Dissertations / Theses on the topic 'CONEX framework'

Existing electronic markets are fragmented in the sense that each is an information island. The interoperation of product information between them is difficult especially in semantics communication. This prevents the formation of global electronic markets and the lowering distribution cost through market globalisation. The traditional and contemporary ap-proaches of product standardisation and ontology mediation could solve the problem only if all markets could adopt the same product standards, or mediation systems could mediate all heterogeneous standards and markets without semantic conflicts. However, problems generally exist in adopting a universal standard or mediating all markets through existing mediation systems. A reflection of the issue is that there are millions of ad hoc electronic product catalogues (EPCs) situated in small and medium sized enterprises (SMEs), where each EPC is a semantic community, often not aware of standards and mediation systems due to its ad hoc nature. This thesis focuses on the semantic integration of autonomous ad hoc EPCs, which are semantically inconsistent with each other. Firstly, a novel Collaborative Concept Exchange (CONEX) approach is developed for the se-mantic integration of ad hoc EPCs. Using this approach, a PRODUCT MAP is first built based on the theories of semiotic analysis and market segmentation. It functions as an analytical framework to articulate ad hoc EPCs, and answers the questions: what are the general char-acteristics of ad hoc EPCs, what are their heterogeneous relations, and how they are unevenly distributed in fragmented electronic markets. Within this framework, an abstract representa-tion of ad hoc EPCs is proposed using the articulated elements that are simple and manipu-lable. Major contributions of this framework include: the models of the abstract representa-tion of ad hoc EPCs on their structures, concepts and contexts; the semantic integration conditions of heterogeneous ad hoc EPCs; and a ConexNet of market network topology that captures the characteristics of ad hoc EPCs that are unevenly distributed in fragmented elec-tronic markets. Secondly, a three-layer CONEX information model is proposed to integrate ad hoc EPCs based on the PRODUCT MAP, which provides a trichotomy of systems, designers and users. The strategy behind the model is the separation of structure from concept and context, and hence they can be independently managed to resolve semantic conflicts between ad hoc EPCs. The major contributions of this model include the CONEX framework, collaboration mechanism and context transformation. The CONEX framework presents a formal characteri-sation and reconstruction of the structures of ad hoc EPCs based on a CONEX structure model and a CONEX grammar. It provides a formal specification for representing ad hoc EPCs including concept structure, classifier structure and mapping structure. The semantic conflicts in designing the concepts of ad hoc EPCs are resolved by a collaboration mecha-nism based on a semantic consistency model. The collaboration mechanism includes three key procedures: replicating unique concept identifiers and translating concept definitions be-tween common concepts of common EPCs; localising common concepts to local EPCs; and globalising local concepts to common EPCs. Users in the CONEX information model are not involved in any integration activities. They are provided with automatic and accurate concept exchange services through a mechanism of context transformation, which is designed based on an algorithm called Heterogeneous Concept Transformation. The separate integration of structures, concepts and contexts of ad hoc EPCs guarantees that the requirements of flexi-bility, evolvability and exactness of semantic integration have been met. Thirdly, the feasibility and features of the Collaborative Concept Exchange approach have been demonstrated in a prototype implementation that provides the services of collaborative concept design for semantic conflict resolution, and heterogeneous concept transformation for accurate and automatic concept exchange between ad hoc EPCs. A key contribution in the implementation level is the independent representation of the CONEX framework called XML PRODUCT MAP (XPM). XPM provides a feature of platform independence by con-forming to the standards of W3C XML, Simple Object Access Protocol and Web Services Description Language in both document specification and document transport. It is also a demonstration that the generic CONEX structure model and CONEX grammar can be imple-mented in any specific language such as XML for the particular scenarios of semantic integra-tion. With the aid of a collection of XPM document templates, two components called Con-cept Collaborator and Concept Transformer of the CONEX prototype are implemented to demonstrate how concepts are collaboratively designed to resolve semantic conflicts and how concepts are automatically and accurately exchanged between autonomous, heterogeneous and distributed ad hoc EPCs.

