Parametric Modelling of Multivariate Count Data Using Probabilistic Graphical Models

Multivariate count data are defined as the number of items of different categories issued from sampling within a population, which individuals are grouped into categories. The analysis of multivariate count data is a recurrent and crucial issue in numerous modelling problems, particularly in the fields of biology and ecology (where the data can represent, for example, children counts associated with multitype branching processes), sociology and econometrics. We focus on I) Identifying categories that appear simultaneously, or on the contrary that are mutually exclusive. This is achieved by identifying conditional independence relationships between the variables; II)Building parsimonious parametric models consistent with these relationships; III) Characterising and testing the effects of covariates on the joint distribution of the counts. To achieve these goals, we propose an approach based on graphical probabilistic models, and more specifically partially directed acyclic graphs

Adequate Capital and Stress Testing for Operational Risks

We describe how the notion of sequential correlations naturally leads to the quantification of operational risk. Our main point is that functional dependencies between mutually supportive processes give rise to non-trivial temporal correlations, which can lead to the occurrence of collective risk events in the form of bursts and avalanches of process failures, and crashes of process networks. We show how the adequate capital for operational risk can be calculated via a stochastic dynamics defined on a topological network of interacting processes. One of the main virtues of the present model is the suitability for capital allocation and stress testing of operational risks

Bill Would Encourage Effective Dispute Resolution

Many of the processes involved in traditional local land use review procedures involve two or more adversarial parties arguing their position with little to no consideration for the other party’s interest, and no regard for mutually beneficial outcome. This article describes a proposed New York law that would promote the use of mediation to supplement the traditional process. The article discusses studies geared towards testing the effectiveness of mediation, gives a review of out of state mediation legislation, as discusses corresponding court decisions. Finally, the article concludes with a review of the traditional roles of lawyers in the process, and identifies how mediation legislation will affect the role of lawyers

Socio-economic development, income inequality and redistribution

Tackling the issue of income equity through redistribution consists of a discussion about the extent and forms of redistribution. The study responds to the issue of income redistribution defined within the neoclassical welfare economy by addressing the research question concerning the relation of the selected areas of social policy (expenditure of social protection) and of socio-economic development (Human Development Index, Gini coefficient). The study uses a quantitative approach to the research question, statistically tests the relation between social protection expenditure and socio-economic development, and tests income inequality using the Pearson’s correlation coefficient. The results show that social protection expenditure on health care and old age had a positive impact on socio-economic development, assessed through the Human Development index; only social protection expenditure on disability had a negative impact on socio-economic development. Also, social protection expenditure on health care, on the disabled and on old age had a mainly negative impact on income inequity, based on the Gini coefficient

Identifying the ‘subnormal’ child in an age of expansion of special schooling and child science in the Netherlands (c.1945-1965)

Between c.1945 and 1965 across the West special education has grown and differentiated substantially. In the Netherlands this expansion ran parallel to the academic recognition and rapid development of the study of learning disabilities. How are these two processes related? This article argues that in this country child science and special education have mutually stimulated each other’s growth and development. The creation of new categories of special-needs children brought about a climate in which the study of learning disabilities and their treatment could flourish. This, in turn, produced further differentiation between children with learning difficulties. Soon problems of identification and categorisation of mentally ‘subnormal’ children proved too complicated to rely on intelligence testing and medical-psychological diagnosis alone. Educational prognosis, based on long-term observation and all kinds of testing, became the key to a child’s future at school and educationists instead of psychologists became the foremost keyholders

Potential Errors and Test Assessment in Software Product Line Engineering

Software product lines (SPL) are a method for the development of variant-rich software systems. Compared to non-variable systems, testing SPLs is extensive due to an increasingly amount of possible products. Different approaches exist for testing SPLs, but there is less research for assessing the quality of these tests by means of error detection capability. Such test assessment is based on error injection into correct version of the system under test. However to our knowledge, potential errors in SPL engineering have never been systematically identified before. This article presents an overview over existing paradigms for specifying software product lines and the errors that can occur during the respective specification processes. For assessment of test quality, we leverage mutation testing techniques to SPL engineering and implement the identified errors as mutation operators. This allows us to run existing tests against defective products for the purpose of test assessment. From the results, we draw conclusions about the error-proneness of the surveyed SPL design paradigms and how quality of SPL tests can be improved.Comment: In Proceedings MBT 2015, arXiv:1504.0192

Independence clustering (without a matrix)

The independence clustering problem is considered in the following formulation: given a set $S$ of random variables, it is required to find the finest partitioning $\{U_1,\dots,U_k\}$ of $S$ into clusters such that the clusters $U_1,\dots,U_k$ are mutually independent. Since mutual independence is the target, pairwise similarity measurements are of no use, and thus traditional clustering algorithms are inapplicable. The distribution of the random variables in $S$ is, in general, unknown, but a sample is available. Thus, the problem is cast in terms of time series. Two forms of sampling are considered: i.i.d.\ and stationary time series, with the main emphasis being on the latter, more general, case. A consistent, computationally tractable algorithm for each of the settings is proposed, and a number of open directions for further research are outlined