10 research outputs found

    Multisensory analytics for several interconnected scalar fields analysis

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    In our day it's hard to imagine modern research in sophisticated scientific area without use of visual analytics tools. However, humans are able to receive and analyze information about world around them not only through their eyes, but with help of other sensory stimuli as well and there is no reason why scientific data analyses should be an exception. As a result, there is a lot of research done recently in area of multimodal interfaces that are characterized by various sensory stimuli involvement and especially in visual-auditory interfaces development. In this work we introduce multisensory analytics approach, discuss theoretical issues, introduce main concepts of software tools implementing our approach, describe one of the possible auditory-visual mappings methods for particular case of scalar fields analyses - simultaneous interconnected scalar fields analyses and give practical examples

    Survey and modelling for the bim of Basilica of San Marco in Venice

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    The Basilica of San Marco is a singular case in the field of Cultural heritage, as it constitutes a construction site always active for the maintenance and preservation of the basilica itself. The continuous intervention of conservation, due to the particular environmental conditions of Venice and the opening to the public, together with the complexity of the building itself, imposes the need to identify an optimized management system. For this reason, in 2013 the Procurator of St. Marco Basilica commissioned the construction of a 3D model of the Basilica to be used for the creation of a BIM. The model must meet the required precision of the scale of 1: 50, and should also include, in addition to the geometric description, a description of the mosaic and marble surfaces of the basilica through high resolution orthophoto which are essential for the restoration of the mosaics. The complexity of the church and the large and continuous flow of public led to work in non-optimal conditions especially for the acquisition stage. The basilica has certain peculiarities that led to some important choices, for example the use of photogrammetry instead of laser scanning technique. The same technique was preferred also by the need to realize, in addition to the geometric model, high-resolution orthophotos of marbles and mosaic surfaces. The modelling of the basilica has highlighted a number of problems related to the building features. The basilica, indeed, is the result of the juxtaposition of elements (capitals, columns) with different origin, which therefore cannot be standardized in special libraries. Moreover, especially in the extensive mosaic areas, there are not edges that characterize the architecture, but only beveled surfaces. This has resulted in a change also in the modeling paradigm with the need to identify alternative systems even for the construction of simple elements. Therefore, we decided to model using NURBS since it is the method that allows greater adherence to reality and, at the same time, a model with acceptable dimensions in terms of navigation and usability. Only the most sculptural pieces such as capitals and statues have been replaced by mesh models. As we were interested in different elaborations, the results of this work are a geometric NURBS model for the subsequent insertion into BIM environment, with the possibility of extracting two-dimensional drawings such as plans and sections, a mesh model with low resolution textures for online navigation and high resolution orthophotos. The survey work and modeling has been almost completed for the interior of the basilica whereas only the external remains to be acquired and modeled. For the management of the entire work it was decided to use the data organization system already used by the Politecnico di Milano for the Duomo di Milano. The BIM3DSURVEY system will be essential not only to manage the finished model, but it has been very useful also during the construction phase because it allows us to divide the entire work into more work units. However, this system required some changes to meet the peculiarity of this BIM, in particular the need to append and link the orthophotos to real surfaces, in order to use the model also as a spatial index for the images

    3D reconstruction using a spherical spiral scan camera

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    Thesis (Master)--Izmir Institute of Technology, Computer Engineering, Izmir, 2006Includes bibliographical references (leaves: 48-49)Text in English; Abstract: Turkish and Englishviii, 50 leavesConstruction of 3D models representing industrial products/objects is commonly used as a preliminary step of production process. These models are represented by a set of points which can be combined by planar patches (i.e. triangulation) or by smooth surface approximtions. In some cases, we may need to construct the 3D models of real objects. This problem is known as the 3D reconstruction problem which is one of the most important problems in the field of computer vision. In this thesis, a sytem has been developed to transform images of real objects into their 3D models automatically. The system consists of a PC, an inexpensive camera and an electromechanical component. The camera attached to this component moves around the object over a spiral trajectory and observes it from different view angles. At the same time, feature points of object surface are tracked using a tracking algorithm over object images. Then tracked points are reconstructed in 3D space using a stereo vision technique. A surface approximation is fitted to this 3D point set as a last step in the process. Open source .Intel®-OpenCV. C library is used both in image capturing and in image processing

    Identifying and Investigating Intrusive Scanning Patterns by Visualizing Network Telescope Traffic in a 3-D Scatter-plot

