A Comprehensive Uncertainty Analysis and Method of Geometric Calibration for a Circular Scanning Airborne Lidar

This dissertation describes an automated technique for ascertaining the values of the geometric calibration parameters of an airborne lidar. A least squares approach is employed that adjusts the point cloud to a single planar surface which could be either a narrow airport runway or a dynamic sea surface. Going beyond the customary three boresight angles, the proposed adjustment can determine up to eleven calibration parameters to a precision that renders a negligible contribution to the point cloud’s positional uncertainty. Presently under development is the Coastal Zone Mapping and Imaging Lidar (CZMIL), which, unlike most contemporary systems that use oscillating mirrors to reflect the beam, will use a circular spinning prism to refract the laser in the desired direction. This departure from the traditional scanner presents the potential for internal geometric misalignments not previously experienced. Rather than relying on past calibration practices (like requiring data be acquired over a pitched-roof), a more robust method of calibration is established which does not depend on the presence of any cultural features. To develop this new method of calibration, the laser point positioning equation for this lidar was developed first. The system was then simulated in the MATLAB environment. Using these artificial datasets, the behavior of each geometric parameter was systematically manipulated, understood and calibrated, while an optimal flight strategy for the calibration acquisition was simultaneously developed. Finally, the total propagated uncertainty (TPU) of the point cloud was determined using a propagation of variances. Using this TPU module, the strength of the calibration solution was assessed. For example, four flight lines each of 20 seconds in duration contained sufficient information to determine the calibration parameters to such a degree of confidence that their contribution to the final point cloud uncertainty was only 0.012m in the horizontal and 0.002m in the vertical (1σ)

Secure Precise Clock Synchronization for Interconnected Body Area Networks

Secure time synchronization is a paramount service for wireless sensor networks (WSNs) constituted by multiple interconnected body area networks (BANs). We propose a novel approach to securely and efficiently synchronize nodes at BAN level and/or WSN level. Each BAN develops its own notion of time. To this effect, the nodes of a BAN synchronize with their BAN controller node. Moreover, controller nodes of different BANs cooperate to agree on a WSN global and/or to transfer UTC time. To reduce the number of exchanged synchronization messages, we use an environmental-aware time prediction algorithm. The performance analysis in this paper shows that our approach exhibits very advanced security, accuracy, precision, and low-energy trade-off. For comparable precision, our proposal outstands related clock synchronization protocols in energy efficiency and risk of attacks. These results are based on computations

An Investigation of Micro and Nanomanufactured Polymer Substrates to Direct Stem Cell Response for Biomedical Applications

