this paper describes a methodology in designing high-performance concrete for simply supported beams, using a hybrid optimization strategy based on a variable neighborhood search threshold acceptance algorithm. three strategies have been applied to discrete optimization of reinforced concrete beams: variable neighborhood descent (vnd), reduced neighborhood search (rns) and basic variable neighb...

Abstract Introduction Increasing evidence suggests the neighborhood social environment may be an important predictor of sleep, yet this has not been explored among urban American Indian and Alaska Native (AI/AN) adolescents, a population that faces significant health disparities due to exposure historic contemporary stressors. This study aimed examine association between sleep adolescents as we...

following the changes in the paradigm of urban studies in recent years, sustainability has become an increasingly important issue in the neighborhood’s planning and designing. however, this concept has originally been developed for american and european neighborhoods’ planning, it could also be customized for other neighborhoods’. additionally, in the neighborhood scale, the quality parameter f...

We are looking at a model of preferential attachment graphs that can evolve in five different ways. On any given iteration, a single vertex may be connected to the graph, a path may be connected to the graph, an edge may be added to the graph, an edge may be removed from a graph, or a vertex may be removed from a graph, with each option having a given probability of occurring. If a single verte...

Given an instance of the preferential attachment graph Gn = ([n], En), we would like to find vertex 1, using only ‘local’ information about the graph; that is, by exploring the neighborhoods of small sets of vertices. Borgs et. al gave an an algorithm which runs in time O(log n), which is local in the sense that at each step, it needs only to search the neighborhood of a set of vertices of size...

As the US population becomes more diverse in the 21st century, researchers face many conceptual and methodological challenges in working with diverse populations. We discuss these issues for racially and ethnically diverse youth, using Spencer's phenomenological variant of ecological systems theory (PVEST) as a guiding framework. We present a brief historical background and discuss recurring co...

Abstract. Based on the formation of triad junctions, the proposed mechanism generates networks that exhibit extended rather than single power law behavior. Triad formation guarantees strong neighborhood clustering and community-level characteristics as the network size grows to infinity. The asymptotic behavior is of interest in the study of directed networks in which (i) the formation of links...

The scale-free model of Barabási and Albert (BA) gave rise to a burst of activity in the field of complex networks. In this paper, we revisit one of the main assumptions of the model, the preferential attachment (PA) rule. We study a model in which the PA rule is applied to a neighborhood of newly created nodes and thus no global knowledge of the network is assumed. We numerically show that glo...

The suicide rate among American adolescents between the ages of 14-25 has dramatically increased during the last 50 years, and this fact has been the focus of extensive social-scientific investigation. To date, however, research focusing on the joint effects of mental health, family, and contextual-level predictors on adolescents' suicidal behaviors is scarce. Drawing on Durkheim's classic macr...