Round-robin tournaments with homogeneous rounds

We study single and double round-robin tournaments for n teams, where in each round a fixed number (g) of teams is present and each team present plays a fixed number (m) of matches in this round. In a single, respectively double, round-robin tournament each pair of teams play one, respectively two, matches. In the latter case the two matches should be played in different rounds. We give necessary combinatorial conditions on the triples (n,g,m) for which such round-robin tournaments can exist, and discuss three general construction methods that concern the cases m=1, m=2 and m=g−1. For n≤20 these cases cover 149 of all 173 non-trivial cases that satisfy the necessary conditions. In 147 of these 149 cases a tournament can be constructed. For the remaining 24 cases the tournament does not exist in 2 cases, and is constructed in all other cases. Finally we consider the spreading of rounds for teams, and give some examples where well-spreading is either possible or impossible

Cultural matching factors, child factors, and fostering factors associated with successful foster placement:An explorative study into the perspectives of unaccompanied refugee children, their foster carers and guardians

This paper presents findings from the baseline measurement of a longitudinal Dutch study focusing on cultural matching, child and fostering factors associated with the success of foster placements of unaccompanied refugee children. We assessed the placement from the perspectives of the children, their foster carers and their guardians. The children (n = 39) and their carers (n = 37) were visited at their homes, where they completed several questionnaires (e.g., SDQ, BIC, SLE, RATS, AHIMSA and questionnaires measuring bio/demographic variables, placement success and characteristics of the placement, including cultural characteristics). The guardians (n = 37) were asked to complete a digital questionnaire. The success of the placement was analysed using logistic regression models. The quality of the relationship between child and foster carer(s) exhibited an almost one-to-one relationship with ‘placement success’, for both the child model and the foster carer model. This means that one could also investigate the quality of the relationship between the child and carer to determine placement success. The regression analyses showed that, for children, cultural similarity between a child and their carers was of great importance. However, for foster carers and guardians, cultural similarity was less related to placement success. In addition, a higher score on prosocial behaviour by the child (SDQ self-report) was associated with more positive outcomes regarding placement success (child model). For foster carers, children’s externalizing behaviour (SDQ) was negatively correlated with the success of the placement (foster carer model). For guardians, a higher score on the quality of the caregiving environment (BIC-G) was associated with placement success (guardian model). Implications for research and practice are also discussed

Foster care for unaccompanied refugee children in the Netherlands; what about the placement success?

There is hardly any knowledge on the outcomes of foster placements of unaccompanied refugee children. Especially, knowledge on the stability of foster placements for unaccompanied refugee children is lacking. Because placements in regular foster care change and develop over time, including the occurrence of placement breakdowns, the need for a study focusing on the stability of foster placements for unaccompanied refugee children is indicated. This study explores the association between the success of foster placements for unaccompanied refugee children and cultural, child and fostering factors, and examines the stability of these factors over time

‘It can never be as perfect as home’:An explorative study into the fostering experiences of unaccompanied refugee children, their foster carers and social workers

Research shows that highly supportive living arrangements, such as foster care, can provide an environment that meets the needs of unaccompanied children (i.e. fewer internalizing problems, higher quality of the child-rearing environment). However, there is limited research into the experiences of these children in (cultural) foster care. The aim of this study is to explore the experiences of former unaccompanied refugee children and unaccompanied refugee children, their carers and social workers with regard to the foster placement. This cross-sectional qualitative study combined semi-structured interviews with questionnaires. In general, participants were satisfied with the foster placement. However, some children also reported negative experiences during their foster placement or felt somewhat uncomfortable, but they still rated the placement as successful. Children and carers valued the cultural similarity of the foster placement. Former unaccompanied children appreciated cultural similarity less. Overall, participants valued similarity of language the most. Several children did not feel at home in their foster placement. In most foster families, the pedagogical climate offered to children seemed adequate

Quantum chaos in 2D gravity

We present a quantitative and fully non-perturbative description of the ergodic phase of quantum chaos in the setting of two-dimensional gravity. To this end we describe the doubly non-perturbative completion of semiclassical 2D gravity in terms of its associated universe field theory. The guiding principle of our analysis is a flavor-matrix theory (fMT) description of the ergodic phase of holographic gravity, which exhibits $\mathrm{U}(n|n)$ causal symmetry breaking and restoration. JT gravity and its 2D-gravity cousins alone do not realize an action principle with causal symmetry, however we demonstrate that their {\it universe field theory}, the Kodaira-Spencer (KS) theory of gravity, does. After directly deriving the fMT from brane-antibrane correlators in KS theory, we show that causal symmetry breaking and restoration can be understood geometrically in terms of different (topological) D-brane vacua. We interpret our results in terms of an open-closed string duality between holomorphic Chern-Simons theory and its closed-string equivalent, the KS theory of gravity. Emphasis will be put on relating these geometric principles to the characteristic spectral correlations of the quantum ergodic phase.Comment: 49 pages, 2 appendices, 9 figures; v3: rewrote introduction, simplified Fig.