Dissertations / Theses on the topic 'Software engineering not elsewhere classified'
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1
Soltani, Hamidreza. "Development and application of real-time and interactive software for complex system." Thesis, University of Central Lancashire, 2016. http://clok.uclan.ac.uk/20443/.
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Soft materials have attracted considerable interest in recent years for predicting the characteristics of phase separation and self-assembly in nanoscale structures. A popular method for demonstrating and simulating the dynamic behaviour of particles (e.g. particle tracking) and to consider effects of simulation parameters is cell dynamic simulation (CDS). This is a cellular computerisation technique that can be used to investigate different aspects of morphological topographies of soft material systems. The acquisition of quantitative data from particles is a critical requirement in order to obtain a better understanding and of characterising their dynamic behaviour. To achieve this objective particle tracking methods considering quantitative data and focusing on different properties and components of particles is essential. Despite the availability of various types of particle tracking used in experimental work, there is no method available to consider uniform computational data. In order to achieve accurate and efficient computational results for cell dynamic simulation method and particle tracking, two factors are essential: computing/calculating time-scale and simulation system size. Consequently, finding available computing algorithms and resources such as sequential algorithm for implementing a complex technique and achieving precise results is critical and rather expensive. Therefore, it is highly desirable to consider a parallel algorithm and programming model to solve time-consuming and massive computational processing issues. Hence, the gaps between the experimental and computational works and solving time consuming for expensive computational calculations need to be filled in order to investigate a uniform computational technique for particle tracking and significant enhancements in speed and execution times. The work presented in this thesis details a new particle tracking method for integrating diblock copolymers in the form of spheres with a shear flow and a novel designed GPU-based parallel acceleration approach to cell dynamic simulation (CDS). In addition, the evaluation of parallel models and architectures (CPUs and GPUs) utilising the mixtures of application program interface, OpenMP and programming model, CUDA were developed. Finally, this study presents the performance enhancements achieved with GPU-CUDA of approximately ~2 times faster than multi-threading implementation and 13~14 times quicker than optimised sequential processing for the CDS computations/workloads respectively.
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Timperley, Matthew. "The integration of explanation-based learning and fuzzy control in the context of software assurance as applied to modular avionics." Thesis, University of Central Lancashire, 2015. http://clok.uclan.ac.uk/16726/.
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A Modular Power Management System (MPMS) is an energy management system intended for highly modular applications, able to adapt to changing hardware intelligently. There is a dearth in the literature on Integrated Modular Avionics (IMA), which has previously not addressed the implications for software operating within this architecture. Namely, the adaptation of control laws to changing hardware. This work proposes some approaches to address this issue. Control laws may require adaptation to overcome hardware degradation, or system upgrades. There is also a growing interest in the ability to change hardware configurations of UASs (Unmanned Aerial Systems) between missions, to better fit the characteristics of each one. Hardware changes in the aviation industry come with an additional caveat: in order for a software system to be used in aviation it must be certified as part of a platform. This certification process has no clear guidelines for adaptive systems. Adapting to a changing platform, as well as addressing the necessary certification effort, motivated the development of the MPMS. The aim of the work is twofold. Firstly, to modify existing control strategies for new hardware. This is achieved with generalisation and transfer earning. Secondly, to reduce the workload involved with maintaining a safety argument for an adaptive controller. Three areas of work are used to demonstrate the satisfaction of this aim. Explanation-Based Learning (EBL) is proposed for the derivation of new control laws. The EBL domain theory embodies general control strategies, which are specialised to form fuzzy rules. A method for translating explanation structures into fuzzy rules is presented. The generation of specific rules, from a general control strategy, is one way to adapt to controlling a modular platform. A fuzzy controller executes the rules derived by EBL. This maintains fast rule execution as well as the separation of strategy and application. The ability of EBL to generate rules which are useful when executed by a fuzzy controller is demonstrated by an experiment. A domain theory is given to control throttle output, which is used to generate fuzzy rules. These rules have a positive impact on energy consumption in simulated flight. EBL is proposed, for rule derivation, because it focuses on generalisation. Generalisations can apply knowledge from one situation, or hardware, to another. This can be preferable to re-derivation of similar control laws. Furthermore, EBL can be augmented to include analogical reasoning when reaching an impasse. An algorithm which integrates analogy into EBL has been developed as part of this work. The inclusion of analogical reasoning facilitates transfer learning, which furthers the flexibility of the MPMS in adapting to new hardware. The adaptive capability of the MPMS is demonstrated by application to multiple simulated platforms. EBL produces explanation structures. Augmenting these explanation structures with a safetyspecific domain theory can produce skeletal safety cases. A technique to achieve this has been developed. Example structures are generated for previously derived fuzzy rules. Generating safety cases from explanation structures can form the basis for an adaptive safety argument.
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Kolbl, Josef Karl. "Low-noise frequency synthesis and picosecond timing for satellite laser ranging systems." Thesis, University of Central Lancashire, 2001. http://clok.uclan.ac.uk/20201/.
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The main aims of the research are to develop various high-speed hardware circuits based on the latest electronic devices and integrated circuit technologies to provide time measurement with one picosecond accuracy, thereby enabling the development of a satellite laser ranging (SLR) system with submillimeter precision. Different types of oscillators and frequency multipliers have been developed (RF and microwave) in order to provide a synchronous and low phase noise clock signal to the SLR timing system, which is phase-locked to the Universal Time Clock (UTC). A technique to quantify phase noise in signal sources is presented and verified. The development of the ranging system encompasses the analog timing verniers, the digital timing system, acquisition and processing of the ranging data, and the controlling of the peripherals, like the laser. The mixed analog/digital timing system architecture provides a time interval determination of two events with picosecond accuracy. Optical calibration techniques and an electronic timing calibration technique were developed to provide calibration of the timing system down to one picosecond accuracy and femtoseconds of resolution, traceable to the International Standard (speed of light, metric standard). The work done has led to several electronic modules for measuring precisely laser runtimes to artificial satellites and to the Moon which are now in successful and permanent operation in five SLR stations around Tokyo, one SLR station in Australia, and one SLR station in Germany. Furthermore, the work has produced three papers and two patents and won the First Prize of Innovation Awards from Deggendorf Government. The research and development work pushed the picosecond timing technology to an extent where the SLR stations in Australia, Tokyo and Germany now have a significant improvement in their ranging data accuracy in comparison to their previous timing equipment, thereby achieving more precise environmental monitoring.
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Macwhannell, Robert. "An investigation of Organisational Carbon Accounting (OCA) practices in the defence sector to determine how these can best support low carbon technology innovation." Thesis, University of Central Lancashire, 2018. http://clok.uclan.ac.uk/23077/.
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‘Climate change’ and ‘defence’ are becoming closely associated topics, particularly in relation to the potential that the defence sector has to support the development of low carbon technologies. This exploratory research applies an inductive approach and a strongly archival strategy in order to investigate how Organisational Carbon Accounting (OCA) practices in the defence sector can best support low carbon technology innovation. It takes an interdisciplinary approach to the literature, drawing on the fields of Carbon Accounting, Defence Industrial Policy, and Innovation Studies. It finds that there some difficulties allocating emissions to organisations in existing OCAs, which are particularly marked in the defence sector due to close working relationships between organisations. These allocations can result in abstract OCAs that do not always reflect the underlying activities causing emissions to be produced. In contrast, ‘Project Level’ Carbon Accounts focused on large-scale collaborative programmes can better account for the emissions of the defence sector in an understandable way that engages new and relevant actors to defence-energy debates. These accounts are therefore more likely than existing OCA practices to support low carbon technology development across innovation networks. A positive selection environment for low carbon technologies can be promoted if these ‘Project-Level’ Carbon Accounts are presented within an appropriate strategic framework, and this research describes the relevance of the defence sector concepts of ‘resilience’ and ‘endurance’ and the related metric of the Fully Burdened Cost of Energy (FBCE). The findings emphasise the value of sector-level analyses of OCA practices, which are not represented in the literature at present. The sector-level perspective can help identify relevant methods from the wider Carbon Accounting field that can improve existing organisational approaches. More importantly, it can help researchers engage with the fundamental question of what Carbon Accounting is for, by analysing how the OCA practices within a specific sector support or inhibit its most effective contribution to climate change mitigation.
