua

2017-03-01

Bipartite networks have attracted considerable interest in various fields. Fractality and multifractality of unipartite (classical) networks have been studied in recent years, but there is no work to study these properties of bipartite networks. In this paper, we try to unfold the self-similarity structure of bipartite networks by performing the fractal and multifractal analyses for a variety of real-world bipartite network data sets and models. First, we find the fractality in some bipartite networks, including the CiteULike, Netflix, MovieLens (ml-20m), Delicious data sets and (u, v)-flower model. Meanwhile, we observe the shifted power-law or exponential behavior in other several networks. We then focus on the multifractal properties of bipartite networks. Our results indicate that the multifractality exists in those bipartite networks possessing fractality. To capture the inherent attribute of bipartite network with two types different nodes, we give the different weights for the nodes of different classes, and show the existence of multifractality in these node-weighted bipartite networks. In addition, for the data sets with ratings, we modify the two existing algorithms for fractal and multifractal analyses of edge-weighted unipartite networks to study the self-similarity of the corresponding edge-weighted bipartite networks. The results show that our modified algorithms are feasible and can effectively uncover the self-similarity structure of these edge-weighted bipartite networks and their corresponding node-weighted versions.

Health and Roma People in Turkey

Directory of Open Access Journals (Sweden)

Perihan Elif Ekmekçi

2016-08-01

Full Text Available Background: The research and published literatüre on Roma health in Turkey is much more limited than in other European countries. Among these, there are hardly any published literature focusing on the health status, health indicators and health behaviors. Aims: The aim of this research is to describe the perceptions of health-related concepts and access and the use of health services and social determinants of the health of Roma people in Turkey. Study Design: Descriptive qualitative survey. Methods: The participants were chosen by random sampling. The semi-structured interview topic guide was developed from sources such as advice from the Romani community leaders, published evidence and personal experience from previous work with Roma communities. Non-directive open ended questions allowed the exploration of their health status, how they conceptualize health and disease, their level of awareness on the impact of social determinants of health, on their health status and the access and use of health services. The data analysis was based on grounded theory. Analysis proceeded in four steps: 1. Reading and examining the transcripts separately using open coding, 2. Extracting the key words and codes from the transcripts and sorting them into categories, 3. Rereading the transcripts by using selective coding, and 4. Examining the categories derived from the open coding systematically and determining the concepts summarizing the material. Results: The survey results are compatible with the existing literature on Roma health and reveal that 1 there is a tight link between the lack of social determinants of health and the poor health status of Roma people 2 socioeconomic factors and cultural norms of the ethnic minority are suspicious factors 3 comparative and systematic research is needed to illuminate the actual health gaps and causal factors for them. Conclusion: The research proves that the need for comparative and systematic research in Turkey to

Joint multifractal analysis based on wavelet leaders

Science.gov (United States)

Jiang, Zhi-Qiang; Yang, Yan-Hong; Wang, Gang-Jin; Zhou, Wei-Xing

2017-12-01

Mutually interacting components form complex systems and these components usually have long-range cross-correlated outputs. Using wavelet leaders, we propose a method for characterizing the joint multifractal nature of these long-range cross correlations; we call this method joint multifractal analysis based on wavelet leaders (MF-X-WL). We test the validity of the MF-X-WL method by performing extensive numerical experiments on dual binomial measures with multifractal cross correlations and bivariate fractional Brownian motions (bFBMs) with monofractal cross correlations. Both experiments indicate that MF-X-WL is capable of detecting cross correlations in synthetic data with acceptable estimating errors. We also apply the MF-X-WL method to pairs of series from financial markets (returns and volatilities) and online worlds (online numbers of different genders and different societies) and determine intriguing joint multifractal behavior.

Multifractal and higher-dimensional zeta functions

International Nuclear Information System (INIS)

Véhel, Jacques Lévy; Mendivil, Franklin

2011-01-01

In this paper, we generalize the zeta function for a fractal string (as in Lapidus and Frankenhuijsen 2006 Fractal Geometry, Complex Dimensions and Zeta Functions: Geometry and Spectra of Fractal Strings (New York: Springer)) in several directions. We first modify the zeta function to be associated with a sequence of covers instead of the usual definition involving gap lengths. This modified zeta function allows us to define both a multifractal zeta function and a zeta function for higher-dimensional fractal sets. In the multifractal case, the critical exponents of the zeta function ζ(q, s) yield the usual multifractal spectrum of the measure. The presence of complex poles for ζ(q, s) indicates oscillations in the continuous partition function of the measure, and thus gives more refined information about the multifractal spectrum of a measure. In the case of a self-similar set in R n , the modified zeta function yields asymptotic information about both the 'box' counting function of the set and the n-dimensional volume of the ε-dilation of the set

Does the influence of peers and parents on adolescents' drunkenness differ between Roma and non-Roma adolescents in Slovakia?

NARCIS (Netherlands)

Bobakova, D.; Kolarcik, P.; Madarasova-Geckova, A.; Klein, D.; Reijneveld, S.A.; van Dijk, J.P.

2012-01-01

Background. Roma adolescents have been shown to use less alcohol than non-Roma adolescents. This could be due to the protective influences of peers and parents. Objective. The purpose of this study was to explore differences in the levels of peer and parental influence and their effects on

Introduction to the Multifractal Analysis of Images

OpenAIRE

Lévy Véhel , Jacques

1998-01-01

International audience; After a brief review of some classical approaches in image segmentation, the basics of multifractal theory and its application to image analysis are presented. Practical methods for multifractal spectrum estimation are discussed and some experimental results are given.

Multifractal diffusion entropy analysis: Optimal bin width of probability histograms

Science.gov (United States)

Jizba, Petr; Korbel, Jan

2014-11-01

In the framework of Multifractal Diffusion Entropy Analysis we propose a method for choosing an optimal bin-width in histograms generated from underlying probability distributions of interest. The method presented uses techniques of Rényi’s entropy and the mean squared error analysis to discuss the conditions under which the error in the multifractal spectrum estimation is minimal. We illustrate the utility of our approach by focusing on a scaling behavior of financial time series. In particular, we analyze the S&P500 stock index as sampled at a daily rate in the time period 1950-2013. In order to demonstrate a strength of the method proposed we compare the multifractal δ-spectrum for various bin-widths and show the robustness of the method, especially for large values of q. For such values, other methods in use, e.g., those based on moment estimation, tend to fail for heavy-tailed data or data with long correlations. Connection between the δ-spectrum and Rényi’s q parameter is also discussed and elucidated on a simple example of multiscale time series.

Anti-correlation and multifractal features of Spain electricity spot market

NARCIS (Netherlands)

Norouzzadeh, Payam; Dullaert, W.; Rahmani, Bahareh

2007-01-01

We use multifractal detrended fluctuation analysis (MF-DFA) to numerically investigate correlation, persistence, multifractal properties and scaling behavior of the hourly spot prices for the Spain electricity exchange-Compania O Peradora del Mercado de Electricidad (OMEL). Through multifractal

Fractal and multifractal analysis of LiF thin film surface

International Nuclear Information System (INIS)

Yadav, R.P.; Dwivedi, S.; Mittal, A.K.; Kumar, M.; Pandey, A.C.

2012-01-01

Highlights: ► Fractal and multifractal analysis of surface morphologies of the LiF thin films. ► Complexity and roughness of the LiF thin films increases as thickness increases. ► LiF thin films are multifractal in nature. ► Strength of the multifractality increases with thickness of the film. - Abstract: Fractal and multifractal analysis is performed on the atomic force microscopy (AFM) images of the surface morphologies of the LiF thin films of thickness 10 nm, 20 nm, and 40 nm, respectively. Autocorrelation function, height–height correlation function, and two-dimensional multifractal detrended fluctuation analysis (MFDFA) are used for characterizing the surface. It is found that the interface width, average roughness, lateral correlation length, and fractal dimension of the LiF thin film increase with the thickness of the film, whereas the roughness exponent decreases with thickness. Thus, the complexity and roughness of the LiF thin films increases as thickness increases. It is also demonstrated that the LiF thin films are multifractal in nature. Strength of the multifractality increases with thickness of the film.

Beyond Inclusion: Reconsidering Policies, Curriculum, and Pedagogy for Roma Students

Science.gov (United States)

Miskovic, Maja; Curcic, Svjetlana

2016-01-01

This paper investigates the policies and politics of including European Roma students in mainstream educational systems within the context of two European Union (EU) policies: the Decade of Roma Inclusion (2005-2015) and EU National Roma Integration Strategies (2013-2020). Drawing on the scholarship about inclusion and its practical achievements,…

Multifractal Analysis of Asian Foreign Exchange Markets and Financial Crisis

Science.gov (United States)

Oh, Gabjin; Kwon, Okyu; Jung, Woo-Sung

2012-02-01

We analyze the multifractal spectra of daily foreign exchange rates for Japan, Hong-Kong, Korea, and Thailand with respect to the United States Dollar from 1991 to 2005. We find that the return time series show multifractal spectrum features for all four cases. To observe the effect of the Asian currency crisis, we also estimate the multifractal spectra of limited series before and after the crisis. We find that the Korean and Thai foreign exchange markets experienced a significant increase in multifractality compared to Hong-Kong and Japan. We also show that the multifractality is stronge related to the presence of high values of returns in the series.

Submicron scale tissue multifractal anisotropy in polarized laser light scattering

Science.gov (United States)

Das, Nandan Kumar; Dey, Rajib; Chakraborty, Semanti; Panigrahi, Prasanta K.; Meglinski, Igor; Ghosh, Nirmalya

2018-03-01

The spatial fluctuations of the refractive index within biological tissues exhibit multifractal anisotropy, leaving its signature as a spectral linear diattenuation of scattered polarized light. The multifractal anisotropy has been quantitatively assessed by the processing of relevant Mueller matrix elements in the Fourier domain, utilizing the Born approximation and subsequent multifractal analysis. The differential scaling exponent and width of the singularity spectrum appear to be highly sensitive to the structural multifractal anisotropy at the micron/sub-micron length scales. An immediate practical use of these multifractal anisotropy parameters was explored for non-invasive screening of cervical precancerous alterations ex vivo, with the indication of a strong potential for clinical diagnostic purposes.

Testing for multifractality of Islamic stock markets

Science.gov (United States)

Saâdaoui, Foued

2018-04-01

Studying the power-law scaling of financial time series is a promising area of econophysics, which has often contributed to the understanding of the intricate features of the global markets. In this article, we examine the multifractality of some financial processes and the underlying formation mechanisms in the context of Islamic equity markets. The well-known Multifractal Detrended Fluctuation Analysis (MF-DFA) is used to investigate the self-similar properties of two Dow Jones Islamic Market Indexes (DJIM). The results prove that both indexes exhibit multifractal properties. By discussing the sources of multifractality, we find that they are related to the occurrence of extreme events, long-range dependency of autocorrelations and fat-tailed distribution of returns. These results have several important implications for analysts and decision makers in modeling the dynamics of Islamic markets, thus recommending efficient asset allocation plans to investors dealing with Islamic equity markets.

Multifractal Desynchronization of the Cardiac Excitable Cell Network During Atrial Fibrillation. I. Multifractal Analysis of Clinical Data

Directory of Open Access Journals (Sweden)

Guillaume Attuel

2018-03-01

Full Text Available Atrial fibrillation (AF is a cardiac arrhythmia characterized by rapid and irregular atrial electrical activity with a high clinical impact on stroke incidence. Best available therapeutic strategies combine pharmacological and surgical means. But when successful, they do not always prevent long-term relapses. Initial success becomes all the more tricky to achieve as the arrhythmia maintains itself and the pathology evolves into sustained or chronic AF. This raises the open crucial issue of deciphering the mechanisms that govern the onset of AF as well as its perpetuation. In this study, we develop a wavelet-based multi-scale strategy to analyze the electrical activity of human hearts recorded by catheter electrodes, positioned in the coronary sinus (CS, during episodes of AF. We compute the so-called multifractal spectra using two variants of the wavelet transform modulus maxima method, the moment (partition function method and the magnitude cumulant method. Application of these methods to long time series recorded in a patient with chronic AF provides quantitative evidence of the multifractal intermittent nature of the electric energy of passing cardiac impulses at low frequencies, i.e., for times (≳0.5 s longer than the mean interbeat (≃ 10−1 s. We also report the results of a two-point magnitude correlation analysis which infers the absence of a multiplicative time-scale structure underlying multifractal scaling. The electric energy dynamics looks like a “multifractal white noise” with quadratic (log-normal multifractal spectra. These observations challenge concepts of functional reentrant circuits in mechanistic theories of AF, still leaving open the role of the autonomic nervous system (ANS. A transition is indeed observed in the computed multifractal spectra which group according to two distinct areas, consistently with the anatomical substrate binding to the CS, namely the left atrial posterior wall, and the ligament of Marshall

Multifractal Desynchronization of the Cardiac Excitable Cell Network During Atrial Fibrillation. I. Multifractal Analysis of Clinical Data

Science.gov (United States)

Attuel, Guillaume; Gerasimova-Chechkina, Evgeniya; Argoul, Francoise; Yahia, Hussein; Arneodo, Alain

2018-01-01

Atrial fibrillation (AF) is a cardiac arrhythmia characterized by rapid and irregular atrial electrical activity with a high clinical impact on stroke incidence. Best available therapeutic strategies combine pharmacological and surgical means. But when successful, they do not always prevent long-term relapses. Initial success becomes all the more tricky to achieve as the arrhythmia maintains itself and the pathology evolves into sustained or chronic AF. This raises the open crucial issue of deciphering the mechanisms that govern the onset of AF as well as its perpetuation. In this study, we develop a wavelet-based multi-scale strategy to analyze the electrical activity of human hearts recorded by catheter electrodes, positioned in the coronary sinus (CS), during episodes of AF. We compute the so-called multifractal spectra using two variants of the wavelet transform modulus maxima method, the moment (partition function) method and the magnitude cumulant method. Application of these methods to long time series recorded in a patient with chronic AF provides quantitative evidence of the multifractal intermittent nature of the electric energy of passing cardiac impulses at low frequencies, i.e., for times (≳0.5 s) longer than the mean interbeat (≃ 10−1 s). We also report the results of a two-point magnitude correlation analysis which infers the absence of a multiplicative time-scale structure underlying multifractal scaling. The electric energy dynamics looks like a “multifractal white noise” with quadratic (log-normal) multifractal spectra. These observations challenge concepts of functional reentrant circuits in mechanistic theories of AF, still leaving open the role of the autonomic nervous system (ANS). A transition is indeed observed in the computed multifractal spectra which group according to two distinct areas, consistently with the anatomical substrate binding to the CS, namely the left atrial posterior wall, and the ligament of Marshall which is

Multifractal regime transition in a modified minority game model

International Nuclear Information System (INIS)

Crepaldi, Antonio F.; Rodrigues Neto, Camilo; Ferreira, Fernando F.; Francisco, Gerson

2009-01-01

The search for more realistic modeling of financial time series reveals several stylized facts of real markets. In this work we focus on the multifractal properties found in price and index signals. Although the usual minority game (MG) models do not exhibit multifractality, we study here one of its variants that does. We show that the nonsynchronous MG models in the nonergodic phase is multifractal and in this sense, together with other stylized facts, constitute a better modeling tool. Using the structure function (SF) approach we detected the stationary and the scaling range of the time series generated by the MG model and, from the linear (non-linear) behavior of the SF we identified the fractal (multifractal) regimes. Finally, using the wavelet transform modulus maxima (WTMM) technique we obtained its multifractal spectrum width for different dynamical regimes.

Multifractal Analysis for the Teichmueller Flow

Energy Technology Data Exchange (ETDEWEB)

Meson, Alejandro M., E-mail: meson@iflysib.unlp.edu.ar; Vericat, Fernando, E-mail: vericat@iflysib.unlp.edu.ar [Instituto de Fisica de Liquidos y Sistemas Biologicos (IFLYSIB) CCT-CONICET, La Plata-UNLP and Grupo de Aplicaciones Matematicas y Estadisticas de la Facultad de Ingenieria (GAMEFI) UNLP (Argentina)

2012-03-15

We present a multifractal description for Teichmueller flows. A key ingredient to do this is the Rauzy-Veech-Zorich reduction theory, which allows to treat the problem in the setting of suspension flows over subshifts. To perform the multifractal analysis we implement a thermodynamic formalism for suspension flows over countable alphabet subshifts a bit different from that developed by Barreira and Iommi.

Examination Malpractice in Nigeria: Rank-ordering the Types ...

African Journals Online (AJOL)

Although 'giraffing' and carrying of prepared materials into the examination hall were the most common forms of examination malpractice, bribery (ranked 4.5) was the anchor. Students, peer group and parents were the worst malpractitioners in a decreasing order of culpability. Overvaluing of certificates and teachers' ...

Quantum computation of multifractal exponents through the quantum wavelet transform

International Nuclear Information System (INIS)

Garcia-Mata, Ignacio; Giraud, Olivier; Georgeot, Bertrand

2009-01-01

We study the use of the quantum wavelet transform to extract efficiently information about the multifractal exponents for multifractal quantum states. We show that, combined with quantum simulation algorithms, it enables to build quantum algorithms for multifractal exponents with a polynomial gain compared to classical simulations. Numerical results indicate that a rough estimate of fractality could be obtained exponentially fast. Our findings are relevant, e.g., for quantum simulations of multifractal quantum maps and of the Anderson model at the metal-insulator transition.

Multifractal Scaling of Grayscale Patterns: Lacunarity and Correlation Dimension

Science.gov (United States)

Roy, A.; Perfect, E.

2012-12-01

While fractal models can characterize self-similarity in binary fields, comprised solely of 0's and 1's, the concept of multifractals is needed to quantify scaling behavior in non-binary grayscale fields made up of fractional values. Multifractals are characterized by a spectrum of non-integer dimensions, Dq (-∞ < q < +∞) instead of a single fractal dimension. The gliding-box algorithm is sometimes employed to estimate these different dimensions. This algorithm is also commonly used for computing another parameter, lacunarity, L, which characterizes the distribution of gaps or spaces in patterns, fractals, multifractals or otherwise, as a function of scale (or box-size, x). In the case of 2-dimensional multifractal fields, L has been shown to be theoretically related to the correlation dimension, D2, by dlog(L)/dlog(x) = D2 - 2. Therefore, it is hypothesized that lacunarity analysis can help in delineating multifractal behavior in grayscale patterns. In testing this hypothesis, a set of 2-dimensional multifractal grayscale patterns was generated with known D2 values, and then analyzed for lacunarity by employing the gliding-box algorithm. The D2 values computed using this analysis gave a 1:1 relationship with the known D2 values, thus empirically validating the theoretical relationship between L and D2. Lacunarity analysis was further used to evaluate the multifractal nature of natural grayscale images in the form of soil thin sections that had been previously classified as multifractals based on the standard box counting method. The results indicated that lacunarity analysis is a more sensitive indicator of multifractal behavior in natural grayscale patterns than the box counting approach. A weighted mean of the log-transformed lacunarity values at different scales was employed for differentiating between grayscale patterns with various degrees of scale dependent clustering attributes. This new measure, which expresses lacunarity as a single number, should

Daily extreme temperature multifractals in Catalonia (NE Spain)

International Nuclear Information System (INIS)

Burgueño, A.; Lana, X.; Serra, C.; Martínez, M.D.

2014-01-01

The multifractal character of the daily extreme temperatures in Catalonia (NE Spain) is analyzed by means of the multifractal detrended fluctuation analysis (MF-DFA) applied to 65 thermometric records covering years 1950–2004. Although no clear spatial patterns of the multifractal spectrum parameters appear, factor scores deduced from Principal Component analysis indicate some signs of spatial gradients. Additionally, the daily extreme temperature series are classified depending on their complex time behavior, through four multifractal parameters (Hurst exponent, Hölder exponent with maximum spectrum, spectrum asymmetry and spectrum width). As a synthesis of the three last parameters, a basic measure of complexity is proposed through a normalized Complexity Index. Its regional behavior is found to be free of geographical dependences. This index represents a new step towards the description of the daily extreme temperatures complexity.

Daily extreme temperature multifractals in Catalonia (NE Spain)

Energy Technology Data Exchange (ETDEWEB)

Burgueño, A. [Departament d' Astronomia i Meteorologia, Universitat de Barcelona, Barcelona (Spain); Lana, X., E-mail: francisco.javier.lana@upc.edu [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Barcelona (Spain); Serra, C. [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Barcelona (Spain); Martínez, M.D. [Departament de Física Aplicada, Universitat Politècnica de Catalunya, Barcelona (Spain)

2014-02-01

The multifractal character of the daily extreme temperatures in Catalonia (NE Spain) is analyzed by means of the multifractal detrended fluctuation analysis (MF-DFA) applied to 65 thermometric records covering years 1950–2004. Although no clear spatial patterns of the multifractal spectrum parameters appear, factor scores deduced from Principal Component analysis indicate some signs of spatial gradients. Additionally, the daily extreme temperature series are classified depending on their complex time behavior, through four multifractal parameters (Hurst exponent, Hölder exponent with maximum spectrum, spectrum asymmetry and spectrum width). As a synthesis of the three last parameters, a basic measure of complexity is proposed through a normalized Complexity Index. Its regional behavior is found to be free of geographical dependences. This index represents a new step towards the description of the daily extreme temperatures complexity.

MFDFA and Lacunarity Analysis of Synthetic Multifractals and Pre-Cancerous Tissues

Science.gov (United States)

Roy, A.; Das, N.; Ghosh, N.

2017-12-01

Multifractal Detrended Fluctuation Analysis (MFDFA) has been employed for evaluating complex variations in the refractive index (RI) of human pre-cancerous tissues. While this was primarily aimed towards the early diagnosis of cancer in the human cervix, question remains whether multifractal analysis alone can be conclusively used for distinguishing between various grades of pre-cancerous tissues. Lacunarity is a parameter that was developed for multiscale analysis of data and has been shown to be theoretically related to the correlation dimension, D2, by dlog(L)/dlog(x) = D2 - 2. Further, research has proven that not only can Lacunarity be used as a preliminary indicator of multifractal behavior but it also distinguishes between images with similar correlation dimension values. In order to compare the efficacy of the two approaches namely, MFDFA and Lacunarity, in distinguishing between pre-cancerous tissues of various grades, we test these techniques on a set of 2-dimensional theoretical random multifractal fields. MFDFA is employed for computing the width of the singularity spectrum f(α), which is a measure of multifractal behavior. A weighted mean of the log-transformed lacunarity values at different scales is employed for differentiating between patterns with the same correlation dimension but differences in texture. The two different techniques are then applied to images containing RI values of biopsy samples from human cervical tissues that were histo-pathologically characterized as grade-I and grade-II pre-cancerous cells. The results show that the two approaches are complementary to one another when it comes to multi-scale analysis of complex natural patterns manifested in the images of such pre-cancerous cells.

Statistical and Multifractal Evaluation of Soil Compaction in a Vineyard

Science.gov (United States)

Marinho, M.; Raposo, J. R.; Mirás Avalos, J. M.; Paz González, A.

2012-04-01

.5% higher than along the vine row. Vine row and outside-track positions showed not significant differences between means. The bulk density of the wheel-track transect also showed the lowest CV. The multifractal spectra of the three transects were asymmetric curves, rather short toward the left and much longer toward the right. The width of the right deviating shaped multifractal spectra was ranked as: wine row > outside-track ≈ wheel-track. Entropy dimension, D1, was 0.998, 0.992 and 0.992 for vine row, outside-track and track transects, respectively. These results show different patterns of variability of bulk density for parallel transects. They also suggest that multifractal parameters may be useful in assessing the variability of other soil properties such as soil particle density, soil porosity or soil water content, at different spatial scales as well. Acknowledgments. This work was funded in part by Spanish Ministry of Science and Innovation (MICINN) in the frame of project CGL2009-13700-C02. Financial support from CAPES/GOV., Brazil, is also acknowledged by Prof. M. Marinho.

Health Behaviors, Nutritional Status, and Anthropometric Parameters of Roma and Non-Roma Mothers and Their Infants in the Czech Republic

Science.gov (United States)

Rambouskova, Jolana; Dlouhy, Pavel; Krizova, Eva; Prochazka, Bohumir; Hrncirova, Dana; Andel, M

2009-01-01

Objective: To compare maternal health behaviors, maternal nutritional status, and infant size at birth of Romas and non-Romas in the Czech Republic. Design: Maternal interviews and food frequency questionnaire, maternal blood samples, physical measurements of mothers and infants. Setting: Hospital, maternal/child care center; 2-4 days postpartum.…

Frames for exact inversion of the rank order coder.

Science.gov (United States)

Masmoudi, Khaled; Antonini, Marc; Kornprobst, Pierre

2012-02-01

Our goal is to revisit rank order coding by proposing an original exact decoding procedure for it. Rank order coding was proposed by Thorpe et al. who stated that the order in which the retina cells are activated encodes for the visual stimulus. Based on this idea, the authors proposed in [1] a rank order coder/decoder associated to a retinal model. Though, it appeared that the decoding procedure employed yields reconstruction errors that limit the model bit-cost/quality performances when used as an image codec. The attempts made in the literature to overcome this issue are time consuming and alter the coding procedure, or are lacking mathematical support and feasibility for standard size images. Here we solve this problem in an original fashion by using the frames theory, where a frame of a vector space designates an extension for the notion of basis. Our contribution is twofold. First, we prove that the analyzing filter bank considered is a frame, and then we define the corresponding dual frame that is necessary for the exact image reconstruction. Second, to deal with the problem of memory overhead, we design a recursive out-of-core blockwise algorithm for the computation of this dual frame. Our work provides a mathematical formalism for the retinal model under study and defines a simple and exact reverse transform for it with over than 265 dB of increase in the peak signal-to-noise ratio quality compared to [1]. Furthermore, the framework presented here can be extended to several models of the visual cortical areas using redundant representations.

Multifractal analysis of forest fires in complex regions

Science.gov (United States)

Vega Orozco, C. D.; Kanevski, M.; Golay, J.; Tonini, M.; Conedera, M.

2012-04-01

Forest fires can be studied as point processes where the ignition points represent the set of locations of the observed events in a defined study region. Their spatial and temporal patterns can be characterized by their fractal properties; which quantify the global aspect of the geometry of the support data. However, a monofractal dimension can not completely describe the pattern structure and related scaling properties. Enhancements in fractal theory had developed the multifractal concept which describes the measures from which interlinked fractal sets can be retrieved and characterized by their fractal dimension and singularity strength [1, 2]. The spatial variability of forest fires is conditioned by an intermixture of human, topographic, meteorological and vegetation factors. This heterogeneity makes fire patterns complex scale-invariant processes difficult to be depicted by a single scale. Therefore, this study proposes an exploratory data analysis through a multifractal formalism to characterize and quantify the multiscaling behaviour of the spatial distribution pattern of this phenomenon in a complex region like the Swiss Alps. The studied dataset is represented by 2,401 georeferenced forest fire ignition points in canton Ticino, Switzerland, in a 40-years period from 1969 to 2008. Three multifractal analyses are performed: one assesses the multiscaling behaviour of fire occurrence probability of the support data (raw data) and four random patterns simulated within three different support domains; second analysis studies the multifractal behavior of patterns from anthropogenic and natural ignited fires (arson-, accident- and lightning-caused fires); and third analysis aims at detecting scale-dependency of the size of burned area. To calculate the generalized dimensions, Dq, a generalization of the box counting methods is carried out based on the generalization of Rényi information of the qth order moment of the probability distribution. For q > 0, Dq

Collective identity and wellbeing of Roma minority adolescents in Bulgaria.

Science.gov (United States)

Dimitrova, Radosveta; Chasiotis, Athanasios; Bender, Michael; van de Vijver, Fons

2013-01-01

In Europe and particularly in Bulgaria, Roma represent the largest low-status minority group that is subjected to marked public intolerance and discrimination. This study examined links among Roma (N = 207) and Bulgarian (N = 399) adolescents' ethnic, familial, and religious identities as salient identity aspects for their psychological wellbeing. Results indicated that, as expected, Roma youth reported lower levels of wellbeing than Bulgarian youth. The latter revealed a weaker religious identity than Roma youth, whereas no ethnic group differences emerged regarding Bulgarian or familial identity. Furthermore, we observed that collective identity was higher in older participants of both groups. Finally, a multigroup analysis using structural equation modeling showed that collective identity was a positive predictor of wellbeing for both Roma and Bulgarian adolescents. Findings demonstrated differences in salience as well as structural communalities regarding ways in which collective identity affects wellbeing of youth from two ethnically diverse communities.

High values of disorder-generated multifractals and logarithmically correlated processes

International Nuclear Information System (INIS)

Fyodorov, Yan V.; Giraud, Olivier

2015-01-01

In the introductory section of the article we give a brief account of recent insights into statistics of high and extreme values of disorder-generated multifractals following a recent work by the first author with P. Le Doussal and A. Rosso (FLR) employing a close relation between multifractality and logarithmically correlated random fields. We then substantiate some aspects of the FLR approach analytically for multifractal eigenvectors in the Ruijsenaars–Schneider ensemble (RSE) of random matrices introduced by E. Bogomolny and the second author by providing an ab initio calculation that reveals hidden logarithmic correlations at the background of the disorder-generated multifractality. In the rest we investigate numerically a few representative models of that class, including the study of the highest component of multifractal eigenvectors in the Ruijsenaars–Schneider ensemble

Natality and infant mortality in Roma children in the Prešov region

Directory of Open Access Journals (Sweden)

Ján Koval

2012-06-01

Full Text Available Background: Due to the lack of exact data on natality and infant mortality rates of the Roma living in Slovakia we aim to look closer into these parameters, analyze them and in this respect compare two ethnic groups: Roma and non-Roma Slovak children. Material and methods: In the time period from 1997 to 2011, we collected data in selected parameters (birth rate, infant mortality rate, the number of newborns with low birth weight, the number of children abandoned by their mothers after birth in the Prešov region, and we evaluated them. Findings: A declining natality rate was observed in non-Roma children, as opposed to an upward trend in Roma children. In 1997, every fourth child was born to a Roma woman; in 2011, it was every third child. A declining infant mortality rate was observed in all groups studied. In the Roma children, the decline in the infant mortality rate was the biggest, yet the mere infant mortality rate, in this group of children, was the highest – in 1997 and in 2011 approximately 3-times higher than in the children born to non-Roma mothers. Conclusion: In our study, the infant mortality rate of Roma children is on decline, yet still it is high when compared to the non-Roma population. This may be caused by low interest of the Roma in providing health care to their children and their low responsibility or their inability to take responsibility for health and health care education of their children.

Multifractal vector fields and stochastic Clifford algebra.

Science.gov (United States)

Schertzer, Daniel; Tchiguirinskaia, Ioulia

2015-12-01

In the mid 1980s, the development of multifractal concepts and techniques was an important breakthrough for complex system analysis and simulation, in particular, in turbulence and hydrology. Multifractals indeed aimed to track and simulate the scaling singularities of the underlying equations instead of relying on numerical, scale truncated simulations or on simplified conceptual models. However, this development has been rather limited to deal with scalar fields, whereas most of the fields of interest are vector-valued or even manifold-valued. We show in this paper that the combination of stable Lévy processes with Clifford algebra is a good candidate to bridge up the present gap between theory and applications. We show that it indeed defines a convenient framework to generate multifractal vector fields, possibly multifractal manifold-valued fields, based on a few fundamental and complementary properties of Lévy processes and Clifford algebra. In particular, the vector structure of these algebra is much more tractable than the manifold structure of symmetry groups while the Lévy stability grants a given statistical universality.

Multifractal vector fields and stochastic Clifford algebra

Energy Technology Data Exchange (ETDEWEB)

Schertzer, Daniel, E-mail: Daniel.Schertzer@enpc.fr; Tchiguirinskaia, Ioulia, E-mail: Ioulia.Tchiguirinskaia@enpc.fr [University Paris-Est, Ecole des Ponts ParisTech, Hydrology Meteorology and Complexity HM& Co, Marne-la-Vallée (France)

2015-12-15

In the mid 1980s, the development of multifractal concepts and techniques was an important breakthrough for complex system analysis and simulation, in particular, in turbulence and hydrology. Multifractals indeed aimed to track and simulate the scaling singularities of the underlying equations instead of relying on numerical, scale truncated simulations or on simplified conceptual models. However, this development has been rather limited to deal with scalar fields, whereas most of the fields of interest are vector-valued or even manifold-valued. We show in this paper that the combination of stable Lévy processes with Clifford algebra is a good candidate to bridge up the present gap between theory and applications. We show that it indeed defines a convenient framework to generate multifractal vector fields, possibly multifractal manifold-valued fields, based on a few fundamental and complementary properties of Lévy processes and Clifford algebra. In particular, the vector structure of these algebra is much more tractable than the manifold structure of symmetry groups while the Lévy stability grants a given statistical universality.

Introduction to multifractal detrended fluctuation analysis in matlab.

Science.gov (United States)

Ihlen, Espen A F

2012-01-01

Fractal structures are found in biomedical time series from a wide range of physiological phenomena. The multifractal spectrum identifies the deviations in fractal structure within time periods with large and small fluctuations. The present tutorial is an introduction to multifractal detrended fluctuation analysis (MFDFA) that estimates the multifractal spectrum of biomedical time series. The tutorial presents MFDFA step-by-step in an interactive Matlab session. All Matlab tools needed are available in Introduction to MFDFA folder at the website www.ntnu.edu/inm/geri/software. MFDFA are introduced in Matlab code boxes where the reader can employ pieces of, or the entire MFDFA to example time series. After introducing MFDFA, the tutorial discusses the best practice of MFDFA in biomedical signal processing. The main aim of the tutorial is to give the reader a simple self-sustained guide to the implementation of MFDFA and interpretation of the resulting multifractal spectra.

Influence of Age and Aerobic Fitness on the Multifractal Characteristics of Electrocardiographic RR Time-Series

Directory of Open Access Journals (Sweden)

Michael James Lewis

2013-05-01

Full Text Available Multifractal properties of electrocardiographic inter-beat (RR time-series offer insight into its long-term correlation structure, independently of RR variability. Here we quantify multifractal characteristics of RR data during 24-hour diurnal-nocturnal activity in healthy participants. We tested the hypotheses that (1 age, gender and aerobic fitness influence RR multifractal properties, and that (2 these are influenced by circadian variation.Seventy adults (39 males aged 19-58 years and of various fitness levels were monitored using 24-hour ECG. Participants were dichotomised by median age and fitness for sub-group analysis. Gender and fitness were independent of age (p=0.1, p>0.5. Younger/older group ages were substantially different (p<0.0005 and were independent of gender and fitness. Multifractality was quantified using the probability spectrum of Hölder exponents (h, from which modal h (h* and the full-width and half-widths at half-maximum measures (FWHM, HWHM+ and HWHM- were derived. FWHM decreased (p=0.004 and h* increased (p=0.011 in older people, indicating diminished long-range RR correlations and weaker anti-persistent behavior. Anti-persistent correlation (h* was strongest in the youngest/fittest individuals and weakest in the oldest/least fit individuals (p=0.015. Long-range correlation (HWHM+/FWHM was strongest in the fittest males and weakest in the least fit females (p=0.007-0.033.Multifractal RR characteristics in our healthy participants showed strong age-dependence with diminished long-range anti-persistent correlation in older people. Circadian variation of these characteristics was influenced by fitness and gender: fitter males and females of all ages had the greatest degree of multifractality or long-range order. Multifractal characterisation appears to be a useful method for exploring the physiological basis of long-term correlation structure in RR time-series as well as the benefits thereon of physical fitness training.

Contraceptive Attitudes and Practices in the Roma Communities

Directory of Open Access Journals (Sweden)

Raluca Zanca

2009-12-01

Full Text Available The process of adopting a contraceptive behaviour is determined by a series of factors, having a slow progress in time. The use of birth control methods by the Roma women is influenced by a series of specific elements. This article wants to highlight an image containing the degree in which the Roma women are aware of the birth control methods and family planning. To this end, I have used the technique of group interview. In the first stage I applied a number of group interviews on the Roma women from the Gîrcin community. Afterwards I examined the interviews using inductive analysis. The results were grouped into thematic categories.

Multifractals of investor behavior in stock market

Science.gov (United States)

Oh, Gabjin

2017-07-01

In this paper, we analyze the nonlinear properties of investor activity using the multifractal detrended fluctuation analysis (MF-DFA) method. Using the aggregated trading volumes of buying, selling, and normalized net investor trading (NIT) to quantify the characteristics of trader behavior in the KOSPI market, we find that the cumulative distribution functions of all NIT time series, except for individual traders, follow a power-law distribution with an exponent in the range of 2.92 ≤ γ ≤ 3.87. To observe the nonlinear features of investor activity, we also calculate the multifractal spectra for the buyer, seller, and NIT data sets and find that a multifractal structure exists in all of the data, regardless of the investor type studied.

Correlation and multifractality in climatological time series

International Nuclear Information System (INIS)

Pedron, I T

2010-01-01

Climate can be described by statistical analysis of mean values of atmospheric variables over a period. It is possible to detect correlations in climatological time series and to classify its behavior. In this work the Hurst exponent, which can characterize correlation and persistence in time series, is obtained by using the Detrended Fluctuation Analysis (DFA) method. Data series of temperature, precipitation, humidity, solar radiation, wind speed, maximum squall, atmospheric pressure and randomic series are studied. Furthermore, the multifractality of such series is analyzed applying the Multifractal Detrended Fluctuation Analysis (MF-DFA) method. The results indicate presence of correlation (persistent character) in all climatological series and multifractality as well. A larger set of data, and longer, could provide better results indicating the universality of the exponents.

Multifractal analysis of Moroccan family business stock returns

Science.gov (United States)

Lahmiri, Salim

2017-11-01

In this paper, long-range temporal correlations at different scales in Moroccan family business stock returns are investigated. For comparison purpose, presence of multifractality is also investigated in Casablanca Stock Exchange (CSE) major indices: MASI which is the all shares index and MADEX which is the index of most liquid shares. It is found that return series of both family business companies and major stock market indices show strong evidence of multifractality. In particular, empirical results reveal that short (long) fluctuations in family business stock returns are less (more) persistent (anti-persistent) than short fluctuations in market indices. In addition, both serial correlation and distribution characteristics significantly influence the strength of the multifractal spectrums of CSE and family business stocks returns. Furthermore, results from multifractal spectrum analysis suggest that family business stocks are less risky. Thus, such differences in price dynamics could be exploited by investors and forecasters in active portfolio management.

Analyzing the Cross-Correlation Between Onshore and Offshore RMB Exchange Rates Based on Multifractal Detrended Cross-Correlation Analysis (MF-DCCA)

Science.gov (United States)

Xie, Chi; Zhou, Yingying; Wang, Gangjin; Yan, Xinguo

We use the multifractal detrended cross-correlation analysis (MF-DCCA) method to explore the multifractal behavior of the cross-correlation between exchange rates of onshore RMB (CNY) and offshore RMB (CNH) against US dollar (USD). The empirical data are daily prices of CNY/USD and CNH/USD from May 1, 2012 to February 29, 2016. The results demonstrate that: (i) the cross-correlation between CNY/USD and CNH/USD is persistent and its fluctuation is smaller when the order of fluctuation function is negative than that when the order is positive; (ii) the multifractal behavior of the cross-correlation between CNY/USD and CNH/USD is significant during the sample period; (iii) the dynamic Hurst exponents obtained by the rolling windows analysis show that the cross-correlation is stable when the global economic situation is good and volatile in bad situation; and (iv) the non-normal distribution of original data has a greater effect on the multifractality of the cross-correlation between CNY/USD and CNH/USD than the temporary correlation.

Affirmative Action in Romania's Higher Education: Roma Students' Perceived Meanings and Dilemmas

Science.gov (United States)

Pantea, Maria-Carmen

2015-01-01

This qualitative paper explores Roma students' perceptions on the policy of assigning "special places" for Roma in Romania's universities. Findings suggest that Roma see themselves as occupying a precarious social space, concerned not as much to hide perceived merit violation but to handle (alleged) inadequacies given by their…

Roma Empowerment and Social Inclusion Through Work-Integrated Learning

DEFF Research Database (Denmark)

Eklund Karlsson, Leena; Crondahl, Kristine

2015-01-01

The basis for this article was a health promotion program based on participatory action research and work-integrated learning (WIL). Seven Roma people were employed and trained to work as local coordinators to empower the local Roma community by strengthening their participation in society and th...

Multifractal structure of multiplicity distributions and negative binomials

International Nuclear Information System (INIS)

Malik, S.; Delhi, Univ.

1997-01-01

The paper presents experimental results of the multifractal structure analysis in proton-emulsion interactions at 800 GeV. The multiplicity moments have a power law dependence on the mean multiplicity in varying bin sizes of pseudorapidity. The values of generalised dimensions are calculated from the slope value. The multifractal characteristics are also examined in the light of negative binomials. The observed multiplicity moments and those derived from the negative-binomial fits agree well with each other. Also the values of D q , both observed and derived from the negative-binomial fits not only decrease with q typifying multifractality but also agree well each other showing consistency with the negative-binomial form

Application of third order stochastic dominance algorithm in investments ranking

Directory of Open Access Journals (Sweden)

Lončar Sanja

2012-01-01

Full Text Available The paper presents the use of third order stochastic dominance in ranking Investment alternatives, using TSD algorithms (Levy, 2006for testing third order stochastic dominance. The main goal of using TSD rule is minimization of efficient investment set for investor with risk aversion, who prefers more money and likes positive skew ness.

The medical social centres in support of Roma in Greece

DEFF Research Database (Denmark)

Andrioti, Despena; Kotrotsou, Christina; Tsakatara, Vanta

2013-01-01

. Medical social centres operate in 33 Roma settlements all over the country. These centres provide vaccination, health promotion, disease prevention and health education services, as well as support in issuing documents and making appointments with health and social services. We recommend that the National......Roma people form the largest ethnic-minority group in Europe. They account for around 10 to 12 million people, and they face racism, discrimination and social exclusion in most countries. The Roma population of Greece currently numbers around 250 000 individuals. They have Greek nationality...... and enjoy the same rights, privileges and responsibilities as any other Greek citizens. Nevertheless, Roma in Greece face multiple inequalities and social exclusion in terms of housing, employment, education, and health and social services. In this report we present the outcome of a bestpractice initiative...

Multifractals embedded in short time series: An unbiased estimation of probability moment

Science.gov (United States)

Qiu, Lu; Yang, Tianguang; Yin, Yanhua; Gu, Changgui; Yang, Huijie

2016-12-01

An exact estimation of probability moments is the base for several essential concepts, such as the multifractals, the Tsallis entropy, and the transfer entropy. By means of approximation theory we propose a new method called factorial-moment-based estimation of probability moments. Theoretical prediction and computational results show that it can provide us an unbiased estimation of the probability moments of continuous order. Calculations on probability redistribution model verify that it can extract exactly multifractal behaviors from several hundred recordings. Its powerfulness in monitoring evolution of scaling behaviors is exemplified by two empirical cases, i.e., the gait time series for fast, normal, and slow trials of a healthy volunteer, and the closing price series for Shanghai stock market. By using short time series with several hundred lengths, a comparison with the well-established tools displays significant advantages of its performance over the other methods. The factorial-moment-based estimation can evaluate correctly the scaling behaviors in a scale range about three generations wider than the multifractal detrended fluctuation analysis and the basic estimation. The estimation of partition function given by the wavelet transform modulus maxima has unacceptable fluctuations. Besides the scaling invariance focused in the present paper, the proposed factorial moment of continuous order can find its various uses, such as finding nonextensive behaviors of a complex system and reconstructing the causality relationship network between elements of a complex system.

Entropy and Multifractality in Relativistic Ion-Ion Collisions

Directory of Open Access Journals (Sweden)

Shaista Khan

2018-01-01

Full Text Available Entropy production in multiparticle systems is investigated by analyzing the experimental data on ion-ion collisions at AGS and SPS energies and comparing the findings with those reported earlier for hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions. It is observed that the entropy produced in limited and full phase space, when normalized to maximum rapidity, exhibits a kind of scaling which is nicely supported by Monte Carlo model HIJING. Using Rényi’s order q information entropy, multifractal characteristics of particle production are examined in terms of generalized dimensions, Dq. Nearly the same values of multifractal specific heat, c, observed in hadronic and ion-ion collisions over a wide range of incident energies suggest that the quantity c might be used as a universal characteristic of multiparticle production in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions. The analysis is extended to the study of spectrum of scaling indices. The findings reveal that Rényi’s order q information entropy could be another way to investigate the fluctuations in multiplicity distributions in terms of spectral function f(α, which has been argued to be a convenient function for comparison sake not only among different experiments but also between the data and theoretical models.

Origin of differences between Serbian and Roma children in social intelligence test's achievement

Directory of Open Access Journals (Sweden)

Đigić Gordana

2008-01-01

Full Text Available The goal of the presented research is to identify the origin of differences between Serbian (N=166 and Roma children (N=169 of primary school age in achievement on Modified Rosenzweig Test, used as a measure of social intelligence (Roma children had lower results than Serbian children. Results show that these differences can be partly explained with extreme inviolable socio-economic and cultural status of Roma children. Social intelligence test's scores are significantly correlated with socio-economic and cultural status; this correlation is more apparent in Roma than in Serbian sample. Differences between Serbian and Roma children become less apparent when we control the influence of socio-economic and cultural status. Parent's educational level is recognized as the most important indicator of socio-economic and cultural status. Another way to identify the origin of differences was directed to investigation of adequacy of used test as a measure of social intelligence of Roma children. Our assumption that some items make whole test unfair for Roma children is not confirmed. However, results concerning the relation between experience with particular social situations and success in particular test items, and results concerning the different structures of implicite understanding of social intelligence by Serbian and Roma parents, point out that test key favors responses that Serbian people accept as optimal in task situation, while the responses according to Roma implicite understanding of social intelligence are less valued.

Multifractal analysis of three-dimensional histogram from color images

International Nuclear Information System (INIS)

Chauveau, Julien; Rousseau, David; Richard, Paul; Chapeau-Blondeau, Francois

2010-01-01

Natural images, especially color or multicomponent images, are complex information-carrying signals. To contribute to the characterization of this complexity, we investigate the possibility of multiscale organization in the colorimetric structure of natural images. This is realized by means of a multifractal analysis applied to the three-dimensional histogram from natural color images. The observed behaviors are confronted to those of reference models with known multifractal properties. We use for this purpose synthetic random images with trivial monofractal behavior, and multidimensional multiplicative cascades known for their actual multifractal behavior. The behaviors observed on natural images exhibit similarities with those of the multifractal multiplicative cascades and display the signature of elaborate multiscale organizations stemming from the histograms of natural color images. This type of characterization of colorimetric properties can be helpful to various tasks of digital image processing, as for instance modeling, classification, indexing.

Multifractal detrended cross-correlation analysis in the MENA area

Science.gov (United States)

El Alaoui, Marwane; Benbachir, Saâd

2013-12-01

In this paper, we investigated multifractal cross-correlations qualitatively and quantitatively using a cross-correlation test and the Multifractal detrended cross-correlation analysis method (MF-DCCA) for markets in the MENA area. We used cross-correlation coefficients to measure the level of this correlation. The analysis concerns four stock market indices of Morocco, Tunisia, Egypt and Jordan. The countries chosen are signatory of the Agadir agreement concerning the establishment of a free trade area comprising Arab Mediterranean countries. We computed the bivariate generalized Hurst exponent, Rényi exponent and spectrum of singularity for each pair of indices to measure quantitatively the cross-correlations. By analyzing the results, we found the existence of multifractal cross-correlations between all of these markets. We compared the spectrum width of these indices; we also found which pair of indices has a strong multifractal cross-correlation.

Involvement of Roma Parents in Children's Education in Croatia: A Comparative Study

Science.gov (United States)

Pahic, Tea; Vidovic, Vlasta Vizek; Miljevic-Ridicki, Renata

2011-01-01

This article compares Roma and mainstream parents' involvement in the education of their children, based on Epstein's six-dimensional model of parent-school partnership. The survey was conducted in Croatia on two sub-samples: 60 Roma parents and 908 mainstream parents. Results suggest that Roma parents show lower interest in participating in…

Discourses of Roma Anti-Discrimination in Reports on Human Rights Violations

Directory of Open Access Journals (Sweden)

Chloë Delcour

2015-09-01

Full Text Available In an effort to understand the paradox between the expansion of inclusion projects for the Roma and their persisting exclusion, this article explores human rights practice in order to grasp the complexity of meanings of inclusion negotiated in this practice. In this way, we scrutinize whether there are limiting factors within the inclusionary discourse itself. Specifically, we analyze the discourse in transnational judicial, political and civil society actors’ reports on violations of human rights against Roma. A strong shared tendency to frame the violations in terms of discrimination can be discerned in the reports, demonstrating a dominant concept in the human rights discourse for Roma. However, a framing analysis of the underlying assumptions of this concept shows that not all three actors offer the same solutions for obtaining non-discrimination, which can partly explain the limited impact of the ostensibly strong and inclusive anti-discrimination discourse. In contrast, the actors do share a negative attribution of responsibility to the nation states, but the effectiveness of this shared discursive claim can be questioned. This article illustrates how inclusion discourses are actually quite complex to grasp and so it substantiates the need for greater critical understanding of such discourses in further research.

Dynamical Mechanism of Scaling Behaviors in Multifractal Structure

Science.gov (United States)

Kim, Kyungsik; Jung, Jae Won; Kim, Soo Yong

2010-03-01

The pattern of stone distribution in the game of Go (Baduk, Weiqi, or Igo) can be treated in the mathematical and physical languages of multifractals. The concepts of fractals and multifractals have relevance to many fields of science and even arts. A significant and fascinating feature of this approach is that it provides a proper interpretation for the pattern of the two-colored (black and white) stones in terms of the numerical values of the generalized dimension and the scaling exponent. For our case, these statistical quantities can be estimated numerically from the black, white, and mixed stones, assuming the excluded edge effect that the cell form of the Go game has the self-similar structure. The result from the multifractal structure allows us to find a definite and reliable fractal dimension, and it precisely verifies that the fractal dimension becomes larger, as the cell of grids increases. We also find the strength of multifractal structures from the difference in the scaling exponents in the black, white, and mixed stones.

From Research to Policy: Roma Participation through Communicative Organization

Science.gov (United States)

Munte, Ariadna; Serradell, Olga; Sorde, Teresa

2011-01-01

For centuries, Roma people's social exclusion has been reinforced through research that has legitimized stereotypes rather than helping to overcome them. This has led Roma people to refuse to participate in the kind of research that has contributed to discrimination against them. We describe how the critical communicative methodology, used in the…

Roma Education on the Agenda of the European Union

Science.gov (United States)

Jaroka, Livia

2007-01-01

The Roma community of Europe continues to face discrimination in a number of areas, notably education, employment, healthcare, and housing. In an increasingly knowledge-based economy, education provides one of the primary tools for escaping the cycle of poverty that traps many Roma families, and therefore it is one of the most pressing issues that…

Institutional Racism? Roma Children, Local Community and School Practices

Science.gov (United States)

Zachos, Dimitris

2012-01-01

This article tries to discuss the conditions Roma pupils face within the Greek educational system. In the first part, through a brief history of Roma groups in Greece followed by a short analysis of their legal status and leaving conditions, I attempt to present a critical approach in Romani Studies. Thereafter, using Institutional Racism as a…

The Multifractal Structure of Small-Scale Artificial Ionospheric Turbulence

Directory of Open Access Journals (Sweden)

Vybornov F. I.

