Sensitivity of Space Station alpha joint robust controller to structural modal parameter variations

The photovoltaic array sun tracking control system of Space Station Freedom is described. A synthesis procedure for determining optimized values of the design variables of the control system is developed using a constrained optimization technique. The synthesis is performed to provide a given level of stability margin, to achieve the most responsive tracking performance, and to meet other design requirements. Performance of the baseline design, which is synthesized using predicted structural characteristics, is discussed and the sensitivity of the stability margin is examined for variations of the frequencies, mode shapes and damping ratios of dominant structural modes. The design provides enough robustness to tolerate a sizeable error in the predicted modal parameters. A study was made of the sensitivity of performance indicators as the modal parameters of the dominant modes vary. The design variables are resynthesized for varying modal parameters in order to achieve the most responsive tracking performance while satisfying the design requirements. This procedure of reoptimization design parameters would be useful in improving the control system performance if accurate model data are provided

Power optimal single-axis articulating strategies

Power optimal single axis articulating PV array motion for Space Station Freedom is investigated. The motivation is to eliminate one of the articular joints to reduce Station costs. Optimal (maximum power) Beta tracking is addressed for local vertical local horizontal (LVLH) and non-LVLH attitudes. Effects of intra-array shadowing are also presented. Maximum power availability while Beta tracking is compared to full sun tracking and optimal alpha tracking. The results are quantified in orbital and yearly minimum, maximum, and average values of power availability

Rubrics in Nursing Education

Evaluating assignments or course work is a challenging job for faculty of nursing. In order to avoid the dilemmas of evaluation, nurse educators use rubrics as an evaluation tool. In educational technology, rubric refers to „performance standard‟ for a student population. A rubric is defined as an assessment tool that lays out the set standards and criteria to assess a performance, assignment or behavior. The four essential components of a rubric are task description, scale of achievement, dimensions & description of dimensions. Various types of scoring rubrics are available. The type of rubric chosen for assessment depends on the task being evaluated and the needs of the assessor. Holistic rubrics, analytic rubrics, generic rubrics, specific rubrics are the different types of rubrics. In nursing education, rubrics has got wide range of applications such as to; assess clinical skills, grade assignments, evaluate clinical competency and analyze presentations. Rubrics helps to define "quality performance” and promote awareness on critical components in a performance. Rubrics not only act as an evaluation tool for instructors, but also act as a feedback proforma for students. Rubrics are vital tools that can be utilized to solve the problem of subjectivity in evaluation. Rubrics provide consistency in evaluation, reduces subjectivity and enhances objectivity

Integration of Evidence-Based Practice in Nursing Education

Evidence based practice (EBP) has gained momentum globally, to provide effective and efficient health care. Although EBP has evolved to a great extent over the last two decades and is accepted as an important concept by all health care professionals, its integration in practice is still challenging. Integration of EBP in nursing profession both in nursing practice and nursing education is an important issue. This article describes the experience of the authors in integrating evidence based practice in nursing education in Manipal University. It focuses on the training of nurse educators in EBP, alignment of EBP in curriculum and EBP practicum in curriculum so as to enable a nurse to identify evidences, make appropriate clinical decisions and utilize EBP in rendering scientific and quality patient care