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Sample records for 3-d geometric models

  1. Geometric and Colour Data Fusion for Outdoor 3D Models

    PubMed Central

    Merchán, Pilar; Adán, Antonio; Salamanca, Santiago; Domínguez, Vicente; Chacón, Ricardo

    2012-01-01

    This paper deals with the generation of accurate, dense and coloured 3D models of outdoor scenarios from scanners. This is a challenging research field in which several problems still remain unsolved. In particular, the process of 3D model creation in outdoor scenes may be inefficient if the scene is digitalized under unsuitable technical (specific scanner on-board camera) and environmental (rain, dampness, changing illumination) conditions. We address our research towards the integration of images and range data to produce photorealistic models. Our proposal is based on decoupling the colour integration and geometry reconstruction stages, making them independent and controlled processes. This issue is approached from two different viewpoints. On the one hand, given a complete model (geometry plus texture), we propose a method to modify the original texture provided by the scanner on-board camera with the colour information extracted from external images taken at given moments and under specific environmental conditions. On the other hand, we propose an algorithm to directly assign external images onto the complete geometric model, thus avoiding tedious on-line calibration processes. We present the work conducted on two large Roman archaeological sites dating from the first century A.D., namely, the Theatre of Segobriga and the Fori Porticus of Emerita Augusta, both in Spain. The results obtained demonstrate that our approach could be useful in the digitalization and 3D modelling fields. PMID:22969327

  2. Geometric and colour data fusion for outdoor 3D models.

    PubMed

    Merchán, Pilar; Adán, Antonio; Salamanca, Santiago; Domínguez, Vicente; Chacón, Ricardo

    2012-01-01

    This paper deals with the generation of accurate, dense and coloured 3D models of outdoor scenarios from scanners. This is a challenging research field in which several problems still remain unsolved. In particular, the process of 3D model creation in outdoor scenes may be inefficient if the scene is digitalized under unsuitable technical (specific scanner on-board camera) and environmental (rain, dampness, changing illumination) conditions. We address our research towards the integration of images and range data to produce photorealistic models. Our proposal is based on decoupling the colour integration and geometry reconstruction stages, making them independent and controlled processes. This issue is approached from two different viewpoints. On the one hand, given a complete model (geometry plus texture), we propose a method to modify the original texture provided by the scanner on-board camera with the colour information extracted from external images taken at given moments and under specific environmental conditions. On the other hand, we propose an algorithm to directly assign external images onto the complete geometric model, thus avoiding tedious on-line calibration processes. We present the work conducted on two large Roman archaeological sites dating from the first century A.D., namely, the Theatre of Segobriga and the Fori Porticus of Emerita Augusta, both in Spain. The results obtained demonstrate that our approach could be useful in the digitalization and 3D modelling fields.

  3. Geometric and Textural Blending for 3D Model Stylization.

    PubMed

    Huang, YiJheng; Lin, Wen-Chieh; Yeh, I-Cheng; Lee, Tong-Yee

    2017-01-25

    Stylizing a 3D model with characteristic shapes or appearances is common in product design, particularly in the design of 3D model merchandise, such as souvenirs, toys, furniture, and stylized items. A model stylization approach is proposed in this study. The approach combines base and style models while preserving user-specified shape features of the base model and the attractive features of the style model with limited assistance from a user. The two models are first combined at the topological level. A tree-growing technique is utilized to search for all possible combinations of the two models. Second, the models are combined at textural and geometric levels by employing a morphing technique. Results show that the proposed approach generates various appealing models and allows users to control the diversity of the output models and adjust the blending degree between the base and style models. The results of this work are also experimentally compared with those of a recent work through a user study. The comparison indicates that our results are more appealing, feature-preserving, and reasonable than those of the compared previous study. The proposed system allows product designers to easily explore design possibilities and assists novice users in creating their own stylized models.

  4. Methods for Geometric Data Validation of 3d City Models

    NASA Astrophysics Data System (ADS)

    Wagner, D.; Alam, N.; Wewetzer, M.; Pries, M.; Coors, V.