2013-03-01

Full Text Available We present the results of investigation of a multifractal structure of the artificial ionospheric turbulence when the midlatitude ionosphere is affected by high-power radio waves. The experimental studies were performed on the basis of the SURA heating facility with the help of radio sounding of the disturbed region of ionospheric plasma by signals from the Earth’s orbital satellities. In the case of vertical radio sounding of the disturbed ionosphere region, the measured multipower and generalized multifractal spectra of turbulence coincide well with similar multifractal characteristics of the ionosperic turbulence under the natural conditions. In the case of oblique sounding of the disturbance region at small angles between the line of sight to the satellite and the direction of the Earth’s magnetic field, a nonuniform structure of the small-scale turbulence with a relatively narrow multipower spectrum and small variations in the generalized multifractal spectrum of the electron density was detected.

ROMA: representation and quantification of module activity from target expression data

Directory of Open Access Journals (Sweden)

Loredana eMartignetti

2016-02-01

Full Text Available In many analysis of high-throughput data in systems biology, there is a need to quantify the activity of a set of genes in individual samples. A typical example is the case where it is necessary to estimate the activity of a transcription factor (which is often not directly measurable from the expression of its target genes. We present here ROMA (Representation and quantification Of Module Activities Java software, designed for fast and robust computation of the activity of gene sets (or modules with coordinated expression. ROMA activity quantification is based on the simplest uni-factor linear model of gene regulation that approximates the expression data of a gene set by its first principal component.The proposed algorithm implements novel functionalities: it provides several method modifications for principal components computation, including weighted, robust and centered methods; it distinguishes overdispersed modules (based on the variance explained by the first principal component and coordinated modules (based on the significance of the spectral gap; finally, it computes statistical significance of the estimated module overdispersion or coordination.ROMA can be applied in many contexts, from estimating differential activities of transcriptional factors to findingoverdispersed pathways in single-cell transcriptomics data. We describe here the principles of ROMA providing several practical examples of its use.ROMA source code is available at https://github.com/sysbio-curie/Roma.

The Roma in Hungary: The Situation and Perspectives on the Threshhold of the 21st Century

Directory of Open Access Journals (Sweden)

Boris Nikšić

2004-12-01

Full Text Available In this paper the author examines the situation of the Roma minority in present-day Hungary. First he gives a short overview, summarizing Roma history in all of Europe from the time of their arrival, especially in regard to Hungary. He presents general information on the language and on some cultural-civilisational traits of the Roma in the past and compares former assimilational tendencies formulated in the atmosphere of enlightened absolutism with similar tendencies that appeared and were implemented in many European countries in the more recent period. The author directs special attention to the economic, social and educational aspects of the Roma theme in Hungary, and presents some indications concerning the images the Hungarian majority has of the Roma minority. To a certain degree he analyses the structure of prejudices towards the Roma, in relation to the social strata from which they come. Most of his data derives from research conducted on the theme of the Roma in Hungary during the last fifteen years. The question of the educational structure of the Roma population is analysed primarily in regard to how much it enables employment. A poor educational structure and the impossibility to find employment are indicated as the main problems preventing the full integration of the Roma into present-day Hungarian society. Finally, the author analyses the role of civil society associations in resolving the problems of the Roma, with a special note on strictly Roma organisations as forms of minority self-government. Some examples are given also of the penetration of modern mass culture into the collective cultural identificational code of the Roma minority. These cultural elements, alongside Roma traditions that are still maintained and nurtured, help to increase the self-consciousness of the Roma, but they also stimulate interests in the rest of the population and in this way sensitivise the general population towards the Roma theme.

Multifractal in Volatility of Family Business Stocks Listed on Casablanca STOCK Exchange

Science.gov (United States)

Lahmiri, Salim

In this paper, we check for existence of multifractal in volatility of Moroccan family business stock returns and in volatility of Casablanca market index returns based on multifractal detrended fluctuation analysis (MF-DFA) technique. Empirical results show strong evidence of multifractal characteristics in volatility series of both family business stocks and market index. In addition, it is found that small variations in volatility of family business stocks are persistent, whilst small variations in volatility of market index are anti-persistent. However, large variations in family business volatility and market index volatility are both anti-persistent. Furthermore, multifractal spectral analysis based results show strong evidence that volatility in Moroccan family business companies exhibits more multifractality than volatility in the main stock market. These results may provide insightful information for risk managers concerned with family business stocks.

Low rank approach to computing first and higher order derivatives using automatic differentiation

International Nuclear Information System (INIS)

Reed, J. A.; Abdel-Khalik, H. S.; Utke, J.

2012-01-01

This manuscript outlines a new approach for increasing the efficiency of applying automatic differentiation (AD) to large scale computational models. By using the principles of the Efficient Subspace Method (ESM), low rank approximations of the derivatives for first and higher orders can be calculated using minimized computational resources. The output obtained from nuclear reactor calculations typically has a much smaller numerical rank compared to the number of inputs and outputs. This rank deficiency can be exploited to reduce the number of derivatives that need to be calculated using AD. The effective rank can be determined according to ESM by computing derivatives with AD at random inputs. Reduced or pseudo variables are then defined and new derivatives are calculated with respect to the pseudo variables. Two different AD packages are used: OpenAD and Rapsodia. OpenAD is used to determine the effective rank and the subspace that contains the derivatives. Rapsodia is then used to calculate derivatives with respect to the pseudo variables for the desired order. The overall approach is applied to two simple problems and to MATWS, a safety code for sodium cooled reactors. (authors)

Multifractal signal reconstruction based on singularity power spectrum

International Nuclear Information System (INIS)

Xiong, Gang; Yu, Wenxian; Xia, Wenxiang; Zhang, Shuning

2016-01-01

Highlights: • We propose a novel multifractal reconstruction method based on singularity power spectrum analysis (MFR-SPS). • The proposed MFR-SPS method has better power characteristic than the algorithm in Fraclab. • Further, the SPS-ISE algorithm performs better than the SPS-MFS algorithm. • Based on the proposed MFR-SPS method, we can restructure singularity white fractal noise (SWFN) and linear singularity modulation (LSM) multifractal signal, in equivalent sense, similar with the linear frequency modulation(LFM) signal and WGN in the Fourier domain. - Abstract: Fractal reconstruction (FR) and multifractal reconstruction (MFR) can be considered as the inverse problem of singularity spectrum analysis, and it is challenging to reconstruct fractal signal in accord with multifractal spectrum (MFS). Due to the multiple solutions of fractal reconstruction, the traditional methods of FR/MFR, such as FBM based method, wavelet based method, random wavelet series, fail to reconstruct fractal signal deterministically, and besides, those methods neglect the power spectral distribution in the singular domain. In this paper, we propose a novel MFR method based singularity power spectrum (SPS). Supposing the consistent uniform covering of multifractal measurement, we control the traditional power law of each scale of wavelet coefficients based on the instantaneous singularity exponents (ISE) or MFS, simultaneously control the singularity power law based on the SPS, and deduce the principle and algorithm of MFR based on SPS. Reconstruction simulation and error analysis of estimated ISE, MFS and SPS show the effectiveness and the improvement of the proposed methods compared to those obtained by the Fraclab package.

Los edificios deportivos de la Roma Antigua

Directory of Open Access Journals (Sweden)

Angela TEJA

2013-11-01

Full Text Available La educación física y el deporte retrocedió —en la Roma antigua— respecto a los ideales físico-corporales griegos. Por contra, se fomentó una notable cultura de espectáculos y divertimentos, especialmente durante la época imperial. A fin de dar cobijo a los diversos espectáculos se construyeron en la ciudad de Roma —y por mimetismo en todas las urbes del Imperio— sofisticados edificios. En efecto, además de una importante red de circos —el más emblemático de los cuales fue el circo Máximo—, se levantaron anfiteatros y termas, amén del estadio de Dominiciano. La autora pasa revista a las distintas instalaciones «deportivas» de la Roma antigua, así como a los espectáculos que albergaban: las carreras del circo, los combates de gladiadores, las cacerías de fieras, las naumaquias, sin olvidar las competiciones del estadio y la pasión romana por las termas.

[Contraception in the Roma population living in two low-income neighborhoods of Barcelona (Spain)].

Science.gov (United States)

Asensio, Alba; Nebot, Laia; Estruga, Lluïsa; Perez, Glòria; Diez, Èlia

2018-02-22

To describe the knowledge and use of contraceptive methods and health services in the Roma population (Kale/Spanish Gitanos) of two low-income neighbourhoods of Barcelona (2011-2015). Mixed. Community setting. 1) Descriptive cross-sectional study. We interviewed with a questionnaire a sample of residents of childbearing age. We compared the knowledge and use of contraception and services by ethnic self-identification and sex with adjusted logistic regression models to obtain adjusted odds ratio (ORa) and 95% confidence interval (95%CI). 2) Qualitative descriptive study with ethnographic method. We interviewed 10 Roma residents and three health professionals to explore aspects of contraception, family and roles. We performed a narrative analysis of discourse from the recorded texts. 834 people participated, with an 11.8% self-identified Roma population. With regard to the non-Roma population, more Roma women used tubal ligation (ORa: 3.0; 95%CI: 1.3-7)] and implant (ORa:4.9; 95%CI: 3.1-72), and had better knowledge of IUD (ORa: 2,4; 95%CI: 1,4-4,1), tubal obstruction (ORa: 3,3; 95%CI: 1,1-9,9) and injectables (ORa: 2,4; 95%CI: 1.3-4.4). Roma men used withdrawal more frequently (ORa: 3.6; 95%CI: 1.3-10), a practice confirmed in the qualitative study. Both communities used emergency contraception and health services. In the Roma population, contraception and reproduction are in the hands of women. As abortion is culturally penalized in the Roma population, women use it, but they face it alone. Gender emerged as a cross-cutting determinant in all issues explored. In the Roma population reproductive control and contraception remain the responsibility of women. Once the family is complete, Roma women use long-term contraception. Both populations use health services. Copyright © 2018 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

A Smoothing Technique for the Multifractal Analysis of a Medium Voltage Feeders Electric Current

Science.gov (United States)

de Santis, Enrico; Sadeghian, Alireza; Rizzi, Antonello

2017-12-01

The current paper presents a data-driven detrending technique allowing to smooth complex sinusoidal trends from a real-world electric load time series before applying the Detrended Multifractal Fluctuation Analysis (MFDFA). The algorithm we call Smoothed Sort and Cut Fourier Detrending (SSC-FD) is based on a suitable smoothing of high power periodicities operating directly in the Fourier spectrum through a polynomial fitting technique of the DFT. The main aim consists of disambiguating the characteristic slow varying periodicities, that can impair the MFDFA analysis, from the residual signal in order to study its correlation properties. The algorithm performances are evaluated on a simple benchmark test consisting of a persistent series where the Hurst exponent is known, with superimposed ten sinusoidal harmonics. Moreover, the behavior of the algorithm parameters is assessed computing the MFDFA on the well-known sunspot data, whose correlation characteristics are reported in literature. In both cases, the SSC-FD method eliminates the apparent crossover induced by the synthetic and natural periodicities. Results are compared with some existing detrending methods within the MFDFA paradigm. Finally, a study of the multifractal characteristics of the electric load time series detrendended by the SSC-FD algorithm is provided, showing a strong persistent behavior and an appreciable amplitude of the multifractal spectrum that allows to conclude that the series at hand has multifractal characteristics.

CULTURAL IDENTITY AND CITIZENSHIP. THE CASE OF THE ROMA MINORITY IN ROMANIA

Directory of Open Access Journals (Sweden)

VALENTIN QUINTUS NICOLESCU

2011-04-01

Full Text Available My paper focuses on the intersection between the Roma cultural-identitary construction and the political concept of citizenship, trying to reveal if such an approach can prove itself helpful in providing a better understanding of the unilaterality of the majority-Roma relationship. By unilaterality I understand the particular model in which the Roma-Romanian relationship has structured itself overtime. It mainly consists of a segregationist view that stresses the majority’s responsibility with the minority’s integration process and the failures to promote a partnership with the minority. This approach tends, in my opinion, to treat the minority in absentia, producing therefore the well-known effects of the so-called “Roma problem”. On the other hand, the idea of empowering the Roma minority is also seen as being fundamentally within the majority’s attributions, therefore contradicting the very essence of the concept. My approach seeks to apply a theoretical framework developed first by Gramsci and later by Boudieu to this particular situation. Thus I hope to be able to provide a better understanding of both the history and the present of majority-minority relations and to highlight possible directions or outcomes relating to the dichotomy of integration/communitarian privacy in the case of the Roma minority.

Inconvenient Human Rights: Water and Sanitation in Sweden's Informal Roma Settlements.

Science.gov (United States)

Davis, Martha F; Ryan, Natasha

2017-12-01

Following an increase in Roma migration under the European "freedom of movement" laws, Swedish municipalities initiated more than 80 evictions of informal Roma settlements on the grounds of poor sanitation between 2013 and 2016. These evictions echo policies from earlier in the 20th century, when Roma living in Sweden were often marginalized through the denial of access to water and sanitation facilities. The recent Swedish evictions also follow similar government actions across Europe, where Roma settlements are controlled through the denial of access to water and sanitation. However, access to water and sanitation-central aspects of human health-are universal human rights that must be available to all people present in a jurisdiction, regardless of their legal status. The evictions described here violated Sweden's obligations under both European and international human rights law. More positive government responses are required, such as providing shelters or camping sites, setting up temporary facilities, and directly engaging with communities to address water and sanitation issues. The authors conclude by providing guidance on how states and municipalities can meet their human rights obligations with respect to water and sanitation for vulnerable Roma individuals and informal settlements in their communities.

Multi-fractal analysis of highway traffic data

Institute of Scientific and Technical Information of China (English)

Shang Peng-Jian; Shen Jin-Sheng

2007-01-01

The purpose of the present study is to investigate the presence of multi-fractal behaviours in the traffic time series not only by statistical approaches but also by geometrical approaches. The pointwise H(o)lder exponent of a function is calculated by developing an algorithm for the numerical evaluation of H(o)lder exponent of time series. The traffic time series observed on the Beijing Yuquanying highway are analysed. The results from all these methods indicate that the traffic data exhibit the multi-fractal behaviour.

Otherness in Pedagogical Theory and Practice: The Case of Roma

Science.gov (United States)

Kirova, Anna; Prochner, Larry

2015-01-01

This paper addresses the topic of the inclusion of Roma children in education in Europe through an examination of theory and practice in relation to the issues of Otherness and foreignness. Roma children entering school encounter a vastly different world from their home culture, with different expectations for teaching and learning, for…

Hate Speech or Genocidal Discourse? An Examination of Anti-Roma Sentiment in Contemporary Europe

Directory of Open Access Journals (Sweden)

Emma Townsend

2014-08-01

Full Text Available Roma in contemporary Europe are the frequent targets of hate speech and discriminatory state policies. Despite being the largest minority in the European Union with a population of 10-12 million, they are frequently denied a space in European society, and are widely perceived to be unchangeable and inherently ‘other’. As a result, Roma experience substantially inferior life conditions when compared to majority European populations. Despite the many recent European Union initiatives and action plans, such as the Decade of Roma Inclusion (2005-2015, the situation of Roma in contemporary Europe is not improving, and in some cases is actually worsening. This persecution is not a modern phenomenon; Roma have suffered stigmatisation and exclusion throughout their history in Europe. The severity and continuity of the persecution of Roma at the hands of a multitude of European authorities suggests the presence of an underlying motivation or intent that informs both the rhetoric about and treatment of Romani people. This paper will examine if the persecution of Roma in contemporary Europe is guided by a genocidal discourse. To this end, the boundaries between hate speech, genocidal discourse, and incitement to genocide will be scrutinised. It will be argued that both the way the Roma are spoken about and the treatment they receive are informed by a genocidal discourse that has endured relatively unchanged throughout their history in Europe. Roma are not just racially vilified, rather their culture as well as their physical presence in contemporary Europe are widely devalued in both words and in state action. Any improvement in their situation is therefore unlikely while this discourse continues.

Uma Times Square para Roma. Construções da cidade de Roma em produções midiáticas

OpenAIRE

Menezes, Victor Henrique da Silva

2015-01-01

O presente trabalho tem como objetivo tecer algumas considerações acerca da forma como a cidade de Roma do século I. a.C foi representada no seriado Roma (2005- 2007), produzido pelas redes de televisão HBO, BBC e RAI. Para tal, serão destacados alguns cenários e imagens apresentados na série, inspirados em centros urbanos modernos, bem como depoimentos de produtores, diretores e consultores de história que atuaram em sua produção. Por fim, serão ressaltadas algumas das possíveis influências ...

Why Roma Children Need Language Asessments in Romani

Directory of Open Access Journals (Sweden)

Kyuchukov Hristo

2017-11-01

Full Text Available In this paper we make one major point: that Roma children in Europe need to be tested in their mother tongue before school placement. Roma children are in a particularly perilous position with respect to their education. We describe the problematic linguistic situation of Roma children, who are bilingual and often bidialectal, but are frequently evaluated in the language of the state for educational placement, a process that has been shown to significantly compromise their chance of success. We then review the considerable empirical evidence that bilingual children must be evaluated in both languages to give a fair assessment of their knowledge and skills. Furthermore, strength in the mother tongue has demonstrable transfer to skills in the second language. We provide a brief summary of a new assessment for Romani that has been used successfully to evaluate children aged 3 to 6 years, and present the results of a new study using it in Slovakia on 29 children aged 3 to 6 years.

Asymmetric multi-fractality in the U.S. stock indices using index-based model of A-MFDFA

International Nuclear Information System (INIS)

Lee, Minhyuk; Song, Jae Wook; Park, Ji Hwan; Chang, Woojin

2017-01-01

Highlights: • ‘Index-based A-MFDFA’ model is proposed to assess the asymmetric multi-fractality. • The asymmetric multi-fractality in the U.S. stock indices are investigated using ‘Index-based’ and ‘Return-based’ A-MFDFA. • The asymmetric feature is more significantly identified by ‘Index-based’ model than ‘return-based’ model. • Source of multi-fractality and time-varying features are analyzed. - Abstract: We detect the asymmetric multi-fractality in the U.S. stock indices based on the asymmetric multi-fractal detrended fluctuation analysis (A-MFDFA). Instead using the conventional return-based approach, we propose the index-based model of A-MFDFA where the trend based on the evolution of stock index rather than stock price return plays a role for evaluating the asymmetric scaling behaviors. The results show that the multi-fractal behaviors of the U.S. stock indices are asymmetric and the index-based model detects the asymmetric multi-fractality better than return-based model. We also discuss the source of multi-fractality and its asymmetry and observe that the multi-fractal asymmetry in the U.S. stock indices has a time-varying feature where the degree of multi-fractality and asymmetry increase during the financial crisis.

Increasing Critical Health Literacy of Roma People trough Participatory Action Research

DEFF Research Database (Denmark)

Eklund Karlsson, Leena; Crondahl, Kristine

to take a leading role in their integration process a 2-year action research was implemented in 2010-2012. The idea was to strengthen the Roma Peoples’ critical health literacy which allows them to analyze and apply health information to oppose the forces that are holding them oppressed and to take better...... control over their life situation. The objective of this paper is to discuss methodological issues based on experiences of the use of participatory research approach in increasing health literacy. Methods: The core of the intervention was ‘training of trainers’ of a group of Roma people from western....... Conclusions: The Roma participants’ strengthened critical health literacy improved their health chances and possibilities for participation in working life and decision making on Roma issues. The existing system of rules for project operations clashed with the character of the “soft” bottom-up approach...

True and apparent scaling: The proximity of the Markov-switching multifractal model to long-range dependence

Science.gov (United States)

Liu, Ruipeng; Di Matteo, T.; Lux, Thomas

2007-09-01

In this paper, we consider daily financial data of a collection of different stock market indices, exchange rates, and interest rates, and we analyze their multi-scaling properties by estimating a simple specification of the Markov-switching multifractal (MSM) model. In order to see how well the estimated model captures the temporal dependence of the data, we estimate and compare the scaling exponents H(q) (for q=1,2) for both empirical data and simulated data of the MSM model. In most cases the multifractal model appears to generate ‘apparent’ long memory in agreement with the empirical scaling laws.

The health of the Roma people: a review of the published literature.

Science.gov (United States)

Hajioff, S; McKee, M

2000-11-01

The Roma people originated in northern India and have been known in Europe for nearly a thousand years. For much of that time they have been the subjects of discrimination and oppression, culminating in the extermination of half a million Roma in the Nazi death camps. While it is widely believed that the health of Roma people is often poorer than the majority population, these inequalities remain largely unresearched. Published literature on the health of the Roma people was identified using Medline. Opinion pieces were excluded, as were papers relating to anthropometry and to genetic markers. The resultant papers were analysed by country of study and by disease type or care group. Some 70% of papers identified related to just three countries; Spain and the Czech and Slovak Republics. Much literature concentrates upon communicable disease or reproductive health. The limited evidence suggests increased morbidity from non-communicable disease, but there is little published on this topic. Evidence on health care, though fragmentary, suggests poorer access to health services and uptake of preventative care. Published research on the health needs of the Roma population is sparse. The topics that have received attention suggest a focus on concepts of contagion or social Darwinism, indicating a greater concern with the health needs of the majority populations with which they live. There is a need for both further research into the health of Roma people; with particular emphasis on non-communicable disease; and also for interventions that improve Roma health. Such research must, however, be handled with sensitivity, recognising the social and political context of the society concerned.

Cross-Correlations between Energy and Emissions Markets: New Evidence from Fractal and Multifractal Analysis

Directory of Open Access Journals (Sweden)

Gang-Jin Wang

2014-01-01

Full Text Available We supply a new perspective to describe and understand the behavior of cross-correlations between energy and emissions markets. Namely, we investigate cross-correlations between oil and gas (Oil-Gas, oil and CO2 (Oil-CO2, and gas and CO2 (Gas-CO2 based on fractal and multifractal analysis. We focus our study on returns of the oil, gas, and CO2 during the period of April 22, 2005–April 30, 2013. In the empirical analysis, by using the detrended cross-correlation analysis (DCCA method, we find that cross-correlations for Oil-Gas, Oil-CO2, and Gas-CO2 obey a power-law and are weakly persistent. Then, we adopt the method of DCCA cross-correlation coefficient to quantify cross-correlations between energy and emissions markets. The results show that their cross-correlations are diverse at different time scales. Next, based on the multifractal DCCA method, we find that cross-correlated markets have the nonlinear and multifractal nature and that the multifractality strength for three cross-correlated markets is arranged in the order of Gas-CO2 > Oil-Gas > Oil-CO2. Finally, by employing the rolling windows method, which can be used to investigate time-varying cross-correlation scaling exponents, we analyze short-term and long-term market dynamics and find that the recent global financial crisis has a notable influence on short-term and long-term market dynamics.

Qualification of Food Intake by the Roma Population in the Region of South Bohemia

Directory of Open Access Journals (Sweden)

Lenka Sedova

2018-02-01

Full Text Available The article presents the results of a correlation study, aimed at quantifying the food intake of the Roma population in the South Bohemian Region. To achieve the goal, we applied the method of one-day dietary recall and frequency food analysis (non-standardized. The quantification was carried out by analysis in the Nutridan program. The study involved 302 Roma persons and 298 persons in the control group. Both groups had the same representation of males and females (50:50. The age categories of both sets differed; the average age of the Roma was lower (39.2 years (p < 0.001. The probands from the Roma population were chosen with the help of the snowball method through known respondents. The statistical analysis shows differences in nutritional estimate between the Roma population and the control sample. The Roma differ in their energy intake. Both groups showed lower intake of sugars, below 50% total energy intake (TEI and higher intake of fats, above 30% TEI. The respondents from both groups consume little fruits and vegetables, which may be connected with their low dietary fiber intake. In addition to the differences in the nutritional estimates, we recorded statistically significant differences in body mass index (BMI; p < 0.001, in age (p < 0.001, regular alimentation (p = 0 and demanding physical activities (p = 0. In spite of the fact our groups differed in age (the Roma are younger, it can be assumed that the obesity of the Roma may be caused by unbalanced alimentation and lack of physical activities.

“Village-making in the city”: Communities of Roma migrants and anti-Gypsyism in Geneva

Directory of Open Access Journals (Sweden)

Monica Battaglini

2017-07-01

Full Text Available The present article, developed out of a research project which lasted several years, analyses the tensions between, on one side, Romanian Roma back-and-forth migrants, and on the other side, Geneva's police. In the last decade, these tensions are mostly linked to begging (an activity which provides small daily incomes to the majority of the 250 Romanian Roma living in the city, that is since 2007 a crime. These tensions between police officers and Roma are part of a wider European punishing-the-poor urban governance model, and bring to the exclusion of other actors from the public action. Through the interaction between the moral and symbolic violence linked to police intervention, the high visibility of Roma in public place and their reconnection with previous experiences, such tensions re-create the ethnic divide between Roma and non-Roma. As a consequence, Roma who have their roots in rural and peri-urban Transylvania use their “village making” practices to perform a symbolic and social appropriation of the town notwithstanding “anti-Gypsy” repression. The “village making” of the Roma becomes thus a specific form of response in a context  (Geneva and more generally Switzerland where the occupation of urban and peri-urban territory through the “camps” experienced in other European towns does not exist.

Exploring the social relations of Roma employability: The case of rural segregated communities in Romania

Directory of Open Access Journals (Sweden)

Loreni Elena Baciu

2016-04-01

Full Text Available The article reports on a qualitative study of Roma employability in Romania. Being the largest ethnic minority group in Europe, the Roma population is the object of profound marginalization in most of the countries where they reside, by measures such as spatial segregation and exclusion from the formal labour market. This article focuses particularly on the Roma living in rural segregated communities. Inspired by institutional ethnography, the aim is to explore the social organization of rural Roma employability from the standpoint of the Roma themselves. The main obstacles to employment, as they are known and shared by our interviewees, are a lack of available jobs within reach, their own lack of education and a rejection by employers on the grounds of them being Roma. As the analyses show, these obstacles, and the individual’s experiences and knowledge about them, are shaped and maintained by extended translocal relations of administration and governance, thus making the rural Roma dependent on a precarious secondary labour market of low-paid day work for neighbouring farmers. The uncertainty of this work, and the organization and work of everyday life it implies for the people inhabiting these communities, further increases the distance to formal employment. It is this complex set of relations coordinating people’s doings that produce the employability of Roma inhabiting the rural segregated communities.

Regularities of Multifractal Measures

Indian Academy of Sciences (India)

First, we prove the decomposition theorem for the regularities of multifractal Hausdorff measure and packing measure in R R d . This decomposition theorem enables us to split a set into regular and irregular parts, so that we can analyze each separately, and recombine them without affecting density properties. Next, we ...

Knowledge extraction from evolving spiking neural networks with rank order population coding.

Science.gov (United States)

Soltic, Snjezana; Kasabov, Nikola

2010-12-01

This paper demonstrates how knowledge can be extracted from evolving spiking neural networks with rank order population coding. Knowledge discovery is a very important feature of intelligent systems. Yet, a disproportionally small amount of research is centered on the issue of knowledge extraction from spiking neural networks which are considered to be the third generation of artificial neural networks. The lack of knowledge representation compatibility is becoming a major detriment to end users of these networks. We show that a high-level knowledge can be obtained from evolving spiking neural networks. More specifically, we propose a method for fuzzy rule extraction from an evolving spiking network with rank order population coding. The proposed method was used for knowledge discovery on two benchmark taste recognition problems where the knowledge learnt by an evolving spiking neural network was extracted in the form of zero-order Takagi-Sugeno fuzzy IF-THEN rules.

Multifractal Detrended Cross-Correlation Analysis of agricultural futures markets

International Nuclear Information System (INIS)

He Lingyun; Chen Shupeng

2011-01-01

Highlights: → We investigated cross-correlations between China's and US agricultural futures markets. → Power-law cross-correlations are found between the geographically far but correlated markets. → Multifractal features are significant in all the markets. → Cross-correlation exponent is less than averaged GHE when q 0. - Abstract: We investigated geographically far but temporally correlated China's and US agricultural futures markets. We found that there exists a power-law cross-correlation between them, and that multifractal features are significant in all the markets. It is very interesting that the geographically far markets show strong cross-correlations and share much of their multifractal structure. Furthermore, we found that for all the agricultural futures markets in our studies, the cross-correlation exponent is less than the averaged generalized Hurst exponents (GHE) when q 0.

Socioeconomic characteristics of the population living in Roma settlements and their association with health and health-related behaviour.

Science.gov (United States)

Gecková, Andrea Madarasová; Babinská, Ingrid; Bobáková, Daniela; Veselská, Zuzana Dankulincová; Bosáková, Lucia; Kolarcik, Peter; Jarcuska, Peter; Pella, Daniel; Halánová, Monika

2014-03-01

The aim of this study was to compare socioeconomic characteristics of the Roma population living in Roma settlements with the majority population. Moreover, it was aimed to assess socioeconomic differences in health and health-related behaviour within the population living in Roma settlements. Data from the cross-sectional HepaMeta study conducted in Slovakia in 2011 were used. The sample consisted of 452 Roma (mean age = 34.7; 35.2% men) and 403 non-Roma (mean age = 33.5; 45.9% men) respondents. Roma in selected settlements were recruited by local Roma community workers. Respondents from the major population were randomly selected from a list of patients from general practitioners. Data were collected via questionnaire, anthropometric measures and analysed blood samples. Differences in socioeconomic characteristics between the population living in Roma settlements and the majority population were tested using the chi-square test. The contribution of selected socioeconomic characteristics on health and health-related behaviour of the population living in Roma settlements was assessed by logistic regression models adjusted for age and gender. The population living in Roma settlements is characterised by significantly lower socioeconomic standards, and the living conditions are significantly worse compared with the majority. With few exceptions, the study did not confirm any significant association between socioeconomic indicators and health and health-related behaviour within the population living in Roma settlements. The deteriorating effect of living in Roma settlement on health and health-related behaviour seems to be immense regardless differences in socioeconomic characteristics or living condition within the settlement population.

The weather and climate: emergent laws and multifractal cascades

Science.gov (United States)

Lovejoy, Shaun; Schertzer, Daniel

2013-04-01

Science in general and physics and geophysics in particular are hierarchies of interlocking theories and models with low level, fundamental laws such as quantum mechanics and statistical mechanics providing the underpinnings for the emergence of the qualitatively new, higher level laws of thermodynamics and continuum mechanics that provide the current bases for modelling the weather and climate. Yest it was the belief of generations of turbulence pioneers (notably Richardson, Kolmogorov, Obhukhov, Corrsin, Bolgiano) that at sufficiently high levels of nonlinearity (quantified by the Reynold's number, of the order 10**12 in the atmosphere) that new even higher level laws would emerge describing "fully developed turbulence". However for atmospheric applications, the pioneers' eponymous laws suffered from two basic restrictions - isotropy and homogeneity - that prevented them from being valid over wide ranges of scale. Over the last thirty years both of these restrictions have been overcome - the former with the generalization from isotropic to strongly anisotropic notions of scale (to account notably for stratification), and from homogeneity to strong heterogeneity (intermittency) via multifractal cascades. In this presentation we give an overview of recent developments and analyses covering huge ranges of space-time scales (including weather, macroweather and climate time scales). We show how the combination of strong anisotropy and strong intermittency commonly leads to the "phenomenological fallacy" in which morphology is confounded with mechanism. With the help of stochastic models, we show how processes with vastly different large and small scale morphologies can arise from a unique multifractal dynamical mechanisms [Lovejoy and Schertzer, 2013]. References: Lovejoy, S., and D. Schertzer (2013), The Weather and Climate: Emergent Laws and Multifractal Cascades, 480 pp., Cambridge University Press, Cambridge.

Improved moment scaling estimation for multifractal signals

Directory of Open Access Journals (Sweden)

D. Veneziano

2009-11-01

Full Text Available A fundamental problem in the analysis of multifractal processes is to estimate the scaling exponent K(q of moments of different order q from data. Conventional estimators use the empirical moments μ^_r^q=⟨ | ε_r(τ|^q⟩ of wavelet coefficients ε_r(τ, where τ is location and r is resolution. For stationary measures one usually considers "wavelets of order 0" (averages, whereas for functions with multifractal increments one must use wavelets of order at least 1. One obtains K^(q as the slope of log( μ^_r^q against log(r over a range of r. Negative moments are sensitive to measurement noise and quantization. For them, one typically uses only the local maxima of | ε_r(τ| (modulus maxima methods. For the positive moments, we modify the standard estimator K^(q to significantly reduce its variance at the expense of a modest increase in the bias. This is done by separately estimating K(q from sub-records and averaging the results. For the negative moments, we show that the standard modulus maxima estimator is biased and, in the case of additive noise or quantization, is not applicable with wavelets of order 1 or higher. For these cases we propose alternative estimators. We also consider the fitting of parametric models of K(q and show how, by splitting the record into sub-records as indicated above, the accuracy of standard methods can be significantly improved.

Comparison of the health of Roma and non-Roma children living in the district of Teplice

Czech Academy of Sciences Publication Activity Database

Dostál, Miroslav; Topinka, Jan; Šrám, Radim

2010-01-01

Roč. 55, č. 5 (2010), s. 435-441 ISSN 1661-8556 Institutional research plan: CEZ:AV0Z50390512 Keywords : Roma children * health * morbidity Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 2.241, year: 2010

Multifractal properties of diffusion-limited aggregates and random multiplicative processes

International Nuclear Information System (INIS)

Canessa, E.

1991-04-01

We consider the multifractal properties of irreversible diffusion-limited aggregation (DLA) from the point of view of the self-similarity of fluctuations in random multiplicative processes. In particular we analyse the breakdown of multifractal behaviour and phase transition associated with the negative moments of the growth probabilities in DLA. (author). 20 refs, 5 figs

Roma in Serbia after the Collapse of Yugoslavia: Political implications and media silence on racial violence

Directory of Open Access Journals (Sweden)

Nataša SIMEUNOVIĆ BAJIĆ

2011-12-01

Full Text Available This paper attempts to clarify the Roma issue in Serbia. Media representations of attacks against Roma are very important. The Roma are marginalized members of Serbian society. They are often the victims of violence and discrimination that are related to stereotypes and prejudice about Roma ”otherness”. The media paid special attention to the murder of Duško Jovanović in 1997 because it was the first official murder based on racial hatred. This case study shows that the topics of the assassination of the Roma are no more attractive to the media and that the “spiral of silence” occupies an important role.

Coupled uncertainty provided by a multifractal random walker

International Nuclear Information System (INIS)

Koohi Lai, Z.; Vasheghani Farahani, S.; Movahed, S.M.S.; Jafari, G.R.

2015-01-01

The aim here is to study the concept of pairing multifractality between time series possessing non-Gaussian distributions. The increasing number of rare events creates “criticality”. We show how the pairing between two series is affected by rare events, which we call “coupled criticality”. A method is proposed for studying the coupled criticality born out of the interaction between two series, using the bivariate multifractal random walk (BiMRW). This method allows studying dependence of the coupled criticality on the criticality of each individual system. This approach is applied to data sets of gold and oil markets, and inflation and unemployment. - Highlights: • The coupled criticality between two systems is modeled by the bivariate multifractal random walk. • This coupled criticality is generally directed. • This coupled criticality is inversely proportional to the criticality of either of the systems. • The coupled criticality can emerge when at least one of the systems posses a Gaussian distribution

Super-Resolution Reconstruction of Remote Sensing Images Using Multifractal Analysis

Directory of Open Access Journals (Sweden)

Mao-Gui Hu

2009-10-01

Full Text Available Satellite remote sensing (RS is an important contributor to Earth observation, providing various kinds of imagery every day, but low spatial resolution remains a critical bottleneck in a lot of applications, restricting higher spatial resolution analysis (e.g., intraurban. In this study, a multifractal-based super-resolution reconstruction method is proposed to alleviate this problem. The multifractal characteristic is common in Nature. The self-similarity or self-affinity presented in the image is useful to estimate details at larger and smaller scales than the original. We first look for the presence of multifractal characteristics in the images. Then we estimate parameters of the information transfer function and noise of the low resolution image. Finally, a noise-free, spatial resolutionenhanced image is generated by a fractal coding-based denoising and downscaling method. The empirical case shows that the reconstructed super-resolution image performs well indetail enhancement. This method is not only useful for remote sensing in investigating Earth, but also for other images with multifractal characteristics.

Influence of urban morphology on total noise pollution: multifractal description.

Science.gov (United States)

Ariza-Villaverde, Ana B; Jiménez-Hornero, Francisco J; Gutiérrez De Ravé, Eduardo

2014-02-15

Exposure to ambient noise levels above 65 dB can cause public health problems. The spatial distribution of this kind of pollution is linked to various elements which make up the urban form, such as construction density, the existence of open spaces and the shape and physical position of buildings. Since urban morphology displays multifractal behaviour, the present research studies for the first time the relationship between total noise pollution and urban features, such as street width and building height by means of a joint multifractal spectrum in two neighbourhoods of the city of Cordoba (Andalusia, Spain). According to the results, the joint multifractal spectrum reveals a positive correlation between the total noise pollution and the street width to building height ratio, this being more evident when urban morphology is regular. The information provided by the multifractal analysis completes the description obtained by using urban indexes and landscape metrics and might be useful for urban planning once the linkage between both frameworks has been done. Copyright © 2013 Elsevier B.V. All rights reserved.

Healthier lives for European minority groups: school and health care, lessons from the Roma.

Science.gov (United States)

Flecha, Ainhoa

2013-07-24

On average, the Roma in Europe can expect to die 10 years earlier than the rest of the population, given the health conditions they experience. EU-funded research has informed on successful actions (SA) that when implemented among the Roma provide them new forms of educational participation which have a direct impact on improving their health status, regardless of their educational level. The findings from this research, unanimously endorsed by the European Parliament, have been included in several European Union recommendations and resolutions as part of the EU strategy on Roma inclusion. To analyze these SA, as well as the conditions that promote them and their impact on reducing health inequalities, communicative fieldwork has been conducted with Roma people from a deprived neighbourhood in the South of Spain, who are participating in the previously identified SA. The analysis reveals that these SA enable Roma people to reinforce and enrich specific strategies like improving family cohesion and strengthening their identity, which allow them to improve their overall health. These findings may inform public policies to improve the health condition of the Roma and other vulnerable groups, one goal of the Europe 2020 strategy for a healthier Europe.

Multifractal characterisation and classification of bread crumb digital images

OpenAIRE

Baravalle, Rodrigo Guillermo; Delrieux, Claudio Augusto; Gómez, Juan Carlos

2017-01-01

Adequate models of the bread crumb structure can be critical for understanding flow and transport processes in bread manufacturing, creating synthetic bread crumb images for photo-realistic rendering, evaluating similarities, and establishing quality features of different bread crumb types. In this article, multifractal analysis, employing the multifractal spectrum (MFS), has been applied to study the structure of the bread crumb in four varieties of bread (baguette, sliced, bran, and sandwic...

Variability of multifractal parameters in an urban precipitation monitoring network

Science.gov (United States)

Licznar, Paweł; De Michele, Carlo; Dżugaj, Dagmara; Niesobska, Maria

2014-05-01

Precipitation especially over urban areas is considered a highly non-linear process, with wide variability over a broad range of temporal and spatial scales. Despite obvious limitations of rainfall gauges location at urban sites, rainfall monitoring by gauge networks is a standard solution of urban hydrology. Often urban precipitation gauge networks are formed by modern electronic gauges and connected to control units of centralized urban drainage systems. Precipitation data, recorded online through these gauge networks, are used in so called Real-Time-Control (RTC) systems for the development of optimal strategies of urban drainage outflows management. As a matter of fact, the operation of RTC systems is motivated mainly by the urge of reducing the severity of urban floods and combined sewerage overflows, but at the same time, it creates new valuable precipitation data sources. The variability of precipitation process could be achieved by investigating multifractal behavior displayed by the temporal structure of precipitation data. There are multiply scientific communications concerning multifractal properties of point-rainfall data from different worldwide locations. However, very little is known about the close variability of multifractal parameters among closely located gauges, at the distances of single kilometers. Having this in mind, here we assess the variability of multifractal parameters among gauges of the urban precipitation monitoring network in Warsaw, Poland. We base our analysis on the set of 1-minute rainfall time series recorded in the period 2008-2011 by 25 electronic weighing type gauges deployed around the city by the Municipal Water Supply and Sewerage Company in Warsaw as a part of local RTC system. The presence of scale invariance and multifractal properties in the precipitation process was investigated with spectral analysis, functional box counting method and studying the probability distributions and statistical moments of the rainfall

Roma Pupils' Identification with School in Slovenia and Serbia: Case Studies

Science.gov (United States)

Macura-Milovanovic, Suncica; Munda, Milanka; Pecek, Mojca

2013-01-01

The research presented in this paper aims to challenge the belief held by some education professionals that Roma pupils do not value education. The research sample included groups of Roma pupils from two countries (Slovenia and Serbia) and from different socio-economic backgrounds. The results suggest that the majority of the pupils are aware of…

From Mathematical Monsters to Generalized Scale Invariance in Geophysics: Highlights of the Multifractal Saga

Science.gov (United States)

Schertzer, D. J.; Tchiguirinskaia, I.; Lovejoy, S.

2013-12-01

Fractals and multifractals are very illustrative of the profound synergies between mathematics and geophysics. The book ';Fractal Geometry of Nature' (Mandelbrot, 1982) brilliantly demonstrated the genericity in geophysics of geometric forms like Cantor set, Peano curve and Koch snowflake, which were once considered as mathematical monsters. However, to tame the geophysical monsters (e.g. extreme weather, floods, earthquakes), it was required to go beyond geometry and a unique fractal dimension. The concept of multifractal was coined in the course of rather theoretical debates on intermittency in hydrodynamic turbulence, sometimes with direct links to atmospheric dynamics. The latter required a generalized notion of scale in order to deal both with scale symmetries and strong anisotropies (e.g. time vs. space, vertical vs. horizontal). It was thus possible to show that the consequences of intermittency are of first order, not just 'corrections' with respect to the classical non-intermittent modeling. This was in fact a radical paradigm shift for geophysics: the extreme variability of geophysical fields over wide ranges of scale, which had long been so often acknowledged and deplored, suddenly became handy. Recent illustrations are the possibility to track down in large date sets the Higgs boson of intermittence, i.e. a first order multifractal phase transition leading to self-organized criticality, and to simulate intermittent vector fields with the help of Lie cascades, based for instance on random Clifford algebra. It is rather significant that this revolution is no longer limited to fundamental and theoretical problems of geophysics, but now touches many applications including environmental management, in particular for urban management and resilience. These applications are particularly stimulating when taken in their full complexity.

Fluctuation dynamics in geoelectrical data: an investigation by using multifractal detrended fluctuation analysis

International Nuclear Information System (INIS)

Telesca, Luciano; Colangelo, Gerardo; Lapenna, Vincenzo; Macchiato, Maria

2004-01-01

We analyzed fluctuations in the time dynamics of nonstationary geoelectrical data, recorded in a seismic area of southern Italy, by means of the multifractal detrended fluctuation analysis (MF-DFA). The multifractal character of the signal depends mostly on the different long-range properties for small and large fluctuations. The time variation of indices, denoting the departure from monofractal behaviour, reveals an enhancement of the multifractality of the signal prior seismic occurrences

A combined QSAR and partial order ranking approach to risk assessment.

Science.gov (United States)

Carlsen, L

2006-04-01

QSAR generated data appear as an attractive alternative to experimental data as foreseen in the proposed new chemicals legislation REACH. A preliminary risk assessment for the aquatic environment can be based on few factors, i.e. the octanol-water partition coefficient (Kow), the vapour pressure (VP) and the potential biodegradability of the compound in combination with the predicted no-effect concentration (PNEC) and the actual tonnage in which the substance is produced. Application of partial order ranking, allowing simultaneous inclusion of several parameters leads to a mutual prioritisation of the investigated substances, the prioritisation possibly being further analysed through the concept of linear extensions and average ranks. The ranking uses endpoint values (log Kow and log VP) derived from strictly linear 'noise-deficient' QSAR models as input parameters. Biodegradation estimates were adopted from the BioWin module of the EPI Suite. The population growth impairment of Tetrahymena pyriformis was used as a surrogate for fish lethality.

Statistical classifiers on multifractal parameters for optical diagnosis of cervical cancer

Science.gov (United States)

Mukhopadhyay, Sabyasachi; Pratiher, Sawon; Kumar, Rajeev; Krishnamoorthy, Vigneshram; Pradhan, Asima; Ghosh, Nirmalya; Panigrahi, Prasanta K.

2017-06-01

An augmented set of multifractal parameters with physical interpretations have been proposed to quantify the varying distribution and shape of the multifractal spectrum. The statistical classifier with accuracy of 84.17% validates the adequacy of multi-feature MFDFA characterization of elastic scattering spectroscopy for optical diagnosis of cancer.

Apparent scale correlations in a random multifractal process

DEFF Research Database (Denmark)

Cleve, Jochen; Schmiegel, Jürgen; Greiner, Martin

2008-01-01

We discuss various properties of a homogeneous random multifractal process, which are related to the issue of scale correlations. By design, the process has no built-in scale correlations. However, when it comes to observables like breakdown coefficients, which are based on a coarse......-graining of the multifractal field, scale correlations do appear. In the log-normal limit of the model process, the conditional distributions and moments of breakdown coefficients reproduce the observations made in fully developed small-scale turbulence. These findings help to understand several puzzling empirical details...

CULTURAL-ECOLOGICAL THEORY AND THE LANGUAGE EDUCATION OF ROMA CHILDREN

Directory of Open Access Journals (Sweden)

Hristo Kyuchukov

2017-12-01

Full Text Available The paper presents results from language testing of 70 Roma children from Bulgaria - pupils of grade 1, studying in one of the biggest Roma settlement’s schools in Sofia, “Fakulteta” district. The children were tested using the Peabody Picture Vocabulary Test. The test measures language comprehension and language production of the children at the beginning and end of the school year. Between the first and second testing, the teaching methodology in instruction for the children was changed - a Roma assistant teacher whose task was to use the mother tongue of the children as a communicative tool was introduced to the classes. The results of the children during the second testing were substantially better and they are discussed in the light of the theory of the American anthropologist J. Ogbu, who developed his cultural-ecological theory (CE in the 1980s. The results of the children are analyzed via dispersion analysis using ANOVA. According to Ogbu’s CE theory, the school success of minority children depends on the attitudes of the society at large and the level of community support. The paper also briefly discusses the reason why the de-segregation of the Roma children and their integration into mainstream schools in Bulgaria has largely proved to be a failure.

Shame and Anxiety Feelings of a Roma Population in Greece.

Science.gov (United States)

Gouva, M; Mentis, M; Kotrotsiou, S; Paralikas, Th; Kotrotsiou, E

2015-12-01

Shame is a crucial issue for Roma. The purpose of the present study was to evaluate the severity of shame and anxiety feelings in a Roma population living in Greece and assess the differentiation of these feelings between Roma men and women. A quota sample of 194 Roma adult men and women living in Southern Greece was retrieved. The Experiences of Shame Scale (ESS), the Other As Shamer Scale (OAS) and the Spielberg's State/Trait Anxiety Inventory (STAI) questionnaires were used. Women scored statistically significantly higher than men on ESS, whereas men scored higher on OAS scale (52.27 ± 16.91 vs 45.42 ± 9.98 and 35.93 ± 16.94 vs 30.87 ± 13.72 respectively). Women scored higher than men in both STAI subscales, however significant differences were observed only in State Anxiety scale (48.83 ± 9.26 vs 43.20 ± 9.81). OAS total score was inversely related to state anxiety, whereas ESS total score was positive related to trait anxiety, all correlations being significant at p Cultural, social and minority issues contribute to feelings of inferiority and anxiety experience.

A Different Guest Worker Story: Roma Guest Workers – a Transnational Minority in Transmigration

Directory of Open Access Journals (Sweden)

Ana Banić-Grubišić

2016-03-01

Full Text Available he paper considers the ambiguity of the term ‘guest worker’, based on the example of economic migrants who belong to the Roma population. Over the last fifty years, members of the Roma minority have migrated to Western European countries for different reasons (economic, political and social reasons, and there is no official data on the precise number of Roma who have migrated abroad, whether permanently or temporarily. It is possible to establish a number of categories of Roma immigrants who reside permanently or temporarily in Western European countries. These are: the so-called “classic guest workers” who, through legal or illegal means went to work abroad in the 60’s and 70’s, and mostly settled permanently in the host countries; Roma refugees from Kosovo and/or asylum seekers who left the country during the wars in the 90’s, and who were returned to Serbia after the signing of the Readmission treaty; and those Roma who represent occasional economic migrants: people who, after Serbia was put on the white Schengen list (the liberalization of the visa policy for citizens of Serbia, spend three months at a time working abroad. Even though these three categories of Roma workers have different reasons for migrating from and returning to Serbia, the majority of the population perceives them as a unified, distinct whole – as guest workers. The paper is the result of fieldwork conducted in South-Eastern Serbia, in the village of Minicevo.

THE APPLICATION OF WAVELET-MULTIFRACTAL ANALYSIS IN PROBLEMS OF METAL STRUCTURE

Directory of Open Access Journals (Sweden)

VOLCHUK V. N.

2015-09-01

Full Text Available Raising of problem. In order to obtain acceptable results of the evaluation of the metal structure developed methodology should include the use of both classical and modern methods of its evaluation and the properties of the produced goods. Thus, to establish the relationship between mechanical properties and structural elements of metal to use multifractal theory. The proposed method is the most appropriate to quantify the majority of real structures, which are integral approximation figures Euclid introduces some uncertainty, and therefore not always acceptable in practical problems of modern materials science. According to the proposed method, each of heterogeneous objects, which are the structures most metals can be characterized by variety of statistical Renyi dimensions. The range of dimensions multifractals interpreted as some of the physical laws, which have a separate statistical properties that make it possible to their financial performance. Application of statistical dimensions of the structural elements for the assessment of qualitative characteristics of metal contributes to their formalization as a function of the fractal dimension. This in turn makes it possible to identify and anticipate the physical and mechanical properties of the metal without producing special mechanical tests. Purpose  obtain information about the possible application of wavelet-multifractal analysis to assess the microstructure of the metal. Conclusion. Using the methods of wavelet multifractal analysis, a statistical evaluation of the structural elements of steel St3ps. An analysis of the characteristics of uniformity, consistency and regularity of the structural elements has shown that most of the change observed in the samples subjected to accelerated cooling water in the temperature range of the intermediate (bainitic conversion 550 – 4500С, less - in samples cooled in the temperature range 650 pearlite transformation  6000С and the smallest

Multifractal characterization of cerebrovascular dynamics in newborn rats

International Nuclear Information System (INIS)

Pavlov, A.N.; Semyachkina-Glushkovskaya, O.V.; Lychagov, V.V.; Abdurashitov, A.S.; Pavlova, O.N.; Sindeeva, O.A.; Sindeev, S.S.