The rapidly advancing field of micro and nano-manufacturing is continuously offering novel advantages to existing technologies. Micro-injection molding provides a unique opportunity to create substrates capable of controlling the mechanical environment in stem cell culture in a high throughput industrially relevant manner. The modification of such polymer surfaces to match the target surface stiffness of relatively more compliant biological tissues necessitates the movement towards higher aspect ratio smaller dimension features. The requirements provide a significant manufacturing challenge which is approaching a solution. The development of high aspect ratio large feature density polymer microarrays requires the synergistic optimization of design, material, mold tooling, and processing. A conventional mold base with steel inserts and controllable resistance heating was assembled to incorporate interchangeable inserts with microfeatured silicon inlays. Ultraviolet (UV) lithography with dry etching was used to impart microfeatures into silicon wafers with a variety of different geometries containing aspect ratios ranging from 0.92 to 6. Multiple polymer resins, including polystyrene (HIPS, PS), low density polyethylene (LDPE), cyclic olefin copolymer (COC), and thermoplastic polyurethane (TPU), were used to test replication and cellular response to materials with different bulk stiffness and topography-modified surface stiffness. The maximum achieved microfeature aspect ratio was 9.3 (high impact polystyrene), owed to tensile stretching during part ejection. For non-stretched substrates, the maximum molded aspect ratio was 4.5 (LDPE) and highest replication quotient (RQ = feature height / tooling feature depth) was 0.97 (COC). The maximum aspect ratio molded with consistent features across the entire surface was 2.1 (TPU).Parameters shown to enhance replication were mold temperature (Tmold = Tg was a critical replication transition point), injection velocity at higher mold temperatures, holding time, holding pressure, and nozzle temperature. The importance of certain parameters was material dependent, but mold temperature consistently had a relatively large impact.A concern that was addressed for a high density array of microfeatures was the consistency of replication, which is vital for the intended application and seldom address in published literature. Increased consistency was attained through strategic placement of temperature control, modification of the main cavity design, and optimized silicon tooling with reduced microcavity nanoroughness.Silicon tooling was fabricated with the initial objective being to achieve high aspect ratio negative features. However, with the realization of molding and demolding limitations, the tooling microfeature profiles were altered to include a taper and reduction of sidewall scalloping. Sophisticated methods of dry etching were used, in which a novel etching technique known as passivation compensation, was utilized to manufacture microchannels containing low levels of roughness, a well-controlled tapered profile, and the prospect of high aspect ratios. With the new tooling, topography consistency was dramatically enhanced for both COC and TPU, with Taguchi orthogonal array optimization leading to RQs of 0.82 (aspect ratio = 2) and 0.85 (aspect ratio = 2.1), respectively.Water contact angle (WCA) measurements for both COC and TPU generally increased with an increase in surface roughness (dictated by microfeature dimensions), reaching WCA measurements of 139.8o and 141.1o, respectively. WCA hysteresis appeared to increase with roughness up to a critical value for COC while continuing to increase for TPU with a transition, which is thought to be the result of material properties. Moreover, hydrophobic surfaces containing high levels of hysteresis were attributed to the petal effect associated with hierarchical surface structures. Hydrophobicity has been shown to be related to biological cell behavior, and thus is an effective characterization technique to measure interfacial properties.Simulation of the injection molding process using conventional methods was used to describe general conditions present at microchannel inlets. The sprue gate and an increase in plate thickness gave the microfeatured region additional time to fill microfeatures prior to generation of a frozen layer. The delayed solidification is attributed to the low thermal conductivity associated with the polymer melt.A cell sensing model was developed based on the mechanical interaction between cell and substrate. The model provides a useful design map by which nanofeatured polymer geometry and material choice can be made to achieve a particular apparent surface stiffness. Bending mechanics were simulated for a few specific examples, providing an indication of the limitations associated with using higher aspect ratio nanostructures. A bending example was applied to a manufactured tapered pillar to note the stiffness reduction achieved through use of the substrates molded during the current study. Cell culture studies showed that the presence of topography had a dramatic effect on cellular morphology and on stress fiber thickness, causing an increase in thickness compared to flat controls. The cytoskeletal re-arrangements occurring may be indicative of a differentiation event, and future results will indicate whether that is the case. Unconventional morphology was observed in the presence of low aspect ratio COC microtopography, ranging from alignment with the micropattern to a circular conformation where adhesion is taking place exclusively in the middle of the cell. Micromolding of tensile bars was conducted to better understand the processing effects on mechanical and thermal properties of microscale molded components. Such results could provide useful general trends for the consideration of mechanical properties of molded microfeatures being exposed to cellular mechanical traction forces, especially considering the extreme processing conditions necessary to fill increasingly small and high aspect ratio features.Results revealed that the mechanical properties of COC is largely unaffected by a wide range processing conditions, but is reduced to approximately 41% of the value obtained from traditional tensile test results. TPU showed a dramatic dependence on molding properties, with higher injection velocities and lower mold temperatures resulting in reduced elastic modulus. Simulation was used to further elucidate the cause for varying properties. Microscale elastic modulus average values approximately 31% higher compared to traditional tensile test results. Trends in thermal properties were not apparent, and were difficult to detect from relatively weak melting peaks. The use of two different polymer lots elicited drastically different results, prompting the further investigation of the differences. Crystallinity, viscosity, and chemical bond structure was found to be very different from one lot to the other.The successful fabrication of uniform tapered microfeatures with middle range aspect ratios were manufactured, and the robust mold design and the tooling fabrication method provides a blueprint for achieving higher aspect ratios with a significant level of fidelity in the future. The enhanced macro and microscale mold design, combined with a deeper understanding of processing induced mechanical thermal microscale properties, can be used to tailor the substrate bio-interface properties to the desired mechanical structure for controllable hMSC behavior

