Residential projects are described as complex, dynamic systems that are subject to uncertainty. Cost performance is a fundamental challenge. As a result, project managers must adequately identify risks that might lead to cost overruns in residential construction projects. Simulation is noticed to be a useful technique for dealing with these complications. Therefore, this study developed a hybrid dynamic approach to study the effect of different risks on the cost performance of construction projects. The proposed approach combines system dynamics (SD) and discrete event simulation (DES), which can take into consideration the dynamics of the project environment, which contains various continuous influencing factors as well as the construction operations. The developed hybrid model is validated through serial model structure tests and model behavior tests, with the aid of data collected from a real construction project used in the simulation process. Based on the simulation results, it is concluded that the proposed hybrid dynamic approach is helpful to enhance the process performance by permitting construction managers to identify possible process improvement areas that traditional methods may miss.

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Background Studies have suggested that Sexual behaviors are common in children. More than 50% of children will engage in some type of sexual behavior before their 13th birthday. Sexual behaviors in children range from normal and developmentally appropriate to abusive and violent. In retrospective study of 339 child welfare and mental health professionals in which participants were asked about their own experiences before 13 years of age, 73% recalled engaging in sexual behaviors with other children, 34% recalled showing their genitals to another child, 16% recalled simulating intercourse with another child, and 5% recalled inserting an object in the vagina or rectum of another child Aim of the Work To observe the developmental course of describe normative sexual behaviors in 2- to 12-years-old Egyptian children and to assess the relative frequencies of different types of sexual behaviors in general outpatient clinic of pediatric hospital of Ain Shams University hospitals. Patients and Methods This is a Cross sectional analytical started on October 2018. Study conducted in pediatric hospital Ain Shams University hospitals. This present study aimed at analyzing the data of 500 children aged from 2 to 12 years old. Thirsty four refused to participate on sexual behaviour questions. Results A total of 500 questionnaires were done by parents of child vising clinic of pediatric hospital of Ain Shams university, 35 refused to participate in sexual behaviour questionnaire. It was divided in three groups. Preschool aged children from 2-6 years 254 child (50.8%), school aged children from 6-9 years 106 child (18.82%) & preadolescents from 10 to 12 years 140 child (24.014%). The study Included both 252 males and 248 females. The most sexual behaviours detected among children “sometimes” were touching genitals at home 111(22.2%), child asks about sexual acts 86 child (17.2%) & saying sexual words 80 (16%) and mostly repeated children was flirt with strangers 11(2.2%) & asking about sex more than other children 10 (2%). Conclusion In general, sexual behaviors in children two to five years of age are of a greater variety and are more common compared with the behaviors in children older than five years. once the child becomes aware of social rules regarding sexual behaviors in public, those behaviors become more covert. There is a need for further national studies in different settings, to help create a better understanding of what constitutes both normative and deviant sexual behaviour in children.