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Thakore, Renuka. "A strategic engagement model for delivering energy efficiency initiatives in the English housing sector." Thesis, University of Central Lancashire, 2016. http://clok.uclan.ac.uk/18647/.
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Housing sectors have particular significance and impact on resource use, deployment and sustainability. Given this, they are inextricably enmeshed in a raft of conjoined issues, ranging from energy, production and consumption, through to effective governance structures and leveraged sustainable transformations. However, the real challenges facing the Housing sectors rest with the supportive societal structures which underpin the operationalisation of these issues. This includes such factors as consultation and engagement, and the identification of critical drivers and proven solutions – which are tangible barriers for sustainable transformations (particularly in the English housing system). This research presents a conceptual model – STRIDES (Strategic Tri-level Relational Interventions for Delivering Energy efficiency and Sustainability), which purposefully addresses the aforementioned barriers, and critically challenges thinking and engagement. STRIDES explicitly captures 5-INs, which embodies interrelated essential conditions needed for successful transformation. This conceptual model was developed using a mixed-method approach, engaging constructivism/interpretivism to guide the development and augmentation of this (to ensure maximum relevance and impact). The English housing system was used as the primary lens – which helped both shape and inform the research methodological approach. STRIDES was developed through: an online survey questionnaire (for systems-knowledge); Delphi questionnaires (for target-knowledge); and focus group discussions (for transformative-knowledge). The theoretical constructs and methods revealed exclusive hidden dialogue of composite correlated multi-perspective stakeholders, which highlighted tri-level influences on interdependent system-components for effective governance of sustainable transformations. Recognising and prioritising relationally responsive emerging strategies arising from STRIDES help stakeholders appreciate subtle nuances and forces across and beyond contexts. This helps positioning, especially to shape/tailor strategic interventions to deliver meaningful objectives of these sustainable transformations.
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Prince, Mark. "Smart microsystems for cell manipulations." Thesis, Aston University, 2006. http://publications.aston.ac.uk/12241/.
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This thesis documents the design, manufacture and testing of a passive and non-invasive micro-scale planar particle-from-fluid filter for segregating cell types from a homogeneous suspension. The microfluidics system can be used to separate spermatogenic cells from testis biopsy samples, providing a mechanism for filtrate retrieval for assisted reproduction therapy. The system can also be used for point-of-service diagnostics applications for hospitals, lab-on-a-chip pre-processing and field applications such as clinical testing in the third world. Various design concepts are developed and manufactured, and are assessed based on etched structure morphology, robustness to variations in the manufacturing process, and design impacts on fluid flow and particle separation characteristics. Segregation was measured using image processing algorithms that demonstrate efficiency is more than 55% for 1 µl volumes at populations exceeding 1 x 107. the technique supports a significant reduction in time over conventional processing, in the separation and identification of particle groups, offering a potential reduction in the associated cost of the targeted procedure. The thesis has developed a model of quasi-steady wetting flow within the micro channel and identifies the forces across the system during post-wetting equalisation. The model and its underlying assumptions are validated empirically in microfabricated test structures through a novel Micro-Particle Image Velocimetry technique. The prototype devices do not require ancillary equipment nor additional filtration media, and therefore offer fewer opportunities for sample contamination over conventional processing methods. The devices are disposable with minimal reagent volumes and process waste. Optimal processing parameters and production methods are identified with any improvements that could be made to enhance their performance in a number of identified potential applications.
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Bansal, Dheeraj. "An advanced real-time predictive maintenance framework for large scale machine systems." Thesis, Aston University, 2005. http://publications.aston.ac.uk/12235/.
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This thesis introduces and develops a novel real-time predictive maintenance system to estimate the machine system parameters using the motion current signature. A crucial concept underpinning this project is that the motion current signature contains information relating to the machine system parameters and that this information can be extracted using nonlinear mapping techniques, such as neural networks. Towards this end, a proof of concept procedure is performed, which substantiates this concept. A simulation model, TuneLearn, is developed to simulate the large amount of training data required by the neural network approach. Statistical validation and verification of the model is performed to ascertain confidence in the simulated motion current signature. Validation experiment concludes that, although, the simulation model generates a good macro-dynamical mapping of the motion current signature, it fails to accurately map the micro-dynamical structure due to the lack of knowledge regarding performance of higher order and nonlinear factors, such as backlash and compliance. Failure of the simulation model to determine the micro-dynamical structure suggests the presence of nonlinearity in the motion current signature. This motivated us to perform surrogate data testing for nonlinearity in the motion current signature. Results confirm the presence of nonlinearity in the motion current signature, thereby, motivating the use of nonlinear techniques for further analysis. Outcomes of the experiment show that nonlinear noise reduction combined with the linear reverse algorithm offers precise machine system parameter estimation using the motion current signature for the implementation of the real-time predictive maintenance system. Finally, a linear reverse algorithm, BJEST, is developed and applied to the motion current signature to estimate the machine system parameters.
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Slack, Paul Stephen. "A novel detection method for determining a surgeon's fatigue and hand tremor." Thesis, Aston University, 2007. http://publications.aston.ac.uk/12238/.
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The thesis presents new methodology and algorithms that can be used to analyse and measure the hand tremor and fatigue of surgeons while performing surgery. This will assist them in deriving useful information about their fatigue levels, and make them aware of the changes in their tool point accuracies. This thesis proposes that muscular changes of surgeons, which occur through a day of operating, can be monitored using Electromyography (EMG) signals. The multi-channel EMG signals are measured at different muscles in the upper arm of surgeons. The dependence of EMG signals has been examined to test the hypothesis that EMG signals are coupled with and dependent on each other. The results demonstrated that EMG signals collected from different channels while mimicking an operating posture are independent. Consequently, single channel fatigue analysis has been performed. In measuring hand tremor, a new method for determining the maximum tremor amplitude using Principal Component Analysis (PCA) and a new technique to detrend acceleration signals using Empirical Mode Decomposition algorithm were introduced. This tremor determination method is more representative for surgeons and it is suggested as an alternative fatigue measure. This was combined with the complexity analysis method, and applied to surgically captured data to determine if operating has an effect on a surgeon’s fatigue and tremor levels. It was found that surgical tremor and fatigue are developed throughout a day of operating and that this could be determined based solely on their initial values. Finally, several Nonlinear AutoRegressive with eXogenous inputs (NARX) neural networks were evaluated. The results suggest that it is possible to monitor surgeon tremor variations during surgery from their EMG fatigue measurements.
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Shalan, Mohamad A. "The integration of multi-source data to improve the classification of remotely sensed images." Thesis, Aston University, 2005. http://publications.aston.ac.uk/12246/.