2015-01-01

In this paper we study the cerebrovascular dynamics in newborn rats using the wavelet-based multifractal formalism in order to reveal effective markers of early pathological changes in the macro- and microcirculation at the hidden stage of the development of intracranial hemorrhage (ICH). We demonstrate that the singularity spectrum estimated with the wavelet-transform modulus maxima (WTMM) technique allows clear characterization of a reduced complexity of blood flow dynamics and changes of the correlation properties at the transformation of normal physiological processes into pathological dynamics that are essentially different at the level of large and small blood vessels

A VLSI Implementation of Rank-Order Searching Circuit Employing a Time-Domain Technique

Directory of Open Access Journals (Sweden)

Trong-Tu Bui

2013-01-01

Full Text Available We present a compact and low-power rank-order searching (ROS circuit that can be used for building associative memories and rank-order filters (ROFs by employing time-domain computation and floating-gate MOS techniques. The architecture inherits the accuracy and programmability of digital implementations as well as the compactness and low-power consumption of analog ones. We aim to implement identification function as the first priority objective. Filtering function would be implemented once the location identification function has been carried out. The prototype circuit was designed and fabricated in a 0.18 μm CMOS technology. It consumes only 132.3 μW for an eight-input demonstration case.

Securing a Right to Health: "Integration Villages" and Medical Citizenship of Roma People in France.

Science.gov (United States)

Manson, Daniel

2017-12-01

A national deportation campaign targeting Romanian Roma in France has recently drawn international criticism from human rights organizations and the European Union. In this context, some French municipalities have created villages d'insertion -integration villages-for some of their Roma residents. Proponents of these spaces have declared that they are humanitarian solutions to the existence of Roma slums in the urban peripheries of many French cities. Yet the creation of a "healthy space" for Roma migrants in the city has also legitimated the further eviction and exclusion of people from "unhealthy slums." This article is based on ethnographic research among residents of an integration village and a number of unauthorized encampments in Strasbourg, France. This article analyzes the village d'insertion as a contemporary setting where the uneven medical citizenship of Roma migrants in France is being articulated in relation to wider debates about Roma inclusion in Europe. Ultimately, the village d'insertion is a local manifestation of state power, where the division between those deserving and undeserving of public support is reconfigured through the provision and exclusion of access to rights such as health care and shelter.

A quantitative experimental paradigm to optimize construction of rank order lists in the National Resident Matching Program: the ROSS-MOORE approach.

Science.gov (United States)

Ross, David A; Moore, Edward Z

2013-09-01

As part of the National Resident Matching Program, programs must submit a rank order list of desired applicants. Despite the importance of this process and the numerous manifest limitations with traditional approaches, minimal research has been conducted to examine the accuracy of different ranking strategies. The authors developed the Moore Optimized Ordinal Rank Estimator (MOORE), a novel algorithm for ranking applicants that is based on college sports ranking systems. Because it is not possible to study the Match in vivo, the authors then designed the Recruitment Outcomes Simulation System (ROSS). This program was used to simulate a series of interview seasons and to compare MOORE and traditional approaches under different conditions. The accuracy of traditional ranking and the MOORE approach are equally and adversely affected with higher levels of intrarater variability. However, compared with traditional ranking methods, MOORE produces a more accurate rank order list as interrater variability increases. The present data demonstrate three key findings. First, they provide proof of concept that it is possible to scientifically test the accuracy of different rank methods used in the Match. Second, they show that small amounts of variability can have a significant adverse impact on the accuracy of rank order lists. Finally, they demonstrate that an ordinal approach may lead to a more accurate rank order list in the presence of interviewer bias. The ROSS-MOORE approach offers programs a novel way to optimize the recruitment process and, potentially, to construct a more accurate rank order list.

Multifractal analysis of oceanic chlorophyll maps remotely sensed from space

Directory of Open Access Journals (Sweden)

L. de Montera

2011-03-01

Full Text Available Phytoplankton patchiness has been investigated with multifractal analysis techniques. We analyzed oceanic chlorophyll maps, measured by the SeaWiFS orbiting sensor, which are considered to be good proxies for phytoplankton. The study area is the Senegalo-Mauritanian upwelling region, because it has a low cloud cover and high chlorophyll concentrations. Multifractal properties are observed, from the sub-mesoscale up to the mesoscale, and are found to be consistent with the Corssin-Obukhov scale law of passive scalars. This result indicates that, in this specific region and within this scale range, turbulent mixing would be the dominant effect leading to the observed variability of phytoplankton fields. Finally, it is shown that multifractal patchiness can be responsible for significant biases in the nonlinear source and sink terms involved in biogeochemical numerical models.

One Culture or Multiple Cultures? The Diversity of Roma People in Poland

Directory of Open Access Journals (Sweden)

Joanna Talewicz-Kwiatkowska

2014-12-01

Full Text Available One Culture or Multiple Cultures? The Diversity of Roma People in Poland There are no universal criteria which would be useful to describe the diversity of all of the Roma. Their presence in given country is linked to adaptive processes to majority societies. It is the majority that creates condition and space to which minorities need to adapt somehow. The results of the above-mentioned adaptive processes also vary and depend on an external context. The attitude of given populations towards minorities and the current political and economic situation of given country, where the Roma settled had and still has significant influence on mentioned processes. The way of life of different Romani groups has also a great importance, because sedentary way of life (typical for most European Roma and external influences especially on culture and models of lifestyle also furthered the adaptive processes. The cultural diversity among the Roma is the case not only with the groups living in different countries. It needs to be emphasized that the Roma who have lived in one country for centuries are not a homogenous group in terms of their culture. Previous migration processes and sedentary or nomadic way of life had a great influence on this internal diversity. In Poland with four distinguished Romani groups such diversity occurs between Carpathian Roma (Bergitka Roma, Polish Highlander Roma and traditionally nomadic groups: Polska Roma, Lovara, Kelderari. This article is mainly based on available sources and dissertations on the subject. However it refers to the field research regarding the use of European Union’s funds for the Roma community in Poland, which was conducted by the author in 2010 and 2011.   Kultura jedna czy wieloraka? Zróżnicowanie populacji romskiej w Polsce Nie istnieją uniwersalne kryteria użyteczne w opisie zróżnicowania wszystkich Romów. Ich obecność w danym kraju wiąże się z procesami adaptowania się do społeczeństw wi

Dual-induced multifractality in online viewing activity

Science.gov (United States)

Qin, Yu-Hao; Zhao, Zhi-Dan; Cai, Shi-Min; Gao, Liang; Stanley, H. Eugene

2018-01-01

Although recent studies have found that the long-term correlations relating to the fat-tailed distribution of inter-event times exist in human activity and that these correlations indicate the presence of fractality, the property of fractality and its origin have not been analyzed. We use both detrended fluctuation analysis and multifractal detrended fluctuation analysis to analyze the time series in online viewing activity separating from Movielens and Netflix. We find long-term correlations at both the individual and communal levels and that the extent of correlation at the individual level is determined by the activity level. These long-term correlations also indicate that there is fractality in the pattern of online viewing. We first find a multifractality that results from the combined effect of the fat-tailed distribution of inter-event times (i.e., the times between successive viewing actions of individuals) and the long-term correlations in online viewing activity and verify this finding using three synthesized series. Therefore, it can be concluded that the multifractality in online viewing activity is caused by both the fat-tailed distribution of inter-event times and the long-term correlations and that this enlarges the generic property of human activity to include not just physical space but also cyberspace.

Work-integrated learning and health literacy as catalysts for Roma empowerment and social inclusion

DEFF Research Database (Denmark)

Eklund Karlsson, Leena; Ringsberg, Karin C; Crondahl, Kristine

2018-01-01

Roma people all over the world have often been subject to prejudice, stigma, discrimination and oppression. Many Roma have little or no education, which in combination with other factors often leads to unemployment and marginalization. Based on a case study in Sweden, this paper proposes an appro......Roma people all over the world have often been subject to prejudice, stigma, discrimination and oppression. Many Roma have little or no education, which in combination with other factors often leads to unemployment and marginalization. Based on a case study in Sweden, this paper proposes...... participants. The findings indicate that work-integrated learning may be a worthwhile approach for increasing the individual empowerment and self-led social inclusion of vulnerable people. However, the obstacles of structural discriminatory nature hindered the project to reach its full potential in its...

Multifractals in Western Major STOCK Markets Historical Volatilities in Times of Financial Crisis

Science.gov (United States)

Lahmiri, Salim

In this paper, the generalized Hurst exponent is used to investigate multifractal properties of historical volatility (CHV) in stock market price and return series before, during and after 2008 financial crisis. Empirical results from NASDAQ, S&P500, TSE, CAC40, DAX, and FTSE stock market data show that there is strong evidence of multifractal patterns in HV of both price and return series. In addition, financial crisis deeply affected the behavior and degree of multifractality in volatility of Western financial markets at price and return levels.

Price-volume multifractal analysis and its application in Chinese stock markets

Science.gov (United States)

Yuan, Ying; Zhuang, Xin-tian; Liu, Zhi-ying

2012-06-01

An empirical research on Chinese stock markets is conducted using statistical tools. First, the multifractality of stock price return series, ri(ri=ln(Pt+1)-ln(Pt)) and trading volume variation series, vi(vi=ln(Vt+1)-ln(Vt)) is confirmed using multifractal detrended fluctuation analysis. Furthermore, a multifractal detrended cross-correlation analysis between stock price return and trading volume variation in Chinese stock markets is also conducted. It is shown that the cross relationship between them is also found to be multifractal. Second, the cross-correlation between stock price Pi and trading volume Vi is empirically studied using cross-correlation function and detrended cross-correlation analysis. It is found that both Shanghai stock market and Shenzhen stock market show pronounced long-range cross-correlations between stock price and trading volume. Third, a composite index R based on price and trading volume is introduced. Compared with stock price return series ri and trading volume variation series vi, R variation series not only remain the characteristics of original series but also demonstrate the relative correlation between stock price and trading volume. Finally, we analyze the multifractal characteristics of R variation series before and after three financial events in China (namely, Price Limits, Reform of Non-tradable Shares and financial crisis in 2008) in the whole period of sample to study the changes of stock market fluctuation and financial risk. It is found that the empirical results verified the validity of R.

MULTIFRACTAL STRUCTURES DETECTED BY VOYAGER 1 AT THE HELIOSPHERIC BOUNDARIES

International Nuclear Information System (INIS)

Macek, W. M.; Wawrzaszek, A.; Burlaga, L. F.

2014-01-01

To better understand the dynamics of turbulent systems, we have proposed a phenomenological model based on a generalized Cantor set with two rescaling and one weight parameters. In this Letter, using recent Voyager 1 magnetic field data, we extend our two-scale multifractal analysis further in the heliosheath beyond the heliospheric termination shock, and even now near the heliopause, when entering the interstellar medium for the first time in human history. We have identified the scaling inertial region for magnetized heliospheric plasma between the termination shock and the heliopause. We also show that the degree of multifractality decreases with the heliocentric distance and is still modulated by the phases of the solar cycle in the entire heliosphere including the heliosheath. Moreover, we observe the change of scaling toward a nonintermittent (nonmultifractal) behavior in the nearby interstellar medium, just beyond the heliopause. We argue that this loss of multifractal behavior could be a signature of the expected crossing of the heliopause by Voyager 2 in the near future. The results obtained demonstrate that our phenomenological multifractal model exhibits some properties of intermittent turbulence in the solar system plasmas, and we hope that it could shed light on universal characteristics of turbulence

MULTIFRACTAL STRUCTURES DETECTED BY VOYAGER 1 AT THE HELIOSPHERIC BOUNDARIES

Energy Technology Data Exchange (ETDEWEB)

Macek, W. M. [Faculty of Mathematics and Natural Sciences, Cardinal Stefan Wyszyński University, Wóycickiego 1/3, 01-938 Warsaw (Poland); Wawrzaszek, A. [Space Research Centre, Polish Academy of Sciences, Bartycka 18 A, 00-716 Warszawa (Poland); Burlaga, L. F., E-mail: macek@cbk.waw.pl, E-mail: anna.wawrzaszek@cbk.waw.pl, E-mail: lburlagahsp@verizon.net [NASA Goddard Space Flight Center, Code 673, Greenbelt, MD 20771 (United States)

2014-10-01

To better understand the dynamics of turbulent systems, we have proposed a phenomenological model based on a generalized Cantor set with two rescaling and one weight parameters. In this Letter, using recent Voyager 1 magnetic field data, we extend our two-scale multifractal analysis further in the heliosheath beyond the heliospheric termination shock, and even now near the heliopause, when entering the interstellar medium for the first time in human history. We have identified the scaling inertial region for magnetized heliospheric plasma between the termination shock and the heliopause. We also show that the degree of multifractality decreases with the heliocentric distance and is still modulated by the phases of the solar cycle in the entire heliosphere including the heliosheath. Moreover, we observe the change of scaling toward a nonintermittent (nonmultifractal) behavior in the nearby interstellar medium, just beyond the heliopause. We argue that this loss of multifractal behavior could be a signature of the expected crossing of the heliopause by Voyager 2 in the near future. The results obtained demonstrate that our phenomenological multifractal model exhibits some properties of intermittent turbulence in the solar system plasmas, and we hope that it could shed light on universal characteristics of turbulence.

International Policy and Roma Education in Europe: Essential Inputs or Centralized Distractions?

Science.gov (United States)

Ram, Melanie H.

2015-01-01

This article examines the case of Roma inclusion in education as a study of the ways in which international policy can and cannot bring change at the local level. I first reflect on the numerous international organizations and initiatives to improve the educational outcomes of Roma, and to reduce segregation and other non-inclusionary practices.…

Multifractal spectrum analysis of nonlinear dynamical mechanisms in China’s agricultural futures markets

Science.gov (United States)

Chen, Shu-Peng; He, Ling-Yun

2010-04-01

Based on Partition Function and Multifractal Spectrum Analysis, we investigated the nonlinear dynamical mechanisms in China’s agricultural futures markets, namely, Dalian Commodity Exchange (DCE for short) and Zhengzhou Commodity Exchange (ZCE for short), where nearly all agricultural futures contracts are traded in the two markets. Firstly, we found nontrivial multifractal spectra, which are the empirical evidence of the existence of multifractal features, in 4 representative futures markets in China, that is, Hard Winter wheat (HW for short) and Strong Gluten wheat (SG for short) futures markets from ZCE and Soy Meal (SM for short) futures and Soy Bean No.1 (SB for short) futures markets from DCE. Secondly, by shuffling the original time series, we destroyed the underlying nonlinear temporal correlation; thus, we identified that long-range correlation mechanism constitutes major contributions in the formation in the multifractals of the markets. Thirdly, by tracking the evolution of left- and right-half spectra, we found that there exist critical points, between which there are different behaviors, in the left-half spectra for large price fluctuations; but for the right-hand spectra for small price fluctuations, the width of those increases slowly as the delay t increases in the long run. Finally, the dynamics of large fluctuations is significantly different from that of the small ones, which implies that there exist different underlying mechanisms in the formation of multifractality in the markets. Our main contributions focus on that we not only provided empirical evidence of the existence of multifractal features in China agricultural commodity futures markets; but also we pioneered in investigating the sources of the multifractality in China’s agricultural futures markets in current literature; furthermore, we investigated the nonlinear dynamical mechanisms based on spectrum analysis, which offers us insights into the underlying dynamical mechanisms in

Exploring the Barriers: A Qualitative Study about the Experiences of Mid-SES Roma Navigating the Spanish Healthcare System.

Science.gov (United States)

Aiello, Emilia; Flecha, Ainhoa; Serradell, Olga

2018-02-22

Whereas the topic of the 'cultural sensitivity' of healthcare systems has been addressed extensively in the US and the UK, literature on the subject in most European countries, specifically looking at the situation of Roma, is still scarce. Drawing on qualitative research conducted mainly in the city of Barcelona under the communicative approach with Roma subjects who have stable socioeconomic positions and higher cultural capitals (end-users, professionals of the healthcare system, and key informants of a regional policy oriented to the improvement of Roma living conditions), the present study aims to fill this gap. We explore the barriers that the Roma face in accessing the healthcare system, reflecting on how these barriers are accentuated by the existing anti-Roma prejudices and institutional arrangements that do not account for minority cultures. Our results point out a series of obstacles at two levels, in the interaction with healthcare professionals, and in relation to existing institutional arrangements, which prevent Roma families from having equal access to the healthcare system. Education stands up as a mechanism to contest anti-Roma sentiments among healthcare professionals.

Roma Hip Hop as a Multiculturalist Soundtrack. R-Point: The Pedagogy of a Policy

Directory of Open Access Journals (Sweden)

Ana Banić-Grubišić

2016-02-01

Full Text Available This paper examines the phenomenon of Roma hip hop in Serbia, its origins and popularization through music workshops for Roma children organized by the non-governmental organization R-Point. The paper analyzes a supposedly liberatory cultural practice, and argues that its designing „from above“, through non-governmental agencies' projects whose declarative aim is to help the Roma, actually petrifies their identity, reducing their entire cultural output to certain elements attractive to the dominant culture and traditionally recognized as „Roma“.

Multifractality and quantum diffusion from self-consistent theory of localization

Energy Technology Data Exchange (ETDEWEB)

Suslov, I. M., E-mail: suslov@kapitza.ras.ru [Kapitza Institute for Physical Problems (Russian Federation)

2015-11-15

Multifractal properties of wave functions in a disordered system can be derived from self-consistent theory of localization by Vollhardt and Wölfle. A diagrammatic interpretation of results allows to obtain all scaling relations used in numerical experiments. The arguments are given that the one-loop Wegner result for a space dimension d = 2 + ϵ is exact, so the multifractal spectrum is strictly parabolical. The σ-models are shown to be deficient at the four-loop level and the possible reasons of that are discussed. The extremely slow convergence to the thermodynamic limit is demonstrated. The open question on the relation between multifractality and a spatial dispersion of the diffusion coefficient D(ω, q) is resolved in the compromise manner due to ambiguity of the D(ω, q) definition. Comparison is made with the extensive numerical material.

Involving Roma parents: analysing the good practice of a primary school in Ghent

NARCIS (Netherlands)

Wauters, J.; Van Mol, C.; Clycq, N.; Michielsen, J.; Timmerman, C.

2017-01-01

Recently, societal and academic attention toward the topic of Roma integration has been increasing. With this article we aim to make a contribution to the domain of educational research. We explore strategies that schools can adopt to improve the involvement of Roma parents. Using a theory-based

Risk factors associated with the practice of child marriage among Roma girls in Serbia.

Science.gov (United States)

Hotchkiss, David R; Godha, Deepali; Gage, Anastasia J; Cappa, Claudia

2016-02-01

Relatively little research on the issue of child marriage has been conducted in European countries where the overall prevalence of child marriage is relatively low, but relatively high among marginalized ethnic sub-groups. The purpose of this study is to assess the risk factors associated with the practice of child marriage among females living in Roma settlements in Serbia and among the general population and to explore the inter-relationship between child marriage and school enrollment decisions. The study is based on data from a nationally representative household survey in Serbia conducted in 2010 - and a separate survey of households living in Roma settlements in the same year. For each survey, we estimated a bivariate probit model of risk factors associated with being currently married and currently enrolled in school based on girls 15 to 17 years of age in the nationally representative and Roma settlements samples. The practice of child marriage among the Roma was found to be most common among girls who lived in poorer households, who had less education, and who lived in rural locations. The results of the bivariate probit analysis suggest that, among girls in the general population, decisions about child marriage school attendance are inter-dependent in that common unobserved factors were found to influence both decisions. However, among girls living in Roma settlements, there is only weak evidence of simultaneous decision making. The study finds evidence of the interdependence between marriage and school enrollment decisions among the general population and, to a lesser extent, among the Roma. Further research is needed on child marriage among the Roma and other marginalized sub-groups in Europe, and should be based on panel data, combined with qualitative data, to assess the role of community-level factors and the characteristics of households where girls grow up on child marriage and education decisions.

A Multifractal Detrended Fluctuation Analysis of the Ising Financial Markets Model with Small World Topology

International Nuclear Information System (INIS)

Zhang Ang-Hui; Li Xiao-Wen; Su Gui-Feng; Zhang Yi

2015-01-01

We present a multifractal detrended fluctuation analysis (MFDFA) of the time series of return generated by our recently-proposed Ising financial market model with underlying small world topology. The result of the MFDFA shows that there exists obvious multifractal scaling behavior in produced time series. We compare the MFDFA results for original time series with those for shuffled series, and find that its multifractal nature is due to two factors: broadness of probability density function of the series and different correlations in small- and large-scale fluctuations. This may provide new insight to the problem of the origin of multifractality in financial time series. (paper)

Clustering Multiple Sclerosis Subgroups with Multifractal Methods and Self-Organizing Map Algorithm

Science.gov (United States)

Karaca, Yeliz; Cattani, Carlo

Magnetic resonance imaging (MRI) is the most sensitive method to detect chronic nervous system diseases such as multiple sclerosis (MS). In this paper, Brownian motion Hölder regularity functions (polynomial, periodic (sine), exponential) for 2D image, such as multifractal methods were applied to MR brain images, aiming to easily identify distressed regions, in MS patients. With these regions, we have proposed an MS classification based on the multifractal method by using the Self-Organizing Map (SOM) algorithm. Thus, we obtained a cluster analysis by identifying pixels from distressed regions in MR images through multifractal methods and by diagnosing subgroups of MS patients through artificial neural networks.

The foreign exchange market: return distributions, multifractality, anomalous multifractality and the Epps effect

Science.gov (United States)

Drożdż, Stanisław; Kwapień, Jarosław; Oświȩcimka, Paweł; Rak, Rafał

2010-10-01

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 of the pairs considered are well described by the non-extensive statistics in terms of q-Gaussians. There exist some small quantitative variations in the non-extensivity q-parameter values for different exchange rates (which depend also on the time scales studied), 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 of the exchange rates, with a varying degree of symmetry of the singularity spectrum f(α), 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 of these residual returns reveal such anomalous properties as negative singularity exponents and even negative singularity spectra. Such anomalous multifractal measures have so far been considered in the literature in connection with diffusion-limited aggregation and with turbulence. Studying the cross-correlations among different exchange rates, we found that market inefficiency on short time scales leads to the occurrence of the Epps effect on much longer time scales, but comparable to the ones for the stock market. Although the currency market is much more liquid than the stock markets and has a much greater transaction frequency, the building up of correlations takes up to several hours—a duration that does not differ much from what is observed in the stock markets. This may suggest

A Macroscopic Multifractal Analysis of Parabolic Stochastic PDEs

Science.gov (United States)

Khoshnevisan, Davar; Kim, Kunwoo; Xiao, Yimin

2018-05-01

It is generally argued that the solution to a stochastic PDE with multiplicative noise—such as \\dot{u}= 1/2 u''+uξ, where {ξ} denotes space-time white noise—routinely produces exceptionally-large peaks that are "macroscopically multifractal." See, for example, Gibbon and Doering (Arch Ration Mech Anal 177:115-150, 2005), Gibbon and Titi (Proc R Soc A 461:3089-3097, 2005), and Zimmermann et al. (Phys Rev Lett 85(17):3612-3615, 2000). A few years ago, we proved that the spatial peaks of the solution to the mentioned stochastic PDE indeed form a random multifractal in the macroscopic sense of Barlow and Taylor (J Phys A 22(13):2621-2626, 1989; Proc Lond Math Soc (3) 64:125-152, 1992). The main result of the present paper is a proof of a rigorous formulation of the assertion that the spatio-temporal peaks of the solution form infinitely-many different multifractals on infinitely-many different scales, which we sometimes refer to as "stretch factors." A simpler, though still complex, such structure is shown to also exist for the constant-coefficient version of the said stochastic PDE.

A Macroscopic Multifractal Analysis of Parabolic Stochastic PDEs

Science.gov (United States)

Khoshnevisan, Davar; Kim, Kunwoo; Xiao, Yimin

2018-04-01

It is generally argued that the solution to a stochastic PDE with multiplicative noise—such as \\dot{u}= 1/2 u''+uξ, where {ξ} denotes space-time white noise—routinely produces exceptionally-large peaks that are "macroscopically multifractal." See, for example, Gibbon and Doering (Arch Ration Mech Anal 177:115-150, 2005), Gibbon and Titi (Proc R Soc A 461:3089-3097, 2005), and Zimmermann et al. (Phys Rev Lett 85(17):3612-3615, 2000). A few years ago, we proved that the spatial peaks of the solution to the mentioned stochastic PDE indeed form a random multifractal in the macroscopic sense of Barlow and Taylor (J Phys A 22(13):2621-2626, 1989; Proc Lond Math Soc (3) 64:125-152, 1992). The main result of the present paper is a proof of a rigorous formulation of the assertion that the spatio-temporal peaks of the solution form infinitely-many different multifractals on infinitely-many different scales, which we sometimes refer to as "stretch factors." A simpler, though still complex, such structure is shown to also exist for the constant-coefficient version of the said stochastic PDE.

Analyzing the LiF thin films deposited at different substrate temperatures using multifractal technique

Energy Technology Data Exchange (ETDEWEB)

Yadav, R.P. [Department of Physics, University of Allahabad, Allahabad, UP 211002 (India); Dwivedi, S., E-mail: suneetdwivedi@gmail.com [K Banerjee Centre of Atmospheric and Ocean Studies, University of Allahabad, Allahabad, UP 211002 (India); Mittal, A.K. [Department of Physics, University of Allahabad, Allahabad, UP 211002 (India); K Banerjee Centre of Atmospheric and Ocean Studies, University of Allahabad, Allahabad, UP 211002 (India); Kumar, Manvendra [Nanotechnology Application Centre, University of Allahabad, Allahabad, UP 211002 (India); Pandey, A.C. [K Banerjee Centre of Atmospheric and Ocean Studies, University of Allahabad, Allahabad, UP 211002 (India); Nanotechnology Application Centre, University of Allahabad, Allahabad, UP 211002 (India)

2014-07-01

The Atomic Force Microscopy technique is used to characterize the surface morphology of LiF thin films deposited at substrate temperatures 77 K, 300 K and 500 K, respectively. It is found that the surface roughness of thin film increases with substrate temperature. The multifractal nature of the LiF thin film at each substrate temperature is investigated using the backward two-dimensional multifractal detrended moving average analysis. The strength of multifractility and the non-uniformity of the height probabilities of the thin films increase as the substrate temperature increases. Both the width of the multifractal spectrum and the difference of fractal dimensions of the thin films increase sharply as the temperature reaches 500 K, indicating that the multifractility of the thin films becomes more pronounced at the higher substrate temperatures with greater cluster size. - Highlights: • Analyzing LiF thin films using multifractal detrended moving average technique • Surface roughness of LiF thin film increases with substrate temperature. • LiF thin films at each substrate temperature exhibit multifractality. • Multifractility becomes more pronounced at the higher substrate temperatures.

Multifractal analysis of a GCM climate

Science.gov (United States)

Carl, P.

2003-04-01

Multifractal analysis using the Wavelet Transform Modulus Maxima (WTMM) approach is being applied to the climate of a Mintz--Arakawa type, coarse resolution, two--layer AGCM. The model shows a backwards running period multiplication scenario throughout the northern summer, subsequent to a 'hard', subcritical Hopf bifurcation late in spring. This 'route out of chaos' (seen in cross sections of a toroidal phase space structure) is born in the planetary monsoon system which inflates the seasonal 'cycle' into these higher order structures and is blamed for the pronounced intraseasonal--to--centennial model climate variability. Previous analyses of the latter using advanced modal decompositions showed regularity based patterns in the time--frequency plane which are qualitatively similar to those obtained from the real world. The closer look here at the singularity structures, as a fundamental diagnostic supplement, aims at both more complete understanding (and quantification) of the model's qualitative dynamics and search for further tools of model intercomparison and verification in this respect. Analysing wavelet is the 10th derivative of the Gaussian which might suffice to suppress regular patterns in the data. Intraseasonal attractors, studied in time series of model precipitation over Central India, show shifting and braodening singularity spectra towards both more violent extreme events (premonsoon--monsoon transition) and weaker events (late summer to postmonsoon transition). Hints at a fractal basin boundary are found close to transition from period--2 to period--1 in the monsoon activity cycle. Interannual analyses are provided for runs with varied solar constants. To address the (in--)stationarity issue, first results are presented with a windowed multifractal analysis of longer--term runs ("singularity spectrogram").

Multifractality in Cardiac Dynamics

Science.gov (United States)

Ivanov, Plamen Ch.; Rosenblum, Misha; Stanley, H. Eugene; Havlin, Shlomo; Goldberger, Ary

1997-03-01

Wavelet decomposition is used to analyze the fractal scaling properties of heart beat time series. The singularity spectrum D(h) of the variations in the beat-to-beat intervals is obtained from the wavelet transform modulus maxima which contain information on the hierarchical distribution of the singularities in the signal. Multifractal behavior is observed for healthy cardiac dynamics while pathologies are associated with loss of support in the singularity spectrum.

State of Impunity: Human Rights Abuse of Roma in Romania. Country Reports Series.

Science.gov (United States)

Cahn, Claude; Petrova, Dimitrina

This report documents civil violations and discriminatory actions against Roma in Romania, contending that, due to the Romanian government's inadequate efforts to bring perpetrators of anti-Romani crimes to justice and to eradicate discrimination against Roma, a climate of impunity surrounding anti-Romani actions has taken deep root. Chapter 1…

The Power of Discourse: Reflections on the Obstacles to Social Inclusion of Roma in Serbia

Directory of Open Access Journals (Sweden)

Jelena Vidojević

2015-09-01

Full Text Available The authors explore the discourses around the exclusion of the Roma in Serbia in two dimensions: social welfare sector and media reports. The paper is structured around the presentation of dimensions contributing to multiple deprivation of Roma in society (from education to labor market participation, social welfare and health care, as well as housing; a review of public policies directed toward the improvement of their position; and analysis of the discourses on Roma within the contexts of the social welfare sector and media reporting. A review of related literature and public policy documents was followed by a qualitative analysis of media reports as well as a review of the secondary sources regarding media discourses on the Roma. This was followed by evidence gathered from semi-structured interviews and discussions with stakeholders in the social welfare sector. The main conclusions of the paper point to the mutual reinforcement of the discourses on the Roma in the social welfare sector and media reports, with their subsequent mutual contribution to social exclusion.

Poverty and Ethnicity: A Cross-Country Study of Roma Poverty in Central Europe. World Bank Technical Paper.

Science.gov (United States)

Revenga, Ana; Ringold, Dena; Tracy, William Martin

Roma, or "gypsies," are the main poverty risk group in many countries of central and eastern Europe. Living standards for the Roma have deteriorated more severely during the region's transition to a market economy than they have for other population groups, and Roma have been poorly positioned to take advantage of emerging economic and…

Estimation of the global regularity of a multifractional Brownian motion

DEFF Research Database (Denmark)

Lebovits, Joachim; Podolskij, Mark

This paper presents a new estimator of the global regularity index of a multifractional Brownian motion. Our estimation method is based upon a ratio statistic, which compares the realized global quadratic variation of a multifractional Brownian motion at two different frequencies. We show that a ...... that a logarithmic transformation of this statistic converges in probability to the minimum of the Hurst functional parameter, which is, under weak assumptions, identical to the global regularity index of the path....

Does the population living in Roma settlements differ in physical activity, smoking and alcohol consumption from the majority population in Slovakia?

Science.gov (United States)

Babinská, Ingrid; Gecková, Andrea Madarasová; Jarcuska, Peter; Pella, Daniel; Mareková, Mária; Stefková, Gabriela; Veselská, Zuzana Dankulincová

2014-03-01

Several studies have revealed a high prevalence of risk factors associated with unhealthy lifestyle among individuals with lower socioeconomic status. In Slovakia, one of the most socially and health-disadvantaged groups is the Roma minority. The aim of this study is to explore differences in physical activity, smoking and alcohol consumption between the population living in Roma settlements and the majority population in Slovakia. Data from the cross-sectional epidemiological HepaMeta study conducted in Slovakia in 2011 were used. The sample consisted of 452 Roma (mean age = 34.7; 35.2% men) and 403 non-Roma (mean age = 33.5; 45.9% men) respondents. The differences in health-related behaviour between the population living in Roma settlements and the majority population were analysed using logistic models separately for males and females. These data show a clear difference between the population living in Roma settlements and the majority population with regard to leisure-time physical activity (only in women) and smoking, although not alcohol consumption. The prevalence of leisure-time physical activities such as walking or some other type of sport was significantly lower among Roma women than among non-Roma women. Men and women living in Roma settlements are more likely to smoke on a daily basis and they are heavier smokers in comparison with the majority population. HepaMeta study did not find differences in alcohol consumption between the Roma and non-Roma men. However, Roma women reported less frequent recent drinking and binge-drinking of 6 or more doses of alcohol on a single occasion. The higher prevalence of unhealthy lifestyle activities among Roma seem to contribute to these inequalities in cardiovascular diseases morbidity and mortality in comparison with the majority population.

Santo Agostinho e o De excidio urbis Romae sermo

OpenAIRE

Urbano, Carlota

2006-01-01

Na sequência da queda de Roma em 410, Santo Agostinho afirma no sermão que aqui tomamos que Roma não foi destruída. Não faltaram da parte da população pagã as acusações ao cristianismo. Os próprios cristãos estariam confundidos ao assistir à humilhação da cidade que guardava os túmulos dos apóstolos Pedro e Paulo. Santo Agostinho não tarda em responder a estas recriminações e perplexidades, primeiro em textos relativamente breves como os Sermões, para além de algumas referências em cartas, e ...

Fractals and multifractals in physics

International Nuclear Information System (INIS)

Arcangelis, L. de.

1987-01-01

We present a general introduction to the world of fractals. The attention is mainly devoted to stress how fractals do indeed appear in the real world and to find quantitative methods for characterizing their properties. The idea of multifractality is also introduced and it is presented in more details within the framework of the percolation problem

Multifractal resilience and viability

Science.gov (United States)

Tchiguirinskaia, I.; Schertzer, D. J. M.

2017-12-01

The term resilience has become extremely fashionable and there had been many attempts to provide operational definition and in fact metrics going beyond a set of more or less ad-hoc indicators. The viability theory (Aubin and Saint-Pierre, 2011) have been used to give a rather precise mathematical definition of resilience (Deffuant and Gilbert, 2011). However, it does not grasp the multiscale nature of resilience that is rather fundamental as particularly stressed by Folke et al (2010). In this communication, we first recall a preliminary attempt (Tchiguirinskaia et al., 2014) to define multifractal resilience with the help of the maximal probable singularity. Then we extend this multifractal approach to the capture basin of the viability, therefore the resilient basin. Aubin, J P, A. Bayen, and P Saint-Pierre (2011). Viability Theory. New Directions. Springer, Berlin,. Deffuant, G. and Gilbert, N. (eds) (2011) Viability and Resilience of Complex Systems. Springer Berlin.Folke, C., S R Carpenter, B Walker, M Sheffer, T Chapin, and J Rockstroem (2010). Resilience thinking: integrating re- silience, adaptability and transformability. Ecology and So- ciety, 14(4):20, Tchiguirinskaia,I., D. Schertzer, , A. Giangola-Murzyn and T. C. Hoang (2014). Multiscale resilience metrics to assess flood. Proceedings of ICCSA 2014, Normandie University, Le Havre, France -.

Risk factors for childhood malnutrition in Roma settlements in Serbia.

Science.gov (United States)

Janevic, Teresa; Petrovic, Oliver; Bjelic, Ivana; Kubera, Amber

2010-08-22

Children living in Roma settlements in Central and Eastern Europe face extreme levels of social exclusion and poverty, but their health status has not been well studied. The objective of this study was to elucidate risk factors for malnutrition in children in Roma settlements in Serbia. Anthropometric and sociodemographic measures were obtained for 1192 Roma children under five living in Roma settlements from the 2005 Serbia Multiple Indicator Cluster Survey. Multiple logistic regression was used to relate family and child characteristics to the odds of stunting, wasting, and underweight. The prevalence of stunting, wasting, and underweight was 20.1%, 4.3%, and 8.0%, respectively. Nearly all of the children studied fell into the lowest quintile of wealth for the overall population of Serbia. Children in the lowest quintile of wealth were four times more likely to be stunted compared to those in the highest quintile, followed by those in the second lowest quintile (AOR = 2.1) and lastly by those in the middle quintile (AOR = 1.6). Children who were ever left in the care of an older child were almost twice as likely to stunted as those were not. Children living in urban settlements showed a clear disadvantage with close to three times the likelihood of being wasted compared to those living in rural areas. There was a suggestion that maternal, but not paternal, education was associated with stunting, and maternal literacy was significantly associated with wasting. Whether children were ever breastfed, immunized or had diarrhoeal episodes in the past two weeks did not show strong correlations to children malnutrition status in this Roma population. There exists a gradient relationship between household wealth and stunting even within impoverished settlements, indicating that among poor and marginalized populations socioeconomic inequities in child health should be addressed. Other areas on which to focus future research and public health intervention include maternal

Risk factors for childhood malnutrition in Roma settlements in Serbia

Directory of Open Access Journals (Sweden)

Janevic Teresa

2010-08-01

Full Text Available Abstract Background Children living in Roma settlements in Central and Eastern Europe face extreme levels of social exclusion and poverty, but their health status has not been well studied. The objective of this study was to elucidate risk factors for malnutrition in children in Roma settlements in Serbia. Methods Anthropometric and sociodemographic measures were obtained for 1192 Roma children under five living in Roma settlements from the 2005 Serbia Multiple Indicator Cluster Survey. Multiple logistic regression was used to relate family and child characteristics to the odds of stunting, wasting, and underweight. Results The prevalence of stunting, wasting, and underweight was 20.1%, 4.3%, and 8.0%, respectively. Nearly all of the children studied fell into the lowest quintile of wealth for the overall population of Serbia. Children in the lowest quintile of wealth were four times more likely to be stunted compared to those in the highest quintile, followed by those in the second lowest quintile (AOR = 2.1 and lastly by those in the middle quintile (AOR = 1.6. Children who were ever left in the care of an older child were almost twice as likely to stunted as those were not. Children living in urban settlements showed a clear disadvantage with close to three times the likelihood of being wasted compared to those living in rural areas. There was a suggestion that maternal, but not paternal, education was associated with stunting, and maternal literacy was significantly associated with wasting. Whether children were ever breastfed, immunized or had diarrhoeal episodes in the past two weeks did not show strong correlations to children malnutrition status in this Roma population. Conclusions There exists a gradient relationship between household wealth and stunting even within impoverished settlements, indicating that among poor and marginalized populations socioeconomic inequities in child health should be addressed. Other areas on which to focus

Do eating habits of the population living in Roma settlements differ from those of the majority population in Slovakia?

Science.gov (United States)

Hijová, Emília; Gecková, Andrea Madarasová; Babinská, Ingrid

2014-03-01

Living in Roma settlements is associated with worse health in comparison with the majority population; this might be partially explained by socioeconomic disadvantages as well as cultural differences, including lifestyle. Eating habits represent an important part of lifestyle closely related to primary causes of morbidity and mortality, such as cardiovascular diseases, metabolic diseases or cancers. The eating habits of the population living in Roma settlements in comparison with those of the majority population were explored using the cross-sectional epidemiological HepaMeta study conducted in 2011. A representative sample of Roma (n = 452, mean age = 34.7; 35.2% men) and non-Roma (n = 403, mean age = 33.5; 45.9% men) aged 18-55 years living in the Kosice region were asked about breakfasting and recent consumption of fruits, vegetables, dairy products, meat products, meat, farinaceous dishes, and soft drinks. A logistic regression model was used separately for male and female participants. The population living in Roma settlements reported the recent consumption of fruit, vegetables and dairy products significantly less frequently in comparison with the majority population. Moreover, Roma females, in comparison with non-Roma females, reported significantly more frequently the consumption of meat and soft drinks. No differences were found between Roma and non-Roma in the consumption of meat products and farinaceous dishes. The population living in Roma settlements reported more frequently unhealthy eating habits in comparison with the majority population; this might contribute to worse health status of this population. The differences might be attributed to cultural differences between ethnic as well as socioeconomic groups, reduced availability of certain food items due to segregation or poverty and lower health literacy.

Genetic structure and admixture between Bayash Roma from northwestern Croatia and general Croatian population: evidence from Bayesian clustering analysis.

Science.gov (United States)

Novokmet, Natalija; Galov, Ana; Marjanović, Damir; Škaro, Vedrana; Projić, Petar; Lauc, Gordan; Primorac, Dragan; Rudan, Pavao

2015-01-01

The European Roma represent a transnational mosaic of minority population groups with different migration histories and contrasting experiences in their interactions with majority populations across the European continent. Although historical genetic contributions of European lineages to the Roma pool were investigated before, the extent of contemporary genetic admixture between Bayash Roma and non-Romani majority population remains elusive. The aim of this study was to assess the genetic structure of the Bayash Roma population from northwestern Croatia and the general Croatian population and to investigate the extent of admixture between them. A set of genetic data from two original studies (100 Bayash Roma from northwestern Croatia and 195 individuals from the general Croatian population) was analyzed by Bayesian clustering implemented in STRUCTURE software. By re-analyzing published data we intended to focus for the first time on genetic differentiation and structure and in doing so we clearly pointed to the importance of considering social phenomena in understanding genetic structuring. Our results demonstrated that two population clusters best explain the genetic structure, which is consistent with social exclusion of Roma and the demographic history of Bayash Roma who have settled in NW Croatia only about 150 years ago and mostly applied rules of endogamy. The presence of admixture was revealed, while the percentage of non-Croatian individuals in general Croatian population was approximately twofold higher than the percentage of non-Romani individuals in Roma population corroborating the presence of ethnomimicry in Roma.

THE METHODOLOGY OF THE ANALYSIS OF CASE STUDY THROUGH THE INTEGRATION OF THE ROMA MINORITY INTO THE SOCIAL SYSTEM

Directory of Open Access Journals (Sweden)

Jelena Maksimović

2017-06-01

Full Text Available The Roma are an ethnic group that is spread throughout the world. Although there are poor ethnographic and historical notes about the origin of Roma on the basis of a study of legends and oral traditions, researchers who are engaged in Roma studies, often confirm that they originate from India. Their culture, habits, customs were mostly transmitted through the living word, from generation to generation. This research analyzed case studies of integration of the Roma minority in the social system. Special emphasis in research is aimed at analyzing stereotypes that arise from cultural patterns of Roma, given the fact that for them there are many different prejudices, while on the other hand, there is no access with critical analysis and does not indicate their specialty, which has its downside exactly in culture and patterns of behavior. The study analyzed how the traditional culture is important in the lives of Roma and how the social system treats this ethnic minority. Being a Rom in its original sense means to be human and to be equal with everyone, but paradoxically it is expected that non-Roma nation sets free of stereotypes and prejudices and to contribute to the integration and acceptance of Roma in our social system.

Multifractal structure of multiparticle production in the branching models

International Nuclear Information System (INIS)

Chiu, C.B.; Hwa, R.C.

1990-01-01

A procedure is described for the multifractal analysis of data on multiparticle production obtained at high energy either in experiment or in Monte Carlo simulation. It is shown how the spectrum f(α) of the rapidity-density index α can be determined from the multiplicity fluctuation of the rapidity distribution, as the resolution is changed. The branching model is used to illustrate the procedure. It is found that the φ 3 model has a narrower f(α) than the gluon model, suggesting that multifractality is a useful arena for confrontation between theory and experiment. 13 refs., 2 figs

Multifractal analysis of vertical profiles of soil penetration resistance at the field scale

Directory of Open Access Journals (Sweden)

G. M. Siqueira

2013-07-01

Full Text Available Soil penetration resistance (PR is widely used as an indirect indicator of soil strength. Soil PR is linked to basic soil properties and correlated to root growth and plant production, and as such it is extensively used as a practical tool for assessing soil compaction and to evaluate the effects of soil management. This study investigates how results from multifractal analysis can quantify key elements of depth-dependent soil PR profiles and how this information can be used at the field scale. We analysed multifractality of 50 PR vertical profiles, measured from 0 to 60 cm depth and randomly located on a 6.5 ha sugar cane field in northeastern Brazil. The scaling property of each profile was typified by singularity, and Rényi spectra estimated by the method of moments. The Hurst exponent was used to parameterize the autocorrelation of the vertical PR data sets. The singularity and Rènyi spectra showed that the vertical PR data sets exhibited a well-defined multifractal structure. Hurst exponent values were close to 1, ranging from 0.944 to 0.988, indicating strong persistence in PR variation with soil depth. Also, the Hurst exponent was negatively and significantly correlated to coefficient of variation (CV, skewness and maximum values of the depth-dependent PR. Multifractal analysis added valuable information to describe the spatial arrangement of depth-dependent penetrometer data sets, which was not taken into account by classical statistical indices. Multifractal parameters were mapped over the experimental field and compared with mean and maximum values of PR. Combination of spatial variability survey and multifractal analysis appear to be useful to manage soil compaction.

Multifractal analysis of vertical profiles of soil penetration resistance at the field scale

Science.gov (United States)

Siqueira, G. M.; Silva, E. F. F.; Montenegro, A. A. A.; Vidal Vázquez, E.; Paz-Ferreiro, J.

2013-07-01

Soil penetration resistance (PR) is widely used as an indirect indicator of soil strength. Soil PR is linked to basic soil properties and correlated to root growth and plant production, and as such it is extensively used as a practical tool for assessing soil compaction and to evaluate the effects of soil management. This study investigates how results from multifractal analysis can quantify key elements of depth-dependent soil PR profiles and how this information can be used at the field scale. We analysed multifractality of 50 PR vertical profiles, measured from 0 to 60 cm depth and randomly located on a 6.5 ha sugar cane field in northeastern Brazil. The scaling property of each profile was typified by singularity, and Rényi spectra estimated by the method of moments. The Hurst exponent was used to parameterize the autocorrelation of the vertical PR data sets. The singularity and Rènyi spectra showed that the vertical PR data sets exhibited a well-defined multifractal structure. Hurst exponent values were close to 1, ranging from 0.944 to 0.988, indicating strong persistence in PR variation with soil depth. Also, the Hurst exponent was negatively and significantly correlated to coefficient of variation (CV), skewness and maximum values of the depth-dependent PR. Multifractal analysis added valuable information to describe the spatial arrangement of depth-dependent penetrometer data sets, which was not taken into account by classical statistical indices. Multifractal parameters were mapped over the experimental field and compared with mean and maximum values of PR. Combination of spatial variability survey and multifractal analysis appear to be useful to manage soil compaction.

Multifractals Properties on the Near Infrared Spectroscopy of Human Brain Hemodynamic

Directory of Open Access Journals (Sweden)

Truong Quang Dang Khoa

2012-01-01

Full Text Available Nonlinear physics presents us with a perplexing variety of complicated fractal objects and strange sets. Naturally one wishes to characterize the objects and describe the events occurring on them. Moreover, most time series found in “real-life” applications appear quite noisy. Therefore, at almost every point in time, they cannot be approximated either by the Taylor series or by the Fourier series of just a few terms. Many experimental time series have fractal features and display singular behavior, the so-called singularities. The multifractal spectrum quantifies the degree of fractals in the processes generating the time series. A novel definition is proposed called full-width Hölder exponents that indicate maximum expansion of multifractal spectrum. The obtained results have demonstrated the multifractal structure of near-infrared spectroscopy time series and the evidence for brain imagery activities.

The social class gradient in health in Spain and the health status of the Spanish Roma.

Science.gov (United States)

La Parra Casado, Daniel; Gil González, Diana; de la Torre Esteve, María

2016-10-01

To determine the social class gradient in health in general Spain population and the health status of the Spanish Roma. The National Health Survey of Spanish Roma 2006 (sample size = 993 people; average age: 33.6 years; 53.1% women) and the National Health Surveys for Spain 2003 (sample size: 21,650 people; average age: 45.5 years; 51.2% women) and 2006 (sample size: 29,478 people; average age: 46 years; 50.7% women) are compared. Several indicators were chosen: self-perceived health, activity limitation, chronic diseases, hearing and sight problems, caries, and obesity. Analysis was based on age-standardised rates and logistic regression models. According to most indicators, Roma's health is worse than that of social class IV-V (manual workers). Some indicators show a remarkable difference between Roma and social class IV-V: experiencing three or more health problems, sight problems, and caries, in both sexes, and hearing problems and obesity, in women. Roma people are placed on an extreme position on the social gradient in health, a situation of extreme health inequality.

Multifractal Model of Soil Water Erosion

Science.gov (United States)

Oleshko, Klaudia

2017-04-01

Breaking of solid surface symmetry during the interaction between the rainfall of high erosivity index and internally unstable volcanic soil/vegetation systems, results in roughness increasing as well as fertile horizon loosing. In these areas, the sustainability of management practices depends on the ability to select and implement the precise indicators of soil erodibility and vegetation capacity to protect the system against the extreme damaging precipitation events. Notwithstanding, the complex, non-linear and scaling nature of the phenomena involved in the interaction among the soil, vegetation and precipitation is still not taken into account by the numerous commonly used empirical, mathematical and computer simulation models: for instance, by the universal soil loss equation (USLE). The soil erodibility factor (K-factor) is still measuring by a set of empirical, dimensionless parameters and indexes, without taking into account the scaling (frequently multifractal) origin of a broad range of heterogeneous, anisotropic and dynamical phenomena involved in hydric erosion. Their mapping is not representative of this complex system spatial variability. In our research, we propose to use the toolbox of fractals and multifractals techniques in vista of its ability to measure the scale invariance and type/degree of soil, vegetation and precipitation symmetry breaking. The hydraulic units are chosen as the precise measure of soil/vegetation stability. These units are measured and modeled for soils with contrasting architecture, based on their porosity/permeability (Poroperm) as well as retention capacity relations. The simple Catalog of the most common Poroperm relations is proposed and the main power law relations among the elements of studied system are established and compared for some representative agricultural and natural Biogeosystems of Mexico. All resulted are related with the Mandelbrot' Baby Theorem in order to construct the universal Phase Diagram which

Distinctiveness of the Roma population within CYP2B6 worldwide variation.

Science.gov (United States)

Tomas, Željka; Kuhanec, Antonija; Škarić-Jurić, Tatjana; Petranović, Matea Zajc; Narančić, Nina Smolej; Janićijević, Branka; Salihović, Marijana Peričić

2017-11-01

To determine variation of CYP2B6 gene within the genetically specific Croatian Roma (Gypsy) population originating from India and to examine it in the worldwide perspective. Seven SNP loci (rs12721655, rs2279343, rs28399499, rs34097093, rs3745274, rs7260329 and rs8192709) were genotyped in 439 subjects using Kompetitive Allele Specific PCR (KASP) method. The Croatian Roma took an outlying position in CYP2B6 variation from the worldwide perspective mainly due to their exceptionally high minor allele frequency (MAF) for rs8192709 (12.8%), and lower for rs2279343 (21.1%) compared with south Asian populations. This study provides the first data of several CYP2B6 polymorphisms in Roma population and indicates the need for systematic investigation of the most important pharmacogenes' variants in this large, transnationally isolated population worldwide.

The KRAB Zinc Finger Protein Roma/Zfp157 Is a Critical Regulator of Cell-Cycle Progression and Genomic Stability

Directory of Open Access Journals (Sweden)

Teresa L.F. Ho

2016-04-01

Full Text Available Regulation of DNA replication and cell division is essential for tissue growth and maintenance of genomic integrity and is particularly important in tissues that undergo continuous regeneration such as mammary glands. We have previously shown that disruption of the KRAB-domain zinc finger protein Roma/Zfp157 results in hyperproliferation of mammary epithelial cells (MECs during pregnancy. Here, we delineate the mechanism by which Roma engenders this phenotype. Ablation of Roma in MECs leads to unscheduled proliferation, replication stress, DNA damage, and genomic instability. Furthermore, mouse embryonic fibroblasts (MEFs depleted for Roma exhibit downregulation of p21Cip1 and geminin and have accelerated replication fork velocities, which is accompanied by a high rate of mitotic errors and polyploidy. In contrast, overexpression of Roma in MECs halts cell-cycle progression, whereas siRNA-mediated p21Cip1 knockdown ameliorates, in part, this phenotype. Thus, Roma is an essential regulator of the cell cycle and is required to maintain genomic stability.

