Compound Constructions of Broadcast Networks

Compound methods have been shown to be very e#ective in the construction of broadcast graphs. Compound methods generate a large broadcast graph by combining multiple copies of a broadcast graph G using the structure of another broadcast graph H . Node deletion is also allowed in some of these methods. The subset of connecting nodes of G has been de#ned as solid h-cover by Bermond, Fraigniaud and Peters, and center node set by Weng and Ventura. This article shows that the two concepts are equivalent. We also provide new properties for center node sets, including bounds on the minimum size of a center node set, show how to reduce the number of center nodes of a broadcast graph generated by a compound method, and propose an iterative compounding algorithm that generates the sparsest known broadcast graphs in many cases. ? 1999 Elsevier Science B.V. All rights reserved

Construction of Time-Relaxed Minimal Broadcast Networks

In broadcasting, or one-to-all communication, a message originally held in one node of the network must be transmitted to all the other nodes. A minimal broadcast network is a communication network that can transmit a message originated at any node to all other nodes of the network in minimum time. In this paper, we present a compound method to construct sparse, time-relaxed, minimal broadcast networks (t-mbn), in which broadcasting can be accomplished in slightly more than the minimum time. The proposed method generates a new network by connecting a subset of nodes from several copies of a t1 -mbn using the structure of another t2 -mbn. The objective is to construct a network as sparse as possible satisfying the desired broadcasting time constraint. Computational results illustrate the effectiveness of the proposed method.

Lifetime prevalence, sociodemographic predictors, and comorbidities of oppositional defiant disorder: The national epidemiology of iranian child and adolescent psychiatric disorders (IRCAP)

Objective: This was the first national epidemiological study on oppositional defiant disorder (ODD) in Iran, which provided new information about the prevalence, comorbidities, and sociodemographic predictors of ODD. Methods: Data from a face-to-face household survey of 30,532 children and adolescents aged 6-18 years were collected from across all 31 provinces of Iran using a multistage cluster sampling design. The Persian version of the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children � Present and Lifetime Version (K-SADS-PL) was used in this study. Results: The lifetime prevalence of ODD was found to be 3.9. ODD was significantly more common in boys than girls and appeared in late adolescence more frequently than in childhood. A lower prevalence of ODD was found among participants who lived in rural areas. ODD is highly likely to co-occur with attention deficit hyperactivity disorder, separation anxiety disorder, generalized anxiety disorder, and depressive disorders. Conclusions: The findings of this national population-based study confirm and extend previous findings on the prevalence, comorbidities, and sociodemographic predictors of ODD. © 2020, Associacao Brasileira de Psiquiatria. All rights reserved

Prevalence, comorbidity and predictors of anxiety disorders among children and adolescents

Childhood anxiety may lead to serious health consequences in later life. The present study provides the prevalence, comorbidity, and predictors of anxiety disorders among children and adolescents. This was a cross-sectional national project that was implemented on 28,698 children and adolescents in Iran. Participants entered the study by multistage cluster sampling with an equal number of each gender and three age groups (6-9, 10-14, and 15-18 years) within each cluster. The tools used in this research were the demographic questionnaire and K-SADS-PL. To analyze the data logistic regression and chi-square tests were used in SPSS (ver. 16). The prevalence of anxiety disorder in children and adolescents was 13.2 in boys and 15.1 in girls. Furthermore, gender, age, place of residence and history of psychiatric hospitalization of parents could predict anxiety disorders. Anxiety disorders had comorbidity with behavioral disorders, neurodevelopmental disorders, mood disorders, psychotic disorders, substance abuse disorders, and elimination disorders. According to our findings in this study, anxiety disorders affect the performance, health and life of children and adolescents, identifying the childhood anxiety, as well as finding diseases that are associated with anxiety disorders, can help in the prevention of the disorder. © 2020 Elsevier B.V