To see the other types of publications on this topic, follow the link: Complex technology.
Dissertations / Theses on the topic 'Complex technology'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Complex technology.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Lowe, Martin. "Modelling landfill as a complex biophysical technology." Thesis, Cranfield University, 1998. http://dspace.lib.cranfield.ac.uk/handle/1826/10637.
Full textAbstract:
Concerns regarding climate change are becoming a driver behind legislation at both
UK and EU levels, and also on the wider, planetary scale This is the case with
emissions from landfills where the release of methane is being targeted for reduction
This thesis uses an integrative approach, incorporating concepts of hierarchy from
systems theory, to model landfill as a complex biophysical technology It assesses the
contribution to carbon deposition and global warming of landfill through changes to
that technology itself and through changes in the waste stream caused by potential
waste policies
The thesis develops an holistic, conceptual model of the landfill system, mapping
flows and transformations of carbon within that system It further develops this
conceptual model into a calculating model of landfill as a waste management
technology incorporating measurements taken to provide new data and validate
published data to calibrate the model It thus applies modelling techniques to a
biophysical technology, producing an integrated model of the landfill that allows the
knowledge gained from other research to be used to explore engineering and
operational decisions on landfills
The thesis includes results from measurements of the composition of household
waste, and of the biochemical methane potential (BMP) of fractions of that waste It
includes measurements of the residual BMP in samples of excavated waste and
measurements of gas flows
The main results suggest the following
• Early capping of landfilled waste is important in reducing the global warming
impact,
• If the rate of degradation of the waste is accelerated in the drive towards
sustainability, capping should be carried out even earlier if the global impact is not
to be increased,
• Although recycling parts of the degradable elements of the waste stream has the
effect of reducing the global impact, extensive recycling has implications for
landfill engineering
2
Carter, Simon Matthew James. "Changing complex documents /." St. Lucia, Qld, 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16479.pdf.
Full text
3
Грищенко, Юрій Віталійович. "ANALYTICAL STUDIES OF COMPLEX TECHNOLOGY INTERRUPTIONS OF AVIONICS." Thesis, Національний авіаційний університет, 2013. http://er.nau.edu.ua/handle/NAU/11518.
Full textAbstract:
Currently, it is provided avionics of modern aircrafts is a very reliable, which is asso¬ciated with a complete set of modern microelectronics. However, modern digital techniques is sometimes there are some interruptions that impact on safety. Ways for solving this negative phenomenon dedicated our report.
4
Aragon, Lasumar (Mark) R. "Technology insertion considerations for complex system of systems development." Thesis, Monterey, Calif. : Naval Postgraduate School, 2008. http://edocs.nps.edu/npspubs/scholarly/theses/2008/Sept/08Sep%5FAragon.pdf.
Full textAbstract:
Thesis (M.S. in Systems Engineering)--Naval Postgraduate School, September 2008.Thesis Advisor(s): Paulo, Eugene. "September 2008." Description based on title screen as viewed on October 31, 2008. Includes bibliographical references (p. 63-64). Also available in print.
5
Theodoreli-Riga, C. V. "Evaluation of robotic catheter technology in complex endovascular intervention." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/11627.
Full textAbstract:
The past four decades have witnessed tremendous strides in the evolution of endovascular devices and techniques. Catheter-based intervention has revolutionized the management of arterial disease allowing treatment of aortic and peripheral pathologies via a minimally invasive approach. Despite the exponential advances in endovascular equipment, devices and techniques, catheter-based endovascular intervention has certain morphological and technological constraints. Complex patient anatomy, technological impediments and suboptimal fluoroscopic imaging, can make endovascular intervention challenging using traditional endovascular means. Conventional endovascular catheters lack active manoeuvrability of the tip. Manual control can hinder overall stability and control at key target areas, leading to significantly prolonged overall procedure and fluoroscopic times. Repeated instrumentation increases the risk of vessel trauma and distal embolization. More importantly, guidewire-catheter skills are not necessarily intuitive but must be developed and are highly dependent on operator skill with long training pathways as a result. Recognizing the pressing need to address some of the limitations of standard catheter technology this thesis aims to evaluate the role of advanced robotic endovascular catheters in the aortic arch and the visceral segment. Clinical use of this technology is currently limited to transvenous cardiac mapping and ablation procedures. A comprehensive pre-clinical comparison and analysis of robotic versus manual catheter techniques is presented to reveal both their advantages and limitations, with particular emphasis on the potential of robotic catheter technology to reduce the manual skill required for complex tasks, improve stability at key target areas, reduce the risk of vessel trauma, embolization and radiation exposure, whilst improving overall operator performance. The worlds first clinical report of robot-assisted aortic aneurysm repair, a “proof - of - concept” resulting from this research, is also presented, and the potential for future advanced applications in order to increase the applicability of endovascular therapy to a larger cohort of patients discussed.
6
King, Melanie R. N. "The realist evaluation of educational technology." Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/27554.
Full textAbstract:
PURPOSE. This thesis considers the best way to address the challenges faced by educators, institutions and funding bodies trying to not only develop and implement educational technology successfully but tackle the challenge of understanding and evidencing what works (and what does not) and why. The aim of the research was to find and validate an evaluation method that provided usable and useful evidence. APPROACH. A range of evaluations were undertaken to elicit the strengths and weaknesses of different approaches, augmented by drawing upon the experiences and outcomes published by others. An analysis of the issues was made and significance of the problem established. The problem being premature timing, unsuitable models, rapid change, complex implementation chains, inconsistent terminology, ideology and marketisation. A tailored realist evaluation framework was proposed as an alternative method and it was tested to evaluate an institutional lecture capture (LC) initiative. FINDINGS. The theory-driven realist approach provided a level of abstraction that helped gather evidence about wider influences and theories of potential future impact of the LC programme and its linked policy. It proved valuable in generating real and practical recommendations for the institution, including what more could be done to improve uptake and support embedding in teaching and learning, from practice, policy and technological points of view. It identified some unanticipated disadvantages of LC as well determining how and when it was most effective. PRACTICAL IMPLICATIONS. A Realist Evaluation of Technology Initiative (RETI) framework has been produced as tool to aid the rapid adoption of the approach. Recommendations for future research and seven guiding principles have been proposed to encourage the formation of a community of realist evaluative researchers in educational technology. ORIGINALITY/VALUE. The rigorous application of a tailored realist evaluation framework (RETI) for educational technology (including the development of two Domain Reference Models) is the primary contribution to new knowledge. This research is significance because it has potential to enable the synthesis of evaluation findings within the sector. This will enable an evidence-base of what works, for whom, in which contexts and why, ultimately benefiting policy-makers and practitioners to support better informed decision making and investment in education.
7
Al-Sharify, Zainab Talib Abidzaid. "Flow and mixing of complex fluids." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7673/.
Full textAbstract:
The mixing of complex fluids in stirred reactors is widly used in many industries. Mechanically agitated vessels are widely used in these industries such as wastewater treatment, pharmaceuticals, nuclear and food processing. Complex fluids are frequently encountered in these industries. There is growing interest in developing and studying these fluids, especially for those of shear thickening (ST) behaviour, due to the importance of their industrial applications such as flexible body armor and force damping applications which can protect a person from danger or risk and ultimately saveone’s life. Little work has been done to understand how to mix complex fluids effectively, mainly because of their opaque nature. In this thesis, new ST fluids formulations were developed and these fluids were used as a model fluid for mixing studies. The flow field in an opaque ST fluid was determined experimentally using the positron emission particle tracking (PEPT). In addition, the performance of axial, radial and mixed flow impellers in mixing complex fluids have been also studied using different experimental techniques and the computational fluid dynamics (CFD) simulations. Moreover, for the first time, PEPT has been used to investigate the flow field of floating particles in a stirred vessel. PEPT was used to investigate the two-phase flow field inside a stirred vessel of polypropylene particles in different types of rheological fluids, at the just drawdown speed for a wide range of solid concentrations from 1.8 vol% up to 46 vol%. The outcomes of this thesis are beneficial to many chemical processes, such as e.g. formulation processes in the pharmaceutical industry, whereby an essential step in the product development involving powder mixing is the ability to drawdown the floating solids. In addition, the outcome of this thesis can also be beneficial in identifying the ideal configuration of stirred vessels used in chemical processes where mixing is the central feature, for example, in the food and rubber industries. Moreover, the newly developed complex fluids (shear thickening fluids) can be used in many industrial and commercial applications such as in the defence industry (as liquid body armor) and also as part of the protective devices designed to minimise head and neck injuries that occur in some sports accidents such as in car racing, football, ice hockey etc.
8
Johnsson, Stefan. "Performance and performance measurements in complex product development." Licentiate thesis, Mälardalen University, School of Innovation, Design and Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-5608.
Full textAbstract:
In today’s competitive environment, in which competition increases and the pace of technological change accelerates, the need for deploying product development investments more efficiently and effectively is stronger than ever. The ability to create streams of new successful products to the market is vital for every product delivering company’s survival. Performance measurements are important in order to evaluate the current state of operation of the product development and decide on actions to improve its’ performance. However, in contrast to the concept of productivity in the production process there are no commonly adopted methods for measuring performance within product development. The methodology used in this research is explorative multiple case studies at five companies developing complex products. Complex products in this research involve mechanics, electronics, and software. Moreover, complex products are often long living and most development work is evolutionary in character. An extensive interview study among senior managers and decision makers has been conducted to get a broad and systematic understanding of what performance is and what to measure. The main results developed from this research are two conceptual tools. The first one, the Performance Measurement Evaluation Matrix (PMEX) can be used to evaluate the performance measurement system used at a company. The PMEX makes it possible for managers to get a more holistic view and discuss what the performance measurement system is measuring, and what it is not measuring, in order to decide on what to measure. The second tool, the Product Development Organizational Performance Model (PDOPM) can be used to conceptually analyze performance in the product development process from a holistic system perspective. This is achieved by making efficiency, effectiveness, and uncertainty explicit and by showing how they relate at a strategic, project, and product implementation level. The PMEX and the PDOPM can be used by managers in order to increase the understanding of what performance is and to be able to decide on actions in order to improve the performance of the product development process.
