Dissertations / Theses: 'Natural and artificial ageing'

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Nguyen, Thanh Hoi. "Vieillissement artificiel et vieillissement naturel en ambiance tropicale de composites modèles époxy/verre : approche nanoscopique de l'étude des interphases." Phd thesis, Toulon, 2013. http://tel.archives-ouvertes.fr/tel-00942583.

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Un composite époxy/fibre de verre élaboré à partir de matériaux simplifiés a été soumis en parallèle à du vieillissement artificiel (UV et thermohydrique) et à du vieillissement naturel (climat tropical humide). Une étude des matériaux (résine seule et composite) à travers un large panel de techniques de caractérisation physico-chimiques, mécaniques et de moyens d'observation (MEB, AFM) a permis d'identifier clairement la structure, la morphologie et les principales propriétés du réseau époxy-amine de l'état initial. Une caractérisation systématique des échantillons par couches de 20 microns d'épaisseur a permis, en particulier, d'identifier un gradient de structure et de propriétés dans les 200 premiers microns à la surface des plaques de résine et de composite. Ce gradient est attribué à l'évaporation du durcisseur amine lors de l'élaboration des matériaux. Dans les plaques de composites, le DMA ainsi que l'AFM ont permis de mettre en évidence une zone d'interphase autour des fibres pour laquelle le réseau époxy-amine présente des caractéristiques différentes de celles de la résine en masse.La même méthodologie a été adoptée pour suivre l'évolution de ces matériaux lors des vieillissements artificiels et naturels.Les études séparées des vieillissements UV et thermohydrique ont permis de mettre en évidence les altérations chimiques et physico-chimiques de la matrice seule d'une part, et des interphases fibres/matrice d'autre part. Le vieillissement photochimique se montre le plus dégradant pour la surface des plaques, alors que les effets du vieillissement thermohydrique sont principalement observés au niveau des interfaces fibres/matrice dans les composites. Dans les deux cas également, nous pouvons proposer des mécanismes simplifiés de dégradation de la résine époxy-amine.Enfin, les résultats de caractérisation après le vieillissement naturel nous permettent de faire des corrélations avec les vieillissements artificiels et de pointer les effets prépondérants des deux paramètres de vieillissement, ainsi que d'avancer un facteur d'accélération.

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Panesar, Kulvinder. "Natural language processing (NLP) in Artificial Intelligence (AI): a functional linguistic perspective." Vernon Press, 2020. http://hdl.handle.net/10454/18140.

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Yes
This chapter encapsulates the multi-disciplinary nature that facilitates NLP in AI and reports on a linguistically orientated conversational software agent (CSA) (Panesar 2017) framework sensitive to natural language processing (NLP), language in the agent environment. We present a novel computational approach of using the functional linguistic theory of Role and Reference Grammar (RRG) as the linguistic engine. Viewing language as action, utterances change the state of the world, and hence speakers and hearer’s mental state change as a result of these utterances. The plan-based method of discourse management (DM) using the BDI model architecture is deployed, to support a greater complexity of conversation. This CSA investigates the integration, intersection and interface of the language, knowledge, speech act constructions (SAC) as a grammatical object, and the sub-model of BDI and DM for NLP. We present an investigation into the intersection and interface between our linguistic and knowledge (belief base) models for both dialogue management and planning. The architecture has three-phase models: (1) a linguistic model based on RRG; (2) Agent Cognitive Model (ACM) with (a) knowledge representation model employing conceptual graphs (CGs) serialised to Resource Description Framework (RDF); (b) a planning model underpinned by BDI concepts and intentionality and rational interaction; and (3) a dialogue model employing common ground. Use of RRG as a linguistic engine for the CSA was successful. We identify the complexity of the semantic gap of internal representations with details of a conceptual bridging solution.

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au, os goh@murdoch edu, and Ong Sing Goh. "A framework and evaluation of conversation agents." Murdoch University, 2008. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20081020.134601.

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This project details the development of a novel and practical framework for the development of conversation agents (CAs), or conversation robots. CAs, are software programs which can be used to provide a natural interface between human and computers. In this study, conversation refers to real-time dialogue exchange between human and machine which may range from web chatting to on-the-go conversation through mobile devices. In essence, the project proposes a smart and effective communication technology where an autonomous agent is able to carry out simulated human conversation via multiple channels. The CA developed in this project is termed Artificial Intelligence Natural-language Identity (AINI) and AINI is used to illustrate the implementation and testing carried out in this project. Up to now, most CAs have been developed with a short term objective to serve as tools to convince users that they are talking with real humans as in the case of the Turing Test. The traditional designs have mainly relied on ad-hoc approach and hand-crafted domain knowledge. Such approaches make it difficult for a fully integrated system to be developed and modified for other domain applications and tasks. The proposed framework in this thesis addresses such limitations. Overcoming the weaknesses of previous systems have been the key challenges in this study. The research in this study has provided a better understanding of the system requirements and the development of a systematic approach for the construction of intelligent CAs based on agent architecture using a modular N-tiered approach. This study demonstrates an effective implementation and exploration of the new paradigm of Computer Mediated Conversation (CMC) through CAs. The most significant aspect of the proposed framework is its ability to re-use and encapsulate expertise such as domain knowledge, natural language query and human-computer interface through plug-in components. As a result, the developer does not need to change the framework implementation for different applications. This proposed system provides interoperability among heterogeneous systems and it has the flexibility to be adapted for other languages, interface designs and domain applications. A modular design of knowledge representation facilitates the creation of the CA knowledge bases. This enables easier integration of open-domain and domain-specific knowledge with the ability to provide answers for broader queries. In order to build the knowledge base for the CAs, this study has also proposed a mechanism to gather information from commonsense collaborative knowledge and online web documents. The proposed Automated Knowledge Extraction Agent (AKEA) has been used for the extraction of unstructured knowledge from the Web. On the other hand, it is also realised that it is important to establish the trustworthiness of the sources of information. This thesis introduces a Web Knowledge Trust Model (WKTM) to establish the trustworthiness of the sources. In order to assess the proposed framework, relevant tools and application modules have been developed and an evaluation of their effectiveness has been carried out to validate the performance and accuracy of the system. Both laboratory and public experiments with online users in real-time have been carried out. The results have shown that the proposed system is effective. In addition, it has been demonstrated that the CA could be implemented on the Web, mobile services and Instant Messaging (IM). In the real-time human-machine conversation experiment, it was shown that AINI is able to carry out conversations with human users by providing spontaneous interaction in an unconstrained setting. The study observed that AINI and humans share common properties in linguistic features and paralinguistic cues. These human-computer interactions have been analysed and contributed to the understanding of how the users interact with CAs. Such knowledge is also useful for the development of conversation systems utilising the commonalities found in these interactions. While AINI is found having difficulties in responding to some forms of paralinguistic cues, this could lead to research directions for further work to improve the CA performance in the future.

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Ray, Arijit. "The Art of Deep Connection - Towards Natural and Pragmatic Conversational Agent Interactions." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/78335.

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As research in Artificial Intelligence (AI) advances, it is crucial to focus on having seamless communication between humans and machines in order to effectively accomplish tasks. Smooth human-machine communication requires the machine to be sensible and human-like while interacting with humans, while simultaneously being capable of extracting the maximum information it needs to accomplish the desired task. Since a lot of the tasks required to be solved by machines today involve the understanding of images, training machines to have human-like and effective image-grounded conversations with humans is one important step towards achieving this goal. Although we now have agents that can answer questions asked for images, they are prone to failure from confusing input, and cannot ask clarification questions, in turn, to extract the desired information from humans. Hence, as a first step, we direct our efforts towards making Visual Question Answering agents human-like by making them resilient to confusing inputs that otherwise do not confuse humans. Not only is it crucial for a machine to answer questions reasonably, it should also know how to ask questions sequentially to extract the desired information it needs from a human. Hence, we introduce a novel game called the Visual 20 Questions Game, where a machine tries to figure out a secret image a human has picked by having a natural language conversation with the human. Using deep learning techniques like recurrent neural networks and sequence-to-sequence learning, we demonstrate scalable and reasonable performances on both the tasks.
Master of Science

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Datsiou, Kyriaki Corinna. "Design and performance of cold bent glass." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/269408.

