11,334 research outputs found

    INVESTIGATING THE PERCEPTION OF EXPATRIATES TOWARDS IMMIGRATION SERVICE QUALITY IN SHARJAH, UNITED ARAB EMIRATES THROUGH MIXED METHOD APPROACH

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    The public sectors in UAE are under immense pressure to demonstrate that their services are customer-focused and that continuous performance improvement is being delivered. The United Arab Emirates is a favoured destination for expatriates due to its own citizens form a minority of the population and are barely represented in the private sector workforce. These highly unusual demographics confer high importance on the national immigration services. Recently, increased interest in international migration, specifically within the United Arab Emirates, has been shown both by government agencies and by the governments of industrialised countries. Given the importance of the expatriate labour force to economic stability and growth in the Emirates, this research investigates how immigration services are perceived, with the aim of contributing to their improvement, thus ultimately supporting economic growth. It proposes a service quality perception framework to improve understanding within SID of how to raise levels of service delivered to migrants and other persons directly or indirectly affected by SID services. Qualitative data were collected by means of semi-structured interviews and quantitative data by means of a questionnaire survey based on the abovementioned framework. The survey data, on the variables influencing participants’ experiences and perceptions of SID services, were subjected to statistical analysis. The framework was then used to evaluate quality of service in terms of general impressions, delivery, location, response, SID culture and behaviour. Numerical data were analysed using inferential and descriptive statistics. It was found that service quality positively influenced service behaviour and that this relationship was mediated by SID culture. This research makes an original contribution to knowledge as one of the few studies of immigration to the United Arab Emirates. By examining the workings of one immigration department, it adds to the literature on immigration departments and organisational development in developing countries. It illuminates the mechanics of immigration services and demonstrates their increasing importance to the world economy

    Annals [...].

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    Pedometrics: innovation in tropics; Legacy data: how turn it useful?; Advances in soil sensing; Pedometric guidelines to systematic soil surveys.Evento online. Coordenado por: Waldir de Carvalho Junior, Helena Saraiva Koenow Pinheiro, Ricardo Simão Diniz Dalmolin

    A suite of quantum algorithms for the shortestvector problem

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    Crytography has come to be an essential part of the cybersecurity infrastructure that provides a safe environment for communications in an increasingly connected world. The advent of quantum computing poses a threat to the foundations of the current widely-used cryptographic model, due to the breaking of most of the cryptographic algorithms used to provide confidentiality, authenticity, and more. Consequently a new set of cryptographic protocols have been designed to be secure against quantum computers, and are collectively known as post-quantum cryptography (PQC). A forerunner among PQC is lattice-based cryptography, whose security relies upon the hardness of a number of closely related mathematical problems, one of which is known as the shortest vector problem (SVP). In this thesis I describe a suite of quantum algorithms that utilize the energy minimization principle to attack the shortest vector problem. The algorithms outlined span the gate-model and continuous time quantum computing, and explore methods of parameter optimization via variational methods, which are thought to be effective on near-term quantum computers. The performance of the algorithms are analyzed numerically, analytically, and on quantum hardware where possible. I explain how the results obtained in the pursuit of solving SVP apply more broadly to quantum algorithms seeking to solve general real-world problems; minimize the effect of noise on imperfect hardware; and improve efficiency of parameter optimization.Open Acces

