Modeling and analysis of a zipping elastomeric actuator

This thesis introduces and analyzes a dielectric elastomer actuator (DEA) working in zipping mode. Electrostatic zipping is a very familiar actuation principle used in silicon micro-electro-mechanical systems. With lower voltage supply, electrostatic zipping can provide great performance for forces and displacements of an elastic membrane. Applying this principle to dielectric elastomers, the softness of the material will provide better compliance compared to silicon materials. After the presentation of an analytical model, this thesis investigates how system geometry and elastomer pre-tensioning affect system response. Results highlight how a proper selection of system parameters makes it possible to improve system regulation and reduce operating voltage requirements. Potential applications of zipping DEAs are for microfluidic control and electro-forming.

Methods of visualization and analysis of cardiac depolarization in the three dimensional space

The master thesis presents methods for intellectual analysis and visualization 3D EKG in order to increase the efficiency of ECG analysis by extracting additional data. Visualization is presented as part of the signal analysis tasks considered imaging techniques and their mathematical description. Have been developed algorithms for calculating and visualizing the signal attributes are described using mathematical methods and tools for mining signal. The model of patterns searching for comparison purposes of accuracy of methods was constructed, problems of a clustering and classification of data are solved, the program of visualization of data is also developed. This approach gives the largest accuracy in a task of the intellectual analysis that is confirmed in this work. Considered visualization and analysis techniques are also applicable to the multi-dimensional signals of a different kind.

Disaggregated financial data and analysis for the domestic motor vehicle manufacturers. NHTSA technical report.

National Highway Traffic Safety Administration, Washington, D.C.

National-Regional Impact Evaluation System : structure, performance, and application of a bottom-up interregional econometric model /

At head of title: NRIES.

Some key problems concerning the specification, development and use of task identification and analyses /

Photocopy.

Guidelines for air quality maintenance planning and analysis.

Vol. 7: second ed., 1975.

Ion beam modification and analysis of metal/polymer bi-layer thin films

A set of varying-thickness Au-films were thermally evaporated onto poly(styrene-co-acrylonitrile) thin film surfaces. The Au/PSA bi-layer targets were then implanted with 50 keV N+ ions to a fluence of 1 × 1016 ions/cm2 to promote metal-to-polymer adhesion and to enhance their mechanical and electrical performance. Electrical conductivity measurements of the implanted Au/PSA thin films showed a sharp percolation behavior versus the pre-implant Au-film thickness with a percolation threshold near the nominal thickness of 44 Å. The electrical conductivity results are discussed along with the film microstructure and the elemental diffusion/mixing within the Au/PSA interface obtained by scanning electron microscopy (SEM) and ion beam analysis techniques (RBS and ERD).

The effects of task complexity and practice on dual-task interference in visuospatial working memory

Although the n-back task has been widely applied to neuroimagery investigations of working memory (WM), the role of practice effects on behavioural performance of this task has not yet been investigated. The current study aimed to investigate the effects of task complexity and familiarity on the n-back task. Seventy-seven participants (39 male, 38 female) completed a visuospatial n-back task four times, twice in two testing sessions separated by a week. Participants were required to remember either the first, second or third (n-back) most recent letter positions in a continuous sequence and to indicate whether the current item matched or did not match the remembered position. A control task, with no working memory requirements required participants to match to a predetermined stimulus position. In both testing sessions, reaction time (RT) and error rate increased with increasing WM load. An exponential slope for RTs in the first session indicated dual-task interference at the 3-back level. However, a linear slope in the second session indicated a reduction of dual-task interference. Attenuation of interference in the second session suggested a reduction in executive demands of the task with practice. This suggested that practice effects occur within the n-back ask and need to be controlled for in future neuroimagery research using the task.

Construction and analysis of a metagenomic library from an enhanced biological phosphorus removal biomass

The enhanced biological phosphorus removal (EBPR) process is regularly used for the treatment of wastewater, but suffers from erratic performance. Successful EBPR relies on the growth of bacteria called polyphosphate-accumulating organisms (PAOs), which store phosphorus intracellularly as polyphosphate, thus removing it from wastewater. Metabolic models have been proposed which describe the measured chemical transformations, however genetic evidence is lacking to confirm these hypotheses. The aim of this research was to generate a metagenomic library from biomass enriched in PAOs as determined by phenotypic data and fluorescence in situ hybridisation (FISH) using probes specific for the only described PAO to date, Candidatus Accumulibacter phosphatis. DNA extraction methods were optimised and two fosmid libraries were constructed which contained 93 million base pairs of metagenomic data. Initial screening of the library for 16S rRNA genes revealed fosmids originating from a range of non-pure-cultured wastewater bacteria. The metagenomic libraries constructed will provide the ability to link phylogenetic and metabolic data for bacteria involved in nutrient removal from wastewater. Keywords DNA extraction; EBPR; metagenomic library; 16S rRNA gene.

The relationship between self-awareness of attentional status, behavioral performance and oscillatory brain rhythms

High-level cognitive factors, including self-awareness, are believed to play an important role in human visual perception. The principal aim of this study was to determine whether oscillatory brain rhythms play a role in the neural processes involved in self-monitoring attentional status. To do so we measured cortical activity using magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) while participants were asked to self-monitor their internal status, only initiating the presentation of a stimulus when they perceived their attentional focus to be maximal. We employed a hierarchical Bayesian method that uses fMRI results as soft-constrained spatial information to solve the MEG inverse problem, allowing us to estimate cortical currents in the order of millimeters and milliseconds. Our results show that, during self-monitoring of internal status, there was a sustained decrease in power within the 7-13 Hz (alpha) range in the rostral cingulate motor area (rCMA) on the human medial wall, beginning approximately 430 msec after the trial start (p < 0.05, FDR corrected). We also show that gamma-band power (41-47 Hz) within this area was positively correlated with task performance from 40-640 msec after the trial start (r = 0.71, p < 0.05). We conclude: (1) the rCMA is involved in processes governing self-monitoring of internal status; and (2) the qualitative differences between alpha and gamma activity are reflective of their different roles in self-monitoring internal states. We suggest that alpha suppression may reflect a strengthening of top-down interareal connections, while a positive correlation between gamma activity and task performance indicates that gamma may play an important role in guiding visuomotor behavior. © 2013 Yamagishi et al.

