533 research outputs found

    Techniques for data pattern selection and abstraction

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    This thesis concerns the problem of prototype reduction in instance-based learning. In order to deal with problems such as storage requirements, sensitivity to noise and computational complexity, various algorithms have been presented that condense the number of stored prototypes, while maintaining competent classification accuracy. Instance selection, which recovers a smaller subset of the original training set, is the most widely used technique for instance reduction. But, prototype abstraction that generates new prototypes to replace the initial ones has also gained a lot of interest recently. The major contribution of this work is the proposal of four novel frameworks for performing prototype reduction, the Class Boundary Preserving algorithm (CBP), a hybrid method that uses both selection and generation of prototypes, Instance Seriation for Prototype Abstraction (ISPA), which is an abstraction algorithm, and two selective techniques, Spectral Instance Reduction (SIR) and Direct Weight Optimization (DWO). CBP is a multi-stage method based on a simple heuristic that is very effective in identifying samples close to class borders. Using a noise filter harmful instances are removed, while the powerful heuristic determines the geometrical distribution of patterns around every instance. Together with the concepts of nearest enemy pairs and mean shift clustering this algorithm decides on the final set of retained prototypes. DWO is a selection model whose output set of prototypes is decided by a set of binary weights. These weights are computed according to an objective function composed of the ratio between the nearest friend and nearest enemy of every sample. In order to obtain good quality results DWO is optimized using a genetic algorithm. ISPA is an abstraction technique that employs the concept of data seriation to organize instances in an arrangement that favours merging between them. As a result, a new set of prototypes is created. Results show that CBP, SIR and DWO, the three major algorithms presented in this thesis, are competent and efficient in terms of at least one of the two basic objectives, classification accuracy and condensation ratio. The comparison against other successful condensation algorithms illustrates the competitiveness of the proposed models. The SIR algorithm presents a set of border discriminating features (BDFs) that depicts the local distribution of friends and enemies of all samples. These are then used along with spectral graph theory to partition the training set in to border and internal instances

    CItyMaker

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    Due to its complexity, the evolution of cities is something that is difficult to predict and planning new developments for cities is therefore a difficult task. This complexity can be identified on two levels: on a micro level, it emerges from the multiple relations between the many components and actors in cities, whereas on a macro level it stems from the geographical, social and economic relations between cities. However, many of these relations can be measured. The design of plans for cities can only be improved if designers are able to address measurements of some of the relationships between the components of cities during the design process. These measurements are called urban indicators. By calculating such measurements, designers can grasp the meaning of the changes being proposed, not just as simple alternative layouts, but also in terms of the changes in indicators adding a qualitative perception. This thesis presents a method and a set of tools to generate alternative solutions for an urban context. The method proposes the use of a combined set of design patterns encoding typical design moves used by urban designers. The combination of patterns generates different layouts which can be adjusted by manipulating several parameters in relation to updated urban indicators. The patterns were developed from observation of typical urban design procedures, first encoded as discursive grammars and later translated into parametric design patterns. The CItyMaker method and tools allows the designer to compose a design solution from a set of programmatic premises and fine-tune it by pulling parameters whilst checking the changes in urban indicators. These tools improve the designer’s awareness of the consequences of their design moves

    CItyMaker:

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    Due to its complexity, the evolution of cities is something that is difficult to predict and planning new developments for cities is therefore a difficult task. This complexity can be identified on two levels: on a micro level, it emerges from the multiple relations between the many components and actors in cities, whereas on a macro level it stems from the geographical, social and economic relations between cities. However, many of these relations can be measured. The design of plans for cities can only be improved if designers are able to address measurements of some of the relationships between the components of cities during the design process. These measurements are called urban indicators. By calculating such measurements, designers can grasp the meaning of the changes being proposed, not just as simple alternative layouts, but also in terms of the changes in indicators adding a qualitative perception. This thesis presents a method and a set of tools to generate alternative solutions for an urban context. The method proposes the use of a combined set of design patterns encoding typical design moves used by urban designers. The combination of patterns generates different layouts which can be adjusted by manipulating several parameters in relation to updated urban indicators. The patterns were developed from observation of typical urban design procedures, first encoded as discursive grammars and later translated into parametric design patterns. The CItyMaker method and tools allows the designer to compose a design solution from a set of programmatic premises and fine-tune it by pulling parameters whilst checking the changes in urban indicators. These tools improve the designer’s awareness of the consequences of their design moves

    SAGA: A project to automate the management of software production systems

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    The Software Automation, Generation and Administration (SAGA) project is investigating the design and construction of practical software engineering environments for developing and maintaining aerospace systems and applications software. The research includes the practical organization of the software lifecycle, configuration management, software requirements specifications, executable specifications, design methodologies, programming, verification, validation and testing, version control, maintenance, the reuse of software, software libraries, documentation, and automated management