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The number of remote sensing platforms and sensors rises almost every year, yet much work on the interpretation of land cover is still carried out using either single images or images from the same source taken at different dates. Two questions could be asked of this proliferation of images: can the information contained in different scenes be used to improve the classification accuracy and, what is the best way to combine the different imagery? Two of these multiple image sources are MODIS on the Terra platform and ETM+ on board Landsat7, which are suitably complementary. Daily MODIS images with 36 spectral bands in 250-1000 m spatial resolution and seven spectral bands of ETM+ with 30m and 16 days spatial and temporal resolution respectively are available. In the UK, cloud cover may mean that only a few ETM+ scenes may be available for any particular year and these may not be at the time of year of most interest. The MODIS data may provide information on land cover over the growing season, such as harvest dates, that is not present in the ETM+ data. Therefore, the primary objective of this work is to develop a methodology for the integration of medium spatial resolution Landsat ETM+ image, with multi-temporal, multi-spectral, low-resolution MODIS \Terra images, with the aim of improving the classification of agricultural land. Additionally other data may also be incorporated such as field boundaries from existing maps. When classifying agricultural land cover of the type seen in the UK, where crops are largely sown in homogenous fields with clear and often mapped boundaries, the classification is greatly improved using the mapped polygons and utilising the classification of the polygon as a whole as an apriori probability in classifying each individual pixel using a Bayesian approach. When dealing with multiple images from different platforms and dates it is highly unlikely that the pixels will be exactly co-registered and these pixels will contain a mixture of different real world land covers. Similarly the different atmospheric conditions prevailing during the different days will mean that the same emission from the ground will give rise to different sensor reception. Therefore, a method is presented with a model of the instantaneous field of view and atmospheric effects to enable different remote sensed data sources to be integrated.
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Kamnis, Spyros. "Development of multiphase and multiscale mathematical models for thermal spray process." Thesis, Aston University, 2007. http://publications.aston.ac.uk/12243/.
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High velocity oxyfuel (HVOF) thermal spraying is one of the most significant developments in the thermal spray industry since the development of the original plasma spray technique. The first investigation deals with the combustion and discrete particle models within the general purpose commercial CFD code FLUENT to solve the combustion of kerosene and couple the motion of fuel droplets with the gas flow dynamics in a Lagrangian fashion. The effects of liquid fuel droplets on the thermodynamics of the combusting gas flow are examined thoroughly showing that combustion process of kerosene is independent on the initial fuel droplet sizes. The second analysis copes with the full water cooling numerical model, which can assist on thermal performance optimisation or to determine the best method for heat removal without the cost of building physical prototypes. The numerical results indicate that the water flow rate and direction has noticeable influence on the cooling efficiency but no noticeable effect on the gas flow dynamics within the thermal spraying gun. The third investigation deals with the development and implementation of discrete phase particle models. The results indicate that most powder particles are not melted upon hitting the substrate to be coated. The oxidation model confirms that HVOF guns can produce metallic coating with low oxidation within the typical standing-off distance about 30cm.
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Bambury, M. C. "Development of a sediment yield model for South East Ghana in the regions around Lake Volta." Thesis, Aston University, 2007. http://publications.aston.ac.uk/12245/.
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In Ghana, a country with an expanding population and high potential for economic growth, agriculture is an important resource; however, most of the crop production is restricted to low technology shifting cultivation agriculture. The high intensity seasonal rainfall coincides with the early growing period of many of the crops meaning that plots are very susceptible to erosion, especially on steep sided valleys in the region south of Lake Volta. This research investigated the processes of soil erosion by rainfall with the aim of producing a sediment yield model for a small semi-agricultural catchment in rural Ghana. Various types of modelling techniques were considered to discover those most applicable to the sub-tropical environment of Southern Ghana. Once an appropriate model had been developed and calibrated, the aim was to look at how to enable the scaling up of the model using sub-catchments to calculate sedimentation rates of Lake Volta. An experimental catchment was located in Ghana, south west of Lake Volta, where data on rainstorms and the associated streamflow, sediment loads and soil data (moisture content, classification and particle size distribution) was collected to calibrate the model. Additional data was obtained from the Soil Research Institute in Ghana to explore calibration of the Universal Soil Loss Equation (USLE, Wischmeier and Smith, 1978) for Ghanaian soils and environment. It was shown that the USLE could be successfully converted to provide meaningful soil loss estimates in the Ghanaian environment. However, due to experimental difficulties, the proposed theory and methodology of the sediment yield model could only be tested in principle. Future work may include validation of the model and subsequent scaling up to estimate sedimentation rates in Lake Volta.
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Tam, B. K. Y. "A novel actuated digit with tactile feedback for clinical applications." Thesis, Aston University, 2006. http://publications.aston.ac.uk/12247/.
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This thesis describes the work carried out on the development of a novel digit actuator system with tactile perception feedback to a user and demonstrated as a master-slave system. For the tactile surface of the digit, contrasting sensor elements of resistive strain gauges and optical fibre Bragg grating sensors were evaluated. A distributive tactile sensing system consisting of optimised neural networking schemes was developed, resulting in taxonomy of artificial touch. The device is suitable for use in minimal invasive surgical (MIS) procedures as a steerable tip and a digit constructed wholly from polymers makes it suitable for use in Magnetic Resonance Imaging (MRI) environments enabling active monitoring of the patient during a procedure. To provide a realistic template of the work the research responded to the needs of two contrasting procedures: palpation of the prostate and endotracheal intubation in anaesthesia where the application of touch sense can significantly assist navigation. The performance of the approach was demonstrated with an experimental digit constructed for use in the laboratory in phantom trials. The phantom unit was developed to resemble facets of the clinical applications and digit system is able to evaluate reactive force distributions acting over the surface of the digit as well as different descriptions of contact and motion relative to the surface of the lumen. Completing control of the digit is via an instrumented glove, such that the digit actuates in sympathy with finger gesture and tactile information feedback is achieved by a combination of the tactile and visual means.
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Zhang, Yumin. "Virtual manufacturing - a study of some important issues relating to the transformation of traditional manufacturing organisations." Thesis, Aston University, 2006. http://publications.aston.ac.uk/12237/.
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This thesis starts with a literature review, outlining the major issues identified in the literature concerning virtual manufacturing enterprise (VME) transformation. Then it details the research methodology used – a systematic approach for empirical research. next, based on the conceptual framework proposed, this thesis builds three modules to form a reference model, with the purpose of clarifying the important issues relevant to transforming a traditional manufacturing company into a VME. The first module proposes a mechanism of VME transformation – operating along the VME metabolism. The second module builds a management function within a VME to ensure a proper operation of the mechanism. This function helps identify six areas as closely related to VME transformation: lean manufacturing; competency protection; internal operation performance measurement; alliance performance measurement; knowledge management; alliance decision making. The third module continues and proposes an alliance performance measurement system which includes 14 categories of performance indicators. An analysis template for alliance decision making is also proposed and integrated into the first module. To validate these three modules, 7 manufacturing organisations (5 in China and 2 in the UK) were investigated, and these field case studies are analysed in this thesis. The evidence found in these organisations, together with the evidence collected from the literature, including both researcher views and literature case studies, provide support for triangulation evidence. In addition, this thesis identifies the strength and weakness patterns of the manufacturing companies within the theoretical niche of this research, and clarifies the relationships among some major research areas from the perspective of virtual manufacturing. Finally, the research findings are summarised, as well as their theoretical and practical implications. Research limitations and recommendations for future work conclude this thesis.
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Lamont, D. R. "Decompression illness and its regulation in contemporary UK tunnelling : an engineering perspective." Thesis, Aston University, 2006. http://publications.aston.ac.uk/12242/.