Physical sketching tools and techniques for customized sensate surfaces

Sensate surfaces are a promising avenue for enhancing human interaction with digital systems due to their inherent intuitiveness and natural user interface. Recent technological advancements have enabled sensate surfaces to surpass the constraints of conventional touchscreens by integrating them into everyday objects, creating interactive interfaces that can detect various inputs such as touch, pressure, and gestures. This allows for more natural and intuitive control of digital systems. However, prototyping interactive surfaces that are customized to users' requirements using conventional techniques remains technically challenging due to limitations in accommodating complex geometric shapes and varying sizes. Furthermore, it is crucial to consider the context in which customized surfaces are utilized, as relocating them to fabrication labs may lead to the loss of their original design context. Additionally, prototyping high-resolution sensate surfaces presents challenges due to the complex signal processing requirements involved. This thesis investigates the design and fabrication of customized sensate surfaces that meet the diverse requirements of different users and contexts. The research aims to develop novel tools and techniques that overcome the technical limitations of current methods and enable the creation of sensate surfaces that enhance human interaction with digital systems.Sensorische Oberflächen sind aufgrund ihrer inhärenten Intuitivität und natürlichen Benutzeroberfläche ein vielversprechender Ansatz, um die menschliche Interaktionmit digitalen Systemen zu verbessern. Die jüngsten technologischen Fortschritte haben es ermöglicht, dass sensorische Oberflächen die Beschränkungen herkömmlicher Touchscreens überwinden, indem sie in Alltagsgegenstände integriert werden und interaktive Schnittstellen schaffen, die diverse Eingaben wie Berührung, Druck, oder Gesten erkennen können. Dies ermöglicht eine natürlichere und intuitivere Steuerung von digitalen Systemen. Das Prototyping interaktiver Oberflächen, die mit herkömmlichen Techniken an die Bedürfnisse der Nutzer angepasst werden, bleibt jedoch eine technische Herausforderung, da komplexe geometrische Formen und variierende Größen nur begrenzt berücksichtigt werden können. Darüber hinaus ist es von entscheidender Bedeutung, den Kontext, in dem diese individuell angepassten Oberflächen verwendet werden, zu berücksichtigen, da eine Verlagerung in Fabrikations-Laboratorien zum Verlust ihres ursprünglichen Designkontextes führen kann. Zudem stellt das Prototyping hochauflösender sensorischer Oberflächen aufgrund der komplexen Anforderungen an die Signalverarbeitung eine Herausforderung dar. Diese Arbeit erforscht dasDesign und die Fabrikation individuell angepasster sensorischer Oberflächen, die den diversen Anforderungen unterschiedlicher Nutzer und Kontexte gerecht werden. Die Forschung zielt darauf ab, neuartigeWerkzeuge und Techniken zu entwickeln, die die technischen Beschränkungen derzeitigerMethoden überwinden und die Erstellung von sensorischen Oberflächen ermöglichen, die die menschliche Interaktion mit digitalen Systemen verbessern

Significance of designing the filling of an open rapid sand filter when removing impurities from water

Filtration is a mechanical process of squeezing, during which the passage of liquid occurs, in this paper, specifically water, through a porous layer of material. During that flow, the impurities are retained within that layer, which is called the filter, and the water is desired quality comes out of the filtering device. The goal of this work is to demonstrate the importance of dimensioning the filter itself, so reliably that during the actual filling of the filter, almost all impurities remain in that layer. There are different types of filters, and also different dimensions for each type. Which type will be specifically used depends on several factors such as the desired quality of the water coming out of the filter, the initial state of the water (pollution) coming into the filter, the amount of water reaching the filter, the speed of the filtration process itself, etc. In this paper, the importance of dimensioning sand filters, as well as the selection of the filter filling method, is highlighted

Significance of designing the filling of an open rapid sand filter when removing impurities from water

Filtration is a mechanical process of squeezing, during which the passage of liquid occurs, in this paper, specifically water, through a porous layer of material. During that flow, the impurities are retained within that layer, which is called the filter, and the water is desired quality comes out of the filtering device. The goal of this work is to demonstrate the importance of dimensioning the filter itself, so reliably that during the actual filling of the filter, almost all impurities remain in that layer. There are different types of filters, and also different dimensions for each type. Which type will be specifically used depends on several factors such as the desired quality of the water coming out of the filter, the initial state of the water (pollution) coming into the filter, the amount of water reaching the filter, the speed of the filtration process itself, etc. In this paper, the importance of dimensioning sand filters, as well as the selection of the filter filling method, is highlighted

Stretchable Surface Electromyography Electrode Array Based on Liquid Metal and Conductive Polymer

Electromyography (EMG), the science of detecting and interpreting muscle electrical activity, plays a crucial role in clinical diagnostics and research. It enables assessment of muscle function, detection of abnormalities, and monitoring of rehabilitation progress. However, the current use of EMG devices is primarily limited to clinical settings, preventing its potential to revolutionize personal health management. If surface electromyography (sEMG) electrodes are stretchable, arrayed, reusable and able to continuously record, their applications for personal health management are broadened. Existing electrodes lack these essential features, hampering their widespread adoption. This thesis addresses these limitations by designing an adhesive dry electrode using tannic acid, polyvinyl alcohol, and PEDOT:PSS (TPP). Through meticulous optimization, TPP electrodes offer superior stretchability and adhesiveness compared to conventional Ag/AgCl electrodes. This ensures stable and long-term skin contact for recording. Furthermore, a metal-polymer electrode array patch (MEAP) is introduced, featuring liquid metal (LM) circuits and TPP electrodes. MEAPs exhibit better conformability than current commercial arrays, resulting in higher signal quality and stable recordings, even during significant skin deformations caused by muscle movements. Manufactured using scalable screen-printing, MEAPs combine stretchable materials and array architecture for real-time monitoring of muscle stress, fatigue, and tendon displacement. They hold great promise in reducing muscle and tendon injuries and enhancing performance in both daily exercise and professional sports. In addition, a pilot study compares MEAP performance in clinical electrodiagnostics with needle electrodes, demonstrating the non-invasive advantage of MEAP by successfully recording the signals from the same motor unit as the needle. These advancements position MEAP at the forefront of the EMG field, poised to drive breakthroughs in electrodiagnostics, personalized medicine, sports science, and rehabilitation

Разработка технологического процесса изготовления вала редуктора (на анг.)

