This work presents a preliminary design of a liquid rocket engine test platform to support research into liquid propulsion systems and rocket engine components, including injectors, ignition systems, combustion chambers and engine cooling systems. The liquid propellants, specifically liquid oxygen and ethanol, are pressure-fed using gaseous nitrogen. The test platform supports engine thrust values up to 1 kN, as well as varying oxidizer/fuel ratios up to 4.0 and varying ethanol concentrations between 70 and 100%. The test platform will integrate with a mobile control centre, which was designed concurrently, and provides remote control of the test procedures and data acquisition of all relevant pressure, temperature, mass flow and thrust data. The propellant feed assembly can support both cold and hot fire testing campaigns and is equipped with numerous safety features including inert gas purge lines, emergency drain lines and emergency shut-down and de-pressurization procedures.

The purposes of this study were: (1) to determine whether there was a correlation between a quantitative assessment of postural sway , and a clinical assessment of postural stability, in patients diagnosed with idiopathic Parkinson's disease (PD); (2) to plot individual diurnal changes in postural sway characteristics of PD patients over an eight-hour time period; (3) to plot day to day changes in individual postural sway characteristics of PD patients: (4) to determine whether there was a difference in the postural sway characteristics of parkinsonians, with and without vision; (5) to determine whether there was a difference in the postural sway characteristics of the same individuals when using either Sinemet or Oeprenyl. Three male PD patients were recruited into this study. Each subject stood on a stable force platform (AMT1 OR6-5-1). Measurements included the standard deviations of the coordinates of the centre of pressure (COP) in the anterior-posterior (a-p) and lateral (lat) directions, the mean velocity of sway, and area of sway. These dependent measures were evaluated in a "quiet standing" condition, once with the eyes open (EO) and once with the eyes closed (EC). These procedures were carried out ten times over the course of an eight hour day. Each subject was tested two days while taking eight hour day. Each subject was tested two days while taking Sinemet, and two days while on the Deprenyl regimen. Secondly, at two periods of each test day, each patient was evaluated using the postural assessment section of the Sears Parkinson's Assessment Form (SPAF). The results were: (1) group analyses and individual analyses established the evidence of significant correlations between both the quantitative measures of postural sway (force platform) and the qualitative assessment tool (SPAF): (2) significant variability was evident in the analysis of individual data plots: (3) no statistically significant differences were observed tor any subject when measured from day to day; (4) generally, vision was a stabilizing factor in postural control, however, this was quite variable for each subject; (5) significant improvements in postural stability were observed with the introduction of Deprenyl for one out of three subjects. These findings are discussed in terms of their clinical and behavioral importance, with specific reference to Physiotherapy. / Thesis / Master of Science (MS)

This body of work presents methods for the optimization, analysis, and control of mixed serial-parallel structures known as SP-Stacks. A SP-Stack is a series of Stewart Platforms (SPs) linked via their top and bottom plates to create a serial chain of parallel mechanisms. SP-Stacks are unique in their bridging of the benefits of parallel architectures (high rigidity, strength, and precision) and serial architectures (reach and manipulability), at the cost of being extremely overactuated. SP-Stacks are also difficult to provide kinematic solutions for, as neither forward nor inverse kinematics of a system are closed form. The first work presented focuses on presenting algorithms and optimization functions pertaining to the kinematic configuration of a SP-Stack. It first presents two methods of fast inverse kinematics (IK) for the SP-Stack which do not take forces into account. The outputs of those more simplistic solvers as used as initial conditions for a Nonlinear Program (NLP) algorithm which optimizes the internal configuration of a SP-Stack such that the end effector (EE) plate remains at the desired location, and the maximal force experienced on any actuator is minimized. The second work presented focuses on hardware testing some of the constituent algorithms and conclusions drawn from the first paper and determining methods of compensating for, in software, detected defects in hardware and hardware measurement systems. This work also demonstrates a different form of force-optimization - compliance control (CC), which is executed on both a single SP responding to external forces, and a 2 SP-Stack responding to regular internal perturbation. Conclusions drawn from these works are useful for stacks of an arbitrary number of SPs, can be extended to other mixed-kinematic systems, and advance the capabilities of these systems to be useful contributors in field robotics. / Master of Science / A stewart platform (SP) is a type of robot which consists of two plates interconnected by six linear actuators in parallel, which allow the robot to either translate or rotate about any axis in space. SPs are limited in their ability to move, as their parallel construction limits their workspace. In order to counteract this, SPs can be stacked on top of one another, creating a SP-Stack. The SP-Stack is capable of using its status as a mixed serial-parallel system to move in a significantly larger area (an advantage derived by the serial component of its architecture) and retain extraordinary rigidity and strength (an advantage from its parallel architecture). As each SP has 6 Degrees of Freedom (6DoF), enabling the previously described free-space motion, a SP-Stack possesses 6n DoF, making it overactuated. An overactuated system has multiple internal configurations which allow for a desired end effector configuration. The body of work presented herein focuses on manipulating the overactuation of SP-Stacks to achieve desirable results such as finding configurations which are most resistant to external loading (optimization of actuator forces) or algorithms which allow SP-Stacks to comply with external loading (compliance control (CC)). The first work presented herein focuses on determining an optimal configuration for a 4 SP-Stack such that the maximum force experienced by any one of its linear actuators is minimized, given a known external force. This work also presents two methods of generating initial configurations for the SP-Stack which are fed into the optimization algorithm which produces the final solution, as well as providing details on the constraints which govern the movement and validity of configurations for the system. The second work presented expands on the work done in the first, moving into hardware testing for verification of algorithms which calculate forces experienced by the linear actuators. The hardware testing showcases some errors that can be introduced by low fidelity hardware, along with methodologies for counteracting those errors. Finally, the second work introduces CC, the ability for a robot to move itself to adapt to incoming forces, and applies it to a physical 2 SP-Stack as a demonstrator.