9
De, Leon Ellen Jane Biotechnology & Biomolecular Sciences Faculty of Science UNSW. "Engineering antibodies against complex platelet antigens using phage display technology." Awarded by:University of New South Wales, 2007. http://handle.unsw.edu.au/1959.4/37009.
Full textAbstract:
Platelets are small anucleate cell fragments found in blood whose physiological role is important in maintaining haemostasis. In vivo, platelet surface glycoproteins mediate the mechanistic roles of platelets, and polymorphic changes to these glycoproteins have been observed to have significant effects on the platelet cellular function and such changes may include over-expression, under-expression and antigenicity of the protein. Human platelet antigens (HPA) are a result of polymorphic differences in platelet surface glycoproteins which have been found to be variably expressed in the population. Foetal maternal alloimmune thrombocytopaenia (FMAIT) is a condition that is observed in the unborn foetus and neonates due to HPA incompatibility between the mother and the foetus. HPA incompatibility accounts for a majority of severe thrombocytopaenic cases in neonates, and delayed diagnosis and treatment of such a condition often lead to intracranial haemorrhage. The risk in neonates diagnosed with FMAIT becomes increasingly significant in cases where intra-uterine (during pregnancy) platelet transfusion is the only effective therapeutic option. There are currently no antenatal screening programs for this condition, and laboratory diagnosis of FMAIT relies on the detection of maternal alloantibodies and parental HPA typing. For these reasons a significant amount of research is currently being invested into the isolation of recombinant antibodies with specific reactivity against FMAIT-related platelet antigens. Stable and specific recombinant platelet antibodies have great potential as a diagnostic agent in antenatal screening and broad-scale HPA typing of blood donors for platelet transfusion. Further characterisation of the isolated antibody may lead to a possible therapeutic agent. Studies by previous researchers have shown that the traditional methods (ie. Mouse monoclonal and EBV transformation) of obtaining monoclonal antibodies against FMAIT-related antigens have proven unsuccessful. The continuing progress in the discipline of phage display has produced several novel antibodies against self and non-self antigens. A further advantage in the application of phage display technology for the isolation of novel antibodies is the easy transition from bacterial to mammalian expression for the characterisation of glycosylated antibodies. The main focus of this project was to create and isolate a recombinant human anti-HPA-3a antibody using phage display for its possible application as a therapeutic or diagnostic agent.
10
Letaba, Tshotleho Petrus. "Complex Technology Roadmap Development in the Context of Developing Countries." Thesis, University of Pretoria, 2018. http://hdl.handle.net/2263/64412.
Full textAbstract:
Technology roadmaps are useful for much longer technology planning periods in which past performance might not determine the future. They are also very useful in translating strategies into implementable actions, with clear targets and timelines. A growing number of organisations, industry associations, national governments and international agencies are also using technology roadmaps for future technology planning and analysis.
This research responds to the complexities associated with technology roadmap development in South Africa and other developing countries. It seeks to investigate whether the predominant literature on technology roadmaps and technology roadmapping is suitable for developing countries or if the existing frameworks need to be customised to suit framework conditions for developing countries. The following are the main research questions: 1) what are the unique framework conditions for innovation in developing countries and 2) what is a suitable technology roadmapping framework for developing countries? The research sub-questions associated with the first research question are 1) what are the main priorities for innovation in South Africa and 2) what are the actual/ perceived innovation competitive advantages for South Africa? The research sub-questions associated with the second research question are: 1) what is the nature and characteristics of technology roadmaps in South Africa and 2) what are the critical factors for successful technology roadmaps in South Africa?
Relevant literature reviewed in this research includes knowledge evolution of the technology roadmapping field, nature and impact of emerging technologies as well as technology management in developing countries. The mainstream technology roadmapping literature is useful in guiding technology roadmapping efforts in developing countries, although the intention of this study was also to determine its ‘fitness for purpose’. A literature review led to the development of the theoretical framework for technology roadmapping in developing countries. The key elements of this framework are the multilevel perspective analysis based on complex systems theory, transition management theory and leapfrogging as technology catch-up strategy.
The methodology adopted for this research was informed by a theoretical framework developed and a literature review. The research design is based on post-positivism research philosophy (realism perspective). As a result, both a quantitative survey and qualitative interviews were used to collect data. Data collection tools used were online quantitative survey as well as semi-structured qualitative interviews. The information collected from qualitative interviews along with secondary data (documents analysis) were used to assist in interpreting patterns of responses received from quantitative survey data.
The five deduced analytical propositions regarding the innovation dynamics in South Africa, as a case for developing countries, address the key issues to consider in transitioning the complex innovation systems. Building from the findings regarding the innovation dynamics within the developing countries, the additional five propositions provide some foundation and principles for technology roadmapping in developing countries. These incorporate usage of the third generation technology roadmaps in the developing countries, importance of timing the window of opportunity, the recommended usage of scenario planning, a balance between involvement of stakeholders from dominant product-technology platform and those who are transition-oriented and the importance of monitoring and updating the transition-based technology roadmaps.
The ten analytical propositions deduced were further tested and demonstrated through the analysis of sociotechnical transitions taking place within the energy, mining and water sectors in South Africa. The common innovation landscape factors that are incorporated for long-term technology planning in these sectors are the economic climate, government policy and public discourse. All three plans also begin with a transition phase that entails predevelopment of multiple emerging technologies that are characteristic of the third generation technology roadmaps.Thesis (PhD)--University of Pretoria, 2018.
Department of Science and Technology
Eskom Tertiary Education Support Programme (TESP)
Graduate School of Technology Management (GSTM)
PhD
Unrestricted
11
Price, Tobias E. C. "Multi-component complex hydrides for hydrogen storage." Thesis, University of Nottingham, 2010. http://eprints.nottingham.ac.uk/11988/.
Full textAbstract:
Hydrogen as an energy vector offers great potential for mobile energy generation through fuel cell technology, however this depends on safe, mobile and high density storage of hydrogen. The destabilised multi-component complex hydride system LiBH4 : MgH2 was investigated in order to characterise the destabilisation reactions which enable reduction of operating temperatures for this high capacity system (ca. 9.8 wt.%). In-situ neutron diffraction showed that regardless of stoichiometry similar reaction paths were followed forming LiH and MgB¬2¬ when decomposed under H¬2 and Mg-Li alloys (Mg0.816Li0.184 and Mg0.70Li0.30) when under dynamic vacuum. Hydrogen isotherms of the 0.3LiBH4 : MgH¬2¬ showed a dual plateau behaviour with the lower plateau due to the destabilised LiBH4 reaction. Thermodynamic data calculated from the isotherm results showed a significant reduction in the T(1bar) for LiBH4 to 322 C (cf. 459 C for LiBH4(l)). Cycling behaviour of 0.3LiBH4 : MgH2 system decomposed under both reaction environments showed very fast kinetics on deuteriding at 400C and 100 bar D2, reaching 90 % conversion within 20 minutes. In contrast 2LiBH4 : MgH2 samples had kinetics an order of magnitude slower and after 4 hours conversions <50 %. These results demonstrate the strong influence of stoichiometry in the cycling kinetics compared to decomposition conditions. Investigation of catalysts found dispersion of metal hydrides through long ball-milling times, or dispersion through reaction with metal halide additions provided the greatest degree of kinetic advantage, with pre-milled NbH providing the best kinetic improvement without reducing capacity due to Li-halide formation. Finally, additions of LiAlH4 to the system formed an Al dispersion through the sample during decomposition, which acted both as a catalyst and destabilising agent on the MgH2 component, forming Mg-Al-Li alloys. Decomposition under H2 also showed a destabilisation effect for the LiBH4 component.
12
KING-NYGREN, ELIAS. "Analysis of Complex 3D-Concrete Casting." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299789.
Full textAbstract:
Concrete is the second most used material in the world and is primarily used within the construction industry. It is however also used for making decorative and functional smaller products within various industries. Manufacturing with concrete can be done with different manufacturing techniques, the most common technique being concrete casting in molds. This project was conducted at Arclight AB in Stockholm, a company on the verge of starting production of molds for casting concrete products. With many different manufacturing techniques at their disposal, it is however difficult for them to know which manufacturing technique should be used for which type of mold. The goal of this project is to compare the available manufacturing techniques at Arclight and see which are most suitable for mold manufacturing. The background research and preparation resulted in three segments of the casting process which needed to be analyzed: choice of concrete, choice post-processing technique, and choice of manufacturing technique. Results from the trails of these three segments gave invaluable information for the project. Concrete trails resulted in a recommendation of a concrete with high compression strength and high water content to make the concrete viscous and flow easily into the mold. Post-processing trials resulted in different optimal post-processing techniques based on the mold material and manufacturing technique. Manufacturing trails gave in-depth information on processing larger molds and the potential problems associated with casting complex large concrete products. The final result of the project is a spreadsheet which recommends an optimal manufacturing technique based on the geometry type and number of products to be cast. Maximum cost per product, maximum machine time for manufacturing and maximum total production time for the concrete products are also stated to find the optimal manufacturing technique for each specific concrete casting project. Before using this spreadsheet as a basis for manufacturing, it should be formatted for easier use. Additional tests with applying epoxy and polyurethane resin for post-processing molds should be conducted, in addition to testing materials for manufacture of master molds for vacuum forming.Betong är det näst mest använda råmaterialet i världen och används primärt inom byggindustrin. Det används även för tillverkning av estetiska och funktionella mindre produkter inom andra industrier. Betongprodukter kan tillverkas med flera olika tillverkningstekniker, där den vanligaste är gjutning av betong i gjutformar. Detta projekt var utfört hos Arclight AB i Stockholm, ett företag som är i början av att starta produktion av gjutformar för gjutning av betongprodukter. Med så många olika tillverkningstekniker hos företaget är det svårt att veta vilken tillverkningsteknik som är bäst lämpad för vilken typ av gjutform. Målet med detta projekt är att jämföra de olika tillverkningstekniker Arclight har och se vilka är mest lämpade för tillverkning av gjutformar. Bakgrundsforskningen och förberedandet resulterade i tre segment av gjutprocessen som behövde analyseras; val av betong, val av ytbehandlingsteknik, och val av tillverkningsteknik. Testerna inom dessa tre segment gav ovärderlig information för projektet. Resultatet av betongtesterna var en rekommendation av betong med hög tryckhållfasthet och en stor mängd vatten i betongen för lättare hällning i gjutformen. Resultatet av ytbehandlingstesterna var olika optimala ytbehandlingar beroende på material för gjutformen, samt tillverkningsteknik. Resultatet av tillverkningstesterna gav information om stora gjutformar bäst hanteras och eventuella problem associerade med att gjuta stora komplexa betongprodukter. Slutgiltiga resultatet av projektet är ett kalkylblad vilket rekommenderar optimala tillverkningsmetoden baserat på geometritypen av produkten som ska gjutas samt antalet produkter att tillverka. Maximal kostnad per produkt, maximal maskintid för tillverkning och maximal total tillverkningstid för produktion av betongprodukterna bestäms även för att finna optimala tillverkningstekniken för varje specifikt betonggjutningsprojekt. Innan detta kalkylark används för tillverkning borde det formateras så det är mer användarvänligt. Ytterligare ytbehandlingstester med epoxyresin och polyuretanresin bör göras på gjutformar, samt även att testa material för tillverkning av formverktyg för vakumforming.
