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Colloidal gold nanorods, iridescent beetles and breath figure templated assembly of ordered array of pores in polymer filmsSharma, Vivek 05 November 2008 (has links)
Water drops that nucleate and grow over an evaporating polymer solution exposed to a current of moist air remain noncoalescent and self-assemble into close packed arrays. The hexagonally close packed, nearly monodisperse drops, eventually evaporate away, leaving a polymer film, with ordered array of pores. Meanwhile, typical breath figures or dew that form when moist air contacts cold surfaces involve coalescence-assisted growth of highly polydisperse, disordered array of water drops.
This dissertation provides the first quantitative attempt aimed at the elucidation of the mechanism of the breath figure templated assembly of the ordered arrays of pores in polymer films. The creation and evolution of a population of close packed drops occur in response to the heat and mass fluxes involved in water droplet condensation and solvent evaporation. The dynamics of drop nucleation, growth, noncoalescence and self-assembly are modeled by accounting for various transport and thermodynamic processes. The theoretical results for the rate and extent of evaporative cooling and growth are compared with experiments. Further, the dissertation describes a rich array of experimental observations about water droplet growth, noncoalescence, assembly and drying that have not been reported in the published literature so far. The theoretical framework developed in this study allows one to rationalize and predict the structure and size of pores formed in different polymer-solvent systems under given air flow conditions.
While the ordered arrays of water drops present an example of dynamics, growth and assembly of spherical particles, the study on colloidal gold nanorods focuses on the behavior of rodlike particles. A comprehensive set of theoretical arguments based on the shape dependent hydrodynamics of rods were developed and used for centrifugation-assisted separation of rodlike particles from nanospheres that are typical byproducts of seed mediated growth of nanorods. Since the efficiency of shape separation is assessed using UV-Vis-NIR spectroscopy and transmission electron microscopy (TEM), the present dissertation elucidates the shape dependent parameters that affect the optical response and phase behavior of colloidal gold nanorods. The drying of a drop of colloidal gold nanorods on glass slides creates coffee ring like deposits near the contact line, which is preceded by the formation of a liquid crystalline phase. The assemblies of rods on TEM grids are shown to be the result of equilibrium and non-equilibrium processes, and the ordered phases are compared with two dimensional liquid crystals.
The methodology of pattern characterization developed in this dissertation is then used to analyze the structure of the exocuticle of iridescent beetle Chrysina gloriosa. The patterns were characterized using Voronoi analysis and the effect of curvature on the fractions on hexagonal order of tiles was determined. Further, these patterns were found to be analogous to the focal conic domains formed spontaneously on the free surface of a cholesteric liquid crystal.
In summary, the dissertation provides the crucial understanding required for the widespread use of breath figure templated assembly as a method for manufacturing porous films, that requires only a drop of polymer solution (dilute) and a whiff of breath! Further, the dissertation establishes the physical basis and methodology for separating and characterizing colloidal gold nanorods. The dissertation also suggests the basis for the formation and structure of tiles that decorate the exoskeleton of an iridescent beetle Chrysina gloriosa.
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Theories of non-linear systems : a paradigm for organizational thinkingMyburgh, Roche Francois 12 1900 (has links)
Thesis (MA)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The advent of the computer age has seen many fundamental changes in the
economics. The ease with which organisations can store and transmit information in
unprecedented quantities and speeds has changed the face of the economy as well
as the way in which organisations conduct their day to day operations. Information
has become the primary resource for organisational competitiveness and this has
seen an increasing drive for efficient information generation and management in an
economy that is interconnected on a global scale. The demand for better information
management practices is driven by the realisation that the global economy is
susceptible to sudden and unpredictable changes that can potentially have global
consequences. The more information organisations have at their disposal, the better
their chances are of remaining competitive and relevant in the global economy. The
informational economy confronts organisations with two very significant problems,
the first is information overload due to the sheer volume of information that is
available to them. The second problem is that despite the volume of available
information organisations still are not privy to all the information that is required to
lessen the impact of uncertainty that is so characteristic of the global economy.