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This thesis records the findings of a retrospective study of decompression illness (DCI) in the UK compressed air tunnelling industry since the mid-1980s. The thesis describes how the study arose, its scope and objectives, along with an overview of tunnelling and shaft-sinking. The development of compressed air working techniques is reviewed along with a description of decompression practice and DCI, and an outline of relevant legislation and guidance. The acquisition and manipulation of data to form a number of databases and spreadsheets on which the analysis was performed is discussed. That analysis examined measures of DCI incidence and quantified that incidence using these measures. Also considered is the variation in tolerance and susceptibility to DCI in the workforce, and the phenomenon of acclimatisation. An examination of the extent to which men worked on multiple contracts and the variation in their susceptibility to DCI on these contracts is included. The main conclusions are that a number of measures of DCI incidence were identified, some more appropriate than others and that the incidence of DCI when so measured was high, disproportionately so in shift workers. No reasonably practicable restrictions on exposure were identified which would have allowed the retention of air-only decompression. Oxygen decompression looked promising but had yet to be used sufficiently extensively to generate enough data for analysis. Recommendations included one that an alternative technique for monitoring the effectiveness of decompression should be developed. The thesis ends with recommendations for further research.
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Tran, Tuan D. "Global optimisation of cold-formed steel sections." Thesis, Aston University, 2007. http://publications.aston.ac.uk/12239/.
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In this thesis, standard algorithms are used to carry out the optimisation of cold-formed steel purlins such as zed, channel and sigma sections, which are assumed to be simply supported and subjected to a gravity load. For zed, channel and sigma section, the local buckling, distortional buckling and lateral-torsional buckling are considered respectively herein. Currently, the local buckling is based on the BS 5950-5:1998 and EN 1993-1-3:2006. The distortional buckling is calculated by the direct strength method employing the elastic distortional buckling which is calculated by three available approaches such as Hancock (1995), Schafer and Pekoz (1998), Yu (2005). In the optimisation program, the lateral-torsional buckling based on BS 5950-5:1998, AISI and analytical model of Li (2004) are investigated. For the optimisation program, the programming codes are written for optimisation of channel, zed and sigma beam. The full study has been coded into a computer-based analysis program (MATLAB).
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Petra, Mohamad Iskandar. "Novel hardwired distributive tactile sensing system for medical applications." Thesis, Aston University, 2007. http://publications.aston.ac.uk/12240/.
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This thesis described the research carried out on the development of a novel hardwired tactile sensing system tailored for the application of a next generation of surgical robotic and clinical devices, namely a steerable endoscope with tactile feedback, and a surface plate for patient posture and balance. Two case studies are examined. The first is a one-dimensional sensor for the steerable endoscope retrieving shape and 'touch' information. The second is a two-dimensional surface which interprets the three-dimensional motion of a contacting moving load. This research can be used to retrieve information from a distributive tactile sensing surface of a different configuration, and can interpret dynamic and static disturbances. This novel approach to sensing has the potential to discriminate contact and palpation in minimal invasive surgery (MIS) tools, and posture and balance in patients. The hardwired technology uses an embedded system based on Field Programmable Gate Arrays (FPGA) as the platform to perform the sensory signal processing part in real time. High speed robust operation is an advantage from this system leading to versatile application involving dynamic real time interpretation as described in this research. In this research the sensory signal processing uses neural networks to derive information from input pattern from the contacting surface. Three neural network architectures namely single, multiple and cascaded were introduced in an attempt to find the optimum solution for discrimination of the contacting outputs. These architectures were modelled and implemented into the FPGA. With the recent introduction of modern digital design flows and synthesis tools that essentially take a high-level sensory processing behaviour specification for a design, fast prototyping of the neural network function can be achieved easily. This thesis outlines the challenge of the implementations and verifications of the performances.
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Chu, Xiao-ting. "Failure analysis of cold-formed steel sections." Thesis, Aston University, 2004. http://publications.aston.ac.uk/12234/.
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The purlin-sheeting system has been the subject of numerous theoretical and experimental investigations over the past 30 years, but the complexity of the problem has led to great difficulty in developing a sound and general model. The primary aim of the thesis is to investigate the failure behaviours of cold-formed zed and channel sections for use in purlin-sheeting systems. Both the energy method and finite strip method are used to develop an approach to investigate cold-formed zed and channel section beams with partial-lateral restraint from the metal sheeting when subjected to a uniformly distributed transverse load. The stress analysis of cold-formed zed and channel section beams with partially-lateral restraint from the metal sheeting when subjected to a uniformly distributed transverse load is investigated firstly by using the analytical model based on the energy method in which the restraint actions of the sheeting are modelled by using two springs representing the translational and rotational restraints. The numerical results have showed that the two springs have significantly different influences on the stresses of the beams. The influence of the two springs has also been found to depend on the anti-sag bar and the position of the loading line. A novel method is presented for analysing the elastic local buckling behaviour of cold-formed zed and channel section beams with partial-lateral restraint from metal sheeting when subjected to a uniformly distributed transverse load, which is carried out by inputting the cross sectional stresses with the largest compressive stress into the finite strip analysis. By using the presented novel method, individual influences of warning stress, partially lateral restraints from the sheeting and the dimensions of the cross section and position of the loading line on the buckling behaviour are investigated.
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Chileshe, C. M. "A converter compensator for power factor control in 3-phase induction machines." Thesis, Aston University, 1996. http://publications.aston.ac.uk/12244/.
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The advent of the harmonic neutralised shunt Converter Compensator as a practical means of reactive power compensation in power transmission systems has cleared ground for wider application of this type of equipment. An experimental 24-pulse voltage sourced convector has been successfully applied in controlling the terminal power factor of a 1.5kW, 240V three phase cage rotor induction motor, whose winding has been used in place of the usual phase shifting transformers. To achieve this, modifications have been made to the conventional stator winding of the induction machine. These include an unconventional phase spread and facilitation of compensator connections to selected tapping points between stator coils to give a three phase winding with a twelve phase connection to the twenty four pulse converter. Theoretical and experimental assessments of the impact of these modifications and attachment of the compensator have shown that there is a slight reduction in the torque developed at a given slip and in the combined system efficiency. There is also an increase in the noise level, also a consequence of the harmonics. The stator leakage inductance gave inadequate coupling reactance between the converter and the effective voltage source, necessitating the use of external inductors in each of the twelve phases. The terminal power factor is fully controllable when the induction machine is used either as a motor or as a generator.
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(9189275), Xiang Zhou. "Numerical Simulation of Dendrites Growth in Continuous Casting by Using Open Source Software." Thesis, 2020.
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Cracking in continuous casting has always been one of the main problems of steel mills. Many cracks that occur during solidification are difficult to observe from outside the industrial mold. In order to better understand the formation of this defect, compared with the large-scale simulation used in the entire industrial process, microsimulation is also essential. A comprehensive study of using phase field method to simulate microstructure evolution has been conducted. A variety of two-dimensional models based on phase-filed method has been developed in order to simulate dendrites growth in continuous casting process. The basic concepts of phase-field method are presented. Among those models, Kobayashi model was first introduced to describe the morphology of pure material solidification, in this article, which are pure water and pure iron. In order to get closer to the actual situation of continuous casting, a multi-component model was introduced to solve the problem. To go a step further, by introducing a series of temperature parameters and modifications to a series of terms, the binary alloy directional solidification model was used to simulate the process of dendrite growth in continuous casting. Furthermore, the detailed derivation of the binary alloy solidification model and how to apply the model in open source software will also be introduced in this article. The effects of physical parameters such as anisotropic strength, temperature gradient and cooling rate on the growth and evolution of the dendrite interface were quantitatively analyzed. Finally, potential improvement of this model, optimization to primary cooling section in continuous casting process and various applications of the simulation were discussed.