13
Pettersson, Karl. "Design Automation of Complex Hydromechanical Transmissions." Licentiate thesis, Linköpings universitet, Fluida och mekatroniska system, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-99382.
Full textAbstract:
This thesis proposes an automated methodology for the design of complex multiple-mode hydromechanical transmissions. High fuel prices and strict emission regulations are today drivers of the development of new fuel-efficient drive transmissions for construction machinery. Hydromechanical transmissions have high energy efficiency and a wide torque/speed conversion range. They are today strong candidates to replace the fuel-thirsty torque converters conventionally used in heavy construction machines. The trend towards more complex transmission architectures increases the need for more sophisticated product development methods. Complex multiple-mode transmissions are difficult to design and prototype and can be realised in a great number of different architectures. This increases the need for reliable concept evaluation in early design stages. The design of the transmission is also strongly coupled to its energy consumption and for a fair comparison between transmission concepts optimal designs are necessary. Design automation and optimisation with detailed simulation models can support the industrial engineer in the design task and increase the available knowledge early in the design process. The proposed methodology uses simulation-based optimisation to design the transmission for a specific vehicle application. Various aspects of the transmission’s characteristics may be targeted, although energy efficiency is in great focus in this work. To evaluate the energy efficiency, the transmission designs are simulated using backward-facing simulations with detailed power loss models. The methodology is applicable for designing the drive transmissions of construction machines and other mobile working vehicles such as agricultural machines, forest machines and mobile mining equipment.
14
Schwind, Michael. "Dynamic pricing and automated resource allocation for complex information services : reinforcement learning and combinatorial auctions /." Berlin : Springer, 2007. http://www.netlibrary.com/urlapi.asp?action=summary&v=1&bookid=197100.
Full text
15
Gatt, Alfred. "Biomechanical assessment of passive ankle joint complex dorsiflexion." Thesis, Staffordshire University, 2012. http://eprints.staffs.ac.uk/1991/.
Full textAbstract:
The measurement of ankle joint dorsiflexion is an important component of the clinical examination of the foot and is also an outcome measure often employed in research. Diagnosis of ankle equinus or limited ankle dorsiflexion is based solely on this measurement. Although a great majority of research papers in this field utilise normal clinical goniometers for obtaining the maximum ankle dorsiflexion angle (MADA) and important clinical decisions are based on these findings, there is overwhelming evidence that this method is highly unreliable. Thus this thesis aimed to investigate alternative methods of measuring ankle dorsiflexion and various issues that affect the MADA in order to obtain a clear picture of foot segment movement from which an Ankle Goniometer could be consequently designed and validated. Ten different techniques were identified that included various apparatuses designed specifically for measuring ankle dorsiflexion. However, during validation, their methodological quality would have benefitted from the use of an actual patient population and comparison with a reference standard, which caused papers to score poorly on methodological quality assessment. It was concluded that issues affecting this measurement and that needed to be researched further include: foot posture, the amount of moment applied and the stretching characteristics of the calf muscle tendon unit. Experiments within this study indicated that in adults, the mean maximum pronated angles were always higher than in other postures, with 8.27o difference between the pronated and supinated postures (p=0.032) and 5.78o between pronated and neutral (p=0.000). However, the reported difference between neutral and supinated (mean angle of 2.49o) is of little clinical significance. It was observed that the forefoot always travels through a greater angle than the hindfoot in all 3 foot postures, while the hindfoot to forefoot angle increases during the application of a moment, indicating that the ‘midtarsal joint locking mechanism’ cannot be applied to passive dorsiflexion of the foot. In adolescents, there are no significant differences in the mean MADA between the 3 postures, implying that this measurement technique may be performed in any of these postures. It was also concluded that there is no need to control moment applied during this measurement procedure to produce consistent results between raters and that the calf muscle tendon unit does not stretch significantly following brief repetitive passive stretching. ii An ankle goniometer that measured purely hindfoot movement by eliminating forefoot influence and that increased reliability by holding the foot in the chosen posture, was consequently designed. This was validated by synchronizing with an electrogoniometer and an optoelectronic motion capture system. Reliability testing, with the foot held in a supinated posture as opposed to the traditional Rootian method of placing the foot at subtalar joint neutral position, spanned a number of different trials, including intra-tester and inter-tester reliability studies utilising both controlled and uncontrolled conditions, in convenience samples of healthy participants and a random sample of patients. Reliability testing between 4 raters with little experience on the utilization of this device was finally conducted. It has been shown that the Ankle Goniometer is a valid and reliable device for measuring ankle joint complex dorsiflexion both in healthy adults and in a patient population.
16
Eesa, Muhammad. "CFD studies of complex fluid flows in pipes." Thesis, University of Birmingham, 2009. http://etheses.bham.ac.uk//id/eprint/413/.
Full textAbstract:
The flow of rheologically complex fluids in industrial equipment poses a number of challenges, not least from a modelling point of view. Research is needed to further understand and be able to predict the flow behaviour of such materials and to investigate ways of improving their processing. This work investigates the numerical modelling of complex fluids in three areas: flow and heat transfer under an externally imposed mechanical vibration, and steady-state solid-liquid flows as a first step in extending the vibration studies to these multiphase systems. Validated CFD simulations were used to study the effects of rotational and transversal mechanical vibrations on the pipe flow of viscous non-Newtonian fluids of the power-law, Bingham plastic, and Herschel-Bulkley types. Vibration frequencies in the sonic range of 0-300 Hz and linear amplitudes of 0-4 mm were used. The results showed that rotational and transversal vibrations give rise to substantial enhancements in flow for shear thinning and viscoplastic fluids, while shear thickening fluids experienced flow retardation. The flow enhancement was found to depend on vibration frequency and amplitude, fluid rheological properties, and pressure gradient. These vibrations can be effective at enhancing the flow of low to moderately viscous fluids in industries such as the confectionery industry. For extremely viscous fluids (consistency index ~10 kPa s\(^n\) and yield stress ~200 kPa), ultrasonic frequencies (> 16 kHz) were found to produce orders of magnitude enhancements in flow. These results suggest that vibration can increase the fluidity of highly viscous fluids in industrial applications such as polymer extrusion. Results are also reported for the effects of transversal vibration on heat transfer and temperature uniformity in Newtonian and non-Newtonian shear thinning fluids. Vibration was found to generate sufficient chaotic fluid motion that led to considerable radial mixing which translated into a large enhancement in wall heat transfer as well as a near-uniform radial temperature field. Vibration also caused the temperature profile to develop very rapidly in the axial direction, thus, reducing the thermal entrance length by a large factor, so that much shorter pipes can be used to achieve a desired exit temperature. These effects increased with both vibration frequency and amplitude but were more sensitive to the amplitude. Higher fluid viscosities required larger amplitudes and/or frequencies to achieve substantial temperature uniformity. These results have significant implications for processes where a wide temperature distribution over the pipe cross-section is undesirable as it leads to an uneven distribution of fluid heat treatment, such as in the thermal sterilisation of food products. A numerical study was also conducted of the laminar pipe transport of coarse spherical particles (d = 2-9 mm) in non-Newtonian carrier fluids of the power law type using an Eulerian-Eulerian CFD model. The predicted flow fields were validated by PEPT experimental measurements of particle velocity profiles and passage times, whilst solid-liquid pressure drop was validated using relevant correlations gleaned from the literature. The study was concerned with nearly-neutrally buoyant particles (density ~1020 kg m\(^{-3}\)) flowing in a horizontal or vertical pipe at concentrations up to 40% v/v. The effects of various parameters on the flow properties of such mixtures were investigated over a wide range of conditions. Whilst the effects of varying the power law parameters and the mixture flow rate for shear thinning fluids were relatively small over the range of values considered, particle size and concentration had a significant bearing on the flow regime, the uniformity of the normalised particle radial distribution, the normalised velocity profiles of both phases, and the magnitude of the solid-liquid pressure drop. The maximum particle velocity was always significantly less than twice the mean flow velocity for shear thinning fluids, but it can exceed this value in shear thickening fluids. In vertical down-flow, particles were uniformly distributed over the pipe cross-section, and particle diameter and concentration had little effect on the normalised velocity and concentration profiles. Pressure drop, however, was greatly influenced by particle concentration. These results can help in understanding and predicting the flow behaviour of such solidliquid mixtures in industrial applications, such as the conveying of particulate food suspensions.
