Survivable Virtual Topology Routing under Shared Risk Link Groups in WDM Networks

Network survivability is one of the most important issues in the design of optical WDM networks. In this work we study the problem of survivable routing of a virtual topology on a physical topology with Shared Risk Link Groups (SRLG). The survivable virtual topology routing problem against single-link failures in the physical topology is proved to be NP-complete in [1]. We prove that survivable virtual topology routing problem against SRLG/node failures is also NP-complete. We present an improved integer linear programming (ILP) formulation (in comparison to [1]) for computing the survivable routing under SRLG/node failures. Using an ILP solver, we computed the survivable virtual topology routing against link and SRLG failures for small and medium sized networks efficiently. As even our improved ILP formulation becomes intractable for large networks, we present a congestion-based heuristic and a tabu search heuristic (which uses the congestion-based heuristic solution as the initial solution) for computing survivable routing of a virtual topology. Our experimental results show that tabu search heuristic coupled with the congestion based heuristic (used as initial solution) provides fast and near-optimal solutions.

Is Everyone Rated Equal? An Examination of Factors Related to Sexual Risk in Ethnically Diverse Male Adolescents Who Have Sexually Offended

As the juvenile justice system has evolved, there has been a need for clinicians to make judgments about risk posed by adolescents who have committed sexual offenses. There are inherent difficulties in attempting to assess risk for violence among adolescents due to the developmental changes taking place and the absence of well-validated instruments to guide risk prediction judgments. With minority groups increasing in numbers in the U.S., it is likely that professionals will encounter minority individuals when conducting risk assessments. Overall questions regarding race/ethnicity have been neglected and there are few if any published research that explores risk factors with minority juvenile sex offenders. The present study examined whether differences exist between Caucasian and racial/ethnic minority adolescent sexual offenders on four risk assessment measures (J-SORRAT-II, J-SOAP-II, SAVRY, and ERASOR). The sample of 207 male adolescent sexual offenders was drawn from treatment facilities in a Midwestern state. Overall results indicated that minority adolescent sex offenders had fewer risk factors endorsed than Caucasian youth across all risk assessment tools. Exploration of interactions between race and factors such as: family status, exposure to family violence, and family history of criminality upon the assessment tools risk ratings yielded non-significant findings. Limitations, suggestions for future directions, and clinical implications are discussed.