    Digital asset management via distributed ledgers

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    Distributed ledgers rose to prominence with the advent of Bitcoin, the first provably secure protocol to solve consensus in an open-participation setting. Following, active research and engineering efforts have proposed a multitude of applications and alternative designs, the most prominent being Proof-of-Stake (PoS). This thesis expands the scope of secure and efficient asset management over a distributed ledger around three axes: i) cryptography; ii) distributed systems; iii) game theory and economics. First, we analyze the security of various wallets. We start with a formal model of hardware wallets, followed by an analytical framework of PoS wallets, each outlining the unique properties of Proof-of-Work (PoW) and PoS respectively. The latter also provides a rigorous design to form collaborative participating entities, called stake pools. We then propose Conclave, a stake pool design which enables a group of parties to participate in a PoS system in a collaborative manner, without a central operator. Second, we focus on efficiency. Decentralized systems are aimed at thousands of users across the globe, so a rigorous design for minimizing memory and storage consumption is a prerequisite for scalability. To that end, we frame ledger maintenance as an optimization problem and design a multi-tier framework for designing wallets which ensure that updates increase the ledger’s global state only to a minimal extent, while preserving the security guarantees outlined in the security analysis. Third, we explore incentive-compatibility and analyze blockchain systems from a micro and a macroeconomic perspective. We enrich our cryptographic and systems' results by analyzing the incentives of collective pools and designing a state efficient Bitcoin fee function. We then analyze the Nash dynamics of distributed ledgers, introducing a formal model that evaluates whether rational, utility-maximizing participants are disincentivized from exhibiting undesirable infractions, and highlighting the differences between PoW and PoS-based ledgers, both in a standalone setting and under external parameters, like market price fluctuations. We conclude by introducing a macroeconomic principle, cryptocurrency egalitarianism, and then describing two mechanisms for enabling taxation in blockchain-based currency systems

    The Impact of a Play Intervention on the Social-Emotional Development of Preschool Children in Riyadh, Saudi Arabia

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    Practitioners working with children have emphasized that play is vital to children’s development, Links between children’s social-emotional development and play have been widely documented. However, rigorous research evidence of these links remains limited. This study’s objectives were to measure the impact of play on children’s social-emotional development in the kingdom of Saudi Arabia; identify teachers’ viewpoints around the use of play intervention; and understand the children’s experience of play intervention. Fifty-nine children aged between five and six years, with mean age of 5.5 (SD 3.376) and eight teachers participated in the study. The study used a mixed-method strategy including questionnaires, interviews, and focus group discussions. Children’s social-emotional development was measured by using the Strengths and Difficulties Questioner (SDQ). A pre-/post-test counterbalanced design was used to measure the impact of the play intervention on children’s development. Teachers’ perspectives on play were obtained by interviewing eight teachers. Children’s views were gathered through focus group discussions. Repeated measures ANOVA was conducted to determine the differences in the SDQ score over three time points. Results showed that using unstructured loose parts play had positively impacted children’s social-emotional development. After participation in the play intervention, scores from the SDQ indicated that children demonstrated significantly less problematic emotional, conduct and peer relationship issues. They also scored significantly higher in their positive prosocial behaviour. These positive effects were sustained after six weeks of stopping the intervention. The play intervention did not however impact children’s hyperactivity level. The interviews analysis illustrates four main themes: concept and characteristics of play, play functions, developmental benefits of play, and play and practice. Regarding children’s discussion, affordance emerged as a main theme; this includes emotional, social, and functional affordances. Unstructured loose parts play intervention was demonstrated to have positive impacts on children’s social-emotional development. The study’s findings support the view that play is a way to increase children’s development

    Examining the Impact of Personal Social Media Use at Work on Workplace Outcomes

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    A noticable shift is underway in today’s multi-generational workforce. As younger employees propel digital workforce transformation and embrace technology adoption in the workplace, organisations need to show they are forward-thinking in their digital transformation strategies, and the emergent integration of social media in organisations is reshaping internal communication strategies, in a bid to improve corporate reputations and foster employee engagement. However, the impact of personal social media use on psychological and behavioural workplace outcomes is still debatebale with contrasting results in the literature identifying both positive and negative effects on workplace outcomes among organisational employees. This study seeks to examine this debate through the lens of social capital theory and study personal social media use at work using distinct variables of social use, cognitive use, and hedonic use. A quantitative analysis of data from 419 organisational employees in Jordan using SEM-PLS reveals that personal social media use at work is a double-edged sword as its impact differs by usage types. First, the social use of personal social media at work reduces job burnout, turnover intention, presenteeism, and absenteeism; it also increases job involvement and organisational citizen behaviour. Second, the cognitive use of personal social media at work increases job involvement, organisational citizen behaviour, employee adaptability, and decreases presenteeism and absenteeism; it also increases job burnout and turnover intention. Finally, the hedonic use of personal social media at work carries only negative effects by increasing job burnout and turnover intention. This study contributes to managerial understanding by showing the impact of different types of personal social media usage and recommends that organisations not limit employee access to personal social media within work time, but rather focus on raising awareness of the negative effects of excessive usage on employee well-being and encourage low to moderate use of personal social media at work and other personal and work-related online interaction associated with positive workplace outcomes. It also clarifies the need for further research in regions such as the Middle East with distinct cultural and socio-economic contexts