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The demand for flat glass is high and increasing significantly in the building industry as a direct result of architectural requirements for lightness, transparency and natural light. Current architectural trends require glass in curvilinear forms for smooth free-form façades. Two principal challenges arise from this: to cost-effectively produce the desired curvature and; to ensure its safe performance after exposure to ageing. The recent availability of high strength glass provides an opportunity to address the first challenge by developing cold bent glass. Cold bending involves the straining of relatively thin glass components, at ambient temperatures, and is a low energy and cost effective manner of creating curvilinear forms. However, cold bending is not yet widely established as a reliable method. The aim of this thesis is to develop the understanding of cold bent glass during the bending process and to evaluate its post-ageing performance. This thesis, firstly, investigates the mechanical response of monolithic glass plates during the cold bending process. The stability of cold bent glass is investigated experimentally by bending it in double curved anticlastic shapes. A parametric numerical analysis involves different boundary conditions, geometrical plate characteristics and bending parameters. The principal outcome is that a local instability, now termed cold bending distortion, occurs when certain displacement limits are exceeded and could degrade the optical quality of the glass. An evaluation procedure is also formulated to set limits and aid designers/manufacturers to predict the mechanical response and the optical quality of the glass. Cold bent glass is subjected to permanent bending stresses throughout its service life and therefore, its strength degradation after ageing needs to be quantified. Analytical, experimental and numerical investigations are undertaken in this thesis to identify the most effective method for estimating glass strength (evaluation of destructive tests, required number of specimens, statistical analysis methods and sub-critical crack growth). The limited availability of naturally aged toughened glass and the absence of a reliable ageing standard impede the evaluation of its aged performance. Therefore, a parametric experimental investigation of artificial ageing methods on glass is undertaken in this thesis. A procedure for the evaluation of the strength of aged glass is finally, formulated to allow the selection of artificial ageing parameters that correspond to a target level of erosion. The knowledge on artificial ageing and strength prediction acquired above is finally implemented on different types of glass to determine their strength after ageing and assess their safe use in cold bending / load bearing applications. The investigation showed that fully toughened glass has a superior performance to chemically toughened or annealed glass. Overall, the research presented in this thesis demonstrates that high quality cold bent toughened glass can be created when certain applied displacement limits are respected. These can be used as a safe, cost-effective and energy efficient replacement to the more conventional hot bent glass. However, cold bending / load bearing applications in which the stressed glass surface is exposed to ageing, require glass with a relatively high case depth such as fully toughened or bi-tempered glass.

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Al, Kindi Suad Said. "Artificial chemical ageing of atmospheric aerosol." Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/5550/.

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An aerosol chemical ageing (ACA) system has been developed for artificially processing atmospheric particles. An aerosol flow tube coupled to a scanning mobility particle sizer (SMPS) and an aerosol time-of-flight mass spectrometer (ATOFMS) have been proposed to study the heterogeneous reaction (HR) between two oxidants, ozone (O\(_3\)) and hydroxyl radical (OH), and three different single organic aerosol proxies: oleic acid (OL), maleic acid (MA) and bis(2-ethylhexyl) sebacate (BES). The ACA system operates under conditions equivalent to ambient processing times of 1 and 20 days with respect to ozone and OH ambient levels, respectively. The study provides evidence for the ageing process of organic aerosol. The physical characterisation of aged particles suggests the formation of volatile products resulting in appreciable decrease in particles size and mass. The chemical study, however, shows that the properties of the aged particles are sensitive to the oxidant and organic material identities, the particle size and the oxidation environment. The applicability of the developed ageing technique has been tested on real atmospheric particles, however, it is concluded that extrapolating laboratory procedures to ambient atmosphere may be challenging due to the complexity of the real atmosphere, particularly, the urban atmosphere.

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Desai, Krutarth. "California State University, San Bernardino Chatbot." CSUSB ScholarWorks, 2018. https://scholarworks.lib.csusb.edu/etd/775.

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Now-a-days the chatbot development has been moving from the field of Artificial-Intelligence labs to the desktops and mobile domain experts. In the fastest growing technology world, most smartphone users spend major time in the messaging apps such as Facebook messenger. A chatbot is a computer program that uses messaging channels to interact with users using natural Languages. Chatbot uses appropriate mapping techniques to transform user inputs into a relational database and fetch the data by calling an existing API and then sends an appropriate response to the user to drive its chats. Drawbacks include the need to learn and use chatbot specific languages such as AIML (Artificial Intelligence Markup Language), high botmaster interference, and the use of non-matured technology. In this project, Facebook messenger based chatbot is proposed to provide domain independent, an easy to use, smart, scalable, dynamic and conversational agent in order to get information about CSUSB. It has the unique functionalities which identify user interactions made by their natural language, and the flawless support of various application domains. This provides an ample of unique scalabilities and abilities that will be evaluated in the future phases of this project.

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Elvir, Miguel. "EPISODIC MEMORY MODEL FOR EMBODIED CONVERSATIONAL AGENTS." Master's thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3000.

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Embodied Conversational Agents (ECA) form part of a range of virtual characters whose intended purpose include engaging in natural conversations with human users. While works in literature are ripe with descriptions of attempts at producing viable ECA architectures, few authors have addressed the role of episodic memory models in conversational agents. This form of memory, which provides a sense of autobiographic record-keeping in humans, has only recently been peripherally integrated into dialog management tools for ECAs. In our work, we propose to take a closer look at the shared characteristics of episodic memory models in recent examples from the field. Additionally, we propose several enhancements to these existing models through a unified episodic memory model for ECAÂ s. As part of our research into episodic memory models, we present a process for determining the prevalent contexts in the conversations obtained from the aforementioned interactions. The process presented demonstrates the use of statistical and machine learning services, as well as Natural Language Processing techniques to extract relevant snippets from conversations. Finally, mechanisms to store, retrieve, and recall episodes from previous conversations are discussed. A primary contribution of this research is in the context of contemporary memory models for conversational agents and cognitive architectures. To the best of our knowledge, this is the first attempt at providing a comparative summary of existing works. As implementations of ECAs become more complex and encompass more realistic conversation engines, we expect that episodic memory models will continue to evolve and further enhance the naturalness of conversations.
M.S.Cp.E.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Computer Engineering MSCpE

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Azis, Norhafiz. "Ageing assessment of insulation paper with consideration of in-service ageing and natural ester application." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/ageing-assessment-of-insulation-paper-with-consideration-of-inservice-ageing-and-natural-ester-application(a4c668ed-31f3-41fe-9e8a-7ee51453ebe8).html.