17
Perry, Michael W., Todd D. Ford, and James L. Hogan. "Communication during complex humanitarian emergencies: using technology to bridge the gap." Thesis, Monterey, California. Naval Postgraduate School, 2002. http://hdl.handle.net/10945/5277.
Full textAbstract:
Approved for public release; distribution is unlimitedcal. Technology can play a significant role to enable information sharing between the various participants during CHEs. This thesis documents the development of a proof of concept that supports this. Current reports and user feedback were analyzed to determine requirements for a field-based system that could enhance the flow of information. The developmental process is presented including, requirements generation, group structure and information sharing, collaborative environments and the advantages of the virtual space. Based on a fictional relief operation, a web application was constructed and designated the Relief Operations Coordination Center (ROCC). Built on COTS technology and combined with commercially available collaboration tools, this application showcases the various uses of today's technology and how it can be used to facilitate information sharing during CHEs.
18
Ford, Todd D. Hogan James L. Perry Michael W. "Communication during complex humanitarian emergencies : using technology to bridge the gap /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FFord.pdf.
Full textAbstract:
Thesis (M.S. in Information Technology Management)--Naval Postgraduate School, September 2002.Thesis advisor(s): Nancy Roberts, Alex Bordetsky. Includes bibliographical references (p. 159-162). Also available online.
19
Hong, Jiaju. "An innovative application of nuclear magnetic resonance technology to complex flows." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/38599/.
Full textAbstract:
In the present work, an inter principle research is carried out on complex fluid flow and heat transfer, using an innovative technology Nuclear Magnetic Resonance (NMR), from the Department of Physics. To enhance heat transfer performance of complex fluid flow, the present work mainly focuses on two different parts, one is the adoption of nanofluid; the other is flow forces analysis through bionic engineering studies on plant water migration system. Nanofluids are attracting considerable attention from both academic and industrial communities. Comparing with conventional pure fluids or solutions, nanofluids have higher thermal conductivity, due to the high surface to volume ratio of nanoparticle and liquid interface, which exhibits a great potential in enhancing heat transfer performance in various occasions. It is believed that different types and concentrations of nanofluid could strongly affect the thermal performance, and a great number of papers have been published to illustrate the phenomenon. However, none has really focused on the possible concentration change of nanofluid while flowing. Otherwise, the thermal performance of nanofluid flow could never be quantified. In the present work, a novel method to measure the dynamic concentration of nanofluid is proposed, using NMR technology. The experiments were carried out with ferrofluid under different concentration and temperature. A new parameter T2* was introduced in the study. T2* is a relaxation time of the signals that is released by hydrogen atoms after Radio Frequency (RF). And this signal intensity can be strongly affected by nanofluids. Experiments were carried out to obtain the T2* of nanofluid in the pipe. An empirical equation based on T2* and temperature was proposed to calculate the concentration of nanoparticles. Then, experiments were carried out with flowing ferrofluid in pipe. The dynamic concentration was calculated with the empirical equation. And with the series of experiment, it is confirmed that the flowing nanofluid consists of an obvious concentration gradient, and thus cause different layers of thermal performance from boundary to central line of a laminar pipe flow. Furthermore, the experiment result also gives out a chance to investigate the mechanism of nanoparticle movement in laminar flow with the concentration gradient along radius. Bionic Engineering is another research field that has been more and more interesting to researches from various fields. Since life has been evolving for over millions of years, many functions in lives has become extremely high efficiency and adaptive. These functions can be very worthy for researchers to study and utilize in industries. For heat transfer in fluid flow, it is very important to enhance the flow pattern. And thus water migration system in plants become very attractive. Plant can take water from soil up to several metres high. Learning from the water migration process in plants has been attracting interests from scientist for over a hundred years. The water migration in plant stem, especially xylem, involves various driving forces including capillary effect, osmosis effect, Marangoni effect and transpiration effect, etc. This present work mainly focuses on the water transport process within xylem. As xylem system is simplified as micro channel, a mathematic model is presented based on micro channel theory, with critical analysis and simplification. With a simplified micro channel from xylem structure and the calculation using the model of water migration in xylem, the relationship between various forces and water migration velocity is identified. The velocity of water migration within the plant stem is considered as detail as possible using all major forces involved. And a full mathematical model is proposed to calculate and predict the velocity of water migration in plants. Comparison between the calculated result and experimental one is made, to confirm the accuracy of the mathematical model. The present work proved that the mathematical model should be enough to predict the water migration in plants, and could also be critical for future water transport prediction in complex fluid flow in industry applications such as heat pipe.
20
Attebo, Edvin. "Safe learning and control in complex systems." Thesis, Umeå universitet, Institutionen för fysik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-178164.
Full textAbstract:
When autonomously controlling physical objects, a deviation from a trajectorycan lead to unwanted impacts, which can be very expensive or even dangerous. Thedeviation may be due to uncertainties, either from disturbance or model mismatch.One way to deal with these types of uncertainties is to design a robust control sys-tem, which creates margins for errors in the system. These margins make the systemsafe but also lowers the performance, hence it is desirable to have the margins assmall as possible and still make the system safe. One way to reduce the margins isto add a learning strategy to the control system, which improves the model repre-sentation using previous data. In this thesis, we investigate a robust control systemcalled tube-based model predictive control and then combine it with an adaptivegain scheduling method as the learning strategy. The adaptive feature in the gainscheduling method reduces the model mismatch between the model representationand the true dynamics by tuning the control parameters in the gain schedule usinga data-driven framework. To test this design, a dot is controlled to follow a pathin a constrained environment, around an obstacle. The dot should complete thetrack repeatedly without violating any constraints or crash into the obstacle whilereducing the model mismatch. Our results show that the error from the modelmismatch decreases with time without the dot touching the obstacle or moving out-side the constraints. As the error decreases, the margins in the controller becomesmaller, which makes it possible to control the system in a more efficient way andstill guarantee that the system remain safe.
21
Kunio, Mie. "Optimizing registration of complex vascular geometries." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/104613.
Full textAbstract:
Thesis: Ph. D. in Medical Engineering and Medical Physics, Harvard-MIT Program in Health Sciences and Technology, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references.
Advances in imaging, such as coronary angiography, intravascular ultrasound, and optical coherence tomography, can improve procedural success and outcomes for endovascular catheter intervention, such as stent implantation. Yet, these imaging modalities are not universally embraced; and thus, optimization of stent implantation and management of the adverse outcomes remain challenging. This is partially because full adoption of complex imaging awaits methods to reconstruct precise 3D structure of lumen and implanted stent, and to track vascular responses to stent implantation over time in 3D. This thesis creates new methods for reconstruction and registration in 3D by melding disparate imaging modalities, coronary angiography and optical coherence tomography (OCT), that provide different 2D-plane information (longitudinal and cross-sectional) using widely-varied experimental models (static phantom models, preclinical swine model with controlled scenarios of stent implantation in coronary arteries, and clinical unbiased model of stent implantation). A 3D vessel centerline from coronary angiography serves as a fusion path for OCT to reconstruct 3D structures and as a registration path for the reconstructed 3D structures across time. The developed vessel centerline reconstruction method overcame current spatial and temporal alignment challenges, and demonstrated high reproducibility across imaging angles and throughout the cardiac cycle. Structural reconstruction by angiography-OCT fusion was established and improved to account for the cardiac motion, reducing error in estimation of the stent length from 5.5% ± 4.5% with standard fusion to 2.4% ± 2.0%. Time-point registration was accomplished by detecting landmarks that are least affected by the vascular responses - its error, i.e., stent-strut shift from post-implantation to follow-up, was 1.6 mm ± 0.5 mm (9.2% ± 3.0% of the stent length). These methods were validated in a clinical setting and the errors of all methods were within those in the preclinical setting, suggesting potential for clinical applicability.
by Mie Kunio.
Ph. D. in Medical Engineering and Medical Physics
22
Li, Mi. "Preliminary crystallization and characterization of lectin-sugar complex." Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/27569.
Full text
23
Tuch, David Solomon 1973. "Diffusion MRI of complex tissue structure." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8348.
Full textAbstract:
Thesis (Ph. D.)--Harvard--Massachusetts Institute of Technology Division of Health Sciences and Technology, 2002.Includes bibliographical references.
Magnetic resonance diffusion imaging provides an exquisitely sensitive probe of tissue microstructure. Owing to the microscopic length scale of diffusion in biological tissues, diffusion imaging can reveal histological architecture irresolvable by conventional magnetic resonance imaging methods. However, diffusion imaging methods to date have chiefly been based on analytical models of the underlying diffusion process. For example, diffusion tensor imaging assumes homogeneous Gaussian diffusion within each voxel, an assumption which is clearly invalid for the vast majority of the brain at presently achievable voxel resolutions. In this thesis I developed a diffusion imaging method capable of measuring the microscopic diffusion function within each voxel. In contrast to previous approaches to diffusion imaging, the method presented here does not require any assumptions on the underlying diffusion function. The model-independent approach can resolve complex intravoxel tissue structure including fiber crossing and fiber divergence within a single voxel. The method is capable of resolving not only deep white matter intersections, but also composite tissue structure at the cortical margin, and fiber-specific degeneration in neurodegenerative pathology. In sum, the approach can reveal complex intravoxel tissue structure previously thought to be beyond the scope of diffusion imaging methodology.
by David Solomon Tuch.
Ph.D.
24
Prince, Colin Darrington. "Information technology in a complex economy : the African oil and gas industry." Thesis, Cape Peninisula University of Technology, 2015. http://hdl.handle.net/20.500.11838/2284.
