55 research outputs found

    SIMBA: scalable inversion in optical tomography using deep denoising priors

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    Two features desired in a three-dimensional (3D) optical tomographic image reconstruction algorithm are the ability to reduce imaging artifacts and to do fast processing of large data volumes. Traditional iterative inversion algorithms are impractical in this context due to their heavy computational and memory requirements. We propose and experimentally validate a novel scalable iterative mini-batch algorithm (SIMBA) for fast and high-quality optical tomographic imaging. SIMBA enables highquality imaging by combining two complementary information sources: the physics of the imaging system characterized by its forward model and the imaging prior characterized by a denoising deep neural net. SIMBA easily scales to very large 3D tomographic datasets by processing only a small subset of measurements at each iteration. We establish the theoretical fixedpoint convergence of SIMBA under nonexpansive denoisers for convex data-fidelity terms. We validate SIMBA on both simulated and experimentally collected intensity diffraction tomography (IDT) datasets. Our results show that SIMBA can significantly reduce the computational burden of 3D image formation without sacrificing the imaging quality.https://arxiv.org/abs/1911.13241First author draf

    Greener carbon capture using microwave heating for the development of cellulose-based adsorbents

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    Acknowledgements For the purpose of open access, the author has applied a Creative Commons Attribution (CC679 BY) licence to any Author Accepted Manuscript version arising from this submission. Simbarashe Biti, a Leverhulme Trust Doctoral Scholar, is part of the 15 PhD scholarships of the ‘Leverhulme Centre for Doctoral Training in Sustainable Production of Chemicals and Materials’ at the University of Aberdeen (Scotland, United Kingdom). Elemental analysis data was produced with the assistance of the analytical facilities in the School of Chemistry at the University of Birmingham. Claudia Fernández Martín thanks the Development Trust, Grant 1155, awarded for the adquisition of the microwave apparatus FlexiWave from Milestone used for this study.m.Peer reviewe

    Perancangan Website Sebagai Media Promosi Dan Penjualan Pada CV Simba Jaya Magelang

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    ABSTRACT - Simba CV Jaya is one of the few providers of goods of daily needs of society in general. Conventional sales methods still make the information less widely accessible. Making a website titled Designing Website As Media Promotion and Sales at Simba Jaya CV Magelang is expected to improve the promotion, sales and enable customers to order products. In making the website the author uses the method of data collection among others by observation, interviews, and literature. While the software development method uses four stages, with the waterfall method of software that includes analysis, design, code generation and testing program. The purpose of making a website is to enable customers to access information or transactions and increase the consumer appeal of the product is marketed. Keywords: websites, e-commerce, promotion, sales, CV Simba Jaya ABSTRAKSI - CV Simba Jaya merupakan salah satu dari beberapa perusahaan penyedia barang kebutuhan sehari-hari masyarakat pada umumnya. Metode penjualan yang masih konvensional menjadikan informasi kurang luas untuk diakses. Pembuatan website dengan judul Perancangan Website Sebagai Media Promosi dan Penjualan pada CV Simba Jaya Magelang diharapkan bisa meningkatkan promosi, penjualan serta memudahkan konsumen dalam melakukan pemesanan produk. Dalam pembuatan website penulis menggunakan metode pengumpulan data antara lain dengan cara observasi, wawancara dan studi pustaka. Sedangkan metode pengembangan perangkat lunak menggunakan empat tahap yaitu dengan metode waterfall yang meliputi analisa perangkat lunak, desain, pembuatan kode program dan pengujian. Tujuan pembuatan website ialah untuk memudahkan konsumen dalam mengakses informasi atau transaksi serta meningkatkan daya tarik konsumen terhadap produk yang di pasarkan. Kata Kunci: website, e-commerce, promosi, penjualan, CV Simba Jay

    Numerical estimation of EMI impact on implantable cardiac pacemakers in elevator using EMF distributions inside human body