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One of the cellulose insulation in high voltage power transformers is paper, and it is widely used in transformers due to low cost and excellent physical/electrical properties. However, the performance of paper could be affected by ageing. Ageing of paper is a complex phenomenon and can be influenced by many factors. This PhD thesis aimed to examine the ageing of paper in transformers based on Tensile Index (TI), dielectric strength and Low Molecular Weight Acid (LMA) measurements. The effect of ageing on the dielectric strength of paper was examined, through studying the influence of paper and oil ageing by-products such as LMA and HMA on the AC breakdown voltage. Meanwhile, the end of life for transmission transformer population in the UK was examined by studying the profile of LMA and TI of paper in scrapped transformers, with phase, winding, and layer locations taken into consideration. The relationship between TI, LMA and transformer age was modelled using previously published formulae in literature. The partitioning of LMA and HMA between mineral oil and paper was also investigated. Since TI is not directly measureable when a transformer is in-service, a TI prediction model was developed based on LMA measured in oil. The results indicated that there is no reduction effect of ageing (moderate towards severe) on the dielectric strength of paper, whereas the dielectric strength of paper is mainly influenced by the oil condition. LMA significantly reduces the breakdown voltage and accelerates the ageing of paper in mineral oil. The end of life based on TI is best represented by the 20 % retention of TI. Based on the case studies, the estimated end of life of transmission transformer population in the UK is around 43 years. The vertical distribution profile of LMA in paper and TI of paper along a winding is mainly influenced by vertical temperature profile. As paper ages, the amount of LMA in paper tends to increase as TI reduces. The percentage of LMA in service aged oil is about one fourth of Total Acid Number (TAN). The partition of LMA in mineral oil and paper favours its stay in paper and is heavily influenced by the weight ratio of paper and oil. The performance of the natural ester under high temperature ageing in open or sealed condition was evaluated based on TAN and viscosity measurements. The ratio of LMA and HMA in aged natural ester was examined. The effect of LMA and HMA on the AC breakdown voltage of natural ester and ageing of paper was also investigated. It was suggested that natural ester is suitable for application in hermetically sealed transformers. High temperature oxidation has significant effect on the physical and chemical properties of natural ester. Due to the polar nature of natural ester, the stay of LMA in natural ester is favoured over in paper which could be the reason why the breakdown voltage of natural ester and the ageing of paper are not significantly affected by LMA as in mineral oil.

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Brock, Walter A. "Alternative Approaches to Correction of Malapropisms in AIML Based Conversational Agents." NSUWorks, 2014. http://nsuworks.nova.edu/gscis_etd/20.

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The use of Conversational Agents (CAs) utilizing Artificial Intelligence Markup Language (AIML) has been studied in a number of disciplines. Previous research has shown a great deal of promise. It has also documented significant limitations in the abilities of these CAs. Many of these limitations are related specifically to the method employed by AIML to resolve ambiguities in the meaning and context of words. While methods exist to detect and correct common errors in spelling and grammar of sentences and queries submitted by a user, one class of input error that is particularly difficult to detect and correct is the malapropism. In this research a malapropism is defined a "verbal blunder in which one word is replaced by another similar in sound but different in meaning" ("malapropism," 2013). This research explored the use of alternative methods of correcting malapropisms in sentences input to AIML CAs using measures of Semantic Distance and tri-gram probabilities. Results of these alternate methods were compared against AIML CAs using only the Symbolic Reductions built into AIML. This research found that the use of the two methodologies studied here did indeed lead to a small, but measurable improvement in the performance of the CA in terms of the appropriateness of its responses as classified by human judges. However, it was also noted that in a large number of cases, the CA simply ignored the existence of a malapropism altogether in formulating its responses. In most of these cases, the interpretation and response to the user's input was of such a general nature that one might question the overall efficacy of the AIML engine. The answer to this question is a matter for further study.

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Bruno, Odemir Martinez. "Paralelismo em visão natural e artificial." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-26052014-161557/.

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Nesta tese são abordados, de maneira integrada, aspectos de paralelismo em visão natural e artificial, com discussões críticas das diversas áreas relacionadas. O paralelismo é discutido no sistema visual dos primatas, assim como suas principais contribuições e motivações incentivando a incorporação de paralelismo em sistemas de visão artificial. Um dos objetivos principais é fornecer as bases de paralelismo para o desenvolvimento do projeto Cyvis-1, uma proposta do Grupo de Pesquisa em Visão Cibernética (IFSC-USP) para visão versátil, com forte motivação biológica e baseada no córtex visual dos primatas. Para tanto, foi introduzida e implementada a proposta CVMP (Cybernetic Vision Message Passage), um conjunto de ferramentas para o desenvolvimento de aplicações paralelas em visão, tanto para sistemas distribuídos como para máquinas multiprocessadores. Baseada em programação orientada a objetos, interação homem-máquina, engenharia de software e programação visual, a proposta prima pelo desenvolvimento de forma simples e amigável. O CVMP é testado, avaliado e validado quanto a aspectos de funcionalidade e utilização, através da implementação paralela de diversos algoritmos de visão computacional e de processamento de imagens (operadores locais, transformada de Hough e transformada de Fourier, entre outros) os quais, além de ilustrar a utilização da ferramenta, são discutidos em termos de arquitetura e balanceamento de carga. São apresentadas três aplicações reais de sistemas paralelos de visão computacional, implementadas através do CVMP, demonstrando a eficiência da ferramenta, na implementação paralela, na utilização e cooperação de trabalho. Duas destas aplicações (integração de atributos visuais no projeto Cyvis-1 e um modelo de complexidade com base na percepção humana), foram desenvolvidas em conjunto com outros pesquisadores do Grupo de Pesquisa em Visão Cibernética. A terceira aplicação apresenta uma proposta do autor para um sistema automático de reconhecimento de plantas arbóreas (Botânica)
This thesis addresses, in an integrated way, the concept and usage of parallelism in natural and artificial vision. It starts by revising the primate visual system, and discussing how its principles and solutions can be extended to computational systems. One of the main objectives is to supply the parallelism backbone for the development of the Cyvis-1 System, which is a proposal of the Cybernetic Vision Research Group (IFSC-USP) for versatile vision, presenting a strong biological motivation, especially regarding the primate visual cortex. In order to achieve these objectives, the CVMP - Cybernetic Vision Message Passage - had to be developed, representing a set of simple and friendly parallel tools for computer vision applications in distributed and parallel (multiprocessor) systems, which is based on object oriented programming, human-machine interaction, software engineering and visual programming. The CVMP is tested, evaluated and validated with respect to functionality and utilization through the parallel implementation of several algorithms in computer vision and image processing (local operators, Hough transform, Fourier transform, etc.) which, in addition to illustrating the tools, are also discussed as far as their architecture and load balancing is concerned. Three applications of parallel computer vision systems to real situations are presented and implemented by using CVMP, corroborating the effectiveness of the tools in the parallel implementation, usage, and researcher integration. Two such applications (visual attributes integration in Cyvis-1 and a human complexity model) have been developed in collaboration with other researchers at the Cybernetic Vision Research Group. The third application presents the author\'s proposal for an automated system for arboreal plants recognition (Botany)

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Mirzakulova, Ekaterina Viktorovna. "Natural and Artificial Flavin-Based Catalysis." Bowling Green State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1371415783.

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Bhala, Maclean J. "Non-migratory antiozonant system for natural rubber." Thesis, Loughborough University, 1997. https://dspace.lboro.ac.uk/2134/12428.

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The current research on non-migratory antiozonant systems for natural rubber follows a tripartite study involving the formulation of a coating compound with static and dynamic ozone testing of the coatings, a review of some commercial in-mould coating techniques and analysis of diffusion of a commercial antiozonant through a coating. An outline of the mixing of Nipol 1312, a low molecular weight nitrile butadiene rubber grade produced by leon Chemicals Inc., with other ingredients to produce a coating composition is also given. Test pieces of the natural rubber substrate were placed in pre-coated mould cavities and cured under compression to achieve covulcanisation between the substrate and the coating. All ozone tests were carried out under standard ASTM DI149-911D518-91 conditions. Results show that the formulated nitrile rubber coating compound is able to protect natural rubber from ozone attack with no migration of the antiozonant as in classical chemical antiozonant systems. An up to date patent search on in-mould coating techniques and systems was carried out and evaluated in conjunction with some current commercial coating methods. In this overview, more emphasis is laid on the nature of the coating material which subsequently determines the appropriate coating technique, than on the specific in-mould coating process applied. Post-mould coating work with polyvinyl chloride (PVC) on natural rubber substrate was also assessed. An experimental and theoretical study of the diffusion of the antiozonant N,Isopropyl N-phenyl-pphenylenediamine (IPPD) through a protective coating on a natural rubber substrate is made in the project. This study shows that the protective coating is able to reduce the loss of antiozonant through diffusion while giving the rubber adequate protection from ozone. The study also demonstrates that the combination of a commercial antiozonant and a protective coating gives enhanced product service life and provides protection to damaged regions of the coating.