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(10184063), Younghoon Kim. "Approximate Computing: From Circuits to Software." Thesis, 2021.
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Many modern workloads such as multimedia, recognition, mining, search, vision, etc. possess the characteristic of intrinsic application resilience: The ability to produce acceptable-quality outputs despite their underlying computations being performed in an approximate manner. Approximate computing has emerged as a paradigm that exploits intrinsic application resilience to design systems that produce outputs of acceptable quality with significant performance/energy improvement. The research community has proposed a range of approximate computing techniques spanning across circuits, architecture, and software over the last decade. Nevertheless, approximate computing is yet to be incorporated into mainstream HW/SW design processes largely due to the deviation from the conventional design flow and the lack of runtime approximation controllability by the user.
The primary objective of this thesis is to provide approximate computing techniques across different layers of abstraction that possess the two following characteristics: (i) They can be applied with minimal change to the conventional design flow, and (ii) the approximation is controllable at runtime by the user with minimal overhead. To this end, this thesis proposes three novel approximate computing techniques: Clock overgating which targets HW design at the Register Transfer Level (RTL), value similarity extensions which enhance general-purpose processors with a set of microarchitectural and ISA extensions, and data subsetting which targets SW executing for commodity platforms.
The thesis first explores clock overgating, which extends the concept of clock gating: A conventional low-power technique that turns off the clock to a Flip-Flop (FF) when the value remains unchanged. In contrast to traditional clock gating, in clock overgating the clock signals to selected FFs in the circuit are gated even when the circuit functionality is sensitive to their state. This saves additional power in the clock tree, the gated FFs and in their downstream logic, while a quality loss occurs if the erroneous FF states propagate to the circuit outputs. This thesis develops a systematic methodology to identify an energy-efficient clock overgating configuration for any given circuit and quality constraint. Towards this end, three key strategies for efficiently pruning the large space of possible overgating configurations are proposed: Significance-based overgating, grouping FFs into overgating islands, and utilizing internal signals of the circuit as triggers for overgating. Across a suite of 6 machine learning accelerators, energy benefits of 1.36X on average are achieved at the cost of a very small (<0.5%) loss in classification accuracy.
The thesis also explores value similarity extensions, a set of lightweight micro-architectural and ISA extensions for general-purpose processors that provide performance improvements for computations on data structures with value similarity. The key idea is that programs often contain repeated instructions that are performed on very similar inputs (e.g., neighboring pixels within a homogeneous region of an image). In such cases, it may be possible to skip an instruction that operates on data similar to a previously executed instruction, and approximate the skipped instruction's result with the saved result of the previous one. The thesis provides three key strategies for realizing this approach: Identifying potentially skippable instructions from user annotations in SW, obtaining similarity information for future load values from the data cache line currently being accessed, and a mechanism for saving & reusing results of potentially skippable instructions. As a further optimization, the thesis proposes to replace multiple loop iterations that produce similar results with a specialized instruction sequence. The proposed extensions are modeled on the gem5 architectural simulator, achieving speedup of 1.81X on average across 6 machine-learning benchmarks running on a microcontroller-class in-order processor.
Finally, the thesis explores a data-centric approach to approximate computing called data subsetting that shifts the focus of approximation from computations to data. The key idea is to restrict the application's data accesses to a subset of its elements so that the overall memory footprint becomes smaller. Constraining the accesses to lie within a smaller memory footprint renders the memory accesses more cache-friendly, thereby improving performance. This thesis presents a C++ data structure template called SubsettableTensor, which embodies mechanisms to define an accessible subset of data and redirect accesses away from non-subset elements, for realizing data subsetting in SW. The proposed concept is evaluated on parallel SW implementations of 7 machine learning applications on a 48-core AMD Opteron server. Experimental results indicate that 1.33X-4.44X performance improvement can be achieved within a <0.5% loss in classification accuracy.
In summary, the proposed approximation techniques have shown significant efficiency improvements for various machine learning applications in circuits, architecture and SW, underscoring their promise as designer-friendly approaches to approximate computing.
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(9790478), Sandra Dalton. "Development and evaluation of a software prototype for hydrotherapy screening questionnaires and exercise routines." Thesis, 2007. https://figshare.com/articles/thesis/Development_and_evaluation_of_a_software_prototype_for_hydrotherapy_screening_questionnaires_and_exercise_routines/13429553.
Full textAbstract:
"This research investigated factors affecting the development and adoption of innovative work practices by exercise rehabilitation providers working in hydrotherapy pools. Using models from the fields of software engineering and behavioural science, this thesis describes how the author developed and then evaluated a software prototype to create individual exercise regimes and manage client information. The prototype was written by the researcher using Microsoft Access and Microsoft Visual Basic and included 563 exercise pictures drawn by the author as Microsoft Bitmap Images. This prototype was then evaluated for its S2quality and useS3 by nine professional staff at a large aquatic physiotherapy clinic in metropolitan Australia. The evaluation was conducted at the end of a one month software trial with participants completing two questionnaires and attending one of two focus group interviews. The questionnaires were a User Profile Questionnaire and a Software Usability Measurement Inventory (SUMI). The major findings from the evaluation were that the prototype was too complex compared to the participants current methods of practice and it provided insufficient advantages to justify its adoption. This finding was reflected by the poor to below average results from the SUMI questionnaire and was discussed by participants during focus group interviews. Furthermore, the User Profile Questionnaire and the interviews suggest that hydrotherapy instructors are unlikely to use or be aware of existing exercise software products for creating client routines. For the 30% of participants who had previously used exercise software, none chose to use such products for their hydrotherapy clients because of the limited number and range of aquatic exercises they offered. While the results suggested a strong resistance to the use of any exercise software by hydrotherapy instructors, the participants strongly encouraged future development of the prototype, with design changes to better match their needs. The consensus of opinion encouraged removal or separation of the pre-exercise screening questionnaires and a focus on creating exercise routines. The prototypes large library of water exercises was recognized as a valuable resource with numerous opportunities to redesign the system used to classify different types of exercise in the library for use by different types of water-based exercise instructors. Conclusions drawn of this research are presented in two parts. The first presents a SWOT analysis, summarizing the major recommendations from the software evaluation. This includes strategies for improving both the software prototype and the general acceptance of a new technology. The second offers advice to others with an interest in undertaking creative research as a postgraduate project, especially in a field of science. This advice includes strategies found to be fundamental to the planning and management of creative research projects such as this." -- abstract.
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Mastilovich, Nikola. "Automatisation of programming of a PLC code : a thesis presented in partial fulfilment of the requirements of the degree of Masters of Engineering in Mechatronics." 2010. http://hdl.handle.net/10179/1681.
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Appendix D, CD content can be found with print thesis held at Turitea library, Palmerston North. Content: Empty APCG program Empty RSLogix5000 l5k file Empty RSLogix5000 ACD file Real Life project - APCG program (only partial) Real Life project - RSLogix5000 l5k file (only partial) Real Life project - RSLogix5000 ACD file (only partial)A competitive edge is one of the requirements of a successful business. Tools, which increase an engineer s productivity and minimize cost, can be considered as a competitive edge. The objective of this thesis was to design, create, and implement Automatic PLC Code Generator (APCG) software. A secondary objective was to demonstrate that the use of the APCG software will lead to improved project efficiency and enhanced profit margin. To create the APCG software, the MS Excel and Visual Basic for Applications (VBA) programs were used as the platform. MS Excel sheets were used as a user interface, while VBA creates the PLC code from the information entered by the engineer. The PLC code, created by the APCG software, follows the PLC structure of the Realcold Milmech Pty. Ltd, as well as the research Automatic generation of PLC code beyond the nominal sequence written by Guttel et al [1]. The APCG software was used to design and create a PLC code for one of the projects undertaken by Realcold Milmech Pty. Ltd. By using APCG software, time to design, create, and test the PLC code was improved when compared to the budgeted time. In addition, the project's profit margin was increased. Based on the results of this thesis it is expected that the APCG software will be useful for programmers that tend to handle a variety of projects on a regular basis, where programming in a modular way is not appropriate.