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    Detecting and investigating intrusive Internet activity is an ever-present challenge for network administrators and security researchers. Network monitoring can generate large, unmanageable amounts of log data, which further complicates distinguishing between illegitimate and legiti-mate traffic. Considering the above issue, this article has two aims. First, it describes an investigative methodology for network monitoring and traffic review; and second, it discusses results from applying this meth-od. The method entails a combination of network telescope traffic cap-ture and visualisation. Observing traffic from the perspective of a dedi-cated sensor network reduces the volume of data and alleviates the concern of confusing malicious traffic with legitimate traffic. Compliment-ing this, visual analysis facilitates the rapid review and correlation of events, thereby utilizing human intelligence in the identification of scan-ning patterns. To demonstrate the proposed method, several months of network telescope traffic is captured and analysed with a tailor made 3D scatter-plot visualisation. As the results show, the visualisation saliently conveys anomalous patterns, and further analysis reveals that these patterns are indicative of covert network probing activity. By incorporat-ing visual analysis with traditional approaches, such as textual log re-view and the use of an intrusion detection system, this research contrib-utes improved insight into network scanning incidents

    SURVEY AND MODELLING FOR THE BIM OF BASILICA OF SAN MARCO IN VENICE

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    Design of a six degrees of freedom haptic device

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    From the open-loop tele-operator systems of 1950’s to the modern kinesthetic training and surgery support setups, haptic systems took a long way of evolution. Application areas ranging from minimally invasive surgery to space training systems for astronauts, still there is a large room for improvements. The vast areas of emerging applications put a number of demands on haptic interfaces. Fidelity, large workspace and high force/torque capacity are among those demands. The thesis concentrates on the design of a haptic master arm. The mechanical system with an analysis of dynamics properties, electronic hardware, algorithms for forward and inverse kinematics and software for the integration of sensors and actuators are developed to create an infrastructure for haptic interaction. Though the major design criteria applied in this design are a large workspace and high force/torque capacity, dynamics compensation techniques are also discussed as part of the developed infrastructure. The main focus of the thesis is the design of this hardware and software base for haptic applications rather than the design of haptic control algorithms. A survey on haptic interfaces and master arm design criteria is presented firstly. A set of specifications for the master arm is determined for a general and multipurpose yet ergonomic use. Newton-Euler based simulation techniques are employed for the component selection. Sensors and controller hardware are selected according to the demands of the haptic control problem. Dynamics compensation techniques for the designed manipulator are considered and tested in simulation. Finally the designed master arm is assembled and electrically integrated

    Data preparation for biomedical knowledge domain visualization: a probabilistic record linkage and information fusion approach to citation data

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    This thesis presents a methodology of data preparation with probabilistic record linkage and information fusion for improving and enriching information visualizations of biomedical citation data. The problem of record linkage of citation databases where only non-unique identifiers such as author names and document titles are available as common identifiers to be linked was investigated. This problem in citation data parallels problems in clinical data and Knowledge Discovery in Databases (KDD) methods from clinical data mining are evaluated. Probabilistic and deterministic (exact-match) record linkage models were developed and compared through the use of a gold standard or truth dataset. Empirical comparison with ROC analysis of record linkage models showed a significant difference (p=.000) in performance of a probabilistic model over deterministic models. The methodology was evaluated with probabilistic linkage of records from the Web of Science, Medline, and CINAHL citation databases in the knowledge domains of medical informatics, HIV/AIDS, and nursing informatics. Data quality metrics for datasets prepared with probabilistic record linkage and information fusion showed improvement in completeness of key variables and reduction in sample bias. The resulting visualizations offered a richer information space for users through an increase in terms entering the visualization. The significant contributions of this work include the development of a novel model of probabilistic record linkage for biomedical citation databases which improves upon existing deterministic models. In addition a methodology for improving and enriching knowledge domain visualizations though a data preparation approach has been validated with analyses of multiple citation databases and knowledge domains. The data preparation methodology of probabilistic record linkage with information fusion offers a remedy for data quality problems, and the opportunity to enrich visualizations with added content for user exploration, which in turn improves the utility of knowledge domain visualizations as a medium for assessing available evidence and forming hypotheses.Ph.D., Information Science -- Drexel University, 200