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Lindblom, Jessica. "Social Situatedness of Natural and Artificial Intelligence." Thesis, University of Skövde, Department of Computer Science, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-626.

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The situated approach in cognitive science and artificial intelligence (AI) has argued since the mid-1980s that intelligent behaviour emerges as a result of a close coupling between agent and environment. Lately, many researchers have emphasized that in addition to the physical environment, the social environment must not be neglected. In this thesis we will focus on the nature of social situatedness, and the aim of this dissertation is to investigate its role and relevance for natural and artificial intelligence.

This thesis brings together work from separate areas, presenting different perspectives on the role and mechanisms social situatedness. More specifically, we will analyse Vygotsky's cognitive development theory, studies of primate (and avian) intelligence, and last, but not least, work in contemporary socially situated AI. These, at a first glance, quite different fields have a lot in common since they particularly stress the importance of social embeddedness for the development of individual intelligence.

Combining these separate perspectives, we analyse the remaining differences between natural and artificial social situatedness. Our conclusion is that contemporary socially artificial intelligence research, although heavily inspired by empirical findings in human infants, tends to lack the developmental dimension of situatedness. Further we discuss some implications for research in cognitive science and AI.

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Young, Rupert. "Visual control in natural and artificial systems." Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/843083/.

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The desire to produce artificial vision systems which behave in an intelligent, humanlike way or which can autonomously and automatically perform tasks currently only performed by humans has been a goal of Artificial Intelligence research for many decades. Until recently much of the research concentrated on extracting visual representations of objects from single, static scenes. The last decade has seen an increase in interest concerning mobile robotics for navigation, planning and autonomous control as well as for the interpretation of events in real, dynamic scenes. Presented in this thesis is research on artificial vision systems from two different, but both necessary, standpoints. One concerns low-level vision-based behaviour of object tracking based upon a naturalistic theory of perception and behaviour within living systems. The other takes a more application and engineering based approach and its goal is to address high-level scene interpretation and control of processing resources. Numerous experiments are presented to demonstrate the various issues. The two main experiments, corresponding to the two research streams, are a system which is able to fixate complex multi-coloured objects and a fully integrated vision system for predicting and following, with a mobile sensor, events in a dynamic scene.

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Voznytsia, Anastasiia. "Operational objectives of natural and artificial systems." Thesis, National Aviation University, 2021. https://er.nau.edu.ua/handle/NAU/50990.

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1. Aziz, Abd El; Rasha Fady (2013). "Business Improvement using Organisational Goals, Riva Technique and e-Business Development Stages". Journal of Enterprise Information Management. 2. "Difference Between Strategic & Operational Objectives". Small Business. Retrieved November 2015. Check date values in: |access-date= (help) Hoang, Paul (2007). "Unit 1.3." Business & Management. IBID. pp. 40–51. 3. Harel, David. (2014). Algorithmics The Spirit of Computing. Springer Berlin. ISBN 978-3-642-44135-6. OCLC 876384882. 4. Schaeffer J. (2009) Didn't Samuel Solve That Game?. In: One Jump Ahead. Springer, Boston, MA
The work is devoted to the review and analysis of goals of natural and artificial systems functioning. The state of the system is usually referred to as several properties of the basic ones, which the system manages at a certain period of time. The fundamental property of systems is their stability, i.e. the ability of the system to withstand external influences. Life expectancy of the system depends on it.
Робота присвячена огляду та аналізу цілей функціонування природних та штучних систем. Стан системи зазвичай називають декількома властивостями основних, якими система управляє протягом певного періоду часу. Основною властивістю систем є їх стабільність, тобто здатність системи протистояти зовнішнім впливам. Від цього залежить тривалість життя системи.

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Gibson, Paul Martyn. "The application of hybrid neural network models to archaeofaunal ageing and interpretation." Thesis, University of York, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296383.

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Hattingh, Anna C. "The anti-ageing potential of rooibos: preserving preadipocyte funtion." Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/7804.

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Treatments with natural products rich in anti-oxidants have attracted remarkable interest in the cosmetic and pharmaceutical industry to combat oxidative stress and reverse the effects of ageing. Rooibos (Aspalathus linearis) is a South African fynbos plant, well-known for its strong anti-oxidant capacity and use in many cosmetic products. However, little published research exists on its potential as an anti-ageing treatment. The anti-ageing properties of fermented and green rooibos were investigated using an in vitro cell culture model designed to evaluate the involvement of mitochondrial dysfunction in the age related decline in preadipocyte function. Mitochondrial DNA (mtDNA) deficient preadipocytes, ρ0 3T3-L1preadipocytes, were generated following continuous long-term exposure to sub lethal concentrations of ethidium bromide (EtBr). Depletion of the mtDNA resulted in a significantly reduced mitochondrial membrane potential, rate of proliferation in culture, as well as an increased glucose utilization and lactate production. Treatment with the green rooibos (100 μg/mL) stimulated cell growth rates for both the wildtype and mutant cell lines. MtDNA depleted cells showed arrest in the G1 phase (48.8 ± 3.34%) compared to wildtype cells (44.6 ± 1.38%), which was significantly attenuated after treatment with green rooibos for mutant (42.0 ± 0.83%) and wildtype (36.5 ± 5.80%) treated cells. The results obtained for glucose utilization and lactate production, indicated a significant increase in glucose utilization along with a concomitant increase in lactate production after treatment with both green and fermented rooibos for wildtype and mutant cell lines. A significant improvement in mitochondrial membrane potential was also later observed after treatment with green and fermented rooibos on both the wildtype and mutant cell lines. The results obtained indicate that rooibos extracts, particularly the green rooibos, exhibit effects which preserve the functional capacity of preadipocytes exposed to ageing related insults, and indicate that rooibos could cause a metabolic shift in cells redirecting carbon flow away from mitochondrial metabolism, and towards lactate production and consequently, cells become resistant to mitochondrial dysfunction.

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Pires, André Rama. "A evidência do natural." Master's thesis, Universidade de Lisboa. Faculdade de Arquitetura, 2016. http://hdl.handle.net/10400.5/12661.

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Woolfson, Adrian. "Natural and artificial forms of human CD1 genes." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282946.

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Vasconcelos, Margarida Perloiro Morgadinho Pablo. "Densidade urbana entre o natural e o artificial." Master's thesis, Universidade de Lisboa, Faculdade de Arquitetura, 2017. http://hdl.handle.net/10400.5/14436.

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Koroidov, Sergey. "Water splitting in natural and artificial photosynthetic systems." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-86363.

