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Mathematical finite element models (FEMs) of spacecraft are relied upon for the prediction of loads experienced during launch and flight events. It is essential that the spacecraft is able to survive the launch environment without sustaining damage which could inhibit its ability to carry out its mission. Therefore, ensuring that these FEMs give a realistic representation of the physical spacecraft structural dynamics is an important task. To achieve a high level of confidence in the FEM in question, a correlation activity is conducted. This is the process of applying various metrics to compare computational results, from analysis of the FEM, with corresponding data derived from measurements taken of the physical hardware during vibration testing. Subsequently, updates are applied to the FEM where necessary to achieve an acceptable level of correlation. It is possible for spacecraft FEM correlation exercises to take a considerable amount of time and effort without necessarily achieving an appreciable improvement in the final FEM. As such, this project has been conducted to address the need to ensure that the procedures being applied are as effective and efficient as possible. Various aspects of the spacecraft FEM correlation process have been investigated separately, and interactions between the different stages in the process have also been considered. Two large, unique, scientific spacecraft have been used as example applications in order to carry out these studies. As well as making use of computational results from the spacecraft FEMs, this project has also included comparisons to the results from the corresponding base-shake sine-sweep test campaigns conducted on these structures. A number of noteworthy, and industrially beneficial, findings relating to the effectiveness of the spacecraft FEM correlation process have resulted from these studies: the most appropriate techniques of modal parameter estimation for the considered spacecraft applications have been established; the potential benefits and relative merits of different pre-test sensor placement procedures have been explored; inaccuracies introduced through the use of a commonly applied FEM reduction method have been demonstrated and a superior alternative identified. In addition, the efficiency of the correlation and update process has also been addressed. This has mainly been achieved through investigations concerning the applicability of commonly used target mode selection criteria to spacecraft applications, and the potential benefits of a less widely applied method which takes into consideration the expected loading scenarios to be experienced by the considered structures.

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In the residential demand side scheduling (RDSS), the energy consumption of home appliances should be scheduled with users' concerns satisfied and uncertain factors should be taken into account as they affect users' concerns. The operational safety of appliances is of great concern to users especially when appliances are scheduled in periods when users are not at home or are asleep. In these periods, appliances are in operation without users' monitoring. The energy consumption of manually operated appliances (MOAs) is uncertain when the energy consumption of schedulable appliances is scheduled and this uncertainty will affect users' electricity cost. The uncertainty of outdoor temperature has impact on the energy consumption scheduling of the heating, ventilation and air conditioning system which is one of the main RDSS sources, and it affects both the electricity cost and users' comfort. The appliances' operational safety is formulated based on whether users are at home and awake to monitor appliances' operations. The approach of finding the Pareto-optimal front is adopted to solve the multi-objective RDSS with the consid- eration of the operational safety of appliances. The uncertainties of MOAs and the outdoor temperature are dealt with through the robust optimization approach and the distributionally robust optimization approach, respectively. With the consideration of the operational safety of appliances and uncertainties of MOAs and the outdoor temperature, the RDSS is further improved with the electricity cost reduced and users' concerns satisfied.