    Tecnologias de streaming em contextos de aprendizagem

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    Mestrado Sistemas de InformaçãoAs instituições de ensino, nomeadamente no ensino superior, atravessam uma fase de adaptação à cultura tecnológica dos alunos, que, nos últimos anos, tem vindo a sofrer alterações num ritmo elevado, introduzindo novas necessidades, o que justifica uma observação atenta e pode sugerir alterações às metodologias no sentido da sua melhor adequação aos novos paradigmas de aprendizagem. A crescente utilização de tecnologias de streaming e o potencial impacto que parecem introduzir na flexibilidade do processo de aprendizagem, pode contribuir para a inovação nos conteúdos e, onsequentemente, nas actividades propostas, cuja necessidade de mudança deriva dos novos contextos tecnológicos em que os alunos estão inseridos. Este trabalho propõe a utilização e validação de elementos multimédia sincronizados, distribuídos em streaming, como suporte a actividades em novos contextos de aprendizagem, quer para apoio a momentos de aprendizagem não presencial, quer em actividades presenciais. A metodologia proposta tem como objectivo a criação e distribuição de conteúdos eficazes, de forma segura, num processo de aprendizagem distribuído e com públicoalvo heterogéneo, adequados às novas necessidades dos alunos e sem motivar choques culturais. A aplicação desta metodologia nos casos realizados, permitiu registar um enorme entusiasmo dos alunos e a manifestação do seu interesse em intensificar a utilização do formato proposto, alargando-o a outras disciplinas.The education institutions, particularly in higher education, are in an adaptation phase to the technological culture of the students, which in the last years has rapidly changed, introducing new requirements. This cultural change recommends a close observation of this phenomenon and can suggest some methodology adaptations to best fit the new learning paradigms. The increasing use of streaming technologies and the potential impact they seem to have in the learning process’s flexibility, can contribute to the innovation of pedagogical activities and learning contents, whose need for change is demanded by the student’s new technological context. This work propose the use and validation of synchronized media elements, delivered using streaming technologies, as a support to classroom and elearning activities in the new learning contexts. The methodology proposed within this project intends to guide the development and safe delivery of effective learning contents, in a distributed learning environment, to heterogeneous classes with new requirements, avoiding cultural conflicts. The use of this methodology in the accomplished experiences, showed a huge enthusiasm and adhesion of the students, which are looking forward for the methodology to be widen to other courses

    Progressive haptic guidance for a dynamic task in a virtual training environment

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    This thesis presents the motivation for and implementation of a novel progressive haptic guidance scheme designed to improve the efficiency of a virtual training environment used for skill acquisition. A detailed expertise-based analysis of the dynamic human motor task identifies the key skills required for success and motivates the progressive haptic guidance scheme. The thesis compares the effectiveness of the scheme to similar visual guidance, written guidance and no-guidance. The experimental training protocol presents a target-hitting training task in a virtual environment that utilizes an LCD display for visual feedback and a force feedback joystick for haptic interactions. This protocol lasts eleven sessions over a two-month period, thereby ensuring the performance saturation of participants. During each session, the number of target hits obtained becomes the objective measure of performance. Two additional measures, trajectory error and input frequency, are defined and implemented to calculate the performance of participants in two key skills. The guidance scheme then employs these last two measures as gain inputs to the guidance controller, which in turn progressively diminishes the forces that display guidance as virtual walls. The haptic controller design initially restricts a participant's motion to a preferred task path, but increased performance results in decreased guidance from one trial to the next. In addition to these measures, the protocol also presents the computerized version of the NASA Task Load Index (TLX) to all participants at each session, thereby providing cognitive workload measurements throughout the entire training period. The results demonstrate that this progressive haptic guidance scheme, one that integrates key skills and measures of performance, significantly outperforms three other guidance modes early on in the training and only when guidance is active. The data failed to show whether the haptic guidance scheme has significantly higher performance when the guidance is inactive. This scheme also generates less frustration and mental workload than visual guidance. Possible applications for these findings include virtual training environments designed for surgery and rehabilitation

    Knowledge in the making: Prototyping and human-centred design practice.

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    This thesis presents an enquiry into the nature and role of prototyping within human-centred design practice, examining the capabilities and limitations of emerging prototyping technologies within this context. A contextual review explores the significance of the human element in design. This leads to the proposal of a paradigm statement for human-centred design which informs the theoretical and practical research activity undertaken in the course of this investigation. A critical review of literature aimed at the design and engineering professions identifies a rhetoric celebrating the virtualisation of design processes. Here, advocates of emerging virtual prototyping technologies argue computer-based simulation techniques may reduce or replace physical prototype iterations, thereby greatly increasing the speed and efficiency of new product development processes. This thesis questions the extent to which virtual prototyping can replace physical human input in design. A counter argument to the designer's total immersion in the virtual design world is that valuable creative opportunities may be revealed through discovery-oriented physical prototyping. Furthermore, it may not be possible to adequately describe all aspects of a design proposal using virtual methods alone. This is demonstrated in practical investigations in which designers sought to exploit tactile qualities as essential features in design, and also in cases involving complex structural behaviour. Despite significant advances in virtual prototyping technologies, there remain some types of design problem which may only be identified and addressed through the making and testing of physical models. Moreover, this thesis argues that the valuable practical knowledge which may be derived through hands-on engagement and manipulation of physical prototypes and materials must be retained as an essential human element in design
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