Perturbation theory for nematic liquid crystals of axially symmetric molecules: Evaluation of fourth rank orientational order parameter

International Nuclear Information System (INIS)

Singh, K.

1993-11-01

Using a statistical mechanical perturbation theory for isotropic-nematic transition we report a calculation of second and fourth rank orientation order parameters and thermodynamic properties for a model system of prolate ellipsoids of revolution parameterized by its length-to-width ratio. The influence of attractive potential represented by dispersion interaction on a variety of thermodynamic properties is analysed. Inclusion of fourth rank orientational order parameter in calculation slightly changes the transition parameter. (author). 7 refs, 1 tab

Fault diagnosis of rolling bearings based on multifractal detrended fluctuation analysis and Mahalanobis distance criterion

Science.gov (United States)

Lin, Jinshan; Chen, Qian

2013-07-01

Vibration data of faulty rolling bearings are usually nonstationary and nonlinear, and contain fairly weak fault features. As a result, feature extraction of rolling bearing fault data is always an intractable problem and has attracted considerable attention for a long time. This paper introduces multifractal detrended fluctuation analysis (MF-DFA) to analyze bearing vibration data and proposes a novel method for fault diagnosis of rolling bearings based on MF-DFA and Mahalanobis distance criterion (MDC). MF-DFA, an extension of monofractal DFA, is a powerful tool for uncovering the nonlinear dynamical characteristics buried in nonstationary time series and can capture minor changes of complex system conditions. To begin with, by MF-DFA, multifractality of bearing fault data was quantified with the generalized Hurst exponent, the scaling exponent and the multifractal spectrum. Consequently, controlled by essentially different dynamical mechanisms, the multifractality of four heterogeneous bearing fault data is significantly different; by contrast, controlled by slightly different dynamical mechanisms, the multifractality of homogeneous bearing fault data with different fault diameters is significantly or slightly different depending on different types of bearing faults. Therefore, the multifractal spectrum, as a set of parameters describing multifractality of time series, can be employed to characterize different types and severity of bearing faults. Subsequently, five characteristic parameters sensitive to changes of bearing fault conditions were extracted from the multifractal spectrum and utilized to construct fault features of bearing fault data. Moreover, Hilbert transform based envelope analysis, empirical mode decomposition (EMD) and wavelet transform (WT) were utilized to study the same bearing fault data. Also, the kurtosis and the peak levels of the EMD or the WT component corresponding to the bearing tones in the frequency domain were carefully checked

(Multi)fractality of Earthquakes by use of Wavelet Analysis

Science.gov (United States)

Enescu, B.; Ito, K.; Struzik, Z. R.

2002-12-01

The fractal character of earthquakes' occurrence, in time, space or energy, has by now been established beyond doubt and is in agreement with modern models of seismicity. Moreover, the cascade-like generation process of earthquakes -with one "main" shock followed by many aftershocks, having their own aftershocks- may well be described through multifractal analysis, well suited for dealing with such multiplicative processes. The (multi)fractal character of seismicity has been analysed so far by using traditional techniques, like the box-counting and correlation function algorithms. This work introduces a new approach for characterising the multifractal patterns of seismicity. The use of wavelet analysis, in particular of the wavelet transform modulus maxima, to multifractal analysis was pioneered by Arneodo et al. (1991, 1995) and applied successfully in diverse fields, such as the study of turbulence, the DNA sequences or the heart rate dynamics. The wavelets act like a microscope, revealing details about the analysed data at different times and scales. We introduce and perform such an analysis on the occurrence time of earthquakes and show its advantages. In particular, we analyse shallow seismicity, characterised by a high aftershock "productivity", as well as intermediate and deep seismic activity, known for its scarcity of aftershocks. We examine as well declustered (aftershocks removed) versions of seismic catalogues. Our preliminary results show some degree of multifractality for the undeclustered, shallow seismicity. On the other hand, at large scales, we detect a monofractal scaling behaviour, clearly put in evidence for the declustered, shallow seismic activity. Moreover, some of the declustered sequences show a long-range dependent (LRD) behaviour, characterised by a Hurst exponent, H > 0.5, in contrast with the memory-less, Poissonian model. We demonstrate that the LRD is a genuine characteristic and is not an effect of the time series probability

Singularity spectra of fractional Brownian motions as a multi-fractal

International Nuclear Information System (INIS)

Kim, T.S.; Kim, S.

2004-01-01

Fractional Brownian motion acts as a random process with statistical self-similarity in time and self-affinity in shape. From these properties, the complicated patterns can be suitably represented by it with a minimal parameter and less memory. By considering its statistical property through the power spectrum density we can see that this process is not stationary, even though its differential motion is stationary. So in this paper, by taking the wavelet transform instead of Fourier transformation we investigate its multi-fractal spectrum as a multi-fractal model

Intermittency and multifractional Brownian character of geomagnetic time series

Directory of Open Access Journals (Sweden)

G. Consolini

2013-07-01

Full Text Available The Earth's magnetosphere exhibits a complex behavior in response to the solar wind conditions. This behavior, which is described in terms of mutifractional Brownian motions, could be the consequence of the occurrence of dynamical phase transitions. On the other hand, it has been shown that the dynamics of the geomagnetic signals is also characterized by intermittency at the smallest temporal scales. Here, we focus on the existence of a possible relationship in the geomagnetic time series between the multifractional Brownian motion character and the occurrence of intermittency. In detail, we investigate the multifractional nature of two long time series of the horizontal intensity of the Earth's magnetic field as measured at L'Aquila Geomagnetic Observatory during two years (2001 and 2008, which correspond to different conditions of solar activity. We propose a possible double origin of the intermittent character of the small-scale magnetic field fluctuations, which is related to both the multifractional nature of the geomagnetic field and the intermittent character of the disturbance level. Our results suggest a more complex nature of the geomagnetic response to solar wind changes than previously thought.

ASSESSMENT OF THE INDOOR ENVIRONMENT AND IMPLICATIONS FOR HEALTH IN ROMA VILLAGES IN SLOVAKIA AND ROMANIA

Science.gov (United States)

Majdan, Marek; Coman, Alexandru; Gallová, Eva; Ďuricová, Janka; Kállayová, Daniela; Kvaková, Mária; Bošák, Ľuboš

2013-01-01

SUMMARY Objectives The objective of this paper is to provide information on indoor air quality and on the quality of the broader indoor environment of the houses in Roma villages in Slovakia and Romania and to discuss possible implications for health. Methods Indoor air was sampled in 11 houses in a Romanian Roma village and in 19 houses in a Slovakian Roma village. Levels of Carbon Monoxide (CO), Carbon Dioxide (CO2), total particulate matter (PM), temperature and humidity were measured. A questionnaire and a checklist were used to obtain additional information on the indoor environment and behavioural factors. We have sampled the same houses in winter and in summer. Results Levels of CO and CO2 were higher in winter in both countries as compared to summer. The limit value of 10 mg/m3 CO was exceeded in a few cases in both countries. In general, levels of CO, CO2 and PM were higher in Romania. Further environmental and behavioural hazards such as indoor smoking, pets inside or lack of ventilation were found. The reported self-perceived quality of the indoor environment was poor in many aspects. Conclusions Our findings of CO, CO2 and PM levels suggest that indoor air pollution in Roma settlements has the potential to be a health threat. The fact that the inhabitants spend a relatively long time inside the houses and that a number of additional environmental and behavioural hazards were identified by our study emphasizes the importance of the indoor air quality for health and thus priority attention should be paid to these issues by health authorities and researchers. Further research is essential and study designs must consider cultural background and specific characteristics of the community, especially in order to obtain valid data on health outcomes. PMID:23285520

Fractional governing equations of transient groundwater flow in confined aquifers with multi-fractional dimensions in fractional time

OpenAIRE

M. L. Kavvas; T. Tu; A. Ercan; J. Polsinelli

2017-01-01

Using fractional calculus, a dimensionally consistent governing equation of transient, saturated groundwater flow in fractional time in a multi-fractional confined aquifer is developed. First, a dimensionally consistent continuity equation for transient saturated groundwater flow in fractional time and in a multi-fractional, multidimensional confined aquifer is developed. For the equation of water flux within a multi-fractional multidimensional confined aquifer, a dimensionally...

Multifractality in edge localized modes in Japan Atomic Energy Research Institute Tokamak-60 Upgrade

International Nuclear Information System (INIS)

Bak, P.E.; Asakura, N.; Miura, Y.; Nakano, T.; Yoshino, R.

2001-01-01

The temporal losses of confinement during edge localized modes in the Japan Atomic Energy Research Institute Tokamak-60 Upgrade (JT-60U) show multifractal scaling and the spectra are generally smooth, but in some cases there are signs of discontinuous derivatives. Dynamics of the Sugama-Horton model, interpreted as edge localized modes, also display multifractal scaling. The spectra display singularities in the derivative, which can be interpreted as a phase transition. It is argued that the multifractal spectra of edge localized modes can be used to discriminate between different experimental discharges and validate edge localized mode models

Multifractal analysis of visibility graph-based Ito-related connectivity time series.

Science.gov (United States)

Czechowski, Zbigniew; Lovallo, Michele; Telesca, Luciano

2016-02-01

In this study, we investigate multifractal properties of connectivity time series resulting from the visibility graph applied to normally distributed time series generated by the Ito equations with multiplicative power-law noise. We show that multifractality of the connectivity time series (i.e., the series of numbers of links outgoing any node) increases with the exponent of the power-law noise. The multifractality of the connectivity time series could be due to the width of connectivity degree distribution that can be related to the exit time of the associated Ito time series. Furthermore, the connectivity time series are characterized by persistence, although the original Ito time series are random; this is due to the procedure of visibility graph that, connecting the values of the time series, generates persistence but destroys most of the nonlinear correlations. Moreover, the visibility graph is sensitive for detecting wide "depressions" in input time series.

Empirical method to measure stochasticity and multifractality in nonlinear time series

Science.gov (United States)

Lin, Chih-Hao; Chang, Chia-Seng; Li, Sai-Ping

2013-12-01

An empirical algorithm is used here to study the stochastic and multifractal nature of nonlinear time series. A parameter can be defined to quantitatively measure the deviation of the time series from a Wiener process so that the stochasticity of different time series can be compared. The local volatility of the time series under study can be constructed using this algorithm, and the multifractal structure of the time series can be analyzed by using this local volatility. As an example, we employ this method to analyze financial time series from different stock markets. The result shows that while developed markets evolve very much like an Ito process, the emergent markets are far from efficient. Differences about the multifractal structures and leverage effects between developed and emergent markets are discussed. The algorithm used here can be applied in a similar fashion to study time series of other complex systems.

Intergenerational transmission of ethnic identity and life satisfaction of Roma minority adolescents and their parents.

Science.gov (United States)

Dimitrova, Radosveta; Ferrer-Wreder, Laura; Trost, Kari

2015-12-01

This study investigates intergeneration transmission of ethnic identity as a resource for life satisfaction of Roma adolescents and their parents. Historically, Roma represent the largest ethnic minority in Europe. They have been exposed to severe discrimination, social exclusion, and poverty. Therefore, identifying resources for their life satisfaction is theoretically and practically important. The present study included 1093 participants, of which there were 171 Roma adolescents (age: M = 14.96 years, SD = 1.85), 155 mothers (age: M = 36.16 years, SD = 5.77) and 123 fathers (age: M = 39.68 years, SD = 6.06). Further, a comparison group of 248 mainstream adolescents with their mothers (n = 221) and fathers (n = 175) was also included in the study. Adolescents and their parents provided data on ethnic identity (MEIM; Phinney, 1992) and life satisfaction (SWLS; Diener, Emmons, Larsen, & Griffin, 1985). Results indicated that Roma youth were lower on endorsement of ethnic identity and average on life satisfaction compared to their mainstream peers. A structural equation model showed that ethnic identity was a positive predictor of life satisfaction for both adolescents and their Roma parents. Furthermore, parents' ethnic identity was a predictor of adolescent life satisfaction. We concluded that for Roma youth and their parents, ethnic identity represents a salient source for life satisfaction and an intergenerational continuity of identity and life satisfaction exists. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Ethnic Housing Segregation and the Roma/Gypsy population

DEFF Research Database (Denmark)

Alves, Sonia

during phases of advanced urban decline, the existence of ethnic enclaves and concentrated poverty has led to housing demolition and rehousing, in many cases with controversial results. The relevance of the link between ethnic segregation and integration is known. On the one hand, people create......Questions of spatial segregation and over-representation of ethnic minority groups with weak connections to the labour market are central to the political and policy agenda across Europe and academic studies in the fields of housing and urban regeneration. In some countries, the spatial...... review literature that presents the empirical results of research conducted in different locations of Portugal but has in common processes of rehousing of the Gypsy/Roma population in urban areas. I compare these results with those I obtained in field work in Porto where I interviewed Gypsy/Roma people...

MORTALITY PATTERNS OF ROMA POPULATION IN OLTENIA REGION

Directory of Open Access Journals (Sweden)

MIHAELA PREDA

2011-11-01

Full Text Available Mortality is the only indicator that presents a series of aspects meant to emphasize both the demographic evolution of a population and its social determinants that confers it an increasing or decreasing tendency associated in most cases with a specific level of development.Mortality, through the manifestation of present variations is caused by a series of socio-economic factors such as the level of education with consequences on the attitude towards the health care, the population age, as well as by certain exogenous factors related to the geographic environment.The analysis of the general mortality among the Roma population intends to grasp a series of variables specific for this indicator; the values that the general mortality registers within the Roma population are in the trend of the values for this indicator measured for the overall population.

Multifractal detrended cross-correlations between crude oil market and Chinese ten sector stock markets

Science.gov (United States)

Yang, Liansheng; Zhu, Yingming; Wang, Yudong; Wang, Yiqi

2016-11-01

Based on the daily price data of spot prices of West Texas Intermediate (WTI) crude oil and ten CSI300 sector indices in China, we apply multifractal detrended cross-correlation analysis (MF-DCCA) method to investigate the cross-correlations between crude oil and Chinese sector stock markets. We find that the strength of multifractality between WTI crude oil and energy sector stock market is the highest, followed by the strength of multifractality between WTI crude oil and financial sector market, which reflects a close connection between energy and financial market. Then we do vector autoregression (VAR) analysis to capture the interdependencies among the multiple time series. By comparing the strength of multifractality for original data and residual errors of VAR model, we get a conclusion that vector auto-regression (VAR) model could not be used to describe the dynamics of the cross-correlations between WTI crude oil and the ten sector stock markets.

Prevalence of Chlamydia trachomatis Infection and Its Association with Sexual Behaviour and Alcohol Use in the Population Living in Separated and Segregated Roma Settlements in Eastern Slovakia.

Science.gov (United States)

Babinská, Ingrid; Halánová, Monika; Kalinová, Zuzana; Čechová, Lenka; Čisláková, Lýdia; Madarasová Gecková, Andrea

2017-12-14

The aim of the study was to explore sexual behaviour and the occurrence of Chlamydia trachomatis (CT) infection in the population living in Roma settlements compared to the majority population in Slovakia and to assess the association between alcohol use and sexual behaviour within both populations. A cross-sectional population-based Hepa-Meta study was conducted in Slovakia in 2011. The final sample comprised 452 Roma and 403 non-Roma respondents. The occurrence of CT was detected by direct proof of the pathogen by PCR. The association between alcohol use and the prevalence of risky sexual behaviour were assessed using a logistic regression. First intercourse at age 15 or younger was reported by 27.9% of Roma (vs. 4.5% of non-Roma); 93.4% of Roma (vs. 77.9% of non-Roma) used condom inconsistently, 22.8% of Roma (vs. 43.9% of non-Roma) used a condom for protection from unwanted pregnancies and only 8.8% of Roma (vs. 21.8% of non-Roma) due to protection against infectious diseases. However, Roma reported having had five or more sexual partners less often compared to the majority (11.5% of Roma vs. 20.6% of non-Roma). Binge drinking at least once a month was associated with a higher number of sexual partners in both groups, but not with condom non-use. The prevalence of CT infection in the Roma population was higher (3.8%) compared to non-Roma (2.7%); however, the difference was not statistically significant. Our study found no differences in the prevalence of CT infection between Roma and non-Roma despite differences in sexual behaviour. Roma begin their sexual life earlier and have unprotected sex more often, but on the other hand, they seem to be much more restrained in terms of the number of sexual partners compared to the majority population.

Multiscale characterization of pore spaces using multifractals analysis of scanning electronic microscopy images of carbonates

Directory of Open Access Journals (Sweden)

M. S. Jouini

2011-12-01

Full Text Available Pore spaces heterogeneity in carbonates rocks has long been identified as an important factor impacting reservoir productivity. In this paper, we study the heterogeneity of carbonate rocks pore spaces based on the image analysis of scanning electron microscopy (SEM data acquired at various magnifications. Sixty images of twelve carbonate samples from a reservoir in the Middle East were analyzed. First, pore spaces were extracted from SEM images using a segmentation technique based on watershed algorithm. Pores geometries revealed a multifractal behavior at various magnifications from 800x to 12 000x. In addition, the singularity spectrum provided quantitative values that describe the degree of heterogeneity in the carbonates samples. Moreover, for the majority of the analyzed samples, we found low variations (around 5% in the multifractal dimensions for magnifications between 1700x and 12 000x. Finally, these results demonstrate that multifractal analysis could be an appropriate tool for characterizing quantitatively the heterogeneity of carbonate pore spaces geometries. However, our findings show that magnification has an impact on multifractal dimensions, revealing the limit of applicability of multifractal descriptions for these natural structures.

Multifractal scaling analysis of autopoisoning reactions over a rough surface

International Nuclear Information System (INIS)

Chaudhari, Ajay; Yan, Ching-Cher Sanders; Lee, S.-L.

2003-01-01

Decay type diffusion-limited reactions (DLR) over a rough surface generated by a random deposition model were performed. To study the effect of the decay profile on the reaction probability distribution (RPD), multifractal scaling analysis has been carried out. The dynamics of these autopoisoning reactions are controlled by the two parameters in the decay function, namely, the initial sticking probability (P ini ) of every site and the decay rate (m). The smaller the decay rate, the narrower is the range of α values in the α-f(α) multifractal spectrum. The results are compared with the earlier work of DLR over a surface of diffusion-limited aggregation (DLA). We also considered here the autopoisoning reactions over a smooth surface for comparing our results, which show clearly how the roughness affects the chemical reactions. The q-τ(q) multifractal curves for the smooth surface are linear whereas those for the rough surface are nonlinear. The range of α values in the case of a rough surface is wider than that of the smooth surface

Is There Any Light in the Tunnel? On the Drawbacks of Roma Educational Integration in Bulgaria

Directory of Open Access Journals (Sweden)

Milenkova, Valentina

2017-01-01

Full Text Available The main objective of this paper is to identify the issues, which have led to Roma exclusion from the mainstream education. The first part of the paper is focused on data, correlating unequal educational opportunities and the ethnicity factor. The text presents an insight into the widely argued Roma dropout phenomenon. Different sets of reasons for dropping out from school are being discussed, i.e. educational, ethnic and cultural, economic, and family reasons. In addition, the article reflects on the retrograde beliefs of the majority population as a prerequisite for Roma reluctance towards continuing education. Moreover, the article puts forward a review on the most recent key policy measures for equal educational opportunities, targeting the Roma. Various aspects of adopted policy interventions for stimulating educational inclusion are illustrated, and supplemented by a critical analysis. The authors conclude that the required strategic actions, targeting educational equity for marginalized social groups, such as the Roma, have been indeed formulated by the stakeholders; yet, certain shortcomings have been noticed and these are primarily linked to the practical implementation of the national documents into real actions.

EGS Richardson AGU Chapman NVAG3 Conference: Nonlinear Variability in Geophysics: scaling and multifractal processes

Directory of Open Access Journals (Sweden)

D. Schertzer

1994-01-01

department and the principal of a college. In 1940, he retired to do research on war, which was published posthumously in book form (Richardson, 1963. This latter work is testimony to the trauma caused by the two World Wars and which led some scientists including Richardson to use their skills in rational attempts to eradicate the source of conflict. Unfortunately, this remains an open field of research. 3. The contributions in this special issue Perhaps the area of geophysics where scaling ideas have the longest history, and where they have made the largest impact in the last few years, is turbulence. The paper by Tsinober is an example where geometric fractal ideas are used to deduce corrections to standard dimensional analysis results for turbulence. Based on local spontaneous breaking of isotropy of turbulent flows, the fractal notion is used in order to deduce diffusion laws (anomalous with respect to the Richardson law. It is argued that his law is ubiquitous from the atmospheric boundary layer to the stratosphere. The asymptotic intermittency exponent i hypothesized to be not only finite but to be determined by the angular momentum flux. Schmitt et al., Chigirinskaya et al. and Lazarev et al. apply statistical multifractal notions to atmospheric turbulence. In the former, the formal analogy between multifractals and thermodynamics is exploited, in particular to confirm theoretical predictions that sample-size dependent multifractal phase transitions occur. While this quantitatively explains the behavior of the most extreme turbulent events, it suggests that - contrary to the type of multifractals most commonly discussed in the literature which are bounded - more violent (unbounded multifractals are indeed present in the atmospheric wind field. Chigirinskaya et al. use a tropical rather than mid-latitude set to study the extreme fluctuations form yet another angle: That of coherent structures, which, in the multifractal framework, are identified with singularities of

EGS Richardson AGU Chapman NVAG3 Conference: Nonlinear Variability in Geophysics: scaling and multifractal processes

Science.gov (United States)

Schertzer, D.; Lovejoy, S.

department and the principal of a college. In 1940, he retired to do research on war, which was published posthumously in book form (Richardson, 1963). This latter work is testimony to the trauma caused by the two World Wars and which led some scientists including Richardson to use their skills in rational attempts to eradicate the source of conflict. Unfortunately, this remains an open field of research. 3. The contributions in this special issue Perhaps the area of geophysics where scaling ideas have the longest history, and where they have made the largest impact in the last few years, is turbulence. The paper by Tsinober is an example where geometric fractal ideas are used to deduce corrections to standard dimensional analysis results for turbulence. Based on local spontaneous breaking of isotropy of turbulent flows, the fractal notion is used in order to deduce diffusion laws (anomalous with respect to the Richardson law). It is argued that his law is ubiquitous from the atmospheric boundary layer to the stratosphere. The asymptotic intermittency exponent i hypothesized to be not only finite but to be determined by the angular momentum flux. Schmitt et al., Chigirinskaya et al. and Lazarev et al. apply statistical multifractal notions to atmospheric turbulence. In the former, the formal analogy between multifractals and thermodynamics is exploited, in particular to confirm theoretical predictions that sample-size dependent multifractal phase transitions occur. While this quantitatively explains the behavior of the most extreme turbulent events, it suggests that - contrary to the type of multifractals most commonly discussed in the literature which are bounded - more violent (unbounded) multifractals are indeed present in the atmospheric wind field. Chigirinskaya et al. use a tropical rather than mid-latitude set to study the extreme fluctuations form yet another angle: That of coherent structures, which, in the multifractal framework, are identified with singularities

Is the Definition of Roma an Important Matter? The Parallel Application of Self and External Classification of Ethnicity in a Population-Based Health Interview Survey.

Science.gov (United States)

Janka, Eszter Anna; Vincze, Ferenc; Ádány, Róza; Sándor, János

2018-02-16

The Roma population is typified by a poor and, due to difficulties in ethnicity assessment, poorly documented health status. We aimed to compare the usefulness of self-reporting and observer-reporting in Roma classification for surveys investigating differences between Roma and non-Roma populations. Both self-reporting and observer-reporting of Roma ethnicity were applied in a population-based health interview survey. A questionnaire was completed by 1849 people aged 18-64 years; this questionnaire provided information on 52 indicators (morbidity, functionality, lifestyle, social capital, accidents, healthcare use) indicators. Multivariate logistic regression models controlling for age, sex, education and employment were used to produce indicators for differences between the self-reported Roma ( N = 124) and non-Roma ( N = 1725) populations, as well as between observer-reported Roma ( N = 179) and non-Roma populations ( N = 1670). Differences between interviewer-reported and self-reported individuals of Roma ethnicity in statistical inferences were observed for only seven indicators. The self-reporting approach was more sensitive for two indicators, and the observer-reported assessment for five indicators. Based on our results, the self-reported identity can be considered as a useful approach, and the application of observer-reporting cannot considerably increase the usefulness of a survey, because the differences between Roma and non-Roma individuals are much bigger than the differences between indicators produced by self-reported or observer-reported data on individuals of Roma ethnicity.

Is the Definition of Roma an Important Matter? The Parallel Application of Self and External Classification of Ethnicity in a Population-Based Health Interview Survey

Directory of Open Access Journals (Sweden)

Eszter Anna Janka

2018-02-01

Full Text Available The Roma population is typified by a poor and, due to difficulties in ethnicity assessment, poorly documented health status. We aimed to compare the usefulness of self-reporting and observer-reporting in Roma classification for surveys investigating differences between Roma and non-Roma populations. Both self-reporting and observer-reporting of Roma ethnicity were applied in a population-based health interview survey. A questionnaire was completed by 1849 people aged 18–64 years; this questionnaire provided information on 52 indicators (morbidity, functionality, lifestyle, social capital, accidents, healthcare use indicators. Multivariate logistic regression models controlling for age, sex, education and employment were used to produce indicators for differences between the self-reported Roma (N = 124 and non-Roma (N = 1725 populations, as well as between observer-reported Roma (N = 179 and non-Roma populations (N = 1670. Differences between interviewer-reported and self-reported individuals of Roma ethnicity in statistical inferences were observed for only seven indicators. The self-reporting approach was more sensitive for two indicators, and the observer-reported assessment for five indicators. Based on our results, the self-reported identity can be considered as a useful approach, and the application of observer-reporting cannot considerably increase the usefulness of a survey, because the differences between Roma and non-Roma individuals are much bigger than the differences between indicators produced by self-reported or observer-reported data on individuals of Roma ethnicity.

Multifractal characterization of single wall carbon nanotube thin films surface upon exposure to optical parametric oscillator laser irradiation

International Nuclear Information System (INIS)

Ţălu, Ştefan; Marković, Zoran; Stach, Sebastian; Todorović Marković, B.; Ţălu, Mihai

2014-01-01

This study presents a multifractal approach, obtained with atomic force microscopy analysis, to characterize the structural evolution of single wall carbon nanotube thin films upon exposure to optical parametric oscillator laser irradiation at wavelength of 430 nm. Microstructure and morphological changes of carbon nanotube films deposited on different substrates (mica and TGX grating) were recorded by atomic force microscope. A detailed methodology for surface multifractal characterization, which may be applied for atomic force microscopy data, was presented. Multifractal analysis of surface roughness revealed that carbon nanotube films surface has a multifractal geometry at various magnifications. The generalized dimension D q and the singularity spectrum f(α) provided quantitative values that characterize the local scale properties of carbon nanotube films surface morphology at nanometer scale. Multifractal analysis provides different yet complementary information to that offered by traditional surface statistical parameters.

SpikeTemp: An Enhanced Rank-Order-Based Learning Approach for Spiking Neural Networks With Adaptive Structure.

Science.gov (United States)

Wang, Jinling; Belatreche, Ammar; Maguire, Liam P; McGinnity, Thomas Martin

2017-01-01

This paper presents an enhanced rank-order-based learning algorithm, called SpikeTemp, for spiking neural networks (SNNs) with a dynamically adaptive structure. The trained feed-forward SNN consists of two layers of spiking neurons: 1) an encoding layer which temporally encodes real-valued features into spatio-temporal spike patterns and 2) an output layer of dynamically grown neurons which perform spatio-temporal classification. Both Gaussian receptive fields and square cosine population encoding schemes are employed to encode real-valued features into spatio-temporal spike patterns. Unlike the rank-order-based learning approach, SpikeTemp uses the precise times of the incoming spikes for adjusting the synaptic weights such that early spikes result in a large weight change and late spikes lead to a smaller weight change. This removes the need to rank all the incoming spikes and, thus, reduces the computational cost of SpikeTemp. The proposed SpikeTemp algorithm is demonstrated on several benchmark data sets and on an image recognition task. The results show that SpikeTemp can achieve better classification performance and is much faster than the existing rank-order-based learning approach. In addition, the number of output neurons is much smaller when the square cosine encoding scheme is employed. Furthermore, SpikeTemp is benchmarked against a selection of existing machine learning algorithms, and the results demonstrate the ability of SpikeTemp to classify different data sets after just one presentation of the training samples with comparable classification performance.

Multifractality and herding behavior in the Japanese stock market

International Nuclear Information System (INIS)

Cajueiro, Daniel O.; Tabak, Benjamin M.

2009-01-01

In this paper we present evidence of multifractality and herding behavior for a large set of Japanese stocks traded in the Tokyo Stock Exchange. We find evidence that herding behavior occurs in periods of extreme market movements. Therefore, based on the intuition behind the tests to detect herding phenomenon developed, for instance, in Christie and Huang [Christie W, Huang R. Following the pied pier: do individual returns herd around the market? Financ Analysts J 1995;51:31-7] and Chang et al. [Chang EC, Cheng JW, Khorana A. Examination of herd behavior in equity markets: an international perspective. J Bank Finance 2000;24:1651-99], we suggest that herding behavior may be one of the causes of multifractality.

[Sexual and reproductive health in Roma women: the family planning programme of Polígono Sur in Seville (Spain)].

Science.gov (United States)

Escobar-Ballesta, Marta; García-Ramírez, Manuel; Albar-Marín, M ª Jesús; Paloma, Virginia

2018-04-05

To describe the challenges, resources and strategies of the staff of the family planning programme of the Polígono Sur Healthcare Centre in Seville (Spain) in their care of Roma women. This is a descriptive study in which in-depth interviews and discussion groups were held with all programme professionals, including a documentary review of the programme. The information was analyzed based on the Roma Health Integration Policy Index, a tool that evaluates the entitlement, accessibility, sensitivity and capacity for change of health programmes for the Roma population. The professionals encountered multiple challenges to implement the family planning programme with Roma women due to the characteristics of the users and the low sensitivity of the programme towards them. The absence of specific actions for Roma women within the family planning programme, agreed to by the healthcare district, obliges professionals to develop adaptations and strategies to ensure quality sexual and reproductive health services for their users. It is necessary to adapt sexual and reproductive health programmes targeted at Roma women by (a) detecting, evaluating, systematizing and disseminating good practices, (b) developing actions that address the multiple vulnerabilities of Roma women, (c) acknowledging professionals who advocate for the health of these women within their organizations, and (d) promoting reproductive justice as the goal of these programmes. Copyright © 2018 SESPAS. All rights reserved.

Genetic studies of the Roma (Gypsies: a review

Directory of Open Access Journals (Sweden)

Gresham David

2001-04-01

Full Text Available Abstract Background Data provided by the social sciences as well as genetic research suggest that the 8-10 million Roma (Gypsies who live in Europe today are best described as a conglomerate of genetically isolated founder populations. The relationship between the traditional social structure observed by the Roma, where the Group is the primary unit, and the boundaries, demographic history and biological relatedness of the diverse founder populations appears complex and has not been addressed by population genetic studies. Results Recent medical genetic research has identified a number of novel, or previously known but rare conditions, caused by private founder mutations. A summary of the findings, provided in this review, should assist diagnosis and counselling in affected families, and promote future collaborative research. The available incomplete epidemiological data suggest a non-random distribution of disease-causing mutations among Romani groups. Conclusion Although far from systematic, the published information indicates that medical genetics has an important role to play in improving the health of this underprivileged and forgotten people of Europe. Reported carrier rates for some Mendelian disorders are in the range of 5 -15%, sufficient to justify newborn screening and early treatment, or community-based education and carrier testing programs for disorders where no therapy is currently available. To be most productive, future studies of the epidemiology of single gene disorders should take social organisation and cultural anthropology into consideration, thus allowing the targeting of public health programs and contributing to the understanding of population structure and demographic history of the Roma.

Quantitative assessment of submicron scale anisotropy in tissue multifractality by scattering Mueller matrix in the framework of Born approximation

Science.gov (United States)

Das, Nandan Kumar; Dey, Rajib; Chakraborty, Semanti; Panigrahi, Prasanta K.; Meglinski, Igor; Ghosh, Nirmalya

2018-04-01

A number of tissue-like disordered media exhibit local anisotropy of scattering in the scaling behavior. Scaling behavior contains wealth of fractal or multifractal properties. We demonstrate that the spatial dielectric fluctuations in a sample of biological tissue exhibit multifractal anisotropy. Multifractal anisotropy encoded in the wavelength variation of the light scattering Mueller matrix and manifesting as an intriguing spectral diattenuation effect. We developed an inverse method for the quantitative assessment of the multifractal anisotropy. The method is based on the processing of relevant Mueller matrix elements in Fourier domain by using Born approximation, followed by the multifractal analysis. The approach promises for probing subtle micro-structural changes in biological tissues associated with the cancer and precancer, as well as for non-destructive characterization of a wide range of scattering materials.

Assessing the association between 25-OH vitamin D levels and ROMA score in a population of obese women.

Science.gov (United States)

Anastasi, E; Capoccia, D; Granato, T; Viggiani, V; Tartaglione, S; Manganaro, L; Angeloni, A; Leonetti, F

2016-01-01

The “Risk of Malignancy Algorithm” (ROMA) combines the diagnostic power of the CA125 and HE4 markers with menopausal status to predict the risk for developing epithelial ovarian cancer (EOC). The aim of this study was to evaluate the association between 25-OH vitamin D levels and ROMA score in obese women. One hundred and eighteen patients with a Body Mass Index (BMI) > 30 kg/m2 (Group 1) and 80 women with a BMI less than 25 kg / m² (Group 2) were studied. The 25-OH vitamin D was quantified with LUMIPULSE® G 1200. As a threshold value, identified by ROC curve analysis, 20.2 ng/ mL (sensitivity 73.3%, specificity 84%) was chosen corresponding to the limit between sufficient and insufficient 25-OH vitamin D according to the World Health Organization (WHO). Low 25-OH vitamin D levels were observed in 64% of obese women and in 11% of normal-weight women (p less than 0.001). ROMA score above 13% was detected only in obese women (19%). An association between low levels of 25-OH vitamin D and ROMA score was observed. Indeed, 64% of obese women with ROMA score >13% had concomitant insufficient levels of 25-OH vitamin D, while only 36% of obese women with ROMA score >13% had sufficient 25-OH vitamin D levels (p less than 0.0001). This study suggests that the deficiency of 25- OH vitamin D in obese women has a possible correlation with high ROMA score.

Seroprevalence of Hepatitis E Virus in Roma Settlements: A Comparison with the General Population in Slovakia.

Science.gov (United States)

Halánová, Monika; Veseliny, Eduard; Kalinová, Zuzana; Jarčuška, Peter; Janičko, Martin; Urbančíková, Ingrid; Pella, Daniel; Dražilová, Sylvia; Babinská, Ingrid

2018-05-03

Hepatitis E infection is one of the most frequent causes of acute hepatitis in the world. Currently five human genotypes with different geographical distributions and distinct epidemiologic patterns are identified. In Slovakia, only rare cases of hepatitis E have been reported in past years. Because the most important risk factors associated with HEV infection include consumption of contaminated pork meat and poor hygienic standards, the aim of the study was to evaluate the prevalence of anti-HEV total antibodies and the main risk factors for HEV in the population living in separated and segregated Roma settlements ( n = 195), which represent places with increased risk of infection in Slovakia and to compare it with the prevalence in the general population ( n = 69). Of 264 respondents included in the study, 47 (17.8%) showed positivity for anti-HEV antibodies, 42 of whom were Roma (21.5%, n = 195) and 5 (7.2%, n = 69) non-Roma. The population living in Roma settlements lives in poorer conditions and are at higher risk of HEV in comparison to the general population. However, differences in living conditions within the settlements do not contributed to lower risk of HEV antibody prevalence between Roma living in settlements.

Multifractality as a Measure of Complexity in Solar Flare Activity

Science.gov (United States)

Sen, Asok K.

2007-03-01

In this paper we use the notion of multifractality to describe the complexity in H α flare activity during the solar cycles 21, 22, and 23. Both northern and southern hemisphere flare indices are analyzed. Multifractal behavior of the flare activity is characterized by calculating the singularity spectrum of the daily flare index time series in terms of the Hölder exponent. The broadness of the singularity spectrum gives a measure of the degree of multifractality or complexity in the flare index data. The broader the spectrum, the richer and more complex is the structure with a higher degree of multifractality. Using this broadness measure, complexity in the flare index data is compared between the northern and southern hemispheres in each of the three cycles, and among the three cycles in each of the two hemispheres. Other parameters of the singularity spectrum can also provide information about the fractal properties of the flare index data. For instance, an asymmetry to the left or right in the singularity spectrum indicates a dominance of high or low fractal exponents, respectively, reflecting a relative abundance of large or small fluctuations in the total energy emitted by the flares. Our results reveal that in the even (22nd) cycle the singularity spectra are very similar for the northern and southern hemispheres, whereas in the odd cycles (21st and 23rd) they differ significantly. In particular, we find that in cycle 21, the northern hemisphere flare index data have higher complexity than its southern counterpart, with an opposite pattern prevailing in cycle 23. Furthermore, small-scale fluctuations in the flare index time series are predominant in the northern hemisphere in the 21st cycle and are predominant in the southern hemisphere in the 23rd cycle. Based on these findings one might suggest that, from cycle to cycle, there exists a smooth switching between the northern and southern hemispheres in the multifractality of the flaring process. This new

Ship detection in satellite imagery using rank-order greyscale hit-or-miss transforms

Energy Technology Data Exchange (ETDEWEB)

Harvey, Neal R [Los Alamos National Laboratory; Porter, Reid B [Los Alamos National Laboratory; Theiler, James [Los Alamos National Laboratory

2010-01-01

Ship detection from satellite imagery is something that has great utility in various communities. Knowing where ships are and their types provides useful intelligence information. However, detecting and recognizing ships is a difficult problem. Existing techniques suffer from too many false-alarms. We describe approaches we have taken in trying to build ship detection algorithms that have reduced false alarms. Our approach uses a version of the grayscale morphological Hit-or-Miss transform. While this is well known and used in its standard form, we use a version in which we use a rank-order selection for the dilation and erosion parts of the transform, instead of the standard maximum and minimum operators. This provides some slack in the fitting that the algorithm employs and provides a method for tuning the algorithm's performance for particular detection problems. We describe our algorithms, show the effect of the rank-order parameter on the algorithm's performance and illustrate the use of this approach for real ship detection problems with panchromatic satellite imagery.

VAiRoma: A Visual Analytics System for Making Sense of Places, Times, and Events in Roman History.

Science.gov (United States)

Cho, Isaac; Dou, Wewnen; Wang, Derek Xiaoyu; Sauda, Eric; Ribarsky, William

2016-01-01

Learning and gaining knowledge of Roman history is an area of interest for students and citizens at large. This is an example of a subject with great sweep (with many interrelated sub-topics over, in this case, a 3,000 year history) that is hard to grasp by any individual and, in its full detail, is not available as a coherent story. In this paper, we propose a visual analytics approach to construct a data driven view of Roman history based on a large collection of Wikipedia articles. Extracting and enabling the discovery of useful knowledge on events, places, times, and their connections from large amounts of textual data has always been a challenging task. To this aim, we introduce VAiRoma, a visual analytics system that couples state-of-the-art text analysis methods with an intuitive visual interface to help users make sense of events, places, times, and more importantly, the relationships between them. VAiRoma goes beyond textual content exploration, as it permits users to compare, make connections, and externalize the findings all within the visual interface. As a result, VAiRoma allows users to learn and create new knowledge regarding Roman history in an informed way. We evaluated VAiRoma with 16 participants through a user study, with the task being to learn about roman piazzas through finding relevant articles and new relationships. Our study results showed that the VAiRoma system enables the participants to find more relevant articles and connections compared to Web searches and literature search conducted in a roman library. Subjective feedback on VAiRoma was also very positive. In addition, we ran two case studies that demonstrate how VAiRoma can be used for deeper analysis, permitting the rapid discovery and analysis of a small number of key documents even when the original collection contains hundreds of thousands of documents.

Loucura imperial na Roma antiga

Directory of Open Access Journals (Sweden)

Aloys Winterling

2012-06-01

Full Text Available Este artigo aborda a questão da "loucura imperial" na Roma antiga, indagando-se sobre o que seria peculiar a ações de imperadores, como Calígula, Nero e Domiciano, que conduziu a conflitos com a aristocracia. Argumenta-se que apenas uma análise das estruturas e sistemas históricos do Alto Império possibilita explicar certos padrões de comportamento imperial, usualmente classificados como loucura pela historiografia dos séculos XIX e XX.

Los edificios deportivos de la Roma Antigua Sportive buildings in the ancient Rome

Directory of Open Access Journals (Sweden)

Angela TEJA

2013-09-01

Full Text Available La educación física y el deporte retrocedió —en la Roma antigua— respecto a los ideales físico-corporales griegos. Por contra, se fomentó una notable cultura de espectáculos y divertimentos, especialmente durante la época imperial. A fin de dar cobijo a los diversos espectáculos se construyeron en la ciudad de Roma —y por mimetismo en todas las urbes del Imperio— sofisticados edificios. En efecto, además de una importante red de circos —el más emblemático de los cuales fue el circo Máximo—, se levantaron anfiteatros y termas, amén del estadio de Dominiciano. La autora pasa revista a las distintas instalaciones «deportivas» de la Roma antigua, así como a los espectáculos que albergaban: las carreras del circo, los combates de gladiadores, las cacerías de fieras, las naumaquias, sin olvidar las competiciones del estadio y la pasión romana por las termas.Sport and physical education —in Ancient Rome-, looked back to the physical ideals of the Greeks. In contrast, there was also a specific encouragement of spectacles and performance or general entertainment during the Imperial Era. In order to cater for the diverse shows, sophisticated buildings were constructed in Rome, and reproduced in all the built-up areas throughout the Empire. In fact, besides the important circus network, the most emblematic of these being Maximo's Circus, amphitheatres, arenas and spa resorts were constructed, in addition to the Dominitian Stadium. The author studies the different types of «sporting» installations in Ancient Rome, considering the entertainments which took place in them: chariot races, gladiatorial combat, the hunting of wild beasts, naval combats, the stadium sports and, of course, the Roman passion for spas and hot baths.

Hartree-Fock study of the Anderson metal-insulator transition in the presence of Coulomb interaction: Two types of mobility edges and their multifractal scaling exponents

Science.gov (United States)

Lee, Hyun-Jung; Kim, Ki-Seok

2018-04-01

We investigate the role of Coulomb interaction in the multifractality of Anderson metal-insulator transition, where the Coulomb interaction is treated within the Hartree-Fock approximation, but disorder effects are taken into account exactly. An innovative technical aspect in our simulation is to utilize the Ewald-sum technique, which allows us to introduce the long-range nature of the Coulomb interaction into Hartree-Fock self-consistent equations of order parameters more accurately. This numerical simulation reproduces the Altshuler-Aronov correction in a metallic state and the Efros-Shklovskii pseudogap in an insulating phase, where the density of states ρ (ω ) is evaluated in three dimensions. Approaching the quantum critical point of a metal-insulator transition from either the metallic or insulting phase, we find that the density of states is given by ρ (ω ) ˜|ω| 1 /2 , which determines one critical exponent of the McMillan-Shklovskii scaling theory. Our main result is to evaluate the eigenfunction multifractal scaling exponent αq, given by the Legendre transformation of the fractal dimension τq, which characterizes the scaling behavior of the inverse participation ratio with respect to the system size L . Our multifractal analysis leads us to identify two kinds of mobility edges, one of which occurs near the Fermi energy and the other of which appears at a high energy, where the density of states at the Fermi energy shows the Coulomb-gap feature. We observe that the multifractal exponent at the high-energy mobility edge remains to be almost identical to that of the Anderson localization transition in the absence of Coulomb interactions. On the other hand, we find that the multifractal exponent near the Fermi energy is more enhanced than that at the high-energy mobility edge, suspected to result from interaction effects. However, both the multifractal exponents do not change even if the strength of the Coulomb interaction varies. We also show that the

Surface roughness and morphology of dental nanocomposites polished by four different procedures evaluated by a multifractal approach

Energy Technology Data Exchange (ETDEWEB)

Ţălu, Ştefan, E-mail: stefan_ta@yahoo.com [Technical University of Cluj-Napoca, Faculty of Mechanical Engineering, Department of AET, Discipline of Descriptive Geometry and Engineering Graphics, 103-105 B-dul Muncii St., Cluj-Napoca 400641, Cluj (Romania); Stach, Sebastian, E-mail: sebastian.stach@us.edu.pl [University of Silesia, Faculty of Computer Science and Materials Science, Institute of Informatics, Department of Biomedical Computer Systems, Będzińska 39, 41-205 Sosnowiec (Poland); Lainović, Tijana, E-mail: tijana.lainovic@gmail.com [University of Novi Sad, Faculty of Medicine, School of Dentistry, Hajduk Veljkova 3, 21000 Novi Sad (Serbia); Vilotić, Marko, E-mail: markovil@uns.ac.rs [University of Novi Sad, Faculty of Technical Sciences, Department for Production Engineering, Trg Dositeja Obradovića 6, 21000 Novi Sad (Serbia); Blažić, Larisa, E-mail: larisa.blazic@gmail.com [University of Novi Sad, Faculty of Medicine, School of Dentistry, Clinic of Dentistry of Vojvodina, Department of Restorative Dentistry and Endodontics, Hajduk Veljkova 3, 21000 Novi Sad (Serbia); Alb, Sandu Florin, E-mail: albflorin@yahoo.com [“Iuliu Haţieganu” University of Medicine and Pharmacy, Faculty of Dentistry, Department of Periodontology, 8 Victor Babeş St., 400012 Cluj-Napoca (Romania); Kakaš, Damir, E-mail: kakasdam@uns.ac.rs [University of Novi Sad, Faculty of Technical Sciences, Department for Production Engineering, Trg Dositeja Obradovića 6, 21000 Novi Sad (Serbia)

2015-03-01

Graphical abstract: - Highlights: • Multifractals are good indicators of polished dental composites 3-D surface structure. • The nanofilled composite had superior 3-D surface properties than the nanohybrid one. • Composite polishing with diamond paste created improved 3-D multifractal structure. • Recommendation: polish the composite with diamond paste if using the one-step tool. • Multifractal analysis could become essential in designing new dental surfaces. - Abstract: The objective of this study was to determine the effect of different dental polishing methods on surface texture parameters of dental nanocomposites. The 3-D surface morphology was investigated by atomic force microscopy (AFM) and multifractal analysis. Two representative dental resin-based nanocomposites were investigated: a nanofilled and a nanohybrid composite. The samples were polished by two dental polishing protocols using multi-step and one-step system. Both protocols were then followed by diamond paste polishing. The 3-D surface roughness of samples was studied by AFM on square areas of topography on the 80 × 80 μm{sup 2} scanning area. The multifractal spectrum theory based on computational algorithms was applied for AFM data and multifractal spectra were calculated. The generalized dimension D{sub q} and the singularity spectrum f(α) provided quantitative values that characterize the local scale properties of dental nanocomposites polished by four different dental polishing protocols at nanometer scale. The results showed that the larger the spectrum width Δα (Δα = α{sub max} − α{sub min}) of the multifractal spectra f(α), the more non-uniform was the surface morphology. Also, the 3-D surface topography was described by statistical parameters, according to ISO 25178-2:2012. The 3-D surface of samples had a multifractal nature. Nanofilled composite had lower values of height parameters than nanohybrid composites, due to its composition. Multi-step polishing protocol

Surface roughness and morphology of dental nanocomposites polished by four different procedures evaluated by a multifractal approach

International Nuclear Information System (INIS)

Ţălu, Ştefan; Stach, Sebastian; Lainović, Tijana; Vilotić, Marko; Blažić, Larisa; Alb, Sandu Florin; Kakaš, Damir

2015-01-01

Graphical abstract: - Highlights: • Multifractals are good indicators of polished dental composites 3-D surface structure. • The nanofilled composite had superior 3-D surface properties than the nanohybrid one. • Composite polishing with diamond paste created improved 3-D multifractal structure. • Recommendation: polish the composite with diamond paste if using the one-step tool. • Multifractal analysis could become essential in designing new dental surfaces. - Abstract: The objective of this study was to determine the effect of different dental polishing methods on surface texture parameters of dental nanocomposites. The 3-D surface morphology was investigated by atomic force microscopy (AFM) and multifractal analysis. Two representative dental resin-based nanocomposites were investigated: a nanofilled and a nanohybrid composite. The samples were polished by two dental polishing protocols using multi-step and one-step system. Both protocols were then followed by diamond paste polishing. The 3-D surface roughness of samples was studied by AFM on square areas of topography on the 80 × 80 μm 2 scanning area. The multifractal spectrum theory based on computational algorithms was applied for AFM data and multifractal spectra were calculated. The generalized dimension D q and the singularity spectrum f(α) provided quantitative values that characterize the local scale properties of dental nanocomposites polished by four different dental polishing protocols at nanometer scale. The results showed that the larger the spectrum width Δα (Δα = α max − α min ) of the multifractal spectra f(α), the more non-uniform was the surface morphology. Also, the 3-D surface topography was described by statistical parameters, according to ISO 25178-2:2012. The 3-D surface of samples had a multifractal nature. Nanofilled composite had lower values of height parameters than nanohybrid composites, due to its composition. Multi-step polishing protocol created a better

PageRank tracker: from ranking to tracking.

Science.gov (United States)

Gong, Chen; Fu, Keren; Loza, Artur; Wu, Qiang; Liu, Jia; Yang, Jie

2014-06-01

Video object tracking is widely used in many real-world applications, and it has been extensively studied for over two decades. However, tracking robustness is still an issue in most existing methods, due to the difficulties with adaptation to environmental or target changes. In order to improve adaptability, this paper formulates the tracking process as a ranking problem, and the PageRank algorithm, which is a well-known webpage ranking algorithm used by Google, is applied. Labeled and unlabeled samples in tracking application are analogous to query webpages and the webpages to be ranked, respectively. Therefore, determining the target is equivalent to finding the unlabeled sample that is the most associated with existing labeled set. We modify the conventional PageRank algorithm in three aspects for tracking application, including graph construction, PageRank vector acquisition and target filtering. Our simulations with the use of various challenging public-domain video sequences reveal that the proposed PageRank tracker outperforms mean-shift tracker, co-tracker, semiboosting and beyond semiboosting trackers in terms of accuracy, robustness and stability.

Fractional governing equations of transient groundwater flow in confined aquifers with multi-fractional dimensions in fractional time

Directory of Open Access Journals (Sweden)

M. L. Kavvas

2017-10-01

Full Text Available Using fractional calculus, a dimensionally consistent governing equation of transient, saturated groundwater flow in fractional time in a multi-fractional confined aquifer is developed. First, a dimensionally consistent continuity equation for transient saturated groundwater flow in fractional time and in a multi-fractional, multidimensional confined aquifer is developed. For the equation of water flux within a multi-fractional multidimensional confined aquifer, a dimensionally consistent equation is also developed. The governing equation of transient saturated groundwater flow in a multi-fractional, multidimensional confined aquifer in fractional time is then obtained by combining the fractional continuity and water flux equations. To illustrate the capability of the proposed governing equation of groundwater flow in a confined aquifer, a numerical application of the fractional governing equation to a confined aquifer groundwater flow problem was also performed.