A comparative assessment of performance and productivity of health centres in Seychelles

Purpose - The purpose of this paper is to measure the technical and scale efficiency of health centres; to evaluate changes in productivity; and to highlight possible policy implications of the results for policy makers. Design/methodology/approach - Data envelopment analysis (DEA) is employed to assess the technical and scale efficiency, and productivity change over a four-year period among 17 public health centres. Findings - During the period of study, the results suggest that the public health centres in Seychelles have exhibited mean overall or technical efficiency of above 93 per cent. It was also found that the overall productivity increased by 2.4 per cent over 2001-2004. Research limitations/implications - Further research can be undertaken to gather data on the prices of the various inputs to facilitate an estimation of the allocative efficiency of clinics. If such an exercise were to be undertaken, researchers may also consider collecting data on quantities and prices of paramedical, administrative and support staff to ensure that the analysis is more comprehensive than the study reported in this paper. Institutionalization of efficiency monitoring would help to enhance further the already good health sector stewardship and governance. Originality/value - This paper provides new empirical evidence on a four-year trend in the efficiency and productivity of health centres in Seychelles. © Emerald Group Publishing Limited.

A study of performance and regulation in telecommunications in the European Union

This thesis looks at two issues. Firstly, statistical work was undertaken examining profit margins, labour productivity and total factor productivity in telecommunications in ten member states of the EU over a 21-year period (not all member states of the EU could be included due to data inadequacy). Also, three non-members, namely Switzerland, Japan and US, were included for comparison. This research was to provide an understanding of how telecoms in the European Union (EU) have developed. There are two propositions in this part of the thesis: (i) privatisation and market liberalisation improve performance; (ii) countries that liberalised their telecoms sectors first show a better productivity growth than countries that liberalised later. In sum, a mixed picture is revealed. Some countries performed better than others over time, but there is no apparent relationship between productivity performance and the two propositions. Some of the results from this part of the thesis were published in Dabler et al. (2002). Secondly, the remainder of the tests the proposition that the telecoms directives of the European Commission created harmonised regulatory systems in the member states of the EU. By undertaking explanatory research, this thesis not only seeks to establish whether harmonisation has been achieved, but also tries to find an explanation as to why this is so. To accomplish this, as a first stage to questionnaire survey was administered to the fifteen telecoms regulators in the EU. The purpose of the survey was to provide knowledge of methods, rationales and approaches adopted by the regulatory offices across the EU. This allowed for the decision as to whether harmonisation in telecoms regulation has been achieved. Stemming from the results of the questionnaire analysis, follow-up case studies with four telecoms regulators were undertaken, in a second stage of this research. The objective of these case studies was to take into account the country-specific circumstances of telecoms regulation in the EU. To undertake the case studies, several sources of evidence were combined. More specifically, the annual Implementation Reports of the European Commission were reviewed, alongside the findings from the questionnaire. Then, interviews with senior members of staff in the four regulatory authorities were conducted. Finally, the evidence from the questionnaire survey and from the case studies was corroborated to provide an explanation as to why telecoms regulation in the EU has reached or has not reached a state of harmonisation. In addition to testing whether harmonisation has been achieved and why, this research has found evidence of different approaches to control over telecoms regulators and to market intervention administered by telecoms regulators within the EU. Regarding regulatory control, it was found that some member states have adopted mainly a proceduralist model, some have implemented more of a substantive model, and others have adopted a mix between both. Some findings from the second stage of the research were published in Dabler and Parker (2004). Similarly, regarding market intervention by regulatory authorities, different member states treat market intervention differently, namely according to market-driven or non-market-driven models, or a mix between both approaches.

Real options and multinational investments : an empirical study of risk, performance and organisational awareness

DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY AND INFORMATION SERVICES WITH PRIOR ARRANGEMENT This thesis is a cross-disciplinary study of the empirical impact of real options theory in the fields of decision sciences and performance management. Borrowing from the economics, strategy and operations research literature, the research examines the risk and performance implications of real options in firms’ strategic investments and multinational operations. An emphasis is placed on the flexibility potential and competitive advantage of multinational corporations to explore the extent to which real options analysis can be classified as best practice in management research. Using a combination of qualitative and quantitative techniques the evidence suggests that, if real options are explored and exploited appropriately, real options management can result in superior performance for multinational companies. The qualitative findings give an overview of the practical advantages and disadvantages of real options and the statistical results reveal that firms which have developed a high awareness of their real options are, as predicted by the theory, able to reduce their downside risk and increase profits through flexibility, organisational slack and multinationality. Although real options awareness does not systematically guarantee higher returns from operations, supplementary findings indicate that firms with evidence of significant investments in the acquisition of real options knowledge tend to outperform competitors which are unaware of their real options. There are three contributions of this research. First, it extends the real options and capacity planning literature to path-dependent contingent-claims analysis to underline the benefits of average type options in capacity allocation. Second, it is thought to be the first to explicitly examine the performance effects of real options on a sample of firms which have developed partial capabilities in real options analysis suggesting that real options diffusion can be key to value creation. Third, it builds a new decision-aiding framework to facilitate the use of real options in projects appraisal and strategic planning.