First-Fit colorings of graphs with no cycles of a prescribed even length

The First-Fit (or Grundy) chromatic number of a graph G denoted by \(\chi _{{_\mathsf{FF}}}(G)\), is the maximum number of colors used by the First-Fit (greedy) coloring algorithm when applied to G. In this paper we first show that any graph G contains a bipartite subgraph of Grundy number \(\lfloor \chi _{{_\mathsf{FF}}}(G) /2 \rfloor +1\). Using this result we prove that for every \(t\ge 2\) there exists a real number \(c>0\) such that in every graph G on n vertices and without cycles of length 2t, any First-Fit coloring of G uses at most \(cn^{1/t}\) colors. It is noted that for \(t=2\) this bound is the best possible. A compactness conjecture is also proposed concerning the First-Fit chromatic number involving the even girth of graphs.     

A Fragmented Discourse of Religious Leadership in France: Muslim Youth between Citizenship and Radicalization

Abstract

At a time when public debates about radicalization of Muslim youth in the West are taking center stage and when questions about “home-grown” security threats are increasing in the wake of a number of terrorist attacks in many émigré societies, this article provides fresh empirical insights from the perspective of religious leadership. It outlines a picture of a highly diverse Muslim religious landscape where competing religious discourses are struggling to attract and support Muslim youth facing social dislocation and identity crises within increasingly contested social milieus. The article argues that a typology of religious leadership is clearly emerging where a spectrum of faith-based orientations and religious practice emphasize, to different degrees, notions of attachment to universal ethics and individual agency. The fact that conservative, sometimes radical, interpretations of such contestations represent a minority of voices is heartening even though the actual damage by such minority is often disproportionate to its actual size within the so-called silent majority. The empirical insights provided by the religious leaders interviewed for this study offer hope that the future of Western Muslims is more positive than we are led to think, if the possibility of combining devout faith with local political engagement becomes a real and sustainable conduit towards social inclusion and intercultural understanding and if necessary support and understanding are extended by the host communities.     

The Internal Validity of the Trade-Off Method of Conjoint Analysis

The discovery of consumers' preferences for multiattribute products/services has recently become possible with the development of conjoint measurement techniques. Conjoint analysis uses an individual's preference ranking or rating of some deliberately manipulated constructs of a concept to determine his/her numerically valued preferences for levels of those attributes that comprise the concept. Generally speaking, there are two methods of data collection for conjoint analysis: the full profile and the trade-off methods. This paper calls into question the internal validity of the preferences obtained via the trade-off method. An empirical analysis, which is based on the subjects' preferences for selecting a hospital, clearly shows that the estimates derived from the trade-off method may not reflect consumers' true preferences.     

A new generalized odd log-logistic family of distributions

We introduce and study general mathematical properties of a new generator of continuous distributions with three extra parameters called the new generalized odd log-logistic family of distributions. The proposed family contains several important classes discussed in the literature as submodels such as the proportional reversed hazard rate and odd log-logistic classes. Its density function can be expressed as a mixture of exponentiated densities based on the same baseline distribution. Some of its mathematical properties including ordinary moments, quantile and generating functions, entropy measures, and order statistics, which hold for any baseline model, are presented. We also present certain characterization of the proposed distribution and derive a power series for the quantile function. We discuss the method of maximum likelihood to estimate the model parameters. We study the behavior of the maximum likelihood estimator via simulation. The importance of the new family is illustrated by means of two real data sets. These applications indicate that the new family can provide better fits than other well-known classes of distributions. The beauty and importance of the new family lies in its ability to model real data.     

Inference on the asymptotic behavior of covariance operator of first-order periodically correlated autoregressive Hilbertian processes

This paper is devoted to a study on the structure of tensorial products of periodically correlated autoregressive (PCAR) processes with values in separable Hilbert spaces. It will be demonstrated that the resulting processes are PCAR with values in the space of Hilbert–Schmidt operators. These processes are applied while studying the convergence rate, limiting behavior and asymptotic distribution of the empirical estimators of the covariance operators of PCAR processes.     

Marriage and Family Formation of the Second‐Generation Afghans in Iran: Insights from a Qualitative Study

In 2006, around 1.2 million documented Afghans remained in Iran, of whom half were second generation. This paper is based on the results of a qualitative study conducted in three settings: Tehran, Mashhad and Isfahan, and draws on data collected via 80 in‐depth interviews and six focus group discussions with second generation Afghans in Iran. The aim of the paper is to explore the adaptation of second‐generation Afghans in Iran, particularly in relation to marriage and family formation. The results show that educational achievements and occupational skills of the second‐generation Afghans in Iran facilitated their adaptation to the host society, and inspired different marriage and family behaviors and aspirations in comparison with the first generation.     

Integer programming approach to static monopolies in graphs

A subset M of vertices of a graph is called a static monopoly, if any vertex v outside M has at least \(\lceil \tfrac{1 }{2}\deg (v)\rceil \) neighbors in M. The minimum static monopoly problem has been extensively studied in graph theoretical context. We study this problem from an integer programming point of view for the first time and give a linear formulation for it. We study the facial structure of the corresponding polytope, classify facet defining inequalities of the integer programming formulation and introduce some families of valid inequalities. We show that in the presence of a vertex cut or an edge cut in the graph, the problem can be solved more efficiently by adding some strong valid inequalities. An algorithm is given that solves the minimum monopoly problem in trees and cactus graphs in linear time. We test our methods by performing several experiments on randomly generated graphs. A software package is introduced that solves the minimum monopoly problem using open source integer linear programming solvers.     

The Evolution of the Temporary Protection Visa Regime in Australia

While the Temporary Protection Visa (TPV) regime was formally introduced in October 1999 by the Howard Government, the concept of temporary protection was not totally alien to the Australian humanitarian landscape. Earlier examples reflected a standard use of temporary protection as a complementary or interim protection mechanism, offering short‐term group‐based protection where individual assessment under the 1951 Convention was both impractical and untimely. This paper focuses on the wider and more controversial changes in the use of temporary protection mechanisms that were to follow with the introduction of the TPV in 1999, which offered substitute protection for individually assessed Convention refugees who had arrived onshore without valid travel documents. It examines the history and evolution of the TPV policy regime from 1999 to the announcement of its abolition in 2008, arguing that the introduction and subsequent development of the policy may be understood as a product of a conservative, exclusionist political climate in Australia, following the unprecedented impact of the populist One Nation party in 1998, and later, the impact of September 11th. It also examines later amendments to the regime as a response to growing domestic disquiet about the impacts of the policy, and the abolition of the TPV policy under a new Australian government elected in late 2007.     

Discrimination Measures for Fractional Integrated Models Based on Wavelets

Discrimination measures have been well developed for stationary time series. However in a large number of phenomena, long-term dependencies are involved. In this article, we are dealing with discrimination of fractional integrated models. Kullback–Leibler and Chernoff's discrimination measures are approximated, using the discrete wavelet transform (DWT) for discrimination of these time series classes. The simulation study indicates low misclassification rate, related to the approximations of Kullback–Leibler and Chernoff discrimination measures. Application to problem of classifying seismic data showed that our procedure performs as well as other procedures.