Network formation under mutual consent and costly communication

We consider two different approaches to describe the formation of social networks under mutual consent and costly communication. First, we consider a network-based approach; in particular Jackson–Wolinsky’s concept of pairwise stability. Next, we discuss a non-cooperative game-theoretic approach, through a refinement of the Nash equilibria of Myerson’s consent game. This refinement, denoted as monadic stability, describes myopically forward looking behavior of the players. We show through an equivalence that the class of monadically stable networks is a strict subset of the class of pairwise stable networks that can be characterized fully by modifications of the properties defining pairwise stability.

A Lagrangian approach for modeling road collisions using second-order models of traffic flow

In [M. Herty, A. Klein, S. Moutari, V. Schleper, and G. Steinaur, IMA J. Appl. Math., 78(5), 1087–1108, 2013] and [M. Herty and V. Schleper, ZAMM J. Appl. Math. Mech., 91, 763–776, 2011], a macroscopic approach, derived from fluid-dynamics models, has been introduced to infer traffic conditions prone to road traffic collisions along highways’ sections. In these studies, the governing equations are coupled within an Eulerian framework, which assumes fixed interfaces between the models. A coupling in Lagrangian coordinates would enable us to get rid of this (not very realistic) assumption. In this paper, we investigate the well-posedness and the suitability of the coupling of the governing equations within the Lagrangian framework. Further, we illustrate some features of the proposed approach through some numerical simulations.

Molecular effects in the ionization of N-2, O-2, and F-2 by intense laser fields

In this paper we study the response in time of N2, O2, and F2 to laser pulses having a wavelength of 390 nm. We find single-ionization suppression in O2 and its absence in F2, in accordance with experimental results at lambda= 800 nm. Within our framework of time-dependent density functional theory we are able to explain deviations from the predictions of intense-field many-body S-matrix theory (IMST). We confirm the connection of ionization suppression with destructive interference of outgoing electron waves from the ionized electron orbital. However, the prediction of ionization suppression, justified within the IMST approach through the symmetry of the highest occupied molecular orbital (HOMO), is not reliable since it turns out that—e.g., in the case of F2—the electronic response to the laser pulse is rather complicated and does not lead to dominant depletion of the HOMO. Therefore, the symmetry of the HOMO is not sufficient to predict ionization suppression. However, at least for F2, the symmetry of the dominantly ionized orbital is consistent with the nonsuppression of ionization.

New Views on Effect of Recycled Aggregates on Concrete Compressive Strength

This paper presents an in-depth study on the effect that composition and properties of recycled coarse aggregates from previous concrete structures, together with water/cement ratio (w/c) and a replacement ratio of coarse aggregate, have on compressive strength, its evolution through time, and its variability. A rigorous approach through statistical inference based on multiple linear regression has identified the key factors. A predictive equation is given for compressive strength when recycled coarse aggregates are used. The w/c and replacement ratio are the capital factors affecting concrete compressive strength. Their effect is significantly modified by the properties and composition of the recycled aggregates used. An equation that accurately predicts concrete compressive strength in terms of these parameters is presented. Particular attention has been paid to the complex effect that old concrete and adhered mortar have on concrete compressive strength and its mid-term evolution. It has been confirmed that the presence of contaminants tends to increase variability of compressive strength values.

Platform Competition as Network Contestability

Recent research in industrial organisation has investigated the essential place that middlemen have in the networks that make up our global economy. In this paper we attempt to understand how such middlemen compete with each other through a game theoretic analysis using novel techniques from decision-making under ambiguity.
We model a purposely abstract and reduced model of one middleman who provides a two-sided platform, mediating surplus-creating interactions between two users. The middleman evaluates uncertain outcomes under positional ambiguity, taking into account the possibility of the emergence of an alternative middleman offering intermediary services to the two users.
Surprisingly, we find many situations in which the middleman will purposely extract maximal gains from her position. Only if there is relatively low probability of devastating loss of business under competition, the middleman will adopt a more competitive attitude and extract less from her position.

A Pension for Injured Victims of the Troubles: Reparations or Reifying Victim Hierarchy?