    Context-Based classification of objects in topographic data

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    Large-scale topographic databases model real world features as vector data objects. These can be point, line or area features. Each of these map objects is assigned to a descriptive class; for example, an area feature might be classed as a building, a garden or a road. Topographic data is subject to continual updates from cartographic surveys and ongoing quality improvement. One of the most important aspects of this is assignment and verification of class descriptions to each area feature. These attributes can be added manually, but, due to the vast volume of data involved, automated techniques are desirable to classify these polygons. Analogy is a key thought process that underpins learning and has been the subject of much research in the field of artificial intelligence (AI). An analogy identifies structural similarity between a well-known source domain and a less familiar target domain. In many cases, information present in the source can then be mapped to the target, yielding a better understanding of the latter. The solution of geometric analogy problems has been a fruitful area of AI research. We observe that there is a correlation between objects in geometric analogy problem domains and map features in topographic data. We describe two topographic area feature classification tools that use descriptions of neighbouring features to identify analogies between polygons: content vector matching (CVM) and context structure matching (CSM). CVM and CSM classify an area feature by matching its neighbourhood context against those of analogous polygons whose class is known. Both classifiers were implemented and then tested on high quality topographic polygon data supplied by Ordnance Survey (Great Britain). Area features were found to exhibit a high degree of variation in their neighbourhoods. CVM correctly classified 85.38% of the 79.03% of features it attempted to classify. The accuracy for CSM was 85.96% of the 62.96% of features it tried to identify. Thus, CVM can classify 25.53% more features than CSM, but is slightly less accurate. Both techniques excelled at identifying the feature classes that predominate in suburban data. Our structure-based classification approach may also benefit other types of spatial data, such as topographic line data, small-scale topographic data, raster data, architectural plans and circuit diagrams

    Applications of Molecular Dynamics simulations for biomolecular systems and improvements to density-based clustering in the analysis

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    Molecular Dynamics simulations provide a powerful tool to study biomolecular systems with atomistic detail. The key to better understand the function and behaviour of these molecules can often be found in their structural variability. Simulations can help to expose this information that is otherwise experimentally hard or impossible to attain. This work covers two application examples for which a sampling and a characterisation of the conformational ensemble could reveal the structural basis to answer a topical research question. For the fungal toxin phalloidin—a small bicyclic peptide—observed product ratios in different cyclisation reactions could be rationalised by assessing the conformational pre-organisation of precursor fragments. For the C-type lectin receptor langerin, conformational changes induced by different side-chain protonations could deliver an explanation of the pH-dependency in the protein’s calcium-binding. The investigations were accompanied by the continued development of a density-based clustering protocol into a respective software package, which is generally well applicable for the use case of extracting conformational states from Molecular Dynamics data

    Evaluating four and five-year old children's responses to interactive television programs

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    While it is commonly believed that 'interactive' media provides benefits to young children not obtained from 'non-interactive' media, there has been little research examining this issue, or the kinds of interactivity that elicit these benefits. The present study examined the attention, comprehension, and enjoyment of young children viewing different kinds of interactive television programs compared with those of children viewing the control prototype (non-interactive) programs. Three interactive prototypes and one control prototype of Dora the Explorer, Hi-5, and Play School were examined on these outcome measures. The interactive prototypes allowed participants to make simple choices about program content using a television remote control. Four hundred and ninety eight children aged four (49.4%) and five (50.6%) years individually viewed one of the prototypes, and the children's attention, comprehension, and enjoyment were examined. Participants were boys (49.7%) and girls (50.3%) drawn from Government (64.9%), Catholic (27.6%) and Independent (7.4%) schools in Perth, Western Australia. Significantly higher attention, comprehension, or both were found for children interacting with two of the prototypes allowing increased viewer participation compared to children viewing the control prototype prototypes. Interactive prototypes allowing participants to repeat sections of program content also elicited significantly higher comprehension than control prototypes. However, interactive prototypes allowing participants to customise aspects of the program did not result in differences in the outcome measures compared with control prototypes. It was also found that interactive prototypes offering participants narrative choices were associated with significantly lower attention, comprehension or enjoyment for either interacting or non-interacting participants compared to the control prototypes. It is argued that interactivity, per se, does not bestow any benefits, with only specific models of interactivity resulting in higher comprehension or attention. In fact, some applications allowing young children to make choices about program narrative appears to disrupt program comprehension. It is concluded that successful interactivity builds upon the features of well-designed traditional children's television; opportunities for increased participation, and the repetition of content