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(8740677), Jeremy Sickmiller. "REAL TIME CONTROL OF MANUFACTURING UTILIZING A MANUFACTURING EXECUTION SYSTEM (MES)." Thesis, 2020.
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Manufacturing facilities need control for sustainability and longevity. If no control is provided for the manufacturing facility, then chaos can be unleashed causing much alarm. Therefore, it is essential to understand how control can be utilized to support the manufacturing facility and the corresponding manufacturing processes. This thesis will walk through a tool to help provide control and that tool is a Manufacturing Execution System (MES). Thisthesis will start with research to defineMESand its implications, then will work into the development of MES from the ground up. The design process willbe systematic and utilize the Collective System Design (CSD) approach with the aiding tool of the axiomatic decomposition map. Then examples will be given for the implementation and execution of the decomposition map as it relates to inventory and traceability. Finalwork will show the 7 FRs ofmanufacturing and how they are applicable to MES with given examples. Throughout the entire design and implementation, the initial hypothesis will be evaluated to determine if MES can provide the control requiredfor a robust manufacturing facility.
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(9847022), Qing Wu. "Optimisations of draft gear designs for heavy haul trains." Thesis, 2016. https://figshare.com/articles/thesis/Optimisations_of_draft_gear_designs_for_heavy_haul_trains/13443179.
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This thesis developed a parallel multiobjective optimisation methodology to enable fast optimisations of draft gear designs for heavy haul trains. Improvements were achieved in the development of deterministic white-box draft gear models to enable direct use of the results in product design. Draft gear model parameters such as spring stiffness, wedge angles, and preloads were used as optimisation variables. Two optimisation algorithms were used: Genetic Algorithm and Particle Swarm Optimisation. All draft gear designs in the optimisations were
constrained by impact tests to ensure the optimised designs also comply with current draft gear acceptance standards. Draft gear performance was assessed using whole-trip Longitudinal Train Dynamics (LTD) simulations and coupler fatigue damage calculations. Each simulation covered about 640 km of track and had about 10 hours of operational time. Three optimisation objectives were considered: minimal fatigue damage for wagon connection systems of loaded trains, minimal in-train (coupler) forces for loaded trains, and minimal longitudinal wagon
accelerations for empty trains.
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(9189365), Anthony A. Lowe. "The Theory of Applied Mind of Programming." Thesis, 2020.
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The Theory of Applied Mind of Programming (TAMP) provides a new model for describing how programmers think and learn. Historically, many students have struggled when learning to program. Programming as a discipline lives in logic and reason, but theory and science tell us that people do not always think rationally. TAMP builds upon the groundbreaking work of dual process theory and classical educational theorists (Piaget, Vygotsky, and Bruner) to rethink our assumptions about cognition and learning. Theory guides educators and researchers to improve their practice, not just their work but also their thinking. TAMP provides new theoretical constructs for describing the mental activities of programming, the challenges in learning to program, as well as a guidebook for creating and recognizing the value of theory.
This dissertation is highly nontraditional. It does not include a typical empirical study using a familiar research methodology to guide data collection and analysis. Instead, it leverages existing data, as accumulated over a half-century of computing education research and a century of research into cognition and learning. Since an applicable methodology of theory-building did not exist, this work also defines a new methodology for theory building. The methodology of this dissertation borrows notation from philosophy and methods from grounded theory to define a transparent and rigorous approach to creating applied theories. By revisiting past studies through the lens of new theoretical propositions, theorists can conceive, refine, and internally validate new constructs and propositions to revolutionize how we view technical education.
The takeaway from this dissertation is a set of new theoretical constructs and promising research and pedagogical approaches. TAMP proposes an applied model of Jerome Bruner's mental representations that describe the knowledge and cognitive processes of an experienced programmer. TAMP highlights implicit learning and the role of intuition in decision making across many aspects of programming. This work includes numerous examples of how to apply TAMP and its supporting theories in re-imagining teaching and research to offer alternative explanations for previously puzzling findings on student learning. TAMP may challenge conventional beliefs about applied reasoning and the extent of traditional pedagogy, but it also offers insights on how to promote creative problem-solving in students.
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Stuart, Gordon F. "Classified models for software engineering." Thesis, 1991. http://hdl.handle.net/1828/39.
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In this dissertation it is shown that abstract data types (ADTs) can be specified by the Classified Model (CM) specification language - a first-order Horn language with equality and sort "classification" assertations. It is shown how these sort assertations generalize the traditional syntactic signatures of ADT specifications, resulting in all of the specification capability of traditional equational specifications, but with the improved expressibility of the Horn-with-equality language and additional theorem proving applications such as program synthesis.
This work extends corresponding results from Many Sorted Algebra (MSA), Order Sorted Algebra (OSA) and Order Sorted Model (OSM) specification techniques by promoting their syntactic signatures to assertions in the Classified Model Specification language, yet retaining sorted quantification. It is shown how this solves MSA problems such as error values, polymorphism and subtypes in a way different from the OSA and OSM solutions. However, the CM technique retains the MSA and order sorted approach to parameterization. The CS generalization also suggests the use of CM specifications to axiomatize modules as a generalization of variables within Hoare Logic, with application to a restricted, but safe, use of procedures as state changing operations and functions as value returning operations of a module. CM proof theory and semantics are developed, including theorems for soundness, completeness and the existence of a free model.
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(10063480), Monil Vallabhbh Chheta. "DESIGN AND IMPLEMENTATION OF ENERGY USAGE MONITORING AND CONTROL SYSTEMS USING MODULAR IIOT FRAMEWORK." Thesis, 2021.
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This project aims to develop a cloud-based platform that integrates sensors with business intelligence for real-time energy management at the plant level. It provides facility managers, an energy management platform that allows them to monitor equipment and plant-level energy consumption remotely, receive a warning, identify energy loss due to malfunction, present options with quantifiable effects for decision-making, and take actions, and assess the outcomes. The objectives consist of:
Developing a generic platform for the monitoring energy consumption of industrial equipment using sensors
Control the connected equipment using an actuator
Integrating hardware, cloud, and application algorithms into the platform
Validating the system using an Energy Consumption Forecast scenario
A Demo station was created for testing the system. The demo station consists of equipment such as air compressor, motor and light bulb. The current usage of these equipment is measured using current sensors. Apart from current sensors, temperature sensor, pres- sure sensor and CO2 sensor were also used. Current consumption of these equipment was measured over a couple of days. The control system was tested randomly by turning on equipment at random times. Turning on the equipment resulted in current consumption which ensured that the system is running. Thus, the system worked as expected and user could monitor and control the connected equipment remotely.
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(6008088), Sreemoyi Debroy. "CAN SIMULATION SOFTWARE INTEGRATED WITH GAMIFICATION ENHANCE STUDENTS’ UNDERSTANDING OF PROJECT EXECUTION CONCEPTS BY IMPROVING LEARNING OUTCOMES?" Thesis, 2019.