Organisations therefore always run the' risk of becoming irrelevant if they do not
change constantly. This drive for continuous change and the dependence on
information has led some organisational theorists and economists to compare the
global economy and organisations to nonlinear systems found in nature. Examples of
nonlinear systems are living organisms, ecologies and solar systems. All of these
systems are characterised by high levels of interconnectedness and interdependence
among individual units within a shared environment, which they co-create. Nonlinear
systems are of particular interest to organisational theorists because these systems
process information about the environment to adapt in an unpredictable way to
unpredictable changes. Such systems are incredibly resilient because they are able
to learn and adapt to different conditions. Another notable aspect of nonlinear
systems is the clear structured and complex organisation that they exhibit in the
absence of centralised control mechanisms. Every unit has the liberty to experiment
with new designs and from the success of individual units an organised and stable
system emerges with a strong link between the success of individuals and the whole
system. The order that exists within nonlinear systems is known as self-organisation
because it is not superimposed but emerges instead in a spontaneous manner.
Nonlinear systems are therefore more than just the sum of their parts. The notion of
nonlinear systems and self-organisation has seen authors such as Stacey, Wheatley
and Senge develop new ideas about organisational development, leadership and
organisational strategic thinking. Their ideas are based on what is popularly known
as 'The New Science'. These ideas attempt to encourage organisations realise that
the global economy functions as a nonlinear system and that organisations stand a
better chance of success if they learn to understand the principles of nonlinear
systems and to utilise the inherent creative and organising characteristics of such
systems. / AFRIKAANSE OPSOMMING: Die aanvang van die rekenaar era het verskeie fundamentele veranderinge in
ekonomie mee gebring. Die gemak en snelheid waarmee organisasies informasie
kan stoor en versprei is ongekend en het terselfde tyd die voorkoms van die
ekonomie verander asook die wyse waarop organisasies op 'n daaglikse basis
funksioneer. Informasie het die belangrikste hulpbron geword vir organisasies in
terme van kompetering en dit het 'n groter dryfkrag vir doeltreffende informasie
ontginning en bestuur mee gebring in 'n ekonomie wat op 'n wereldwye skaal in
mekaar gevleg is. Die aanvraag vir beter informasie bestuur praktyke word gedryf deur die wete dat die wereld ekonomie vatbaar is vir skielike en onvoorspelbare
veranderinge wat potensieel 'n wereldwye impak kan he. Hoe meer informasie
organisasies tot hul beskikking het hoe beter is hul kans om relevant en kompeterend
te bly in die wereld ekonomie. Die informasie ekonomie konfronteer organisasies met
twee fundamentele probleme. Die eerste gevaar is dat organisasies oorlaai kan word
met informasie as gevolg van die absolute volume van beskikbare informasie. Die
tweede probleem spruit voort uit die feit dat ten spyte van die beskikbare informasie,
lei organisasies steeds aan 'n gebrek aan algehele informasie, organisasies kan dus
nooit toegang he tot al die informasie wat benodig word om die impak te verminder
van die onsekerheid wat so kenmerkend is van die wereld ekonomie. Organisasies
loop dus altyd die gevaar om irrelevant te raak as hulle nie konstant aanpas by nuwe
omstandighede nie. Hierdie soeke na konstante verandering en die afhanklikheid op
informasie het verskeie organisasie teoretici en ekonome daartoe gelei om 'n
vergelyking te tref tussen die wereld ekonomie en organisasies aan die een kant en
nie-Iiniere sisteme wat in die natuur voorkom. Voorbeelde van sulke sisteme sluit
lewende organismes, ekostelsels en sterre stelsels in. Die komponente van al hierdie
sisteme is op 'n komplekse wyse inmekaar geweef en interafhanklik op mekaar binne
die raamwerk van gemeenskaplike omgewing waarvoor hierdie komponente mede
verantwoordelik is. Nie-liniere sisteme is van besondere belang vir organisasie
teoretici omdat die betrokke sisteme informasie verwerk aangaande hul omgewing
om op 'n onvoorspelbare wyse aan te pas by onvoorspelbare veranderinge in die
omgewing. Sulke sisteme is uitsonderlik standvastig deurdat hulle kan leer en
aanpas by verskillende omstandighede. Nog
'n merkbare aspek van sulke sisteme is
die duidelik gestruktureerde en komplekse organisasie wat bestaan ten spyte van 'n
algehele gebrek aan gesentraliseerde beheer meganismes. Elke komponent is vry
om met 'n nuwe ontwerp te eksperimenteer en vanuit die sukses van die
komponente spruit die sukses van die sisteem. Die organisasie wat sigbaar is in nie-liniere
sisteme staan bekend as self-organisasie omdat dit nie voortspruit uit 'n
sentrale beheer meganisme nie maar instede spontaan onstaan as 'n gevolg van die
aksies van komponente. Nie-Iiniere sisteme het die potensiaal om meer te kan wees
as die somtotaal van hul komponente. Die beginsel van nie-liniere sisteme en selforganisasie
het skrywers soos Stacey, Wheatley en Senge daartoe gelei om nuwe
idees te ontwikkel rakende organisasie ontwikkeling, leierskap en strategiese
beplanning in organisasies. Hierdie idees is gegrond in wat algemeen bekend staan
as 'The New Science'. Die idees van hierdie skrywers is gemik daarop om
organisasies aan te moedig om raak te sien dat die wereld ekonomie soos 'n nie-liniere
sisteem funksioneer en dat organisasies as sulks 'n beter kans staan om sukses
te behaal as hulle sou leer om die beginsels van nie-liniere sisteme te begryp en die
inherente kreatiewe en organiserings eienskappe van sulke sisteme uit te buit.