    Development of MEMS - based IMU for position estimation: comparison of sensor fusion solutions

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    With the surge of inexpensive, widely accessible, and precise Micro-Electro Mechanical Systems (MEMS) in recent years, inertial systems tracking move ment have become ubiquitous nowadays. Contrary to Global Positioning Sys tem (GPS)-based positioning, Inertial Navigation System (INS) are intrinsically unaffected by signal jamming, blockage susceptibilities, and spoofing. Measure ments from inertial sensors are also acquired at elevated sampling rates and may be numerically integrated to estimate position and orientation knowledge. These measurements are precise on a small-time scale but gradually accumulate errors over extended periods. Combining multiple inertial sensors in a method known as sensor fusion makes it possible to produce a more consistent and dependable un derstanding of the system, decreasing accumulative errors. Several sensor fusion algorithms occur in literature aimed at estimating the Attitude and Heading Reference System (AHRS) of a rigid body with respect to a reference frame. This work describes the development and implementation of a low-cost, multi purpose INS for position and orientation estimation. Additionally, it presents an experimental comparison of a series of sensor fusion solutions and benchmarking their performance on estimating the position of a moving object. Results show a correlation between what sensors are trusted by the algorithm and how well it performed at estimating position. Mahony, SAAM and Tilt algorithms had best general position estimate performance.Com o recente surgimento de sistemas micro-eletromecânico amplamente acessíveis e precisos nos últimos anos, o rastreio de movimento através de sistemas de in erciais tornou-se omnipresente nos dias de hoje. Contrariamente à localização baseada no Sistema de Posicionamento Global (GPS), os Sistemas de Naveg ação Inercial (SNI) não são afetados intrinsecamente pela interferência de sinal, suscetibilidades de bloqueio e falsificação. As medições dos sensores inerciais também são adquiridas a elevadas taxas de amostragem e podem ser integradas numericamente para estimar os conhecimentos de posição e orientação. Estas medições são precisas numa escala de pequena dimensão, mas acumulam grad ualmente erros durante longos períodos. Combinar múltiplos sensores inerci ais num método conhecido como fusão de sensores permite produzir uma mais consistente e confiável compreensão do sistema, diminuindo erros acumulativos. Vários algoritmos de fusão de sensores ocorrem na literatura com o objetivo de estimar os Sistemas de Referência de Atitude e Rumo (SRAR) de um corpo rígido no que diz respeito a uma estrutura de referência. Este trabalho descreve o desenvolvimento e implementação de um sistema multiusos de baixo custo para estimativa de posição e orientação. Além disso, apresenta uma comparação experimental de uma série de soluções de fusão de sensores e compara o seu de sempenho na estimativa da posição de um objeto em movimento. Os resultados mostram uma correlação entre os sensores que são confiados pelo algoritmo e o quão bem ele desempenhou na posição estimada. Os algoritmos Mahony, SAAM e Tilt tiveram o melhor desempenho da estimativa da posição geral

    Graphical scaffolding for the learning of data wrangling APIs

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    In order for students across the sciences to avail themselves of modern data streams, they must first know how to wrangle data: how to reshape ill-organised, tabular data into another format, and how to do this programmatically, in languages such as Python and R. Despite the cross-departmental demand and the ubiquity of data wrangling in analytical workflows, the research on how to optimise the instruction of it has been minimal. Although data wrangling as a programming domain presents distinctive challenges - characterised by on-the-fly syntax lookup and code example integration - it also presents opportunities. One such opportunity is how tabular data structures are easily visualised. To leverage the inherent visualisability of data wrangling, this dissertation evaluates three types of graphics that could be employed as scaffolding for novices: subgoal graphics, thumbnail graphics, and parameter graphics. Using a specially built e-learning platform, this dissertation documents a multi-institutional, randomised, and controlled experiment that investigates the pedagogical effects of these. Our results indicate that the graphics are well-received, that subgoal graphics boost the completion rate, and that thumbnail graphics improve navigability within a command menu. We also obtained several non-significant results, and indications that parameter graphics are counter-productive. We will discuss these findings in the context of general scaffolding dilemmas, and how they fit into a wider research programme on data wrangling instruction

