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Flying is a safety critical activity in which the ability of the pilot to synthesise multiple sources of information, make decisions and produce appropriate control inputs is critical. Consequently, understanding and managing pilots' mental workload (MWL) is critical to flying safely and in the design of flight-decks and procedures. Investigation of objective ways to measure MWL is necessary as recent advances in sensing technology offer new opportunities to develop assessment methods that are less intrusive than existing techniques. For example, physiological methods are emerging as options for MWL assessment as they can provide in-situ measurement. These methods have potential advantages in terms of being relatively less intrusive than traditional methods, offering benefits for real workplace settings, including in the cockpit. The research presented in this thesis focuses on the exploration of MWL measurement during a simulated flying task through the investigation of factors influencing MWL during flight and the utility of using more objective methods for evaluating it. Four studies were conducted. First, acceptance of real-time mental workload monitoring was explored among pilots and passengers using a combination of interviews, surveys and online methods. A Critical Decision Method (CDM) interview was then applied to professional pilots to understand the factors that influence pilots' experiences of high mental workload during a flight. Two connected experiments were undertaken to test the utility of physiological sensors for detecting changes in mental workload during a simulated flying task. Finally, an online experiment was undertaken to evaluate vicarious estimation of workload by human observers based on videos of task performance. This combination of studies contributes to the understanding of physiological measurements of MWL during a simulated flying task. Firstly, this thesis provides insights about professionals' and public attitude towards MWL sensors technology in the future. Secondly, this thesis offers further understanding of what makes pilots experience high mental workload during landing, and it can be used as the basis for the development of a simulated flying task. Thirdly, this thesis contributes to supporting the spatial resolution of the fNIRS. More specifically, the thesis suggests that the left-side of the prefrontal cortex was activated in response to MWL changes during the simulated flying task. The notion that heart rate measures and pupil dilation can indicate MWL changes were also supported by this study. Finally, this thesis offers an initial understanding that MWL during a simulated flying task cannot be accurately predicted before the task, unless the contrasting elements of the task can be shown.

Globally, 1.4 million HIV-positive women become pregnant annually, of whom 92% reside in sub-Saharan Africa and 23% in South Africa. In 2019, 87% of HIV-positive pregnant women in sub-Saharan Africa and >97% in South Africa received lifelong antiretroviral therapy (ART) for the prevention of mother-to-child transmission (MTCT). However, the evidence regarding the association between maternal HIV/ART and perinatal outcomes has been inconsistent. This is partly due to the reliance on observational data and the use of sub-optimal methods to estimate gestational age and measure birth weight. Furthermore, the effect of maternal HIV/ART on fetal growth patterns has never been evaluated. This thesis, therefore, aimed to explore the effect of maternal HIV/ART on perinatal outcomes and fetal growth patterns. First, a systematic review and pairwise meta-analysis of observational studies was performed. Data from a prospective longitudinal study in South Africa were then analysed to assess those effects in a "real world" context. Gestational age was accurately estimated using first trimester ultrasound (<14 weeks' gestation). Fetal biometric parameters (biparietal diameter [BPD], head circumference [HC], abdominal circumference [AC] and femur length [FL]) were measured serially from 14 weeks' gestation to delivery. Birth weight was measured in a standardised manner within 24h of birth. The systematic review and meta-analysis showed that treated maternal HIV infection was associated with an increased risk of preterm birth (PTB), spontaneous PTB (sPTB), very PTB (VPTB), low birth weight (LBW) and small for gestational age (SGA) compared with HIV-negativity. However, treated maternal HIV infection was associated with a reduced risk of PTB, LBW and very LBW (VLBW) compared with untreated maternal HIV infection. Among treated HIV-positive women: 1) highly active antiretroviral therapy (HAART) was associated with PTB, LBW and SGA; 2) protease inhibitor (PI)-based ART was associated with PTB, and 3) pre-conception initiation of ART was associated with PTB and VPTB. Secondly, based on accurately determined gestational age and birth weight in the longitudinal study, the overlap between PTB and LBW was substantial, i.e. it is not worthwhile to analyse them separately. Thirdly, the multiple logistic regression showed a significant association between maternal HIV/ART and SGA and neonatal death. Risk factors for adverse perinatal outcomes were also identified: in HIV-positive women, these were dominated by nutritional factors. Lastly, the growth trajectories of fetal BPD, HC, AC and FL were similar between treated HIV-positive and HIV-negative women. Given the clear benefits of ART for improving maternal health and reducing MTCT risk, the expansion of ART coverage in women of reproductive age should be accelerated. However, the present findings of an unintended negative effect of maternal HIV/ART on perinatal outcomes highlight the importance of ongoing surveillance to assess the safety of in utero ART exposure. Accurate measurement of perinatal outcomes is essential to provide better evidence. Therefore, expansion of ultrasound access and standardised birth weight measurement within 24h of birth should be promoted, particularly in HIV-endemic settings with poor perinatal outcomes and the highest fertility rates, i.e. sub-Saharan Africa.