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This research study explores the gamification of SandBoxModel's Project Team Builder, a project management simulation software. Scope, time and cost are the three constraints of project management with quality being the fourth dimension. The software provides a simulated environment where the students are responsible for handling the aforementioned constraints with the objective of executing a complete project. The software is used to teach project management concepts to students who take the CNIT 480 - Managing Information Technology Projects course at Purdue University. The perception survey was used to analyze whether gamification had a significant effect on student understanding of project execution concepts. The triple constraint survey was used to analyze students' level of comprehension regarding the triple constraints after using the simulation software. Gamification was not a success in enhancing project execution concepts since no significant differences were found in student perceptions on comparing the data of the three semesters. However, simulation independent of gamification was successful in improving students' understanding of triple constraint.
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(5930396), Jack D. Williams. "Magnetically-Coupled Circuits Systems for Wireless Excitation of Passive Stimulators for Stimulation Therapies and Application as a Treatment for Glaucoma." Thesis, 2019.
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The practice of delivering an electrical current waveform to an excitable tissue such as a structure in the brain, nerve fiber, or muscle to relieve the symptoms of disease constitutes an electrical stimulation therapy. Electrical stimulation therapies supported by implantable devices provide effective treatment options for people suffering from treatment-resistant chronic diseases that often fail to respond to medication and other traditional therapies [1, 2]. However, implantable electrical stimulators traditionally approved by the Food and Drug Administration (FDA) use implanted batteries that require surgical replacement over years of operation and limit therapies to applications with minimal constraints on implant mass, volume, and rigidity [3, 4]. Previous works have proposed to eliminate batteries in implantable stimulators by using magnetically-coupled coils to deliver energy through radio-frequency (RF) fields, exciting alternating currents on implantable devices to be converted into stimulus pulses by rectifiers [5, 6]. Implantable stimulators without batteries may be excited by an alternative theory of operation without the use of RF fields that eliminates the need for a rectifier and permits stimulators with minimal complexity.
This work proposes an original use of magnetically-coupled circuits theory for the wireless excitation of electrical stimulation current waveforms on passive stimulators that eliminates the need for an implanted battery. The principle of the technique is to drive stimulation current waveforms on passive stimulators with electromotive forces excited by applied time-varying magnetic fields via the phenomena described by Faraday’s law of induction [7-9]. The proposed systems require a wearable driving component and a passive driven component that may either be worn or implanted. The wearable driving component must include a battery, pulse-generating circuitry, and a primary coil, whereas the driven component is a passive device requiring only a secondary coil with electrodes to contact tissue. The pulse-generating circuitry of the driving component may be implemented readily such that the design of the coils defines the challenge in the implementation of the proposed systems. The design of the coils for the proposed systems presents the potential for a nontrivial optimization problem with conflicting objectives; possible objectives for the design of the coils include maximizing the attainable peak amplitudes of the stimulation currents, obtaining various characteristics of a desired stimulation current waveform, and minimizing the variation of the stimulation currents with varying displacements between the coils. The problem posed by the design of the coils for the proposed systems is addressed by direction obtained from theoretical analyses and experiments performed in this work that supplement direction from the literature [5, 10-12]. The potential utility of the proposed theory of operation is demonstrated by enabling the first chronic electrical stimulation therapy for glaucoma, the leading cause of irreversible blindness worldwide. The system designed for the glaucoma stimulation therapy and the methods used to quantify its electrical performance are presented along with data from experimental therapeutic trials with human participants.
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(5930270), Mehdi Shishehbor. "Numerical Investigation on the Mechanical Properties of Neat Cellulose Nanocrystal." Thesis, 2020.
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Nature has evolved efficient strategies to make materials with hierarchical internal structure that often exhibit exceptional mechanical properties. One such example is found in cellulose, which has achieved a high order of functionality and mechanical properties through a hierarchical structure with an exceptional control from the atomic level all the way to the macroscopic level. Cellulose is present in a wide variety of living species (trees, plants, algae, bacteria, tunicates), and provides the base reinforcement structure used by organisms for high mechanical strength, high strength-to-weight ratio, and high toughness. Additionally, being the most abundant organic substance on earth, cellulose has been used by our society as an engineering material for thousands of years, and are prolific within our society, as demonstrated by the enormity of the world-wide industries in cellulose derivatives, paper/packaging, textiles, and forest products.
More recently, a new class of cellulose base particles are being extracted from plants/trees, cellulose nanocrystals (CNCs), which are spindle-shaped nano-sized particles (3 ̶ 20 nm in width and 50 ̶ 500 nm in length) that are distinct from the more traditional cellulose materials currently used (e.g. molecular cellulose and wood pulp). They offer a new combination of particle morphology, properties and chemical functionalities that enable CNCs for use in applications that were once thought impossible for cellulosic materials.
CNCs have shown utility in many engineering applications, for example, biomedical, nanocomposites, barrier/separation membranes and cementitious materials. To gain greater insight as to how best use CNCs in various engineering application areas, a comprehensive understanding of the mechanics of CNCs is needed. The characterization of the mechanical properties of nanomaterials via experimental testing has always been challenging due to their small size, resulting in large uncertainties related to testing near sensitivity limits of a given technique, the same is true when characterizing CNCs. For CNCs, to help offset limitations in experimental testing, numerical modeling has been useful in predicting the mechanical properties of CNCs. We present a continuum-based structural model to study the mechanical behavior of cellulose nanocrystals (CNCs), and analyze the effect of bonded and non-bonded interactions on the mechanical properties under various loading conditions. In particular, this model assumes the uncoupling between the bonded and nonbonded interactions and their behavior is obtained from atomistic simulations.
For large deformations and when there is interaction and dynamics of many particles involved, continuum models could become as expensive as MD simulations. In addition, it has been shown that traditional material models in the continuum mechanics context, cannot model all the mechanical properties of CNC, especially for large deformation. To overcome these setbacks and to be able to model real size of CNC, 50-1000 nm, and/or to increase the number of particles involved in the simulation, a so called ‘‘coarse-grained’’ (CG) model for mechanical and interfacial properties of CNC is proposed. The proposed CG model is based on both mechanical properties and crystal-crystal interactions. Parametrization of the model is carried out in comparison with all-atom (AA) molecular dynamics and experimental results of some specific mechanical and interfacial tests.
Subsequently, verification is done with other tests. Finally, we analyze the effect of interface properties on the mechanical performance of CNC-based materials including, bending of a CNC bundle, tensile load and fracture in bioinspired structure of CNCs such as staggered brick-and-mortar and Bouligand structures of interest.
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(13753927), S. Vijay Sundhar. "Endurance limit determination in porous materials." Thesis, 1992. https://figshare.com/articles/thesis/Endurance_limit_determination_in_porous_materials/21047392.
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The theory describing the fatigue mechanism in elasto-plastic material containing pores or inclusions has been developed. An attempt at quantitative determination of the effect of endurance limit reduction by analysis of sizes of plastic zones formed near the inclusions, and their cracking has been -done. The geometrical configuration, consisting of round, horizontal, vertical and angular elliptical inclusions from which a nucleating crack emerged, was considered, and the stress intensity factory of such configurations was analysed. Based on threshold value of 6K below which crack propagation ceases, the critical value of loading stress was determined. Finite element technique was used to obtain theoretical results. A source code developed by Owen and Hinton for solving elastoplastic applications using finite element concept was used for solving the problem. Experimental analysis was done using photoelasticity method. Theoretical results were compared with results from experiments, showing quite good agreement.