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Photosynthesis is the unique biological process that converts carbon dioxide into organic compounds, for example sugars, using the energy of sunlight. Thereby solar energy is converted into chemical energy. Nearly all life depends on this reaction, either directly, or indirectly as the ultimate source of their food. Oxygenic photosynthesis occurs in plants, algae and cyanobacteria. This process created the present level of oxygen in the atmosphere, which allowed the formation of higher life, since respiration allows extracting up to 15-times more energy from organic matter than anaerobic fermentation. Oxygenic photosynthesis uses as substrate for the ubiquitous water. The light-induced oxidation of water to molecular oxygen (O2), catalyzed by the Mn4CaO5 cluster associated with the photosystem II (PS II) complex, is thus one of the most important and wide spread chemical processes occurring in the biosphere. Understanding the mechanism of water-oxidation by the Mn4CaO5 cluster is one of today’s great challenges in science. It is believed that one can extract basic principles of catalyst design from the natural system that than can be applied to artificial systems. Such systems can be used in the future for the generation of fuel from sunlight. In this thesis the light-induced production of molecular oxygen and carbon dioxide (CO2) by PSII was observed by membrane-inlet mass spectrometry. By analyzing this observation is shown that CO2 not only is the substrate in photosynthesis for the production of sugars, but that it also regulates the efficiency of the initial steps of the electron transport chain of oxygenic photosynthesis by acting, in form of HCO3-, as acceptor for protons produced during water-splitting. This finding concludes the 50-years old search for the function of CO2/HCO3− in photosynthetic water oxidation. For understanding the mechanism of water oxidation it is crucial to resolve the structures of all oxidation states, including transient once, of the Mn4CaO5 cluster. With this application in mind a new illumination setup was developed and characterized that allowed to bring the Mn4CaO5 cluster of PSII microcrystals into known oxidation states while they flow through a narrow capillary. The optimized illumination conditions were employed at the X-ray free electron laser at the Linac Coherent Light Source (LCLS) to obtain simultaneous x-ray diffraction (XRD) and x-ray emission spectroscopy (XES) at room temperature. This two methods probe the overall protein structure and the electronic structure of the Mn4CaO5 cluster, respectively. Data are presented from both the dark state (S1) and the first illuminated state (S2) of PS II. This approach opens new directions for studying structural changes during the catalytic cycle of the Mn4CaO5 cluster, and for resolving the mechanism of O-O bond formation. In two other projects the mechanism of molecular oxygen formation by artificial water oxidation catalysts containing inexpensive and abundant elements were studied. Oxygen evolution catalyzed by calcium manganese and manganese only oxides was studied in 18O-enriched water. It was concluded that molecular oxygen is formed by entirely different pathways depending on what chemical oxidant was used. Only strong non-oxygen donating oxidants were found to support ‘true’ water-oxidation. For cobalt oxides a study was designed to understand the mechanistic details of how the O-O bond forms. The data demonstrate that O-O bond formation occurs by direct coupling between two terminal water-derived ligands. Moreover, by detailed theoretical modelling of the data the number of cobalt atoms per catalytic site was derived.

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Rashid, Azura. "Investigation of the effect of ageing on the strength properties of natural rubber." Thesis, Queen Mary, University of London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406045.

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Tachtatzis, Phaedra Maria. "Accelerated ageing, senescence and the natural history of chronic hepatitis B virus infection." Thesis, University of Aberdeen, 2015. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=228557.

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Hepatitis B virus infection (HBV) is an important health problem worldwide, with a significant rate of chronic infection, which can lead to cirrhosis and hepatocellular carcinoma (HCC). Increased age is an important determinant of progression to cirrhosis and HCC, possibly because age is a crude measure of the duration of HBV infection. Increasing age is associated with changes in liver structure, blood flow and function and with reduced response to injury, impaired regeneration and increased mortality in acute liver disease. Age has been identified as a co‐factor in several chronic liver diseases including chronic hepatitis C infection (HCV). Available evidence suggests differential ageing of various intrahepatic cell types in different liver diseases and the ageing process may be more complex in the liver than originally thought. Telomeres are DNA structures located at the end of each chromosome, which protect the underlying coding DNA from breaks and fusions and shorten with increasing age. Both DNA damage and cell proliferation lead to progressive telomere shortening, which ultimately leads to cell cycle arrest and a state of replicative senescence. Persistent HCV and HBV infections lead to cell cycle arrest, providing a favourable environment for viral replication. Evidence suggests that progressive telomere shortening occurs with advancing stage of liver disease in HBV and specifically from cirrhosis through large cell dysplasia to small cell dysplasia and to HCC. Whether cell cycle arrest leads to a senescent‐like state or whether this is the result of oxidative stress is unknown. Unpublished data using cell cycle phase markers in chronic HBV infection reveal that hepatocytes, which support HBV replication, are arrested in G1, which is mediated by hepatocyte p21 expression. I hypothesise that: 1. In normal liver tissue, different cell types age at different rates and this is altered during disease; 2. Hepatocyte senescence plays a significant role in the natural course of chronic HBV infection and underlies HBV antigen expression. I developed and optimised large volume Q‐FISH methodology to measure telomere length and nuclear size in a variety of intrahepatic cell lineages. In normal liver tissue, cholangiocytes had longer telomeres compared with all other intrahepatic lineages over a wide age range. Hepatocytes did not show any age‐related telomere shortening, in contrast to Kupffer and hepatic stellate cells. In chronic HBV infection, all hepatocytes had shortened telomeres when compared to age and sex‐matched controls consistent with accelerated ageing. HBV replication was confined to those hepatocytes with longer telomeres, suggesting that HBV entry or replication is less efficient in older hepatocytes and compatible with the fall in serum HBV DNA and HBsAg titre seen with advancing age. There may be two populations of hepatocytes in chronic HBV infection; hepatocytes that are growth arrested with short telomeres not supporting HBV replication and biologically 'younger' hepatocytes with longer telomeres that do support HBV replication. The change in cellular HBV antigen localisation with disease progression is also explained by age related changes in HBV expression. Nuclear Hepatitis B core antigen expression (HBcAg), characteristic of the early immune tolerant phase of infection, was associated with the longest telomeres, while cytoplasmic HBcAg expression was associated with shorter telomeres. Furthermore, the total number of hepatocyte telomeres fell with increasing fibrosis stage. Hepatocyte nuclear size, a marker of senescence, increased as HBcAg expression shifted from nucleus to cytoplasm; and p21, another senescence marker, never co‐localised with HBcAg expression. These results suggest that the location and production of HBV antigens are related to increased functional hepatocyte age and the onset of cellular senescence.

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Thei, Judith. "Artificial ageing of Japanese lacquerware and comparison of conservation treatments for photodegraded Japanese lacquer surfaces." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/9462.

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The aim of the work was to devise a methodology to artificially age urushi (Japanese lacquer) samples and to test a series of different treatments, both Western and Japanese, to conserve urushi objects for future generations. The results of this work need to consider the wider implication of cross-cultural objects to obtain the most effective and sympathetic conservation treatment. By comparing the Mazarin chest (an urushi object at the V&A museum) and two other disparate, yet related, cross-cultural conservation and restoration projects, it is demonstrated how the cultural background of an object can affect its value and the consequent effects this can have during conservation. Microcracks form on the surface of urushi as it ages, similar to those seen from desiccation cracking. These microcracks are initiated by the formation of pinholes and light degradation. The pinholes form because of changes in relative humidity. Temperature also plays a role in the formation of pinholes, but oxidation occurs at high temperatures. Different light sources will produce different degradation of urushi surfaces. The effect of solvents used for cleaning and diluting urushi were tested. Polar solvents such as acetone damage the surface of urushi. Solvents that would be suitable for conservation include Solvesso A and Han 8070. Two conservation materials were used to treat aged urushi surfaces: a Western resin (Paraloid B72) and urushi. Both gatame (used dilute to fill the cracks) and suri (used to cover the surface) style treatments were used. The B72 was too dilute to draw any conclusions on its effectiveness. Using urushi, the suri treatment was more effective than gatame. The effect of a coating of shellac, as was often used to ‘restore’ urushi objects in the West, was also investigated. The shellac showed some cracking after ageing, and was very difficult to remove even with aggressive solvents.

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Li, Shanghao. "Theoretical Insight into Mechanisms of Natural and Artificial Metalloproteases." Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_theses/265.

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In this study, theoretical and computational approaches have been utilized to investigate the mechanisms of natural and artificial metalloproteases. The active sites of most natural metalloproteases contain a tetrahedral zinc center, coordinated by three amino acid residues combinated from His(N), Cys(S), Glu(O), and Asp(O) with a water molecule as the fourth ligand. However, the roles played by the ligands environment in the catalytic functions of enzyme are not clear. In this study, the effects of different ligand combinations (NS2, N2S, N2O, N3, S3, NO2 and NSO) in the mechanism were investigated energy barriers were compared. The machanism and energetics of the substrate bound artificial metalloproteases Ni(II)cyclen (cyclen: 1,4,7,10-tetraazacyclododecane) and Cd(II)cyclen have been investigated. In addition, the mechanism of hydrolysis of Phe-Phe peptide bond catalyzed by another artificial metalloprotease [Pd(H2O)4]2+ has also been studied.

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Arican, Zafer. "Vision-based Robot Localization Using Artificial And Natural Landmarks." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605333/index.pdf.