With the advent of smart devices, Internet of things and cloud computing the amount of information collected about an individual is enormous. Using this meta-data, a complete profile about a person could be created - professional information, personal information like his/her choices, preferences, likes/dislikes etc. The concept of privacy is totally lost with this gamut of technology. The ability to separate one's on-line identity from their personal identity is near impossible. The conflicting interests of the two parties - service providers' need for authentication and the users' privacy needs - is the cause for this problem. Privacy Preserving Authentication could help solve both these problems by creating valid and anonymous identities for the users. And simply by proving the authenticity and integrity of this anonymous identity (without revealing/exposing it) the users can obtain services whilst protecting their privacy. In this thesis, I review and analyze the various types of PPA schemes leading to the discussion of our new scheme 'Lightweight Anonymous Attestation with Efficient Revocation'. Finally, the scenarios where these schemes are applicable are discussed in detail. / Master of Science / With the advent of smart devices, people are almost always connected to the Internet. These smart devices and applications collect information about the user on a massive scale. When all such meta-data are put together, a complete profile of the user - professional and personal information, his/her choices, preferences, likes/dislikes etc. could be created. And all this data is stored somewhere on the Internet. The concept of privacy loses its meaning as this entity knows more about the user than they do themselves. The main reason for this is the inability to separate one’s on-line identity from their personal identity. Service providers need to authenticate the users - the process by which one entity is assured of the identity of the second entity it is interacting with - to ensure only valid members are allowed to use their service. This leads to invasion of the user’s privacy/anonymity as authentication often needs details like address, date-of-birth, credit card details etc. Privacy Preserving Authentication could help solve both these problems by creating valid but anonymous identities for the users. PPA works by issuing the users a secret credential if they can prove their identity. And simply by proving the authenticity and integrity of these secret credentials (without revealing/exposing it) the users can obtain services whilst protecting their privacy. In this thesis, I review and analyze the various types of PPA schemes leading to the discussion of our new scheme Lightweight Anonymous Attestation with Efficient Revocation. Finally, the application scenarios where these schemes are applicable are discussed in detail.

<p dir="ltr">In recent years, Federated Learning (FL) has emerged as a promising approach for training machine learning models across distributed data sources while preserving privacy. However, traditional FL faces significant challenges in reliabilities, including the risk of the single point of failure and vulnerabilities to adversarial attacks. </p><p dir="ltr">This research proposes an innovative framework, Blockchain-based FL(BCFL), leveraging blockchain to decentralize the FL system and enhance its reliability. To optimize BCFL in resource-constrained environments, we design incentive mechanisms and resource allocation schemes to maximize computational efficiency for clients engaging in both training and mining tasks. Additionally, we introduce a dual-task resource allocation scheme specifically tailored for Mobile Edge Computing (MEC), enabling edge servers to manage both BCFL and offloading tasks efficiently. To address the inherent risk of client dropout in distributed learning, we propose the HieAvg algorithm within a decentralized hierarchical FL framework, mitigating the impact of stragglers through historical weight-based aggregation. This research also introduces the Faker attack, a novel model poisoning approach that exploits weaknesses in similarity metrics commonly used in FL defenses. In response, we develop the Similarity of Partial Parameters (SPP) defense, a random parameter selection strategy that disrupts the predictability of similarity evaluations, offering robust protection against adaptive attacks.</p><p dir="ltr">Our research provides practical strategies to fortify FL systems against reliability vulnerabilities. This work lays the foundation for more secure, reliable, and efficient FL in various environments through decentralized architectures and novel fault </p>

Asset management of force main infrastructure entails accurate prediction of the condition of the system to operate and maintain at the lowest overall costs. In this thesis report, guidelines for asset management of force main infrastructure is provided by synthesizing the trends observed in the inspection, condition assessment and renewal engineering strategies. Furthermore, this thesis focuses on development of a centralized web-based platform for advanced asset management of force main infrastructure. The key components involved in this comprehensive asset management of the force main infrastructure are data management, model implementation and information visualization. The thesis depicts various aspects involved in developing a web-based application for utilities that store, collect and analyze the data in dissimilar methods. A risk assessment model employed by a utility to prioritize the assets for renewal is demonstrated with various utilities' data. Consequently, the model is published as geo-processing services through ESRI ArcGIS Server. A visualization tool is developed for individual utilities that interacts with the geo-processing services and renders a web-based interactive map to visualize the model results. A drupal website (www.pipeid.org) is developed to support the data collection and model dissemination process. / Master of Science

