Variability affects the performance and power of a circuit. Along with static variations, dynamic variations, which occur during chip operation, necessitate a safety margin. The safety margin makes it difficult to meet the target performance within a limited power budget. This research explores methodologies to minimize the safety margin, thereby improving the energy efficiency of a system. The safety margin can be reduced by either minimizing the variation or adapting to the variation. This research explores three different methods to compensate for variations efficiently. First, post-silicon tuning methods for minimizing variations in 3D ICs are presented. Design methodologies to apply adaptive voltage scaling and adaptive body biasing to 3D ICs and the associated circuit techniques are explored. Second, non-design-intrusive circuit techniques are proposed for adaptation to dynamic variations. This work includes adaptive clock modulation and bias-voltage generation techniques. Third, design-intrusive methods to eliminate the safety margin are proposed. The proposed methodologies can prevent timing-errors in advance with a minimized performance penalty. As a result, the methods presented in this thesis minimize static variations and adapt to dynamic variations, thereby, enabling robust low-power operation of digital systems.

Estimation and measurement of the size of software is crucial for project management activities. Functional size measurement is one of the most frequently used methods to measure size of software and COSMIC is one of the popular methods for functional size measurement. Although precise size measurement is critical, the results may differ because of the errors made in the measurement process. The erroneous measurement results cause lack of confidence for the methods as well as reliability problems for effort and cost estimations. This research proposes an error prevention model for COSMIC Functional Size Measurement method to increase the reliability of the measurements. The prevention model defines data movement patterns for different types of the functional processes and a cardinality table to prevent errors. We validated the prevention model with two different case studies and observed that it can decrease errors up to 90% in our case studies.

Medication errors cause harm, yet most of them are preventable (Institute of Medicine, 2006). Nurses spend 40% of their time administering medications; therefore they play a key role in the reduction of medication errors. Little empirical evidence has been collected about the effectiveness of nursing education in reducing medication errors committed by nursing students. Traditional educational interventions focus on the five rights of medication administration; however, the literature shows that interventions focused on instilling a culture of safety have a greater impact on reducing medication errors. The purpose of this article is to review educational strategies that have been implemented and tested in pre-licensure nursing programs to reduce medication errors committed by nursing students.

Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-04-20T14:54:29Z No. of bitstreams: 1 SÉRGIO EDOARDO CORREA DIAS – DISSERTAÇÃO (PPGEE) 2017.pdf: 7223425 bytes, checksum: 1e47ec642d6afb7c8afce2e856badae9 (MD5) / Made available in DSpace on 2018-04-20T14:54:29Z (GMT). No. of bitstreams: 1 SÉRGIO EDOARDO CORREA DIAS – DISSERTAÇÃO (PPGEE) 2017.pdf: 7223425 bytes, checksum: 1e47ec642d6afb7c8afce2e856badae9 (MD5) Previous issue date: 2017-03-24 / Em sistemas críticos, o erro humano e suas implicações constituem um desafio constan-te para pesquisadores, engenheiros e demais atores envolvidos direta ou indiretamente na execução dos processos. No contexto das subestações de transmissão de energia o erro introduzido durante a execução de manobras é impactante dado que eleva o risco para a integridade de pessoas e do sistema. Este trabalho propõe uma estratégia, apoiada por ferramenta de software, que visa a redução de erros na fase de execução de mano-bras sobre o sistema elétrico, em particular sobre o sistema de automação das subesta-ções de transmissão de energia. A estratégia é fundamentada no estudo do erro e na me-todologia de execução de manobras adotada na Companhia Hidroelétrica do São Fran-cisco – CHESF. A estratégia proposta para prevenção do erro consiste em guiar o passo-a-passo da execução de manobras de rotina e é voltada para as ações executadas através do sistema supervisório. Embora a ferramenta desenvolvida possa executar, sobre o supervisório, uma manobra selecionada pelo operador sem sua intervenção, a estratégia prevê apenas a execução guiada, deixando graus de liberdade para o operador intervir durante eventos imprevistos. Para validação da estratégia foram realizados testes opera-dores de uma subestação de transmissão de energia, os quais simularam a execução de manobras utilizando a ferramenta. Os testes objetivaram avaliar tanto a eficácia da es-tratégia proposta quanto a eficiência da ferramenta quando comparada à realização das manobras sem sua utilização. Os resultados preliminares são promissores. / In critical systems, human error and its implications constitute a constant challenge for researchers, engineers and other actors involved directly or indirectly in the operation of those systems. In the context of power transmission substations the error introduced during causes an impact impacting since it increases the risk levels to the integrity of people and system. This work proposes a strategy, supported by a software tool, which aims to reduce human errors during manoeuvres on the electric system, specially the automation system of the power transmission substations. The strategy is based on the study of the human error and also on the methods employed when performing manoeu-vres at CHESF, a Brazilian Hydroelectric Company at the São Francisco (river). This error prevention strategy consists of guiding the step-by-step performance of routine manoeuvres and is restricted to actions performed through the supervisory system. Alt-hough the developed tool could completely automate a manoeuvre selected by the oper-ator, without intervention, the strategy ensures the degrees of freedom necessary for intervention during unforeseen events. To validate the strategy, tests were performed with the participation of real operators from an energy transmission substation of CHESF. Those tests simulated the execution of manoeuvres adopting the proposed strategy and associated software tool. The tests aimed to evaluate both the effectiveness of the strategy and the efficiency of the tool, when compared to performing manoeuvres without its support. The preliminary results are promising.

Science has been perceived as difficult to learn because of its nature and the methods by which it is usually taught. Most first-year science students entering higher education in South Africa today come from disadvantaged teaching and learning backgrounds. These students bring different “knowledge, skills or abilities” into the learning process. This knowledge, referred to as prior knowledge – or what the student already knows – is the single most important factor influencing learning (Ausubel, 1968). It is on the basis of this influence of prior knowledge on learning that the focus in this study is on understanding its manifestation in learning. Prior knowledge has both facilitating and inhibiting effects in learning. However, the focus in this study was only on inhibiting effects of prior knowledge on learning. To better understand prior knowledge qualitative methods (interview, observation, document review and the prior knowledge state test) were used. The aim was to specifically establish how students used their understanding of selected acid-base concepts and processes to construct understanding and to generate meaning of new concepts and/or knowledge. The study managed to highlight important aspects of the quality of prior knowledge and their manifestation in learning. The findings generally indicated that: <ul> <li>The quality of the knowledge that students possessed was in most instances incomplete. That is, in their description of concepts, students preferred to use summary and informal descriptions without understanding the meaning of the concepts they were describing.</li> <li> The quality of knowledge (e.g. incomplete knowledge) affected their ability to construct understanding and/or generate meaning as this knowledge was insufficient to access for the construction of scientifically valid meanings of concepts.</li> <li>The quality of students’ knowledge impeded their ability to reflect and/or to be aware of the knowledge they possessed. This made it difficult for students to access knowledge and to restructure it in order to construct new knowledge or prevent errors in their learning.</li> </ul> The study culminated in the development of a framework that may in future be used to assess prior knowledge and enhance meaningful teaching and learning based on the quality of students’ prior knowledge. / Thesis (PhD)--University of Pretoria, 2008. / Curriculum Studies / unrestricted