This investigation has analysed the impact on energy consumption for heating and cooling in UK housing stock, from the predicted future global warming effect, up to the 2080s. It was found that, up to the 2050s, it is likely that heating rather than cooling will remain the main source of energy use, in a pessimistic business-as-usual scenario. Micro-CHP (domestic scale combined heat and power plant) offers a medium term low carbon solution for the replacement of heating equipment. The operation of a micro-CHP unit in a time-of-use electricity tariff scenario for existing UK housing stock was simulated. The investigation analysed whether electrical export earnings could be increased by the use of feed forward control in comparison to a conventional control strategy of timed operation with optimised start, without serious compromise to fuel consumption. It has been found that the use of an auto-regressive model with exogenous input (ARX) model can adequately describe thermal characteristics of a typical house for a model based predictive controller. It was demonstrated that export earnings could be increased significantly without additional fuel consumption by accepting dynamic heating operation within a comfort range, rather than a static setpoint value. Compared to a conventional control strategy, overall CO2 emissions and peak network electricity demand were reduced. This approach increased electrical export earnings without additional fuel consumption during theoretical testing and has potential for further development. These finding confirm a positive case for utilising time-of-use electricity tariffs and could contribute significantly towards increasing the productivity of micro-CHP.

This research discusses how the design of a tornado forward error correcting channel code (FEC) sends digital data stream profiles to the receiver. The complete design was based on the Tornado channel code, binary phase shift keying (BPSK) modulation on a Gaussian channel (AWGN). The communication link was simulated by using Matlab, which shows the theoretical systems efficiency. Then the data stream was input as data to be simulated communication systems using Matlab. The purpose of this paper is to introduce the audience to a simulation technique that has been successfully used to determine how well a FEC expected to work when transferring digital data streams. The goal is to use this data to show how FEC optimizes a digital data stream to gain a better digital communications systems. The results conclude by making comparisons of different possible styles for the Tornado FEC code.

Water scarcity is a serious global issue, due to the increasing population and developing economy, and membrane technology is an essential way to address this problem. Forward osmosis (FO) is an emerging membrane process, due to its low energy consumption (not considering the draw solute regeneration). A bottleneck to advance this technology is the design of the support layer for FO membranes to minimize the internal concentration polarization. In this dissertation, we focus on the structural study and modification of the support layer for FO membranes. Firstly, we digitally reconstruct different membrane morphologies in 3D and propose a method for predicting performance in ultrafiltration operations. Membranes with analogous morphologies are later used as substrate for FO membranes. Secondly, we experimentally apply substrates with different potentially suitable morphologies as an FO support layer. We investigate their FO performance after generating a selective polyamide layer on the top, by interfacial polymerization. Among the different substrates we include standard asymmetric porous membranes prepared from homopolymers, such as polysulfone. Additionally block copolymer membrane and Anodisc alumina membrane are chosen based on their exceptional structures, with cylindrical pores at least in part. 3D digitally reconstructed porous substrates, analogous to those investigated for ultrafiltration, are then used to model the performance in FO operation. Finally, we analyze the effect of intermediate layers between the porous substrate and the interfacial polymerized layer. We investigate two materials including chitosan and hydrogel. The main results are the following. Pore-scale modeling for digital membrane generation effectively predicts the velocity profile in different layers of the membrane and the performance in UF experiments. Flow simulations confirm the advantage of finger-like substrates over sponge-like ones, when high water permeance is sought. Cylindrical pores are advantageous for mass transfer. Block copolymer substrates have cylindrical pores in the top layer and very regular pore pattern at the surface. The Anodisc alumina membrane has cylindrical pores from top to bottom. Both substrates were experimentally tested for FO application successfully. A Darcy permeability higher than 1E-20 m2 for the intermediate layer would be necessary in order to facilitate the water flow.