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(11186220), Julianna Gesun. "Beyond Surviving: Developing and Testing a Model of Thriving for Engineering Students." Thesis, 2021.
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The goal of my dissertation is to take a step toward shifting the narrative in engineering from “surviving” to “thriving” so that more engineering students can reach their full potential in college and beyond. Many engineering students experience barriers such as the hardships of engineering culture, which are exacerbated for women and underrepresented racial/ethnic minorities(such as Black, Latinx, and Indigenous students). These barriers are well documented in research and well discussed in interventions to support engineering student success, under the assumption that helping students cope with these cultural and systemic barriers will, by itself, lead to their success. My research on engineering thriving challenges this assumption by asserting that the skills engineering students need to succeed academically, socially, and personally differ from the skills they need to “survive” cultural and systemic barriers.This dissertation employs an exploratory multiphase research design, with three studies, to develop a model of thriving for undergraduate engineering students. The first study consists of a scoping literature review of 68 papers to define and characterize engineering thriving as the process in which engineering students develop and refine competencies that allow them to function optimally in engineering programs. From this definition, the second study employs a Delphi process with 47 experts to develop a model of engineering thriving that includes 1) internal thriving competencies; 2) external thriving outcomes; 3) engineering culture, systemic factors, resources, context and situation; and 4) how these three broader categories function together. The third study tests some of these relationships proposed in the model of engineering thriving using structural equation modeling(SEM) on a large dataset of responses by over 2,000 undergraduate U.S. engineering students to a survey that measured various constructs associated with thriving. Findings from the SEM analysis suggest that gratitude was one of the most important competencies for engineering student thriving, and that a holistic model approach accounted for 79% of the variance in engineering students’ belongingness and 25% of the variance in perceptions of faculty caring(two external thriving outcomes).
Understanding and supporting more engineering thriving has positive implications for students, recruitment and outreach, and engineering programs. Thriving is multidimensional and, thus, supporting engineering students to achieve traditional success metrics (such as academic performance and graduation) goes hand in hand with supporting their personal and social development and wellbeing. Recruitment and outreach of K-12 students can benefit from viewing engineering as an attractive and inspirational career, combating negative stereotypes that currently deter students from pursuing engineering. Engineering programs can benefit from developing a reputation and culture of thriving. However, cultural change requires the collective investment from all members of the engineering community.
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(10716507), Alexis Margaret Corda. "Advancements of a Silicon-on-Insulator Thermoelectric Sensor for Biomedical Applications." Thesis, 2021.
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Heat can be used as a reliable biomarker of cell metabolism. Assessing changes in metabolic activity is useful to study normal bioactivity or factors which may stimulate or inhibit cell proliferation. Methods which measure the heat of cell metabolism over time must be sensitive to the small changes. Thermoelectric sensors, which work by the Seebeck effect, are one method which has shown adequate sensitivity. This type of sensor directly converts heat energy into electrical energy without the use of a power source. Current research into sensors for cell metabolism may list lengthy, complex, and expensive procedures or include materials with rare or toxic elements. This work establishes a design approach of a silicon-based thermoelectric sensor for cell metabolism measurement which incorporates abundant and non-toxic materials and a simple procedure based on standard MEMS fabrication methods. The foundation for the sensor design is discussed. Fabrication was done using optical lithography, reactive ion etching, and electron beam evaporation which are standard and well known in industry. Sensor quality was characterized successfully based on the defined design parameters. Preliminary data has been recorded on the Coli cell metabolism. Finally, recommendations to improve heat insulation, include sensor calibration, and optimize manufacturing parameters are given for future work on this design to advance sensitivity and commercial potential.
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(9776462), A. K. M. Shamsul Akan. "Abrasion failure of lining rubber on agitator blades in the leaching circuit of mineral processing industries." Thesis, 2005. https://figshare.com/articles/thesis/Abrasion_failure_of_lining_rubber_on_agitator_blades_in_the_leaching_circuit_of_mineral_processing_industries/13420268.
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"The failure of agitator blades was an issue of major concern in the leaching circuit of the Australian Magnesium Corporation (AMC) pilot plant in Gladstone. The aim of this project was to investigate the causes of the failure of the agitator blades and to make some recommendations to help avoid the problem in the future." -- abstract. The failure of agitator blades was an issue of major concern in the leaching circuit of the Australian Magnesium Corporation (AMC) pilot plant in Gladstone. The aim of this project was to investigate the causes of the failure of the agitator blades and to make some recommendations to help avoid the problem in the future. At the start of this thesis, a comprehensive failure analysis was carried out in order to understand the potential failure mechanisms operating in the slurry tanks. A number of potential failure mechanisms were identified and these included erosive slurry wear of the rubber and chemical and/or thermal degradation of the rubber. These failure mechanisms may also act synergistically. An experimental programme of research was planned to investigate the separate influences of slurry wear and chemical and/or thermal degradation of the rubber. The results of these tests were then used to extend our understanding of the failure of the agitator blades. A slurry erosion test has been developed in order to quantify the erosion of bromobutyl rubber. The study investigated the effects of particle size, erosion time, slurry weight concentration and specimen velocity. Wear was measured using surface roughness measurements and scanning electron microscopy (SEM) of the worn surfaces. The degree of wear was found to increase with increased particle size, slurry weight concentration and erosion time and the wear appear to be at a maximum at a nominal angle of impact of the particles of approximately 40°. Wear appeared to decrease with increasing slurry velocities, but this may have been due to changes in particle shape. One of the key factors in the development of damage on the surface of the rubber was found to be wear of the abrading particles and the condition of the abrading particles needs to be taken into account when interpreting the results of slurry wear tests. In general the experimental results were found to be in good agreement with the predictions from the literature and a model has been developed in order to obtain a better understanding of slurry erosion. In addition to the slurry wear tests, the chemical degradation behaviour of In addition to the slurry wear tests, the chemical degradation behaviour of bromobutyl rubber was investigated by measuring hardness (shore A) and surface morphology of the rubber after exposure of the rubber to acid and water at 70°C. In acid, the rubber hardness increased with time and whereas in water alone, the rubber hardness decreased. This indicated that the acid immersion had a hardening effect on the rubber and this may have played some part in the failure. From this work, it is apparent that both slurry wear and exposure to acid andlor temperature have an effect on the degradation of the rubber. Particle size and shape had a major effect on damage accumulation rates, with most damage occurring with large, sharp particles. For tests where the particle size was below 3.35 mm the damage accumulation rate was insignificant. Morphological studies of the worn surfaces suggest that a major mechanism of damage was the formation of cracks which penetrated the rubber and exposed the underlying steel agitator blades to the acidic environment. Hardening of the rubber by exposure to the acid solution would have decreased the resilience of the rubber and may have increased the effect of the slurry wear on crack formation, but at this stage the coupled effects of slurry wear and chemical/thermal degradation have not been explored.
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(9874682), L. Allahmanli. "Integrated multi-criteria hierarchical asset performance measures for transmission network service providers." Thesis, 2012. https://figshare.com/articles/thesis/Integrated_multi-criteria_hierarchical_asset_performance_measures_for_transmission_network_service_providers/13457114.
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" Electricity transmission assets can be defined as the networks supplying high voltage of electricity to customers where the system as a whole intended to be maintained for a longer asset life at a specified level of service by continual replacement and refurbishment of its components...Effective asset management enhances performance, reduces cost and risk within asset life cycle. Achieving this goal requires careful classification of hierarchical levels of decision-making throughout the life cycle phases of the assets. In this study, these levels are defined and used as performance enhancement tool with the application of maturity measurment principles"--Abstract.