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In mobile robot applications, it is an important issue for a robot to know where it is. Accurate localization becomes crucial for navigation and map building applications because both route to follow and positions of the objects to be inserted into the map highly depend on the position of the robot in the environment. For localization, the robot uses the measurements that it takes by various devices such as laser rangefinders, sonars, odometry devices and vision. Generally these devices give the distances of the objects in the environment to the robot and proceesing these distance information, the robot finds its location in the environment. In this thesis, two vision-based robot localization algorithms are implemented. The first algorithm uses artificial landmarks as the objects around the robot and by measuring the positions of these landmarks with respect to the camera system, the robot locates itself in the environment. Locations of these landmarks are known. The second algorithm instead of using artificial landmarks, estimates its location by measuring the positions of the objects that naturally exist in the environment. These objects are treated as natural landmarks and locations of these landmarks are not known initially. A three-wheeled robot base on which a stereo camera system is mounted is used as the mobile robot unit. Processing and control tasks of the system is performed by a stationary PC. Experiments are performed on this robot system. The stereo camera system is the measurement device for this robot.

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Cameron, Craig G. "Natural and artificial fluorescence on 3-dimensional bioorganic nanostructures." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53451.

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A challenge exists for understanding the origin of color for structurally colored, 3-dimensional bioorganic nanostructures, such as the scales of butterflies, beetles, and moths. Complex, hierarchical structures found within such scales create the overall scale appearance. The controlled alteration of color through material deposition and the addition of new optical functionalities to such structures are other areas of scientific interest. This dissertation addresses these challenges with a first-of-its-kind, systematic isolation (deconstruction) of scale component nanostructures, followed by evaluation of optical property/structure correlations. The additive deposition (constructive alteration) of emissive materials to structurally-colored templates complements this deconstructive approach towards understanding the origin of color in butterfly scales. Discoveries made through this work may help advance the bioinspired design of synthetic optical structures and subsequent color control through the addition of multilayered, emissive optical components.

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Ramey, Holly Rene. "Mapping natural and artificial selection events in animal genomes." Thesis, University of Missouri - Columbia, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10182613.

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Oliveira, Inês Mouco de. "Entre o natural e o artificial, uma topografia urbana." Master's thesis, Universidade de Lisboa. Faculdade de Arquitetura, 2016. http://hdl.handle.net/10400.5/13556.

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Sichula, Vincent A. "Flavins and Their Analogues as Natural and Artificial Catalysts." Bowling Green State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1294288149.

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32

Smith, Terrance J. "Foot and Ankle Injuries: Artificial Turf vs. Natural grass." Wittenberg University Honors Theses / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wuhonors1470240556.

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Rosolem, Rafael. "Land Surface Processes In Natural and Artificial Tropical Ecosystems." Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/194510.

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Land Surface Parameterization (LSP) schemes have evolved from simple tipping-bucket models to fully interactive models, including parameterizations which account for exchanges of momentum, energy, mass, and biogeochemistry. As the demand for greater realism has increased, so has the complexity of LSPs which now includes some parameters that may not be universally relevant to all regions of the globe. The performance of LSP schemes depends on the magnitude of structural, data-related (input and output), and parameter uncertainties in the model. Parameter estimation uncertainty can be reduced by calibrating LSPs against measurements available at field sites. Given the multiple outputs of the models, multi-objective optimization approaches are performed. Some of the parameter values used in LSPs have originally obtained from laboratory studies which analyzed plant behavior under a range of conditions in enclosed chambers. The research described in this dissertation takes advantage of currently available data from several eddy covariance flux towers located mainly in the Brazilian Amazon basin to estimate parameter values of a widely-used LSP scheme, version 3 of the Simple Biosphere model (SiB3). Background climatological data was used to assess the representativeness of the data collection period that might have affected model calibration. Variance-based sensitivity analysis was then used to investigate potential structural deficiencies in SiB3 and to reduce the dimensionality of the subsequent optimization by identifying those model parameters that merit calibration. Finally, some structural and conceptual aspects of SiB3 were tested inside Biosphere 2 Tropical Rain Forest biome (B2-TRF) under meteorological conditions that resemble those predicted in future climate scenarios for the Amazon basin.

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Säberg, Mikael. "Sustainability of Artificial Turf Fields : Comparative life cycle assessment of artificial and natural turf fields." Thesis, Linköpings universitet, Industriell miljöteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177901.

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Soccer accounts for a third of the Swedish sports movement with 3 503 fields of both natural and artificial turf. The European Union will make a decision in 2021 on how to handle the issue of rubber performance infill. This infill can be found in artificial turf fields and are used for performance properties. The problem with this infill is the microplastics that spreads into the nature which is considered as toxic. Because of this the EU have decided to either ban or provide mandatory rules to reduce the spread of rubber performance infill. The north and the majority of Sweden’s climate is not adapted for play of soccer on natural turf according to FIFA, and EU want to ban or provide mandatory rules for artificial turfs. This action from the EU can perturb the entire Swedish sports movement since soccer accounts for a third of that movement. This study was therefore created to show if artificial turf fields are as bad for the environment as rumours has said compared with the natural turfs. To investigate this, a life cycle assessment (LCA) was performed regarding the global warming potential (GWP) and embodied water consumption for three different field types: an artificial turf field with recycled SBR, an artificial turf field with cork and a natural turf field. The result visualised that a natural turf field had the highest embodied water consumption and the highest impact on the GWP of a ten-year life cycle while the artificial turf field with recycled SBR had the least embodied water consumption and the least impact on the GWP. The findings of this LCA were that Sweden for the moment is dependent on artificial turf and the rubber performance infill, since the material properties are the best adapted to their climate. Therefore, a ban would be a risk for the Swedish sports movement. It was also revealed that natural turf fields in Sweden consumes at least 50 % municipal drinking water when irrigate. The high GWP impact came from the production of fertilisers (NPK). This report has shown how artificial turf and natural turf can work together in an industrial symbiosis by making the artificial turf field constructed to collect rainwater and use that water to irrigate the natural turf with.

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Agnew, Hannah Clare. "The effects of healthy ageing on biological motion perception, attention and natural scene categorisation." Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=236938.

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Healthy ageing in the absence of neurodegenerative diseases is accompanied by a variety of perceptual and cognitive changes, which can occur on various distinct but interacting levels. Much research has been devoted to understanding how basic cognitive functions such as working memory and attention change with age. However, only more recently has age-related changes on perceptual functions been investigated, thus less is understood. My thesis aimed to address this gap in the literature, by exploring age-related changes in visual perception, specifically changes related to visual temporal processing of natural and biological stimuli. Also investigated was the extent to which age-related changes in perceptual and cognitive functions affect each other. Chapter 2 investigated the time course of visual processing of natural scene categorisation in older adults. Younger, young-old and old-old adults performed a go/no-go task, in which they had to respond to images of animals whilst ignoring images of landscapes. The results showed that the temporal processing of complex scenes is impaired in healthy older adults and this deficit becomes more pronounced with increasing age. Chapter 3 assessed whether age-related decline in biological motion perception is mediated by impaired attentional abilities. Younger and older adults performed a series of tasks assessing biological motion perception and visual attention. The results indicated that age-related changes in biological motion perception are not driven by general attentional decline. Lastly, Chapter 4 explored whether age-related changes in biological motion and attention tasks can be explained by differences in the allocation of attention. Younger and older adults performed a conjunctive visual search, and two biological motion tasks, while their eye movements were being tracked. The results illustrated that differences in the allocation of attention cannot explain age-related differences found on biological motion perception and attention tasks. Overall, my findings provide substantial evidence to suggest that both visual perceptual and cognitive abilities change with healthy ageing. However, my results also indicate that certain aspects of these two functions remain relatively preserved in older adulthood.

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Ealey, Douglas. "Natural language acquisition in large scale neural semantic networks." Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310843.

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Zhu, Shuxiang. "Big Data System to Support Natural Disaster Analysis." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1592404690195316.