    2015-12-01

    Geometric quality of 3D city models is crucial for data analysis and simulation tasks, which are part of modern applications of the data (e.g. potential heating energy consumption of city quarters, solar potential, etc.). Geometric quality in these contexts is however a different concept as it is for 2D maps. In the latter case, aspects such as positional or temporal accuracy and correctness represent typical quality metrics of the data. They are defined in ISO 19157 and should be mentioned as part of the metadata. 3D data has a far wider range of aspects which influence their quality, plus the idea of quality itself is application dependent. Thus, concepts for definition of quality are needed, including methods to validate these definitions. Quality on this sense means internal validation and detection of inconsistent or wrong geometry according to a predefined set of rules. A useful starting point would be to have correct geometry in accordance with ISO 19107. A valid solid should consist of planar faces which touch their neighbours exclusively in defined corner points and edges. No gaps between them are allowed, and the whole feature must be 2-manifold. In this paper, we present methods to validate common geometric requirements for building geometry. Different checks based on several algorithms have been implemented to validate a set of rules derived from the solid definition mentioned above (e.g. water tightness of the solid or planarity of its polygons), as they were developed for the software tool CityDoctor. The method of each check is specified, with a special focus on the discussion of tolerance values where they are necessary. The checks include polygon level checks to validate the correctness of each polygon, i.e. closeness of the bounding linear ring and planarity. On the solid level, which is only validated if the polygons have passed validation, correct polygon orientation is checked, after self-intersections outside of defined corner points and edges

  5. 3-D Geometric Modeling for the 21st Century.

    ERIC Educational Resources Information Center

    Ault, Holly K.

    1999-01-01

    Describes new geometric computer models used in contemporary computer-aided design (CAD) software including wire frame, surface, solid, and parametric models. Reviews their use in engineering design and discusses the impact of these new technologies on the engineering design graphics curriculum. (Author/CCM)

  6. Using 3D Geometric Models to Teach Spatial Geometry Concepts.

    ERIC Educational Resources Information Center

    Bertoline, Gary R.

    1991-01-01

    An explanation of 3-D Computer Aided Design (CAD) usage to teach spatial geometry concepts using nontraditional techniques is presented. The software packages CADKEY and AutoCAD are described as well as their usefulness in solving space geometry problems. (KR)

  7. Improving Semantic Updating Method on 3d City Models Using Hybrid Semantic-Geometric 3d Segmentation Technique

    NASA Astrophysics Data System (ADS)

    Sharkawi, K.-H.; Abdul-Rahman, A.

    2013-09-01

    to LoD4. The accuracy and structural complexity of the 3D objects increases with the LoD level where LoD0 is the simplest LoD (2.5D; Digital Terrain Model (DTM) + building or roof print) while LoD4 is the most complex LoD (architectural details with interior structures). Semantic information is one of the main components in CityGML and 3D City Models, and provides important information for any analyses. However, more often than not, the semantic information is not available for the 3D city model due to the unstandardized modelling process. One of the examples is where a building is normally generated as one object (without specific feature layers such as Roof, Ground floor, Level 1, Level 2, Block A, Block B, etc). This research attempts to develop a method to improve the semantic data updating process by segmenting the 3D building into simpler parts which will make it easier for the users to select and update the semantic information. The methodology is implemented for 3D buildings in LoD2 where the buildings are generated without architectural details but with distinct roof structures. This paper also introduces hybrid semantic-geometric 3D segmentation method that deals with hierarchical segmentation of a 3D building based on its semantic value and surface characteristics, fitted by one of the predefined primitives. For future work, the segmentation method will be implemented as part of the change detection module that can detect any changes on the 3D buildings, store and retrieve semantic information of the changed structure, automatically updates the 3D models and visualize the results in a userfriendly graphical user interface (GUI).