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GCAD - Um modelo conceitual para gerenciamento e controle autônomo e distribuído para sistemas industriais automatizados.Pacheco, Luciana de Almeida January 2011 (has links)
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Previous issue date: 2011 / Em sistemas industriais automatizados, a inatividade provocada pela escassez não planejada de recursos, ou por falhas de processo, tem grande influência no desempenho dos sistemas por conta das descontinuidades e instabilidades geradas. Sistemas de controle distribuídos e autônomos podem ajudar a lidar com esses tipos de problemas devido à melhoria de desempenho possibilitada. Entretanto, aspectos relativos à segurança e ao tempo de resposta devem ser bem tratados nesses sistemas devido aos riscos envolvidos (humanos, financeiros e ambientais). A proposta de sistemas autônomos e distribuídos visa a que decisões de controle sejam tomadas mais próximas do objeto controlado, reduzindo assim o tempo de atuação no processo e sistematizando algumas decisões, antes tomadas de forma empírica. Consequentemente, se espera aumentar a disponibilidade e a continuidade do processo, bem como garantir os aspectos de confiabilidade. Entretanto, quando tais sistemas se tornam mais autônomos e distribuídos, podem tender ao comportamento global caótico, caso suas interações não estejam bem definidas. Assim, é importante que seja avaliado e dimensionado o acoplamento entre os sistemas autônomos relacionados. O grau de inteligência de um sistema pode variar de uma entidade completamente controlada a entidades completamente autônomas. O primeiro nível de inteligência é verificado quando um sistema é capaz de gerenciar suas próprias informações, obtidas por meio de sensores e demais técnicas e dispositivos, e não somente manipular informações. Em um segundo nível, o sistema pode notificar o seu gestor quando há um problema. Em um terceiro nível, o sistema já é capaz de tomar decisões e se autogerenciar, mesmo sem intervenção externa. Neste caso, o sistema tem controle total sobre suas tarefas e não há nenhum controle externo a ele. A alternativa proposta pelo GCAD visa a que Sistemas Industriais Automatizados atinjam até o terceiro nível de inteligência, sendo que intervenções externas podem ser admitidas nos casos em que uma ação puramente local e autônoma de fato não é recomendável ou não é possível, por exemplo, havendo necessidade de substituição de equipamentos ou dispositivos. O GCAD propõe um módulo de controle inteligente instanciado predominantemente em nível local que visa a permitir que cada Sistema Industrial Automatizado, distribuído em células, tome decisões críticas de uma forma autônoma. Adicionalmente, um módulo remoto deve gerenciar situações mais complexas que estão além da capacidade de decisão ou atuação do sistema de controle local. O modelo proposto visa a permitir ajustes automáticos e autônomos no sistema, a fim de melhorar seu desempenho, e prevenir ou tratar as falhas inesperadas,assegurando a continuidade da operação. / Salvador
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A second-order cybernetic explanation for the existence of network direct selling organisations as self-creating systemsDavis, Corne 18 August 2011 (has links)
Network Direct Selling Organisations (NDSOs) exist in more than 50 countries and have more than 74 million members. The most recent statistical information reveals that the vast majority of members do not earn significant income. Criticism of these organisations revolves around the ethicality of consumption, the commercialisation of personal relationships, and the exploitation of unrealistic expectations. This study aims to explore how communication creates networks that sustain an industry of this kind despite the improbability of its existence.
