Tracking of square reference signals using internal model-based LQG robust controller for positioning of a micro-electro-mechanical systems micromirror

Micro & nano letters

article

Jiazheng Tan¹  Weijie Sun¹  John Yeow² 

[1] College of Automation Science and Engineering, South China University of Technology;Department of Systems Design Engineering, University of Waterloo

关键词: linear quadratic Gaussian control;    robust control;    position control;    micromirrors;    micromechanical devices;    control system synthesis;    square reference signal tracking;    internal model-based LQG robust controller;    microelectromechanical systems micromirror positioning;    Lorentz force-based polymer hard-magnetic micromirror;    optical switch application;    robust control design;    linear quadratic Gaussian method;    internal model principle;    positioning performances;    noise rejection ability;   

DOI  :  10.1049/mnl.2017.0681

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

Despite available effective contraception methods, unintended pregnancy remains a significant health issue. Emergency contraception (EC) is used to prevent pregnancy after an unprotected or inadequately protected sexual intercourse. The aim of this study was to evaluate knowledge and personal experience with EC among reproductive-aged women. A prospective survey among a sample of Portuguese women at reproductive age was performed. The survey was anonymous, voluntary and included questions regarding sociodemographic characteristics, obstetrical history, known emergency contraception methods, timing to use EC, personal experience and efficacy of available methods. After completing the survey, participants were offered written information about EC. A total of 92 women participated on the survey but 3 were excluded due to incorrect filling. Mean age was 30.52 years and most were single, multiparous and with no previous abortions. Awareness rate of EC was 95.5% but only 56.4% knew that it prevented pregnancy. Just 16.5% stated that both hormonal oral method and IUD were the available methods and 67% believed that it was effective within 1 day after unprotected sexual intercourse. EC was previously used by 29.4% and to 65.9% participants the hormonal oral method was considered the most effective. Over 90% said that EC does not protect against sexually transmitted infections. Despite the high rate of awareness of EC our population had some limitations concerning the purpose and different forms of EC as well as the proper time limit to use it. Educating reproductive-aged women and health care providers about EC is important.

【 授权许可】

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