Reparations have been often used victim-centred measures to redress both private harm and gross violations of human rights. However, with the increasing occurrence of internal armed conflict and political violence, identities of victims and perpetrators in protracted conflicts can become blurred for some individuals. In countries like Peru and Northern Ireland that have suffered protracted violence, victimhood has been contested around which individuals are seen as innocent and deserving to exclude any members of non-state armed groups from claiming reparations. This article explores the issue of a proposed bill on a pension for injured victims of the Troubles in Northern Ireland. It identifies that there is no consistent state practice or human rights jurisprudence in this area, but instead offers a more complex approach through four models that can grapple with the seeming diametrically opposed victimhood and responsibility, by including victimised-perpetrators in reparations programmes such as that proposed for a pension of seriously injured victims in Northern Ireland.

Revisioning assessment through a children’s rights approach: implications for policy, process and practice

The linkage between the impact of assessment and compliance with children’s rights is a connection, which although seemingly obvious, is nonetheless rarely made, particularly by governments, which, as signatories to the relevant human rights treaties, have the primary responsibility for ensuring that educational practice is compatible with international children’s rights standards. While some jurisdictions are explicit about an adherence to children’s rights frameworks in general policy documentation, such a commitment rarely features when the focus is on assessment and testing. Thus, in spite of significant public and academic attention given to the consequences of assessment for children and governments committed to working within children’s rights standards, the two are rarely considered together. This paper examines the implications for the policy, process and practice of assessment in light of international human rights standards. Three key children’s rights principles and standards are used as a critical lens to examine assessment policy and practice: (1) best interests; (2) non-discrimination; and (3) participation. The paper seeks new insights into the complexities of assessment practice from the critical perspective of children’s rights and argues that such standards not only provide a convenient benchmark for developing, implementing and evaluating assessment practices, but also acknowledge the significance of assessment in the delivery of children’s rights to, in and through education more generally.

Web Services and Incerta Spiriti: A Game Theoretic Approach to Uncertainty

A web-service is a remote computational facility which is made available for general use by means of the internet. An orchestration is a multi-threaded computation which invokes remote services. In this paper game theory is used to analyse the behaviour of orchestration evaluations when underlying web-services are unreliable. Uncertainty profiles are proposed as a means of defining bounds on the number of service failures that can be expected during an orchestration evaluation. An uncertainty profile describes a strategic situation that can be analyzed using a zero-sum angel-daemon game with two competing players: an angel a whose objective is to minimize damage to an orchestration and a daemon d who acts in a destructive fashion. An uncertainty profile is assessed using the value of its angel daemon game. It is shown that uncertainty profiles form a partial order which is monotonic with respect to assessment.

Family, state, class and solidarity: re-conceptualising intergenerational solidarity through the grounded theory approach

The relationship between class and intergenerational solidarities in the public and private spheres calls for further conceptual and theoretical development. This article discusses the findings from the first wave of a qualitative longitudinal study entitled Changing Generations, conducted in Ireland in 2011–2012, comprising 100 in-depth interviews with men and women across the age and socioeconomic spectrums. Constructivist grounded theory analysis of the data gives rise to the following postulates: (1) intergenerational solidarity at the family level is strongly contoured by socioeconomic status (SES); (2) intergenerational solidarity evolves as family generations observe each others’ practices and adjust their expectations accordingly; (3) intergenerational solidarity within families is also shaped by the public sphere (the welfare state) that generates varying expectations and levels of solidarity regarding State supports for different age groups, again largely dependent on SES; (4) the liberal welfare state context, especially at a time of economic crisis, enhances the significance of intergenerational solidarity within families. We conclude by calling for research that is attuned to age/generation, gender and class, and how these operate across the family and societal levels.

A Game-Theoretic Approach for Threats Detection and Intervention in Surveillance

Threat prevention with limited security resources is a challenging problem. An optimal strategy is to eectively predict attackers' targets (or goals) based on current available information, and use such predictions to prevent (or disrupt) their planned attacks. In this paper, we propose a game-theoretic framework to address this challenge which encompasses the following three elements. First, we design a method to analyze an attacker's types in order to determine the most plausible type of an attacker. Second, we propose an approach to predict possible targets of an attack and the course of actions that the attackers may take even when the attackers' types are ambiguous. Third, a game-theoretic based strategy is developed to determine the best protection actions for defenders (security resources).