The study commences with a description of NDSOs from historical, operational, tactical, and strategic perspectives. Given the broader context created by the global presence of this industry, cybernetics has been selected as a meta-theoretical perspective for the study of communication. The more recent development of second-order cybernetics and social autopoiesis are introduced to communication theory as a field. Niklas Luhmann‟s new social theory of communication is assessed and applied in relation to existing communication theory.
New conceptual models are developed to explore communication as the unity of the synthesis of information, utterance, understanding, and expectations as selections that occur both consciously and unconsciously, intentionally and unintentionally. These models indicate the multiplexity of individual and social operationally closed, yet informationally open systems, and they are used here to provide a systemic and coherent alternative to orthodox communication approaches to the study of organisations. The study adopts a constructivist epistemological stance and propounds throughout the necessity of further interdisciplinary collaboration.
The study concludes that individuals are composite unities of self-creating systems, and they co-create social systems by self-creating and co-creating meaning. Meaning is described as the continuous virtualisation and actualisation of potentialities that in turn coordinate individual and social systems‟ actions. A communication process flow model is created to provide a theoretical explanation for the existence of NDSOs as self-creating systems. The study aims to show that communication has arguably become the most pervasive discipline as a result of the globally interactive era. It is shown that second-order cybernetics and social autopoiesis raise several further questions to be explored within communication theory as a field. / Communication, first-order cybernetics, second-order cybernetics, Complexity and complex systems, autopoiesis, self-reference, recursivity, operational closure, system boundaries, Network Direct Selling Organisations / Communication / D. Litt. et Phil. (Communication)
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Vérification formelle des systèmes multi-agents auto-adaptatifs / Formal verification of self-adaptive multi-agent systemsGraja, Zaineb 15 September 2015 (has links)
Un des défis majeurs pour le développement des Systèmes Multi-Agents (SMA) auto-organisateurs est de garantir la convergence du système vers la fonction globale attendue par un observateur externe et de garantir que les agents sont capables de s'adapter face aux perturbations. Dans la littérature, plusieurs travaux se sont basés sur la simulation et le model-checking pour analyser les SMA auto-organisateurs. La simulation permet aux concepteurs d'expérimenter plusieurs paramètres et de créer certaines heuristiques pour faciliter la conception du système. Le model-checking fournit un support pour découvrir les blocages et les violations de propriétés. Cependant, pour faire face à la complexité de la conception des SMA auto-organisateurs, le concepteur a également besoin de techniques qui prennent en charge non seulement la vérification, mais aussi le processus de développement lui-même. En outre, ces techniques doivent permettre un développement méthodique et faciliter le raisonnement sur divers aspects du comportement du système à différents niveaux d'abstraction. Dans cette thèse, trois contributions essentielles ont été apportées dans le cadre du développement et la vérification formelle des SMA auto-organisateurs: une formalisation à l'aide du langage B-événementiel des concepts clés de ces systèmes en trois niveaux d'abstraction (micro, méso et macro), une expérimentation d'une stratégie de raffinement descendante pour le développement des SMA auto-organisateurs et la proposition d'un processus de raffinement ascendant basé sur des patrons de raffinement. / A major challenge for the development of self-organizing MAS is to guarantee the convergence of the system to the overall function expected by an external observer and to ensure that agents are able to adapt to changes. In the literature, several works were based on simulation and model-checking to study self-organizing MAS. The simulation allows designers to experiment various settings and create some heuristics to facilitate the system design. Model checking provides support to discover deadlocks and properties violations. However, to cope with the complexity of self-organizing MAS, the designer also needs techniques that support not only verification, but also the development process itself. Moreover, such techniques should support disciplined development and facilitate reasoning about various aspects of the system behavior at different levels of abstraction. In this thesis, three essential contributions were made in the field of formal development and verification of self-organizing MAS: a formalization with the Event-B language of self-organizing MAS key concepts into three levels of abstraction, an experimentation of a top-down refinement strategy for the development of self-organizing MAS and the definition of a bottom-up refinement process based on refinement patterns.