Complexity and multifractality of neuronal noise in mouse and human hippocampal epileptiform dynamics

Science.gov (United States)

Serletis, Demitre; Bardakjian, Berj L.; Valiante, Taufik A.; Carlen, Peter L.

2012-10-01

Fractal methods offer an invaluable means of investigating turbulent nonlinearity in non-stationary biomedical recordings from the brain. Here, we investigate properties of complexity (i.e. the correlation dimension, maximum Lyapunov exponent, 1/fγ noise and approximate entropy) and multifractality in background neuronal noise-like activity underlying epileptiform transitions recorded at the intracellular and local network scales from two in vitro models: the whole-intact mouse hippocampus and lesional human hippocampal slices. Our results show evidence for reduced dynamical complexity and multifractal signal features following transition to the ictal epileptiform state. These findings suggest that pathological breakdown in multifractal complexity coincides with loss of signal variability or heterogeneity, consistent with an unhealthy ictal state that is far from the equilibrium of turbulent yet healthy fractal dynamics in the brain. Thus, it appears that background noise-like activity successfully captures complex and multifractal signal features that may, at least in part, be used to classify and identify brain state transitions in the healthy and epileptic brain, offering potential promise for therapeutic neuromodulatory strategies for afflicted patients suffering from epilepsy and other related neurological disorders. This paper is based on chapter 5 of Serletis (2010 PhD Dissertation Department of Physiology, Institute of Biomaterials and Biomedical Engineering, University of Toronto).

Multi-fractal analysis and lacunarity spectrum of the dark matter haloes in the SDSS-DR7

International Nuclear Information System (INIS)

Chacón-Cardona, C.A.; Casas-Miranda, R.A.; Muñoz-Cuartas, J.C.

2016-01-01

Highlights: • We analysed the dark matter in Seventh Data Release of the Sloan Digital Sky Survey. • From the initial sample with 412,468 galaxies, 339,505 dark matter haloes were used. • We found the multifractal and the lacunarity spectrum as radial distance function. • The dark matter set did not achieve at the physical dimension of the space. - Abstract: The dark matter halo distribution of the nearby universe is used to study the fractal behaviour in the proximate universe. The data, which is based on four volume-limited galaxy samples was obtained by Muñoz-Cuartas and Mueller (2012) from the Seventh Data Release of the Sloan Digital Sky Survey (SDSS-DR7). In order to know the fractal behaviour of the observed universe, from the initial sample which contains 412,468 galaxies and 339,505 dark matter haloes were used as input for the fractal calculations. Using this data we use the sliding-window technique for the dark matter distribution and compute the multi-fractal dimension and the lacunarity spectrum and use it to study its dependence on radial distance in every sample. The transition to homogeneity is not observed in the dark matter halo distribution obtained from the SDSS-DR7 volume-limited galaxy samples; in its place the dark matter halo distribution exhibits a persistent multi-fractal behaviour where the measured dimension does not arrive at the value of the physical dimension of the space, for all structure parameter values of the analysed set, at least up to radial distances of the ordered from 165 Mpc/h from the available centres of each sample. Our results and their implications are discussed in the context of the formation of large-scale structures in the universe.

Universality of rank-ordering distributions in the arts and sciences.

Directory of Open Access Journals (Sweden)

Gustavo Martínez-Mekler

Full Text Available Searching for generic behaviors has been one of the driving forces leading to a deep understanding and classification of diverse phenomena. Usually a starting point is the development of a phenomenology based on observations. Such is the case for power law distributions encountered in a wealth of situations coming from physics, geophysics, biology, lexicography as well as social and financial networks. This finding is however restricted to a range of values outside of which finite size corrections are often invoked. Here we uncover a universal behavior of the way in which elements of a system are distributed according to their rank with respect to a given property, valid for the full range of values, regardless of whether or not a power law has previously been suggested. We propose a two parameter functional form for these rank-ordered distributions that gives excellent fits to an impressive amount of very diverse phenomena, coming from the arts, social and natural sciences. It is a discrete version of a generalized beta distribution, given by f(r = A(N+1-r(b/r(a, where r is the rank, N its maximum value, A the normalization constant and (a, b two fitting exponents. Prompted by our genetic sequence observations we present a growth probabilistic model incorporating mutation-duplication features that generates data complying with this distribution. The competition between permanence and change appears to be a relevant, though not necessary feature. Additionally, our observations mainly of social phenomena suggest that a multifactorial quality resulting from the convergence of several heterogeneous underlying processes is an important feature. We also explore the significance of the distribution parameters and their classifying potential. The ubiquity of our findings suggests that there must be a fundamental underlying explanation, most probably of a statistical nature, such as an appropriate central limit theorem formulation.

Nonlinear temperature effects on multifractal complexity of metabolic rate of mice

Directory of Open Access Journals (Sweden)

Fabio A. Labra

2016-10-01

Full Text Available Complex physiological dynamics have been argued to be a signature of healthy physiological function. Here we test whether the complexity of metabolic rate fluctuations in small endotherms decreases with lower environmental temperatures. To do so, we examine the multifractal temporal scaling properties of the rate of change in oxygen consumption r(VO2, in the laboratory mouse Mus musculus, assessing their long range correlation properties across seven different environmental temperatures, ranging from 0 °C to 30 °C. To do so, we applied multifractal detrended fluctuation analysis (MF-DFA, finding that r(VO2 fluctuations show two scaling regimes. For small time scales below the crossover time (approximately 102 s, either monofractal or weak multifractal dynamics are observed depending on whether Ta  15 °C respectively. For larger time scales, r(VO2 fluctuations are characterized by an asymptotic scaling exponent that indicates multifractal anti-persistent or uncorrelated dynamics. For both scaling regimes, a generalization of the multiplicative cascade model provides very good fits for the Renyi exponents τ(q, showing that the infinite number of exponents h(q can be described by only two independent parameters, a and b. We also show that the long-range correlation structure of r(VO2 time series differs from randomly shuffled series, and may not be explained as an artifact of stochastic sampling of a linear frequency spectrum. These results show that metabolic rate dynamics in a well studied micro-endotherm are consistent with a highly non-linear feedback control system.

Geovisualización del turismo urbano. Roma

Directory of Open Access Journals (Sweden)

Fabien Girardin

2008-11-01

Este trabajo, presenta la oportunidad emergente que supone el uso y práctica de geo-visualizaciones que permiten revelar el "pulso de una ciudad" con la visualización de los datos espacio-temporales generados gracias a la interacción de las personas con el entorno urbano, para lo cual se georreferencian algunos fenómenos en la ciudad de Roma.

Multifractal analysis of CoFe2O4/2DBS/H2O ferrofluid from TEM and SANS measurements

International Nuclear Information System (INIS)

Stan, C.; Cristescu, C.P.; Balasoiu, M.; Ivankov, O.I.

2015-01-01

Preliminary investigation on the morphological properties and the multifractal characteristics of CoFe 2 O 4 nanoparticles, coated with a double layer of dodecylbenzenesulphonic acid and dispersed in double distillated water, is presented. TEM images of the sample are analyzed and the computed multifractal spectrum reveals universal multifractality. A comparison with the fractal approach applied to SANS data is presented, and consistency of results is demonstrated.

Influence of the atomic force microscope tip on the multifractal analysis of rough surfaces

International Nuclear Information System (INIS)

Klapetek, Petr; Ohlidal, Ivan; Bilek, Jindrich

2004-01-01

In this paper, the influence of atomic force microscope tip on the multifractal analysis of rough surfaces is discussed. This analysis is based on two methods, i.e. on the correlation function method and the wavelet transform modulus maxima method. The principles of both methods are briefly described. Both methods are applied to simulated rough surfaces (simulation is performed by the spectral synthesis method). It is shown that the finite dimensions of the microscope tip misrepresent the values of the quantities expressing the multifractal analysis of rough surfaces within both the methods. Thus, it was concretely shown that the influence of the finite dimensions of the microscope tip changed mono-fractal properties of simulated rough surface to multifractal ones. Further, it is shown that a surface reconstruction method developed for removing the negative influence of the microscope tip does not improve the results obtained in a substantial way. The theoretical procedures concerning both the methods, i.e. the correlation function method and the wavelet transform modulus maxima method, are illustrated for the multifractal analysis of randomly rough gallium arsenide surfaces prepared by means of the thermal oxidation of smooth gallium arsenide surfaces and subsequent dissolution of the oxide films

MULTIFRACTAL SOLAR EUV INTENSITY FLUCTUATIONS AND THEIR IMPLICATIONS FOR CORONAL HEATING MODELS

Energy Technology Data Exchange (ETDEWEB)

Cadavid, A. C.; Lawrence, J. K.; Christian, D. J. [Department of Physics and Astronomy, California State University Northridge, 18111 Nordhoff Street, Northridge, CA 91330 (United States); Rivera, Y. J. [Department of Climate and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143 (United States); Jennings, P. J. [5174 S. Slauson Avenue, Culver City, CA 90230 (United States); Rappazzo, A. F., E-mail: ana.cadavid@csun.edu [Department of Earth, Planetary and Space Sciences, University of California Los Angeles, Los Angeles, CA 90095 (United States)

2016-11-10

We investigate the scaling properties of the long-range temporal evolution and intermittency of Atmospheric Imaging Assembly/ Solar Dynamics Observatory intensity observations in four solar environments: an active region core, a weak emission region, and two core loops. We use two approaches: the probability distribution function (PDF) of time series increments and multifractal detrended fluctuation analysis (MF-DFA). Noise taints the results, so we focus on the 171 Å waveband, which has the highest signal-to-noise ratio. The lags between pairs of wavebands distinguish between coronal versus transition region (TR) emission. In all physical regions studied, scaling in the range of 15–45 minutes is multifractal, and the time series are anti-persistent on average. The degree of anti-correlation in the TR time series is greater than that for coronal emission. The multifractality stems from long-term correlations in the data rather than the wide distribution of intensities. Observations in the 335 Å waveband can be described in terms of a multifractal with added noise. The multiscaling of the extreme-ultraviolet data agrees qualitatively with the radiance from a phenomenological model of impulsive bursts plus noise, and also from ohmic dissipation in a reduced magnetohydrodynamic model for coronal loop heating. The parameter space must be further explored to seek quantitative agreement. Thus, the observational “signatures” obtained by the combined tests of the PDF of increments and the MF-DFA offer strong constraints that can systematically discriminate among models for coronal heating.

Multifractal characteristics of NDVI maps in space and time in the Community of Madrid (Spain)

Science.gov (United States)

Sotoca, Juan J. Martin; Saa-Requejo, Antonio; Grau, Juan B.; Tarquis, Ana M.

2015-04-01

Satellite information has contributed to improve our understanding of the spatial variability of hydro-climatic and ecological processes. Vegetation activity is tightly coupled with climate, hydro-ecological fluxes, and terrain dynamics in river basins at a wide range of space-time scales (Scheuring and Riedi, 1994). Indices of vegetation activity are constructed using satellite information of reflectance of the relevant spectral bands which enhance the contribution of vegetation being Normalized Difference Vegetation Index (NDVI) widely used. How can we study such a complex system? Multifractals and fractals are related techniques mainly used in physics to characterize the scaling behaviour of a system; they differ in that fractals look at the geometry of presence/absence patterns, while multifractals look at the arrangement of quantities such as population or biomass densities (Saravia et al., 2012). Scaling laws are an emergent general feature of ecological systems; they reflect constraints in their organization that can provide tracks about the underlying mechanisms (Solé and Bascompte, 2006). In this work, we have applied these techniques to study the spatial pattern through one year of NDVI maps. A rectangular area that includes the Community of Madrid and part of the surroundings, consisting of 300 x 280 pixels with a resolution of 500 x 500 m2 has been selected and monthly NDVI maps analyzed using the multifractal spectrum and the map of singularities (Cheng and Agterberg, 1996). The results show a cyclical pattern in the multifractal behaviour and singularity points related to river basin networks (Martín-Sotoca, 2014). References Cheng, Q. and Agterberg, F.P. (1996). Multifractal modeling and spatial statistics. Math. Geol. Vol 28, 1-16. Martín-Sotoca, J.J. (2014) Estructura Espacial de la Sequía en Pastos y sus Aplicaciones en el Seguro Agrario. Master Thesis, UPM (In Spanish). Saravia LA, Giorgi A, Momo F.: Multifractal growth in periphyton

Culture and the school: The degree of educational integration of Roma and Gypsies in the Peloponnese region of Greece

Science.gov (United States)

Kiprianos, Pandelis; Daskalaki, Ivi; Stamelos, Georgios B.

2012-10-01

This article examines the degree of integration of Roma and Gypsy children in formal education in the Peloponnese region of Greece. It is based on field research conducted by the University of Patras during the school year 2006/07 within the framework of the Greek Ministry of Education's "Integration of Roma children in school" programme, funded by the European Union. Despite governmental incentives for poor families to enrol their school-aged children, school attendance of Roma and Gypsy children was found to decline from primary year one to primary year six, with hardly any of them entering secondary school at all. Besides looking at school attendance figures and Roma and Gypsy children's proficiency in reading, writing and numeracy, this paper also considers gender, family composition, living conditions and economic situation, as well as culturally constructed perceptions of childhood and a person's life cycle. The aim of this article is to highlight the contradictions and ambiguities involved in the process of incorporating Roma and Gypsy children in formal education, and to evaluate their school performance and assess their academic choices.

To be and not to be: scale correlations in random multifractal processes

DEFF Research Database (Denmark)

Cleve, Jochen; Schmiegel, Jürgen; Greiner, Martin

We discuss various properties of a random multifractal process, which are related to the issue of scale correlations. By design, the process is homogeneous, non-conservative and has no built-in scale correlations. However, when it comes to observables like breakdown coefficients, which are based...... on a coarse-graining of the multifractal field, scale correlations do appear. In the log-normal limit of the model process, the conditional distributions and moments of breakdown coefficients reproduce the observations made in fully developed small-scale turbulence. These findings help to understand several...

Shaping the Right to Education for Roma Children: A Case Study of Present Practices in Ghent, Belgium

Science.gov (United States)

Hemelsoet, Elias

2015-01-01

Western European cities are increasingly confronted with Roma immigrants. Societal changes associated with this phenomenon create new challenges for schools. Using a case study, this article sheds light on present practices that shape the right to education for Roma children. Three principal success factors are distinguished: boundary-blurring…

An empirical test of self-control theory in Roma adolescents

Czech Academy of Sciences Publication Activity Database

Vazsonyi, A. T.; Ksinan Jiskrova, G.; Ksinan, A. J.; Blatný, Marek

2016-01-01

Roč. 44, March 01 (2016), s. 66-76 ISSN 0047-2352 Institutional support: RVO:68081740 Keywords : Roma * Romani * Self-control * Cross-cultural * Deviance * Parenting Subject RIV: AN - Psychology Impact factor: 2.339, year: 2016

Multifractal detrended Cross Correlation Analysis of Foreign Exchange and SENSEX fluctuation in Indian perspective

Science.gov (United States)

Dutta, Srimonti; Ghosh, Dipak; Chatterjee, Sucharita

2016-12-01

The manuscript studies autocorrelation and cross correlation of SENSEX fluctuations and Forex Exchange Rate in respect to Indian scenario. Multifractal detrended fluctuation analysis (MFDFA) and multifractal detrended cross correlation analysis (MFDXA) were employed to study the correlation between the two series. It was observed that the two series are strongly cross correlated. The change of degree of cross correlation with time was studied and the results are interpreted qualitatively.

Giuseppe Cafiero sulle orme di Joyce a Roma

Directory of Open Access Journals (Sweden)

Carla De Petris

2011-08-01

Full Text Available In 2006 Giuseppe Cafiero published James Joyce, Roma & altre storie, a novel with thriller-like undertones that weaves stories around the author of Ulysses. In her conversation with the author, Carla de Petris investigates the genesis of the novel and reflects on the post-modernist stances of its complex plot.

Power constellations between Roma pupils and their teachers

Directory of Open Access Journals (Sweden)

Iveta Rožníčková

2017-11-01

Full Text Available The goal of this empirical study is to describe power constellations that are generated in interactions between Roma pupils and their teachers, and also to summarize the basic findings of this research and to point out some real situations that can occur during the teaching lessons. The first part of the thesis describes the differences in the social interaction of Roma pupils. The second part is focused on the authority of the teachers and also on using this authority during the lessons. The third part is focused on pupils‘ strategies that are created based on the requirements of teachers. The basic findings of the research are selected in the methodological section. The research survey revealed five power constellations, which are the subject of this empirical study. The empirical study suggests how teachers and pupils define and shape relationships. From the present paper, a lot of influences are involved in the formation of power constellation, ranging from the personality of the teachers, socializing in school, through family upbringing to cultural differences.

Il cielo sopra Roma I luoghi dell’astronomia

CERN Document Server

Buonanno, Roberto

2008-01-01

L’astronomia a Roma c’è sempre stata, ma un po’ nascosta: era nei palazzi, nelle chiese o, meglio, sopra le chiese, specole disseminate lungo un percorso che oramai conoscono in pochi. I romani hanno assistito, incuriositi ed impauriti, al rogo di Giordano Bruno in un angolo di Campo de' Fiori a loro familiare, ma probabilmente non capirono bene di quale colpa fosse accusato. Non pensarono certo che si trattasse di un filosofo e di uno scienziato che aveva cercato di immaginare in che modo era fatto il mondo. Chi era questo Galileo, di cui si celebrava il processo a S. Maria sopra Minerva? Era un uomo che voleva cambiare la prospettiva del mondo e che, per questo, era stato ammonito da Roberto Bellarmino. E chi era questo gesuita, Secchi, che nel 1870 costringeva gli Italiani a privare Roma del suo Osservatorio Astronomico, visto che il Direttore non riconosceva lo Stato Italiano? Come è possibile che dopo la visita di Hitler a Mussolini alla vigilia della Guerra, la Germania decise di regalare all’...

Comparison of the multifractal characteristics of heavy metals in soils within two areas of contrasting economic activities in China

Science.gov (United States)

Li, Xiaohui; Li, Xiangling; Yuan, Feng; Jowitt, Simon M.; Zhou, Taofa; Yang, Kui; Zhou, Jie; Hu, Xunyu; Li, Yang

2016-09-01

Industrial and agricultural activities can generate heavy metal pollution that can cause a number of negative environmental and health impacts. This means that evaluating heavy metal pollution and identifying the sources of these pollutants, especially in urban or developed areas, is an important first step in mitigating the effects of these contaminating but necessary economic activities. Here, we present the results of a heavy metal (Cu, Pb, Zn, Cd, As, and Hg) soil geochemical survey in Hefei city. We used a multifractal spectral technique to identify and compare the multifractality of heavy metal concentrations of soils within the industrial Daxing and agricultural Yicheng areas. This paper uses three multifractal parameters (Δα, Δf(α), and τ''(1)) to indicate the overall amount of multifractality within the soil geochemical data. The results show all of the elements barring Hg have larger Δα, Δf(α), and τ''(1) values in the Daxing area compared to the Yicheng area. The degree of multifractality suggests that the differing economic activities in Daxing and Yicheng generate very different heavy metal pollution loads. In addition, the industrial Daxing area contains significant Pb and Cd soil contamination, whereas Hg is the main heavy metal present in soils within the Yicheng area, indicating that differing clean-up procedures and approaches to remediating these polluted areas are needed. The results also indicate that multifractal modelling and the associated generation of multifractal parameters can be a useful approach in the evaluation of heavy metal pollution in soils.

Ethical issues in communication of diagnosis and end-of-life decision-making process in some of the Romanian Roma communities.

Science.gov (United States)

Roman, Gabriel; Enache, Angela; Pârvu, Andrada; Gramma, Rodica; Moisa, Ştefana Maria; Dumitraş, Silvia; Ioan, Beatrice

2013-08-01

Medical communication in Western-oriented countries is dominated by concepts of shared decision-making and patient autonomy. In interactions with Roma patients, these behavioral patterns rarely seem to be achieved because the culture and ethnicity have often been shown as barriers in establishing an effective and satisfying doctor-patient relationship. The study aims to explore the Roma's beliefs and experiences related to autonomy and decision-making process in the case of a disease with poor prognosis. Forty-eight Roma people from two Romanian counties participated in semi-structured interviews, conducted by a research team from the University of Medicine and Pharmacy of Iasi. Participants were recruited among the chronically ill patients and caregivers. The Roma community opposes informing the terminal patients about their condition, the "silence conspiracy" being widely practiced. The family fully undertakes the right of decision making, thus minimizing the patient's autonomy. We identified ethical dilemmas concerning autonomy, lack of patients' real decision-making power, and paternalistic attitudes exerted firstly by the family and, on demand, by the physician. Instead, the Roma patient benefits from a very active support network, being accompanied at the hospital by numerous relatives. The patient's right to make autonomous decisions promoted in the Western countries and stipulated by the Romanian law has diminished value in the Roma community. For the Roma, the understanding of dignity is not simply individual and personal, but it is closely related to their cultural particularities. Ignoring their cultural values could create conflicts between healthcare providers and community.

The Identity of Czech Deaf Roma

OpenAIRE

Kalousová, Josefina

2012-01-01

With the definition of Deaf people as a cultural and linguistic minority the research of Deaf identity became possible. Following this, questions of identity of minority deaf persons emerged. Do these persons affiliate to the Deaf community or to their ethnic minority? This bachelor thesis focuses on the topic of Czech deaf Roma identity. The underlying assumption of the paper is that identity is a continuing process dependent on the interaction of an individual and society and that it consti...

Multifractal modeling of the production of concentrated sugar syrup crystal

International Nuclear Information System (INIS)

Bi Sheng; Gao Jianbo

2016-01-01

High quality, concentrated sugar syrup crystal is produced in a critical step in cane sugar production: the clarification process. It is characterized by two variables: the color of the produced sugar and its clarity degree. We show that the temporal variations of these variables follow power-law distributions and can be well modeled by multiplicative cascade multifractal processes. These interesting properties suggest that the degradation in color and clarity degree has a system-wide cause. In particular, the cascade multifractal model suggests that the degradation in color and clarity degree can be equivalently accounted for by the initial “impurities” in the sugarcane. Hence, more effective cleaning of the sugarcane before the clarification stage may lead to substantial improvement in the effect of clarification. (paper)

Voices on Italy’s Recent History: Aulò: Roma postcoloniale and La quarta via

Directory of Open Access Journals (Sweden)

Linde Luijnenburg

2013-07-01

Full Text Available Recensione di:Simone Brioni (ed., Somalitalia: Quattro Vie per Mogadiscio/Somalitalia: Four Roads to Mogadishu. With the documentary La quarta via: Mogadiscio, Pavia. Roma, Kimerafilm,2012, 37 p., ISBN: 9788890771408. € 15,00.Ribka Sibhatu, Aulò! Aulò! Aulò! Poesie di nostalgia, d’esilio ed’amore. Aulò! Aulò! Aulò! Poems of Nostalgia, Exile and Love.With the documentary by Simone Brioni (ed. Aulò: Romapostcoloniale, Roma, Kimerafilm, 2012, 41 p., ISBN:9788890771415. € 15,00.

Multifractal Analysis of Seismically Induced Soft-Sediment Deformation Structures Imaged by X-Ray Computed Tomography

Science.gov (United States)

Nakashima, Yoshito; Komatsubara, Junko

Unconsolidated soft sediments deform and mix complexly by seismically induced fluidization. Such geological soft-sediment deformation structures (SSDSs) recorded in boring cores were imaged by X-ray computed tomography (CT), which enables visualization of the inhomogeneous spatial distribution of iron-bearing mineral grains as strong X-ray absorbers in the deformed strata. Multifractal analysis was applied to the two-dimensional (2D) CT images with various degrees of deformation and mixing. The results show that the distribution of the iron-bearing mineral grains is multifractal for less deformed/mixed strata and almost monofractal for fully mixed (i.e. almost homogenized) strata. Computer simulations of deformation of real and synthetic digital images were performed using the egg-beater flow model. The simulations successfully reproduced the transformation from the multifractal spectra into almost monofractal spectra (i.e. almost convergence on a single point) with an increase in deformation/mixing intensity. The present study demonstrates that multifractal analysis coupled with X-ray CT and the mixing flow model is useful to quantify the complexity of seismically induced SSDSs, standing as a novel method for the evaluation of cores for seismic risk assessment.

Multifractal temporally weighted detrended cross-correlation analysis to quantify power-law cross-correlation and its application to stock markets

Science.gov (United States)

Wei, Yun-Lan; Yu, Zu-Guo; Zou, Hai-Long; Anh, Vo

2017-06-01

A new method—multifractal temporally weighted detrended cross-correlation analysis (MF-TWXDFA)—is proposed to investigate multifractal cross-correlations in this paper. This new method is based on multifractal temporally weighted detrended fluctuation analysis and multifractal cross-correlation analysis (MFCCA). An innovation of the method is applying geographically weighted regression to estimate local trends in the nonstationary time series. We also take into consideration the sign of the fluctuations in computing the corresponding detrended cross-covariance function. To test the performance of the MF-TWXDFA algorithm, we apply it and the MFCCA method on simulated and actual series. Numerical tests on artificially simulated series demonstrate that our method can accurately detect long-range cross-correlations for two simultaneously recorded series. To further show the utility of MF-TWXDFA, we apply it on time series from stock markets and find that power-law cross-correlation between stock returns is significantly multifractal. A new coefficient, MF-TWXDFA cross-correlation coefficient, is also defined to quantify the levels of cross-correlation between two time series.

HIV and selected blood-borne and sexually transmitted infections in a predominantly Roma (Gypsy) neighbourhood in Budapest, Hungary

Science.gov (United States)

Gyarmathy, V. Anna; Ujhelyi, Eszter; Neaigus, Alan

2008-01-01

We assessed the prevalence of HIV and selected blood-borne and sexually transmitted infections among a convenience sample of 64 residents of Dzsumbuj, a predominantly Roma (Gypsy) neighbourhood in Budapest, Hungary. No cases of HIV were detected, while the prevalence of Hepatitis B infection (anti-HBc) was 27% and syphilis prevalence was 2%. Romas (n=50) were significantly more likely than non-Romas (n=14) to have HAV antibodies (80% vs. 43%) and less likely to be HBV immunized (anti-HBs only; 6% vs. 29%). Current drug injectors (n=13) were more likely than non-injectors (n=51) to have antibodies against HAV (85% vs. 69%) and HCV (85% vs. 8%). While HIV has not been introduced in this population, risk conditions for a potentially explosive HIV epidemic are present. Health care policies should focus on expanding coverage for HAV and HBV immunizations, and access to HIV preventive services needs to be extended to marginalized, mostly minority populations, such as the Roma in Europe. PMID:18935777

Order-disorder transition in conflicting dynamics leading to rank-frequency generalized beta distributions

Science.gov (United States)

Alvarez-Martinez, R.; Martinez-Mekler, G.; Cocho, G.

2011-01-01

The behavior of rank-ordered distributions of phenomena present in a variety of fields such as biology, sociology, linguistics, finance and geophysics has been a matter of intense research. Often power laws have been encountered; however, their validity tends to hold mainly for an intermediate range of rank values. In a recent publication (Martínez-Mekler et al., 2009 [7]), a generalization of the functional form of the beta distribution has been shown to give excellent fits for many systems of very diverse nature, valid for the whole range of rank values, regardless of whether or not a power law behavior has been previously suggested. Here we give some insight on the significance of the two free parameters which appear as exponents in the functional form, by looking into discrete probabilistic branching processes with conflicting dynamics. We analyze a variety of realizations of these so-called expansion-modification models first introduced by Wentian Li (1989) [10]. We focus our attention on an order-disorder transition we encounter as we vary the modification probability p. We characterize this transition by means of the fitting parameters. Our numerical studies show that one of the fitting exponents is related to the presence of long-range correlations exhibited by power spectrum scale invariance, while the other registers the effect of disordering elements leading to a breakdown of these properties. In the absence of long-range correlations, this parameter is sensitive to the occurrence of unlikely events. We also introduce an approximate calculation scheme that relates this dynamics to multinomial multiplicative processes. A better understanding through these models of the meaning of the generalized beta-fitting exponents may contribute to their potential for identifying and characterizing universality classes.

Comparative Multifractal Detrended Fluctuation Analysis of Heavy Ion Interactions at a Few GeV to a Few Hundred GeV

Directory of Open Access Journals (Sweden)

Gopa Bhoumik

2016-01-01

Full Text Available We have studied the multifractality of pion emission process in 16O-AgBr interactions at 2.1 AGeV  and  60 AGeV, 12C-AgBr  and  24Mg-AgBr interactions at 4.5 AGeV, and 32S-AgBr interactions at 200 AGeV using Multifractal Detrended Fluctuation Analysis (MFDFA method which is capable of extracting the actual multifractal property filtering out the average trend of fluctuation. The analysis reveals that the pseudorapidity distribution of the shower particles is multifractal in nature for all the interactions; that is, pion production mechanism has inbuilt multiscale self-similarity property. We have employed MFDFA method for randomly generated events for 32S-AgBr interactions at 200 AGeV. Comparison of expt. results with those obtained from randomly generated data set reveals that the source of multifractality in our data is the presence of long range correlation. Comparing the results obtained from different interactions, it may be concluded that strength of multifractality decreases with projectile mass for the same projectile energy and for a particular projectile it increases with energy. The values of ordinary Hurst exponent suggest that there is long range correlation present in our data for all the interactions.

Study on multi-fractal fault diagnosis based on EMD fusion in hydraulic engineering

International Nuclear Information System (INIS)

Lu, Shibao; Wang, Jianhua; Xue, Yangang

2016-01-01

Highlights: • The measured shafting vibration data signal of the hydroelectric generating set is acquired through EMD. • The vibration signal waveform is identified and purified with EMD to obtain approximation coefficient of various fault signals. • The multi-fractal spectrum provides the distributed geometrical or probabilistic information of point. • EMD provides the real information for the next subsequent analysis and recognition. - Abstract: The vibration signal analysis of the hydraulic turbine unit aims at extracting the characteristic information of the unit vibration. The effective signal processing and information extraction are the key to state monitoring and fault diagnosis of the hydraulic turbine unit. In this paper, the vibration fault diagnosis model is established, which combines EMD, multi-fractal spectrum and modified BP neural network; the vibration signal waveform is identified and purified with EMD to obtain approximation coefficient of various fault signals; the characteristic vector of the vibration fault is acquired with the multi-fractal spectrum algorithm, which is classified and identified as input vector of BP neural network. The signal characteristics are extracted through the waveform, the diagnosis and identification are carried out in combination of the multi-fractal spectrum to provide a new method for fault diagnosis of the hydraulic turbine unit. After the application test, the results show that the method can improve the intelligence and humanization of diagnosis, enhance the man–machine interaction, and produce satisfactory identification result.

Characterizing water fingering phenomena in soils using magnetic resonance imaging and multifractal theory

Directory of Open Access Journals (Sweden)

A. Posadas

2009-02-01

Full Text Available The study of water movement in soils is of fundamental importance in hydrologic science. It is generally accepted that in most soils, water and solutes flow through unsaturated zones via preferential paths or fingers. This paper combines magnetic resonance imaging (MRI with both fractal and multifractal theory to characterize preferential flow in three dimensions. A cubic double-layer column filled with fine and coarse textured sand was placed into a 500 gauss MRI system. Water infiltration through the column (0.15×0.15×0.15 m³ was recorded in steady state conditions. Twelve sections with a voxel volume of 0.1×0.1×10 mm³ each were obtained and characterized using fractal and multifractal theory. The MRI system provided a detailed description of the preferential flow under steady state conditions and was also useful in understanding the dynamics of the formation of the fingers. The f(α multifractal spectrum was very sensitive to the variation encountered at each horizontally-oriented slice of the column and provided a suitable characterization of the dynamics of the process identifying four spatial domains. In conclusion, MRI and fractal and multifractal analysis were able to characterize and describe the preferential flow process in soils. Used together, the two methods provide a good alternative to study flow transport phenomena in soils and in porous media.

Multifractal analysis of electronic transitions in a family of quasiperiodic potentials

International Nuclear Information System (INIS)

Thakur, P.K.; Brouers, F.; Ananthakrishna, G.

1989-12-01

We analyze the nature of extended, localized and critical states in an extension of the Aubry model where mobility edges have been reported. We calculate the multifractal spectra of exact eigenstates of this model for varying chain lengths and confirm the existence of mobility edges. Moreover we are able to show that the localized states can exhibit a behaviour rather different from the usual exponentially decaying states in a random potential. Lyapounov exponents or participation ratios are unable to produce such information. Our results also indicate that a stable multifractal distribution is a general feature of crossovers of states of different nature. This conjecture should be confirmed in other models. (author). 17 refs, 8 figs

Multifractal detrended cross-correlation between the Chinese domestic and international gold markets based on DCCA and DMCA methods

Science.gov (United States)

Cao, Guangxi; Han, Yan; Chen, Yuemeng; Yang, Chunxia

2014-05-01

Based on the daily price data of Shanghai and London gold spot markets, we applied detrended cross-correlation analysis (DCCA) and detrended moving average cross-correlation analysis (DMCA) methods to quantify power-law cross-correlation between domestic and international gold markets. Results show that the cross-correlations between the Chinese domestic and international gold spot markets are multifractal. Furthermore, forward DMCA and backward DMCA seems to outperform DCCA and centered DMCA for short-range gold series, which confirms the comparison results of short-range artificial data in L. Y. He and S. P. Chen [Physica A 390 (2011) 3806-3814]. Finally, we analyzed the local multifractal characteristics of the cross-correlation between Chinese domestic and international gold markets. We show that multifractal characteristics of the cross-correlation between the Chinese domestic and international gold markets are time-varying and that multifractal characteristics were strengthened by the financial crisis in 2007-2008.

Multifractal properties of ball milling dynamics

Energy Technology Data Exchange (ETDEWEB)

Budroni, M. A., E-mail: mabudroni@uniss.it; Pilosu, V.; Rustici, M. [Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, Via Vienna 2, Sassari 07100 (Italy); Delogu, F. [Dipartimento di Ingegneria Meccanica, Chimica, e dei Materiali, Università degli Studi di Cagliari, via Marengo 2, Cagliari 09123 (Italy)

2014-06-15

This work focuses on the dynamics of a ball inside the reactor of a ball mill. We show that the distribution of collisions at the reactor walls exhibits multifractal properties in a wide region of the parameter space defining the geometrical characteristics of the reactor and the collision elasticity. This feature points to the presence of restricted self-organized zones of the reactor walls where the ball preferentially collides and the mechanical energy is mainly dissipated.

Roma e a questão geográfica.

OpenAIRE

Gonçalves, Jussemar Weiss

2008-01-01

Este artigo trata da relação entre Geografia e História a partir do estudo das origens da cidade de Roma. Isto mostra-nos de uma forma clara que a questão do território só adquire importância quando relacionada a outros fatores.

Predictors of medication use in the Roma population in Spain: a population-based national study.

Science.gov (United States)

Martín-Pérez, M; Hernández Barrera, V; López de Andrés, A; Jiménez-Trujillo, I; Jiménez-García, R; Carrasco-Garrido, P

2015-05-01

To describe the prevalence of prescribed and self-medicated use of medication in the Spanish Roma population, and identify the associated factors. Descriptive cross-sectional study. Data from the first National Health Survey conducted on the Roma population in Spain were used. The sample comprised 1000 Spanish Roma adults of both sexes aged ≥16 years. Answers (yes/no) to the question, 'In the last two weeks have you taken the following medicines [in reference to a list of medicines that might be used by the population] and were they prescribed for you by a doctor?' were used to ascertain 'medication use'. 'Self-medication' referred to use of these medicines without medical prescription. Using multivariate logistic regression models, odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to identify associated factors. The overall prevalence of medication use in the Roma population for both sexes was 69.1%, and 38.7% was self-medicated. Females reported higher use of medication than males (75.1% vs 62.3%); however, self-medication was higher among males. Analgesics and antipyretics were used most often (35.8%). Among males, the variables that were independently and significantly associated with a higher probability of medication use were: age; negative perception of health; presence of chronic disease (OR 2.81; 95% CI 1.67-4.73); and medical visits (OR 4.51; 95% CI 2.54-8.01). The variables were the same among females, except for age. A high percentage of the Spanish Roma population use medication, and a significant proportion of them self-medicate. The presence of chronic diseases, a negative perception of health and medical consultations were associated with increased use of medication in the study population. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Understanding the source of multifractality in financial markets

Czech Academy of Sciences Publication Activity Database

Baruník, Jozef; Aste, T.; Di Matteo, T.; Liu, R.

2012-01-01

Roč. 391, č. 17 (2012), s. 4234-4251 ISSN 0378-4371 R&D Projects: GA ČR GA402/09/0965 Institutional research plan: CEZ:AV0Z10750506 Keywords : Multifractality * Financial markets * Hurst exponent Subject RIV: AH - Economics Impact factor: 1.676, year: 2012 http://www.sciencedirect.com/science/article/pii/S0378437112002890

Concept City: Roma ri-vista e vissuta ne La dolce vita e La grande bellezza

OpenAIRE

Martini, Alessia

2015-01-01

A partire dagli anni del neorealismo, Roma è stata una location particolarmente amata dai registi italiani che hanno utilizzato con finalità simboliche diversi luoghi della città—dalle borgate ai monumenti del centro—al fine di raccontare un preciso momento storico e una precisa situazione sociale. In questo articolo prenderò in considerazione due film ambientati a Roma, La dolce vita di Federico Fellini (1960) e La grande bellezza di Paolo Sorrentino (2013), per analizzare le valenze che la ...

La Dea Roma de Segóbriga

Directory of Open Access Journals (Sweden)

Martín ALMAGRO-GORBEA

2009-12-01

Full Text Available Una hermosa escultura romana a la que hemos creído podríamos llamar desde ahora la «Dea Roma de Segóbriga», realizada en mármol blanco. Ahora ofrece una acusada pátina de color hueso. Mide 1,95 m. de altura, 0,69 de anchura máxima y 0,54 de grueso en su parte más voluminosa. Se conserva en el Museo de Cuenca.

Questioning Inclusion: The Education of Roma/Traveller Students and Young People in Europe and England--A Critical Examination

Science.gov (United States)

Themelis, Spyros

2009-01-01

This article deals with issues pertinent to the "inclusion" of Roma/Traveller children and young people in Europe and, in particular, England. It discusses some key issues that pertain to the inclusion of Roma/Traveller groups in society and it critically presents some key policies that have been advanced to tackle educational and social…

Roma e a questão geográfica

Directory of Open Access Journals (Sweden)

Jussemar Weiss Gonçalves

2005-01-01

Full Text Available Este artigo trata da relação entre Geografia e História a partir do estudo das origens da cidade de Roma. Isto mostra-nos de uma forma clara que a questão do território só adquire importância quando relacionada a outros fatores.

De iustitia et iure (Sobre el Derecho y la Justicia en Roma

Directory of Open Access Journals (Sweden)

Iglesias-Redondo, Juan

2003-07-01

Full Text Available Hablar del Derecho en Roma es hablar de la Justicia, pues el Derecho no puede tener otro fin que no sea el de la realización de «lo bueno y de lo justo». Y si el Derecho es norma de convivencia, haciendo posible la vida en común, importa considerar que nada tiene que ver con «mundos vaporosos o etéreos», porque el Derecho es justicia, y ésta se cierne sobre «la realidad viva del suceso humano». Definida la justicia en Roma como «la constante y perpetua voluntad de dar a cada uno su derecho», debe ponerse suficientemente de relieve que se trata de una idea de justicia que, estableciendo una cierta igualdad entre los hombres, propende a la consecución del bien común. Mas importa prestar importancia en Roma a «un formidable orden social no jurídico», instado por el mundo de la moralidad social, que actúa a modo de «complemento extrajurídico».

Research of Subgraph Estimation Page Rank Algorithm for Web Page Rank

Directory of Open Access Journals (Sweden)

LI Lan-yin

2017-04-01

Full Text Available The traditional PageRank algorithm can not efficiently perform large data Webpage scheduling problem. This paper proposes an accelerated algorithm named topK-Rank，which is based on PageRank on the MapReduce platform. It can find top k nodes efficiently for a given graph without sacrificing accuracy. In order to identify top k nodes，topK-Rank algorithm prunes unnecessary nodes and edges in each iteration to dynamically construct subgraphs，and iteratively estimates lower/upper bounds of PageRank scores through subgraphs. Theoretical analysis shows that this method guarantees result exactness. Experiments show that topK-Rank algorithm can find k nodes much faster than the existing approaches.

National minorities in Brno. The cultural heritage of Roma in excluded locations

Czech Academy of Sciences Publication Activity Database

Pospíšilová, Jana; Poláková, J.; Brožovičová, K.

2015-01-01

Roč. 25, č. 5 (2015), s. 18-34 ISSN 0862-8351 Institutional support: RVO:68378076 Keywords : National minorities * Roma * Cultural heritage * exclusion * Brno Subject RIV: AC - Archeology, Anthropology, Ethnology

Roadmap for Scaling and Multifractals in Geosciences: still a long way to go ?

Science.gov (United States)

Schertzer, Daniel; Lovejoy, Shaun

2010-05-01

The interest in scale symmetries (scaling) in Geosciences has never lessened since the first pioneering EGS session on chaos and fractals 22 years ago. The corresponding NP activities have been steadily increasing, covering a wider and wider diversity of geophysical phenomena and range of space-time scales. Whereas interest was initially largely focused on atmospheric turbulence, rain and clouds at small scales, it has quickly broadened to much larger scales and to much wider scale ranges, to include ocean sciences, solid earth and space physics. Indeed, the scale problem being ubiquitous in Geosciences, it is indispensable to share the efforts and the resulting knowledge as much as possible. There have been numerous achievements which have followed from the exploration of larger and larger datasets with finer and finer resolutions, from both modelling and theoretical discussions, particularly on formalisms for intermittency, anisotropy and scale symmetry, multiple scaling (multifractals) vs. simple scaling,. We are now way beyond the early pioneering but tentative attempts using crude estimates of unique scaling exponents to bring some credence to the fact that scale symmetries are key to most nonlinear geoscience problems. Nowadays, we need to better demonstrate that scaling brings effective solutions to geosciences and therefore to society. A large part of the answer corresponds to our capacity to create much more universal and flexible tools to multifractally analyse in straightforward and reliable manners complex and complicated systems such as the climate. Preliminary steps in this direction are already quite encouraging: they show that such approaches explain both the difficulty of classical techniques to find trends in climate scenarios (particularly for extremes) and resolve them with the help of scaling estimators. The question of the reliability and accuracy of these methods is not trivial. After discussing these important, but rather short term issues

Multifractal aspects of the scaling laws in fully developed compressible turbulence

International Nuclear Information System (INIS)

Shivamoggi, B.K.

1995-01-01

In this paper, multifractal aspects of the scalings laws in fully developed compressible turbulence are considered. Compressibility effects on known results of incompressible turbulence are pointed out. copyright 1995 Academic Press, Inc

A Rolling Element Bearing Fault Diagnosis Approach Based on Multifractal Theory and Gray Relation Theory.

Science.gov (United States)

Li, Jingchao; Cao, Yunpeng; Ying, Yulong; Li, Shuying

2016-01-01

Bearing failure is one of the dominant causes of failure and breakdowns in rotating machinery, leading to huge economic loss. Aiming at the nonstationary and nonlinear characteristics of bearing vibration signals as well as the complexity of condition-indicating information distribution in the signals, a novel rolling element bearing fault diagnosis method based on multifractal theory and gray relation theory was proposed in the paper. Firstly, a generalized multifractal dimension algorithm was developed to extract the characteristic vectors of fault features from the bearing vibration signals, which can offer more meaningful and distinguishing information reflecting different bearing health status in comparison with conventional single fractal dimension. After feature extraction by multifractal dimensions, an adaptive gray relation algorithm was applied to implement an automated bearing fault pattern recognition. The experimental results show that the proposed method can identify various bearing fault types as well as severities effectively and accurately.

Multifractal spectra in homogeneous shear flow

Science.gov (United States)

Deane, A. E.; Keefe, L. R.

1988-01-01

Employing numerical simulations of 3-D homogeneous shear flow, the associated multifractal spectra of the energy dissipation, scalar dissipation and vorticity fields were calculated. The results for (128) cubed simulations of this flow, and those obtained in recent experiments that analyzed 1- and 2-D intersections of atmospheric and laboratory flows, are in some agreement. A two-scale Cantor set model of the energy cascade process which describes the experimental results from 1-D intersections quite well, describes the 3-D results only marginally.

24 CFR 599.401 - Ranking of applications.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Ranking of applications. 599.401... Communities § 599.401 Ranking of applications. (a) Ranking order. Rural and urban applications will be ranked... applications ranked first. (b) Separate ranking categories. After initial ranking, both rural and urban...

Ranking Specific Sets of Objects.

Science.gov (United States)

Maly, Jan; Woltran, Stefan

2017-01-01

Ranking sets of objects based on an order between the single elements has been thoroughly studied in the literature. In particular, it has been shown that it is in general impossible to find a total ranking - jointly satisfying properties as dominance and independence - on the whole power set of objects. However, in many applications certain elements from the entire power set might not be required and can be neglected in the ranking process. For instance, certain sets might be ruled out due to hard constraints or are not satisfying some background theory. In this paper, we treat the computational problem whether an order on a given subset of the power set of elements satisfying different variants of dominance and independence can be found, given a ranking on the elements. We show that this problem is tractable for partial rankings and NP-complete for total rankings.

Multifractal Approach to Time Clustering of Earthquakes. Application to Mt. Vesuvio Seismicity

Science.gov (United States)

Codano, C.; Alonzo, M. L.; Vilardo, G.

The clustering structure of the Vesuvian earthquakes occurring is investigated by means of statistical tools: the inter-event time distribution, the running mean and the multifractal analysis. The first cannot clearly distinguish between a Poissonian process and a clustered one due to the difficulties of clearly distinguishing between an exponential distribution and a power law one. The running mean test reveals the clustering of the earthquakes, but looses information about the structure of the distribution at global scales. The multifractal approach can enlighten the clustering at small scales, while the global behaviour remains Poissonian. Subsequently the clustering of the events is interpreted in terms of diffusive processes of the stress in the earth crust.

Repair, redistribution and repopulation in V79 spheroids during multifraction irradiation

International Nuclear Information System (INIS)

Brown, R.C.; Durand, R.E.

1994-01-01

We used cells growing as multicell spheroids to determine whether the initial radiation response would be predictive for multifraction exposures, or whether other factors including repopulation rate should be considered. Potential problems of hypoxia and reoxygenation were avoided by using small spheroids which had not yet developed radiobiologically hypoxic regions. Repair and redistribution dominated the responses in the first two or three exposures, with repopulation playing a minor role. As the fractionation schedule was extended, however, repopulation between fractions largely determined the number of viable cells per spheroid. We conclude that the radiation response of cells from untreated spheroids provides a general indication of net sensitivity, but that repair and redistribution produces considerable variation in radiosensitivity throughout a fractionation protocol. Ultimately, repopulation effects may dominate the multifraction response. (Author)

Multifractal Downscaling of Rainfall Using Normalized Difference Vegetation Index (NDVI) in the Andes Plateau.

Science.gov (United States)

Duffaut Espinosa, L A; Posadas, A N; Carbajal, M; Quiroz, R

2017-01-01

In this paper, a multifractal downscaling technique is applied to adequately transformed and lag corrected normalized difference vegetation index (NDVI) in order to obtain daily estimates of rainfall in an area of the Peruvian Andean high plateau. This downscaling procedure is temporal in nature since the original NDVI information is provided at an irregular temporal sampling period between 8 and 11 days, and the desired final scale is 1 day. The spatial resolution of approximately 1 km remains the same throughout the downscaling process. The results were validated against on-site measurements of meteorological stations distributed in the area under study.

Culture and the School: The Degree of Educational Integration of Roma and Gypsies in the Peloponnese Region of Greece

Science.gov (United States)

Kiprianos, Pandelis; Daskalaki, Ivi; Stamelos, Georgios B.

2012-01-01

This article examines the degree of integration of Roma and Gypsy children in formal education in the Peloponnese region of Greece. It is based on field research conducted by the University of Patras during the school year 2006/07 within the framework of the Greek Ministry of Education's "Integration of Roma children in school"…

Renegotiating Relations among Teacher, Community, and Students: A Case Study of Teaching Roma Students in a Second Chance Program

Science.gov (United States)

Stoilescu, Dorian; Carapanait, Greta

2011-01-01

Prejudice and systematic discrimination have often been mentioned as major causes for the chronic underachievement of Roma students. In this paper we present a case study of a Romanian teacher involved in Second Chance, an educational program implemented in Romania in 2004 for the benefit of disadvantaged groups such as the Roma population. Since…

Classification of Prolapsed Mitral Valve versus Healthy Heart from Phonocardiograms by Multifractal Analysis

Directory of Open Access Journals (Sweden)

Ana Gavrovska

2013-01-01

Full Text Available Phonocardiography has shown a great potential for developing low-cost computer-aided diagnosis systems for cardiovascular monitoring. So far, most of the work reported regarding cardiosignal analysis using multifractals is oriented towards heartbeat dynamics. This paper represents a step towards automatic detection of one of the most common pathological syndromes, so-called mitral valve prolapse (MVP, using phonocardiograms and multifractal analysis. Subtle features characteristic for MVP in phonocardiograms may be difficult to detect. The approach for revealing such features should be locally based rather than globally based. Nevertheless, if their appearances are specific and frequent, they can affect a multifractal spectrum. This has been the case in our experiment with the click syndrome. Totally, 117 pediatric phonocardiographic recordings (PCGs, 8 seconds long each, obtained from 117 patients were used for PMV automatic detection. We propose a two-step algorithm to distinguish PCGs that belong to children with healthy hearts and children with prolapsed mitral valves (PMVs. Obtained results show high accuracy of the method. We achieved 96.91% accuracy on the dataset (97 recordings. Additionally, 90% accuracy is achieved for the evaluation dataset (20 recordings. Content of the datasets is confirmed by the echocardiographic screening.

Strong anticipation: Multifractal cascade dynamics modulate scaling in synchronization behaviors

International Nuclear Information System (INIS)

Stephen, Damian G.; Dixon, James A.

2011-01-01

Research highlights: → We investigated anticipatory behaviors in response to chaotic metronomes. → We assessed multifractal structure in tap intervals and onset intervals. → Strength of multifractality in tap intervals appears to match that in onset intervals. - Abstract: Previous research on anticipatory behaviors has found that the fractal scaling of human behavior may attune to the fractal scaling of an unpredictable signal [Stephen DG, Stepp N, Dixon JA, Turvey MT. Strong anticipation: Sensitivity to long-range correlations in synchronization behavior. Physica A 2008;387:5271-8]. We propose to explain this attunement as a case of multifractal cascade dynamics [Schertzer D, Lovejoy S. Generalised scale invariance in turbulent phenomena. Physico-Chem Hydrodyn J 1985;6:623-5] in which perceptual-motor fluctuations are coordinated across multiple time scales. This account will serve to sharpen the contrast between strong and weak anticipation: whereas the former entails a sensitivity to the intermittent temporal structure of an unpredictable signal, the latter simply predicts sensitivity to an aggregate description of an unpredictable signal irrespective of actual sequence. We pursue this distinction through a reanalysis of Stephen et al.'s data by examining the relationship between the widths of singularity spectra for intertap interval time series and for each corresponding interonset interval time series. We find that the attunement of fractal scaling reported by Stephen et al. was not the trivial result of sensitivity to temporal structure in aggregate but reflected a subtle sensitivity to the coordination across multiple time scales of fluctuation in the unpredictable signal.