Full textAbstract:
Thesis (DTech (Information Technology))--Cape Peninsula University of Technology, 2015.The energy sector is fast nearing a tipping point of no turning back. Transitioning from fossil fuel to renewable energy holds both threats and opportunities for businesses across the world. Africa is a continent rich in natural resources. The World Bank predicts that by 2020 only four or five African countries will not be involved in mineral exploitation. However, the continent is in economic, political and social crises with the majority of Africans living in poverty. As an enabler of business, business expects information technology (IT) to support, grow and maintain their existing portfolio of IT products and services while at the same time innovate and build new IT competencies to respond rapidly to the transition towards renewable energy. But, IT leadership is blamed for being rigid and unable to service the evolving needs of their organisations. As a result, traditional management theory is failing IT leadership in responding to the rapid rate of change required for serving as an enabler and transformational agent for business in leveraging technology to create a competitive advantage. As an enabler of business, the rate of implementing new products and services has a direct impact on organisational competitiveness, something that traditional management theory does not provide for. Theory tells us what technical skills the IT department requires; it does not tell us what people skills are required. In addition, business managers in Africa need to develop the ability to integrate traditional and conventional management styles to resolve the unique challenges they face. The implementation of an effective and efficient IT department remains problematic for business and IT management as traditional management theory does not necessarily support the implementation of IT within organisations in the African Oil and Gas industry. This research explores the disconnect between traditional management theory and the way that IT implementation works within the African Oil and Gas industry. The study followed an inductive research approach. The research paradigm fluctuated between exploratory humanism and interpretivism. The African Oil and Gas industry presents the case study. A multistage mixed-model research design (a subset of mixed method research) was followed, combining quantitative data with qualitative data in order to add depth to the findings. The multistage mixed-model research design allowed for the collection and corroboration of data and enhanced the credibility of the study. This design was used to expand the qualitative and quantitative data collected by challenging the results from both methods.
25
Irwin, Susan M. "Emotional intelligence competencies experienced in managing complex technology projects| An exploratory study." Thesis, Capella University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10239519.
Full textAbstract:
Increased globalization and competition have forced companies to implement solutions at a rapid pace using new and evolving technology. As a result, companies are now initiating an increasing number of complex projects each year. Project management (PM) practitioners – the individuals responsible for leading a project team through the planning and implementation of these complex projects – need to understand the tools and techniques to implement a complex project successfully to meet the strategic goals of the organization. Emotional intelligence (EI) is a primary component of the leadership skills necessary to manage a complex project. The purpose of this study was to explore the EI competencies used by PM practitioners who managed a complex project as defined by Qureshi and Kang (2015). Using the Goleman model of EI, this study investigated 22 PM practitioners who managed a complex project and found the PM practitioner’s ability to be adaptable, innovative, and trustworthy to be key personal competencies used in the management of a complex project. Furthermore, the ability to understand organizational politics and its effect on the team and the complex project, to maneuver around it, and to be influential, and deal with conflict are necessary social competencies when managing a complex project. These competencies are not limited to complex projects. This study also investigated EI competencies experienced in non-complex projects and found that trust, conflict management, influence, and political awareness were all EI competencies that held equal importance to PM practitioners when managing a non-complex project. People were the key. Findings from this study found that – although non-complex projects may not provide the innovative approaches or the need to adapt to change as found in a complex project – when people are involved, PM practitioners still need the ability to trust, resolve conflict, deal with and maneuver around the political climate, and influence the team.
26
Collin, Imad. "Visualizing Complex Systems : Variability in E/E Architecture." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-396458.
Full textAbstract:
Scania builds complex products (trucks and busses) from many different parts which must be combined according to particular rules. These rules have to be considered when building the Electrical and/or Electronic system (E/E) architecture of a vehicle. At Scania, the E/E architecture is a combination of Electrical Control Units (ECU) s, Actuators, and Sensors. This architecture is visualized using graph layouts and because of the complexity and the difficulty of reading and understanding such systems, it is essential to choose the right adapted visualization algorithms to the problem domain. For instance, the generated E/E diagrams in many cases are hard to understand, and see the entities and the relations between them. Moreover, in some case there is duplication or reused parts showed. Hence, the diagrams become more complicated to see how different parts interact with each other. Similarly, finding creative solutions to visualize different levels of granularity of the system (high level and low level) is a challenge. All of these challenges require an extensive investigation of how to build simple, readable, and interactive diagrams which simplify the E/E architectures in a way that is easier to understand. This degree project explores different techniques for complex systems, visualization, with the aims to give a comprehensive account of the variability problems raised at Scania. It is also considering a case study for adapting variability issues raised at Scania by concentrating on E/E architecture variability limited to two aspects, Time and Configuration. Moreover, finding creative solutions to visualize different levels of granularity of the system (high level and low level). Besides, it discusses different techniques for making an interactive diagram where the user can interact with such systems in an efficient way that increases the readability, understand-ability, and user satisfaction. In this work, the complex system E/E architecture visualization is well studied with a focus on the literature review as a core method. Similarly, different interactive techniques examined as hypotheses intending to resolve the presented problem. On the other hand, the Iterative design process is carried out to represent the proposed system. Finally, the results of this study, describe how visualization improves the readability of complex systems (E/E architecture) alongside it aims to prove how different interactive techniques enhance the readability and help to simplify complex systems which significantly impacts the users’ satisfaction.
27
Backman, Anton. "Motion prediction of ego vehicle in complex scenarios." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-278497.
Full textAbstract:
In this thesis, we study the trajectory prediction problem of an ego vehicle,i.e. "predicting" the location of the ego vehicle in the short future. Instead oftraditional methods, we use Machine Learning (ML) techniques since they easilyincorporate features, such as contextual information from the environment, theprediction process The contextual features signicantly improve the predictionquality since they provide important information about the driving environmentand scenarios.The Long Short-Term Memory (LSTM) model is used to develop variouspredictors which utilize dierent features. The predictors are evaluated againsta Zero-order hold (ZOH) model as a baseline. All models are evaluated ona complete test data set as well as specic, complex, test cases. The resultsshow that the proposed predictors generally outperform the ZOH model. Furthermore,the Root Mean Square Error (RMSE) is halved in many complexscenarios, suggesting more reliable predictions.Detta examensarbete handlar om att tackla problemet med att prediktera bratrajektorier av egofordonet, det vill säga att ”gissa” vart egofordonet kommer attåka i nära framtiden. Genom att använda maskininlärning istället för att göra modeller på det traditionella sättet så har det blivit enklare att använda andra kännetäcken, såsom kontextuell information från omgivningen, i modellerna. Dessa kännetäcken hjälper modellerna att göra bra prediktioner eftersom de ger ledtrådar om vilken situation egofordonet är i. Maskininlärning kan också vara det bättre alternativet eftersom maskininlärningsmodeller kan potentiellt se mönster som de traditionella metoderna inte kan se.LSTM modeller som använder olika kännetäcken har skapats. Dessa har evaluerats för att undersöka vilka kännetäcken som, till synes, verkar vara de viktigaste för prediktionerna. Modellerna har ställts mot en nollte ordningens model som är satt som en baslinje. Alla modeller har evaluerats på ett helt test dataset. De har också blivit evaluerade på specfika, komplexa, testfall. Resultaten visar att de förslagna modellerna är generellt bättre än nollte ordningens modellen samt att maskininlärningmodellernas RMSE är halverad i många kom-plexa testfall, vilket antyder en förbättring.
28
Fält, Susann. "Analysis of global gene expression in complex biological systems using microarray technology /." Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-612-3/.
Full text
29
Donnelly, Richard J. (Richard John) 1964, and Philip G. 1948 Potts. "Comparative study of knowledge transfer during technology pull in complex production environments." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9833.
Full textAbstract:
Thesis (S.M.M.O.T.)--Massachusetts Institute of Technology, Sloan School of Management, 1998.Vitae.
Includes bibliographical references (leaves 80-81).
by Richard J. Donnelly and Philip G. Potts.
S.M.M.O.T.
30
Yin, Xin. "Operational security monitoring technology and cooperative control principles for complex industrial processes." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/operational-security-monitoring-technology-and-cooperative-control-principles-for-complex-industrial-processes(ee55c32d-3d72-4ced-82e5-7050852dda63).html.
Full textAbstract:
The development of modern process industries, and increasingly fierce competition in the world market, has inevitably led to new demands on process control from industrial sectors. An important question for process control is how to secure the security operation of complex industries. The power system is one of the most complex industrial systems in the world, and faults in transmission lines pose a threat to the safe and stable operation of power systems. An inspection and monitoring system for transmission lines is proposed in this thesis, and, as a case study, a comprehensive early-warning scheme for assessing the icing condition of transmission lines with probability density function (PDF) based image recognition technology is carried out. In addition, fault location technologies for both transmission lines and distribution networks are discussed as another important component of the operational security of power systems. These provide fault location methods based on distribution characteristics of faulty currents in optical ground wire (OPGW) and the travelling wave scheme with distribution generations. Finally, control algorithms for optimising the power distribution network are also discussed. Cooperative control, based upon physical network connectivity, is proposed. This is used to maintain a group of generators operating at the identical ratio in terms of their available power, which is known as fair utilisation.
31
Wellbrink, Joerg C. G. "Modeling reduced human performance as a complex adaptive system." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03sep%5FWellbrink%5FPhD.pdf.
Full text
32
Weller, Peter Richard. "Intelligent monitoring of a complex, non-linear system using artificial neural networks." Thesis, City University London, 1997. http://openaccess.city.ac.uk/8386/.