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Whalen, Joann. "Evaluation of soil Arylsulfatase enzymes using natural and artificial substrates." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22826.

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The response of soil arylsulfatase enzymes to natural and artificial substrates was evaluated. An immobilized arylsulfatase reactor was used to hydrolyse ester sulfate compounds in two soils with different morphological properties and management schemes. Hydrolysable ester sulfates cleaved by the immobilized arylsulfatase reactor constituted 35 to 55% of the HI-reducible S in these soils. Naturally occurring low molecular weight (LMW) ester sulfate compounds were found to accumulate in soil and persist during storage. These compounds were examined as the naturally occurring substrate for soil arylsulfatase enzymes.
Arylsulfatase activity was evaluated using artificial (p-nitrophenol sulfate) and natural (LMW ester sulfates) substrates. The response of arylsulfatase activity in soil and humic-arylsulfatase complexes to p-nitrophenol sulfate did not reflect the ability of these complexes to hydrolyse natural soil substrates.
A preliminary experiment was conducted to examine arylsulfatase activity and soil sulfur in relation to sulfur in plant tissue and grain from wheat. Tissue sulfur was more strongly associated with soil sulfur than wheat grain.

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Bentley, Katie Anne. "Adaptive behaviour through morphological plasticity in natural and artificial systems." Thesis, University College London (University of London), 2006. http://discovery.ucl.ac.uk/1444539/.

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Our concept of intelligence is changing. Embodiment has led to the rise of morphologies in Artificial Intelligence (AI) research. This thesis focuses on two research questions: 1) How can system morphologies, well-adapted to changing environments, be designed? 2) How can adaptive behaviour be generated through morphology? It is the fundamental argument of this thesis that morphological plasticity (MP), the environmentally induced variation in growth or development, can provide a solution to both questions. Specifically, this thesis is based around a detailed study of diatom valve morphogenesis. Diatoms, a unicellular organism, construct intricate siliceous structures (valves) around themselves which exhibit high plasticity to the environment. Diatom valve morphogenesis is a good example of how morphologies can be well-adapted to changing environments, an open problem in AI, and how adaptive behaviour can be generated through morphological processes alone. Through a constructivist approach this thesis contributes to both understanding of MP in natural systems and the design of MP algorithms for artificial adaptive systems. Several original models and frameworks are defined within this thesis: the Nature's Batik Model of basic diatom valve morphogenesis the Cellanimat, a 'Dynamic Morphology' based on the unicell, capable of MP driven adaptive behaviour through its unique 'Artificial Cytoskeleton' model of cytoskeletal dynamics the Environment-Phenotype Map framework and the Cellanimat Colony Model, which combines all previous models for the investigation of MP mechanisms during diatom colony formation. Cellanimat dynamics and optimization are thoroughly investigated and the model is shown to be multi functional, evolvable, scalable and reasonably robust.

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Wulff, Brande Bruce Hertel. "Natural and artificial evolution of tomato Cf-9 resistance homologues." Thesis, University of East Anglia, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249755.

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Demirtaş, Fatma Aslıhan 1970. "Artificial nature : water infrastructure and its experience as natural space." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/65716.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2000.
Includes bibliographical references (p. 159-163).
This work is about water infrastructure and its experience as urban and natural space. It deals with the concepts of nature/geography, technology, and the integral experiential space by analyzing water dams and reservoirs that are more than utilitarian structures. In the process of formulating the concept of ARTIFICIAL NATURE, an expanded definition of 'built activity' to embrace landscape/nature, infrastructure, and technology as well as imaginative and mental space is pursued. The specific sites of investigation range from Thrace to Central and Southeastern Anatolia in Turkey from 1920-2000.
by Fatma Aslıhan Demirtaş.
S.M.

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Li, Dan M. Arch Massachusetts Institute of Technology. "Fluid atmospheres : adaptive interplay between natural and artificial light projection." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/103472.

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Thesis: M. Arch., Massachusetts Institute of Technology, Department of Architecture, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 94-95).
Imagine. This is the same daily route you travel and the same space you pass through. And it is not. How do we create an adaptive and customized space with no materials at all? Can the generic be customized and specific at the same time? Given extra layers of "light" a compose-able architecture is yet to come. A building is a living, breathing space that is ever moving and rapidly morphing - its animus is time. Take a closer look at the surfaces that enclose our space: there are screens with news, lectures, movie clips; there are windows, shadows and shade created by lights of all different kinds; there are colors and ornamentations that inform us of the history of our architectural lineage. Sunlight naturally creates an evolving atmosphere with the change in time and the seasons; now, with new technologies, we can create even more dynamic atmospheres with light that engage and collaborate with the sun. Light exists in two forms: natural light and artificial light created from technology. Sunlight creates our everyday perception of the physical world, and thus, our ability to understand and live in the space around us. Nevertheless, "digital light" is becoming a larger and larger part of our lives, as we perceive and create information through the medium of a screen. However, "digital light" does not always need to be flat -- through projection mapping, we can create a three-dimensional light that leaves the 2D surface of the screen and is responsive to the environment of the physical world. Using this method, our perception of the physical space will not only change due to the passing of the sun, but also from our own agency in creating altered environments through designed projection systems. This project creates a methodology and a toolkit to design dynamic spaces with natural and projection lighting that allows for customization and alterations of space. Through this system, the static building itself becomes the instrument that is played. This project also demonstrates these tools through investigating projections with light in the atrium of MIT Brain and Cognitive Sciences Complex building.
by Dan Li.
M. Arch.

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Raj, Towfique. "Molecular signatures of natural and artificial selection in mammalian genomes." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609021.

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Faísca, Pedro Miguel Portela. "Comparison of organic matter decomposition between natural and artificial ponds." Master's thesis, Universidade de Évora, 2019. http://hdl.handle.net/10174/24405.

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Litter decomposition is a key ecosystem service within aquatic ecosystems and is a complex process that is sensitive to environmental factors. The role of microbial and macrofaunal decomposers, and how it changes across environmental gradients is not yet fully understood. Decomposition was assessed across 6 biogeographical regions to determine the role of macroinvertebrates in this ecosystem service. Decomposition was estimated using standardized cotton strips, which were deployed in the mesocosms of each region. The role of macroinvertebrates was tested with an exclusion experiment which allowed or prevented the access of macroinvertebrates to cotton strips, a similar experiment was also conducted in natural ponds. After 64 days the cotton strips were collected, and mass loss and tensile strength were measured. There were significant differences in the rate of decomposition across different regions and no differences were found between systems. Macroinvertebrates played an important role, with gatherers being major players; Resumo: A decomposição é um serviço de ecossistema chave e um processo complexo sensível a factores ambientais. O papel de decompositores microbianos e da macrofauna, e como este papel muda num gradiente ambiental não é completamente entendido. A decomposição foi avaliada em 6 zonas biogeográficas para determinar o papel de macroinvertebrados neste serviço de ecossistema. A decomposição foi estimada utilizando tiras de algodão, colocadas em mesocosmos nas diferentes regiões. O papel dos macroinvertebrados foi testado através de uma experiência de exclusão que permitia ou impedia o acesso de macroinvertebrados às tiras, uma experiência semelhante foi realizada em charcos naturais. Ao fim de 64 dias, as tiras de algodão foram recolhidas e a perda de massa e tensão foram quantificadas. Encontraram-se diferenças significativas na decomposição entre as diferentes regiões, mas não se observaram diferenças entre sistemas. Os macroinvertebrados têm um papel importante neste serviço de ecossistema, sendo as espécies colectoras as mais importantes

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Li, Junyan. "Computational biomechanics/biotribological modelling of natural and artificial hip joints." Thesis, University of Leeds, 2013. http://etheses.whiterose.ac.uk/5500/.