    'Inventions and adventures': the work of the Stevenson engineering firm in Scotland, c. 1830 - c. 1890

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    This thesis examines the work of the nineteenth-century Stevenson civil engineering firm to argue that civil engineering should be approached geographically both because it takes place in and is shaped by particular spaces, but also because the result of such work reshapes space and the relationship between places. Geographers have extensively analysed the ways in which humans have worked to alter environments, but relatively little attention has been paid to engineering as a socially and geographically transformative process, to the technical questions and to the engineering professionals whose work brought about such change. This thesis analyses engineers as social and technical agents of environmental change, rather than viewing their role as the simple implementation of directives developed elsewhere and by others. It combines insights from the history and historical geography of science, environmental history and the history of technology to make a case for the relevance of an historical geography of engineering. The thesis explores these issues through the work of the Stevenson family. The Stevensons were an Edinburgh-based and internationally-renowned firm of engineers who specialised in the construction of coastal infrastructure. The start and end dates of the thesis indicate, broadly, the careers of David and Thomas Stevenson, who jointly managed the family firm under the name D. & T. Stevenson between 1850 and 1886. The empirical basis for this thesis draws upon the detailed analysis of the firm’s archival records: technical publications, project reports, diaries, correspondence, maps, plans and diagrams. The work of the Stevensons—their engineering epistemologies, practices, and professional identities— are examined through four diverse projects undertaken by the firm in the nineteenth century. These projects are: the training of new engineers; surveying and designing improvement works for the rivers Tay and Clyde; the implementation of a coastal sound-based fog signal network; and the failed attempt to expand Wick harbour through the construction of a breakwater. These projects highlight the range of activities undertaken by nineteenth-century engineers and illustrate the ‘making’ of engineers and the work they did by highlighting training and learning, surveying, maintenance, testing, evaluation, repair and the explanation of failure. With reference to these projects and by drawing upon relevant contextual material, the thesis examines the conceptualisation of geographical space and natural forces in engineering, the relationship between science and engineering, the nature of expertise and notions of engineering judgement, and the role of family, legacy and reputation in securing professional credibility and status. This approach challenges older historiographical traditions which portrayed engineers as individual geniuses. The thesis instead understands engineering to be a combination of specialist knowledge and tacit skill and situates engineers within their social and institutional networks of power and authority. In pointing out that some engineering works failed, the thesis challenges the tendency in histories of engineering works to focus on success. It makes the case for an historical geography of engineering as a way of understanding engineering as an activity, a status and as processes which changed human-environment relations

    Applications and practical considerations of polarisation structuring by a Fresnel cone

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    The polarisation property of light has been known about for hundreds of years. Often its use in technology has been limited to uniform states, however, more recently light with structured polarisation has gained interest. This is largely prompted by availability of spatial light modulators for generation, and increased computation speed to model complex focal fields. My PhD research has extended upon work carried out during a master’s project where we investigated the use of a solid glass cone (so-called Fresnel cone) for generating vector vortex beams. The aim of this thesis is to report on the potential use of a Fresnel cone in microscopy and polarimetry applications, and practical implications discovered. Expanding on the previous work, enhanced fidelity polarisation states are measured and a newly developed Fresnel cone coupling technique is shown, allowing high-efficiency annular vector vortex beam generation. We demonstrate through simulations based on vector diffraction theory that azimuthally polarised light with OAM generated using a Fresnel cone can provide sub-diffraction limited focal spots, below those of more well-known radially polarised light. Practical implications were encountered, prompting investigation into the effects of phase aberrations on resulting focal spots, and experimental measurement of cone surface topology. We find the uniformity of the Fresnel cone shape and apex angle is crucial to the focussing properties. For polarimetry application, full details are provided for a single-shot full-Stokes polarimeter technique and proof-of-principle experiment, where broadband operation is demonstrated. I conclude by summarising the findings of my research and suggest potential future work in this area
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