Sustainability-oriented innovation (SOI) has recently been generating considerable attention among researchers and practitioners. However, despite the growing attention, to date, research on SOI from the capability perspective is still under-explored. To follow up on this opportunity, this study aims to investigate the capabilities required to develop SOI at the firm-level in the Indonesian manufacturing industry. The key research questions proposed are related to, how do firms approach SOI, what barriers they face, and what specific SOI capabilities are needed to become a more sustainable innovator. Understanding existing firms’ SOI approach is crucial to provide a path to achieve sustainable competitive advantage. Awareness of SOI barriers is also critical to develop sustainable innovative practices. Both the SOI approach and SOI barriers are pivotal to identify further the specific capabilities required to be a sustainable innovator. The nature of this research is exploratory, considering the fact that the research on SOI from a capability perspective is still lacking, and very limited empirical data is available in emerging economies context. The data collection approach used is semi-structured interviews. Archival documentation and site visit are also used as other sources of data. In total, 33 semi-structured interviews were conducted involving 25 different firms with diverse characteristics in terms of industry and size. Data were analysed using radar charts and thematic analysis approaches, supported by visualisation of the thematic map and data structure technique. Indonesia is chosen as a context for this study, considering its status as a typical developing country that has a large market but faces enormous challenges in developing innovative and sustainability practices in firms. The findings of this study suggest that the majority of firms studied adopted SOI with an operational optimisation approach, and no firm is found to be following systems building approach. However, firms in different transition phases between SOI approaches were identified. The prominent SOI barriers faced by firms internally was ‘lack of resources’, while externally was ‘lack of demand’ for SOI products. The findings also suggest that firms following a more advanced SOI approach face fewer barriers than firms with a basic SOI approach. Further, there was no difference in ordinary SOI capabilities between firms that followed advanced and basic SOI approaches; however, differences were found in their dynamic SOI capabilities. Firms with higher dynamic SOI capabilities have better orientation in both innovation and sustainability as well as a better integration (Intra and inter-organisational; exploitation and exploration; manufacture and end-of-use) than firms with lower dynamic capabilities. It helps them overcome various SOI barriers and adopt SOI approach at the advanced level. This study provides noteworthy contributions to the academic literature by providing a more complete picture of SOI phenomena. It first discussing the SOI approach, then SOI barriers, and SOI capabilities. Moreover, this study also considers a balanced and holistic perspective in the analysis by involving dynamic capabilities as an overarching theoretical foundation combines with the pertinent theoretical concept in the innovation and sustainability field, including innovation management capability (IMC), natural resource-based-view (NRBV), and social resource-based-view (SRBV). The unique contributions of this study for practitioners include assisting them in understanding their SOI approach, potential SOI barriers, and specific capabilities required to develop themselves to become a more sustainable innovator. For policymakers, this study could be useful to help them in evaluating existing firms’ SOI approach as an important step to realise Indonesia’s ambition to become a more innovative and sustainable economy. The originality of this study lies in the synthesis of SOI dimensions based on the evolution of SOI literature to present as well as based on underlying theories and concepts. More specifically, this study has introduced ambidexterity as one of the SOI dimensions that have never been used before in SOI literature. This study has also provided new evidence to enhance SOI literature in the form of discovery of the transition phase between SOI approaches that did not exist in previous conceptual frameworks. Empirical data from an emerging economy has been analysed in this study, which is still under-explored in SOI literature. In the Indonesian context, this is one of the first studies to understand SOI approaches. Lastly, the capability-based perspective in this study is a follow-up to the research direction suggested in past literature in SOI, which highlights important contributions to the SOI body of knowledge.

This study outlines the role of accounting in an agencification context. It explores the everyday accounting in semi-autonomous agencies by observing micro-processes of agencification, i.e. the use of semi-autonomous agencies to deliver public services. To fully grasp how the practice unfolded in real time, ethnographic fieldwork was carried out in five agencies and one supervisory ministry in Indonesia. Participant observation was used by witnessing the ongoing processes, events, situated moments, and routines either at the collective or individual level. Data collection was supplemented by semi-structured interviews, documentary analysis, and a survey. Using practice-based views, the study unveils how everyday accountings are consequential in structuring the contours of agencification. Accounting practices constitute agencification by shaping organisational patterns and relations characterised by a high circulation of numbers and performance metrics. They contribute to the production and reproduction of agencification by actively developing its concepts, adoption, and implementation using numbers and calculative devices. Meanwhile, agencification emerges through and is constituted by the aggregation of interrelated accounting practices. It gives way to accounting-led agencies by providing more space for calculative initiatives performed by agency managers and staff to conduct and conceive their everyday tasks with reference to accounting, and use accounting to shape and pursue agencification objectives. The study suggests that practice theory enhances scholarly understanding on agencification by providing a rich analytical framework to uncover why and how accounting practices are organised. This view provides a way of understanding the various activities involved in agencification in relation to each other as several bundles of accounting activity. This further demonstrates how accounting can be studied and viewed as a social practice.

Ionic current rectification describes the unique electrochemical behaviour for devices based on microporous materials to conduct ions only in one direction under applied potential bias. The mechanism of ionic current rectification for all types of microporous materials are similar and based on electrolyte accumulation (open diode) and depletion (closed diode) within the region of a microhole in the substrate. The ionic current rectification phenomenon has been investigated for different types of ion conducting microporous materials with applications linked to future water desalination technology. In general, there are three types of microporous materials studied in the thesis that have been investigated based on (i) one-dimensional, (ii) two-dimensional, and (iii) three-dimensional pore systems. All of these microporous materials show good performance as long as semi-permeability can be achieved and maintained. In this thesis, ionic current rectification phenomena have been studied and investigated for different types of microporous materials such as, bacteriophage M13 (one-dimensional), graphene oxide and titanate nanosheets (two-dimensional), and Nafion and PIM-EA-TB “heterojunction” (three-dimensional). Each of these microporous materials gives unique electrochemical characteristics (ionic current rectification phenomena) when deposited as a film onto a poly-ethylene-terephthalate (PET) susbtrate with 20 μm diameter microhole. In the final chapter of this thesis, it is demonstrated a water desalination prototype based on ionic current rectification in microporous materials. It can be concluded that ionic diode devices based on different types of microporous materials provide a new avenue of fundamental electrochemical study with effects based on materials, device geometry, and electrolyte media. In the future, there is a possibility to develop ionic circuits and a wider range of ionic devices to provide new types of interfaces between artificial electronic systems and biological ionic systems.

Nitrogen is one of the macronutrients which is essentially required by plants. To support the precision farming, it is important to analyse nitrogen status in plants in order to prevent excessive fertilisation as well as to reduce production costs. Image-based analysis has been widely utilised to estimate nitrogen content in plants. Such research, however, is commonly conducted in a controlled environment with artificial lighting systems. This thesis proposes three novel computational intelligence systems to evaluate nitrogen status in wheat plants by analysing plant images captured on field and are subject to variation in lighting conditions. In the first proposed method, a fusion of regularised neural networks (NN) has been employed to normalise plant images based on the RGB colour of the 24-patch Macbeth colour checker. The colour normalisation results are then optimised using genetic algorithm (GA). The regularised neural network has also been effectively utilised to distinguish wheat leaves from other unwanted parts. This method gives improved results compared to the Otsu algorithm. Furthermore, several neural networks with different number of hidden layer nodes are combined using committee machines and optimised by GA to estimate nitrogen content. In the second proposed method, the utilisation of regularised NN has been replaced by deep sparse extreme learning machine (DSELM). In general the utilisation of DSELM in the three research steps is as effective as that of the developed regularised NN as proposed in the first method. However, the learning speed of DSELM is extremely faster than the regularised NN and the standard backpropagation multilayer perceptron (MLP). In the third proposed method, a novel approach has been developed to fine tune the colour normalisation based on the nutrient estimation errors and analyse the effect of genetic algorithm based global optimisation on the nitrogen estimation results. In this method, an ensemble of deep learning MLP (DL-MLP) has been employed in the three research steps, i.e. colour normalisation, image segmentation and nitrogen estimation. The performance of the three proposed methods has been compared with the intrusive SPAD meter and the results show that all the proposed methods are superior to the SPAD based estimation. The nutrient estimation errors of the proposed methods are less than 3%, while the error using the renowned SPAD meter method is 8.48%. As a comparison, nitrogen prediction using other methods, i.e. Kawashima greenness index (GIkaw) and PCA-based greenness index (GIPCA) are also calculated. The prediction errors by means of Ikaw and IPCA methods are 9.84% and 9.20%, respectively.

