4 research outputs found

    Requirements for Topology in 3D GIS

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    Topology and its various benefits are well understood within the context of 2D Geographical Information Systems. However, requirements in three-dimensional (3D) applications have yet to be defined, with factors such as lack of users' familiarity with the potential of such systems impeding this process. In this paper, we identify and review a number of requirements for topology in 3D applications. The review utilises existing topological frameworks and data models as a starting point. Three key areas were studied for the purposes of requirements identification, namely existing 2D topological systems, requirements for visualisation in 3D and requirements for 3D analysis supported by topology. This was followed by analysis of application areas such as earth sciences and urban modelling which are traditionally associated with GIS, as well as others including medical, biological and chemical science. Requirements for topological functionality in 3D were then grouped and categorised. The paper concludes by suggesting that these requirements can be used as a basis for the implementation of topology in 3D. It is the aim of this review to serve as a focus for further discussion and identification of additional applications that would benefit from 3D topology. © 2006 The Authors. Journal compilation © 2006 Blackwell Publishing Ltd

    REVERSE ENGINEERING OF THE HUMAN FIBULA BY USING METHOD OF ANATOMICAL FEATURES

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    This paper describes reverse engineering (RE) of human fibula, on right male bone, using the method of anatomical features (MAF) with the aim to obtain 3D surface model. The first step in the process of reverse engineering was CT scanning and digitalization of data. CT data were obtained with Toshiba MSCT scanner Aquillion 64 and saved in DICOM format. This data were subjected to further processing and imported in Computer Aided Design (CAD) program as STL file. The process continues in CAD program with identification and determination of Referential Geometrical Entities (RGEs) which are crucial for RE process. These RGEs are the basis for definition of axis and planes of intersection. Intersecting polygonal model of fibula bone on upper and lower extremities and the body with these planes gives as result set of curves, which were used for points determination on them. Through these points splines were pulled, and with loft function surface models of extremities and the body of fibula bone is built. Joining and merging of these models leaded to 3D shape model of fibula bone. Accuracy of the model is confirmed by conducting distance and deviation analysis. Model is suitable for rapid prototyping, reconstruction missing parts of fibula bone, orthopedic training and simulation

    3D modeling of the human upper limb including the biomechanics of joints, muscles and soft tissues

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    The challenge in virtual human modeling is to achieve the representation of the main human characteristics with as much realism as possible. Such achievements would allow the simulation and/or analysis of many virtual situations involving humans. Simulation is especially useful to derive information from the models so as to predict and/or reproduce the behaviors that would be observed in real situations. Computer methods in visualization and simulation have thus great potential for advances in medicine. The processes of strength generation and motion coordination are some of these phenomena for which there is still much remaining to be understood. The human shoulder is also probably the articulation of the human body which deserves more than any other to be named "terra incognita". Investigations towards the biomechanical modeling and simulation of the human upper limb are therefore presented in this study. It includes thorough investigation into the musculoskeletal anatomy and biomechanics of the human upper limb, into the biomechanical constitutive modeling of muscles and soft tissues, and into the nonlinear continuum mechanics and numerical methods, especially the incremental finite element methods, necessary for their simulation. On this basis, a 3-D biomechanical musculoskeletal human upper limb model has been designed using the Visible Human Data provided by the U.S. National Library of Medicine, and applied to the dynamic musculoskeletal simulation of the human upper limb. This research has been achieved in the context of the EU ESPRIT Project CHARM, whose objective has been to develop a comprehensive human animation resource database and a set of software tools allowing the modeling of the human complex musculoskeletal system and the simulation of its dynamics, including the finite element simulation of soft tissue deformation and muscular contraction. An investigation towards the application of this knowledge for the realistic modeling and animation of the upper limb in computer animation is then presented. The anatomical and biomechanical modeling of the scapulo-thoracic constraint and the shoulder joint sinus cones are proposed and applied to the realistic animation, using inverse kinematics, of a virtual skeleton and an anatomic musculoskeletal body model
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