The objective of this dissertation is to verify and explain the forward exchange rate unbiasedness hypothesis in the foreign exchange market. Since in most of the cases the unbiasedness hypothesis fails to hold, we try to provide three different explanations of this puzzling behavior in the three essays. The first essay tries to resolve the forward premium puzzle by addressing the model misspecification issue and thereby adding a time-varying risk premium term in the percentage change specification. The risk premium term is modeled using the GARCH-M representation and the model is estimated by applying a GARCH (1, 1) specification. The second essay attributes the failure of the unbiasedness hypothesis to hold to the nonstationarity of the spot and forward exchange rate. It verifies the existence of a cointegrating relationship between the spot and the forward exchange rates and thus specifies an Error Correction Model to better capture the relation between the spot and the forward rates. Further, a cointegrating or the existence of a long run relationship between the spot and forward exchange rates and the domestic and foreign interest rates is tested. It can be viewed as a robustness check where we ensure whether the cointegrated exchange rates are still related in the long run with the inclusion of the interest rates. The objective of the third essay is to apply the generalized method of moments (GMM) to test the unbiasedness hypothesis in the foreign exchange market. Empirical evidence suggests that the spot and forward rates are nonstationary with unit roots and are cointegrated. Cointegration further suggests that the changes in the spot rate can be modeled by an Error Correction Model. The third essay explicitly derives an ECM from the levels specification and uses the GMM estimation technique to test the unbiasedness hypothesis.

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Obesity is associated with an increased risk of falls and subsequent injury. Most falls result from some type of postural perturbation. As such, it is important to understand how obesity influences balance recovery from a postural perturbation. There is limited information on the effects of obesity on balance recovery, and the limited available information is ambiguous. Therefore, the purpose of the research within this dissertation was to investigate the effects of obesity on balance recovery after a postural perturbation in young adults to better understand how obesity contributes to fall risk. Four separate studies make up this dissertation. The purpose of the first study was to investigate the effects of obesity on balance recovery ability using an ankle strategy in young adults. Normal-weight and obese participants recovered balance using an ankle strategy after three types of postural perturbations: an initial angular displacement, an initial angular velocity from the natural stance, and an initial angular velocity from a prescribed position. Obese participants were unable to recover balance using an ankle strategy as well as normal-weight participants when perturbations involved an initial angular velocity. However, no differences between obese and normal-weight participants were found when perturbations only involved an initial angular displacement. The effect of obesity on balance recovery in young adults was dependent on the perturbation characteristics, and may be explained by a possible beneficial effect of increased inertia on balance recovery after perturbations with little or no initial angular velocity. The purpose of the second study was to examine the effects of obesity on balance recovery by stepping in young adults. The ankle strategy has the benefit of simplifying the mechanics of balance recovery, but limits generalizability to more realistic fall scenarios where stepping to extend the base of support and recover balance is desired. Similar to the first study, participants attempted to recover balance following two types of postural perturbations: an initial angular displacement from an upright stance (by releasing participants from a static forward lean), and an initial angular velocity while in an upright stance (using a translating platform). In contrast to the first study, the ability to recover balance with a single-step did not differ between young normal-weight and obese adults. These results suggest that the reported increase in fall risk in obese adults is not a result of impaired balance recovery ability (at least among young adults that were tested here). The third study examined the effects of obesity on body kinematics immediately following a trip-like perturbation in young adults. Obesity was found to increase body angular velocity the perturbation, and that increases in body angular velocity were associated with an increased probability of a failed recovery. These results suggest that when a young obese and young normal-weight individual trip while walking at similar speeds, the young obese individual may be at a greater risk of falling following a trip because the young obese individual will experience a greater body angular velocity. This detrimental effect of obesity on the difficulty of recovering from a trip-like perturbation in young adults is most likely due to how mass is distributed throughout the body and not the amount of mass itself. The final study examined the relationship between relative strength and functional capability in young adults, and how obesity influences this relationship. To compare relative strength used during a functional task (i.e. balance recovery from a forward fall), the obese and normal-weight individual should complete the task with identical kinematics. Forward dynamic simulations were used to address this research question, instead of human subjects testing, to achieve identical kinematics. Differences in peak relative torques were found between the normal-weight and obese model, with the largest differences seen at the hip. These findings suggest that young obese individuals use greater relative strength at some joints than young normal-weight individuals to perform the time-critical task of balance recovery, and that these differences in relative strength demands may limit functional capability in young individuals who are obese. / Ph. D.