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Análise das configurações da Regional CIC: um estudo de caso do comportamento emergenteBazan, Luciana Borges 24 August 2012 (has links)
Compreender o comportamento emergente nos territórios urbanos é fundamental
para estudar e direcionar com maior eficiência as políticas públicas. Considerando que as emergências urbanas são elementos presentes no cotidiano das cidades não é possível ao Estado não levá-las em conta ao formular suas ações púbicas. Tomando como premissa que a sociedade é um corpo vivo, onde cada órgão cumpre uma função, busca-se o caminho para instrumentalizar ações políticas adequadas às emergências urbanas. Assim, o objetivo do estudo é refletir sobre o comportamento emergente a partir do estudo de caso da Regional CIC, levando em conta os aspectos do planejamento político e aqueles relativos à auto-organização dos espaços e territórios. O estudo, em seus métodos de pesquisa, é exploratóriodescritivo, com delineamento analítico e configurando-se como estudo de caso. A análise realizada é qualitativa, buscando a relação do caso concreto descrito com a literatura estudada e o universo de pesquisa corresponde à cidade de Curitiba, tendo como amostragem direta a Regional CIC. Por meio do estudo literário levantou-se que o comportamento emergente nos espaços urbanos é uma constante, especialmente em cidades ou territórios em constante desenvolvimento como é o caso da cidade de Curitiba – PR. Os sistemas emergentes são resultado de processos que envolvem ordem e desordem e auto-organização, tendo os sistemas de redes como elemento para sua constituição. As emergências urbanas, seguindo os conceitos emergentistas, não podem ser previstas ou planejadas, surgem a partir de um processo auto-organizado, de baixo para cima, onde níveis inferiores produzem novas propriedades com características complexas. Ao analisar a criação da Regional CIC percebe-se que diversos elementos emergentes estão presentes, tendo destaque os seguintes: Criação da Cidade industrial de Curitiba, regionalização e territorialização, desterritorialização (desmembramento do bairro), redes setoriais planejadas ou não e interorganizacionais e ênfase aos aspectos humanos e éticos. Percebe-se que as políticas públicas analisadas têm elementos emergentes, pois são descentralizas, trabalham em sistema de redes, trocam informações constantes com a comunidade e procuram influenciar, sem controlar, os territórios em desenvolvimento. Pode-se concluir que as políticas públicas não devem buscar o controle dos movimentos urbanos e dos processos emergentes, mas incentivar a criatividade e a capacidade de auto-organização dos grupos sociais, sendo ela mesma, um dos componentes dos sistemas urbanos emergentes. / Understanding the emergent behavior in urban areas is essential to study more
efficiently and drive public policy. Whereas the urban emergencies are elements
present in the daily life of cities is not possible for the state not take them into
account when formulating their actions pubic area. Taking as its premise that society
is a living body, where each agency fulfills a function, we seek to equip the way for
appropriate policy actions to urban emergencies. The objective of this study is to reflect on the emergent behavior from the case study of the Regional CIC, taking into
account aspects of planning policy and those related to self-organization of spaces
and territories. The study, in its methods of research is exploratory and descriptive,
analytical and design configured as a case study. The analysis is qualitative, seeking
the relationship of the case described in the literature studied and the universe of
research is the city of Curitiba, with the direct sampling the Regional CIC. Through
the literary study arose that the emergent behavior in urban areas is a constant,
especially in cities or territories in constant development as is the case of Curitiba - PR. The emerging systems are the result of processes that involve order and
disorder and self-organization, and network systems as an element in its constitution.
The urban emergencies, following the emergentist concepts, can not be predicted or
planned, arise from a self-organizing process, from the bottom up, which produce
lower levels of new properties with complex traits. By analyzing the creation of the
Regional CIC realizes that many emerging elements are present, and highlighted the
following: Creation of the Industrial City of Curitiba, regionalization and
territorialization, deterritorialization (dismemberment of the neighborhood), sectoral
networks planned or unplanned, and interorganizational and emphasis to human and
ethical aspects. It is felt that public policies have analyzed emerging elements
because they are descentralizas, working in the system of networks, exchange
information in the community and seek to influence, not control, the territories in
development. It can be concluded that public policy should not seek control of urban
movements and emerging processes, but encourage creativity and self-organization
of social groups, being herself, one of the components of urban systems emerging.