Racial, Ethnic, or National Minority? Legal Discourses and Policy Frameworks on the Roma in Hungary and Beyond

Directory of Open Access Journals (Sweden)

Andras L. Pap

2015-09-01

Full Text Available Inspired by recent Hungarian legislative developments that, in reference to the Roma minority, exchanged the term “ethnic minority” with “nationality”, by providing a detailed case study of the development and morphology of policy measures and frameworks in Hungary, the article provides a general assessment of the relationship between policy instruments and terminology: that is, definitions and conceptualizations in international and domestic legal and policy documents for minority groups. The author argues that while terminology in itself is not a reliable signifier for policy frameworks, it may reveal contradictory group conceptualization and inconsistent policy-making. In regards to the Roma, the author claims that the inconsistent labelling as an ethnic, racial and national minority reflects the lack of consistent conceptualization of who the Roma are, and what should be done with them.

Multifractal Modeling of Turbulent Mixing

Science.gov (United States)

Samiee, Mehdi; Zayernouri, Mohsen; Meerschaert, Mark M.

2017-11-01

Stochastic processes in random media are emerging as interesting tools for modeling anomalous transport phenomena. Applications include intermittent passive scalar transport with background noise in turbulent flows, which are observed in atmospheric boundary layers, turbulent mixing in reactive flows, and long-range dependent flow fields in disordered/fractal environments. In this work, we propose a nonlocal scalar transport equation involving the fractional Laplacian, where the corresponding fractional index is linked to the multifractal structure of the nonlinear passive scalar power spectrum. This work was supported by the AFOSR Young Investigator Program (YIP) award (FA9550-17-1-0150) and partially by MURI/ARO (W911NF-15-1-0562).

Different Multifractal Scaling of the 0 cm Average Ground Surface Temperature of Four Representative Weather Stations over China

Directory of Open Access Journals (Sweden)

Lei Jiang

2013-01-01

Full Text Available The temporal scaling properties of the daily 0 cm average ground surface temperature (AGST records obtained from four selected sites over China are investigated using multifractal detrended fluctuation analysis (MF-DFA method. Results show that the AGST records at all four locations exhibit strong persistence features and different scaling behaviors. The differences of the generalized Hurst exponents are very different for the AGST series of each site reflecting the different scaling behaviors of the fluctuation. Furthermore, the strengths of multifractal spectrum are different for different weather stations and indicate that the multifractal behaviors vary from station to station over China.

Measuring complexity with multifractals in texts. Translation effects

International Nuclear Information System (INIS)

Ausloos, M.

2012-01-01

Highlights: ► Two texts in English and one in Esperanto are transformed into 6 time series. ► D(q) and f(alpha) of such (and shuffled) time series are obtained. ► A model for text construction is presented based on a parametrized Cantor set. ► The model parameters can also be used when examining machine translated texts. ► Suggested extensions to higher dimensions: in 2D image analysis and on hypertexts. - Abstract: Should quality be almost a synonymous of complexity? To measure quality appears to be audacious, even very subjective. It is hereby proposed to use a multifractal approach in order to quantify quality, thus through complexity measures. A one-dimensional system is examined. It is known that (all) written texts can be one-dimensional nonlinear maps. Thus, several written texts by the same author are considered, together with their translation, into an unusual language, Esperanto, and asa baseline their corresponding shuffled versions. Different one-dimensional time series can be used: e.g. (i) one based on word lengths, (ii) the other based on word frequencies; both are used for studying, comparing and discussing the map structure. It is shown that a variety in style can be measured through the D(q) and f(α) curves characterizing multifractal objects. This allows to observe on the one hand whether natural and artificial languages significantly influence the writing and the translation, and whether one author’s texts differ technically from each other. In fact, the f(α) curves of the original texts are similar to each other, but the translated text shows marked differences. However in each case, the f(α) curves are far from being parabolic, – in contrast to the shuffled texts. Moreover, the Esperanto text has more extreme values. Criteria are thereby suggested for estimating a text quality, as if it is a time series only. A model is introduced in order to substantiate the findings: it consists in considering a text as a random Cantor set

Multifractality and value-at-risk forecasting of exchange rates

Science.gov (United States)

Batten, Jonathan A.; Kinateder, Harald; Wagner, Niklas

2014-05-01

This paper addresses market risk prediction for high frequency foreign exchange rates under nonlinear risk scaling behaviour. We use a modified version of the multifractal model of asset returns (MMAR) where trading time is represented by the series of volume ticks. Our dataset consists of 138,418 5-min round-the-clock observations of EUR/USD spot quotes and trading ticks during the period January 5, 2006 to December 31, 2007. Considering fat-tails, long-range dependence as well as scale inconsistency with the MMAR, we derive out-of-sample value-at-risk (VaR) forecasts and compare our approach to historical simulation as well as a benchmark GARCH(1,1) location-scale VaR model. Our findings underline that the multifractal properties in EUR/USD returns in fact have notable risk management implications. The MMAR approach is a parsimonious model which produces admissible VaR forecasts at the 12-h forecast horizon. For the daily horizon, the MMAR outperforms both alternatives based on conditional as well as unconditional coverage statistics.

Cosmic microwave background and inflation in multi-fractional spacetimes

Energy Technology Data Exchange (ETDEWEB)

Calcagni, Gianluca [Instituto de Estructura de la Materia,CSIC, Serrano 121, 28006 Madrid (Spain); Kuroyanagi, Sachiko [Department of Physics, Nagoya University,Chikusa, Nagoya 464-8602 (Japan); Institute for Advanced Research, Nagoya University,Chikusa, Nagoya 464-8602 (Japan); Tsujikawa, Shinji [Department of Physics, Faculty of Science, Tokyo University of Science,1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan)

2016-08-18

We use FIRAS and Planck 2015 data to place observational bounds on inflationary scenarios in multi-fractional spacetimes with q-derivatives. While a power-law expansion in the geometric time coordinate is subject to the usual constraints from the tensor-to-scalar ratio, model-independent best fits of the black-body and scalar spectra yield upper limits on the free parameters of the multi-fractal measure of the theory. When the measure describing the fractal spacetime geometry is non-oscillating, information on the CMB black-body spectrum places constraints on the theory independent from but weaker than those obtained from the Standard Model, astrophysical gravitational waves and gamma-ray bursts (GRBs). When log oscillations are included and the measure describes a discrete fractal spacetime at microscopic scales, we obtain the first observational constraints on the amplitudes of such oscillations and find, in general, strong constraints on the multi-scale geometry and on the dimension of space. These results complete the scan and reduction of the parameter space of the theory. Black-body bounds are obtained also for the theory with weighted derivatives.

Cosmic microwave background and inflation in multi-fractional spacetimes

International Nuclear Information System (INIS)

Calcagni, Gianluca; Kuroyanagi, Sachiko; Tsujikawa, Shinji

2016-01-01

We use FIRAS and Planck 2015 data to place observational bounds on inflationary scenarios in multi-fractional spacetimes with q-derivatives. While a power-law expansion in the geometric time coordinate is subject to the usual constraints from the tensor-to-scalar ratio, model-independent best fits of the black-body and scalar spectra yield upper limits on the free parameters of the multi-fractal measure of the theory. When the measure describing the fractal spacetime geometry is non-oscillating, information on the CMB black-body spectrum places constraints on the theory independent from but weaker than those obtained from the Standard Model, astrophysical gravitational waves and gamma-ray bursts (GRBs). When log oscillations are included and the measure describes a discrete fractal spacetime at microscopic scales, we obtain the first observational constraints on the amplitudes of such oscillations and find, in general, strong constraints on the multi-scale geometry and on the dimension of space. These results complete the scan and reduction of the parameter space of the theory. Black-body bounds are obtained also for the theory with weighted derivatives.

Multifractal investigation of continuous seismic signal recorded at El Hierro volcano (Canary Islands) during the 2011-2012 pre- and eruptive phases

Science.gov (United States)

Telesca, Luciano; Lovallo, Michele; Martì Molist, Joan; López Moreno, Carmen; Abella Meléndez, Rafael

2015-02-01

The Multifractal Detrended Fluctuation Analysis (MF-DFA) is an effective method that allows detecting multifractality in non-stationary signals. We applied the MF-DFA to the continuous seismic signal recorded at El Hierro volcano (Canary Islands), which was affected by a submarine monogenetic eruption in October 2011. We investigated the multifractal properties of the continuous seismic signal before the onset of the eruption and after. We analysed three frames of the signal, one measured before the onset of eruption that occurred on October 10, 2011; and two after, but corresponding to two distinct eruptive episodes, the second one started on November 22, 2011 and lasting until late February 2012. The results obtained show a striking difference in the width of the multifractal spectrum, which is generally used to quantify the multifractal degree of a signal: the multifractal spectra of the signal frames recorded during the eruptive episodes are almost identical and much narrower than that of the signal frame measured before the onset of the eruption. Such difference indicates that the seismic signal recorded during the unrest reflects mostly the fracturing of the host rock under the overpressure exerted by the intruding magma, while that corresponding to the eruptive phases was mostly influenced by the flow of magma through the plumbing system, even some fracturing remains, not being possible to distinguish among the two eruptive episodes in terms of rock fracture mechanics.

Financial market volatility and contagion effect: A copula-multifractal volatility approach

Science.gov (United States)

Chen, Wang; Wei, Yu; Lang, Qiaoqi; Lin, Yu; Liu, Maojuan

2014-03-01

In this paper, we propose a new approach based on the multifractal volatility method (MFV) to study the contagion effect between the U.S. and Chinese stock markets. From recent studies, which reveal that multifractal characteristics exist in both developed and emerging financial markets, according to the econophysics literature we could draw conclusions as follows: Firstly, we estimate volatility using the multifractal volatility method, and find out that the MFV method performs best among other volatility models, such as GARCH-type and realized volatility models. Secondly, we analyze the tail dependence structure between the U.S. and Chinese stock market. The estimated static copula results for the entire period show that the SJC copula performs best, indicating asymmetric characteristics of the tail dependence structure. The estimated dynamic copula results show that the time-varying t copula achieves the best performance, which means the symmetry dynamic t copula is also a good choice, for it is easy to estimate and is able to depict both the upper and lower tail dependence structure. Finally, with the results of the previous two steps, we analyze the contagion effect between the U.S. and Chinese stock markets during the subprime mortgage crisis. The empirical results show that the subprime mortgage crisis started in the U.S. and that its stock market has had an obvious contagion effect on the Chinese stock market. Our empirical results should/might be useful for investors allocating their portfolios.

Multifractality, efficiency analysis of Chinese stock market and its cross-correlation with WTI crude oil price

Science.gov (United States)

Zhuang, Xiaoyang; Wei, Yu; Ma, Feng

2015-07-01

In this paper, the multifractality and efficiency degrees of ten important Chinese sectoral indices are evaluated using the methods of MF-DFA and generalized Hurst exponents. The study also scrutinizes the dynamics of the efficiency of Chinese sectoral stock market by the rolling window approach. The overall empirical findings revealed that all the sectoral indices of Chinese stock market exist different degrees of multifractality. The results of different efficiency measures have agreed on that the 300 Materials index is the least efficient index. However, they have a slight diffidence on the most efficient one. The 300 Information Technology, 300 Telecommunication Services and 300 Health Care indices are comparatively efficient. We also investigate the cross-correlations between the ten sectoral indices and WTI crude oil price based on Multifractal Detrended Cross-correlation Analysis. At last, some relevant discussions and implications of the empirical results are presented.

The effects of observational correlated noises on multifractal detrended fluctuation analysis

Science.gov (United States)

Gulich, Damián; Zunino, Luciano

2012-08-01

We have numerically investigated the effects that observational correlated noises have on the generalized Hurst exponents, h(q), estimated by using the multifractal generalization of detrended fluctuation analysis (MF-DFA). More precisely, artificially generated stochastic binomial multifractals with increased amount of colored noises were analyzed via MF-DFA. It has been recently shown that for moderate additions of white noise, the generalized Hurst exponents are significantly underestimated for qeffects of additive noise, short- term memory and periodic trends, Physica A 390 (2011) 2480-2490]. In this paper, we have found that h(q) with q≥2 are also affected when correlated noises are considered. This is due to the fact that the spurious correlations influence the scaling behaviors associated to large fluctuations. The results obtained are significant for practical situations, where noises with different correlations are inherently present.

Characterization of turbulence stability through the identification of multifractional Brownian motions

Science.gov (United States)

Lee, K. C.

2013-02-01

Multifractional Brownian motions have become popular as flexible models in describing real-life signals of high-frequency features in geoscience, microeconomics, and turbulence, to name a few. The time-changing Hurst exponent, which describes regularity levels depending on time measurements, and variance, which relates to an energy level, are two parameters that characterize multifractional Brownian motions. This research suggests a combined method of estimating the time-changing Hurst exponent and variance using the local variation of sampled paths of signals. The method consists of two phases: initially estimating global variance and then accurately estimating the time-changing Hurst exponent. A simulation study shows its performance in estimation of the parameters. The proposed method is applied to characterization of atmospheric stability in which descriptive statistics from the estimated time-changing Hurst exponent and variance classify stable atmosphere flows from unstable ones.

Characterization of turbulence stability through the identification of multifractional Brownian motions

Directory of Open Access Journals (Sweden)

K. C. Lee

2013-02-01

Full Text Available Multifractional Brownian motions have become popular as flexible models in describing real-life signals of high-frequency features in geoscience, microeconomics, and turbulence, to name a few. The time-changing Hurst exponent, which describes regularity levels depending on time measurements, and variance, which relates to an energy level, are two parameters that characterize multifractional Brownian motions. This research suggests a combined method of estimating the time-changing Hurst exponent and variance using the local variation of sampled paths of signals. The method consists of two phases: initially estimating global variance and then accurately estimating the time-changing Hurst exponent. A simulation study shows its performance in estimation of the parameters. The proposed method is applied to characterization of atmospheric stability in which descriptive statistics from the estimated time-changing Hurst exponent and variance classify stable atmosphere flows from unstable ones.

Os labirintos da cidade: Marcial em Roma

OpenAIRE

Torrão, João Manuel Nunes; Andrade, António Manuel Lopes

2008-01-01

Martial had unparalleled knowledge of the city of Rome and he provides guidance to todays’s readers in the street maze of the city. That city had specific feaures which made the circulation of people and vehicles difficult, in spite of the efforts made by some politicians to improve the urban network. Marcial conhecia como ninguém a cidade de Roma e serve de guia aos leitores da actualidade através das ruas labirínticas da Urbe. Essa cidade apresentava características especí...

Sêneca e o ambiente hebraico de Roma

Directory of Open Access Journals (Sweden)

José Carlos Silva de Almeida

2013-05-01

Full Text Available Enquanto ocupante de um cargo importante no Império Romano do I século, Sêneca certamente conheceu vários dos ensinamentos e práticas da comunidade hebraica de Roma, conforme observamos em alguns trechos de sua obra e de autores posteriores. Se por um lado seu pensamento parece se aproximar da doutrina e prática hebraicas, embora por razões diversas, por outro lado se afasta. Todavia ele soube, como nenhum outro escritor latino, manifestar o devido respeito e reserva ao ambiente hebraico da Urbs.

Effect of ethnicity on clinical presentation and risk of antiphospholipid syndrome in Roma and Caucasian patients with systemic lupus erythematosus: a multicenter cross-sectional study.

Science.gov (United States)

Manzano-Gamero, Victoria; Pardo-Cabello, Alfredo J; Vargas-Hitos, José A; Zamora-Pasadas, Mónica; Navarrete-Navarrete, Nuria; Sabio, José M; Jáimez-Gámiz, Laura; Ríos-Fernandez, Raquel; Ortego-Centeno, Norberto; Ayala-Gutierrez, M Mar; de Ramón, Enrique; Colodro-Ruíz, Agustín; Micó-Giner, Luisa; Castillo-Palma, María J; Robles-Marhuenda, Ángel; Luna-Del Castillo, Juan de Dios; Jiménez-Alonso, Juan

2017-06-07

To determine if there are ethnic differences in the prevalence of antiphospholipid syndrome (APS), clinical presentation and autoantibody profile between Roma and Caucasian patients with systemic lupus erythematosus (SLE). A cross-sectional study was conducted including data from Roma and Caucasian SLE patients consecutively attending six hospitals in Spain. Socio-demographic characteristics, prevalence of APS, clinical and analytical features of SLE and APS were compared between ethnic groups. Data from 52 Roma and 98 Caucasian SLE patients were included. Roma SLE patients had a higher risk (odds ratio 2.56, 95% CI 1.02-6.39) and prevalence of APS (28.8% vs. 13.3%, P = 0.027). Furthermore, Roma SLE patients had a statistically significant higher prevalence of abortions (23.5% vs. 10.2%, P = 0.049). In relation to other APS diagnostic criteria, Roma SLE patients had a non-statistically significant higher prevalence of fetal deaths (14.3% vs. 5.1%, P = 0.106) and thrombotic events (21.1% vs. 12.2%, P = 0.160). In relation to SLE clinical features, Roma patients had a significantly higher prevalence of arthritis (75% vs. 57.1%, P = 0.034) and non-significant higher prevalence of serositis (44.2% vs. 29.6%, P = 0.104), discoid lesions (11.5% vs. 5.1%, P = 0.191), oral ulcers (46.1% vs. 34.7%, P = 0.218) and livedo reticularis (21.1% vs. 15.3%, P = 0.374). No statistically significant differences were found in the Systemic Lupus International Collaborating Clinics Damage Index or the autoimmune serological profile. Prevalence and risk of APS were significantly higher in Roma SLE patients. Furthermore, Roma patients had a significantly higher prevalence of abortions and a non-significant higher prevalence of fetal deaths and thrombotic events. © 2017 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.

A non linear analysis of human gait time series based on multifractal analysis and cross correlations

International Nuclear Information System (INIS)

Munoz-Diosdado, A

2005-01-01

We analyzed databases with gait time series of adults and persons with Parkinson, Huntington and amyotrophic lateral sclerosis (ALS) diseases. We obtained the staircase graphs of accumulated events that can be bounded by a straight line whose slope can be used to distinguish between gait time series from healthy and ill persons. The global Hurst exponent of these series do not show tendencies, we intend that this is because some gait time series have monofractal behavior and others have multifractal behavior so they cannot be characterized with a single Hurst exponent. We calculated the multifractal spectra, obtained the spectra width and found that the spectra of the healthy young persons are almost monofractal. The spectra of ill persons are wider than the spectra of healthy persons. In opposition to the interbeat time series where the pathology implies loss of multifractality, in the gait time series the multifractal behavior emerges with the pathology. Data were collected from healthy and ill subjects as they walked in a roughly circular path and they have sensors in both feet, so we have one time series for the left foot and other for the right foot. First, we analyzed these time series separately, and then we compared both results, with direct comparison and with a cross correlation analysis. We tried to find differences in both time series that can be used as indicators of equilibrium problems

A non linear analysis of human gait time series based on multifractal analysis and cross correlations

Energy Technology Data Exchange (ETDEWEB)

Munoz-Diosdado, A [Department of Mathematics, Unidad Profesional Interdisciplinaria de Biotecnologia, Instituto Politecnico Nacional, Av. Acueducto s/n, 07340, Mexico City (Mexico)

2005-01-01

We analyzed databases with gait time series of adults and persons with Parkinson, Huntington and amyotrophic lateral sclerosis (ALS) diseases. We obtained the staircase graphs of accumulated events that can be bounded by a straight line whose slope can be used to distinguish between gait time series from healthy and ill persons. The global Hurst exponent of these series do not show tendencies, we intend that this is because some gait time series have monofractal behavior and others have multifractal behavior so they cannot be characterized with a single Hurst exponent. We calculated the multifractal spectra, obtained the spectra width and found that the spectra of the healthy young persons are almost monofractal. The spectra of ill persons are wider than the spectra of healthy persons. In opposition to the interbeat time series where the pathology implies loss of multifractality, in the gait time series the multifractal behavior emerges with the pathology. Data were collected from healthy and ill subjects as they walked in a roughly circular path and they have sensors in both feet, so we have one time series for the left foot and other for the right foot. First, we analyzed these time series separately, and then we compared both results, with direct comparison and with a cross correlation analysis. We tried to find differences in both time series that can be used as indicators of equilibrium problems.

On the ranking of chemicals based on their PBT characteristics: comparison of different ranking methodologies using selected POPs as an illustrative example.

Science.gov (United States)

Sailaukhanuly, Yerbolat; Zhakupbekova, Arai; Amutova, Farida; Carlsen, Lars

2013-01-01

Knowledge of the environmental behavior of chemicals is a fundamental part of the risk assessment process. The present paper discusses various methods of ranking of a series of persistent organic pollutants (POPs) according to the persistence, bioaccumulation and toxicity (PBT) characteristics. Traditionally ranking has been done as an absolute (total) ranking applying various multicriteria data analysis methods like simple additive ranking (SAR) or various utility functions (UFs) based rankings. An attractive alternative to these ranking methodologies appears to be partial order ranking (POR). The present paper compares different ranking methods like SAR, UF and POR. Significant discrepancies between the rankings are noted and it is concluded that partial order ranking, as a method without any pre-assumptions concerning possible relation between the single parameters, appears as the most attractive ranking methodology. In addition to the initial ranking partial order methodology offers a wide variety of analytical tools to elucidate the interplay between the objects to be ranked and the ranking parameters. In the present study is included an analysis of the relative importance of the single P, B and T parameters. Copyright © 2012 Elsevier Ltd. All rights reserved.

Multifractal modelling and 3D lacunarity analysis

International Nuclear Information System (INIS)

Hanen, Akkari; Imen, Bhouri; Asma, Ben Abdallah; Patrick, Dubois; Hedi, Bedoui Mohamed

2009-01-01

This study presents a comparative evaluation of lacunarity of 3D grey level models with different types of inhomogeneity. A new method based on the 'Relative Differential Box Counting' was developed to estimate the lacunarity features of grey level volumes. To validate our method, we generated a set of 3D grey level multifractal models with random, anisotropic and hierarchical properties. Our method gives a lacunarity measurement correlated with the theoretical one and allows a better model classification compared with a classical approach.

A multifractal formalism for countable alphabet subshifts

International Nuclear Information System (INIS)

Meson, Alejandro; Vericat, Fernando

2009-01-01

We study here the multifractal spectrum of local entropies for subshifts with an infinite alphabet. The description of this spectrum is obtained from the Legendre transform of a free energy map and Gibbs states associated with adequate potentials. The lack of compactness in the symbolic space necessitates modifications to the description for the compact case, i.e. for finite alphabet. In particular, the class of potentials must be restricted to a narrower one than that considered for the compact case

Upper Estimates on the Higher-dimensional Multifractal Spectrum of Local Entropy%局部熵高维重分形谱的上界估计

Institute of Scientific and Technical Information of China (English)

严珍珍; 陈二才

2008-01-01

We discuss the problem of higher-dimensional multifractal spectrum of lo-cal entropy for arbitrary invariant measures. By utilizing characteristics of a dynam-ical system, namely, higher-dimensional entropy capacities and higher-dimensional correlation entropies, we obtain three upper estimates on the higher-dimensional mul-tifractal spectrum of local entropies. We also study the domain of higher-dimensional multifractal spetrum of entropies.

Universal multifractality in multiparticle production

International Nuclear Information System (INIS)

Florkowski, W.; Hwa, R.C.

1991-01-01

The G moments for the multifractal analysis of multiparticle production are investigated in a model-independent way. By successive bin splitting and assuming the existence of a multiplicity splitting function that depends on multiplicity, but applicable at all steps of the splittings, we study the ergodicity of horizontal and vertical averaging, and derive a universality relation for the G moments. It relates the G moments for different initial multiplicities to a common scaling function Γ q (ξ). The experimental verification of this scaling property would, on the one hand, signify self-similarity in the data, and, on the other, provide a convenient function for comparison not only among different experiments, but also between theory and experiment

The constitutional framework for regulation of the position of the Roma community in the Republic of Slovenia:

OpenAIRE

Zagorc, Saša

2007-01-01

In the first part, author questions the need to regulate the matters regarding the Roma Community in the highest legal act, as it was done in the Constitution of the Republic of Slovenia. He believes that the introduction of the collective rights in the Constitution may result as inappropriate in thelong-term. The second part deals with normative analysis of the status of Roma in Slovenia, in which the constitutional framework for protection of the national communities mentioned in the Consti...

Beyond Fractals and 1/f Noise: Multifractal Analysis of Complex Physiological Time Series

Science.gov (United States)

Ivanov, Plamen Ch.; Amaral, Luis A. N.; Ashkenazy, Yosef; Stanley, H. Eugene; Goldberger, Ary L.; Hausdorff, Jeffrey M.; Yoneyama, Mitsuru; Arai, Kuniharu

2001-03-01

We investigate time series with 1/f-like spectra generated by two physiologic control systems --- the human heartbeat and human gait. We show that physiological fluctuations exhibit unexpected ``hidden'' structures often described by scaling laws. In particular, our studies indicate that when analyzed on different time scales the heartbeat fluctuations exhibit cascades of branching patterns with self-similar (fractal) properties, characterized by long-range power-law anticorrelations. We find that these scaling features change during sleep and wake phases, and with pathological perturbations. Further, by means of a new wavelet-based technique, we find evidence of multifractality in the healthy human heartbeat even under resting conditions, and show that the multifractal character and nonlinear properties of the healthy heart are encoded in the Fourier phases. We uncover a loss of multifractality for a life-threatening condition, congestive heart failure. In contrast to the heartbeat, we find that the interstride interval time series of healthy human gait, a voluntary process under neural regulation, is described by a single fractal dimension (such as classical 1/f noise) indicating monofractal behavior. Thus our approach can help distinguish physiological and physical signals with comparable frequency spectra and two-point correlations, and guide modeling of their control mechanisms.

A multifractal detrended fluctuation analysis of financial market efficiency: Comparison using Dow Jones sector ETF indices

Science.gov (United States)

Tiwari, Aviral Kumar; Albulescu, Claudiu Tiberiu; Yoon, Seong-Min

2017-10-01

This study challenges the efficient market hypothesis, relying on the Dow Jones sector Exchange-Traded Fund (ETF) indices. For this purpose, we use the generalized Hurst exponent and multifractal detrended fluctuation analysis (MF-DFA) methods, using daily data over the timespan from 2000 to 2015. We compare the sector ETF indices in terms of market efficiency between short- and long-run horizons, small and large fluctuations, and before and after the global financial crisis (GFC). Our findings can be summarized as follows. First, there is clear evidence that the sector ETF markets are multifractal in nature. We also find a crossover in the multifractality of sector ETF market dynamics. Second, the utilities and consumer goods sector ETF markets are more efficient compared with the financial and telecommunications sector ETF markets, in terms of price prediction. Third, there are noteworthy discrepancies in terms of market efficiency, between the short- and long-term horizons. Fourth, the ETF market efficiency is considerably diminished after the global financial crisis.

Change in ranking order of prescribing patterns by age and sex standardization of the practice population--audit may be misleading

DEFF Research Database (Denmark)

Olesen, Frede; Vedsted, Peter; Nielsen, Jørgen Nørskov

1996-01-01

OBJECTIVE: To demonstrate whether standardization of practice populations by age and sex changes the internal prescription ranking order of a group of practices. DESIGN: Data on the prescribing of cardiovascular drugs in a group of practices were obtained from a county-based database. Information...... on the age, sex, and numbers of patients per practice was also obtained. The direct standardization method was used to adjust practice populations for age and sex. SETTING: The town of Randers, Aarhus County, Denmark. SUBJECTS: 35 practices, 41 GPs. MAIN OUTCOME MEASURES: Ranking of the 35 practices...... of the practices. Only four practices did not change ranking position, while four moved more than ten places. The slope between highest and lowest ranked practice did not diminish after standardization. CONCLUSION: Care should be taken when comparing peer prescribing patterns from crude utilization data, and we...

Multifractal rainfall extremes: Theoretical analysis and practical estimation

International Nuclear Information System (INIS)

Langousis, Andreas; Veneziano, Daniele; Furcolo, Pierluigi; Lepore, Chiara

2009-01-01

We study the extremes generated by a multifractal model of temporal rainfall and propose a practical method to estimate the Intensity-Duration-Frequency (IDF) curves. The model assumes that rainfall is a sequence of independent and identically distributed multiplicative cascades of the beta-lognormal type, with common duration D. When properly fitted to data, this simple model was found to produce accurate IDF results [Langousis A, Veneziano D. Intensity-duration-frequency curves from scaling representations of rainfall. Water Resour Res 2007;43. (doi:10.1029/2006WR005245)]. Previous studies also showed that the IDF values from multifractal representations of rainfall scale with duration d and return period T under either d → 0 or T → ∞, with different scaling exponents in the two cases. We determine the regions of the (d, T)-plane in which each asymptotic scaling behavior applies in good approximation, find expressions for the IDF values in the scaling and non-scaling regimes, and quantify the bias when estimating the asymptotic power-law tail of rainfall intensity from finite-duration records, as was often done in the past. Numerically calculated exact IDF curves are compared to several analytic approximations. The approximations are found to be accurate and are used to propose a practical IDF estimation procedure.

Teachers’ implicit beliefs about the students of the Roma and the Hungarian cultural group

Directory of Open Access Journals (Sweden)

Dimitrijević Bojana M.

2017-01-01

Full Text Available Research has shown that the beliefs about cultural, ethnic or racial diversities among students are vital for the effective work of teachers. Hence, in this paper, we aim at determining: (1 in what ways the teachers perceive and interpret the school situation that includes the students from a minority cultural group (Roma and Hungarian, i.e. what kinds of beliefs they express in the given situation; (2 whether there are any differences in the way in which teachers, within the same stadium of development of intercultural sensitivity, perceive the given situation. The sample included class teachers whose score on the Intercultural Development Inventory pointed to intercultural sensitivity in accordance with the stadium of minimisation (seventeen teachers and polarisation (six teachers. The Critical Incident Technique (CI was applied in the study, in two parallel forms: with a Hungarian and a Roma student. Thematic analysis yielded seven topics, four of which occurred only in the CI with a Roma student: Disrespecting school as an institution, Abuse of minority status, Separation from the class and Typical children’s motives. The comparison of teachers’ statements depending on the CI version and the developmental phase indicate that the specificity of a cultural group in question affects the expressed beliefs about this group, regardless of teachers’ intercultural sensitivity.

Risk factors for low vaccination coverage among Roma children in disadvantaged settlements in Belgrade, Serbia.

Science.gov (United States)

Stojanovski, Kristefer; McWeeney, Gerry; Emiroglu, Nedret; Ostlin, Piroska; Koller, Theadora; Licari, Lucianne; Kaluski, Dorit Nitzan

2012-08-10

Full vaccination coverage for children under 59 months of age in Serbia is over 90%. This study assesses vaccination coverage and examines its association with birth registration among Roma children who resided in disadvantaged settlements in Belgrade, Serbia. The First Roma Health and Nutrition Survey in Belgrade settlements, 2009, was conducted among households of 468 Roma children between the ages of 6-59 months. The 2005 WHO Immunization Coverage Cluster Survey sampling methodology was employed. Vaccinations were recorded using children's vaccination cards and through verification steps carried out in the Primary Health Care Centers. For those who had health records the information on vaccination was recorded. About 88% of children had vaccination cards. The mean rate of age appropriate full immunization was 16% for OPV and DTP and 14.3% for MMR. Multivariate analyses indicated that children whose births were registered with the civil authorities were more likely to have their vaccination cards [OR=6.1, CI (2.5, 15.0)] and to have their full, age appropriate, series vaccinations for DTP, OPV, MMR and HepB [OR=3.8, CI (1.5, 10.0), OR=3.2, CI (1.5, 6.6), OR=4.8, CI (1.1, 21.0), OR=5.4, CI (1.4, 21.6), respectively]. The immunization coverage among Roma children in settlements is far below the WHO/UNICEF MDG4 target in achieving prevention and control of vaccine preventable diseases. It demonstrates the need to include "invisible" populations into the health systems in continuous, integrated, comprehensive, accessible and sensitive modes. Copyright © 2012 Elsevier Ltd. All rights reserved.

Multifractality to Photonic Crystal & Self-Organization to Metamaterials through Anderson Localizations & Group/Gauge Theory

Science.gov (United States)

Hidajatullah-Maksoed, Widastra

2015-04-01

Arthur Cayley at least investigate by creating the theory of permutation group[F:∖∖Group_theory.htm] where in cell elements addressing of the lattice Qmf used a Cayley tree, the self-afine object Qmf is described by the combination of the finite groups of rotation & inversion and the infinite groups of translation & dilation[G Corso & LS Lacena: ``Multifractal lattice and group theory'', Physica A: Statistical Mechanics &Its Applications, 2005, v 357, issue I, h 64-70; http://www.sciencedirect.com/science/articel/pii/S0378437105005005 ] hence multifractal can be related to group theory. Many grateful Thanks to HE. Mr. Drs. P. SWANTORO & HE. Mr. Ir. SARWONO KUSUMAATMADJA.

Roma Hukuku’nda Gemi, Han ve Ahır İşletenlerin Receptum Sorumluluğu

Directory of Open Access Journals (Sweden)

Mehmet YEŞİLLER

2013-04-01

Full Text Available Çalışmamızda Roma Hukuku'nda gemi, han ve ahır işleten kimselerin sorumluluklarına ilişkin düzenlemeler ele alınmıştır. Roma?da özellikle gemi, han ve ahır işleten kimselerin yanlarında çalıştırdıkları kişilerin güvenilir olmamasından dolayı, taraflar arasındaki istisna sözleşmesinden kaynaklanan custodia sorumluluğuna ek olarak "actio de damno aut furto adversus nautas, caupones, stabularios ve receptum, nautae, cauponis, stabularii" sorumluluklarının düzenlendiği kaynaklardan anlaşılmaktadır. Praetor Edictum'larıyla sağlanan ve haksız fiil benzerlerine dayanan söz konusu bu uygulamaların, Roma'da istisna sözleşmesinin koruyamadığı alana ilişkin olarak geniş uygulama imkanı buldukları görülmektedir.

Multifractal modelling and 3D lacunarity analysis

Energy Technology Data Exchange (ETDEWEB)

Hanen, Akkari, E-mail: bettaieb.hanen@topnet.t [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia); Imen, Bhouri, E-mail: bhouri_imen@yahoo.f [Unite de recherche ondelettes et multifractals, Faculte des sciences (Tunisia); Asma, Ben Abdallah, E-mail: asma.babdallah@cristal.rnu.t [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia); Patrick, Dubois, E-mail: pdubois@chru-lille.f [INSERM, U 703, Lille (France); Hedi, Bedoui Mohamed, E-mail: medhedi.bedoui@fmm.rnu.t [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia)

2009-09-28

This study presents a comparative evaluation of lacunarity of 3D grey level models with different types of inhomogeneity. A new method based on the 'Relative Differential Box Counting' was developed to estimate the lacunarity features of grey level volumes. To validate our method, we generated a set of 3D grey level multifractal models with random, anisotropic and hierarchical properties. Our method gives a lacunarity measurement correlated with the theoretical one and allows a better model classification compared with a classical approach.

Log-Normality and Multifractal Analysis of Flame Surface Statistics

Science.gov (United States)

Saha, Abhishek; Chaudhuri, Swetaprovo; Law, Chung K.

2013-11-01

The turbulent flame surface is typically highly wrinkled and folded at a multitude of scales controlled by various flame properties. It is useful if the information contained in this complex geometry can be projected onto a simpler regular geometry for the use of spectral, wavelet or multifractal analyses. Here we investigate local flame surface statistics of turbulent flame expanding under constant pressure. First the statistics of local length ratio is experimentally obtained from high-speed Mie scattering images. For spherically expanding flame, length ratio on the measurement plane, at predefined equiangular sectors is defined as the ratio of the actual flame length to the length of a circular-arc of radius equal to the average radius of the flame. Assuming isotropic distribution of such flame segments we convolute suitable forms of the length-ratio probability distribution functions (pdfs) to arrive at corresponding area-ratio pdfs. Both the pdfs are found to be near log-normally distributed and shows self-similar behavior with increasing radius. Near log-normality and rather intermittent behavior of the flame-length ratio suggests similarity with dissipation rate quantities which stimulates multifractal analysis. Currently at Indian Institute of Science, India.

Black holes in multi-fractional and Lorentz-violating models

Energy Technology Data Exchange (ETDEWEB)

Calcagni, Gianluca [CSIC, Instituto de Estructura de la Materia, Madrid (Spain); Rodriguez Fernandez, David [Universidad de Oviedo, Department of Physics, Oviedo (Spain); Ronco, Michele [Universita di Roma ' ' La Sapienza' ' , Dipartimento di Fisica, Rome (Italy); INFN, Rome (Italy)

2017-05-15

We study static and radially symmetric black holes in the multi-fractional theories of gravity with q-derivatives and with weighted derivatives, frameworks where the spacetime dimension varies with the probed scale and geometry is characterized by at least one fundamental length l{sub *}. In the q-derivatives scenario, one finds a tiny shift of the event horizon. Schwarzschild black holes can present an additional ring singularity, not present in general relativity, whose radius is proportional to l{sub *}. In the multi-fractional theory with weighted derivatives, there is no such deformation, but non-trivial geometric features generate a cosmological-constant term, leading to a de Sitter-Schwarzschild black hole. For both scenarios, we compute the Hawking temperature and comment on the resulting black-hole thermodynamics. In the case with q-derivatives, black holes can be hotter than usual and possess an additional ring singularity, while in the case with weighted derivatives they have a de Sitter hair of purely geometric origin, which may lead to a solution of the cosmological constant problem similar to that in unimodular gravity. Finally, we compare our findings with other Lorentz-violating models. (orig.)

Black holes in multi-fractional and Lorentz-violating models

International Nuclear Information System (INIS)

Calcagni, Gianluca; Rodriguez Fernandez, David; Ronco, Michele

2017-01-01

We study static and radially symmetric black holes in the multi-fractional theories of gravity with q-derivatives and with weighted derivatives, frameworks where the spacetime dimension varies with the probed scale and geometry is characterized by at least one fundamental length l_*. In the q-derivatives scenario, one finds a tiny shift of the event horizon. Schwarzschild black holes can present an additional ring singularity, not present in general relativity, whose radius is proportional to l_*. In the multi-fractional theory with weighted derivatives, there is no such deformation, but non-trivial geometric features generate a cosmological-constant term, leading to a de Sitter-Schwarzschild black hole. For both scenarios, we compute the Hawking temperature and comment on the resulting black-hole thermodynamics. In the case with q-derivatives, black holes can be hotter than usual and possess an additional ring singularity, while in the case with weighted derivatives they have a de Sitter hair of purely geometric origin, which may lead to a solution of the cosmological constant problem similar to that in unimodular gravity. Finally, we compare our findings with other Lorentz-violating models. (orig.)

ABC of multi-fractal spacetimes and fractional sea turtles

Energy Technology Data Exchange (ETDEWEB)

Calcagni, Gianluca [Instituto de Estructura de la Materia, CSIC, Madrid (Spain)

2016-04-15

We clarify what it means to have a spacetime fractal geometry in quantum gravity and show that its properties differ from those of usual fractals. A weak and a strong definition of multi-scale and multi-fractal spacetimes are given together with a sketch of the landscape of multi-scale theories of gravitation. Then, in the context of the fractional theory with q-derivatives, we explore the consequences of living in a multi-fractal spacetime. To illustrate the behavior of a non-relativistic body, we take the entertaining example of a sea turtle. We show that, when only the time direction is fractal, sea turtles swim at a faster speed than in an ordinary world, while they swim at a slower speed if only the spatial directions are fractal. The latter type of geometry is the one most commonly found in quantum gravity. For time-like fractals, relativistic objects can exceed the speed of light, but strongly so only if their size is smaller than the range of particle-physics interactions. We also find new results about log-oscillating measures, the measure presentation and their role in physical observations and in future extensions to nowhere-differentiable stochastic spacetimes. (orig.)

ABC of multi-fractal spacetimes and fractional sea turtles

International Nuclear Information System (INIS)

Calcagni, Gianluca

2016-01-01

We clarify what it means to have a spacetime fractal geometry in quantum gravity and show that its properties differ from those of usual fractals. A weak and a strong definition of multi-scale and multi-fractal spacetimes are given together with a sketch of the landscape of multi-scale theories of gravitation. Then, in the context of the fractional theory with q-derivatives, we explore the consequences of living in a multi-fractal spacetime. To illustrate the behavior of a non-relativistic body, we take the entertaining example of a sea turtle. We show that, when only the time direction is fractal, sea turtles swim at a faster speed than in an ordinary world, while they swim at a slower speed if only the spatial directions are fractal. The latter type of geometry is the one most commonly found in quantum gravity. For time-like fractals, relativistic objects can exceed the speed of light, but strongly so only if their size is smaller than the range of particle-physics interactions. We also find new results about log-oscillating measures, the measure presentation and their role in physical observations and in future extensions to nowhere-differentiable stochastic spacetimes. (orig.)

Black holes in multi-fractional and Lorentz-violating models.

Science.gov (United States)

Calcagni, Gianluca; Rodríguez Fernández, David; Ronco, Michele

2017-01-01

We study static and radially symmetric black holes in the multi-fractional theories of gravity with q -derivatives and with weighted derivatives, frameworks where the spacetime dimension varies with the probed scale and geometry is characterized by at least one fundamental length [Formula: see text]. In the q -derivatives scenario, one finds a tiny shift of the event horizon. Schwarzschild black holes can present an additional ring singularity, not present in general relativity, whose radius is proportional to [Formula: see text]. In the multi-fractional theory with weighted derivatives, there is no such deformation, but non-trivial geometric features generate a cosmological-constant term, leading to a de Sitter-Schwarzschild black hole. For both scenarios, we compute the Hawking temperature and comment on the resulting black-hole thermodynamics. In the case with q -derivatives, black holes can be hotter than usual and possess an additional ring singularity, while in the case with weighted derivatives they have a de Sitter hair of purely geometric origin, which may lead to a solution of the cosmological constant problem similar to that in unimodular gravity. Finally, we compare our findings with other Lorentz-violating models.

ABC of multi-fractal spacetimes and fractional sea turtles

Science.gov (United States)

Calcagni, Gianluca

2016-04-01

We clarify what it means to have a spacetime fractal geometry in quantum gravity and show that its properties differ from those of usual fractals. A weak and a strong definition of multi-scale and multi-fractal spacetimes are given together with a sketch of the landscape of multi-scale theories of gravitation. Then, in the context of the fractional theory with q-derivatives, we explore the consequences of living in a multi-fractal spacetime. To illustrate the behavior of a non-relativistic body, we take the entertaining example of a sea turtle. We show that, when only the time direction is fractal, sea turtles swim at a faster speed than in an ordinary world, while they swim at a slower speed if only the spatial directions are fractal. The latter type of geometry is the one most commonly found in quantum gravity. For time-like fractals, relativistic objects can exceed the speed of light, but strongly so only if their size is smaller than the range of particle-physics interactions. We also find new results about log-oscillating measures, the measure presentation and their role in physical observations and in future extensions to nowhere-differentiable stochastic spacetimes.

Drugs and Mental Health Problems among the Roma: Protective Factors Promoted by the Iglesia Evangélica Filadelfia

Directory of Open Access Journals (Sweden)

Jelen Amador López

2018-02-01

Full Text Available Background: High incidences of drug consumption and mental health problems are found among the Roma population in Spain, a reality that remains understudied. Past studies have indicated the positive role played by the Iglesia Evangélica Filadelfia (IEF in promoting rehabilitation and prevention of these practices. Objective: In this article, authors analyze in which ways the IEF favors processes of drug rehabilitation and mental health recovery as well as the prevention of these problems among its Roma members. Methods: A communicative qualitative approach was developed. It was communicative because new knowledge was created by dialogically contrasting the existing state of the art with study participants. It was qualitative because everyday life stories were collected, gathering the experiences, perceptions and interpretations of Roma people who are actively involved in three different IEF churches based in Barcelona. Results: This article identifies these protective factors: anti-drug discourse, a supportive environment, new social relations, role model status, the promotion of interactions, the revaluation of oneself, spiritual activities and the improvement of the feeling of belonging and the creation of meaning. Conclusion: The present research contributes new evidence to the current understanding of the role played by the IEF in improving Roma health status and how the identified protective factors can contribute to rehabilitation and recovery from such problems in other contexts.

Drugs and Mental Health Problems among the Roma: Protective Factors Promoted by the Iglesia Evangélica Filadelfia.

Science.gov (United States)

López, Jelen Amador; García, Ramón Flecha; Martí, Teresa Sordé

2018-02-14

Background: High incidences of drug consumption and mental health problems are found among the Roma population in Spain, a reality that remains understudied. Past studies have indicated the positive role played by the Iglesia Evangélica Filadelfia (IEF) in promoting rehabilitation and prevention of these practices. Objective: In this article, authors analyze in which ways the IEF favors processes of drug rehabilitation and mental health recovery as well as the prevention of these problems among its Roma members. Methods: A communicative qualitative approach was developed. It was communicative because new knowledge was created by dialogically contrasting the existing state of the art with study participants. It was qualitative because everyday life stories were collected, gathering the experiences, perceptions and interpretations of Roma people who are actively involved in three different IEF churches based in Barcelona. Results: This article identifies these protective factors: anti-drug discourse, a supportive environment, new social relations, role model status, the promotion of interactions, the revaluation of oneself, spiritual activities and the improvement of the feeling of belonging and the creation of meaning. Conclusion: The present research contributes new evidence to the current understanding of the role played by the IEF in improving Roma health status and how the identified protective factors can contribute to rehabilitation and recovery from such problems in other contexts.

Assessment of 48 Stock markets using adaptive multifractal approach

Science.gov (United States)

Ferreira, Paulo; Dionísio, Andreia; Movahed, S. M. S.

2017-11-01

In this paper, Stock market comovements are examined using cointegration, Granger causality tests and nonlinear approaches in context of mutual information and correlations. Since underlying data sets are affected by non-stationarities and trends, we also apply Adaptive Multifractal Detrended Fluctuation Analysis (AMF-DFA) and Adaptive Multifractal Detrended Cross-Correlation Analysis (AMF-DXA). We find only 170 pair of Stock markets cointegrated, and according to the Granger causality and mutual information, we realize that the strongest relations lies between emerging markets, and between emerging and frontier markets. According to scaling exponent given by AMF-DFA, h(q = 2) > 1, we find that all underlying data sets belong to non-stationary process. According to Efficient Market Hypothesis (EMH), only 8 markets are classified in uncorrelated processes at 2 σ confidence interval. 6 Stock markets belong to anti-correlated class and dominant part of markets has memory in corresponding daily index prices during January 1995 to February 2014. New-Zealand with H = 0 . 457 ± 0 . 004 and Jordan with H = 0 . 602 ± 0 . 006 are far from EMH. The nature of cross-correlation exponents based on AMF-DXA is almost multifractal for all pair of Stock markets. The empirical relation, Hxy ≤ [Hxx +Hyy ] / 2, is confirmed. Mentioned relation for q > 0 is also satisfied while for q behavior of markets for small fluctuations is affected by contribution of major pair. For larger fluctuations, the cross-correlation contains information from both local (internal) and global (external) conditions. Width of singularity spectrum for auto-correlation and cross-correlation are Δαxx ∈ [ 0 . 304 , 0 . 905 ] and Δαxy ∈ [ 0 . 246 , 1 . 178 ] , respectively. The wide range of singularity spectrum for cross-correlation confirms that the bilateral relation between Stock markets is more complex. The value of σDCCA indicates that all pairs of stock market studied in this time interval

Roma in Slovakia – silent and invisible minority (Social Networking and Pastoral Pentecostal Discourse as a case of giving voice and positive visibility

Directory of Open Access Journals (Sweden)

Tatiana Podolinská

2017-06-01

Full Text Available The contribution is meant to be a micro-case study to the issue of institutional production and reproduction of security of a selected minority group in Slovakia, through tracing the process of social networking and re-construction of the (ethnic identity on a religious basis. Principal attention is paid to the analysis of the transsocial and trans-ethnic discourse and the concept of New Roma as a de-ethnicised and ahistorically constructed label with positive and non-ascriptive connotations. The Pentecostal concept of the Family of God is studied in connection with the perception of the increased feeling of security not only within primary (family networks, but also within hybrid (religion-based networks. The New Roma concept offered to Roma by pastors would increase the potential of Roma to enter also secondary (professional and other kinds of networks within the mainstream society and allow them positive visibility at the mezzo-level of society. The new forms of social networking hand in hand with the new concept of de-ethnicised and deessentialised identity would allow Roma to change the management techniques from making security through invisibility to a more emancipative and assertive technique employing the paradigm “more visible = more secure”. The author points out the forced ethnicisation of the categories of Rom and Roma nation at the level of the practical discourse. From this point of view, the traditional type of ethnicity (based on traditional definitions of the nationis often intentionally over-communicated. Both ethnicisation (excessive accentuation of the ethnic perspective and de-ethnicisation (itsintentional suppression usually serve as practical (political tools for an objective fixing of the unfavourable position of Roma ethnic minority.This may produce a strong feeling of cultural hostility and insecurity on “both sides”. The author picks up the cases from practice and turns attention to the analysis of the

Multiscale multifractal multiproperty analysis of financial time series based on Rényi entropy

Science.gov (United States)

Yujun, Yang; Jianping, Li; Yimei, Yang

This paper introduces a multiscale multifractal multiproperty analysis based on Rényi entropy (3MPAR) method to analyze short-range and long-range characteristics of financial time series, and then applies this method to the five time series of five properties in four stock indices. Combining the two analysis techniques of Rényi entropy and multifractal detrended fluctuation analysis (MFDFA), the 3MPAR method focuses on the curves of Rényi entropy and generalized Hurst exponent of five properties of four stock time series, which allows us to study more universal and subtle fluctuation characteristics of financial time series. By analyzing the curves of the Rényi entropy and the profiles of the logarithm distribution of MFDFA of five properties of four stock indices, the 3MPAR method shows some fluctuation characteristics of the financial time series and the stock markets. Then, it also shows a richer information of the financial time series by comparing the profile of five properties of four stock indices. In this paper, we not only focus on the multifractality of time series but also the fluctuation characteristics of the financial time series and subtle differences in the time series of different properties. We find that financial time series is far more complex than reported in some research works using one property of time series.