Despite massive global foreign reserves accumulation since the late 1990s, a study on strategic asset allocation from a central bank perspective remains relatively limited. Many countries have built up foreign reserves greater than their trading and financing sufficiency; consequently, there is increased public awareness as to how central banks manage their reserves. This research addresses the issue of asset structure of foreign reserves portfolios; currency composition and strategic asset allocation. This thesis provides an alternative strategic asset allocation framework that focuses more on liquidity and safety objectives, without sacrificing return objective of the existing central banks’ portfolios. This research contributes to the theoretical literature that combines mean-variance Bayesian framework with the spirit of the transaction theory of central bank foreign reserves. First, using the unconditional Bayesian approach with external transaction constraints, I investigate risk reduction benefits to both minimum variance and optimal portfolios for a given existing return for central banks’currency allocation. Our results show that before imposing currency weight constraints, all the diversification strategies considered provide significant benefits, regardless of the current benchmark used. The results when the trade constraints and debt constraints are imposed reveal that there is the potential for diversification benefits to be obtained from the currency portfolio optimisation. However, the choice of the current benchmark, and both trade and debt constraints, play an important role in the decision as to with which diversification strategy central bank reserves managers should proceed. Second, using the similar objective functions and diversification benefits measures, the framework is then applied to define asset allocation policy for government bond portfolio. The results from the optimal portfolio for a given existing benchmark return show that there is significant risk minimization benefit by adding developed market longer maturity, quasi-government, emerging and inflation-linked government bonds altogether to the current benchmark portfolio. The benefits could not be found if each asset class is added directly to the current portfolio policy. From the same spanning strategies as the optimum portfolio, the global minimum variance portfolio analysis shows that the diversification benefits are mainly driven by United States Treasury Bills. Third, I investigate risks minimization of government bonds portfolio for a given benchmark returns in various investment policies and risk preferences. This research examines the important role of budget constraints, liquidity buffer allocation, global financial crisis investment opportunities, investing in ultra-long government bond and non-bond investment. Analysis on the impact of the budget provides policy implications that central bank should not to tranche their reserves, but express liquidity requirements in the form of constraints on the portfolio optimisation framework. Investigation on the role of liquidity allocation confirms earlier findings that the risk reduction benefits are mainly driven by US Treasury Bills. The impact of global financial crisis since 2008 emphasises the need for central banks to diversify their foreign reserves benchmark beyond its current setting. We could not find benefits for the central bank to invest in ultra-long maturity government bonds. Lastly, we found that non-government bond investments provide significant benefits when it compares to the existing benchmark, and incremental benefits from the well-diversified government-related bond portfolio.

In the past few decades, the cities of Indonesia have experienced rapid development, with the transformation sometimes leading to improvements but often having a devastating impact on the urban environment. A worrying trend has been the reduction of the role of urban traditional streets in Indonesia as mixed-use and vibrant public places to become purely channels of movement, especially for car-based traffic. For this reason, this research focuses on assessing the quality of traditional streets in Indonesia and is being conducted before they disappear as a result of rapid development in urban areas. The primary aim of the research is to demonstrate the role of traditional streets in shaping the urban environment and urban public life. In this context, the research focuses on critically examining the distinctive characteristics of such streets through street quality indicators that have been developed in urban design discourses. A qualitative inquiry is chosen as the main research method with multiple case studies and a research strategy based on research questions, research knowledge, and expertise. The techniques to gain data were field observations (walk-by observations, pedestrian counts, and behavioural mapping) and in-depth interviews. The analysis procedure was a rationale-inductive method and relied on the data from the field work as the emerging information (data-led analysis). The research concludes that there are five major characteristics of traditional streets that play important roles to support urban public life; these are: the physical and visual quality of the street; traditional street as mixed-use urban space; as multi-cultural urban space; as a cultural path and public space of the city; and traditional street activities as intangible culture. The results of the study confirm the earlier findings that suggest that Asian street are vibrant places with mixed-use pavements that contribute significantly to the vibrancy of the city. This study adds to the knowledge of the potential of the traditional street in Indonesia as one of the primary urban spaces, as public space, as creative space, as cultural space, and as urban heritage that should be safeguarded and conserved for its outstanding value not only for its architectural diversity, but also for its intangible cultures. The research also recognises the important role of traditional streets in Indonesia to the contemporary city. The recognition of the integral entity of these streets including their economic, social, and the cultural life of the surrounding context have led to a better understanding in terms of research and can be part of the foundation to formulate better policy and design intervention for the future of Indonesian cities.

Background: This study assumes that while all families are unique, families share common tasks that must be fulfilled as part of their functioning and the definition of whether the family process is functional or not is specific and may be unique to the family and is dependent upon what the family perceives as being normal, while considering cycle demands, resources and socio cultural influences. Objectives: To explore the role of family functioning in chronic periodontitis. Methods: The Outer North East London (ONEL) Oral Health Needs Assessments collected data in a representative sample of 2,343 adults aged16-65 and 1,174 children 3-4 years old in 2009-10. Data were collected through home visits by trained dentists and interviewers, and included dental clinical examinations and answers to questionnaires. Family function in the domains general functioning, problem solving, communication, roles, affective responsiveness, affective involvement and behaviour control was assessed using the Family Assessment Device (FAD) Epstein et al., 1983). Chronic periodontitis was defined as having at least one interproximal site with pocket depth of 4 mm or more. Results: Chronic periodontitis was associated with family functioning in the domains general functioning (odds ratio:0.45; 95%CI: 0.25-0.84), communication (odds ratio: 0.55 95%CI: 0.30-0.98), affective involvement (odds ratio:0.56; 95%CI: 0.34-0.94), affective responsiveness (odds ratio:0.47; 95%CI: 0.26-0.81) and behaviour control (odds ratio:0.40 95%CI: 0.22-0.74) after adjustment for ethnicity and socioeconomic position (NS-SEC). However, after adjusting for oral health related behaviour (tobacco consumption and plaque score) only the domain of general functioning (odds ratio: 0.51 6 95%CI: 0.27-0.97) affective responsiveness (odds ratio 0.52; 95%CI: 0.29-0.92) and behaviour control (odds ratio 0.46; 95 CI: 0.25-0.83) remained significantly associated with chronic periodontitis. Family functioning domains general functioning, communication, affective involvement, affective responsiveness and behaviour control also potentially partially mediates the relationship between socioeconomic position and chronic periodontitis experience. Conclusion: Efficient family functioning in the domains of general functioning, affective responsiveness and behaviour control may act as protective factors against chronic periodontitis.