    Proceedings of the GIS Research UK 18th Annual Conference GISRUK 2010

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    This volume holds the papers from the 18th annual GIS Research UK (GISRUK). This year the conference, hosted at University College London (UCL), from Wednesday 14 to Friday 16 April 2010. The conference covered the areas of core geographic information science research as well as applications domains such as crime and health and technological developments in LBS and the geoweb. UCL’s research mission as a global university is based around a series of Grand Challenges that affect us all, and these were accommodated in GISRUK 2010. The overarching theme this year was “Global Challenges”, with specific focus on the following themes: * Crime and Place * Environmental Change * Intelligent Transport * Public Health and Epidemiology * Simulation and Modelling * London as a global city * The geoweb and neo-geography * Open GIS and Volunteered Geographic Information * Human-Computer Interaction and GIS Traditionally, GISRUK has provided a platform for early career researchers as well as those with a significant track record of achievement in the area. As such, the conference provides a welcome blend of innovative thinking and mature reflection. GISRUK is the premier academic GIS conference in the UK and we are keen to maintain its outstanding record of achievement in developing GIS in the UK and beyond

    Gaming Platform vs. Traditional Text-only Stated-Preference Survey of Neighborhood Choice

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    This research explores the influence of representational methods as they are used in stated-preference (SP) surveys of neighbourhood choice. These types of surveys have traditionally been administered in text-only format, by asking subjects which alternative they prefer based on written descriptions of neighbourhoods. It has been argued, alternately, that the visual presentation of attributes can either dominate in SP surveys, or that it can be used to help improve the realism of choice tasks, and/or increase the number of attributes that can be included in such surveys. A few studies have tested the difference between multimedia and text-only SP surveys of housing choice. While these studies have been informative, they have drawn conflicting conclusions, and have been based on small sample sizes. The research presented here sought to take advantage of the capabilities made available by gaming engines to compare the results of SP surveys of neighbourhood choice administered either on a gaming platform, or as a traditional text-only survey. A sample of 368 (184 for each survey) respondents was used to compare neighbourhood choice model parameter estimates drawn from data administered with the two different survey methodologies. We found that while both surveys result in similar models, the model estimated using data obtained from the gaming platform show slightly better performance; providing 3D simulations appears to better focus respondent attention. At the same time, these 3D simulations have the unfortunate drawback of decreasing the generalizability of some visual parameter estimates, as they need to provide precise visual representations of their characteristics

    Dissemination, Future Research and Education:

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    This booklet is one of three final documentations of the results of the COST-Action TU 1403 ‘ADAPTIVE FACADE NETWORK’ to be published next to the proceedings of the Final COST Conference ‘FACADE 2018 – ADAPTIVE!’ and a Special Issue of the Journal of Façade Design & Engineering (JFDE). While the proceedings and the journal present current scientific research papers selected through a traditional peer review process, these three final documentations have another focus and objective. These three documentations will share a more holistic and comparative view to the scientific and educational framework of this COST-Action on adaptive facades with the objective to generate an overview and a summary – different from the more specific approach of the proceedings and connecting to the first publication that was presenting the participating institutions. The three titles are the following and are connected to the deliverables of the responsible Working Groups (WG): Booklet 3.1 Case Studies (WG1) Booklet 3.2 Building Performance Simulation and Characterisation of Adaptive Facades (WG2) Booklet 3.3 Dissemination, Future Research and Education (WG4) Booklet 3.1 concentrates on the definition and classification of adaptive facades by describing the state of the art of real-world and research projects and by providing a database to be published on COST TU 1403 website (http://tu1403.eu/). Booklet 3.2 focusses on comparing simulation and testing methods, tools and facilities. And finally, Booklet 3.3 documents the interdisciplinary, horizontal and vertical networking and communication between the different stakeholders of the COST-Action organised through Short Term Scientific Missions (STSM), Training Schools and support sessions for Early Stage Researchers (ESR) / Early Career Investigators (ECI), industry workshops, and related surveys as specific means of dissemination to connect research and education. All three booklets show the diversity of approaches to the topic of adaptive facades coming from the different participants and stakeholders, such as: architecture and design, engineering and simulation, operation and management, industry and fabrication and from education and research. The tasks and deliverables of Working Group 4 were organized and supported by the following group members and their functions: – Thomas Henriksen, Denmark ESR/ECI – Ulrich Knaack, The Netherlands Chair (2015-16) – Thaleia Konstantinou, The Netherlands ESR/ECI – Christian Louter, The Netherlands Vice-Chair, STSM Coordinator – Andreas Luible, Switzerland Website, Meetings – David Metcalfe, United Kingdom Training Schools – Uta Pottgiesser, Germany Chair (2017-18) As editors and Chairs, we would like to thank the Working Group members and authors from other Working Groups for their significant and comprehensive contributions to this booklet. Moreover, we sincerely thank Ashal Tyurkay for her great assistance during the whole editing and layout process. We also want to thank COST (European Cooperation in Science and Technology)
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