Existing electronic markets are fragmented in the sense that each is an information island. The interoperation of product information between them is difficult especially in semantics communication. This prevents the formation of global electronic markets and the lowering distribution cost through market globalisation. The traditional and contemporary ap-proaches of product standardisation and ontology mediation could solve the problem only if all markets could adopt the same product standards, or mediation systems could mediate all heterogeneous standards and markets without semantic conflicts. However, problems generally exist in adopting a universal standard or mediating all markets through existing mediation systems. A reflection of the issue is that there are millions of ad hoc electronic product catalogues (EPCs) situated in small and medium sized enterprises (SMEs), where each EPC is a semantic community, often not aware of standards and mediation systems due to its ad hoc nature. This thesis focuses on the semantic integration of autonomous ad hoc EPCs, which are semantically inconsistent with each other. Firstly, a novel Collaborative Concept Exchange (CONEX) approach is developed for the se-mantic integration of ad hoc EPCs. Using this approach, a PRODUCT MAP is first built based on the theories of semiotic analysis and market segmentation. It functions as an analytical framework to articulate ad hoc EPCs, and answers the questions: what are the general char-acteristics of ad hoc EPCs, what are their heterogeneous relations, and how they are unevenly distributed in fragmented electronic markets. Within this framework, an abstract representa-tion of ad hoc EPCs is proposed using the articulated elements that are simple and manipu-lable. Major contributions of this framework include: the models of the abstract representa-tion of ad hoc EPCs on their structures, concepts and contexts; the semantic integration conditions of heterogeneous ad hoc EPCs; and a ConexNet of market network topology that captures the characteristics of ad hoc EPCs that are unevenly distributed in fragmented elec-tronic markets. Secondly, a three-layer CONEX information model is proposed to integrate ad hoc EPCs based on the PRODUCT MAP, which provides a trichotomy of systems, designers and users. The strategy behind the model is the separation of structure from concept and context, and hence they can be independently managed to resolve semantic conflicts between ad hoc EPCs. The major contributions of this model include the CONEX framework, collaboration mechanism and context transformation. The CONEX framework presents a formal characteri-sation and reconstruction of the structures of ad hoc EPCs based on a CONEX structure model and a CONEX grammar. It provides a formal specification for representing ad hoc EPCs including concept structure, classifier structure and mapping structure. The semantic conflicts in designing the concepts of ad hoc EPCs are resolved by a collaboration mecha-nism based on a semantic consistency model. The collaboration mechanism includes three key procedures: replicating unique concept identifiers and translating concept definitions be-tween common concepts of common EPCs; localising common concepts to local EPCs; and globalising local concepts to common EPCs. Users in the CONEX information model are not involved in any integration activities. They are provided with automatic and accurate concept exchange services through a mechanism of context transformation, which is designed based on an algorithm called Heterogeneous Concept Transformation. The separate integration of structures, concepts and contexts of ad hoc EPCs guarantees that the requirements of flexi-bility, evolvability and exactness of semantic integration have been met. Thirdly, the feasibility and features of the Collaborative Concept Exchange approach have been demonstrated in a prototype implementation that provides the services of collaborative concept design for semantic conflict resolution, and heterogeneous concept transformation for accurate and automatic concept exchange between ad hoc EPCs. A key contribution in the implementation level is the independent representation of the CONEX framework called XML PRODUCT MAP (XPM). XPM provides a feature of platform independence by con-forming to the standards of W3C XML, Simple Object Access Protocol and Web Services Description Language in both document specification and document transport. It is also a demonstration that the generic CONEX structure model and CONEX grammar can be imple-mented in any specific language such as XML for the particular scenarios of semantic integra-tion. With the aid of a collection of XPM document templates, two components called Con-cept Collaborator and Concept Transformer of the CONEX prototype are implemented to demonstrate how concepts are collaboratively designed to resolve semantic conflicts and how concepts are automatically and accurately exchanged between autonomous, heterogeneous and distributed ad hoc EPCs.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Computing and Information Technology
Full Text