Aging in autonomic control by multifractal studies of cardiac interbeat intervals in the VLF band

International Nuclear Information System (INIS)

Makowiec, Danuta; Kryszewski, Stanisław; Rynkiewicz, Andrzej; Wdowczyk-Szulc, Joanna; Żarczyńska-Buchowiecka, Marta; Gałąska, Rafał

2011-01-01

The heart rate responds dynamically to various intrinsic and environmental stimuli. The autonomic nervous system is said to play a major role in this response. Multifractal analysis offers a novel method to assess the response of cardiac interbeat intervals. Twenty-four hour ECG recordings of RR interbeat intervals (of 48 elderly volunteers (age 65–94), 40 middle-aged persons (age 45–53) and 36 young adults (age 18–26)) were investigated to study the effect of aging on autonomic regulation during normal activity in healthy adults. Heart RR-interval variability in the very low frequency (VLF) band (32–420 RR intervals) was evaluated by multifractal tools. The nocturnal and diurnal signals of 6 h duration were studied separately. For each signal, the analysis was performed twice: for a given signal and for the integrated signal. A multifractal spectrum was quantified by the h max value at which a multifractal spectrum attained its maximum, width of a spectrum, Hurst exponent, extreme events h left and distance between the maxima of a signal and its integrated counterpart. The following seven characteristics are suggested as quantifying the age-related decrease in the autonomic function ('int' refers to the integrated signal): (a) h sleep max − h max wake > 0.05 for a signal; (b) h int max > 1.15 for wake; (c) h int max − h max > 0.85 for sleep; (d) Hurst wake − Hurst sleep < 0.01; (e) width wake > 0.07; (f) width int < 0.30 for sleep; (g) h int left > 0.75. Eighty-one percent of elderly people had at least four of these properties, and ninety-two percent of young people had three or less. This shows that the multifractal approach offers a concise and reliable index of healthy aging for each individual. Additionally, the applied method yielded insights into dynamical changes in the autonomic regulation due to the circadian cycle and aging. Our observations support the hypothesis that imbalance in the autonomic control due to healthy aging could

Health Roma children. Biological conditions [Zdrowie romskich dzieci. Uwarunkowania biologiczne

OpenAIRE

Mirosław ZDULSKI

2017-01-01

The paper presents the results of studies on the incidence of biologically (genetically) determined illnesses such as congenital eye disease (glaucoma), phenylketonuria, congenital hypothyrodism, congenital skull deformity and some cases of mental retardation among Roma children living in Slovakia and the Czech Republic. The problem that causes the biggest disputes is the considerable percentage of disabilities, particularly mental ones, registered in this population, which exceeds manyfold t...

Ethnic, Familial, and Religious Identity of Roma Adolescents in Bulgaria, Czech Republic, Kosovo, and Romania in Relation to Their Level of Well-Being

NARCIS (Netherlands)

Dimitrova, Radosveta; van de Vijver, Fons J. R.; Tausova, Jitka; Chasiotis, Athanasios; Bender, Michael; Buzea, Carmen; Uka, Fitim; Tair, Ergyul

2017-01-01

This study examines ethnic, national, familial, and religious identity and well-being of 632 Roma minority and 589 majority adolescents (age: M = 15.98 years, SD = 1.34) in Bulgaria, the Czech Republic, Kosovo, and Romania. Results indicated that Roma showed lower endorsement of national identity

Dynamics of chaotic maps for modelling the multifractal spectrum of human brain Diffusion Tensor Images

International Nuclear Information System (INIS)

Provata, A.; Katsaloulis, P.; Verganelakis, D.A.

2012-01-01

Highlights: ► Calculation of human brain multifractal spectra. ► Calculations are based on Diffusion Tensor MRI Images. ► Spectra are modelled by coupled Ikeda map dynamics. ► Coupled lattice Ikeda maps model well only positive multifractal spectra. ► Appropriately modified coupled lattice Ikeda maps give correct spectra. - Abstract: The multifractal spectra of 3d Diffusion Tensor Images (DTI) obtained by magnetic resonance imaging of the human brain are studied. They are shown to deviate substantially from artificial brain images with the same white matter intensity. All spectra, obtained from 12 healthy subjects, show common characteristics indicating non-trivial moments of the intensity. To model the spectra the dynamics of the chaotic Ikeda map are used. The DTI multifractal spectra for positive q are best approximated by 3d coupled Ikeda maps in the fully developed chaotic regime. The coupling constants are as small as α = 0.01. These results reflect not only the white tissue non-trivial architectural complexity in the human brain, but also demonstrate the presence and importance of coupling between neuron axons. The architectural complexity is also mirrored by the deviations in the negative q-spectra, where the rare events dominate. To obtain a good agreement in the DTI negative q-spectrum of the brain with the Ikeda dynamics, it is enough to slightly modify the most rare events of the coupled Ikeda distributions. The representation of Diffusion Tensor Images with coupled Ikeda maps is not unique: similar conclusions are drawn when other chaotic maps (Tent, Logistic or Henon maps) are employed in the modelling of the neuron axons network.

[Expectations and user experiences of older Roma women with health services in primary care].

Science.gov (United States)

Ramos-Morcillo, Antonio Jesús; Ruzafa-Martínez, María; Fernández-Salazar, Serafín; Del-Pino-Casado, Rafael

2015-04-01

To know the expectations and user experiences of older Roma women with health services in primary care (PC). Phenomenological qualitative study. Using focus groups (4-9 women/group) and semistructured interviews. Audio recorded from March to November 2011. Performed in Úbeda and Linares (Spain). Roma women over 50years. A purposive sample stratified by age and area of residence was carried out. Woman were recruited through community leaders. Process of qualitative content analysis: coding, triangulation, obtain and verify results. Supported whit the software Nvivo 8. Three focus groups and four interviews were conducted, including 23 women. The expectations for the PC are focus exclusively on their physician, being invisible other professionals. They look for a relationship with their physician based on trust. In their user experience with the PC coexist three types of user: who goes to their appointments, demands attention only in acute disease and does not attend appointments and reviews. There are socio-cultural factors related to accessibility. Older Roma women set their expectations and experiences with health service in PC around the binomial disease/physician. Expect attention based on trust and a high instrumentalization. A speech with signs of change directed towards a more active and demanding participation in PC services is observed. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Multifractal Detrended Fluctuation Analysis of alpha and theta EEG rhythms with musical stimuli

International Nuclear Information System (INIS)

Maity, Akash Kumar; Pratihar, Ruchira; Mitra, Anubrato; Dey, Subham; Agrawal, Vishal; Sanyal, Shankha; Banerjee, Archi; Sengupta, Ranjan; Ghosh, Dipak

2015-01-01

Highlights: • EEG was done to record the brain electrical activity of 10 subjects in response to simple acoustical tanpura stimuli. • Empirical Mode Decomposition (EMD) technique used to make the EEG signal free from blink and other muscular artifacts. • Multifractal Detrended Fluctuation Analysis (MFDFA) performed to assess the complexity of extracted alpha and theta brain rhythms. • The findings show spectral width i.e. complexity of alpha and theta rhythms increase in all the seven frontal locations studied, under the effect of musical stimuli. - Abstract: Electroencephalography (EEG) was performed on 10 participants using a simple acoustical stimuli i.e. a tanpura drone. The tanpura drone is free from any semantic content and is used with a hypothesis that it provides a specific resting environment for the listeners. The EEG data was extracted for all the frontal electrodes viz. F3, F4, F7, F8, Fp1, Fp2 and Fz. Empirical Mode Decomposition (EMD) was applied on the acquired raw EEG signal to make it free from blink as well as other muscular artifacts. Wavelet Transform (WT) technique was used to segregate alpha and theta waves from the denoised EEG signal. Non-linear analysis in the form of Multifractal Detrended Fluctuation Analysis (MFDFA) was carried out on the extracted alpha and theta time series data to study the variation of their complexity. It was found that in all the frontal electrodes alpha as well as theta complexity increases as is evident from the increase of multifractal spectral width. This study is entirely new and gives interesting data regarding neural activation of the alpha and theta brain rhythms while listening to simple acoustical stimuli. The importance of this study lies in the context of emotion quantification using multifractal spectral width as a parameter as well as in the field of cognitive music therapy. The results are discussed in detail.

Edifícios de espetáculos em Roma

Directory of Open Access Journals (Sweden)

Maria Luiza Corassin

1997-12-01

Full Text Available O espaço urbano de Roma. Os diferentes tipos de espetáculos requeriam construções especializadas: estádios, circos e anfiteatros. Domiciano construiu o Estádio para o Agon Capitolinus, hoje Praça Navona; o Circo Máximo, o anfiteatro Flávio e o Stadium Domitiani tornaram-se símbolos do poderio romano e local de integração dos grupos sociais do Imperio.

New trends in applied harmonic analysis sparse representations, compressed sensing, and multifractal analysis

CERN Document Server

Cabrelli, Carlos; Jaffard, Stephane; Molter, Ursula

2016-01-01

This volume is a selection of written notes corresponding to courses taught at the CIMPA School: "New Trends in Applied Harmonic Analysis: Sparse Representations, Compressed Sensing and Multifractal Analysis". New interactions between harmonic analysis and signal and image processing have seen striking development in the last 10 years, and several technological deadlocks have been solved through the resolution of deep theoretical problems in harmonic analysis. New Trends in Applied Harmonic Analysis focuses on two particularly active areas that are representative of such advances: multifractal analysis, and sparse representation and compressed sensing. The contributions are written by leaders in these areas, and covers both theoretical aspects and applications. This work should prove useful not only to PhD students and postdocs in mathematics and signal and image processing, but also to researchers working in related topics.

'It's Good Enough That Our Children Are Accepted': Roma Mothers' Views of Children's Education Post Migration

Science.gov (United States)

Sime, Daniela; Fassetta, Giovanna; McClung, Michele

2018-01-01

The discrimination of Roma groups across Europe has been highlighted by several international organisations. For many, poverty, racism and their children's systematic exclusion from education are 'push' factors when deciding to migrate. This study explores Roma mothers' views of their children's education post migration and their attitudes to…

Multifractal analysis of vertical total electron content (VTEC at equatorial region and low latitude, during low solar activity

Directory of Open Access Journals (Sweden)

M. J. A. Bolzan

2013-01-01

Full Text Available This paper analyses the multifractal aspects of the GPS data (measured during a period of low solar activity obtained from two Brazilian stations: Belém (01.3° S, 48.3° W and São José dos Campos (SJC (23.2° S, 45.9° W. The results show that the respective geographic sites show important scaling differences as well as similarities when their multifractal signatures for vertical total electron content (VTEC are compared. The f(α spectra have a narrow shape for great scales, which indicates the predominance of deterministic phenomena, such as solar rotation (27 days over intermittent phenomena. Furthermore, the f(α spectra for both sites have a strong multifractality degree at small scales. This strong multifractality degree observed at small scales (1 to 12 h at both sites is because the ionosphere over Brazil is a non-equilibrium system. The differences found were that Belém presented a stronger multifractality at small scales (1 h to 12 h compared with SJC, particularly in 2006. The reason for this behaviour may be associated with the location of Belém, near the geomagnetic equator, where at this location the actions of X-rays, ultraviolet, and another wavelength from the Sun are more direct, strong, and constant throughout the whole year. Although the SJC site is near ionospheric equatorial anomaly (IEA peaks, this interpretation could explain the higher values found for the intermittent parameter μ for Belém compared with SJC. Belém also showed the presence of one or two flattening regions for f(α spectra at the same scales mentioned before. These differences and similarities also were interpreted in terms of the IEA content, where this phenomenon is an important source of intermittence due the presence of the VTEC peaks at ±20° geomagnetic latitudes.

Controversies about cervical cancer screening: A qualitative study of Roma women's (non)participation in cervical cancer screening in Romania.

Science.gov (United States)

Andreassen, Trude; Weiderpass, Elisabete; Nicula, Florian; Suteu, Ofelia; Itu, Andreea; Bumbu, Minodora; Tincu, Aida; Ursin, Giske; Moen, Kåre

2017-06-01

Romania has Europe's highest incidence and mortality of cervical cancer. While a free national cervical cancer-screening programme has been in operation since 2012, participation in the programme is low, particularly in minority populations. The aim of this study was to explore Roma women's (non)participation in the programme from women's own perspectives and those of healthcare providers and policy makers. We carried out fieldwork for a period of 125 days in 2015/16 involving 144 study participants in Cluj and Bucharest counties. Fieldwork entailed participant observation, qualitative interviewing and focus group discussions. A striking finding was that screening providers and Roma women had highly different takes on the national screening programme. We identified four fundamental questions about which there was considerable disagreement between them: whether a free national screening programme existed in the first place, whether Roma women were meant to be included in the programme if it did, whether Roma women wanted to take part in screening, and to what degree screening participation would really benefit women's health. On the background of insights from actor-network theory, the article discusses to what degree the programme could be said to speak to the interest of its intended Roma public, and considers the controversies in light of the literature on patient centred care and user involvement in health care. The paper contributes to the understanding of the health and health-related circumstances of the largest minority in Europe. It also problematizes the use of the concept of "barriers" in research into participation in cancer screening, and exemplifies how user involvement can potentially help transform and improve screening programmes. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Constantino y la utilización político- ideológica de Roma

Directory of Open Access Journals (Sweden)

Manuel J. RODRÍGUEZ GERVÁS

2010-02-01

Full Text Available RESUMEN: Constantino, al igual que ya hizo su antecesor Diocleciano1, no fijó su residencia en Roma, sino que, basándose fundamentalmente en principios geo-estratégicos, estableció su corte en diversas ciudades imperiales de Occidente y Oriente, para finalmente en el 330 hacer de Constantinopla la «nueva Roma». Sin embargo la antigua capital imperial, a pesar de dejar de ser el centro político-administrativo, no perdió el papel ideológico y siguió siendo considerada «reina del mundo», como afirma un panegirista. Constantino no es ajeno a dicha concepción y utiliza las tres visitas a ésta, años 312, 315 y 326, como elemento propaganístico de su política.

Diversity vs. Equality: Why the Education of Roma Children Does Not Work

Science.gov (United States)

Kyuchukov, Hristo; New, William

2016-01-01

This article takes up the question of why recent efforts to reform Roma education have been largely unsuccessful. Using case studies, the authors identify and discuss situations that have produced poor results: good intentions and bad realisations, good intentions and good realisations, and misguided intentions and bad realisations. They suggest…

Spatial Characterization of Landscapes through Multifractal Analysis of DEM

Directory of Open Access Journals (Sweden)

P. L. Aguado

2014-01-01

Full Text Available Landscape evolution is driven by abiotic, biotic, and anthropic factors. The interactions among these factors and their influence at different scales create a complex dynamic. Landscapes have been shown to exhibit numerous scaling laws, from Horton’s laws to more sophisticated scaling of heights in topography and river network topology. This scaling and multiscaling analysis has the potential to characterise the landscape in terms of the statistical signature of the measure selected. The study zone is a matrix obtained from a digital elevation model (DEM (map 10 × 10 m, and height 1 m that corresponds to homogeneous region with respect to soil characteristics and climatology known as “Monte El Pardo” although the water level of a reservoir and the topography play a main role on its organization and evolution. We have investigated whether the multifractal analysis of a DEM shows common features that can be used to reveal the underlying patterns and information associated with the landscape of the DEM mapping and studied the influence of the water level of the reservoir on the applied analysis. The results show that the use of the multifractal approach with mean absolute gradient data is a useful tool for analysing the topography represented by the DEM.

Multiplicative multifractal modeling and discrimination of human neuronal activity

International Nuclear Information System (INIS)

Zheng Yi; Gao Jianbo; Sanchez, Justin C.; Principe, Jose C.; Okun, Michael S.

2005-01-01

Understanding neuronal firing patterns is one of the most important problems in theoretical neuroscience. It is also very important for clinical neurosurgery. In this Letter, we introduce a computational procedure to examine whether neuronal firing recordings could be characterized by cascade multiplicative multifractals. By analyzing raw recording data as well as generated spike train data from 3 patients collected in two brain areas, the globus pallidus externa (GPe) and the globus pallidus interna (GPi), we show that the neural firings are consistent with a multifractal process over certain time scale range (t 1 ,t 2 ), where t 1 is argued to be not smaller than the mean inter-spike-interval of neuronal firings, while t 2 may be related to the time that neuronal signals propagate in the major neural branching structures pertinent to GPi and GPe. The generalized dimension spectrum D q effectively differentiates the two brain areas, both intra- and inter-patients. For distinguishing between GPe and GPi, it is further shown that the cascade model is more effective than the methods recently examined by Schiff et al. as well as the Fano factor analysis. Therefore, the methodology may be useful in developing computer aided tools to help clinicians perform precision neurosurgery in the operating room

PageRank of integers

International Nuclear Information System (INIS)

Frahm, K M; Shepelyansky, D L; Chepelianskii, A D

2012-01-01

We up a directed network tracing links from a given integer to its divisors and analyze the properties of the Google matrix of this network. The PageRank vector of this matrix is computed numerically and it is shown that its probability is approximately inversely proportional to the PageRank index thus being similar to the Zipf law and the dependence established for the World Wide Web. The spectrum of the Google matrix of integers is characterized by a large gap and a relatively small number of nonzero eigenvalues. A simple semi-analytical expression for the PageRank of integers is derived that allows us to find this vector for matrices of billion size. This network provides a new PageRank order of integers. (paper)

Change in ranking order of prescribing patterns by age and sex standardization of the practice population--audit may be misleading

DEFF Research Database (Denmark)

Olesen, Frede; Vedsted, Peter; Nielsen, Jørgen Nørskov

1996-01-01

on the age, sex, and numbers of patients per practice was also obtained. The direct standardization method was used to adjust practice populations for age and sex. SETTING: The town of Randers, Aarhus County, Denmark. SUBJECTS: 35 practices, 41 GPs. MAIN OUTCOME MEASURES: Ranking of the 35 practices......OBJECTIVE: To demonstrate whether standardization of practice populations by age and sex changes the internal prescription ranking order of a group of practices. DESIGN: Data on the prescribing of cardiovascular drugs in a group of practices were obtained from a county-based database. Information...

Multifractal analysis of the Korean agricultural market

Science.gov (United States)

Kim, Hongseok; Oh, Gabjin; Kim, Seunghwan

2011-11-01

We have studied the long-term memory effects of the Korean agricultural market using the detrended fluctuation analysis (DFA) method. In general, the return time series of various financial data, including stock indices, foreign exchange rates, and commodity prices, are uncorrelated in time, while the volatility time series are strongly correlated. However, we found that the return time series of Korean agricultural commodity prices are anti-correlated in time, while the volatility time series are correlated. The n-point correlations of time series were also examined, and it was found that a multifractal structure exists in Korean agricultural market prices.

Access to health care for Roma children in Central and Eastern Europe: findings from a qualitative study in Bulgaria

Directory of Open Access Journals (Sweden)

Spencer Nick J

2009-06-01

Full Text Available Abstract Background Despite the attention the situation of the Roma in Central and Eastern Europe has received in the context of European Union enlargement, research on their access to health services is very limited, in particular with regard to child health services. Methods 50 qualitative in-depth interviews with users, providers and policy-makers concerned with child health services in Bulgaria, conducted in two villages, one town of 70,000 inhabitants, and the capital Sofia. Results Our findings provide important empirical evidence on the range of barriers Roma children face when accessing health services. Among the most important barriers are poverty, administrative and geographical obstacles, low levels of parental education, and lack of ways to accommodate the cultural, linguistic and religious specifics of this population group. Conclusion Our research illustrates the complexity of the problems the Roma face. Access to health care cannot be discussed in isolation from other problems this population group experiences, such as poverty, restricted access to education, and social exclusion.

From standard alpha-stable Lévy motions to horizontal visibility networks: dependence of multifractal and Laplacian spectrum

Science.gov (United States)

Zou, Hai-Long; Yu, Zu-Guo; Anh, Vo; Ma, Yuan-Lin

2018-05-01

In recent years, researchers have proposed several methods to transform time series (such as those of fractional Brownian motion) into complex networks. In this paper, we construct horizontal visibility networks (HVNs) based on the -stable Lévy motion. We aim to study the relations of multifractal and Laplacian spectrum of transformed networks on the parameters and of the -stable Lévy motion. First, we employ the sandbox algorithm to compute the mass exponents and multifractal spectrum to investigate the multifractality of these HVNs. Then we perform least squares fits to find possible relations of the average fractal dimension , the average information dimension and the average correlation dimension against using several methods of model selection. We also investigate possible dependence relations of eigenvalues and energy on , calculated from the Laplacian and normalized Laplacian operators of the constructed HVNs. All of these constructions and estimates will help us to evaluate the validity and usefulness of the mappings between time series and networks, especially between time series of -stable Lévy motions and HVNs.

Multifractal features of spot rates in the Liquid Petroleum Gas shipping market

NARCIS (Netherlands)

Engelen, Steve; Norouzzadeh, Payam; Dullaert, Wout; Rahmani, Bahareh

We investigate for the first time the spot rate dynamics of Very Large Gas Carriers (VLGCs) by means of multifractal detrended fluctuation analysis (MF-DFA) and rescaled range (R/S) analysis. Both non-parametric methods allow for a rigorous statistical analysis of the freight process by detecting

Multifractal analysis of plasma turbulence in biasing experiments on Castor tokamak

Czech Academy of Sciences Publication Activity Database

Budaev, V.P.; Dufková, Edita; Nanobashvili, S.; Weinzettl, Vladimír; Zajac, Jaromír

2005-01-01

Roč. 55, C (2005), s. 1615-1621 ISSN 0011-4626. [Workshop “Electric Fields, Structures and Relaxation in Edge Plasmas". Tarragona, 5.7.2005-5.7.2005] Institutional research plan: CEZ:AV0Z20430508 Keywords : plasma turbulence * multifractal analysis Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.360, year: 2005

Chaos game representation of functional protein sequences, and simulation and multifractal analysis of induced measures

International Nuclear Information System (INIS)

Zu-Guo, Yu; Qian-Jun, Xiao; Long, Shi; Jun-Wu, Yu; Anh, Vo

2010-01-01

Investigating the biological function of proteins is a key aspect of protein studies. Bioinformatic methods become important for studying the biological function of proteins. In this paper, we first give the chaos game representation (CGR) of randomly-linked functional protein sequences, then propose the use of the recurrent iterated function systems (RIFS) in fractal theory to simulate the measure based on their chaos game representations. This method helps to extract some features of functional protein sequences, and furthermore the biological functions of these proteins. Then multifractal analysis of the measures based on the CGRs of randomly-linked functional protein sequences are performed. We find that the CGRs have clear fractal patterns. The numerical results show that the RIFS can simulate the measure based on the CGR very well. The relative standard error and the estimated probability matrix in the RIFS do not depend on the order to link the functional protein sequences. The estimated probability matrices in the RIFS with different biological functions are evidently different. Hence the estimated probability matrices in the RIFS can be used to characterise the difference among linked functional protein sequences with different biological functions. From the values of the D q curves, one sees that these functional protein sequences are not completely random. The D q of all linked functional proteins studied are multifractal-like and sufficiently smooth for the C q (analogous to specific heat) curves to be meaningful. Furthermore, the D q curves of the measure μ based on their CGRs for different orders to link the functional protein sequences are almost identical if q ≥ 0. Finally, the C q curves of all linked functional proteins resemble a classical phase transition at a critical point. (cross-disciplinary physics and related areas of science and technology)

Roma Hukuku’nda Gemi, Han ve Ahır İşletenlerin Receptum Sorumluluğu

OpenAIRE

YEŞİLLER, Mehmet

2013-01-01

Çalışmamızda Roma Hukuku'nda gemi, han ve ahır işleten kimselerin sorumluluklarına ilişkin düzenlemeler ele alınmıştır. Roma?da özellikle gemi, han ve ahır işleten kimselerin yanlarında çalıştırdıkları kişilerin güvenilir olmamasından dolayı, taraflar arasındaki istisna sözleşmesinden kaynaklanan custodia sorumluluğuna ek olarak "actio de damno aut furto adversus nautas, caupones, stabularios ve receptum, nautae, cauponis, stabularii" sorumluluklarının düzenlendiği kaynaklardan...

INTEGRATING ROMA IN MODERN EUROPEAN SOCIETY. NEW CHALLENGES, NEW OPPORTUNITIES. AN OVERVIEW OF THEIR PAST, PRESENT AND FUTURE IN THE LIGHT OF AN ENLARGED EUROPE

Directory of Open Access Journals (Sweden)

Silviu COSTACHIE

2017-11-01

Full Text Available The Roma population, with approximately 10 million people, is the largest minority of Europe. Since the end of the communist era in Eastern Europe, mass emigration has occurred, mainly to Western Europe. Today across Western Europe the Roma still face huge problems in regard of discrimination and exclusion. A general change in the way they are perceived is necessary. In the last years, the European Union have put the Roma questions on the forefront of their discussions. Nevertheless, the situation of the minority is still very precarious and demands more concrete research and action.

The weather and Climate: emergent laws and multifractal cascades

Science.gov (United States)

Lovejoy, S.

2016-12-01

In the atmosphere, nonlinear terms are typically about a trillion times larger than linear ones; we anticipate the emergence of high level turbulence laws. The classical turbulence laws were restricted to homogeneous and isotropic systems; to apply them to the atmosphere they must be generalized to account for strong anisotropy (especially stratification) and variability (intermittency). Over the last 30 years, using scaling symmetry principles and multifractal cascades, this has been done. While hitherto they were believed applicable only up to ≈ 100 m, (generalized) turbulence laws now anisotropic and multifractal, they cover spatial scales up planetary in extent and in time well beyond weather scales to include the climate. These higher level laws are stochastic in nature and provide the theoretical basis both for stochastic parametrizations as well as stochastic forecasting. In the time domain the emergent laws for fluctuations DT (for example in temperature T) have means T > ≈ DtH i.e. they are scaling (power laws) in the time interval Dt. We find find exponents H>0 (fluctuations increase with scale) up to ≈ Dt ≈10 days (the lifetime of planetary scale structures, the analogous transition in the ocean is at Dt ≈ 1 year on Mars it is Dt ≈ 2 sols). At larger Dt, there is a transition to a new "macroweather" regime with H≈30 years (anthropocene; larger in the pre-industrial epoch), new climate processes begin to dominate, leading to H>0. "The climate is what you expect, the weather is what you get": the climate is thought to be a kind of "average weather". However this "expected" behavior is macroweather, not the climate. On the contrary, the climate is the new even lower frequency regime at scales Dt> 30 yrs and it has statistical properties very similar to the weather. At these scales, "macroweather is what you expect, the climate is what you get". The scaling in the macroweather regime implies that there is a long-term memory. We show how the

Multifractal scaling at the Kolmogorov microscale in fully developed compressible turbulence

International Nuclear Information System (INIS)

Shivamoggi, B.K.

1995-01-01

In this paper, some aspects of multifractal scaling at the Kolmogorov microscale in fully developed compressible turbulence are considered. These considerations, on the one hand, provide an insight into the mechanism of compressible turbulence, and on the other hand enable one to determine the robustness of some known results in incompressible turbulence. copyright 1995 Academic Press, Inc

The Prodigies of The Albano Lake During Roman Age and Natural Hazard Assessment At Roma, Italy.

Science.gov (United States)

Funiciello, R.; Giordano, G.; de Rita, D.

Roma is built just 20 km to the northwest of the Pleistocene Colli Albani volcano, but is believed not exposed to relevant natural hazards, except for the Tiber river flood- ings, and local amplification of seismic waves from distal earthquakes. This belief has generally induced modern historians and geologists to discard as SmythologicalT the & cedil;many references to natural prodigies that are reported by many Roman-age historians. Recent studies have demonstrated that the Albano maar, the youngest volcanic cen- tre of the Colli Albani volcano and presently filled by a 175 m deep lake, protracted its activity to the Holocene triggering several catastrophic lahar events, likely related to lake withdrawal, the deposits of which are exposed to the southwest of Roma and reach its periphery. This finding youngs the history of the volcano and makes it rele- vant to pre-historic settlements, which ScarefullyT avoided the Albano maar slopes up & cedil;to the Bronze age. What is still unknown, though, is whether the lake experienced such fluctuations and overspills during historic times. Several Roman authors such as Ti- tus Livius, Dionigi d'Alicarnasso, Plutarco, Germanico, and many others wrote about the then well known 398 BC prodigious event, when, during the war between Roma and the Etruscan city of Veio, the gods anger caused the sudden rise and overspill of the Albano lake, reported as unrelated to climatic events, and the destructive flooding of the countryside. After that event Romans actually built a tunnel-drain which still operates regulating the lake level at 293 m a.s.l., 70 m below the maar rim elevation. Should those chronicles be truthful, we can join the geologic observation of Holocene lahar deposits from lake withdrawal with historical lake withdrawals, reassessing the natural hazard for the city of Roma under a point of view never explored before. This paper carefully explores the historical credibility of the 398 BC lake overspill event and its

Analysis of heat release dynamics in an internal combustion engine using multifractals and wavelets

International Nuclear Information System (INIS)

Sen, A.K.; Litak, G.; Finney, C.E.A.; Daw, C.S.; Wagner, R.M.

2010-01-01

In this paper we analyze data from previously reported experimental measurements of cycle-to-cycle combustion variations in a lean-fueled, multi-cylinder spark-ignition (SI) engine. We characterize the changes in the observed combustion dynamics with as-fed fuel-air ratio using conventional histograms and statistical moments, and we further characterize the shifts in combustion complexity in terms of multifractals and wavelet decomposition. Changes in the conventional statistics and multifractal structure indicate trends with fuel-air ratio that parallel earlier reported observations. Wavelet decompositions reveal persistent, non-stochastic oscillation modes at higher fuel-air ratios that were not obvious in previous analyses. Recognition of these long-time-scale, non-stochastic oscillations is expected to be useful for improving modelling and control of engine combustion variations and multi-cylinder balancing.

Health-Related Quality of Life of the Roma in Greece: The Role of Socio-Economic Characteristics and Housing Conditions.

Science.gov (United States)

Pappa, Evelina; Chatzikonstantinidou, Simela; Chalkiopoulos, George; Papadopoulos, Angelos; Niakas, Dimitris

2015-06-12

The aim was to assess the health-related quality of life (HRQL) of the Roma and further to detect the significant determinants that are associated with their HRQL. The cross-sectional study involved 1068 Roma adults living in settlements (mean age 36). HRQL was measured by the Greek version of SF-36 Health Survey and further socio-demographic characteristics (sex, age, marital status, education, permanent occupation etc.) and housing conditions (stable housing, access to basic amenities such as drinkable water, drainage, electricity which compose material deprivation) were involved. Non parametric tests and multiple linear regression models were applied to identify the factors that have significant association with HRQL. After controlling for socio-demographic characteristics, health status and housing conditions, sex, age, education, chronic diseases, stable housing and material deprivation were found to be significant determinants of the Roma's HRQL. Men reported significantly better health than women as well as those who attended school compared to the illiterate. Chronic diseases were remarkably associated with poor HRQL from 10 units in MH (Mental Health) to 34 units in RP (Role Physical). Material deprivation was related to lower GH (General Health), and VT (Vitality) scores and higher RP (Role Physical) and RE (Role Emotional) scores. Chronic conditions and illiteracy are two key areas that contribute significantly to worse HRQL. Policies should be part of a comprehensive and holistic strategy for the Roma through intervention to education, housing and public health.

Multifractal analysis of real and imaginary movements: EEG study

Science.gov (United States)

Pavlov, Alexey N.; Maksimenko, Vladimir A.; Runnova, Anastasiya E.; Khramova, Marina V.; Pisarchik, Alexander N.

2018-04-01

We study abilities of the wavelet-based multifractal analysis in recognition specific dynamics of electrical brain activity associated with real and imaginary movements. Based on the singularity spectra we analyze electroencephalograms (EEGs) acquired in untrained humans (operators) during imagination of hands movements, and show a possibility to distinguish between the related EEG patterns and the recordings performed during real movements or the background electrical brain activity. We discuss how such recognition depends on the selected brain region.

Exploring Attitude Transformation: A Grounded Theory Study of Romanian Teachers of Roma Students

Science.gov (United States)

Jones, Laura Estella

2016-01-01

The purpose of this systematic grounded theory study was to explore the process of change in teacher attitudes toward including Roma ("Gypsy") students in non-segregated schools in Romania. The theories guiding this study included Mezirow's (1991, 2000) theory of transformation, Gay's (2002, 2013) theory of culturally responsive…

Health Roma children. Biological conditions [Zdrowie romskich dzieci. Uwarunkowania biologiczne

Directory of Open Access Journals (Sweden)

Mirosław ZDULSKI

2017-11-01

Full Text Available The paper presents the results of studies on the incidence of biologically (genetically determined illnesses such as congenital eye disease (glaucoma, phenylketonuria, congenital hypothyrodism, congenital skull deformity and some cases of mental retardation among Roma children living in Slovakia and the Czech Republic. The problem that causes the biggest disputes is the considerable percentage of disabilities, particularly mental ones, registered in this population, which exceeds manyfold their occurrence in the entire populations of the two countries.

Generalized Reduced Rank Tests using the Singular Value Decomposition

NARCIS (Netherlands)

F.R. Kleibergen (Frank); R. Paap (Richard)

2003-01-01

textabstractWe propose a novel statistic to test the rank of a matrix. The rank statistic overcomes deficiencies of existing rank statistics, like: necessity of a Kronecker covariance matrix for the canonical correlation rank statistic of Anderson (1951), sensitivity to the ordering of the variables

Generalized reduced rank tests using the singular value decomposition

NARCIS (Netherlands)

Kleibergen, F.R.; Paap, R.

2002-01-01

We propose a novel statistic to test the rank of a matrix. The rank statistic overcomes deficiencies of existing rank statistics, like: necessity of a Kronecker covariance matrix for the canonical correlation rank statistic of Anderson (1951), sensitivity to the ordering of the variables for the LDU

Frequency of adult type-associated lactase persistence LCT-13910C/T genotypes in the Czech/Slav and Czech Roma/Gypsy populations

Directory of Open Access Journals (Sweden)

Jaroslav A. Hubácek

2017-05-01

Full Text Available Abstract Lactase non-persistence (leading to primary lactose intolerance is a genetically dependent inability to digest lactose in adulthood. As part of the human adaptation to dairying, the human lactase LCT-13910C/T mutation (which propagates adult expression of lactase developed, spread and participated in the adaptation to dairying. This variant is associated with lactase activity persistence, and its carriers are able to digest lactose. We compared the frequencies of lactase 13910C/T (rs4988235 genotypes in Czechs/Slavs (N = 288 and Czech Gypsies/Roma (N = 300, two ethnically different groups where this polymorphism has not yet been analysed. Allelic frequencies significantly differed between the populations (p < 0.0001. In Czechs/Slavs, the lactase persistence T allele was present in 76% of the individuals, which is in agreement with frequencies among geographically neighbouring populations. In the Czech Gypsy/Roma population, only 27% of the adults were carriers of at least one lactase persistence allele, similar to the Indian population. In agreement with this result, dairy product consumption was reported by 70.5% of Czechs/Slavs and 39.0% of the Czech Gypsy/Roma population. Both in the Czech Gypsy/Roma and in the Czech/Slavs populations, the presence of carriers of the lactase persistence allele was similar in subjects self-reporting the consumption of unfermented/fresh milk, in comparison to the others.

Stories with and about wall carpets. An anthropological account on the inhabitation of Ursari Romanian Roma

Directory of Open Access Journals (Sweden)

Andreea Racleş

2014-12-01

Full Text Available The aim of this paper is to discuss the ways in which objects assist us in telling small stories about our positions in relation to our inhabited space, but also in relation to perceived dichotomised categories like us-others, the modern-the outmoded, civilized-backward. Acknowledging that narratives emerge from interactions between people, this paper is an attempt to show that an important role in the emergence of stories is played by interactions between people and objects. The wall carpets hung by Ursari Roma from a north-eastern Romanian town and the stories developed with and about these items constitute the main focus of this analysis. From an anthropological and material culture perspective, wall carpets are discussed as material presences in storytelling events and as objects of experience-centred stories that assist Roma people in negotiating and enacting their identities and belongings. Taking a cue from Georgakopoulou, who argues that narratives count on both discourses and activities (2007, home making practices and domestic activities (such as those related to the maintenance of the wall carpets are essential to this paper, as they enable an understanding of the “performative narrative of daily life” (Langellier 2004. The analysis is based on ethnographic material collected in 2014 in the aforementioned community, while the unit of analysis consists of excerpts from discussions with two Roma families, which became storytelling episodes.

A model-based approach to operational event groups ranking

Energy Technology Data Exchange (ETDEWEB)

Simic, Zdenko [European Commission Joint Research Centre, Petten (Netherlands). Inst. for Energy and Transport; Maqua, Michael [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Koeln (Germany); Wattrelos, Didier [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France)

2014-04-15

The operational experience (OE) feedback provides improvements in all industrial activities. Identification of the most important and valuable groups of events within accumulated experience is important in order to focus on a detailed investigation of events. The paper describes the new ranking method and compares it with three others. Methods have been described and applied to OE events utilised by nuclear power plants in France and Germany for twenty years. The results show that different ranking methods only roughly agree on which of the event groups are the most important ones. In the new ranking method the analytical hierarchy process is applied in order to assure consistent and comprehensive weighting determination for ranking indexes. The proposed method allows a transparent and flexible event groups ranking and identification of the most important OE for further more detailed investigation in order to complete the feedback. (orig.)

Multifractal analysis for the historic set in topological dynamical systems

International Nuclear Information System (INIS)

Zhou, Xiaoyao; Chen, Ercai

2013-01-01

In this paper the historic set is divided into different level sets and we use topological pressure to describe the size of these level sets. We give an application of these results to dimension theory. Our primary focus is using topological pressure to describe the relative multifractal spectrum of ergodic averages and to give a positive answer to the conjecture posed by Olsen (2003 J. Math. Pures Appl. 82 1591–649). (paper)

Germany's Other Others: Teaching About Kurds, Roma, and Sinti in an Upper-Division Culture Class.

Science.gov (United States)

Zinn, Gesa

2000-01-01

Argues for the expansion of the German culture classroom by incorporating materials about the Roma and Sinti, and Kurds. Suggests valuable resources and materials for German instructors and discusses teaching strategies that combine teaching cultural content and language proficiency. (Author/VWL)

A Case-Based Reasoning Method with Rank Aggregation

Science.gov (United States)

Sun, Jinhua; Du, Jiao; Hu, Jian

2018-03-01

In order to improve the accuracy of case-based reasoning (CBR), this paper addresses a new CBR framework with the basic principle of rank aggregation. First, the ranking methods are put forward in each attribute subspace of case. The ordering relation between cases on each attribute is got between cases. Then, a sorting matrix is got. Second, the similar case retrieval process from ranking matrix is transformed into a rank aggregation optimal problem, which uses the Kemeny optimal. On the basis, a rank aggregation case-based reasoning algorithm, named RA-CBR, is designed. The experiment result on UCI data sets shows that case retrieval accuracy of RA-CBR algorithm is higher than euclidean distance CBR and mahalanobis distance CBR testing.So we can get the conclusion that RA-CBR method can increase the performance and efficiency of CBR.

Multifractal analysis of 2D gray soil images

Science.gov (United States)

González-Torres, Ivan; Losada, Juan Carlos; Heck, Richard; Tarquis, Ana M.

2015-04-01

Soil structure, understood as the spatial arrangement of soil pores, is one of the key factors in soil modelling processes. Geometric properties of individual and interpretation of the morphological parameters of pores can be estimated from thin sections or 3D Computed Tomography images (Tarquis et al., 2003), but there is no satisfactory method to binarized these images and quantify the complexity of their spatial arrangement (Tarquis et al., 2008, Tarquis et al., 2009; Baveye et al., 2010). The objective of this work was to apply a multifractal technique, their singularities (α) and f(α) spectra, to quantify it without applying any threshold (Gónzalez-Torres, 2014). Intact soil samples were collected from four horizons of an Argisol, formed on the Tertiary Barreiras group of formations in Pernambuco state, Brazil (Itapirema Experimental Station). The natural vegetation of the region is tropical, coastal rainforest. From each horizon, showing different porosities and spatial arrangements, three adjacent samples were taken having a set of twelve samples. The intact soil samples were imaged using an EVS (now GE Medical. London, Canada) MS-8 MicroCT scanner with 45 μm pixel-1 resolution (256x256 pixels). Though some samples required paring to fit the 64 mm diameter imaging tubes, field orientation was maintained. References Baveye, P.C., M. Laba, W. Otten, L. Bouckaert, P. Dello, R.R. Goswami, D. Grinev, A. Houston, Yaoping Hu, Jianli Liu, S. Mooney, R. Pajor, S. Sleutel, A. Tarquis, Wei Wang, Qiao Wei, Mehmet Sezgin. Observer-dependent variability of the thresholding step in the quantitative analysis of soil images and X-ray microtomography data. Geoderma, 157, 51-63, 2010. González-Torres, Iván. Theory and application of multifractal analysis methods in images for the study of soil structure. Master thesis, UPM, 2014. Tarquis, A.M., R.J. Heck, J.B. Grau; J. Fabregat, M.E. Sanchez and J.M. Antón. Influence of Thresholding in Mass and Entropy Dimension of 3-D

A multifractal approach to characterize cumulative rainfall and tillage effects on soil surface micro-topography and to predict depression storage

Directory of Open Access Journals (Sweden)

E. Vidal Vázquez

2010-10-01

Full Text Available Most of the indices currently employed for assessing soil surface micro-topography, such as random roughness (RR, are merely descriptors of its vertical component. Recently, multifractal analysis provided a new insight for describing the spatial configuration of soil surface roughness. The main objective of this study was to test the ability of multifractal parameters to assess in field conditions the decay of initial surface roughness induced by natural rainfall under different soil tillage systems. In addition, we evaluated the potential of the joint use of multifractal indices plus RR to improve predictions of water storage in depressions of the soil surface (MDS. Field experiments were performed on an Oxisol at Campinas, São Paulo State (Brazil. Six tillage treatments, namely, disc harrow, disc plough, chisel plough, disc harrow + disc level, disc plough + disc level and chisel plough + disc level were tested. In each treatment soil surface micro-topography was measured four times, with increasing amounts of natural rainfall, using a pin meter. The sampling scheme was a square grid with 25 × 25 mm point spacing and the plot size was 1350 × 1350 mm (≈1.8 m², so that each data set consisted of 3025 individual elevation points. Duplicated measurements were taken per treatment and date, yielding a total of 48 experimental data sets. MDS was estimated from grid elevation data with a depression-filling algorithm. Multifractal analysis was performed for experimental data sets as well as for oriented and random surface conditions obtained from the former by removing slope and slope plus tillage marks, respectively. All the investigated microplots exhibited multifractal behaviour, irrespective of surface condition, but the degree of multifractality showed wide differences between them. Multifractal parameters provided valuable information for characterizing the spatial features of soil micro-topography as they were able to

Multifractal distribution of spike intervals for two oscillators coupled by unreliable pulses

International Nuclear Information System (INIS)

Kestler, Johannes; Kinzel, Wolfgang

2006-01-01

Two neurons coupled by unreliable synapses are modelled by leaky integrate-and-fire neurons and stochastic on-off synapses. The dynamics is mapped to an iterated function system. Numerical calculations yield a multifractal distribution of interspike intervals. The covering, information and correlation dimensions are calculated as a function of synaptic strength and transmission probability. (letter to the editor)

Monofractal or multifractal: a case study of spatial distribution of mining-induced seismic activity

Directory of Open Access Journals (Sweden)

M. Eneva

1994-01-01

Full Text Available Using finite data sets and limited size of study volumes may result in significant spurious effects when estimating the scaling properties of various physical processes. These effects are examined with an example featuring the spatial distribution of induced seismic activity in Creighton Mine (northern Ontario, Canada. The events studied in the present work occurred during a three-month period, March-May 1992, within a volume of approximate size 400 x 400 x 180 m3. Two sets of microearthquake locations are studied: Data Set 1 (14,338 events and Data Set 2 (1654 events. Data Set 1 includes the more accurately located events and amounts to about 30 per cent of all recorded data. Data Set 2 represents a portion of the first data set that is formed by the most accurately located and the strongest microearthquakes. The spatial distribution of events in the two data sets is examined for scaling behaviour using the method of generalized correlation integrals featuring various moments q. From these, generalized correlation dimensions are estimated using the slope method. Similar estimates are made for randomly generated point sets using the same numbers of events and the same study volumes as for the real data. Uniform and monofractal random distributions are used for these simulations. In addition, samples from the real data are randomly extracted and the dimension spectra for these are examined as well. The spectra for the uniform and monofractal random generations show spurious multifractality due only to the use of finite numbers of data points and limited size of study volume. Comparing these with the spectra of dimensions for Data Set 1 and Data Set 2 allows us to estimate the bias likely to be present in the estimates for the real data. The strong multifractality suggested by the spectrum for Data Set 2 appears to be largely spurious; the spatial distribution, while different from uniform, could originate from a monofractal process. The spatial

Spatial and radiometric characterization of multi-spectrum satellite images through multi-fractal analysis

Science.gov (United States)

Alonso, Carmelo; Tarquis, Ana M.; Zúñiga, Ignacio; Benito, Rosa M.

2017-03-01

Several studies have shown that vegetation indexes can be used to estimate root zone soil moisture. Earth surface images, obtained by high-resolution satellites, presently give a lot of information on these indexes, based on the data of several wavelengths. Because of the potential capacity for systematic observations at various scales, remote sensing technology extends the possible data archives from the present time to several decades back. Because of this advantage, enormous efforts have been made by researchers and application specialists to delineate vegetation indexes from local scale to global scale by applying remote sensing imagery. In this work, four band images have been considered, which are involved in these vegetation indexes, and were taken by satellites Ikonos-2 and Landsat-7 of the same geographic location, to study the effect of both spatial (pixel size) and radiometric (number of bits coding the image) resolution on these wavelength bands as well as two vegetation indexes: the Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI). In order to do so, a multi-fractal analysis of these multi-spectral images was applied in each of these bands and the two indexes derived. The results showed that spatial resolution has a similar scaling effect in the four bands, but radiometric resolution has a larger influence in blue and green bands than in red and near-infrared bands. The NDVI showed a higher sensitivity to the radiometric resolution than EVI. Both were equally affected by the spatial resolution. From both factors, the spatial resolution has a major impact in the multi-fractal spectrum for all the bands and the vegetation indexes. This information should be taken in to account when vegetation indexes based on different satellite sensors are obtained.

Ranking economic history journals

DEFF Research Database (Denmark)

Di Vaio, Gianfranco; Weisdorf, Jacob Louis

2010-01-01

This study ranks-for the first time-12 international academic journals that have economic history as their main topic. The ranking is based on data collected for the year 2007. Journals are ranked using standard citation analysis where we adjust for age, size and self-citation of journals. We also...... compare the leading economic history journals with the leading journals in economics in order to measure the influence on economics of economic history, and vice versa. With a few exceptions, our results confirm the general idea about what economic history journals are the most influential for economic...... history, and that, although economic history is quite independent from economics as a whole, knowledge exchange between the two fields is indeed going on....

Ranking Economic History Journals

DEFF Research Database (Denmark)

Di Vaio, Gianfranco; Weisdorf, Jacob Louis

This study ranks - for the first time - 12 international academic journals that have economic history as their main topic. The ranking is based on data collected for the year 2007. Journals are ranked using standard citation analysis where we adjust for age, size and self-citation of journals. We...... also compare the leading economic history journals with the leading journals in economics in order to measure the influence on economics of economic history, and vice versa. With a few exceptions, our results confirm the general idea about what economic history journals are the most influential...... for economic history, and that, although economic history is quite independent from economics as a whole, knowledge exchange between the two fields is indeed going on....

Multifractal analysis of 2001 Mw 7 . 7 Bhuj earthquake sequence in Gujarat, Western India

Science.gov (United States)

Aggarwal, Sandeep Kumar; Pastén, Denisse; Khan, Prosanta Kumar

2017-12-01

The 2001 Mw 7 . 7 Bhuj mainshock seismic sequence in the Kachchh area, occurring during 2001 to 2012, has been analyzed using mono-fractal and multi-fractal dimension spectrum analysis technique. This region was characterized by frequent moderate shocks of Mw ≥ 5 . 0 for more than a decade since the occurrence of 2001 Bhuj earthquake. The present study is therefore important for precursory analysis using this sequence. The selected long-sequence has been investigated first time for completeness magnitude Mc 3.0 using the maximum curvature method. Multi-fractal Dq spectrum (Dq ∼ q) analysis was carried out using effective window-length of 200 earthquakes with a moving window of 20 events overlapped by 180 events. The robustness of the analysis has been tested by considering the magnitude completeness correction term of 0.2 to Mc 3.0 as Mc 3.2 and we have tested the error in the calculus of Dq for each magnitude threshold. On the other hand, the stability of the analysis has been investigated down to the minimum magnitude of Mw ≥ 2 . 6 in the sequence. The analysis shows the multi-fractal dimension spectrum Dq decreases with increasing of clustering of events with time before a moderate magnitude earthquake in the sequence, which alternatively accounts for non-randomness in the spatial distribution of epicenters and its self-organized criticality. Similar behavior is ubiquitous elsewhere around the globe, and warns for proximity of a damaging seismic event in an area. OS: Please confirm math roman or italics in abs.

Digital image comparison by subtracting contextual transformations—percentile rank order differentiation

Science.gov (United States)

Wehde, M. E.

1995-01-01

The common method of digital image comparison by subtraction imposes various constraints on the image contents. Precise registration of images is required to assure proper evaluation of surface locations. The attribute being measured and the calibration and scaling of the sensor are also important to the validity and interpretability of the subtraction result. Influences of sensor gains and offsets complicate the subtraction process. The presence of any uniform systematic transformation component in one of two images to be compared distorts the subtraction results and requires analyst intervention to interpret or remove it. A new technique has been developed to overcome these constraints. Images to be compared are first transformed using the cumulative relative frequency as a transfer function. The transformed images represent the contextual relationship of each surface location with respect to all others within the image. The process of differentiating between the transformed images results in a percentile rank ordered difference. This process produces consistent terrain-change information even when the above requirements necessary for subtraction are relaxed. This technique may be valuable to an appropriately designed hierarchical terrain-monitoring methodology because it does not require human participation in the process.

Subtracting a best rank-1 approximation may increase tensor rank

NARCIS (Netherlands)

Stegeman, Alwin; Comon, Pierre

2010-01-01

It has been shown that a best rank-R approximation of an order-k tensor may not exist when R >= 2 and k >= 3. This poses a serious problem to data analysts using tensor decompositions it has been observed numerically that, generally, this issue cannot be solved by consecutively computing and

Multifractality and autoregressive processes of dry spell lengths in Europe: an approach to their complexity and predictability

Science.gov (United States)

Lana, X.; Burgueño, A.; Serra, C.; Martínez, M. D.

2017-01-01

Dry spell lengths, DSL, defined as the number of consecutive days with daily rain amounts below a given threshold, may provide relevant information about drought regimes. Taking advantage of a daily pluviometric database covering a great extension of Europe, a detailed analysis of the multifractality of the dry spell regimes is achieved. At the same time, an autoregressive process is applied with the aim of predicting DSL. A set of parameters, namely Hurst exponent, H, estimated from multifractal spectrum, f( α), critical Hölder exponent, α 0, for which f( α) reaches its maximum value, spectral width, W, and spectral asymmetry, B, permits a first clustering of European rain gauges in terms of the complexity of their DSL series. This set of parameters also allows distinguishing between time series describing fine- or smooth-structure of the DSL regime by using the complexity index, CI. Results of previous monofractal analyses also permits establishing comparisons between smooth-structures, relatively low correlation dimensions, notable predictive instability and anti-persistence of DSL for European areas, sometimes submitted to long droughts. Relationships are also found between the CI and the mean absolute deviation, MAD, and the optimum autoregressive order, OAO, of an ARIMA( p, d,0) autoregressive process applied to the DSL series. The detailed analysis of the discrepancies between empiric and predicted DSL underlines the uncertainty over predictability of long DSL, particularly for the Mediterranean region.