Full textAbstract:
This project uses advanced modelling techniques to produce a design for a computer based advisory system for the operator of a critical, complex, non-linear system, typified by a nuclear reactor. When such systems are in fault the operator has to promptly assess the problem and commence remedial action. Additional accurate and rapid information to assist in this task would clearly be of benefit. The proposed advisory system consists of two main elements. The plant state is determined and then the future condition predicted. These two components are linked by a common data flow. The diagnosed condition is also used as input for the predictive section. Artificial Neural Networks (ANNs) are used to perform both diagnosis and predictions. An ANN, a simplified model of the brain, can be trained to classify a set of known inputs. It can then classify unknown inputs The predictive element is first investigated. The number of conditions that can be predicted by a single ANN is identified as a key factor. Two distinct solutions are considered. The first uses the important features of the fault to determine an empirical relationship for combining transients. The second uses ANNs to model a range of system transients. A simple model is developed and refined to represent an important section of a nuclear reactor. The results show good predicted values for a extensive range of fault scenarios. The second approachis selected for implementation in the advisory system. The diagnostic element is explored using a set of key transients. A series of ANNs for diagnosing these conditions are developed using a range of strategies. The optimum combination was selected for implementation in the advisory system. The key plant variables which contributed most to the ANN inputs were identified. An implementation of the advisory system is described. The system should be a single suite of programs with the predictive and diagnostic sections supported by a controller module for organising information. The project concludes that the construction of such a system is possible with the latest technologies.
33
Nelson, Sandra L. "The complex interplay of composing, developing musicianship and technology: A multiple case study." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3256395.
Full text
34
Dahlgren, Andreas. "Analysis of Complex Genetic Traits in Population Cohorts using High-throughput Genotyping Technology." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Universitetsbiblioteket [distributör], 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8291.
Full text
35
Boyles, Kyle Dean. "Exploring Critical Success Factors for Managing Complex Information Technology Projects in Federal Agencies." ScholarWorks, 2015. https://scholarworks.waldenu.edu/dissertations/1435.
Full textAbstract:
The problem addressed in this study was the lack of understanding about failures of government leadership in accomplishing complex information technology (IT) projects and the ways such failures can negatively affect organizational performance. The purpose was to query subject matter experts and leaders with the intent to identify methods to reduce complex IT project failure rates in government organizations. This qualitative study drew on the technology acceptance model and the capability maturity model integration framework to evaluate organizations' abilities to manage complex IT projects. The research questions focused on exploring senior managers' experiences, the tacit knowledge of project management methodologies, and IT governance frameworks. The Delphi method was suitable for collecting and analyzing opinions of subject matter experts to help reach group consensus. Qualitative data analysis was used to identify themes, categories, and subcategories for thematic analysis. The result of the study was the identification of critical success factors and leadership attributes to increase the success rate of complex IT projects in federal agencies. This research may be beneficial to federal government program leaders who, as the result of increased insights and knowledge, can more effectively provide online government services using technology-enabled end-users' computing devices in a cost-effective and secure method.
36
Oosthuizen, Rudolph. "Modelling methodology for assessing the impact of new technology on complex sociotechnical systems." Thesis, University of Pretoria, 2014. http://hdl.handle.net/2263/45924.
Full textAbstract:
Developing complex sociotechnical systems often involves integrating new technology into existing systems by applying systems engineering processes. This requires an understanding of the problem space and the possible impact of the new technology. Systems engineering uses modelling to explore the structural, functional, and operational elements of the problem and solution space (Hitchins 2008). Historically, systems engineering has however struggled with complex sociotechnical systems projects, as it cannot cope with the dynamic behaviour of complex sociotechnical systems.
The hypothesis of this thesis is that addressing the contribution of humans performing work in a complex, constrained and dynamic environment using modelling will result in a better understanding in the analysis phase; it should also lead to improved requirements, designs, selection of technologies, and implementation strategies, enabling sociotechnical systems to cope with complex operating environments.
A sociotechnical system consists of humans applying technology to perform work through processes within a social structure (organisation) aimed at achieving a defined objective (Bostrom & Heinen 1977, Walker et al. 2009). Work can become complex due to non-linear and dynamic interaction among the people themselves, among people and technology, as well as among people and the environment. Complexity may lead to “wicked and messy” problems, as many unintended or unpredicted consequences may be experienced. The new technology may also lead to new task possibilities that evolve user requirements (Carroll & Rosson 1992).
Systems engineering, as developed in the 1950s, forms the basis of developing systems, including sociotechnical systems. Classic systems engineering processes assume that problems can be isolated and decomposed, making the development of complex sociotechnical systems difficult. One way to improve the success of systems engineering is to ensure that the problem to be solved is properly understood. Analysis of the problem and solution space involves capturing and modelling the knowledge and mental models of the stakeholders, to support understanding the system’s requirements. A good description of the problem situation through a model is the first step towards designing and developing a solution.
The aim of this study is to develop and demonstrate a modelling methodology for complex sociotechnical systems, in support of the systems engineering process. The two approaches used in the modelling methodology are cognitive work analysis and system dynamics. Cognitive work analysis is a framework for analysing the way people perform work in an organisation, while taking the environmental constraints into consideration. The outputs of cognitive work analysis are constructs or models that capture the structure of the problem. Functions provided by different technological elements are linked to the functional requirements of the system, to achieve its purpose (Lintern 2012). However, cognitive work analysis is limited in investigating the dynamic effect of decisions and policies on the system (Cummings 2006). The dynamic behaviour of complex sociotechnical systems can be analysed using system dynamics, which uses the structure of the system in simulation. System dynamics analyse the effect of feedback and delays on operating the system, as a result of decisions based on policies (Sterman 2000).
The design science research framework, which also supports the research design of this thesis, is used to implement the modelling and structure the methodology. Design science research aims at creating technology for a human purpose, unlike the natural sciences, which are geared towards attempting to understand and define reality (March & Smith 1995). The proposed methodology is demonstrated in a case study using modelling and analysis of the impact of a new collaboration technology on command and control systems. Command and control is a good example of a complex sociotechnical system, as humans use technology to assemble and analyse information for situation assessment in support of planning operations (Walker et al. 2009). These systems are also used to control the successful implementation of plans in constrained and variable operating environments. The modelling methodology is demonstrated by modelling and assessing the effect of a new command and control technology for border safeguarding operations, anti-poaching operations and community policing forums. The new technology to be implemented in these complex sociotechnical systems is called “Cmore”. It is a web-based collaboration system that uses smartphones to capture information and track users. Even though the three demonstrations constitute similar systems, the different contextual situations result in diverse behaviour and issues to be investigated.
The demonstrations centre on the functions of situation awareness and decision support. The different output models for the command and control systems are used in system dynamics simulations to assess the effect of new technology on the operating and effectiveness of a system. The case studies demonstrated that the modelling methodology support learning about the implementation of a new technology in various complex sociotechnical systems. The developed models and constructs also supported developing evaluation templates during the planning of experiments through identifying key issues.
The system dynamics simulations used parametric inputs to investigate the behaviour of the system. In most cases, the simulation outputs identified interesting and counter-intuitive behaviour for deeper assessment. The community policing forum case study also gathered qualitative empirical evidence on the system's behaviour, during a field experiment. The outcomes are compared with the models and simulation outputs to improve the system behavioural models. The learning and improved understanding of the complex sociotechnical system behaviour gained through the modelling methodology, demonstrated its utility.Thesis (PhD)--University of Pretoria, 2014.
tm2015
Graduate School of Technology Management (GSTM)
PhD
Unrestricted
37
Varano, Ann Cameron. "Revealing Molecular Adversaries of Human Health Using Advanced Imaging Technology." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/98626.
Full textAbstract:
Single particle electron microscopy (EM) allows us to examine the molecular world and gain insights into protein structures implicated in human disease. Visualizing the 3D architecture of the macromolecules can inform drug design and preventative care. While X-ray crystallography and NMR are able to resolve atomic structures, the methodology is better suited for smaller structures with limited flexibility. Single particle EM allows us analyze larger structures that have inherent flexibility.
Protein structures can broadly be categorized as symmetry or asymmetric. There are computational advantages when analyzing symmetrical structures. Specifically, structural information can be extrapolated from fewer vantage points. Thus, symmetrical macromolecules are an advantageous for pioneering new methodologies in single particle EM. Rotavirus double layered particles (DLPs) are large macromolecular complexes that display icosahedral symmetry. Previous studies have led to a high resolution structure of transcriptionally inactive rotavirus frozen in time. However, to more fully understand rotavirus we need to examine the structure under transcriptionally active conditions. To expand our understanding, we first evaluated these viral assemblies using cryo-EM under active and inactive conditions. We found both internal and external structural differences. Based on these findings we sought to further our understanding of these nano-machines by developing a liquid cell environment to evaluate their dynamics over time. Our research not only developed a new methodology to evaluate active particles over time, we also found that the mobility of the DLPs were directly correlated to the level of transcriptional activity.
When analyzing asymmetrical and flexible protein complexes previous studies have utilized methodologies to limit the proteins' conformational variability. While this does allow for a higher resolution structure, it limits our understanding to a specific orientation and compromises the biological insights. BRCA1 is an asymmetric protein containing a large flexible region and is important in the prevention of breast cancer. We utilize silicon nitride microchips with integrated wells and decorated with a lipid monolayer to capture and image BRCA1 complexes. This imaging platform minimizes heterogeneity and ensures the sample quality while not biasing confirmation. Thus, allowing for high resolution cryo-EM imaging of flexible native proteins. We were able to examine BRCA1 complexes from cells at both the primary and metastatic sites. Our ability to visualize these proteins in their native form provide insights into the variability of BRCA1 in disease progression. We found that BRCA1 complexes isolated from metastatic cells have additional density in the C-terminal domain. Our data suggests this density it due an interaction with p53.
Overall, our methodologies highlight the power of single particle EM for studying protein complexes. Furthermore, our findings emphasize the importance of examining protein complexes in their native state.PHD
38
Smolenska, Greta. "Complex Word Identification for Swedish." Thesis, Uppsala universitet, Institutionen för lingvistik och filologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-352349.