This thesis consists of two main elements: the analysis of field measurements of velocity and resistance in a river, undertaken over a three year period, and numerical modelling of open channel flow. An Acoustic Doppler Current Profiler (ADCP) was used to measure the spatial distribution of velocity in two cross sections of a small meandering river (River Blackwater, Hampshire) during inbank, bankfull and overbank flow conditions. The same reach of the river had been previously studied over a number of years, as well as investigated on a 1:5 scale physical model, making it possible to compare the flow structure in the river and in the physical model. A new measurement procedure and data processing methodology were developed for ADCP measurements, suitable for use in times of flood. Methods for orientating the measured velocity data and reducing the velocity fluctuations in the data, due to their instantaneous random nature, are described. The post processed data has been verified against 300s time-averaged velocity data at several locations along the cross sections, and also against ADV measurements obtained under the same flow conditions. The approach of averaging several transect data together has successfully reduced the noise in the ADCP velocity data. The field data indicates incremental rises in Ud with rising water level, while the opposite is true for the physical model data. Key similarities and differences between the secondary flow patterns in the river and model have been identified. The discharge capacity of the main river channel is significantly reduced during summer months, due to seasonal growth in vegetation, reaching a minimum in August. The gradient of the stagedischarge rating curve for summer months can be seven times larger than that for the winter months. The falling limbs of the rating curve have a higher discharge capacity than the rising limbs for summer months (June/July to October/November). An attempt was made to predict the stagedischarge relationship for overbank flow conditions using a quasi 2D RANS model, SKM (Shiono and Knight Method). SKM is shown to be capable of simulating the lateral distribution of the depthaveraged streamwise velocity in the river and physical model with reasonable accuracy, subject to appropriate choice of three calibration parameters. The research shows that the ADCP has a great potential for obtaining accurate 3D velocity data in rivers during flood events, and that the SKM is a useful modelling tool. The importance of taking into account the effect of vegetation when undertaking engineering design has been demonstrated.

Most modern highly productive poultry strains have been developed in temperate countries, with little opportunity for heat tolerance to be a selection factor. When these birds are moved to tropical or subtropical countries their egg production, egg quality, food intake and growth rate decrease at high ambient temperature. Varying reports on the effects of heat stress on egg and yolk production may be attributable to the differences of the range and duration of thermal loads employed, different bird strains, ages, diets and food intake responses. There are, however, only a few studies which attempt to explain the actual physiological mechanisms involved in the adaptation of laying hens to thermal loads, especially those relating to the changes in egg yolk precursors including vitellogenin and very low density lipoprotein (VLDL) synthesis, secretion and deposition in the oocytes. The major yolk precursors are vitellogenin, a metal binding protein, and VLDL, a specialised type of triglyceride-rich lipoprotein found in abundance in the plasma of laying hens. Both vitellogenin and VLDL are synthesised in the liver in response to oestrogen stimulation transported to the ovary and transferred and deposited into the growing oocytes by a selective mechanism. Chronic heat stress in laying hens reduces yolk size and total yolk production considerably. Any changes in yolk precursor synthesis mediating such a response may involve altered oestradiol secretion or reduced sensitivity of hepatocytes to oestrogen stimulation. Other possible mechanisms of reduced yolk accumulation include disturbances in the transport of vitellogenin in the blood stream and changes in the level of ovarian uptake of egg yolk precursors by the growing oocytes. The present project examined the changes in egg yolk precursor levels in the plasma of laying hens chronically exposed to different degrees of thermal stress (32 and 35°C with various relative humidities) and precursor uptake by the oocytes. The study also addressed the role of oestrogen in yolk precursor responses to chronic heat stress. In addition, the role of nutritional vitamin E supplementation as a strategy for alleviating the effects of heat stress has been examined. The studies have confirmed that heat stress reduces yolk and egg production concomitant with reduced circulating vitellogenin and VLDL in the plasma.

This thesis presents a study on SWATH type vessels which is directed towards the collection and use for structural design of experimental data related to motions and primary dynamic loads of such vessels. This data will be of use in the validation of a mathematical model for motion and wave load predictions recently developed at the Department. Further, experimental data on slamming will also be acquired to lay a foundation for the future development of a reliable analytical model. Design loads pertinent to SWATHs comprising the extreme primary loads, lifetime cyclic loads and local panel pressures are then built upon the former findings to be of use in structural designs, especially in the determination of initial scantlings and fatigue characterisation. Examples are given throughout on the evaluation of hypothetical SWATHs operating in the North Atlantic. The underlying theoretical formulation of SWATH ship motions is presented together with a description of a newly developed motion prediction theory. This is followed by a clarification of the procedures for conducting seakeeping tests on SWATH models. Validation of the analytical motion model by the measured data of single and tandem strut SWATH models is then presented. Subsequently, practical applications of implementing motion predictions to the assessment of SWATH operatiblity in real seaways are described. Theoretical background of SWATH primary wave loads is briefly outlined. The enhancement of the motion program MARCHS to tackle the primary load on SWATHs is described. The development of experimental data on SWATH loadings by way of seakeeping techniques is presented. Correlation of this experimental data and the theoretical assessment is made to demonstrate the validity of the mathematical model so developed. Lifetime cyclic and extreme loads required in the fatigue and ultimate strength designs, respectively, are developed by applying long- and short-term wave statistics.

Ransomware is a devastating type of malicious software that restricts a user's access to a digital asset of value, demanding a ransom in order to restore it. Ransomware attacks have only increased in popularity over the years and show no signs of abating. Moreover, the complexity and potential impact of these attacks have also increased, such that modern-day ransomware attacks are capable of bringing businesses and organisations to a standstill, with ransom demands often in excess of millions of pounds. The research presented in this thesis aims to contribute to a stronger foundation of knowledge regarding this relatively new cyberthreat through the development of several novel countermeasures. An in-depth analysis of current state-of-the-art anti-ransomware tools was conducted, through which an overall preference towards statistical and behavioural detection methods was identified. Additionally, several datasets and an analysis environment were constructed in order to identify and subsequently improve current statistical and behavioural approaches, contributing towards more effective ransomware detection. Untapped potential within statistical-based approaches to ransomware detection was clearly identified, showing that near-perfect classification rates were possible within the scope of our experiments. Despite the continual growth both in terms of frequency and sophistication of ransomware attacks, our results suggest that the significant differences in system behaviour observed during a ransomware attack are enough to identify and thwart ransomware attacks. Future work should pay particular attention to these clear fingerprints created by ransomware attacks, such that damages can largely be mitigated, alleviating the need to pay the ransom and thus toppling the underground ransomware economy.

