Joint X̄ and R charts with variable parameters

Recent studies have shown that the X̄chart with variable parameters (Vp X̄ chart) detects process shifts faster than the traditional X̄ chart. This article extends these studies for processes that are monitored by both, X̄ and R charts. Basically, the X̄ and R values establish if the control should or should not be relaxed. When the X̄ and R values fall in the central region the control is relaxed because one will wait more to take the next sample and/or the next sample will be smaller than usual. When the X̄ or R values fall in the warning region the control is tightened because one will wait less to take the next sample and the next sample will be larger than usual. The action limits are also made variable. This paper proposes to draw the action limits (for both charts) wider than usual, when the control is relaxed and narrower than usual when the control is tightened. The Vp feature improves the joint X̄ and R control chart performance in terms of the speed with which the process mean and/or variance shifts are detected. © 1998 IIE.

Multifunctional current reference generation strategy for grid-tied power electronic converter

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sorovacinação antirrabica: aspectos epidemiologicos e implicações para assistência de enfermagem

This study was developed with the purpose to search for relevant knowledge concerning nursing care for individuals exposed to the rabies virus and submitted to post-exposure anti-rabies serovaccination. The authors aimed at evaluating the epidemiological aspects of accidents involving household and wild animals occurring in 2007 and patients assisted at a reference hospital located in the mid-southern region of São Paulo State. They also aimed at identifying the relevance of nurses' actions by describing aspects of care provision. The method adopted was exploratory, retrospective and descriptive of the epidemiological aspects of the accidents and of the care provided to these patients by referring to information in their medical charts. Fifty-one charts of patients aged 17 to 81 years, considered to be at risk and with indication for post-exposure prophylaxis against human rabies were evaluated. It was found that nursing care provision to these patients presents low complexity although it requires properly trained professionals. It was possible to identify the relevance of nurses' actions in care provision and procedures related to anti-rabies prophylaxis; however, consistent information concerning nursing care was not observed.