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Agrupamento de dados baseado em comportamento coletivo e auto-organização / Data clustering based on collective behavior and self-organizationRoberto Alves Gueleri 18 June 2013 (has links)
O aprendizado de máquina consiste de conceitos e técnicas que permitem aos computadores melhorar seu desempenho com a experiência, ou, em outras palavras, aprender com dados. Um dos principais tópicos do aprendizado de máquina é o agrupamento de dados que, como o nome sugere, procura agrupar os dados de acordo com sua similaridade. Apesar de sua definição relativamente simples, o agrupamento é uma tarefa computacionalmente complexa, tornando proibitivo o emprego de algoritmos exaustivos, na busca pela solução ótima do problema. A importância do agrupamento de dados, aliada aos seus desafios, faz desse campo um ambiente de intensa pesquisa. Também a classe de fenômenos naturais conhecida como comportamento coletivo tem despertado muito interesse. Isso decorre da observação de um estado organizado e global que surge espontaneamente das interações locais presentes em grandes grupos de indivíduos, caracterizando, pois, o que se chama auto-organização ou emergência, para ser mais preciso. Os desafios intrínsecos e a relevância do tema vêm motivando sua pesquisa em diversos ramos da ciência e da engenharia. Ao mesmo tempo, técnicas baseadas em comportamento coletivo vêm sendo empregadas em tarefas de aprendizado de máquina, mostrando-se promissoras e ganhando bastante atenção. No presente trabalho, objetivou-se o desenvolvimento de técnicas de agrupamento baseadas em comportamento coletivo. Faz-se cada item do conjunto de dados corresponder a um indivíduo, definem-se as leis de interação local, e então os indivíduos são colocados a interagir entre si, de modo que os padrões que surgem reflitam os padrões originalmente presentes no conjunto de dados. Abordagens baseadas em dinâmica de troca de energia foram propostas. Os dados permanecem fixos em seu espaço de atributos, mas carregam certa informação a energia , a qual é progressivamente trocada entre eles. Os grupos são estabelecidos entre dados que tomam estados de energia semelhantes. Este trabalho abordou também o aprendizado semissupervisionado, cuja tarefa é rotular dados em bases parcialmente rotuladas. Nesse caso, foi adotada uma abordagem baseada na movimentação dos próprios dados pelo espaço de atributos. Procurou-se, durante todo este trabalho, não apenas propor novas técnicas de aprendizado, mas principalmente, por meio de muitas simulações e ilustrações, mostrar como elas se comportam em diferentes cenários, num esforço em mostrar onde reside a vantagem de se utilizar a dinâmica coletiva na concepção dessas técnicas / Machine learning consists of concepts and techniques that enable computers to improve their performance with experience, i.e., enable computers to learn from data. Data clustering (or just clustering) is one of its main topics, which aims to group data according to their similarities. Regardless of its simple definition, clustering is a complex computational task. Its relevance and challenges make this field an environment of intense research. The class of natural phenomena known as collective behavior has also attracted much interest. This is due to the observation that global patterns may spontaneously arise from local interactions among large groups of individuals, what is know as self-organization (or emergence). The challenges and relevance of the subject are encouraging its research in many branches of science and engineering. At the same time, techniques based on collective behavior are being employed in machine learning tasks, showing to be promising. The objective of the present work was to develop clustering techniques based on collective behavior. Each dataset item corresponds to an individual. Once the local interactions are defined, the individuals begin to interact with each other. It is expected that the patterns arising from these interactions match the patterns originally present in the dataset. Approaches based on dynamics of energy exchange have been proposed. The data are kept fixed in their feature space, but they carry some sort of information (the energy), which is progressively exchanged among them. The groups are established among data that take similar energy states. This work has also addressed the semi-supervised learning task, which aims to label data in partially labeled datasets. In this case, it has been proposed an approach based on the motion of the data themselves around the feature space. More than just providing new machine learning techniques, this research has tried to show how the techniques behave in different scenarios, in an effort to show where lies the advantage of using collective dynamics in the design of such techniques
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Proactive university library book recommender systemMekonnen, Tadesse Zewdu January 2021 (has links)
M. Tech. (Department of Information Communication Technology, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Too many options on the internet are the reason for the information overload problem to obtain relevant information. A recommender system is a technique that filters information from large sets of data and recommends the most relevant ones based on people‟s preferences. Collaborative and content-based techniques are the core techniques used to implement a recommender system. A combined use of both collaborative and content-based techniques called hybrid techniques provide relatively good recommendations by avoiding common problems arising from each technique. In this research, a proactive University Library Book Recommender System has been proposed in which hybrid filtering is used for enhanced and more accurate recommendations. The prototype designed was able to recommend the highest ten books for each user. We evaluated the accuracy of the results using Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE). A measure value of 0.84904 MAE and 0.9579 RMSE found by our system shows that the combined use of both techniques gives an improved prediction accuracy for the University Library Book Recommender System.