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    © 2010 IEEE. Reprinted, with permission, from Hikage, T., Nojima, T., Simba, A.Y., Watanabe, S., Numerical estimation of EMI impact on implantable cardiac pacemakers in elevator using EMF distributions inside human body, 2010 IEEE Antennas and Propagation Society International Symposium (APSURSI), Jul. 2010. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Hokkaido University products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it

    Sustainable microcrystalline cellulose-based activated carbons for a greener carbon capture at post-combustion conditions

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    Open Access via the Elsevier Agreement Authors would like to thank The Leverhulme Trust for the funding provided through the Grant DS-2017-073. Simbarashe Biti, a Leverhulme Trust Doctoral Scholar, is part of the 15 PhD scholarships of the ‘Leverhulme Centre for Doctoral Training in Sustainable Production of Chemicals and Materials’ at the University of Aberdeen (Scotland, United Kingdom). Surface morphology data was completed with the assistance of the ACEMAC SEM facility at the University of Aberdeen. Elemental analysis data was produced with the assistance of the Analytical Facilities in the School of Chemistry at the University of Birmingham.Peer reviewe

    Production, Activation and CO2 Uptake Capacity of a Carbonaceous Microporous Material from Palm Oil Residues

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    While Malaysia produces about half of the world’s palm oil and is the largest producer and exporter worldwide, oil palm industries generate large amounts of lignocellulosic biomass waste as a sub-product with no economic market value other than feedstock for energy valorisation. With the aim to increase the sustainability of the sector, in this work we prepare new materials for CO2 capture from palm oil residues (empty fruit bunches and kernels). The biochar is obtained through the carbonisation of the residues and is physically and chemically activated to produce porous materials. The resulting microporous samples have similar properties to other commercial activated carbons, with BET surfaces in the 320–880 m2/g range and pore volumes of 0.1–0.3 cm3·g−1. The CO2 uptake at room temperature for physically activated biochar (AC) was 2.4–3.6 mmolCO2/gAC, whereas the average CO2 uptake for chemically activated biochar was 3.36–3.80 mmolCO2/gAC. The amount of CO2 adsorbed decreased at the highest temperature, as expected due to the exothermic nature of adsorption. These findings confirm the high potential of palm oil tree residues as sustainable materials for CO2 capture

    Measuring and Creating Cognitive-Behavioural Associations: Testing a Social Identity Model of Behavioural Associations (SIMBA)