Low-code is a modern approach to software development and has grown rapidly in recent years. By hiding complexity behind layers of abstraction, it allows inexperienced developers to create complex applications in a shorter amount of time. This thesis sets out to evaluate the current state of low-code as well as a few of the available low-code development platforms and how well their finished applications perform. A simple order management system was implemented in three low-code development platforms, Mendix, OutSystems, and Airtable, in order to gain experience in all of them. The platforms were then evaluated with respect to user experience and performance. The created applications load time and memory usage were measured in three different tests. It was found that there are plenty of low-code platforms that exist for different purposes, and that they all have their own learning curve depending on how flexible they aim to be. The performance of their respectively created applications is also similar to each other, with the only major differences being by design. / Low-code är en modern metod för mjukvaruutveckling och har vuxit snabbt under de senaste åren. Genom att dölja komplexitet bakom lager av abstraktion, kan oerfarna utvecklare producera komplexa applikationer på kort tid. Detta examensarbetet utvärderar den aktuella statusen för low-code, samt några av de tillgängliga low-code plattformarna och hur deras skapade applikationer presterar. Ett enkelt orderhanteringssystem implementerades på tre stycken low-code plattformar, Mendix, OutSystems och Airtable för att få olika erfarenheter. Plattformarna utvärderades sedan med avseende på användarupplevelse och prestanda. De skapade applikationernas laddningstid och minnesanvändning mättes i tre olika tester och utvärderades. Det visade sig att det finns flertalet low-code plattformar för olika ändamål. Plattformarna har olika inlärningskurva beroende på hur flexibla de är. Prestandan som uppmättes på vardera plattform när applikationen hade utvecklats visade sig vara väldigt likt sinsemellan. Den största skillnaden plattformarna emellan visade sig vara designvalen.

Yes / Care Opinion is an online feedback platform supporting patients to author stories about their care. It is not known whether authors would be willing to be involved in improving care through research. The aims of this study were to explore the views and preferences of Care Opinion authors about joining an online research community and to pilot new research community functionality. Five hundred and nine Care Opinion authors were invited to take part in an online survey in June 2019. Survey items included questions about participants' willingness to take part in research and their preferences for supporting processes. Data were analysed descriptively. Authors were invited to consent to join a research community and were asked to participate in three pilot studies. One hundred and sixty-three people consented to take part in the survey (32%). Participants indicated they would like to know the time commitment to the project (146, 90%), details about the organization carrying out the research (124, 76%) and safeguarding information (124, 76%). Over half indicated that they did not know how to get involved in healthcare research (87, 53%). Subsequently, 667 authors were invited to join the research community, 183 (27%) accepted, and three studies were matched to their expressed preferences for project attributes or organization type. Many people who leave online feedback about their experiences of healthcare are also willing to join a research community via that platform. They have strong preferences for supporting University and NHS research. Eligibility and acceptance rates to join pilot research studies varied. Further work is needed to grow the research community, increase its diversity, and create relevant and varied opportunities to support research. Four members of the Safety In Numbers patient and public involvement and engagement (PPIE) group advised about survey development. / National Institute for Health and Care Research (NIHR) Yorkshire and Humber Patient Safety Translational Research Centre (NIHR Yorkshire and Humber PSTRC)

No / Kernel P systems integrate in a coherent and elegant manner many of the features of different P system variants, successfully used for modelling various applications. In this paper, we present our initial attempt to extend the software framework developed to support kernel P systems: a formal verification tool based on the NuSMV model checker and a large scale simulation environment based on FLAME. The use of these two tools for modelling and analysis of biological systems is illustrated with a synthetic biology example.

Mobile platforms for archaeological purposes have increased in use over the last 20 years with many of the developments coming from Continental Europe. Mobile platform developments have mainly focused on one type of instrumentation, offering multiple sensors, depths of detection or frequencies. This development of mobile platforms has focused on data acquisition rates but has not considered the physical impact on the soil. The Geoscan Research Mobile Sensor Platform (MSP40) was intended to improve survey efficiency and remain a lightweight system. The platform can collect two earth resistance configurations that show directional variation of the current flow through soil. Additional sensors were integrated on to the square frame of the hand-pulled cart to record simultaneous fluxgate gradiometer data and a microtopographic surveys. Ground based geophysical investigation will always have a physical impact on a site. The MSP40 is no exception but careful selection of wheel types and the lightweight frame limit the damage compared to many mobile arrays. The MSP40 has been tested on a number of different soils at various times of the year with encouraging results; however issues with overcoming the contact resistance of electrodes remain. The continuous collection rate and combination of techniques means a slight drop in data quality is inevitable. However the increased data density, multiple-sensors and improved rate of collection offset reductions in data quality. The research has shown that the MSP40 can perform low impact rapid site assessments on 'vulnerable' sites, whilst maximising the information gained from a single traverse.