Tsunami is one of the most dangerous natural hazards in the coastal zone worldwide. Large tsunamis are relatively infrequent. Deposits are the only concrete evidence in the geological record with which we can determine both tsunami frequency and magnitude. Numerical modeling of sediment transport during a tsunami is important interdisciplinary research to estimate the frequency and magnitude of past events and quantitative prediction of future events. The goal of this dissertation is to develop robust, accurate, and computationally efficient models for sediment transport during a tsunami. There are two different modeling approaches (forward and inverse) to investigate sediment transport. A forward model consists of tsunami source, hydrodynamics, and sediment transport model. In this dissertation, we present one state-of-the-art forward model for Sediment TRansport In Coastal Hazard Events (STRICHE), which couples with GeoClaw and is referred to as GeoClaw-STRICHE. In an inverse model, deposit characteristics, such as grain-size distribution and thickness, are inputs to the model, and flow characteristics are outputs. We also depict one trial-and-error inverse model (TSUFLIND) and one data assimilation inverse model (TSUFLIND-EnKF) in this dissertation. All three models were validated and verified against several theoretical, experimental, and field cases. / Ph. D.

A distribution center that services value-added operations in addition to its normal operations faces a design problem: How to configure the forward/reserve departments for both of these operations. Analytical models are developed to analyze the tradeoff between floorspace and labor efficiency. Our results indicate that the best distribution center design is dependent on a company's customer demand profile as well as the relative cost of floorspace and labor. / Master of Science

The aim of this study is to investigate how teachers say they give and perceive forward-looking feedback (feedforward) on pupils’ texts in grades three and four. To collect material for this purpose, semi-structured interviews were conducted with six teachers in the early years of compulsory school. The material from the interviews was analysed with the help of the mid-range coding method. The analysis was based on the two theoretical premises for the study, the sociocultural perspective and the formative attitude. The result shows that the teachers use several methods and devices for forward-looking feedback on the pupils’ process and on their first draft. These included questioning, assignment, checklist and digital tools. The study also revealed three central aspects of the teachers’ perceptions of their forward-looking feedback: shortage of time, organizational conditions and the pupils’ maturity. In view of the current lacuna in research on forward-looking feedback in the early years of compulsory school, the results of the study can contribute to inspiring, in-depth and effective knowledge and tools for practising forward-looking feedback.

The concept of multihop communications (where the source communicates with the destination via many intermediate nodes) has been revisited and adapted to mitigate wireless channel impairments and ensure broader coverage. It has been shown in the literature that, in addition to extending coverage, overcoming shadowing and reducing the transmit power, multihop communications can increase the capacity of the network at a low additional cost. On the other hand, the problem of energy efficiency is one of the current biggest challenges towards green radio communications. Morevover, electromagnetic radiation is at its limit in many contexts, while for battery-powered devices, transmit and circuit energy consumption has to be minimized for better battery lifetime and performance. In this work, the performance of multihop communication over Nakagami-m fading is investigated for both cases without and with diversity combining. Closed form expressions of the average ergodic capacity are derived for each of these cases. Then, an expression of the outage probability is obtained using the inverse of Laplace transform and the average bit error rate is bounded using the Moment-Generating-Function approach. The energy efficiency is analyzed using the "consumption factor" as a metric, and it is derived in closed-form. And based on the obtained expressions, we propose a power allocation strategy maximizing this consumption factor.