Full textAbstract:
Complex Word Identification (CWI) is a task of identifying complex words in text data and it is often viewed as a subtask of Automatic Text Simplification (ATS) where the main task is making a complex text simpler. The ways in which a text should be simplified depend on the target readers such as second language learners or people with reading disabilities. In this thesis, we focus on Complex Word Identification for Swedish. First, in addition to exploring existing resources, we collect a new dataset for Swedish CWI. We continue by building several classifiers of Swedish simple and complex words. We then use the findings to analyze the characteristics of lexical complexity in Swedish and English. Our method for collecting training data based on second language learning material has shown positive evaluation scores and resulted in a new dataset for Swedish CWI. Additionally, the built complex word classifiers have an accuracy at least as good as similar systems for English. Finally, the analysis of the selected features confirms the findings of previous studies and reveals some interesting characteristics of lexical complexity.
39
Blenkhorn, Daniel John. "Novel approaches to the measurement of complex atmospheric VOC mixtures using proton transfer reaction mass spectrometry." Thesis, University of Birmingham, 2019. http://etheses.bham.ac.uk//id/eprint/8695/.
Full textAbstract:
Proton Transfer Reaction - Mass Spectrometry (PTR-MS) is a soft chemical ionisation mass spectrometry technique frequently applied to measurement of volatile organic compound (VOC) abundance. The overarching aim of this thesis is to improve the quantification of compounds that have proved difficult or even impossible to separate or to quantify, through advanced understanding of the detection and ionisation mechanisms and developments in the instrumental design and operation of PTR-MS for deconvolution of mixtures. A new method for the preparation and use of diffusion tube methods as gas standards is reported. Detailed investigation of the ion-molecule reactions with chloroalkanes, chloroalkenes and other atmospherically important molecules, such as isoprene / 2-methyl-3-buten-2-ol, benzene / ethylbenzene / o,m,p-xylene and methyl vinyl ketone / methacrolein were undertaken to determine the ion- molecule reaction mechanisms, allowing quantification of isomeric species through understanding of the reaction products and novel approaches to the switching of the reduced electric field strength (E/n). The modification of instrumental parameters of PTR-MS were investigated further for the quantification of semi volatile compounds (SVOCs) and more specifically, polycyclic aromatic hydrocarbons (PAHs). Use of a radio frequency (RF) ion funnel and high temperature instrumentation allowed for sub nanogram limits of detection for many PAHs, including Benzo[a]pyrene.
40
Li, Feng. "Integrated tactile-optical coordinate measurement for the reverse engineering of complex geometry." Thesis, University of Huddersfield, 2014. http://eprints.hud.ac.uk/id/eprint/23725/.
Full textAbstract:
Complex design specifications and tighter tolerances are increasingly required in modern engineering applications, either for functional or aesthetic demands. Multiple sensors are therefore exploited to achieve both holistic measurement information and improved reliability or reduced uncertainty of measurement data. Multi-sensor integration systems can combine data from several information sources (sensors) into a common representational format in order that the measurement evaluation can benefit from all available sensor information and data. This means a multi-sensor system is able to provide more efficient solutions and better performances than a single sensor based system. This thesis develops a compensation approach for reverse engineering applications based on the hybrid tactile-optical multi-sensor system. In the multi-sensor integration system, each individual sensor should be configured to its optimum for satisfactory measurement results. All the data measured from different equipment have to be precisely integrated into a common coordinate system. To solve this problem, this thesis proposes an accurate and flexible method to unify the coordinates of optical and tactile sensors for reverse engineering. A sphere-plate artefact with nine spheres is created and a set of routines are developed for data integration of a multi-sensor system. Experimental results prove that this novel centroid approach is more accurate than the traditional method. Thus, data sampled by different measuring devices, irrespective of their location can be accurately unified. This thesis describes a competitive integration for reverse engineering applications where the point cloud data scanned by the fast optical sensor is compensated and corrected by the slower, but more accurate tactile probe measurement to improve its overall accuracy. A new competitive approach for rapid and accurate reverse engineering of geometric features from multi-sensor systems based on a geometric algebra approach is proposed and a set of programs based on the MATLAB platform has been generated for the verification of the proposed method. After data fusion, the measurement efficiency is improved 90% in comparison to the tactile method and the accuracy of the reconstructed geometric model is improved from 45 micrometres to 7 micrometres in comparison to the optical method, which are validated by case study.
41
McLaughlin, Anne Collins. "Attentional demands on input devices in a complex task." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/30305.
Full text
42
Aoyama, Teruyoshi. "Improvement of technology for non-viral gene delivery system using DNA-cationized gelatin complex." Kyoto University, 2003. http://hdl.handle.net/2433/148731.
Full text
43
Sjöberg, Astrid Selling. "Willing Technology : Inheriting understanding and practice in an complex technological system of dialysis treatment." Thesis, Blekinge Tekniska Högskola, Avdelningen för för interaktion och systemdesign, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-2997.
Full textAbstract:
This thesis was originally motivated by a curiosity about how historicity and culture forms understanding in activities in a work situation. I wanted to gather and structure some thoughts about what happens when scientific, formally educated, knowledge, which dominates in a traditional desk learning situation, is facing knowledge which is learned through practice in real work situations with complex technology. These contradictions, I believe, must be something we all experience every day, more or less consciously. A study could perhaps be done at any kind of activity or work. I chose a dialysis department and the work of dialysis nurses as an example. This turned out to be a good choice, since these two perspectives of understanding becomes quite clear in a setting with new technology, which, together with routines and treatment, is developing and changing constantly. Patients, nurses, doctors, patient wards, dialysis machines, water cleansing system, and so forth create a complex system. It is not possible to analyse this system, or even create anything meaningful for it, unless bringing in a perspective of time and culture, into the discussion. Historicity explains and forms work practice at the very same time, when the nurses have to create a standpoint and an understanding for the actions they have to take. Creating meaningful design into complex environments is not helped by aiming for a total understanding of the whole system. Instead, agents that form the change of understanding, behaviour and action may work as keys into the creation of new design.
44
Meenakshi, Sundaram Vignesh. "Developing Bleeding-edge microservice solutions for complex problems : Non-intrusive technology in Walking Meetings." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-214670.
Full textAbstract:
The last decade has seen an emergence of various types of cloud services and development frameworks offered by leading companies in the software industry. While each of these services has been used to solve specific tasks, their specifications have changed over time as they have matured. Therefore, integrating these components to solve a whole new task tends to get tricky due to their incompatible and experimental nature. While some technology components might continue to be developed, others might deprecate. In this thesis, using a user-centered design and agile development approach, we have attempted to develop a cloud solution using microservice software architecture by integrating state-of-the-art technology components to solve a totally new task of providing a non-intrusive technology experience during walking meetings. We present our results based on interaction with the research group, user studies as a part of the research study “Movement of the mind”, and expectations of the working prototype within the context of walking meetings. We also present the features of the prototype and our motivation for choosing the tools to develop them. Finally, we discuss the development challenges faced during our attempt and conclude whether it is plausible to integrate various components of bleeding-edge technology to solve complex real-life problems or rather wait for these technologies to mature.Under det senaste decenniet har marknaden erbjudits en mängd olika typer av molntjänster och utvecklings-ramverk framtagna av ledande företag inom mjukvaruindustrin. Dessa tjänster har ofta använts för att lösa specifika uppgifter. Olika komponenterna som ingår i dessa specifika lösningar har med tiden utvecklats ändrats allteftersom de har mognat. Att integrera dessa komponenter för att lösa en helt ny uppgift tenderar därför att bli svårt på grund av deras instabila, inkompatibla och experimentella karaktär. Medan vissa teknikkomponenter kan fortsätta att utvecklas kan andra avstanna och utgå. Vi har närmat oss detta problemområde genom agil och iterativ utveckling samt användar-centrerad design-metod. En moln-baserad lösning som bland annat integrerat bleeding-edge teknikkomponenter har utvecklats och utvärderats med syfte att ge en icke-påträngande tekniskt support för gå-möten. De resultat som här presenteras och diskuteras baseras på interaktion med forskargruppen inom projektet "Med rörelse i tankarna", användarstudier och användartesteter i fält på olika arbetsplatser där den prototyp som utvecklats sökt motsvara användarnas utryckta förväntningar på tekniskt support för gångmöten. Vi diskuterar också prototypens egenskaper och vår motivation för val av metoder för att utveckla den. Slutligen diskuterar vi de utvecklingsutmaningar vi ställdes inför under vårt försök och om det är rimligt att integrera olika bleeding-edge komponenter för att lösa komplexa verkliga problem eller huruvida man hellre bör vänta på att dessa teknologier nått en stabilare mognadsgrad.
45
Browning, Tyson R. "Modeling and analyzing cost, schedule, and performance in complex system product development." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9764.
Full textAbstract:
Thesis (Ph.D.)--Massachusetts Institute of Technology, Sloan School of Management, Technology, Management, and Policy Program, February 1999.Includes bibliographical references.
In the future, it is unlikely that complex system products will compete solely on the basis of technical performance. What will differentiate such systems and their developers is the ability to balance all the dimensions of product performance, including product pricing and timing (which are functions inclusive of development cost and cycle time). Furthermore, this balance must be congruent with customers' perceptions of value. Once this value is ascertained or approximated, complex system developers will require the capability to adjust the design process to meet these expectations. The required amount and sophistication of project planning, control, information, and flexibility is unprecedented. The primary goal of this work is a method to help managers integrate process and design information in a way that supports making decisions that yield products congruent with customer desires and strategic business goals. This work consists of three parts. Part one contains two exploratory studies that further understanding of complex system product development processes. One study explores process iteration and seeks to explain why some aircraft development programs do not address iteration with existing project planning and control methods. The other study examines sources of risk, classifying these into six categories (cost, schedule, performance, technology, business, and market risks) and building causal frameworks to represent their relationships. Both studies point to avenues for improving existing process '·models and in some cases reveal process characteristics requiring new methods. These results, while derived from projects in the aerospace industry, are highly applicable across a variety of complex system development projects. Part two entails an effort to model some of the characteristics observed in part one. After a review of four types of dependency structure matrices (DSMs), notably the activity-based or schedule DSM, extensive data are collected from an uninhabited aerial vehicle (UAV) design process. Part two thus describes how to build a DSM model and provides data for example applications of the detailed models developed in part three. Based on the foundational work of parts one and two, part three develops a new methodology and models for understanding product development process cost, schedule, and performance. The methodology complements activity-centric schedule models such as DSM in that activities provide direct contributions to process cost and schedule and design performance. This approach sets the stage for integrated cost, schedule, and performance analyses. A cost and schedule model is presented first, and it is extended to account for the effects of activities on product performance. The stochastic, simulation model generates distributions of possible cost, schedule, and performance outcomes. These distributions represent uncertainty and are analyzed in relation to impact functions and targets to determine levels of risk. The model outputs enable the exploration of the costs and benefits of several management options and yield interesting insights. The goal is to improve product development planning and control though the capability to balance cost, schedule, and performance appropriately.
by Tyson Rodgers Browning.