This thesis aims an exploratory evaluation of the Industry 4.0 (I4.0) impact on Portuguese Ornamental Stone (OS) firms’ response to the Threats resulting from the Building Information Modelling (BIM) procurement. The transition witnessed from the Third to the Fourth Industrial Age leads to the emergence of paradigms such as BIM, seeking efficiency in Architecture, Engineering and Construction (AEC) through a global approach and procurement oriented towards standardisable products and I4.0, where production comes to be supported by Cyber-Physical Systems (CPS). Integrated in the AEC supply chain, the OS sector shows Portugal to be the eighth country in OS trade worldwide, and the second per capita, with its competitiveness based on the products customization. BIM represents threats for its sustainability, particularly in firms of the Cluster Portugal Mineral Resources (CPMR). The literature review showed that Service Science (S-S) is an inter-disciplinary scientific field that combines Organisation with Tchnological Knowledge, with a view to categorizing, innovating and creating value for Service-Systems. Guided by the pragmatic paradigm and using the mixed methodology of parallel convergence, this research focuses on conceptualization of a Service Science Framework (Inovstone4.0), to which was applied a representative sample of CPMR companies. This Framework has allowed to measure the evolution of Key Concern Indicators (KCI) indexed to stakeholders’ concerns, when operations shifts from the current best practices to I4.0 operattions. From the results, it has been found significant relief of stakeholder’s concerns, regarding the time to deliver, costs, footprint and products conformity, when in BIM procurement context, the production evolves to I4.0, allowing to conclude that in technical terms, the impact of I4.0 on the threats arising from BIM procurement in CPMR tends to be positive; RESUMO: DESENVOLVIMENTO DA INDÚSTRIA 4.0 PELA SERVICE SCIENCE Modelo para a aumentar a Competitividade do Setor das Rochas Ornamentais Português em Contexto de Procurement BIM O objeto de estudo desta tese é explorar o potencial impacto da Industria 4.0 (I4.0) como resposta às ameaças resultantes da generalização do Building Information Modelling (BIM), nas empresas de Rochas Ornamentais (RO) portuguesas. Na transição da Terceira para a Quarta Era Industrial a que assistimos, emergem paradigmas como o BIM, que busca a eficiência na Arquitetura Engenharia e Construção (AEC) por via de uma abordagem global e de um modelo de procurement orientado para produtos standarizados e a I4.0, cuja produção passa a ser suportada por Cyber-Physical Systems (CPS). Integrado na cadeia de abastecimento da AEC, o setor das RO coloca Portugal como o oitavo país no comércio mundial de RO e segundo per capita, cuja competitividade provém da customização. Do procurement BIM, resultarão ameaças à sua sustentabilidade, nomeadamente nas empresas do Cluster Portugal Mineral Resources (CPMR). Da revisão de literatura verifica-se que a Service Science (S-S) é uma área científica interdisciplinar que combina organização e conhecimento tecnológico, com vista a categorizar, inovar e criar valor aos service-systems. Guiada pelo paradigma pragmatista e utilizando a metodologia mista paralela convergente, esta investigação centrou-se na conceptualização de um modelo S-S, que foi aplicado a uma amostra representativa das empresas do CPMR, permitiu medir de forma exploratória, a evolução das preocupações dos stakeholders, operacionalizadas por via de Key Concerns Indicators (KCI), quando as operações passam do estado atual, para o procurement BIM e produção I4.0. Dos resultados obtidos, verificou-se um alívio significativo das preocupações dos stakeholders quanto ao prazo de entrega, custo, sustentabilidade e qualidade dos produtos, quando as operações em contexto BIM evoluem para I4.0, permitindo concluir que em termos técnicos, o impacto da I4.0 sobre as ameaças resultantes do procurement BIM tende a ser positivo.