Целью выпускной квалификационной работы является разработка технологического процесса для подтверждения квалификации "бакалавр техники и технологии" по направлению 15.03.01 "Технология, оборудование и автоматизация машиностроительных производств". Выпускная квалификационная работа включает в себя проектирование технологического процесса обработки детали типа "вала редуктора" и содержит: анализ чертежа и технологичности детали; способ получения заготовки; расчет припусков на обработку; разработку технологического процесса, размерный анализ технологического процесса; выбор и расчет режимов резания; расчёт и проектирование пневматического приспособления для фрезерования шпоночной пазы с мембранной пневокамерой; расчёт времени на обработку детали для каждой операции.The purpose of final qualification paper (Diploma Thesis) is working out of a master schedule for qualification affirming "the bachelor of engineering and technique" in a major 15.03.01"Technology, the equipment and automation of engineering manufactures". Diploma Thesis includes projection of a master schedule machining a part "Shaft of reducer" and contains: the assaying of the drawing and manufacturability of the part; a choice of method of initial workpiece manufacturing; calculation of allowances in machining; master schedule working out, the dimensional analysis of the master schedule; a choice and calculation of cutting mode; calculation and design of a milling clamping levers with the membrane pneumonic chamber

Polymer Processing and Surfaces

This book focuses on fundamental and applied research on polymer processing and its effect on the final surface as the optimization of polymer surface properties results in the unique applicability of these over other materials. The development and testing of the next generation of polymeric and composite materials is of particular interest. Special attention is given to polymer surface modification, external stimuli-responsive surfaces, coatings, adhesion, polymer and composites fatigue analysis, evaluation of the surface quality and microhardness, processing parameter optimization, characterization techniques, among others

Innovation in manufacturing through digital technologies and applications: Thoughts and Reflections on Industry 4.0

The rapid pace of developments in digital technologies offers many opportunities to increase the efficiency, flexibility and sophistication of manufacturing processes; including the potential for easier customisation, lower volumes and rapid changeover of products within the same manufacturing cell or line. A number of initiatives on this theme have been proposed around the world to support national industries under names such as Industry 4.0 (Industrie 4.0 in Germany, Made-in-China in China and Made Smarter in the UK). This book presents an overview of the state of art and upcoming developments in digital technologies pertaining to manufacturing. The starting point is an introduction on Industry 4.0 and its potential for enhancing the manufacturing process. Later on moving to the design of smart (that is digitally driven) business processes which are going to rely on sensing of all relevant parameters, gathering, storing and processing the data from these sensors, using computing power and intelligence at the most appropriate points in the digital workflow including application of edge computing and parallel processing. A key component of this workflow is the application of Artificial Intelligence and particularly techniques in Machine Learning to derive actionable information from this data; be it real-time automated responses such as actuating transducers or informing human operators to follow specified standard operating procedures or providing management data for operational and strategic planning. Further consideration also needs to be given to the properties and behaviours of particular machines that are controlled and materials that are transformed during the manufacturing process and this is sometimes referred to as Operational Technology (OT) as opposed to IT. The digital capture of these properties and behaviours can then be used to define so-called Cyber Physical Systems. Given the power of these digital technologies it is of paramount importance that they operate safely and are not vulnerable to malicious interference. Industry 4.0 brings unprecedented cybersecurity challenges to manufacturing and the overall industrial sector and the case is made here that new codes of practice are needed for the combined Information Technology and Operational Technology worlds, but with a framework that should be native to Industry 4.0. Current computing technologies are also able to go in other directions than supporting the digital ‘sense to action’ process described above. One of these is to use digital technologies to enhance the ability of the human operators who are still essential within the manufacturing process. One such technology, that has recently become accessible for widespread adoption, is Augmented Reality, providing operators with real-time additional information in situ with the machines that they interact with in their workspace in a hands-free mode. Finally, two linked chapters discuss the specific application of digital technologies to High Pressure Die Casting (HDPC) of Magnesium components. Optimizing the HPDC process is a key task for increasing productivity and reducing defective parts and the first chapter provides an overview of the HPDC process with attention to the most common defects and their sources. It does this by first looking at real-time process control mechanisms, understanding the various process variables and assessing their impact on the end product quality. This understanding drives the choice of sensing methods and the associated smart digital workflow to allow real-time control and mitigation of variation in the identified variables. Also, data from this workflow can be captured and used for the design of optimised dies and associated processes