On the singular homology of one class of simply-connected cell-like spaces

In our earlier papers we constructed examples of 2-dimensional nonaspherical simply-connected cell-like Peano continua, called {\sl Snake space}. In the sequel we introduced the functor $SC(-,-)$ defined on the category of all spaces with base points and continuous mappings. For the circle $S^1$, the space $SC(S^1, \ast)$ is a Snake space. In the present paper we study the higher-dimensional homology and homotopy properties of the spaces $SC(Z, \ast)$ for any path-connected compact spaces $Z$

The shadow of past rivalry: limits of post-1999 dynamism in Greco-Turkish relations

This essay will enquire whether Turkey and Greece could remove their enduring controversies through confidence building measures, mediation and inter-governmental dialogues which were introduced in the post-1999 détente period. The paper will specifically focus on the recent nature of understanding between the two countries and will endeavour to answer the question of whether there is a divergence in the nature of recent cooperative arrangements from those which were concluded in the former periods of détente and each of which were disrupted by succeeding periods of either armed conflict or cold war. The paper contends that the recent nature of Greek-Turkish relations is not problem-free. Yet, the new cooperative environment facilitated by confidence building measures and growing mutual understanding could help resolve the disputes and dispel reservations in the Aegean and Cyprus which have been very central to national security considerations of both Turkey and Greece. From a security perspective, continuation of previous policies towards one another is counterproductive in the post-1999 period. Improvement of a bilateral dialogue under the EU umbrella is detrimental for the defence considerations of both Turkey and Greece

On-line tracing of XACML-based policy coverage criteria

Currently, eXtensible Access Control Markup Language (XACML) has becoming the standard for implementing access control policies and consequently more attention is dedicated to testing the correctness of XACML policies. In particular, coverage measures can be adopted for assessing test strategy effectiveness in exercising the policy elements. This study introduces a set of XACML coverage criteria and describes the access control infrastructure, based on a monitor engine, enabling the coverage criterion selection and the on-line tracing of the testing activity. Examples of infrastructure usage and of assessment of different test strategies are provided.Comment: 9 pages, IET Software, available online http://digital-library.theiet.org/content/journals/10.1049/iet-sen.2017.035

Gaussian Behavior of Quadratic Irrationals

We study the probabilistic behaviour of the continued fraction expansion of a quadratic irrational number, when weighted by some "additive" cost. We prove asymptotic Gaussian limit laws, with an optimal speed of convergence. We deal with the underlying dynamical system associated with the Gauss map, and its weighted periodic trajectories. We work with analytic combinatorics methods, and mainly with bivariate Dirichlet generating functions; we use various tools, from number theory (the Landau Theorem), from probability (the Quasi-Powers Theorem), or from dynamical systems: our main object of study is the (weighted) transfer operator, that we relate with the generating functions of interest. The present paper exhibits a strong parallelism with the methods which have been previously introduced by Baladi and Vall\'ee in the study of rational trajectories. However, the present study is more involved and uses a deeper functional analysis framework.Comment: 39 pages In this second version, we have added an annex that provides a detailed study of the trace of the weighted transfer operator. We have also corrected an error that appeared in the computation of the norm of the operator when acting in the Banach space of analytic functions defined in the paper. Also, we give a simpler proof for Theorem

On the second homotopy group of SC(Z)SC(Z)

In our earlier paper (K. Eda, U. Karimov, and D. Repov\v{s}, \emph{A construction of simply connected noncontractible cell-like two-dimensional Peano continua}, Fund. Math. \textbf{195} (2007), 193--203) we introduced a cone-like space $SC(Z)$. In the present note we establish some new algebraic properties of $SC(Z)$

Match of the Day: The search for a suitable spouse

The institutions of family and marriage may seem beyond the remit of economics, involving complexities which the discipline could only ever assume away. There is, however, a significant body of research, which applies the adaptable economists’ toolbox to these areas of life, often yielding a significant degree of insight. Gary Becker’s seminal Treatise on the Family, one of the first studies to subject decisions about sex, marriage, childbearing and childrearing to economic analysis, employed concepts such as the maximisation of family, or household, utility functions to explain family collective choice, with later authors using game theoretic models to offer a different perspective on the intra-household distribution of goods. However, the well-documented phenomenon of urban areas having higher divorce rates than rural regions is not addressed by existing family economics literature, despite the importance of such trends to social policy planners. We develop a new model that provides a theoretical basis for the difference in rural and urban divorce rates, drawing on insights from labour economics and social psychology that have not previously been applied to family economics.Economics; Family; Divorce