Collaboration among stakeholders on poverty reduction programs in developing countries is part of strategic approach to combating and significantly reducing poverty numbers. The main purpose of collaboration among stakeholders or actors is to transform the power of togetherness into energising local communities to reduce poverty numbers effectively. However, the history of implementation of various poverty reduction programs shows that there has been a long succession of such programs implemented by the Indonesian government in attempts to overcome poverty problems and to achieve social justice. This history means that the Indonesian government has had many experiences attempting a pragmatic philosophy to achieve social equity, eternal peace and common welfare. This study investigates the implementation of collaboration among stakeholders as poverty reduction strategies during the decentralisation era in the Takalar and Barru districts, South Sulawesi Province, Indonesia. A case study approach was taken, utilising the Evolutionary Governance Theory (EGT) of Van Assche, Beunen and Duineveld (2014). This research assessed the argument that inadequate collaboration and collective decision making between stakeholders involved in the development process is a major reason why poverty reduction policy and implementation has failed at the provincial and local district levels. Data collection methods including semi-structured interviews, review of documents and field observation. The 70 (seventy) informants were selected based on their knowledge, involvement and responsibility in the various collaborative poverty reduction programs in both districts. This sample included government officials, members of donor organisations, NGOs activists, local leaders and the local communities. The elements of EGT (Assche, Beunen, & Duineveld, 2014) as a social system framework were adjusted and extended based on the findings of the study within the context of the local public policies. This adaptation is based on the consideration that “the roles of local leaders lead on collaboration between stakeholders on poverty reduction programs”. findings from the two Indonesian districts can be generalised to a broader population with some boundaries. However, this in-depth study of the cases contributes valuable theoretical and practical knowledge to the community. The study findings show that the local leader as a key position on the collaboration among stakeholders evolved from existing system of Social Governance throughout a process of evolutionary governance. These collaborative anti-poverty programs are demonstrated by two case studies, which involved elements of civil society such as local leaders, local community leaders, local communities, donors, and NGOs activists, whose involvement is a major factor in the sustainability of the programs. Future research requires exploration of the roles of these actors to provide a broader perspective on their roles in evolutionary governance implementation and sustainable use.

With the increased threat of ransomware and the substantial growth of the Internet of Things (IoT) market, there is significant motivation for attackers to carry out IoT-based ransomware campaigns. In this thesis, the viability of such malware is tested. As part of this work, various techniques that could be used by ransomware developers to attack commercial IoT devices were explored. First, methods that attackers could use to communicate with the victim were examined, such that a ransom note was able to be reliably sent to a victim. Next, the viability of using "bricking" as a method of ransom was evaluated, such that devices could be remotely disabled unless the victim makes a payment to the attacker. Research was then performed to ascertain whether it was possible to remotely gain persistence on IoT devices, which would improve the efficacy of existing ransomware methods, and provide opportunities for more advanced ransomware to be created. Finally, after successfully identifying a number of persistence techniques, the viability of privacy-invasion based ransomware was analysed. For each assessed technique, proofs of concept were developed. A range of devices -- with various intended purposes, such as routers, cameras and phones -- were used to test the viability of these proofs of concept. To test communication hijacking, devices' "channels of communication" -- such as web services and embedded screens -- were identified, then hijacked to display custom ransom notes. During the analysis of bricking-based ransomware, a working proof of concept was created, which was then able to remotely brick five IoT devices. After analysing the storage design of an assortment of IoT devices, six different persistence techniques were identified, which were then successfully tested on four devices, such that malicious filesystem modifications would be retained after the device was rebooted. When researching privacy-invasion based ransomware, several methods were created to extract information from data sources that can be commonly found on IoT devices, such as nearby WiFi signals, images from cameras, or audio from microphones. These were successfully implemented in a test environment such that ransomable data could be extracted, processed, and stored for later use to blackmail the victim. Overall, IoT-based ransomware has not only been shown to be viable but also highly damaging to both IoT devices and their users. While the use of IoT-ransomware is still very uncommon "in the wild", the techniques demonstrated within this work highlight an urgent need to improve the security of IoT devices to avoid the risk of IoT-based ransomware causing havoc in our society. Finally, during the development of these proofs of concept, a number of potential countermeasures were identified, which can be used to limit the effectiveness of the attacking techniques discovered in this PhD research.

This study performs an investigation of dynamic stall control (Gurney flap (GF)) and flow augmentation (straight upstream deflector (SUD)) devices to improve the performance of lift-driven Vertical Axis Wind Turbine (VAWT) as they can improve the power generation of VAWT at all ranges of tip speed ratios (TSRs). High-fidelity Computational Fluid Dynamics (CFD) method is applied to evaluate the performance and geometry optimisation. The accuracy and computational cost of Unsteady Reynolds Averaged Navier-Stokes (URANS) and hybrid RANS-Large Eddy Simulation (LES) turbulence models to predict the overall aerodynamic performance and flow-field characteristics of VAWT at all ranges of TSRs are compared, to identify the most suitable turbulence model with a reasonable computational cost for VAWT simulation at all ranges of TSRs. Instead of using a single parameter variation optimisation at a time, multiple parameters geometry optimisation of GF using the Taguchi method is performed to understand the correlation between evaluated geometry parameters and optimal performance. Moreover, this study evaluates geometry optimisation of GF and SUD in VAWT configuration (i.e. considering rotating effect and blade-to-blade interaction) at all ranges of TSRs, rather than evaluate a single stationary aerofoil at a single range of TSRs. Evaluation of combining GF and SUD is also delivered in this study. Additionally, 3D modifications of the Gurney flap to reduce the drag generation of VAWT with GF are evaluated to further improve the performance of VAWT.The results show that URANS turbulence models are sufficient to predict the overall performance of lift-driven VAWT and a single range of TSRs evaluation. However, Hybrid RANS-LES turbulence models are necessary to investigate the aerodynamics and flow-field characteristics of lift-driven VAWT and all ranges of TSRs evaluation. Moreover, the GF and SUD indeed can increase the performance of lift-driven VAWT at all ranges of TSRs (up to 233.19% and 139.11% at low ranges of TSRs). As the range of TSRs increases, both GF and SUD experience a decrement in the rate of Cp-ave improvement. Nevertheless, GF and SUD have different methods to improve the power generation of VAWT at each range of TSRs. Hence, it is proven that design optimisation and flow analysis of GF and SUD need to be performed at each range of TSRs. In addition, by adding the effect of rotating flow and blade-to-blade interaction, the optimum geometry design of GF is changed compared to the optimum design of a single stationary aerofoil. It confirms that design optimisation needs to be performed in a VAWT configuration (i.e., including rotating effect and blade-to-blade interaction). Noting that, combining optimised GF and optimised SUD does not increase the power generation improvement of lift-driven VAWT further. Additionally, introducing 3D modifications of GF (i.e. slits or holes) in the blades of VAWT with GF further improves the power coefficient of lift-driven VAWT. The existence of slits and holes can improve the power coefficient of VAWT with GF by 6.5%, and 0.28%, respectively.