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    In 2014, author and speaker Tom Asacker presented the popular TED talk entitled “Why TED Talks don't change people's behaviors”—arguing that lasting behavioural change is only truly achievable by appealing to an individual’s identity and self-concept. His message, that “who we think we are, is why we do what we do” is fundamental to Social Identity Theory (Tajfel, 1978; Tajfel & Turner, 1979, 1986)—which posits that we derive an essential part of our self-concept from our group memberships. Rather than being external to the self, our group memberships and their content—including the consensual perceptions of what is normative for a given group—are internalised within the self-concept in the form of social identities (Tajfel, 1981; Turner, 1982, 1985). Properties of the social group, such as group norms, become subjectively interchangeable with personal norms and stereotypes—influencing thought and guiding action. Our social identities therefore provide some insight into who we are, what we think, and what we do (Abrams et al., 1990; Oakes et al., 1994; Reicher, 2001). Social identities are not only important in describing where we sit within our perceived social reality, but also in predicting what we will become; identities have the power to shape and change our future behaviour (Reicher, 2001). Implicit in both this messaging and social identity theorising is the suggestion that this relationship between social identity and behaviour may not be so straight forward; while it is true who we think we are contributes to how we behave, equally, the way we behave—and the extent to which it is seen to be normative for a given group—guides the groups we identify with. Therefore, our behaviour has implications for our self-concept. The acquisition of self-knowledge in this fashion is fundamental to theories of cognitive consistency—such as self-perception theory (Bem, 1972)—which posit that individuals infer their own attitudes, beliefs, and other internal states from observing their own behaviours and the circumstances under which they occur (Bem, 1972). For example, when a university student repeatedly engages in behaviours seen to be normative of the student identity—such as drinking (Davoren et al., 2016; John & Alwyn, 2014)—they may begin to reflect on this congruency between their own behaviour and the behaviour of other students. Over time, this individual may begin to identify more strongly as a student, as they perceive their behaviour to align with what it means to be a student. Failing to engage in such behaviours might (over time) even lead to disidentification from the group. This reciprocal causality is consistent with theories and research that examine the wider associative network of the self-concept (Greenwald & Pratkanis, 1984; Koffka, 1935), and has been modelled in relation to other social psychological constructs such a attitudes and self-esteem (e.g., the balanced identity design; Greenwald, Banaji, Rudman, et al., 2002, Dunham, 2013). While traditional and contemporary theories of social identity have focused primarily on different bivariate relationships among social identity, group norms and behaviour, these relationships are yet to be unified in a single, dynamic model that theorises how the interrelations among these self-relevant constructs emerge and are maintained. This thesis presents, and comprehensively tests, a Social Identity Model of Behavioural Associations (SIMBA)—a theoretical and methodological integration of both social (Tajfel, 1978; Tajfel & Turner, 1979; Turner et al., 1987) and balanced identity theorising (Greenwald, Banaji, Rudman, et al., 2002)—which models the relationships among social identification, group norms, and individual-level behaviour as reciprocal associative links in a triangular constellation. Throughout the thesis, the SIMBA is used explore two overarching research questions. First, we determine whether identity, norms, and behaviour can be measured—not only directly (i.e., via self-report), but also indirectly (i.e., via implicit measures) as cognitive associations among self-group, group-behaviour, and self-behaviour concepts. We also establish whether the three constructs demonstrate a mutually interactive relationship; that is, whether any one of the constructs may be explained by the interaction between the remaining two. Second, we aim to demonstrate reciprocal causality; beyond describing interactive relations among concepts, the SIMBA assumes that each construct is not only explained, but predicted by the remaining two. Therefore, we explore the cognitive processes through which identity, norms and behaviour are created, and determine whether cognitive balance emerges among them. Ultimately, the thesis tests the utility of the SIMBA as a theoretical framework for understanding the relation between, and the formation of, social identity, group norms, and individual-level behaviour. In Chapter 1, we review the relevant theories that underpin the theoretical and methodological assumptions of the SIMBA, that is, the theories relevant to the social identity approach (i.e., social identity theory and self-categorisation theory) and cognitive consistency (i.e., balance theory and balanced identity theory). These theories are discussed in terms of their origins and fundamental principles, while also highlighting the ways in which they have inspired and contributed to the development of contemporary theories in their respective fields. With regards to the social identity approach, we discuss how traditional social identity theorising has advanced through the development of models that consider social identity and group norms to be mutually interactive and influential in the formation of one another. Regarding theories of cognitive consistency, we discuss the way in which these theories have become increasingly broad in their applicability and explanatory potential—explaining cognitive balance in a variety of contexts such as interpersonal relations, social identity, and intergroup attitudes. In Chapter 2, we provide a theoretical overview of the SIMBA. The theory’s key predictions regarding measuring associations, creating associations, and changing associations are outlined, alongside the supporting literature that aided in their development. This chapter also discusses the ways in which the SIMBA theoretically and methodologically advances both SIT and BIT by drawing direct comparisons between the theories. This chapter ends with an overview of the thesis, which highlights the specific research questions that will be addressed in each empirical chapter, and the progression of ideas across chapters. Chapters 3 and 4 focus on testing the utility of the SIMBA for the measurement of self-group-behaviour associations. Across these chapters, we investigate the primary assumption of the SIMBA (i.e., the balance-congruity principle; that the strength of any one association in the SIMBA can be predicted by the interactive strength of the remaining two) in relation to a variety of group memberships and behaviours—establishing the generalisability of the SIMBA. In Chapter 3, we tested the SIMBA in the context of drinking behaviour in relation to student (Studies 1 and 2) and British national (Study 3) identities. These studies identified good support for the balance-congruity principle on implicit measures of social identity, group norms, and behaviour. Evidence for this prediction was weaker on explicit scale measures; we argue that this difference may be dependent on the explicit measures possessing theoretically meaningful zero-points. In Chapter 4, we tested the SIMBA in the context of social distancing behaviour in relation to the British national identity. Study 4 included two different types of explicit measure (e.g., traditional Likert-type scales and visual analogue scales); confirming that support on explicit measures was strong, and equal to that on implicit measures, when using visual analogue scales (i.e., measures that possess a zero-point indicative of associative indifference). We also assessed balance-congruity across two timepoints during the COVID-19 pandemic—finding cognitive balance to be stable over time. In Chapter 5, we step back from directly testing the assumptions of the SIMBA and adopt a network analytic approach to understanding the different social identities found to co-occur within individuals, and the behaviours thought to correspond with specific identities. This research was initially developed to help identify associated groups and behaviours to feature in future tests of the SIMBA—particularly for the measurement of associations, following on from Chapters 3 and 4—but the co-occurrences identified also serve as a meaningful resource for those conducting research into identities and their associated behaviours more generally. Therefore, while the chapter may appear to divert from the SIMBA narrative, it has an important function in progressing the theory (e.g., establishing its wider generalisability to multiple groups and behaviours), and social identity research more broadly. In Study 5, we generated three different network-types—identity-by-identity, behaviour-by-identity, and identity-by-behaviour—where we identified several identities and behaviours to significantly co-occur at a rate both higher and lower than chance. Although the overall structure of the networks was found to be significantly different than expected by chance, networks were low in modularity (i.e., there was no evidence of clustering within the data). In the final empirical chapter (i.e., Chapter 6) we focus on testing the utility of the SIMBA for the creation of novel self-group-behaviour associations. In two pilot studies, we established the initial efficacy of both the partial-IAT and probabilistic learning tasks for generating associations among concepts. After refining these methodologies, Study 6 directly compared them, and conducte