Ambient wireless energy harvesting (AWEH), by means of capturing RF (radio frequency) and microwave energy from ambient and converting it to electric energy, has become an emerging technology and attracted an upsurge of research interests during the past five years. It could become a good addition to complement the existing energy harvesting technologies for such as vibration, solar and wind energies. One of the ultimate objectives of using these energy harvesting technologies is to create self-sustainable, truly standalone wireless sensor platforms and low power devices for smart home, smart cities and IoT applications, which will have a significant impact on our life in the future. However, the optimal design of a rectifying-antenna, or rectenna (as one of the vital devices for AWEH systems), is still very challenging. A number of key issues and research problems have been identified for broadband rectenna designs, such as the low conversion efficiency and strong nonlinearity under the ambient power conditions. The purpose of this thesis is to present a comprehensive study into broadband rectennas, aiming at overcoming the most challenging research problems of this topic. This thesis is comprised of three main research areas. The first area under investigation focuses on how to improve the overall power conversion efficiency of a broadband rectenna at ambient low power levels. In AWEH applications, a precise knowledge of ambient electromagnetic fields is essential. Therefore, a citywide electromagnetic field measurement campaign was conducted at Liverpool to identify the suitable frequency bands as well as the average power density at different ambient environments for AWEH. A novel broadband rectenna was designed and optimized at the ambient power levels obtained from the measurement campaign. Several novel techniques have been introduced to improve the overall conversion efficiency of the rectenna. Experimental results show that the harvested power and overall efficiency of this broadband rectenna are much higher than that of previously reported designs. This design confirms the feasibility of capturing RF energy from a typical indoor office environment for low power applications. The second area concentrates on how to reduce the nonlinear effect of broadband rectennas, since the performance of most existing rectennas can be significantly affected by the input power and load impedance variations due to this effect. Two designs are presented in this part. Page| xxi The first design is a novel six-band CP (circular-polarisation) rectenna using an improved impedance matching technique. A novel rectifier is introduced with a special matching network section to reduce the impedance mismatch caused by the load impedance variations. A miniaturized ultra-wideband CP receiving antenna is presented as well. Experimental results demonstrate that this design covers a wide frequency band (from 550 MHz to 2.5 GHz) and has constant conversion efficiency over a wide load impedance range (from 10 to 75 kΩ). The second design is an ultra-wide band rectenna using a hybrid resistance compression technique. The broadband matching network of this design is mixed with a resistance compression network to reduce the impedance variation of the rectifier. This design also demonstrates constantly high conversion efficiency and good impedance matching performance over a wide frequency band and load impedance range. The last area under investigation focuses on how to reduce the complexity of broadband rectennas. There are two designs presented in this part. In the first design, a cutting-edge technology to eliminate the need of an impedance matching network is introduced. A special broadband high impedance antenna is designed to conjugately match with the rectifier impedance directly. This design shows a very simple structure and design process. Experimental results demonstrate that this design without matching networks still achieves an excellent conversion efficiency, a good impedance matching performance and a reduced nonlinear effect. The second design is an adaptive rectenna with a wide band frequency-tunable feature. This design is also achieved without the need of impedance matching networks. The rectenna is configured with multiple output ports connected to a number of adaptive rectifier. Experiment results show that this design works well for a variety of frequencies, input powers and load impedance. Both designs show a much-simplified structure and reduced cost compared with other broadband rectenna designs. This thesis has successfully demonstrated a number of novel design methods for broadband rectennas. The most challenging issues such as the nonlinear effect and low conversion efficiency have been significantly overcome by using these presented technologies. The research and knowledge in this thesis should be of great significance to the future development of rectennas and have definitely increased the boundary of this topic to a new level.

The commercial incentives to obtain improved control of the steelmaking process in the electric arc furnace are presented and progress made in applying computer control is reviewed. The development of a mathematical model of the refining process is shown to be restricted by the complex metallurgical nature of the process and the deficiency of existing plant instrumentation. The ability of a mathematical model, evolved from theoretical considerations, to simulate accurately a limited class of operating practice is demonstrated. A compromise between complexity and implied certainty of the model is obtained by a reduction in the dimension of the model state vector and by the introduction of a white Gaussian noise process to account for the effect of the ignored states and the hypotheses on which the model is developed. Techniques recently developed for obtaining noise corrupted measurements of the carbon content and temperature of the process are investigated and the statistics of the uncertainty on these measurements is determined. The implementation of the extended Kalman filter for on-line state estimation is considered and the operation of the filter under varied conditions of uncertainty is discussed. A technique for controlling divergence of the filter algorithm is presented and the results of simulations indicate that estimates of the states can be obtained to the accuracy required for the design of a refining control strategy.