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<b>A MOBILE, MODULAR,AND SELF-RECONFIGURABLE ROBOTIC SYSTEM WITH MORPHABILITY</b><b>, </b><b>and</b><b> self-reconfigurable robotic system with morphability</b>Lu Anh Tu Vu (17612166) 15 December 2023 (has links)
<p dir="ltr">This paper aims to gain a deep understanding of up-to-date research and development on modular self-reconfigurable robots (MSRs) through a thorough survey of market demands and published works on <i>design methodologies</i>, <i>system integration</i>, <i>advanced controls</i>, and <i>new applications</i>. Some limitations of existing mobile MSR are discussed from the reconfigurability perspective of mechanical structures, and a novel MSR system is proposed to address the identified limitations of existing MSRs. The comprehensive set of <i>Functional Requirements</i> (FRs) of MSRs is discussed, from which the mechanical designs of MSR were created, and the system was prototyped and built for testing. Three main innovations of the designed modules for MSR are to (1) share torque power, (2) customize the size for a given task, and (3) have a low number of actuated motors while still maintain a motion with high <i>Degrees of Freedom</i> (DoF) to overcome the constraints by the power capacities of individual motors; this helps to increase reconfigurability, reduce cost, and reduce the size of conventional MSRs.</p>
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'n Konstruktivistiese beskrywing van veranderende persepsies in 'n welsynsorganisasieCommerford, Sophia Elizabeth Jacoba 11 1900 (has links)
Text in Afrikaans / Hierdie studie kontrasteer die Newtoniaanse denkwyse en die konstruktivisme as
vertrekpunt. Die beginsels van reduksionisme, neutraliteit en liniere oorsaaklikheid
waarop die Newtoniaanse denke gefundeer is, word gekontrasteer met die sirkulariteit
en non-objektiwiteit van interveiwante elemente binne die lewende sisteem.
Die verskille in aannames van personeel van 'n welsynsvereniging word ondersoek aan
die hand van observasie van prosesse van veranderende denke wat oor 'n periode
ontwikkel het. Die proses van verandering word aan die hand van 'n gevallestudie
bespreek.
Binne die veranderende denke, is erkenning verleen aan die sistemiese orientasie
waar die interaktiewe intervetwantskap van die elemente binne die sisteem ter sprake
raak. Die lewende sisteem en die kenmerke van outonomie, outopo"ise, organisasie en
struktuur word binne die filosofie van konstruktivisme bespreek. Uit hierdie filosofie
evolueer 'n proses waar binne realiteite geskep word, konsensus binne die sisteem
verkry word, en die organisasie van die lewende sisteem reflekteer word / This study focusses on the contrasting thinking patterns of Newtonian thinking and
constructivism. The principles of reductionism, neutrality and linear causality on which
Newtonian thinking is grounded are compared with circular processes and non
objectivity of interrelated elements that are to be found in living systems.
The differences in assumptions of personnel in a welfare organisation are investigated
through observation of changing processes of thinking that evolved over a period of
time. The process of change is discussed by way of a case study.
Recognition is given to the systemic orientation where the interactive interrelatedness
of elements within the system evolved within changing patterns of thinking. The living
system and characteristics of autonomy, autopoiesis, organisation and structure are
discussed from a philosophy of constructivism. From this philosophy evolved a process
in which realities were created, consensus was reached within the system, and the
organisation of the living system was reflected. / Social Work / M.A. (Sosiale Wetenskappe(Geestesgesondheid))
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