The world of smart materials has experienced a dramatic revolution in the last decades. Electro Active and Magneto Active Materials are some of the most iconic of these, among which, dielectric and magnetostrictive elastomers are becoming extremely popular due to their outstanding actuation capabilities, and in lesser degree, to their energy harvesting capabilities. A clear example illustrating these extraordinary capabilities has been reported in the experimental literature, which has shown unprecedented extreme electrically induced deformations for the most representative dielectric elastomer, namely the acrylic elastomer VHB 4910.This thesis is focused on the development of well-posed constitutive models for nonlinear electro-elasticity in scenarios characterised by extreme deformations and extreme electric fields. This fundamental objective represents the underlying ingredient for the novel variational and computational frameworks developed hereby in the context of electro-elasticity. Very remarkably, the similarity between the equations in both electro-elasticity and magneto-elasticity, enables the variational and computational frameworks developed to be extended to the latter scenario, characterised by magnetomechanical interactions. Despite the enormous interest of the experimental and computational scientific community, the definition of suitable constitutive models is still at its early stages for both electro and magneto active materials. In the more specic context of elasticity, considerable effort has been devoted to the denition of polyconvex energy functionals, which entail the most widely accepted constitutive restriction, namely the ellipticity or Legendre-Hadamard condition. This condition, strongly related to the material stability of the constitutive equations, ensures the well-posedness of the governing equations. An extension of the ellipticity condition to the context of nonlinear electro-elasticity and hence, magneto-elasticity, is proposed in this work, ensuring the well-posedness of the equations for the entire range of deformations and electric or magnetic fields. It is important to emphasise that in this work, the extension of the ellipticity condition to the field of electro-elasticity is exclusively based on material stability considerations. The energy functional encoding the constitutive response of the electro active material is defined according to a novel convex multi-variable representation in terms of an extended set of arguments which ensures material stability. The extended set of arguments, including those characterising the concept of polyconvexity in the more specic scenario of nonlinear elasticity, is further enriched with additional electromechanical entities. Unfortunately, proof of sequential weak lower semicontinuity of the proposed definition of multi-variable convexity is not provided in this work. This condition, and the additional requirement of appropriate coercivity conditions on the energy functional, would ensure the existence of minimisers. Nevertheless, although of extreme relevance and scientific interest, this topic is not in the scope of the thesis and could be the objective of further research.

This thesis developed a decision-support Bayesian network (BN) and complementary visualisation tool for image-guided radiotherapy (IGRT). These tools form the framework for a future decision-support system that will rapidly analyse cone beam computed tomography (CBCT) images and provide advice to clinicians whether to proceed with treatment delivery or if a pre-treatment intervention is required. Clinical experts completed an IGRT practice survey, which along with published and clinical data were used to develop the BN. The visualisation tool graphically summarises daily tumour and organ-at-risk variations routinely observed on CBCT images, which can result in incorrect targeting of the radiation fields.

L’arceau interventionnel est un système d’imagerie rayons X temps réel. Il dispose d’une option tomographique qui, grâce à une rotation de l’arceau autour du patient, permet d’acquérir des images en coupes dont la résolution en contraste est plus faible que celle des tomodensitomètres diagnostiques, rendant l’information clinique des tissus mous du cerveau inexploitable. Nous proposons un nouveau mode d’acquisition et de reconstruction tomographiques sur arceau interventionnel pour l’amélioration de la détection des faibles contrastes en imagerie interventionnelle des tissus mous de la tête. Afin d’émuler un filtre « bow-tie » (en nœud papillon), une double acquisition est envisagée. Les spécificités de la double acquisition imposent la conception d’un algorithme de reconstruction itérative dédié, incluant le filtre rampe dans l’énergie de minimisation. En bifurquant des approches par rétro-projection filtrée vers celles par filtration des rétro-projections, une méthode de reconstruction directe, alternative à la précédente, est proposée pour les acquisitions doubles. Pour une acquisition simple, la méthode est assurée de faire aussi bien que l’algorithme de rétro-projection filtrée quel que soit l’échantillonnage angulaire en géométrie planaire, et offre une approximation alternative à l’algorithme de Feldkamp-Davis-Kress en géométrie conique. Nous montrons qu’avec peu ou pas de modifications aux schémas précédents, les deux méthodes de reconstruction (itérative et directe) s’adaptent bien à la reconstruction de régions d’intérêt, à laquelle l’acquisition double reste étroitement liée à travers son acquisition tronquée
Interventional C-arm systems are real-time X-ray imaging systems, that can perform tomographic acquisitions by rotating the C-arm around the patient ; however, C-arm cone-beam computed tomography (CBCT) achieves a lower contrast resolution than diagnostic CT, which is necessary in order to benefit from the clinical information of soft tissues in the brain. We propose a new C-arm CBCT acquisition and reconstruction framework to increase low-contrast detection in brain soft-tissue imaging. In order to emulate a bow-tie filter, a dualrotation acquisition is proposed. To account for all the specificities of the dual-rotation acquisition, a dedicated iterative reconstruction algorithm is designed, that includes the ramp filter in the cost function. By switching from filtered backprojection (FBP) to backprojection-filtration (BPF) reconstruction methods, we propose an alternative, direct reconstruction method for dual-rotation acquisitions. For single-rotation acquisitions, the method ensures to perform as good as FBP with arbitrarily coarse angular sampling in planar geometries, and provides a different approximation from the Feldkamp-Davis-Kress (FDK) algorithm in the cone-beam geometry. Although we used it to emulate a virtual bow-tie, our dual-rotation acquisition framework is intrinsically related to region-of-interest (ROI) imaging through the truncated acquisition. With few or no modification of the proposed reconstruction methods, we successfully addressed the problem of ROI imaging in the context of dual-rotation acquisitions