Ph.D.
46
Schubert, David Alan. "An Instructional Designer Competency Framework for Complex Learning Designs." Diss., NSUWorks, 2019. https://nsuworks.nova.edu/gscis_etd/1085.
Full textAbstract:
Learning design competency frameworks published by professional organizations, exist for typical instructional design efforts. However, a review of literature revealed a lack of frameworks available for the creation of complex learning designs (CLDs). The goal of this research was to develop a competency framework for the creation of CLDs. Quantitative and qualitative methods were employed in the four phases of the design and development research approach In phase one, a survey based on the Educational Technology Multimedia Competency Survey (ETMCS) was sent to instructional designers who self-reported as having experience creating CLDs. The purpose of phase one was to identify competencies that instructional designers felt were most important to the creation of complex, technology-mediated learning designs.
The preliminary CLD framework was constructed during phase two, based on analysis of the ETMCS survey results. Measures of central tendency were used to identify competencies considered essential and desirable. Additionally, competencies were categorized into seven domains In phase three, semi-structured interviews were conducted with a subset of survey participants. The purpose was to gain deeper insight into the participant’s perception of the design complexities involved with each of the competencies included in the preliminary framework. In phase four, the preliminary framework was internally validated using an expert panel employing the Delphi method to build consensus. Three rounds were required to achieve consensus on all competencies within the framework. This consensus resulted in 79 competencies including 30 essential and 49 desirable competencies from the set identified as the preliminary framework during phase two.
Several conclusions emerged from the creation of this framework. Though technology is often a trigger for many types of CLDs, specific technologies are certainly desirable, but not essential. The research also revealed that communication and collaboration competencies are almost universally essential due to the complexity of the designs which typically necessitates the formation of multi-discipline teams. Without these competencies, the team’s cross-profession effectiveness is often hindered due to differences in terminology, processes, and team member geographic location.
47
Sjöberg, Hans. "Release and transport of drugs in some complex and interacting systems /." Uppsala, Sweden : Uppsala University : Distributed by Uppsala University Library, 2000. http://w3.ub.uu.se/diss/eng/abstract.cfm?ISBN=91-554-4731-7.
Full text
48
DALLA, ROSA LEONARDO. "Structural Health of a concrete tunnel lining under complex in situ loading." Thesis, KTH, Bro- och stålbyggnad, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-255537.
Full textAbstract:
Supporting structures were designed for a utility tunnel in hard rock which was to be intersectedby some road tunnels. With the intersections involving partial overlapping between the idealcross-sections, a concrete lining and post-tensioned steel cables were added to support theutility tunnel prior to the excavation of the road tunnels. The objectives in this work wereto identify the structural behaviour of the system, assess the present state of the supportingstructures and suggest an effective monitoring strategy. Preliminary information was collectedfrom the original drawings, technical specifications as well as from site visits. Using on thefinite elements software Comsol Multiphysics, suitable models were built to represent thetunnel intersections and to test hypotheses. The significant uncertainties in the problem wereaddressed by studying limit cases and discussing their results. A measure of validation wasgained from comparing cracks in concrete on site with cracking hotspots predicted by themodel. It was concluded that the behaviour of the lining is not compatible with that of cablesuspended structures and that concrete is subject to relatively high state of stress. Monitoringcable forces was found to be an ineffective strategy for identifying changes in the structuralsystem. Monitoring the evolution of cracks in concrete was found to be the most feasiblestrategy.
49
Smith, Jenny Leigh. "The Soviet Farm Complex : industrial agriculture in a Socialist context, 1945-1965." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/40394.
Full textAbstract:
Thesis (Ph. D. in History, Anthropology, and Science, Technology and Society (HASTS))--Massachusetts Institute of Technology, Program in Science, Technology and Society, 2006.MIT Dewey Library copy issued in pages.
Includes bibliographical references (leaves 190-200).
"The Soviet Farm Complex" is a history of food, farming and the environment in the postwar Soviet Union. It tells the story of how different technical and institutional authorities created an industrial Soviet countryside in the generation after World War II. Beyond the leadership of the Soviet state, international trade relationships, new technologies, unusual scientific cultures, stubborn environmental realities and human shortcomings played important roles in shaping the progress of agricultural change. Four historical fields inform this project: the history of technology, agricultural history, Soviet history and environmental history. Each of the five chapters addresses a different time, place and theme in the history of the Soviet countryside, providing a close-up view of the most important aspects of postwar rural change. Soviet agricultural reform has often been interpreted as a failure: a textbook case of poor central planning and destructive, high-modernist logic on the part of the Soviet state. In fact, this study shows that the collective farming system as a whole was not particularly dysfunctional, nor was it doomed to failure simply by virtue of being centrally planned.
(cont.) Much like the capitalist farms with which it competed, Soviet farms struggled to overcome enormous environmental, economic and social barriers to success. Similarly to capitalist systems, the Soviet Union's farming complexes succeeded in some places, while failing spectacularly in others. The history of Soviet agricultural change is not a history of faceless state agents imposing change from a great distance. Rather, it is made up of many different kinds of people working at many different jobs. Agricultural scientists and bureaucrats performed research, wrote reports, created policies and issued orders, sometimes against their better judgment and sometimes with the full force of their beliefs behind them. On the ground, agricultural laborers tried to follow the orders that originated from these higher echelons although workers and their work often experienced periods of great transition. In the universities, teachers endeavored to instruct their students in modern and efficient methods of producing food, and in every city and village the powerful tool of Soviet propaganda strived to persuade citizens of the value and logic of all aspects of agricultural modernization.
(cont.) By examining the connections between state authority, agricultural modernization and environmental change, this dissertation shows that the industrialization of the Soviet countryside was a dynamic and convoluted process, affected far more by the seemingly trivial histories of genetic variation, animal nutrition and weather than by the machinations of powerful politicians or the mismanagement of inept bureaucrats.
by Jenny Leigh Smith.
Ph.D.in History, Anthropology, and Science, Technology and Society (HASTS
50
SABELLA, SABRINA. "Complex Modeling and Analysis of the Energy Systems in Afghanistan with OSeMOSYS." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-292933.
Full textAbstract:
This Master's Thesis aimed to use quantitative analysis to explore dierent pathways for the sustainable development of Afghanistan. The Open Source Energy Modeling System (OSeMOSYS) was adopted to build an energy model of the country. Electricity demand projections for residential, industrial and commercial sectors were created using both a bottom-up and a top-down approach. These were then used as input data for the optimisation model. Starting from the Reference scenario, three additional scenarios were elaborated: Limit Import scenario, Renewable scenario and National Policies scenario. These showed different options of the least-cost energy mix and explored fundamental aspects to be considered for sustainable development, such as grid access, energy reliability, efficiency and costs, potential of renewable energy. In detail, the Limit Import scenario restricted electricity import up to 60% by 2050. The Renewable scenario applied the following constraints of minimum RE penetration: 20% by 2020, 30% by 2030, 40% by 2040. The National Policies scenario implemented the capacity of power plants that were already planned and commissioned by the country's future plans. The results highlighted a strong dependency on import as well as a consistent fossil-fuel baseload across all scenarios. Even if the investment costs were decreasing over time, renewables would enter the mix only if strict targets were applied. Hydro power represented the only green technology to play a bigger role in the mix. Overall, the results of this study could be used as an informative source for the national policy makers.Denna masteruppsats syftade till att använda kvantitativ analys för att utforska olika vägar för en hållbar utveckling i Afghanistan. Open Source Energy Modeling System (OSeMOSYS) antogs för att bygga en energimodell av landet. Prognoser för efterfrågan på el för bostads-, industri- och kommersiella sektorer skapades med både en bottom-up och top-down-metod. Dessa användes sedan som indata för optimeringsmodellen. Från och med referensscenariot utarbetades ytterligare tre scenarier: Limit Import-scenario, Förnyelsebar scenario och Nationella Policies-scenariot. Dessa visade olika alternativ för den billigaste energimixen och undersökte grundläggande aspekter som ska beaktas för hållbar utveckling, såsom nätåtkomst, energisäkerhet, effektivitet och kostnader, potential för förnybar energi. I detalj, begränsade scenariot Limit Import elimporten upp till 60 % fram till 2050. I det förnybara scenariot tillämpades följande begränsningar av minsta möjliga REpenetration: 20 % till 2020, 30 % till 2030, 40 % till 2040. National Policies-scenariot implementerade kapaciteten hos kraftverk som redan planerades och beställdes av landets framtida planer. Resultaten visade pa ett starkt beroende av import såväl som en konsekvent basbelastning för fossila bränslen i alla scenarier. Även om investeringskostnaderna minskade över tiden skulle förnybara energikällor komma in i mixen endast om strikta mål tillämpades. Vattenkraft representerade den enda gröna tekniken som spelade en större roll i mixen. Sammantaget kan resultaten av denna studie användas som en informativ källa för de nationella beslutsfattarna.