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Polyzois, Dimos J., Raftoyiannis, Ioannis G., and Ungkurapinan, Nibong
Subjects
*DYNAMIC testing of materials, *FIBER-reinforced ceramics, *WIND turbines, *MECHANICAL engineering
Abstract
Abstract: An extensive research project is currently being carried out at the University of Manitoba, Canada, involving the development of glass fiber-reinforced polymer (GFRP) wind turbine towers. The towers consist of multi-cell segments, each segment constructed from eight filament wound cells jointed together with resin applied over their interface. The present paper mainly addresses the static and dynamic characteristics, such as failure static loads, modes of failure, fundamental frequencies and periods of such segmented composite towers. Both experimental and numerical results are presented. The experimental investigation involved the testing of two jointed scaled towers. These specimens had a total height of 4.88-m (16-ft) and were tested as cantilevers under static and dynamic loading. The testing was conducted at the W.R. McQuade Structural Engineering Laboratory of the University of Manitoba. Finally, finite element models were developed to analyze the structural behavior, static and dynamic, of single and multi-cell composite segments and towers. The results from the finite element models under static loading were validated through comparison with the experimental results. [Copyright &y& Elsevier]
Olver, Mark E., Beggs Christofferson, Sarah M., Grace, Randolph C., and Wong, Stephen C. P.
Subjects
SEX offenders, RISK assessment, RISK-taking behavior in adolescence, RECIDIVISM rates, REHABILITATION of sex offenders, LOGISTIC regression analysis, ATTITUDE (Psychology)
Abstract
We examined the use of risk-change information in sexual offender risk assessments featuring the Violence Risk Scale–Sexual Offender version (VRS-SO), a sex offender risk assessment and treatment planning tool. The study featured a combined international sample of 539 sex offenders followed up an average of 15.5 years post-release. Pre- and posttreatment VRS-SO ratings were amalgamated from two treated samples of sex offenders from Canada and New Zealand. Analyses focused on examinations and applications of change data and its relationship to sexual and violent recidivism. VRS-SO change scores were significantly associated with decreases in these outcome criteria with, and without, controlling for indicators of pretreatment risk (e.g., Static-99R score) and individual differences in follow-up time. Applications of logistic regression using fixed 5-year follow-ups generated estimated rates of sexual and violent recidivism at different VRS-SO score thresholds. The use of logistic regression demonstrated a clinically useful and systematic means of combining risk and change information into posttreatment risk appraisals. Implications for the use of change information in the assessment and management of sexual offender risk are discussed. [ABSTRACT FROM PUBLISHER]