Modern buildings increasingly include the usage of innovative materials aimed at improving sustainability and reducing the carbon footprint of the built environment. Phase Change Materials (PCMs) are one such group of novel materials which reduce building energy consumption. These materials are typically flammable and contained within wall linings yet there has been no detailed assessment of their fire performance. Current standard fire test methods provide means to compare similar materials but do not deliver knowledge on how they would behave in the event of a real fire. Thus, the aim of this thesis is to develop a novel testing framework to assess the behaviour of these materials in realistic fire scenarios. For PCMs, a flammability study is conducted in the bench-scale cone calorimeter to evaluate the fire risk associated with these materials. Then, micro-scale Thermogravimetric Analysis (TGA) is used to identify the fundamental chemical reactions to be able to confidently interpret the flammability results. Finally, intermediate-scale standard fire tests are conducted to evaluate the applicability of the bench-scale results to realistic fire scenarios. These take the form of modified Lateral Ignition and Flame spread Test (LIFT) and Single Burning Item (SBI) tests to understand flame spread and compartment fires respectively. Finally, a simplified method to combine this knowledge for use in building design is proposed. This method allows the balancing of potential energy benefits with quantified fire performance to achieve the specified goals of the designer. Hemp-lime insulation is a material which has also becoming increasingly popular in the drive towards sustainability. The porous nature of the material means that smouldering combustions are the dominant reaction mode but there is currently no standardised test method for this type of behaviour. Thus, hemp-lime materials also represent an unquantified risk. The work in this thesis defines a simple, accessible and economically viable bench-scale method for quantifying the fire risk associated with rigid porous materials. This is applicable for both downward opposed flow and upward forward flow smoulder propagation conditions. The behaviour is then interpreted using micro-scale thermogravimetric analysis to understand the underlying pyrolysis and oxidation reactions. Designers can utilise this framework to quantify the smouldering risk associated with hemp-lime materials to enable their usage in the built environment. The holistic fire risk assessment performed in this thesis has quantified the behaviour of PCMs and hemp-lime insulation applicable to realistic fire scenarios. The simplified design method empowers designers to be able to realise innovative buildings through fundamental understanding of the fire behaviour of these materials. The outcomes of this thesis allow designers to mitigate the fire risk associated with these materials and achieve optimised engineering solutions. Furthermore, the novel fire testing frameworks provide the economically viable means to assess the fire performance of future PCMs and hemp-lime products which ensures lasting relevance of this research in the future.

Lors des dernières décennies, la Séparation Aveugle de Sources (BSS) est devenue un outil de premier plan pour le traitement de données multi-valuées. L’objectif de ce doctorat est cependant d’étudier les cas grande échelle, pour lesquels la plupart des algorithmes classiques obtiennent des performances dégradées. Ce document s’articule en quatre parties, traitant chacune un aspect du problème: i) l’introduction d’algorithmes robustes de BSS parcimonieuse ne nécessitant qu’un seul lancement (malgré un choix d’hyper-paramètres délicat) et fortement étayés mathématiquement; ii) la proposition d’une méthode permettant de maintenir une haute qualité de séparation malgré un nombre de sources important: iii) la modification d’un algorithme classique de BSS parcimonieuse pour l’application sur des données de grandes tailles; et iv) une extension au problème de BSS parcimonieuse non-linéaire. Les méthodes proposées ont été amplement testées, tant sur données simulées que réalistes, pour démontrer leur qualité. Des interprétations détaillées des résultats sont proposées
During the last decades, Blind Source Separation (BSS) has become a key analysis tool to study multi-valued data. The objective of this thesis is however to focus on large-scale settings, for which most classical algorithms fail. More specifically, it is subdivided into four sub-problems taking their roots around the large-scale sparse BSS issue: i) introduce a mathematically sound robust sparse BSS algorithm which does not require any relaunch (despite a difficult hyper-parameter choice); ii) introduce a method being able to maintain high quality separations even when a large-number of sources needs to be estimated; iii) make a classical sparse BSS algorithm scalable to large-scale datasets; and iv) an extension to the non-linear sparse BSS problem. The methods we propose are extensively tested on both simulated and realistic experiments to demonstrate their quality. In-depth interpretations of the results are proposed