Cables are heavily used to transmit power and signals in various systems. However, due to the susceptibility of cable to conducted and radiated emissions, unintended response could be provoked in the cable, and therefore, degrade the system operation. This is referred to as the cable electromagnetic compatibility (EMC) problems. Deterministic simulations based on the nominal values of system variables are usually performed to predict the possible malfunction. However, the variables characterising the cable system are naturally random due to, e.g. manufacturing tolerance. As a result of the systemic uncertainty, the induced interference in the cable also becomes a random observable. Therefore, the statistical description of the cable interference is a more reasonable outcome for assessing the system risk. Accordingly, stochastic approaches are needed to produce the required statistical outcome. The conventional statistical approach to quantify the uncertainty of the system response is the Monte-Carlo (MC) method. However, the computational cost of the MC method could become overly expensive when dealing with a large number of random variables. Thus, the cable EMC problems in large platforms with multiple uncertainty sources cannot be efficiently solved using the MC method. Clearly, an efficient statistical approach needs to be sought to solve the challenging cable EMC problems in the real world. Very recently, the stochastic reduced order model (SROM) method was proposed in the field of mechanical engineering, and is known to have merits such as the non-intrusiveness feature and superior efficiency. Therefore, the potential of applying the SROM method for cable EMC problems is very promising, and thoroughly investigated in this thesis. This thesis presents a comprehensive study of the cable EMC problems. The contributions of this thesis are mainly twofold, comprising the investigation of cable interference caused by: (1) the conducted emission (mainly at intra-system level), and (2) the radiated emission when exposed to incident electromagnetic fields. In the case of parametric uncertainty, the statistical analysis of the induced interference is efficiently performed using the SROM method. Specifically, the first main contribution of this thesis is dedicated to the study of crosstalk phenomenon, i.e., the inference induced to a wire by nearby wires in the cable. A parametric study is performed to investigate the effect (i.e., by increasing or decreasing) of the cable configurational changes on the crosstalk variation. The result can also be used to suggest factors causing excessive crosstalk. Under the cable parametric uncertainty, the statistics of crosstalk is successfully predicted using the SROM method. The efficiency of the statistical analysis using the SROM method and its ease of implementation are clearly demonstrated, compared to the conventional MC method and another state-of-the-art statistical approach referred to as the stochastic collocation (SC) method. The sensitivity of crosstalk to different cable variables is efficiently quantified using the SROM method, and then ranked. With this ranking, the feasibility of reducing the complexity of stochastic EMC problems by ignoring weak parametric uncertainties is explored. The second significant contribution of this thesis is the efficient uncertainty quantification of the interference in the cable caused by random electromagnetic field illumination. The most complex scenario where the incident electromagnetic wave is assumed to be fully random is chosen for investigation. As a response to the random illumination, the statistics of the interference (i.e., the induced current) in the cable is efficiently obtained using the SROM method. The computational cost of the SROM method is shown to be significantly reduced by orders of magnitude, compared to those of the MC and SC methods. The result demonstrates the potential of the SROM method for the general problems of the cable system response to the random radiation field. Overall, the research presented in this thesis has successfully advanced the uncertainty propagation techniques for EMC problems, especially in the case of the cable interference. Based on the performance discussion, this thesis has also provided an in-depth knowledge about the merits and disadvantages of different stochastic methods, which helps EMC engineers perform the efficient statistical analysis for their specific problems.

Throughout the current development of video coding technologies, the main improvements are increasing the number of possible prediction directions and adding more sizes and more modes for blocks coding. However, there are no major substantial changes in video coding technology. The conventional video coding algorithms works well for video with motions of directions parallel to the image plane, but their efficiency drops for other kinds of motions, such as dolly motions. But increasing number of videos are captured by moving cameras as the video devices are becoming more diversified and lighter. Therefore, a higher efficient video coding tool has to be used to compress the video for new video technologies. In this thesis, a novel video coding tool, Global Motion Estimation using Motion Sensor (GMEMS), is proposed. Then, a series related approaches are researched and evaluated. The main target of this tool is using advanced motion sensor technology and computer graphics tools to improve and extend the traditional motion estimation and compensation method, which could finally enhance the video coding efficiency. Meanwhile, the computational complexity of motion estimation method is reduced as some differences have been compensated. Firstly, a Motion information based Coding method for Texture sequences (MCT) is proposed and evaluated using H.264/AVC standard. In this method, a motion sensor commonly-used in smart-phones is employed to get the panning motion (rotational motion). The proposed method could compensate panning motion by using frame projection using camera motion and a new reference allocation method. The experimental results demonstrate the average video coding gain is around 0.3 dB. In order to apply this method to other different types of motions for texture videos, the distance information of the object in the scene from the camera surface, i.e. depth map, has to be used according to the image projection principle. Generally, depth map contains fewer details than texture, especially for the low-resolution case. Therefore, a Motion information based Coding scheme using Frame-Skipping for Depth map sequence (MCFSD) is proposed. The experimental results show that this scheme is effective for low resolution depth map sequences, which enhances the performance by around 2.0 dB. The idea of motion information assisted coding is finally employed to both texture sequence and depth map sequence for different types of motions. A Motion information based Texture plus Depth map Coding (MTDC) scheme is proposed for 3D videos. Moreover, this scheme is applied to H.264/AVC and the last H.265/HEVC video coding standard and tested for VGA resolution and HD resolution. The results show that the proposed scheme improves the performance under all the conditions. For VGA resolution under H.264/AVC standard, the average gain is about 2.0 dB. As the last H.265/HEVC enhances the video encoding efficiency, the average gain for HD resolution under H.265/HEVC standard drops to around 0.4 dB. Another contribution of this thesis is that a software plus hardware experimental data acquisition method is designed. The proposed motion information based video coding schemes require video sequences with accurate camera motion information. However, it is difficult to find proper dataset. Therefore, an embedded hardware based experimental data acquisition platform is designed to obtain real scene video sequences, while a CG based method is used to produce HD video sequences with accurate depth map.

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