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The excellent hip function and potential degeneration are closely linked with the unique structure of the joint cartilage that is principally composed of a solid phase and a fluid phase. Once damaged, the joint may need to be replaced by prosthesis in order to restore function in hip kinematics and kinetics. However, to what extent this can be achieved has yet to be quantified. On the other hand, the role of fluid pressurisation which plays in hip function has been poorly understood. The aim of this thesis was to address these issues. To evaluate the gait abnormality, particularly in terms of hip contact forces, a musculoskeletal model of lower extremity was constructed in a rigid-body dynamics frame, and the hip kinematics and kinetics were determined and cross-compared for a group of asymptomatic total hip replacement (THR) patients, THR patients with symptoms of symptomatic leg length inequality (LLI) and normal healthy people. Significant abnormal patterns in gait kinetics were observed for the asymptomatic THR patients, and this abnormality was greater for the LLI patients. To understand contact mechanics and the associated fluid pressurisation within the hip cartilage, a three dimensional finite element (FE) hip model with biphasic cartilage layers were developed. The protocol was compared to other solvers. A set of sensitivity studies were undertaken to evaluate the influence of model parameters, and then the model was evaluated under a range of loads with different activities. In all the cases, the fluid supported over 90% of the load for a prolonged period, potentially providing excellent hip function and lubrication. The musculoskeletal model and FE joint were combined to investigate the performance of the non-operated joint of the THR / LLI patients during gait which was found to function in a mechanically abnormal but not adverse environment. Lastly, the methodology of the biphasic hip modelling was validated using an experimental porcine hip of hemiarthroplasty. Good agreement was achieved between the FE predictions and the experimental measurement of the contact area.

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46

Leal, Ana Maria. "Conditioning of Manila clam broodstock on natural and artificial diets." Thesis, Bangor University, 1994. https://research.bangor.ac.uk/portal/en/theses/conditioning-of-manila-clam-broodstock-on-natural-and-artificial-diets(0ec43f18-fa32-4d46-9dab-e8e7ea2979ee).html.

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Two trials in 1991 and another two in 1992 were carried out on the broodstock conditioning of Manila clams, Tapes philippinarum. The main objective was to manipulate the lipid and polyunsaturated fatty acid content of Manila clam eggs by maintaining broodstock in different dietary regimes. The second objective was to assess dried algae as alternative diets for conditioning broodstock. Clams were brought into the laboratory from the natural environment early in the year, before gametogenesis had started. Supplements of cultured live (Dunaliella tertiolecta, Skeletonema costatum, Tetraselmis suecica and Isochrysis galbana) and dried algae (T. suecica) diets were fed to the broodstock, usually in a range of mixed diets, at rations equivalent to 3% or 6% of the initial dry meat weight of the broodstock in dry weight of algae per day. The microalgae differed in their long-chain polyunsaturated fatty acid content (PUFA). Unfed control clams received only the organic material which remained in the sea water after sand filtration. The nutritional value of these diets in relation to gametogenesis, fecundity, quality of eggs, and viability and growth of larvae were assessed. Dry T. suecica was the same food value as live T. suecica but Manila clams produced more eggs if supplements of live algae were added. The requirement for conditioning Manila clams (32 mm shell length) to spawn with live or dry T. suecica+S. costatum was 500 to 700 "day-degrees" (D°). With dry T. suecica on its own or mixed with I. galbana, S. costatum and D. tertiolecta it was 500 to 600 Do (44 mm shell length). In one trial clams spawned in the tanks (equivalent to 462 Do) before the first attempt to spawn them was made. Successful spawning was dependent on the quantity and quality of the algal diet during gametogenesis. With a 6% food ration, clams fed dry T. suecica+S. costatum or dry T. suecica+l. galbana produced the highest number of eggs (an average of 3.2 and 4.5 million eggs per female, respectively). The average fecundity was 83% lower when the diet was reduced to a 3% food ration. The dry meat weight, condition index and fecundity of fed broodstock were significantly higher than for unfed animals. The quantity of lipid in the eggs, usually between 4 and 9 ng egg-1, was similar whatever the broodstock diet. However, levels of the essential polyunsaturated fatty acids 20: 5w3 and 22: 6w3 in the eggs were low if the broodstock diet was deficient in these PUFAs. Even though diet manipulation caused changes in the fatty acid composition of the eggs, growth and survival of Manila clam larvae was not reduced in a hatchery situation.

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Dittmar, George William. "Object Detection and Recognition in Natural Settings." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/926.

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Much research as of late has focused on biologically inspired vision models that are based on our understanding of how the visual cortex processes information. One prominent example of such a system is HMAX [17]. HMAX attempts to simulate the biological process for object recognition in cortex based on the model proposed by Hubel & Wiesel [10]. This thesis investigates the ability of an HMAX-like system (GLIMPSE [20]) to perform object-detection in cluttered natural scenes. I evaluate these results using the StreetScenes database from MIT [1, 8]. This thesis addresses three questions: (1) Can the GLIMPSE-based object detection system replicate the results on object-detection reported by Bileschi using HMAX? (2) Which features computed by GLIMPSE lead to the best object-detection performance? (3) What effect does elimination of clutter in the training sets have on the performance of our system? As part of this thesis, I built an object detection and recognition system using GLIMPSE [20] and demonstrate that it approximately replicates the results reported in Bileschi's thesis. In addition, I found that extracting and combining features from GLIMPSE using different layers of the HMAX model gives the best overall invariance to position, scale and translation for recognition tasks, but comes with a much higher computational overhead. Further contributions include the creation of modified training and test sets based on the StreetScenes database, with removed clutter in the training data and extending the annotations for the detection task to cover more objects of interest that were not in the original annotations of the database.

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Lacerda, Jose Neves de. "Generalização de fatos na compreensão de textos em linguagem natural." reponame:Repositório Institucional da UFSC, 1996. https://repositorio.ufsc.br/xmlui/handle/123456789/158062.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnologico
Made available in DSpace on 2016-01-08T21:01:46Z (GMT). No. of bitstreams: 1 104809.pdf: 2836599 bytes, checksum: 361e8157da674b3f2eeef6595b3db383 (MD5) Previous issue date: 1996
As comunicações humanas são, de forma geral, incompletas em relação ao seu conteúdo. Muito conhecimento é transmitido em poucas palavras. Isso é possível porque existe, em nossa memória, um conhecimento pré-existente sobre o mundo, suas coisas, e interrelações existentes entre estas coisas, que nós utilizamos para complementar as lacunas existentes nas comunicações recebidas. Sistemas quc compreendam a linguagem humana, estudados em Inteligência Artificial, precisam ser capazes de fazer esse tipo de atividade, para nós tão natural. O uso adequado desse recurso dá ao sistema uma capacidade de interpretação maior do que a oferecida pela pura análise sintático-semântica das sentenças. O objetivo dessa dissertação é descrever um processo automático de criação dessas estruturas de dados, de forma a poderem, posteriormente, ser utilizadas na interpretação de textos em linguagem natural. Tratadas aqui como ?fatos genéricos?, seu papel é o de representar aquilo que conhecemos como senso comum. Essa dissertação descreve um sistema que ?compreende? textos escritos em linguagem natural e, a partir dos fatos identificados nessa compreensão, constrói estruturas semânticas, manipuláveis, que representam genericamente estes fatos. Apresentamos a base teórica, as definições das estruturas semânticas e das bases de dados utilizadas, os algoritmos de análise, interpretação e generalização de fatos, e demonstramos o funcionameato do sistema implementado. Problemas relacionados às alternativas adotadas são discutidos.

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Fracasso, Federico. "INFLUENCE OF QUENCH RATE ON THE HARDNESS OBTAINED AFTER ARTIFICIAL AGEING OF AN Al-Si-Mg ALLOY." Thesis, Jönköping University, JTH. Research area Materials and Manufacturing - Casting, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-12558.

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50

Sadeghian, Keyarash. "Quantum chemical investigations on sensory photoreceptors in natural and artificial systems." kostenfrei, 2008. http://www.opus-bayern.de/uni-regensburg/volltexte/2009/1140/.

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Dissertations / Theses on the topic 'Natural and artificial ageing'

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