Wastewater discharged from industrial and agricultural activities contains relatively large amounts of toxic metal ions, especially including Cd(II), Cu(II), Pb (II), and Cr(VI). The removal of these pollutants is of great interest from both health and environmental perspectives. Arsenic contamination, generally associated with the geochemical environment, is a global threat due to its acute toxicity and carcinogenicity. The oxidation of different mineral species due to the redox conditions causes arsenic to become soluble and enter into the surrounding environment through drainage water. Conventional technologies for wastewater treatment and water purification such as precipitation, coagulation-flocculation, membrane processes, electrodialysis and ion-exchange are of limited utility due to their high cost, inefficiency in removing low metal concentrations, and sometimes also because they can generate large volumes of sludge. Adsorption is an attractive alternative due to its simplicity, its ability to remove trace amounts of metal ions, low cost, short operation time, and for the capacity for the material to be reused. Sorption processes are based on physical adsorption, chemical adsorption and ion exchange mechanisms. Among the different sorbent materials, activated carbon is the most widely used despite its high initial cost together with its regeneration costs. In the search for highly efficient, eco-friendly and economic adsorbents, agricultural waste and by-products from forest industries, including tea waste, coffee, hulls and shells from different nuts, sawdust, barks, cellulosic and lignocellulosic waste, corncobs, rice hulls, olive cake, fruit peels, sugar beet pulp, palm fruit bunch, maize leaves, among others, have been evaluated as biosorbents. They all typically have a good capacity to adsorb metal ions due to their porous structure and the fact that they have having carboxyl, hydroxyl, and other functional groups on their surface. The type of functional groups and chemical components of lignocellulosic materials makes them a good alternative adsorbent to treat contaminated effluents. The costs of these treatments will be low if the most suitable locally available biosorbents are used. Hence, in our case, we have evaluated lignocellulosic agroindustrial waste that is available in the Mediterranean region, such as olive stones and pine cones, as efficient biosorbents for the removal of toxic metal ions such as Pb(II), Cu(II), Cd(II) and Cr(VI)
Les aigües residuals generades per activitats agrícoles i industrials diverses contenen quantitats relativament grans d’ions metàl·lics tòxics, entre els què s’inclouen els ions Cd(II), Cu(II), Pb(II) i Cr(VI). L’eliminació d’aquests contaminants té un gran interès tant des de la perspectiva de la salut com del medi ambient. La contaminació per arsènic, generalment associada a l’entorn geoquímic, és un problema mundial a causa de la seva aguda toxicitat i carcinogenicitat. L'oxidació de diferents espècies minerals a causa de les condicions redox del medi aquàtic fa que l'arsènic sigui soluble i entri al medi ambient a través de l'aigua de drenatge. Les tecnologies convencionals per tractar les aigües residuals i depurar les aigües, com la precipitació, la coagulació-floculació, els processos de membrana, l’electrodiàlisi i l’intercanvi iònic, són d’utilitat limitada pel seu alt cost, la seva ineficiència en l’eliminació de baixes concentracions de metalls i, de vegades, també perquè poden generar grans volums de fangs. L’adsorció és un tractament alternatiu d’interès atesa la seva simplicitat, la seva capacitat d’eliminar ions metàl·lics a nivell de traces, el seu baix cost, curt temps d’operació i la potencial reutilització dels adsorbents. L’adsorció es pot basar en processos d’adsorció física, adsorció química i d’intercanvi iònic. Entre els diferents materials absorbents, el carbó actiu és el més utilitzat malgrat el seu preu elevat i els costos de regeneració. Com adsorbents alternatius, eficients i ecològics s’ha proposat l’ús de residus agrícoles i subproductes derivats de les indústries forestals, entre els que cal esmentar, entre d’altres, els residus de te i cafè, closques de diferents fruits secs, serradures, escorces, panotxes de blat de moro, pellofes d’arròs, pells de fruita, polpa de remolatxa sucrera, raïm de palma, fulles de blat de moro, i, en general, tot tipus de residus cel·lulòsics i lignocel·lulòsics. Molts d’aquests biosorbents han mostrat tenir una bona capacitat d’adsorció d’ions metàl·lics atesa la seva estructura porosa i la presència de grups funcionals carbonil, carboxil, hidroxil i d’altres tipus com amino o tiol en la superfície del biosorbent. . El tipus de grups funcionals i composició química dels materials lignocel·lulòsics fa que siguin una bona alternativa a altres adsorbents pel tractament d’efluents contaminats. Els costos d’aquests tractaments serien baixos si s’utilitzen els biosorbents adients disponibles localment. Per tant, en el nostre cas, s’han seleccionat residus agro-industrials lignocel·lulòsics disponibles a la regió mediterrània, com els pinyols d’oliva i les pinyes (estròbils), i s’ha avaluat la seva eficiència en l’eliminació d’ions metàl·lics tòxics com Pb(II), Cu(II), Cd(II) i Cr(VI)
Programa de Doctorat en Química