Microfinance enables rural households to accumulate assets, smooth consumption in time of economic shocks, reduce the vulnerability due to illness, drought and crop failures, and better education, health and housing for the borrower’s household. In addition, access to finance may contribute to an improvement in the social and economic position of women participation in family decisions making. Microfinance may have positive spill-over effects such that its impact surpasses the economic and social improvement of the borrower. However, there is still concern whether microfinance performance and outreach eminently reaches the poor household. This study aims to investigate the credit accessibility and significant characteristics of rural households who are users of microcredit loans versus non-users of microcredit loans. The study also surveys the welfare impact of microfinance on rural households in Indonesia. The study administered a structured questionnaire to 605 rural households in Bantul District, Yogyakarta Province in Indonesia. Binary Logistic regression is used to investigate credit accessibility of the surveyed respondents. The results reveal that age of borrowers, household income, interest rates, and loan duration are key determinants affecting credit accessibility in the surveyed area. Similarly, binary logistic regression is used to investigate characteristics of the surveyed respondents, based upon whether they used or did not use microcredit. The empirical results suggest that age, marital status and education attainment siginificantly affect characterics of clients and non-clients of microfinance. The multinomial logit model (MNL) is used to assess the welfare impacts of microcredit in term of households income, monthly expenditure and total assets of borrowers. In term of the borrowers income, the MNL shows that age of borrowers, monthly expenditure and occupation are significant factors influencing the increase in income of the borrowers after they have accessed microcredit. In term of borrower’s total assets, the MNL model reveals that more highly educated borrowers are more likely to increase their total assets after accessing microcredit. The MNL model also reveals that only expenditure per month of borrowers has a positive correlation with the increase of welfare impacts of the clients’ expenditures.

The driving force behind research in alternative clean and renewable energy has been the desire to reduce emissions and dependence on fossil fuels. In the United States, ground vehicles account for 30% of total carbon emission, and significantly contribute to other harmful emissions. This issue causes environmental concerns and threat to human health. On the other hand, the demand on fossil fuel grows with the increasing energy consumption worldwide. Particularly in the United States of America, transportation absorbs 75% of this energy source. There is an urgent need to reduce the transportation dependence on fossil fuel for the purpose of national security. Polymer electrolyte membrane (PEM) fuel cells are strong potential candidates to replace the traditional combustion engines. Even though research effort has transferred the fuel cell technology into real‒world vehicle applications, there are still several challenges hindering the fuel cell technology commercialization, such as hydrogen supply infrastructure, cost of the fuel cell vehicles, on‒board hydrogen storage, public acceptance, and more importantly the performance, durability, and reliability of the PEM fuel cell vehicles themselves. One of the key factors that affect the fuel cell performance and life is the run‒time thermal and water management. The temperature directly affects the humidification of the fuel cell stack and plays a critical role in avoiding liquid water flooding as well as membrane dehydration which affect the performance and long term reliability. There are many models exists in the literature. However, there are still lacks of control‒oriented modeling techniques that describe the coupled heat and mass transfer dynamics, and experimental validation is rarely performed for these models. In order to establish an in‒depth understanding and enable control design to achieve optimal performance in real‒time, this research has explored modeling techniques to describe the coupled heat and mass transfer dynamics inside a PEM fuel cell. This dissertation is to report our findings on modeling the temperature dynamics of the gas and liquid flow in the porous media for the purpose of control development. The developed thermal model captures the temperature dynamics without using much computation power commonly found in CFD models. The model results agree very well with the experimental validation of a 1.5 kW fuel cell stack after calibrations. Relative gain array (RGA) was performed to investigate the coupling between inputs and outputs and to explore the possibility of using a single‒input single‒output (SISO) control scheme for this multi‒input multi‒output (MIMO) system. The RGA analyses showed that SISO control design would be effective for controlling the fuel cell stack alone. Adding auxiliary components to the fuel cell stack, such as compressor to supply the pressurized air, requires a MIMO control framework. The developed model of describing water transport in porous media improves the modeling accuracy by adding catalyst layers and utilizing an empirically derived capillary pressure model. Comparing with other control‒oriented models in the literature, the developed model improves accuracy and provides more insights of the liquid water transport during transient response.

Fresh water resources are critical for daily human consumption. Therefore, a continuous monitoring effort over their quantity and quality is instrumental. One important model for water quantity monitoring is the rainfall-runoff model, which represents the response of a watershed to the variability of precipitation, thus estimating the discharge of a channel (Bedient and Huber, 2002, Beven, 2012). Remote sensing and satellite geodetic observations are capable to provide critical hydrological parameters, which can be used to support hydrologic modeling. For the case of satellite radar altimetry, limited temporal resolutions (e.g., satellite revisit period) prohibit the use of this method for a short (less than weekly) interval monitoring of water level or discharge. On the other hand, the current satellite radar altimeter footprints limit the water level measurement for rivers wider than 1 km (Birkett, 1998, Birkett et al., 2002). Some studies indeed reported successful retrieval of water level for small-size rivers as narrow as 80 m (Kuo and Kao, 2011, Michailovsky et al., 2012); however, the processing of current satellite altimetry signals for small water bodies to retrieve accurate water levels, remains challenging. To address this scientific challenge, this study poses two main objectives: (1) to monitor small (40-200 m width) and medium-sized (200-800 m width) rivers and lakes using satellite altimetry through identification and choice of the over-water radar waveforms corresponding to the appropriately waveform-retracked water level; and (2) to develop a rainfall-runoff hydrological model to represent the response of mesoscale watershed to the variability of precipitation. Both studies address the humid tropics of Southeast Asia, specifically in Indonesia, where similar studies do not yet exist. This study uses the Level 2 radar altimeter measurements generated by European Space Agency’s (ESA’s) Envisat (Environmental Satellite) mission. The first study proves that satellite altimetry provides a good alternative or the only means in some regions to measure the water level of medium-sized river (200-800 m width) and small lake (extent less than 1000 km2) in Southeast Asia humid tropic with reasonable accuracy. In addition, the procedure to choose retracked Envisat altimetry water level heights via identification or selection of over water waveform shapes is reliable; therefore this study concluded that the use of waveform shape selection procedure should be a standard measure in determining qualified range measurements especially over small rivers and lakes. This study also found that Ice-1 is not necessarily the best retracker as reported by previous studies, among the four standard waveform retracking algorithms for Envisat altimetry observing hydrologic bodies. The second study modeled the response of the poorly-gauged watershed in the Southeast Asia’s humid tropic through the application of Hydrologic Engineering Center ---Hydrologic Modeling System (HEC-HMS). The performance evaluation of HEC-HMS discharge estimation confirms a good match between the simulated discharges with the observed ones. As the result of precipitation data analysis, this study found that Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) is the preferred input forcing for the model, given the thorough evaluation of its relationship with field-measured precipitation data prior to its use as primary climatic forcing. This research also proposes a novel approach to process the TRMM precipitation estimation spatially through Thiessen polygon and area average hybrid method, which model the spatial distribution of TRMM data to match the spatial location of field meteorological stations. Through a simultaneous validation that compares the water level anomaly transformed from HEC-HMS simulated discharge and satellite altimetry measurement, this study found that satellite altimetry measures water level anomaly closer to the true water level anomaly than the water level anomaly converted from HEC-HMS simulated discharge. Some critical recommendations for future studies include the use of waveform shape selection procedure in the satellite altimetry based water level measurement of small and medium-sized rivers and small lakes, as well as the exploration to implement data assimilation between satellite altimetry and the hydrologic model for better discharge and water level estimations.