    Image pre-processing & data post-processing software dedicated to flow measurements in an automotive intake manifold

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    The SIMBA project had for objective to model the whole air loop of the automotive engine. In order to get boundary conditions for this model and verify it, PIV measurements were done. Simultaneously in the eight intake manifold\u92s runners of a DV6 TED4 PSA engine, acquisitions were obtained for each of the 720 crank angle degrees. Specific software (named PYV) was developed to pre-process images to deal with constraints inherent to running engine environment, and also to enable automate PIV processing

    Optimizing the PDDL domain of TUSP to improve planner performance: Modifying the domain to improve planner execution time, plan quality, and problem solvability

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    It is possible to improve the performance of planners by modifying the PDDL domain of a problem. The goal of this research is to implement this to the domain of the Train Unit Shunting Problem (TUSP). The research question we attempt to answer is: To what extent can we improve planner performance by optimizing the PDDL domain of TUSP? The main contributions of this research are: a formalization of the TUSP and its constraints in PDDL terminology, a comprehensive evaluation of the performance of planners on the PDDL domain of TUSP, provide general approaches and techniques that can be used to optimize a PDDL domain, and provide insights into the relationship between the performance of planners and PDDL domain properties. To answer the research question, we measure the performance of the planners in terms of execution time, plan quality, and problem solvability. We modified the domain by combining actions such that the number of computations is decreased and by introducing action costs. With these modifications, we found a decrease in planner execution time and an increase in plan quality. We found no difference in problem solvability. Therefore, we can conclude that we can indeed improve the performance of planners by implementing these modifications to the domain of TUSP.CSE3000 Research ProjectComputer Science and Engineerin
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