This study sets out to explore first person theatre as a means of opening the individual to the problems of contemporary capitalism and its increasing pervasion of the personal in an era of embeddedness enabled by networked pervasive technology. Firstly setting out key definitions and a theoretical analysis of the problems of being in the digital age in chapter 1, and then setting this against the history of interaction in performance in chapter 2. The study then goes on (in chapters 3-5) to investigate three key aspects of first person performance as personal-as-political; sound and the city, play and games, and interactive theatre. In the final chapter, The Umbrella Project develops a piece of first person theatre as practice, a method of investigation that is vital to a thesis that discusses politics, late capitalism, and the means to resist the message-sending of private interests as fundamentally only to be understood in practice. For this reason, too, chapters 3, 4 and 5 are supported by key case studies discussing other first person theatre practice. By placing the participant at the centre of the world-constituting process of theatre in the hot space between what is and what if this study suggests that first person theatre is able to open the contemporary individual to an inbetween where they might re-see, reflect and react to what is. To imagine and, if wished, act upon a what if. In an age of the disrupted near and far, the vanishing of the interface, of the false rhetoric of choice of personalisation , and the often false rhetoric of agency at the end of the era of broadcast, first person theatre offers the subject a route to individual agency, an understanding of the urban environment as construct, and to their relationship with the subjective other something which this thesis suggests is a personal-as-political practice to rival the Spectacle of late capitalism.

We present novel, efficient algorithms for solving extremely large optimization problems. A significant bottleneck today is that as the size of datasets grow, researchers across disciplines desire to solve prohibitively massive optimization problems. In this thesis, we present methods to compress optimization problems. The general goal is to represent a huge problem as a smaller problem or set of smaller problems, while still retaining enough information to ensure provable guarantees on solution quality and run time. We apply this approach to the following three settings.

First, we propose a framework for accelerating both linear program solvers and convex solvers for problems with linear constraints. Our focus is on a class of problems for which data is either very costly, or hard to obtain. In these situations, the number of data points m available is much smaller than the number of variables, n. In a machine learning setting, this regime is increasingly prevalent since it is often advantageous to consider larger and larger feature spaces, while not necessarily obtaining proportionally more data. Analytically, we provide worst-case guarantees on both the runtime and the quality of the solution produced. Empirically, we show that our framework speeds up state-of-the-art commercial solvers by two orders of magnitude, while maintaining a near-optimal solution.

Second, we propose a novel approach for distributed optimization which uses far fewer messages than existing methods. We consider a setting in which the problem data are distributed over the nodes. We provide worst-case guarantees on the performance with respect to the amount of communication it requires and the quality of the solution. The algorithm uses O(log(n+m)) messages with high probability. We note that this is an exponential reduction compared to the O(n) communication required during each round of traditional consensus based approaches. In terms of solution quality, our algorithm produces a feasible, near optimal solution. Numeric results demonstrate that the approximation error matches that of ADMM in many cases, while using orders-of-magnitude less communication.

Lastly, we propose and analyze a provably accurate long-step infeasible Interior Point Algorithm (IPM) for linear programming. The core computational bottleneck in IPMs is the need to solve a linear system of equations at each iteration. We employ sketching techniques to make the linear system computation lighter, by handling well-known ill-conditioning problems that occur when using iterative solvers in IPMs for LPs. In particular, we propose a preconditioned Conjugate Gradient iterative solver for the linear system. Our sketching strategy makes the condition number of the preconditioned system provably small. In practice we demonstrate that our approach significantly reduces the condition number of the linear system, and thus allows for more efficient solving on a range of benchmark datasets.