To reach the goal of grid parity, the cost of crystalline solar cells need to be reduced considerably. This can be done by using cheaper materials, such as thinner or lower quality wafers, or by reducing manufacturing costs, both process and material costs. Increasing the efficiencies of the devices while maintaining low costs via simple fabrication schemes is an ideal combination. The benefits of selective emitter have been known and quantified for many years. However, the adaptation of selective emitter solar cell designs into mass-production has been quite slow due to the relatively complex processing steps involved in applying such a design. This thesis begins with a review of various existing selective emitter solar cell technologies. A method of creating a selective emitter is then selected to be the main focus of the thesis due to its simple yet powerful features. This method is laser-doping through a dielectric layer. A new solar cell structure that employs the laser-doping process combined with a self-aligned metallisation method is then introduced, termed Laser-Doped Selective Emitter (LDSE) solar cell. A study is then presented to help further understanding of the laser-doping through dielectric process. Investigative work combines the use of defect Yang etch, SEM and EBIC analysis, light JV curve measurements and local ideality factor derived from dark JV curve measurements. These investigations help to identify several challenges associated with the laser-doping process. Theories on the causes of these challenges are then presented along with possible solutions. One of the most critical findings is the use of a stacked layer consisting of a thin layer of thermally grown SiO2 and PECVD SiNx to prevent laser-induced defects. Next, several characterisation methods that include four point-probes, Secondary Ion Mass Spectrometry (SIMS), spreading sheet resistance, Electron Beam Induced Current (EBIC) analysis and photoluminescence imaging are utilised to measure the sheet resistances, doping profiles and lifetime of the laser-doped region. These measurement techniques are used to optimise the laser parameters and other processing parameters involved in the fabrication of LDSE solar cells. In the final chapter, a novel self-aligned metallisation method that utilises the solar cell’s ability to produce voltage and current is investigated. It is found that this photoplating method is well-suited for fabrication of LDSE cells and potentially suitable in mass-production. Finally, the integration of the optimised process flow and parameters combined with the photoplating method is demonstrated through the fabrication and characterisation of a batch of LDSE solar cells made of commercial 125mm 1 Ω.cm p-type wafers. Efficiencies of up to 19% with VOC in excess of 635 mV and JSC close to 38 mA/cm2 are reported on 125 mm commercial grade CZ p-type wafers. The use of typical production line equipments for most of the fabrication steps is also demonstrated.

The increasing capabilities of multimedia appliances demand arithmetic circuits with higher speed and reasonable power dissipation. A common technique to attain those goals is synchronous pipelining, which increases the throughput of a circuit at the expense of longer latency, and it is therefore suitable where throughput takes priority over latency. Two synchronous pipelining approaches, conventional pipelining and wave pipelining, are commonly employed. Conventional pipelining uses registers to divide the circuit into shorter paths and synchronize among sub-blocks, while wave pipelining uses the delay of combinational elements to perform those tasks. As wave pipelining does not introduce additional registers, in principle, it can attain a higher throughput and lower power consumption. However, its throughput is limited by delay variations, while delay balancing often leads to increased power dissipation. This dissertation proposes a hybrid pipelining method called HyPipe, which divides the circuit into sub-blocks using conventional pipelining, and applies wave pipelining to each sub-block. Each sub-block is derived from a single base circuit, leading to a better delay balance and greater throughput than with heterogeneous circuits. Another requirement for wave pipelining to achieve high speed is short signal rise and fall times. Since CMOS wide-NAND and wide-NOR gates exhibit long rise and fall times and large delay variations, they should be decomposed. We show that the straightforward decomposition using alternating levels of NAND and NOR gates results in large delay variations. Therefore, we propose a new decomposition method using only one gate type. Our method reduces delay variations by up to 39%, and it is appropriate for wave pipelining based on standard-cells or sea-of-gates. We laid out a 4x4 HyPipe multiplier as a proof of concept and performed a post-layout SPICE simulation. The multiplier achieves a throughput of 4.17 billion multiplications per second or a clock period of 2.52 four-load inverter delays, which is almost twice the speed of any existing multiplier in the open literature. When the supply voltage is reduced to 1.2 V from 1.8 V, its power consumption is reduced from 76.2 mW to 18.2 mW while performing 2.33 billion multiplications per second.

Motivated by the presence of uncertainty in real data, in this research we investigate a robust optimization approach applied to multiclass support vector machines (SVMs) and support vector regression. Two new kernel based-methods are developed to address data with uncertainty where each data point is inside a sphere of uncertainty. For classification problems, the models are called robust SVM (R-SVM) and robust feasibility approach (R-FA) respectively as extensions of SVM approach. The two models are compared in terms of robustness and generalization error. For comparison purposes, the robust minimax probability machine (MPM) is applied and compared with the above methods. From the empirical results, we conclude that the R-SVM performs better than robust MPM. For regression problems, the models are called robust support vector regression (R-SVR) and robust feasibility approach for regression (R-FAR.). The proposed robust methods can improve the mean square error (MSE) in regression problems.