CHAOS EXPANSION FOR MULTIFRACTIONAL L ´EVY PROCESSES%多分数L´evy过程的混沌展开

Institute of Scientific and Technical Information of China (English)

吕学斌; 马树建

2016-01-01

In this paper, we study the chaos expansion for multifractional L´evy processes. By using the white noise analysis, we give the chaos expansion of multifractional L´evy Processes. Moreover, we derive their L´evy-Hermite transforms and Malliavin derivatives.%本文研究了多分数L´evy过程的混沌展开。利用白噪声分析方法，给出了多分数L´evy过程的混沌展开。进一步地，给出其L´evy-Hermite变换和Malliavin导数。

Universal scaling in sports ranking

International Nuclear Information System (INIS)

Deng Weibing; Li Wei; Cai Xu; Bulou, Alain; Wang Qiuping A

2012-01-01

Ranking is a ubiquitous phenomenon in human society. On the web pages of Forbes, one may find all kinds of rankings, such as the world's most powerful people, the world's richest people, the highest-earning tennis players, and so on and so forth. Herewith, we study a specific kind—sports ranking systems in which players' scores and/or prize money are accrued based on their performances in different matches. By investigating 40 data samples which span 12 different sports, we find that the distributions of scores and/or prize money follow universal power laws, with exponents nearly identical for most sports. In order to understand the origin of this universal scaling we focus on the tennis ranking systems. By checking the data we find that, for any pair of players, the probability that the higher-ranked player tops the lower-ranked opponent is proportional to the rank difference between the pair. Such a dependence can be well fitted to a sigmoidal function. By using this feature, we propose a simple toy model which can simulate the competition of players in different matches. The simulations yield results consistent with the empirical findings. Extensive simulation studies indicate that the model is quite robust with respect to the modifications of some parameters. (paper)

O impacto das ideias de Sisto V na cidade : Roma

OpenAIRE

Viegas, Diogo Miguel Estrela Santos Baptista, 1988-

2014-01-01

Dissertação de mestrado integrado em Arquitectura, Universidade Lusíada de Lisboa, 2014 Exame público realizado em 5 de Fevereiro de 2014 Na presente dissertação pretendemos compreender a importância que tiveram as ideias implementadas pelo Papa Sisto V, durante o seu curto pontificado, na cidade de Roma. Assim, numa primeira abordagem, procuraremos perceber a evolução da cidade desde as suas origens até à época do papado de Sisto V, fazendo referência à Cidade Imperial, à Cidade Med...

Analysis of migration trends and functions of areas inhabited by Roma: Example of Međimurje county (Croatia and the settlement of Kuršanec

Directory of Open Access Journals (Sweden)

Kliček Slaven

2016-01-01

Full Text Available Međimurje County stands out as a developed and densely populated county of Central Croatia. Demographic and socio-economic developmental trends of Međimurje indicate the referred-to status: age structure, birth rates, population activity rates and share of jobs are significantly higher than the Croatian average. At the same time, Međimurje is home to one of the largest Croatian Roma communities, ethnically homogeneous and spatially isolated, whose predominantly unfavourable geographical features make the opposite developmental pole of previously described developed areas inhabited by the majority population. Development indicators at county level have omitted concrete living conditions of Roma. They inhabit the rural periphery characterized by social and spatial segregation, unemployment and existence on the margins of society and settlements. This paper provides an analysis of housing, economic and social functions of areas inhabited by Roma, as well as migratory trends and main functional orientation of these areas in Međimurje County. In so, the settlement of Kuršanec will be emphasized as a representative example of areas inhabited by Roma in Međimurje County.

A Novel Method for Control Performance Assessment with Fractional Order Signal Processing and Its Application to Semiconductor Manufacturing

Directory of Open Access Journals (Sweden)

Kai Liu

2018-06-01

Full Text Available The significant task for control performance assessment (CPA is to review and evaluate the performance of the control system. The control system in the semiconductor industry exhibits a complex dynamic behavior, which is hard to analyze. This paper investigates the interesting crossover properties of Hurst exponent estimations and proposes a novel method for feature extraction of the nonlinear multi-input multi-output (MIMO systems. At first, coupled data from real industry are analyzed by multifractal detrended fluctuation analysis (MFDFA and the resultant multifractal spectrum is obtained. Secondly, the crossover points with spline fit in the scale-law curve are located and then employed to segment the entire scale-law curve into several different scaling regions, in which a single Hurst exponent can be estimated. Thirdly, to further ascertain the origin of the multifractality of control signals, the generalized Hurst exponents of the original series are compared with shuffled data. At last, non-Gaussian statistical properties, multifractal properties and Hurst exponents of the process control variables are derived and compared with different sets of tuning parameters. The results have shown that CPA of the MIMO system can be better employed with the help of fractional order signal processing (FOSP.

Freudenthal ranks: GHZ versus W

International Nuclear Information System (INIS)

Borsten, L

2013-01-01

The Hilbert space of three-qubit pure states may be identified with a Freudenthal triple system. Every state has an unique Freudenthal rank ranging from 1 to 4, which is determined by a set of automorphism group covariants. It is shown here that the optimal success rates for winning a three-player non-local game, varying over all local strategies, are strictly ordered by the Freudenthal rank of the shared three-qubit resource. (paper)

Differential invariants for higher-rank tensors. A progress report

International Nuclear Information System (INIS)

Tapial, V.

2004-07-01

We outline the construction of differential invariants for higher-rank tensors. In section 2 we outline the general method for the construction of differential invariants. A first result is that the simplest tensor differential invariant contains derivatives of the same order as the rank of the tensor. In section 3 we review the construction for the first-rank tensors (vectors) and second-rank tensors (metrics). In section 4 we outline the same construction for higher-rank tensors. (author)

Council of Europe. Parliamentary Assembly: Media Provisions in New Texts on (Roma) Migrants and Refugees

NARCIS (Netherlands)

McGonagle, T.

2012-01-01

The Parliamentary Assembly of the Council of Europe (PACE) adopted its Resolution 1889 on the portrayal of migrants and refugees during election campaigns and its Recommendation 2003 (2012) on Roma migrants in Europe on 27 and 28 June 2012 respectively. While formally distinct, the texts display

A comparison of CA125, HE4, risk ovarian malignancy algorithm (ROMA, and risk malignancy index (RMI for the classification of ovarian masses

Directory of Open Access Journals (Sweden)

Cristina Anton

2012-01-01

Full Text Available OBJECTIVE: Differentiation between benign and malignant ovarian neoplasms is essential for creating a system for patient referrals. Therefore, the contributions of the tumor markers CA125 and human epididymis protein 4 (HE4 as well as the risk ovarian malignancy algorithm (ROMA and risk malignancy index (RMI values were considered individually and in combination to evaluate their utility for establishing this type of patient referral system. METHODS: Patients who had been diagnosed with ovarian masses through imaging analyses (n = 128 were assessed for their expression of the tumor markers CA125 and HE4. The ROMA and RMI values were also determined. The sensitivity and specificity of each parameter were calculated using receiver operating characteristic curves according to the area under the curve (AUC for each method. RESULTS: The sensitivities associated with the ability of CA125, HE4, ROMA, or RMI to distinguish between malignant versus benign ovarian masses were 70.4%, 79.6%, 74.1%, and 63%, respectively. Among carcinomas, the sensitivities of CA125, HE4, ROMA (pre-and post-menopausal, and RMI were 93.5%, 87.1%, 80%, 95.2%, and 87.1%, respectively. The most accurate numerical values were obtained with RMI, although the four parameters were shown to be statistically equivalent. CONCLUSION: There were no differences in accuracy between CA125, HE4, ROMA, and RMI for differentiating between types of ovarian masses. RMI had the lowest sensitivity but was the most numerically accurate method. HE4 demonstrated the best overall sensitivity for the evaluation of malignant ovarian tumors and the differential diagnosis of endometriosis. All of the parameters demonstrated increased sensitivity when tumors with low malignancy potential were considered low-risk, which may be used as an acceptable assessment method for referring patients to reference centers.

Occurrence of microsporidia as emerging pathogens in Slovak Roma children and their impact on public health

Czech Academy of Sciences Publication Activity Database

Halanová, M.; Valenčáková, A.; Malčeková, B.; Kváč, Martin; Sak, Bohumil; Květoňová, Dana; Balent, P.; Čisláková, L.

2013-01-01

Roč. 20, č. 4 (2013), s. 695-698 ISSN 1232-1966 Institutional support: RVO:60077344 Keywords : microsporidia * Enterocytozoon bieneusi * Encephalitozoon cuniculi * roma children * zoonotic potential Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 3.060, year: 2012

Ranking accounting, banking and finance journals: A note

OpenAIRE

Halkos, George; Tzeremes, Nickolaos

2012-01-01

This paper by applying Data Envelopment Analysis (DEA) ranks Economics journals in the field of Accounting, Banking and Finance. By using one composite input and one composite output the paper ranks 57 journals. In addition for the first time three different quality ranking reports have been incorporated to the DEA modelling problem in order to classify the journals into four categories (‘A’ to ‘D’). The results reveal that the journals with the highest rankings in the field are Journal of Fi...

Conceptualizing child labour trafficking and exploitation: The case of Roma children in Montenegro

Directory of Open Access Journals (Sweden)

Arhin Antonela

2012-01-01

Full Text Available Trafficking of children for labour exploitation is a profit-oriented criminal activity by which children are recruited, transported, harboured or received for the purpose of labour exploitation irrespective of whether or not force, abduction, fraud or other means were used. This paper examines child labour trafficking in the context of human rights violations and as the worst form of child labour. In an attempt to situate the discourse of alleged labour exploitation and trafficking of Roma children in Montenegro, focusing in particular on instances of child begging, this paper offers an overview of the international legal framework as well as the Government of Montenegro’s policy framework relevant to this issue; an analysis of implicated historical, familial and cultural structures; and focuses on identifying root causes in terms of push-pull factors that are associated with enhancing children’s vulnerability and proneness to exploitation. Along with a set of recommendations, in closing, the paper calls for a more sophisticated analysis of child labour trafficking and, in the case of Roma children, a more nuanced understanding of historical and cultural pretexts against the backdrop of labour trafficking.

Ranking health between countries in international comparisons

DEFF Research Database (Denmark)

Brønnum-Hansen, Henrik

2014-01-01

Cross-national comparisons and ranking of summary measures of population health sometimes give rise to inconsistent and diverging conclusions. In order to minimise confusion, international comparative studies ought to be based on well-harmonised data with common standards of definitions and docum......Cross-national comparisons and ranking of summary measures of population health sometimes give rise to inconsistent and diverging conclusions. In order to minimise confusion, international comparative studies ought to be based on well-harmonised data with common standards of definitions...

L'applicazione dei Sistemi Informativi Geografici per la valutazione dei bisogni di salute della popolazione pediatrica immigrata residente a Roma

Directory of Open Access Journals (Sweden)

A. G. De Belvis

2003-05-01

Full Text Available

Obiettivi: lo studio applica i GIS per l’analisi dei bisogni di salute della popolazione immigrata in età pediatrica regolarmente residente a Roma e per la costruzione di bacini di utenza a livello di Municipio, ASL e Comune rispetto alle corrispondenti strutture di offerta.

Materiali e Metodi: i dati sono stati acquisiti dall’Ufficio Statistica del Comune di Roma (popolazione in età 0-18 anni residente al 31/12/2002 per Municipio, Distretto e ASL. I dati relativi all’offerta dei servizi per l’infanzia delle ASL sono stati reperiti dalle ASL, dal Comune e dalla Caritas di Roma. I dati sono stati successivamente inseriti, verificati ed analizzati attraverso i programmi Excel e Stata7. L’utilizzo delle applicazioni GIS è stato realizzato attraverso il software Arc-View.

Risultati: dei 169.064 immigrati presenti al 31/12/2002, quelli in età pediatrica (29.629 sono variabilmente distribuiti rispetto al totale degli immigrati e alla popolazione pediatrica residente.
Ad esempio, la proporzione immigrati minori/immigrati varia da un minimo del 7,3% in Municipio I, ad un massimo del 20,1% nei Municipi VII e VII (Media: 13.26, I.C.95%: 11.46-15.05.
L’analisi ha permesso di caratterizzare i bisogni socio-sanitari per Municipio, distretto e ASL. Una valutazione quantitativa della relazione bisogno/offerta è stata realizzata georeferenziando la popolazione immigrata in età pediatrica con le corrispondenti strutture di offerta censite.

Conclusioni: l’utilizzo dei GIS in epidemiologia e sanità pubblica si presenta sempre più prezioso, per la capacità di sintetizzare, rappresentare efficacemente i fenomeni, suggerire ipotesi di correlazioni tra i fenomeni e indirizzare le decisioni in sanità.
L’applicazione dei GIS sulla popolazione immigrata in età pediatrica – regolarmente residente a Roma - si è prestata in maniera efficace

Multifractal detrended cross-correlation analysis on gold, crude oil and foreign exchange rate time series

Science.gov (United States)

Pal, Mayukha; Madhusudana Rao, P.; Manimaran, P.

2014-12-01

We apply the recently developed multifractal detrended cross-correlation analysis method to investigate the cross-correlation behavior and fractal nature between two non-stationary time series. We analyze the daily return price of gold, West Texas Intermediate and Brent crude oil, foreign exchange rate data, over a period of 18 years. The cross correlation has been measured from the Hurst scaling exponents and the singularity spectrum quantitatively. From the results, the existence of multifractal cross-correlation between all of these time series is found. We also found that the cross correlation between gold and oil prices possess uncorrelated behavior and the remaining bivariate time series possess persistent behavior. It was observed for five bivariate series that the cross-correlation exponents are less than the calculated average generalized Hurst exponents (GHE) for q0 and for one bivariate series the cross-correlation exponent is greater than GHE for all q values.

Multifractal spectra of scanning electron microscope images of SnO2 thin films prepared by pulsed laser deposition

International Nuclear Information System (INIS)

Chen, Z.W.; Lai, J.K.L.; Shek, C.H.

2005-01-01

The concept of fractal geometry has proved useful in describing structures and processes in experimental systems. In this Letter, the surface topographies of SnO 2 thin films prepared by pulsed laser deposition for various substrate temperatures were measured by scanning electron microscope (SEM). Multifractal spectra f(α) show that the higher the substrate temperature, the wider the spectrum, and the larger the Δf(Δf=f(α min )-f(α max )). It is apparent that the nonuniformity of the height distribution increases with the increasing substrate temperature, and the liquid droplets of SnO 2 thin films are formed on previous thin films. These results show that the SEM images can be characterized by the multifractal spectra

Relative Performance Information, Rank Ordering and Employee Performance: A Research Note

NARCIS (Netherlands)

Kramer, S.; Maas, V.S.; van Rinsum, M.

2016-01-01

We conduct a laboratory experiment to examine whether the provision of detailed relative performance information (i.e., information about the specific performance levels of peers) affects employee performance. We also investigate how – if at all – explicit ranking of performance levels affects how

School Self-Concept of Children in the System of Lower Secondary Education in Slovakia - Comparison of Slovak and Roma Children

Directory of Open Access Journals (Sweden)

Michal Čerešník

2018-02-01

Full Text Available In the paper we compare a school self-concept in Slovak and Roma children in the system of lower secondary education. As a method of diagnostics we used the Student’s Perception of Ability Scale (SPAS, in Slovak Dotazník sebapoňatia školskej úspešnosti detí by Matějček, Vágnerová (1992, who are the authors of the original Czech and Slovak standardisation. We used the innovated form of the scale (Čerešník, 2013. The results of the statistical analysis show significant differences between the compared groups in the monitored indicators of the school self-concept. If we accept that the majority of Roma children come from socially disadvantaged environment then these children belong to children with special educational needs (according to the Act No. 245/2008. Thus, the worse school self-concept in Roma children is not a surprising result. This finding is valid, especially in the relation to possible subdeprivation or deprivation experience based on the deficiency of stimuli leading to saturation of physiological, social and psychological needs.

Ranking adverse drug reactions with crowdsourcing.

Science.gov (United States)

Gottlieb, Assaf; Hoehndorf, Robert; Dumontier, Michel; Altman, Russ B

2015-03-23

There is no publicly available resource that provides the relative severity of adverse drug reactions (ADRs). Such a resource would be useful for several applications, including assessment of the risks and benefits of drugs and improvement of patient-centered care. It could also be used to triage predictions of drug adverse events. The intent of the study was to rank ADRs according to severity. We used Internet-based crowdsourcing to rank ADRs according to severity. We assigned 126,512 pairwise comparisons of ADRs to 2589 Amazon Mechanical Turk workers and used these comparisons to rank order 2929 ADRs. There is good correlation (rho=.53) between the mortality rates associated with ADRs and their rank. Our ranking highlights severe drug-ADR predictions, such as cardiovascular ADRs for raloxifene and celecoxib. It also triages genes associated with severe ADRs such as epidermal growth-factor receptor (EGFR), associated with glioblastoma multiforme, and SCN1A, associated with epilepsy. ADR ranking lays a first stepping stone in personalized drug risk assessment. Ranking of ADRs using crowdsourcing may have useful clinical and financial implications, and should be further investigated in the context of health care decision making.

Ranking Adverse Drug Reactions With Crowdsourcing

KAUST Repository

Gottlieb, Assaf

2015-03-23

Background: There is no publicly available resource that provides the relative severity of adverse drug reactions (ADRs). Such a resource would be useful for several applications, including assessment of the risks and benefits of drugs and improvement of patient-centered care. It could also be used to triage predictions of drug adverse events. Objective: The intent of the study was to rank ADRs according to severity. Methods: We used Internet-based crowdsourcing to rank ADRs according to severity. We assigned 126,512 pairwise comparisons of ADRs to 2589 Amazon Mechanical Turk workers and used these comparisons to rank order 2929 ADRs. Results: There is good correlation (rho=.53) between the mortality rates associated with ADRs and their rank. Our ranking highlights severe drug-ADR predictions, such as cardiovascular ADRs for raloxifene and celecoxib. It also triages genes associated with severe ADRs such as epidermal growth-factor receptor (EGFR), associated with glioblastoma multiforme, and SCN1A, associated with epilepsy. Conclusions: ADR ranking lays a first stepping stone in personalized drug risk assessment. Ranking of ADRs using crowdsourcing may have useful clinical and financial implications, and should be further investigated in the context of health care decision making.

Use of social learning theory in the prevention of obesity with Roma people

Directory of Open Access Journals (Sweden)

Věra Olišarová

2016-12-01

Full Text Available Background: Education is one of the standard components of current nursing care. It is aimed at healthy and diseased and it aims to take responsibility for health. Constantly increasing prevalence of obesity is a global problem. As in the majority population in the Czech Republic and even serious situation of minorities. However, implemented intervention programs and strategies are targeted mainly at the majority population. The concept of social learning theory, however, offers the possibility of integrating previously neglected knowledge as it provides a social context that has a direct impact on the conduct of individuals. Objectives: The aim of this paper is to analyze the problems in the education of the Roma minority and to highlight the possibilities of using the concept of social learning theory in the development of intervention programs aimed at the prevention of overweight and obesity. Methods: This paper is based on data gathered in the implementation of qualitative research, where the research group consists of 25 Roma respondents older than eighteen years of age whose BMI was in the overweight or obese range (ie BMI ≥ 25 kg/m2. Among the respondents were 8 men and 17 women. The paper is also supported by the data obtained in the framework of the grant project aimed, inter alia, to determine the prevalence of these diagnoses among the Roma minority. Results: Culturally conditioned behavior patterns are a significant factor that can influence the effectiveness of implemented interventions. Already during the collection history with these patterns manifest themselves. Among other factors, are body image, social functions of eating, socioeconomic status and related dietary composition. Understanding the relationships between these factors and motivational elements of risk behaviors can go into nursing to bring a new dimension. Conclusions: Ethnicity is often a significant factor that affects the effectiveness of

Characterizing slope morphology using multifractal technique: a study from the western continental margin of India.

Digital Repository Service at National Institute of Oceanography (India)

Chakraborty, B.; Karisiddaiah, S.M.; Menezes, A.A.A.; Haris, K.; Gokul, G.S.; Fernandes, W.A.; Kavitha, G.

margin of India. Geo-Mar Lett 26: 114–119. doi: 10.1007/s00367-006-0022-6 Cheng Q, Agterberg FP (1996) Comparison between two types of multifractal modeling. Math Geol 28 (8): 1001–1015 Dandapath S, Chakraborty B, Maslov N, Karisiddaiah SM...

Side effects of radiotherapy in regime of dynamic dose multifractioning for local larynx cancer forms

International Nuclear Information System (INIS)

Slobina, E.L.

2000-01-01

A regime for dynamic multifractioning of radiotherapy dose used for treating larynx cancer was developed. The method favored reducing the side effects frequency as compared with the conventional fractioning in larynx mucosa from 70% to 46%, in neck skin being irradiated - from 60% to 48%

Symmetries and stochastic symmetry breaking in multifractal geophysics: analysis and simulation with the help of the Lévy-Clifford algebra of cascade generators..

Science.gov (United States)

Schertzer, D. J. M.; Tchiguirinskaia, I.

2016-12-01

Multifractal fields, whose definition is rather independent of their domain dimension, have opened a new approach of geophysics enabling to explore its spatial extension that is of prime importance as underlined by the expression "spatial chaos". However multifractals have been until recently restricted to be scalar valued, i.e. to one-dimensional codomains. This has prevented to deal with the key question of complex component interactions and their non trivial symmetries. We first emphasize that the Lie algebra of stochastic generators of cascade processes enables us to generalize multifractals to arbitrarily large codomains, e.g. flows of vector fields on large dimensional manifolds. In particular, we have recently investigated the neat example of stable Levy generators on Clifford algebra that have a number of seductive properties, e.g. universal statistical and robust algebra properties, both defining the basic symmetries of the corresponding fields (Schertzer and Tchiguirinskaia, 2015). These properties provide a convenient multifractal framework to study both the symmetries of the fields and how they stochastically break the symmetries of the underlying equations due to boundary conditions, large scale rotations and forcings. These developments should help us to answer to challenging questions such as the climatology of (exo-) planets based on first principles (Pierrehumbert, 2013), to fully address the question of the limitations of quasi- geostrophic turbulence (Schertzer et al., 2012) and to explore the peculiar phenomenology of turbulent dynamics of the atmosphere or oceans that is neither two- or three-dimensional. Pierrehumbert, R.T., 2013. Strange news from other stars. Nature Geoscience, 6(2), pp.8183. Schertzer, D. et al., 2012. Quasi-geostrophic turbulence and generalized scale invariance, a theoretical reply. Atmos. Chem. Phys., 12, pp.327336. Schertzer, D. & Tchiguirinskaia, I., 2015. Multifractal vector fields and stochastic Clifford algebra

Ranking periodic ordering models on the basis of minimizing total inventory cost

Directory of Open Access Journals (Sweden)

Mohammadali Keramati

2015-06-01

Full Text Available This paper aims to provide proper policies for inventory under uncertain conditions by comparing different inventory policies. To review the efficiency of these algorithms it is necessary to specify the area in which each of them is applied. Therefore, each of the models has been reviewed under different forms of retailing and they are ranked in terms of their expenses. According to the high values of inventories and their impacts on the costs of the companies, the ranking of various models using the simulation annealing algorithm are presented, which indicates that the proposed model of this paper could perform better than other alternative ones. The results also indicate that the suggested algorithm could save from 4 to 29 percent on costs of inventories.

Co-integration Rank Testing under Conditional Heteroskedasticity

DEFF Research Database (Denmark)

Cavaliere, Guiseppe; Rahbæk, Anders; Taylor, A.M. Robert

null distributions of the rank statistics coincide with those derived by previous authors who assume either i.i.d. or (strict and covariance) stationary martingale difference innovations. We then propose wild bootstrap implementations of the co-integrating rank tests and demonstrate that the associated...... bootstrap rank statistics replicate the first-order asymptotic null distributions of the rank statistics. We show the same is also true of the corresponding rank tests based on the i.i.d. bootstrap of Swensen (2006). The wild bootstrap, however, has the important property that, unlike the i.i.d. bootstrap......, it preserves in the re-sampled data the pattern of heteroskedasticity present in the original shocks. Consistent with this, numerical evidence sug- gests that, relative to tests based on the asymptotic critical values or the i.i.d. bootstrap, the wild bootstrap rank tests perform very well in small samples un...

The Inclusion of Slovak Roma Pupils in Secondary School: Contexts of Language Policy and Planning

Science.gov (United States)

Payne, Mark

2017-01-01

The arrival of large numbers of Slovak Roma to Sheffield over a relatively short period has inserted two new languages (Slovak and Romani) into an already diverse, multilingual school environment. Schools face challenges in welcoming the new migrant children, inducting and integrating them and facilitating access to the English school curriculum.…

A Ranking Method for Evaluating Constructed Responses

Science.gov (United States)

Attali, Yigal

2014-01-01

This article presents a comparative judgment approach for holistically scored constructed response tasks. In this approach, the grader rank orders (rather than rate) the quality of a small set of responses. A prior automated evaluation of responses guides both set formation and scaling of rankings. Sets are formed to have similar prior scores and…

PageRank, HITS and a unified framework for link analysis

Energy Technology Data Exchange (ETDEWEB)

Ding, Chris; He, Xiaofeng; Husbands, Parry; Zha, Hongyuan; Simon, Horst

2001-10-01

Two popular webpage ranking algorithms are HITS and PageRank. HITS emphasizes mutual reinforcement between authority and hub webpages, while PageRank emphasizes hyperlink weight normalization and web surfing based on random walk models. We systematically generalize/combine these concepts into a unified framework. The ranking framework contains a large algorithm space; HITS and PageRank are two extreme ends in this space. We study several normalized ranking algorithms which are intermediate between HITS and PageRank, and obtain closed-form solutions. We show that, to first order approximation, all ranking algorithms in this framework, including PageRank and HITS, lead to same ranking which is highly correlated with ranking by indegree. These results support the notion that in web resource ranking indegree and outdegree are of fundamental importance. Rankings of webgraphs of different sizes and queries are presented to illustrate our analysis.

Degree distributions of the visibility graphs mapped from fractional Brownian motions and multifractal random walks

International Nuclear Information System (INIS)

Ni Xiaohui; Jiang Zhiqiang; Zhou Weixing

2009-01-01

The dynamics of a complex system is usually recorded in the form of time series, which can be studied through its visibility graph from a complex network perspective. We investigate the visibility graphs extracted from fractional Brownian motions and multifractal random walks, and find that the degree distributions exhibit power-law behaviors, in which the power-law exponent α is a linear function of the Hurst index H of the time series. We also find that the degree distribution of the visibility graph is mainly determined by the temporal correlation of the original time series with minor influence from the possible multifractal nature. As an example, we study the visibility graphs constructed from three Chinese stock market indexes and unveil that the degree distributions have power-law tails, where the tail exponents of the visibility graphs and the Hurst indexes of the indexes are close to the α∼H linear relationship.

Multifractal analysis of multiparticle emission data in the framework of visibility graph and sandbox algorithm

Science.gov (United States)

Mali, P.; Manna, S. K.; Mukhopadhyay, A.; Haldar, P. K.; Singh, G.

2018-03-01

Multiparticle emission data in nucleus-nucleus collisions are studied in a graph theoretical approach. The sandbox algorithm used to analyze complex networks is employed to characterize the multifractal properties of the visibility graphs associated with the pseudorapidity distribution of charged particles produced in high-energy heavy-ion collisions. Experimental data on 28Si+Ag/Br interaction at laboratory energy Elab = 14 . 5 A GeV, and 16O+Ag/Br and 32S+Ag/Br interactions both at Elab = 200 A GeV, are used in this analysis. We observe a scale free nature of the degree distributions of the visibility and horizontal visibility graphs associated with the event-wise pseudorapidity distributions. Equivalent event samples simulated by ultra-relativistic quantum molecular dynamics, produce degree distributions that are almost identical to the respective experiment. However, the multifractal variables obtained by using sandbox algorithm for the experiment to some extent differ from the respective simulated results.

Ranking Performance Measures in Multi-Task Agencies

DEFF Research Database (Denmark)

Christensen, Peter Ove; Sabac, Florin; Tian, Joyce

2010-01-01

We derive sufficient conditions for ranking performance evaluation systems in multi-task agency models (using both optimal and linear contracts) in terms of a second-order stochastic dominance (SSD) condition on the likelihood ratios. The SSD condition can be replaced by a variance-covariance mat......We derive sufficient conditions for ranking performance evaluation systems in multi-task agency models (using both optimal and linear contracts) in terms of a second-order stochastic dominance (SSD) condition on the likelihood ratios. The SSD condition can be replaced by a variance...

Fault Diagnosis of Broken Rotor Bars in Squirrel-Cage Induction Motor of Hoister Based on Duffing Oscillator and Multifractal Dimension

Directory of Open Access Journals (Sweden)

Zhike Zhao

2014-07-01

Full Text Available This paper is to propose a novel fault diagnosis method for broken rotor bars in squirrel-cage induction motor of hoister, which is based on duffing oscillator and multifractal dimension. Firstly, based on the analysis of the structure and performance of modified duffing oscillator, the end of transitional slope from chaotic area to large-scale cycle area is selected as the optimal critical threshold of duffing oscillator by bifurcation diagrams and Lyapunov exponent. Secondly, the phase transformation duffing oscillator from chaos to intermittent chaos is sensitive to the signals, whose frequency difference is quite weak from the reference signal. The spectrums of the largest Lyapunov exponents and bifurcation diagrams of the duffing oscillator are utilized to analyze the variance in different parameters of frequency. Finally, this paper is to analyze the characteristics of both single fractal (box-counting dimension and multifractal and make a comparison between them. Multifractal detrended fluctuation analysis is applied to detect extra frequency component of current signal. Experimental results reveal that the method is effective for early detection of broken rotor bars in squirrel-cage induction motor of hoister.

Rank Dynamics

Science.gov (United States)

Gershenson, Carlos

Studies of rank distributions have been popular for decades, especially since the work of Zipf. For example, if we rank words of a given language by use frequency (most used word in English is 'the', rank 1; second most common word is 'of', rank 2), the distribution can be approximated roughly with a power law. The same applies for cities (most populated city in a country ranks first), earthquakes, metabolism, the Internet, and dozens of other phenomena. We recently proposed ``rank diversity'' to measure how ranks change in time, using the Google Books Ngram dataset. Studying six languages between 1800 and 2009, we found that the rank diversity curves of languages are universal, adjusted with a sigmoid on log-normal scale. We are studying several other datasets (sports, economies, social systems, urban systems, earthquakes, artificial life). Rank diversity seems to be universal, independently of the shape of the rank distribution. I will present our work in progress towards a general description of the features of rank change in time, along with simple models which reproduce it

Extraction of Coal and Gangue Geometric Features with Multifractal Detrending Fluctuation Analysis

Directory of Open Access Journals (Sweden)

Kai Liu

2018-03-01

Full Text Available The separation of coal and gangue is an important process of the coal preparation technology. The conventional way of manual selection and separation of gangue from the raw coal can be replaced by computer vision technology. In the literature, research on image recognition and classification of coal and gangue is mainly based on the grayscale and texture features of the coal and gangue. However, there are few studies on characteristics of coal and gangue from the perspective of their outline differences. Therefore, the multifractal detrended fluctuation analysis (MFDFA method is introduced in this paper to extract the geometric features of coal and gangue. Firstly, the outline curves of coal and gangue in polar coordinates are detected and achieved along the centroid, thereby the multifractal characteristics of the series are analyzed and compared. Subsequently, the modified local singular spectrum widths Δ h of the outline curve series are extracted as the characteristic variables of the coal and gangue for pattern recognition. Finally, the extracted geometric features by MFDFA combined with the grayscale and texture features of the images are compared with other methods, indicating that the recognition rate of coal gangue images can be increased by introducing the geometric features.

Youth subcultures and problem behaviours in Slovakia : Hip-Hop, Techno-scene, Metal, Punk, Skinheads and Roma

NARCIS (Netherlands)

Bobakova, Daniela

2013-01-01

Jongeren die deel uitmaken van jeugdsubculturen als hip-hop, techno-scene, metal, punk en skinheads, gebruiken vaker drugs, zijn vaker dronken, spijbelen vaker en beginnen eerder aan seks. Roma-jongeren zijn minder vaak dronken. Dat concludeert Daniela Bobáková op basis van een onderzoek onder deze

Fractal and multifractal characteristics of swift heavy ion induced self-affine nanostructured BaF{sub 2} thin film surfaces

Energy Technology Data Exchange (ETDEWEB)

Yadav, R. P.; Mittal, A. K. [Department of Physics, University of Allahabad, Allahabad 211002 (India); Kumar, Manvendra, E-mail: kmanav@gmail.com; Pandey, A. C. [Nanotechnology Application Centre, University of Allahabad, Allahabad 211002 (India)

2015-08-15

Fractal and multifractal characteristics of self-affine surfaces of BaF{sub 2} thin films, deposited on crystalline Si 〈1 1 1〉 substrate at room temperature, were studied. Self-affine surfaces were prepared by irradiation of 120 MeV Ag{sup 9+} ions which modified the surface morphology at nanometer scale. The surface morphology of virgin thin film and those irradiated with different ion fluences are characterized by atomic force microscopy technique. The surface roughness (interface width) shows monotonic decrease with ion fluences, while the other parameters, such as lateral correlation length, roughness exponent, and fractal dimension, did not show either monotonic decrease or increase in nature. The self-affine nature of the films is further confirmed by autocorrelation function. The power spectral density of thin films surfaces exhibits inverse power law variation with spatial frequency, suggesting the existence of fractal component in surface morphology. The multifractal detrended fluctuation analysis based on the partition function approach is also performed on virgin and irradiated thin films. It is found that the partition function exhibits the power law behavior with the segment size. Moreover, it is also seen that the scaling exponents vary nonlinearly with the moment, thereby exhibiting the multifractal nature.

Economic strategies and migratory trajectories of Vlax Roma from Eastern Slovakia to Leicester, UK

Directory of Open Access Journals (Sweden)

Markéta Hajská

2017-12-01

Full Text Available The article is based on long term field research and focuses on a community of family-related Vlax Roma from the Prešov, Sabinov and Košice regions who created a large community in Leicester, UK. The massive wave of labour migration to UK started in 2004, in the year of Slovakia’s accession to the European Union. The migration to Great Britain has been based on family networks and represents an example of chain migration based on the reciprocal help of family networks. Besides their own relatives other different non-related Roma intermediaries had an important influence on their arrival to Britain. The article focuses on the changing economic strategies of new migrants from the group in focus after their replacement to UK. In the years following Slovak accession to the EU, the prospective Romani migrants explored many illegal paths to arrive to Britain in their struggle for a better life. Approximately after a decade since their arrival, we can find this community as fully integrated into the local British working class, spending their time between my work and my house.

Multifractal characteristics of optical turbulence measured through a single beam holographic process

OpenAIRE

Perez, Dario G.; Barille, Regis; Morille, Yohann; Zielinska, Sonia; Ortyl, Ewelina

2014-01-01

We have previously shown that azopolymer thin films exposed to coherent light that has travelled through a turbulent medium produces a surface relief grating containing information about the intensity of the turbulence; for instance, a relation between the refractive index structure constant C2 as a function of the surface parameters was obtained. In this work, we show that these films capture much more information about the turbulence dynamics. Multifractal detrended fluctuation and fractal ...

Personality traits in old age: measurement and rank-order stability and some mean-level change.

Science.gov (United States)

Mõttus, René; Johnson, Wendy; Deary, Ian J

2012-03-01

Lothian Birth Cohorts, 1936 and 1921 were used to study the longitudinal comparability of Five-Factor Model (McCrae & John, 1992) personality traits from ages 69 to 72 years and from ages 81 to 87 years, and cross-cohort comparability between ages 69 and 81 years. Personality was measured using the 50-item International Personality Item Pool (Goldberg, 1999). Satisfactory measurement invariance was established across time and cohorts. High rank-order stability was observed in both cohorts. Almost no mean-level change was observed in the younger cohort, whereas Extraversion, Agreeableness, Conscientiousness, and Intellect declined significantly in the older cohort. The older cohort scored higher on Agreeableness and Conscientiousness. In these cohorts, individual differences in personality traits continued to be stable even in very old age, mean-level changes accelerated.

Log wavelet leaders cumulant based multifractal analysis of EVI fMRI time series: evidence of scaling in ongoing and evoked brain activity

Energy Technology Data Exchange (ETDEWEB)

Ciuciu, P.; Rabrait, C. [CEA, Neuro Spin, Gif Sur Yvette (France); Abry, P.; Wendt, H. [Ecole Normale Super Lyon, Phys Lab, CNRS, UMR 5672, Lyon (France)

2008-07-01

Classical within-subject analysis in functional magnetic resonance imaging (fMRI) relies on a detection step to localize which parts of the brain are activated by a given stimulus type. This is usually achieved using model-based approaches. Here, we propose an alternative exploratory analysis. The originality of this contribution is twofold. First, we propose a synthetic, consistent, and comparative overview of the various stochastic processes and estimation procedures used to model and analyze scale invariance. Notably, it is explained how multifractal models are more versatile to adjust the scaling properties of fMRI data but require more elaborated analysis procedures. Second, we bring evidence of the existence of actual scaling in fMRI time series that are clearly disentangled from putative superimposed non-stationarities. By nature, scaling analysis requires the use of long enough signals with high frequency sampling rate. To this end, we make use of a localized 3-D echo volume imaging (EVI) technique, which has recently emerged in fMRI because it allows very fast acquisitions of successive brain volumes. High temporal resolution EVI fMRI data have been acquired both in resting state and during a slow event-related visual paradigm. A voxel-based systematic multifractal analysis has been performed over both kinds of data. Combining multifractal attribute estimates together with paired statistical tests, we observe significant scaling parameter changes between ongoing and evoked brain activity, which clearly validate an increase in long memory and suggest a global multi-fractality decrease effect under activation. (authors)

Removing divergences in the negative moments of the multi-fractal parition function with the wavelet transformation

NARCIS (Netherlands)

Z.R. Struzik

1998-01-01

textabstractWe present a promising technique which is capable of accessing the divergence free component of the partition function for the negative moments of the multi-fractal analysis of data using the wavelet transformation. It is based on implicitly bounding the local logarithmic slope of the

A Rank-Constrained Matrix Representation for Hypergraph-Based Subspace Clustering

Directory of Open Access Journals (Sweden)

Yubao Sun

2015-01-01

Full Text Available This paper presents a novel, rank-constrained matrix representation combined with hypergraph spectral analysis to enable the recovery of the original subspace structures of corrupted data. Real-world data are frequently corrupted with both sparse error and noise. Our matrix decomposition model separates the low-rank, sparse error, and noise components from the data in order to enhance robustness to the corruption. In order to obtain the desired rank representation of the data within a dictionary, our model directly utilizes rank constraints by restricting the upper bound of the rank range. An alternative projection algorithm is proposed to estimate the low-rank representation and separate the sparse error from the data matrix. To further capture the complex relationship between data distributed in multiple subspaces, we use hypergraph to represent the data by encapsulating multiple related samples into one hyperedge. The final clustering result is obtained by spectral decomposition of the hypergraph Laplacian matrix. Validation experiments on the Extended Yale Face Database B, AR, and Hopkins 155 datasets show that the proposed method is a promising tool for subspace clustering.

Decomposition of the Google PageRank and Optimal Linking Strategy

NARCIS (Netherlands)

Avrachenkov, Konstatin; Litvak, Nelli

We provide the analysis of the Google PageRank from the perspective of the Markov Chain Theory. First we study the Google PageRank for a Web that can be decomposed into several connected components which do not have any links to each other. We show that in order to determine the Google PageRank for

The mediating effect of discrimination, social support and hopelessness on self-rated health of Roma adolescents in Slovakia

NARCIS (Netherlands)

Kolarcik, Peter; Geckova, Andrea Madarasova; Reijneveld, Sijmen A.; Van Dijk, Jitse P.

2015-01-01

Background: According to the EU-MIDIS report on discrimination, Roma are the most discriminated against group in Europe. Research suggests that experiencing discrimination may itself be detrimental to health. The aim of this paper is to investigate whether discrimination, hopelessness and social

Multifractal fluctuations in joint angles during infant spontaneous kicking reveal multiplicativity-driven coordination

International Nuclear Information System (INIS)

Stephen, Damian G.; Hsu, Wen-Hao; Young, Diana; Saltzman, Elliot L.; Holt, Kenneth G.; Newman, Dava J.; Weinberg, Marc; Wood, Robert J.; Nagpal, Radhika; Goldfield, Eugene C.

2012-01-01

Previous research has considered infant spontaneous kicking as a form of exploration. According to this view, spontaneous kicking provides information about motor degrees of freedom and may shape multijoint coordinations for more complex movement patterns such as gait. Recent work has demonstrated that multifractal, multiplicative fluctuations in exploratory movements index energy flows underlying perceptual-motor information. If infant spontaneous kicking is exploratory and occasions an upstream flow of information from the motor periphery, we expected not only that multiplicativity of fluctuations at the hip should promote multiplicativity of fluctuations at more distal joints (i.e., reflecting downstream effects of neural control) but also that multiplicativity at more distal joints should promote multiplicativity at the hip. Multifractal analysis demonstrated that infant spontaneous kicking in four typically developing infants for evidence of multiplicative fluctuations in multiple joint angles along the leg (i.e., hip, knee, and ankle) exhibited multiplicativity. Vector autoregressive modeling demonstrated that only one leg exhibited downstream effects but that both legs exhibited upstream effects. These results confirm the exploratory aspect of infant spontaneous kicking and suggest chaotic dynamics in motor coordination. They also resonate with existing models of chaos-controlled robotics and noise-based interventions for rehabilitating motor coordination in atypically developing patients.

Scalable Faceted Ranking in Tagging Systems

Science.gov (United States)

Orlicki, José I.; Alvarez-Hamelin, J. Ignacio; Fierens, Pablo I.

Nowadays, web collaborative tagging systems which allow users to upload, comment on and recommend contents, are growing. Such systems can be represented as graphs where nodes correspond to users and tagged-links to recommendations. In this paper we analyze the problem of computing a ranking of users with respect to a facet described as a set of tags. A straightforward solution is to compute a PageRank-like algorithm on a facet-related graph, but it is not feasible for online computation. We propose an alternative: (i) a ranking for each tag is computed offline on the basis of tag-related subgraphs; (ii) a faceted order is generated online by merging rankings corresponding to all the tags in the facet. Based on the graph analysis of YouTube and Flickr, we show that step (i) is scalable. We also present efficient algorithms for step (ii), which are evaluated by comparing their results with two gold standards.

Cascade-Driven Series with Narrower Multifractal Spectra Than Their Surrogates: Standard Deviation of Multipliers Changes Interactions across Scales

Directory of Open Access Journals (Sweden)

Jun Taek Lee

2017-01-01

Full Text Available Multifractal (or singularity spectra widths w allow diagnosing cascade structure through comparing original series’ widths wOrig to surrogate series’ widths wSurr. However, interpretations of 0Multifractal detrended fluctuation analysis (MF-DFA and Chhabra and Jensen’s method provided two estimates of wOrig for 200 simulated series at each value 0.1≤σ≤1.1 incrementing by 0.05. Increasing σ draws wOrig away from wSurr

Environmental Equity through Negotiation: A Case Study on Urban Landfills and the Roma Community

Science.gov (United States)

Petrescu-Mag, Ruxandra Mălina; Petrescu, Dacinia Crina; Oroian, Ioan Gheorghe; Safirescu, Ovidiu Călin; Bican-Brișan, Nicoleta

2016-01-01

The paper discusses the necessity to bring environmental equity within the Pata Rât Roma community in Northwest Romania, relying on the answers to three questions: “Does environmental equity exist in Pata Rât?”, “How can it be attained?”, and “To what extent can it be brought to the targeted people?” It was shown how a trio of factors tailors the destiny of Roma inhabitants: being a minority, their ethnicity, and the fact they are living on and off what society rejects and dumps—a landfill. The framing of the environmental equity concerns within a vision considering negotiation as the most adequate means to attain it is a novel approach. Further on, the results of the study can fuel win-win solutions in environmental equity. The information abstracted from a set of indicators, assessed through an evaluation matrix, represents a beneficial platform for future bottom-up decisions concerning landfill residents. Three action options were analyzed: on-site living opportunities—that resulted to be preferred, off-site living opportunities, and “Do nothing”. The analysis provides qualitative evidence that the evaluation of environmental equity is largely subjective, because of its complexity and specificity related to geographical, historical, cultural characteristics, and political interests. PMID:27314371

Environmental Equity through Negotiation: A Case Study on Urban Landfills and the Roma Community.

Science.gov (United States)

Petrescu-Mag, Ruxandra Mălina; Petrescu, Dacinia Crina; Oroian, Ioan Gheorghe; Safirescu, Ovidiu Călin; Bican-Brișan, Nicoleta

2016-06-14

The paper discusses the necessity to bring environmental equity within the Pata Rât Roma community in Northwest Romania, relying on the answers to three questions: "Does environmental equity exist in Pata Rât?", "How can it be attained?", and "To what extent can it be brought to the targeted people?" It was shown how a trio of factors tailors the destiny of Roma inhabitants: being a minority, their ethnicity, and the fact they are living on and off what society rejects and dumps-a landfill. The framing of the environmental equity concerns within a vision considering negotiation as the most adequate means to attain it is a novel approach. Further on, the results of the study can fuel win-win solutions in environmental equity. The information abstracted from a set of indicators, assessed through an evaluation matrix, represents a beneficial platform for future bottom-up decisions concerning landfill residents. Three action options were analyzed: on-site living opportunities-that resulted to be preferred, off-site living opportunities, and "Do nothing". The analysis provides qualitative evidence that the evaluation of environmental equity is largely subjective, because of its complexity and specificity related to geographical, historical, cultural characteristics, and political interests.

I luoghi del desiderio nella narrativa di Federigo Tozzi: Siena e Roma / The places of desire in the narrative of Federigo Tozzi: Siena and Roma

Directory of Open Access Journals (Sweden)

Carlo Serafini

2017-12-01

Full Text Available I luoghi del desiderio nella narrativa di Federigo Tozzi: Siena e Roma   In Tozzi le descrizioni paesaggistiche sono invito a considerare i luoghi visti come strumenti di una realtà esterna cui rimandano, una realtà capace di svelare il significato arcano delle cose, la risposta al perché della sofferenza umana, problema fondamentale per lo scrittore. L’immergersi nella natura stimola il desiderio di tranquillità, di pace, di riposo, insieme alla consapevolezza dell’impossibilità di realizzarlo in questa vita. Ecco allora che la natura si pone come il veicolo che porta ad una dimensione esterna a questa vita, la stessa che spesso nello scrittore rappresenta il desiderio di infinito di certe descrizioni. Nel saggio vengono passate in rassegna alcune descrizioni emblematiche della campagna senese e di Siena stessa, e messe poi in rapporto con le suggestioni che lo scrittore ebbe nel confronto con Roma e la campagna romana.   In Tozzi, landscaping descriptions are an invitation to consider the places seen as instruments of an external reality to which they refer, a reality able to reveal the arcane meaning of things, the answer to the cause of human suffering, a fundamental problem for the writer. Diving into the nature stimulates the desire for tranquility, peace, rest, along with the awareness of the impossibility of realizing it in this life. Here, then, nature is placed as the vehicle that leads to an external dimension respect to this life, the same that often in the writer represents the desire for infinity of some descriptions. In the essay, some of the emblematic descriptions ofSienacity and countryside are examined and then compared to the awesomeness the writer experienced in comparison withRomeand the Roman countryside.

Experiences of well-being among Sami and Roma women in a Swedish context

OpenAIRE

Aléx, Lena; Lehti, Arja

2013-01-01

Artikkel basert på intervju med eldre samiske kvinner og middeladrende Rom kvinner i Sverige. Our aim was to explore the experiences of well-being and lack of well-being among middle-aged and older women belonging to two national minority groups in Sweden. Interviews from nine older Sami women and four middle-aged Roma women were analyzed using grounded theory with the following categories identified: contributing to well-being (with the subcategories belonging to a healthy family, being s...

Multifractal Detrended Fluctuation Analysis of Self-Potential Field Prior to the M 6.5, October 24, 1993 Earthquake in MÉXICO

Science.gov (United States)

Cervantes, F.; González-Trejo, J. I.; Real-Ramírez, C. A.; Hoyos-Reyes, L. F.; Area de Sistemas Computacionales

2013-05-01

In the current literature on seismo electromagnetic, it has been reported many earthquakes which present electromagnetic anomalies as probable precursors of their occurrences. Although this methodology remains yet under discussion, is relevant to study many particular cases. In this work, we report a multifractal detrended fluctuation analysis (MFDFA) of electroseismic signals recorded in the Acapulco station during 1993. In October 24, 1993, occurred and earthquake (EQ) with M 6.5, with epicenter at (16.54 N, 98.98 W), 100Km away from the mentioned station. The multifractal spectrum identifies the deviations in fractal structure within time periods with large and small fluctuations. We discuss the dynamical meaning of this analysis and its possible relation with the mentioned EQ.

PageRank and rank-reversal dependence on the damping factor

Science.gov (United States)

Son, S.-W.; Christensen, C.; Grassberger, P.; Paczuski, M.

2012-12-01

PageRank (PR) is an algorithm originally developed by Google to evaluate the importance of web pages. Considering how deeply rooted Google's PR algorithm is to gathering relevant information or to the success of modern businesses, the question of rank stability and choice of the damping factor (a parameter in the algorithm) is clearly important. We investigate PR as a function of the damping factor d on a network obtained from a domain of the World Wide Web, finding that rank reversal happens frequently over a broad range of PR (and of d). We use three different correlation measures, Pearson, Spearman, and Kendall, to study rank reversal as d changes, and we show that the correlation of PR vectors drops rapidly as d changes from its frequently cited value, d0=0.85. Rank reversal is also observed by measuring the Spearman and Kendall rank correlation, which evaluate relative ranks rather than absolute PR. Rank reversal happens not only in directed networks containing rank sinks but also in a single strongly connected component, which by definition does not contain any sinks. We relate rank reversals to rank pockets and bottlenecks in the directed network structure. For the network studied, the relative rank is more stable by our measures around d=0.65 than at d=d0.

PageRank and rank-reversal dependence on the damping factor.

Science.gov (United States)

Son, S-W; Christensen, C; Grassberger, P; Paczuski, M

2012-12-01

PageRank (PR) is an algorithm originally developed by Google to evaluate the importance of web pages. Considering how deeply rooted Google's PR algorithm is to gathering relevant information or to the success of modern businesses, the question of rank stability and choice of the damping factor (a parameter in the algorithm) is clearly important. We investigate PR as a function of the damping factor d on a network obtained from a domain of the World Wide Web, finding that rank reversal happens frequently over a broad range of PR (and of d). We use three different correlation measures, Pearson, Spearman, and Kendall, to study rank reversal as d changes, and we show that the correlation of PR vectors drops rapidly as d changes from its frequently cited value, d_{0}=0.85. Rank reversal is also observed by measuring the Spearman and Kendall rank correlation, which evaluate relative ranks rather than absolute PR. Rank reversal happens not only in directed networks containing rank sinks but also in a single strongly connected component, which by definition does not contain any sinks. We relate rank reversals to rank pockets and bottlenecks in the directed network structure. For the network studied, the relative rank is more stable by our measures around d=0.65 than at d=d_{0}.

Kriging accelerated by orders of magnitude: combining low-rank with FFT techniques

KAUST Repository