碩士
國立高雄師範大學
物理學系
91
This study is in two stages. The purpose of the first stage is to investigate the alternative framework on“Image formation by a convex lens”for 10th grade students. The purpose of the second stage is to diagnose the source of alternative frameworks that come from each. During the first stage of this study, a pen-paper tests was adopted as the method(Cronbach’s α = 0.89), and was given to 295 first grade students of girl’s senior high schools in Tainan county in 2001 academic year. The quantitative method was used to analyze the student’s responses in pen-paper tests. These were classified according to the conceptual construct of the alternative frameworks. During the second stage of this study, a semi-structured individual interview was adopted as the method designed by the researcher ad supra. this was given to 24 selected typical students that were representatives of each alternative framework in the first stage of this study. The qualitative method was used to analyse the student’s response during the interview and they were classified according to the alternative frameworks. According to the data analyses, The results indicated that the alternative framework on“Image formation by a convex lens”of 10th grade students can be classified into eight types as follows : 1、If part of the lens is covered, part of the image will vanish. 2、Light from an object travels in parallel rays. 3、Light from an object must pass through the center of a lens. 4、The three principal rays that travel from the object must pass through the lens to form the“image”. 5、“Image formation by a convex lens”and“Image formation by a pinhole”work on the same principle. 6、the center of a lens is more important than the circumference of the lens when“Image formation by a convex lens”is considered. 7、When a lens is divided into two separate regions, Two complete and individual images will be formed. 8、The image must“fit through”the aperture, so the measure and shape of the image will change with the aperture. According to the data analyses, The source of alternative frameworks can be classified into eight types as follows : 1、student’s naive concept. 2、student’s experience from daily life. 3、from the use of metaphors. 4、from confusion about the analogies. 5、student’s logical inferences from lineal cause and effect. 6、students do not establish a link between new knowledge and old belief systems. 7、knowledge gaps from bad teaching methods. 8、wrong figures or illustrations in the textbook.

This thesis focuses on the formulation and numerical implementation of a fully coupled continuum model for deformation-diffusion in linearized elastic solids. The mathematical model takes into account the affect of the deformation on the diffusion process, and the effect of the transport of an inert chemical species on the deformation of the solid. A robust computational framework is presented for solving the proposed mathematical model, which consists of coupled non-linear partial differential equations. It should be noted that many popular numerical formulations may produce unphysical negative values for the concentration, particularly, when the diffusion process is anisotropic. The violation of the non-negative constraint by these numerical formulations is not mere numerical noise. In the proposed computational framework we employ a novel numerical formulation that will ensure that the concentration of the diffusant be always non-negative, which is one of the main contributions of this thesis. Representative numerical examples are presented to show the robustness, convergence, and performance of the proposed computational framework. Another contribution is to systematically study the affect of transport of the diffusant on the deformation of the solid and vice-versa, and their implication in modeling degradation/healing of materials. It is shown that the coupled response is both qualitatively and quantitatively different from the uncoupled response.

Trust frameworks are of importance for increasingly mobile and dynamic enterprise ad-hoc systems to protect privacy, secure information and establish credibility. Trust enables humans and systems to accept risks and manage uncertainty. While various frameworks have been proposed, a common limitation is that they apply to closed systems where a central trust authority, a known inventory and the fair distribution of resources can be assumed. Open systems such as the Internet, cannot be considered under these assumptions. Enterprises increasingly consist of independently highly reprogrammable nodes and elements that are non-cooperative in nature. The original contribution of this work is that it identifies the need for and defines Emerging Systems as open, mobile ad-hoc systems consisting of highly-reprogrammable nodes within the enterprise, and shows that inherent limitations of these systems can be overcome by supporting proof that a non-cooperative game theoretical model is a suitable foundation for a Non-cooperative Programmable Open System Trust Framework (NPOST) for this new class of system. The framework’s underpinning theoretical model is defined by the formulation of mathematical constructs of a trust nomenclature and through rigorous application of non-cooperative game theoretical techniques to establish stability and (Nash) equilibrium. The framework is experimentally examined, with the results showing robustness under scale (small and large), partitioning (volatile and ephemeral topology) and with changing environmental influence, all conditions characteristic of Emerging Systems.