Islam in Indonesia is acknowledged as moderate, although there are radical Islamic groups that are involved in violent religious conflicts and insist on the implementation of Islamic law in the post-authoritarian Soeharto era. The moderation of Islam in Indonesia is not merely because of historical factors, but is also the result of ongoing debates on how to reconcile Islam with modernity. Jaringan Islam Liberal/JIL (the Liberal Islam Network), a network of young Muslim intellectuals, emerges as a forum to disseminate liberal interpretations of Islam. This study is to determine whether JIL’s liberal Islam is meant to develop an Islamic conception of liberalism or an Islamic liberal theology. This study shows that JIL’s liberal Islam is the continuation of Islamic renewal projects by Islamic neomodernists. The ideas proposed by JIL activists mostly deal with the compatibility of Islam and democracy, especially on the issues of toleration, pluralism, secularization, and individual and women’s rights. This network is very significant to the development of liberal Islamic ideas and the future of moderation of Islam in predominantly Muslim countries like Indonesia.

The West End in Cincinnati is a neighborhood with rich history. Trough decades, it has undergone transformation from a colorful, diverse neighborhood into a troubled, under-populated one. Displacements have disrupted the previous clearly-defined urban structure. The following project puts forth proposal for a redevelopment of the Northeast quadrant of the West End, part of the neighborhood that relatively remain intact over time. Its history of displacement serves as the basic theme. The proposal addresses the issue in the neighborhood from morphological standpoint. In putting together the plan, it employs several urban design approaches, which are the figure/ground analysis, imageability, serial vision, and defensible space. However, the proposal also acknowledges that the West End needs a broader approach, involving social, economic, political effort beside physical one.

In this work, a simplified method for performing characterization of a standard cell is presented. The method presented here is based on Synopsys models of cell delay and power dissipation, in particular the linear delay model. This model is chosen as it allows rapid characterization with a modest number of simulations, while still achieving acceptable accuracy. Additionally, a guideline for developing standard cell libraries for use with Synopsys synthesis and simulation tools and Cadence Placement-and-Routing tools is presented. A cell layout library, built in accordance with the presented guidelines, was laid out, and a test chip, namely a dual 4-bit counter, was built using the library to demonstrate the suitability of the method.

As cold-formed steel decks are used in virtually every steel-framed structure for composite slab systems, efforts to develop more efficient composite floor systems continues. Efficient composite floor systems can be obtained by optimally utilizing the materials, which includes the possibility of developing long span composite slab systems. For this purpose, new deck profiles that can have a longer span and better interaction with the concrete slab are investigated. Two new mechanical based methods for predicting composite slab strength and behavior are introduced. They are referred to as the iterative and direct methods. These methods, which accurately account for the contribution of parameters affecting the composite action, are used to predict the strength and behavior of composite slabs. Application of the methods in the analytical and experimental study of strength and behavior of composite slabs in general reveals that more accurate predictions are obtained by these methods compared to those of a modified version of the Steel Deck Institute method (SDI-M). A nonlinear finite element model is also developed to provide additional reference. These methods, which are supported by elemental tests of shear bond and end anchorages, offer an alternative solution to performing a large number of full-scale tests as required for the traditional m-k method. Results from 27 composite slab tests are compared with the analytical methods. Four long span composite slab specimens of 20 ft span length, using two different types of deck profiles, were built and tested experimentally. Without significantly increasing the slab depth and weight compared to those of composite slabs with typical span, it was found that these long span slabs showed good performance under the load tests. Some problems with the vibration behavior were encountered, which are thought to be due to the relatively thin layer of concrete cover above the deck rib. Further study on the use of deeper concrete cover to improve the vibrational behavior is suggested. Finally, resistance factors based on the AISI-LRFD approach were established. The resistance factors for flexural design of composite slab systems were found to be f=0.90 for the SDI-M method and f=0.85 for the direct method.

Highway bridge no. GRE-35-1199 was built in Greene county, Xenia, Ohio. The project was started on October 1990. During the bridge construction, performance of the spread footing foundation that was placed on the silty sand layer was recorded. Two kinds of instruments were installed to monitor the footing settlements and wall tilts. A laboratory experiment was also conducted to determine settlements of the footings. Two alluminum models of footing at 1/50 and 1/60 of scale were tested in a centrifuge instrument. Beside that, the settlement of the footing was computed by using several methods. Comparing the three methods of investigations, it appears that a centrifuge experiment is reliable to determine footing settlement. To predict the settlement of footing on silty sand layer, the general equation of settlement on an elastic foundation that was modified by Bowles is available. Several empirical equations, such as proposed by Terzaghi and Peck, Peck and Bazaraa, and D'Appolonia give more economical dimensions of the footings.

Composite diaphragm strength and behavior were studied using non-linear finite element analysis. A total of 57 three panel diaphragm models were analyzed to failure. Parameters studied included beam size and orientation, panel dimension, connector type and distance, slab opening, yield plateau, and beam connection flexibility. Shear connector, deck-to-concrete interface, and beam connection were the components modeled non-linearly. Orthotropic behavior was used for the deck elements. 2-D and 3-D contours of concrete slab, steel deck and deck-to-concrete interfacial stresses and connector forces are presented to clearly show the behavior of the diaphragm in relation with the component behavior. Complete and incomplete connector force redistributions were observed and an expression of yield plateau length required to develop a complete connector force redistribution was developed. Expressions for diaphragm strength based on beam, beam connection and connector strength for both the complete and incomplete connector force redistribution cases were presented. The diaphragm strength predicted by the expression compared favorably with the finite element results.

This study examines the application of high-strength concrete (HSC) in structural walls of tall buildings. Emphasis is put on the cost-benefits corresponding to the use of higher concrete strengths. The parameters included in the cost analysis are: the material cost of concrete and reinforcing steel; the construction costs including the placement costs of the steel reinforcement and wet concrete, and the formwork cost; and the cost-benefit additional floor area gains, corresponding to thinner walls resulted from applications. In lateral load resisting buildings, HSC are more likely to be used in the structural columns and walls. It is shown in the review of literature (Chapter 2) that the utilisations of HSC in building applications are economical. The work done so far was mostly involving the use of HSC columns in the medium-rise buildings. The cost analyses carried out in this thesis reveals that significant cost-benefits can also be achieved in the HSC walls. Comparing to the 40 MPa concrete, a 120 MPa concrete wall building capitalising at $8,000 per square meter results in a cost-benefit more than 2.5 times the construction costs of the 40 MPa wall, a significant amount. The structural walls investigated are two-dimensional cantilever and coupled walls, and a threerdimensional core wall comprising two 'C' shape walls and header beams coupling the two walls. The results of the investigations are presented in Chapters 6 and 7. A case study of a model 30-storey building is also given in Chapter 8. This study concluded that the use of HSC in structural wall buildings is recommended.