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Summary: This paper addresses the problem of switching control for systems subject to external disturbances that vary over multiple frequency ranges. Specifically, two different scenarios of disturbance injection are considered; namely, the disturbance may switch between different prescribed frequency ranges, subject to an average dwell time setting, or the disturbance may reside within one of the frequency ranges. To address these scenarios, a disturbance‐triggered control scheme is developed that divides the entire frequency range into low‐, mid‐, and high‐frequency ranges. This scheme ensures closed‐loop stability under average dwell time frequency‐range switching and achieves H∞$$ {H}_{\infty } $$ performance when operated under individual frequency ranges. Synthesis conditions in matrix inequalities are derived to characterize the switching control, and an iterative algorithm is proposed for finding a desired set of controller gains. Finally, two examples are presented to illustrate the effectiveness of the proposed control method. [ABSTRACT FROM AUTHOR]

Background: Skin cancer survivors are more vulnerable to subsequent skin cancers and other malignancies, but previous studies have not examined in detail their sun protection behavior prevalence by sociodemographic factors. We aimed to understand the sociodemographic disparities in the prevalence of three important types of sun protection behaviors: using sunscreen, seeking shade, and wearing protective clothing, among skin cancer survivors and those without skin cancer history. Methods: We used the 2015 U.S. National Health Interview Survey to analyze 29,523 participants, of which 772 were skin cancer survivors and 28,751 were those without skin cancer history. We assessed overall and specific sun protection behavior prevalence based on using sunscreen, seeking shade, and wearing protective clothing. Weighted Poisson regression was used to estimate prevalence ratios. Results: Melanoma and nonmelanoma skin cancer survivors had similar overall sun protection behavior (p >.05). Among all skin cancer survivors, 36.0% infrequently used sunscreen, 50.2% infrequently wore protective clothing, 47.8% infrequently sought shade, and 30.0% lacked frequent overall sun protection, which significantly differed from those without skin cancer history (p <.0001). The prevalence of frequent overall sun protection behavior was lower for those who were younger at survey, males, less educated, single or never married, or lived in poverty, regardless of their skin cancer history (p <.01). Conclusions: By identifying subpopulations with higher prevalence of infrequent sun protection among those with or without skin cancer history, our findings may encourage efforts to reduce sociodemographic disparities in sun protection behaviors and promote primary and tertiary skin cancer prevention. [ABSTRACT FROM AUTHOR]