  8. Geometric-model-free tracking of extended targets using 3D lidar measurements

    NASA Astrophysics Data System (ADS)

    Steinemann, Philipp; Klappstein, Jens; Dickmann, Juergen; von Hundelshausen, Felix; Wünsche, Hans-Joachim

    2012-06-01

    Tracking of extended targets in high definition, 360-degree 3D-LIDAR (Light Detection and Ranging) measurements is a challenging task and a current research topic. It is a key component in robotic applications, and is relevant to path planning and collision avoidance. This paper proposes a new method without a geometric model to simultaneously track and accumulate 3D-LIDAR measurements of an object. The method itself is based on a particle filter and uses an object-related local 3D grid for each object. No geometric object hypothesis is needed. Accumulation allows coping with occlusions. The prediction step of the particle filter is governed by a motion model consisting of a deterministic and a probabilistic part. Since this paper is focused on tracking ground vehicles, a bicycle model is used for the deterministic part. The probabilistic part depends on the current state of each particle. A function for calculating the current probability density function for state transition is developed. It is derived in detail and based on a database consisting of vehicle dynamics measurements over several hundreds of kilometers. The adaptive probability density function narrows down the gating area for measurement data association. The second part of the proposed method addresses weighting the particles with a cost function. Different 3D-griddependent cost functions are presented and evaluated. Evaluations with real 3D-LIDAR measurements show the performance of the proposed method. The results are also compared to ground truth data.

  9. 3D geometrical modelling of post-foliation deformations in metamorphic terrains (Syros, Cyclades, Greece)

    NASA Astrophysics Data System (ADS)

    Philippon, Mélody; Le Carlier de Veslud, Christian; Gueydan, Frédéric; Brun, Jean-Pierre; Caumon, Guillaume

    2015-09-01

    Superposed to ductile syn-metamorphic deformations, post-foliation deformations affect metamorphic units during their exhumation. Understanding the role of such deformations in the structuration of metamorphic units is key for understanding the tectonic evolution of convergence zones. We characterize post-foliations deformations using 3D modelling which is a first-order tool to describe complex geological structures, but a challenging task where based only on surface data. We propose a modelling procedure that combines fast draft models (interpolation of orientation data), with more complex ones where the structural context is better understood (implicit modelling), allowing us to build a 3D geometrical model of Syros Island blueschists (Cyclades), based on field data. With our approach, the 3D model is able to capture the complex present-day geometry of the island, mainly controlled by the superposition of three types of post-metamorphic deformations affecting the original metamorphic pile: i) a top-to-South ramp-flat extensional system that dominates the overall island structure, ii) large-scale folding of the metamorphic units associated with ramp-flat extensional system, and iii) steeply-dipping normal faults trending dominantly NNW-SSE and EW. The 3D surfaces produced by this method match outcrop data, are geologically consistent, and provide reasonable estimates of geological structures in poorly constrained areas.

  10. Matching Aerial Images to 3d Building Models Based on Context-Based Geometric Hashing

    NASA Astrophysics Data System (ADS)

    Jung, J.; Bang, K.; Sohn, G.; Armenakis, C.

    2016-06-01

    In this paper, a new model-to-image framework to automatically align a single airborne image with existing 3D building models using geometric hashing is proposed. As a prerequisite process for various applications such as data fusion, object tracking, change detection and texture mapping, the proposed registration method is used for determining accurate exterior orientation parameters (EOPs) of a single image. This model-to-image matching process consists of three steps: 1) feature extraction, 2) similarity measure and matching, and 3) adjustment of EOPs of a single image. For feature extraction, we proposed two types of matching cues, edged corner points representing the saliency of building corner points with associated edges and contextual relations among the edged corner points within an individual roof. These matching features are extracted from both 3D building and a single airborne image. A set of matched corners are found with given proximity measure through geometric hashing and optimal matches are then finally determined by maximizing the matching cost encoding contextual similarity between matching candidates. Final matched corners are used for adjusting EOPs of the single airborne image by the least square method based on co-linearity equations. The result shows that acceptable accuracy of single image's EOP can be achievable by the proposed registration approach as an alternative to labour-intensive manual registration process.

  11. Matching Aerial Images to 3D Building Models Using Context-Based Geometric Hashing.

    PubMed

    Jung, Jaewook; Sohn, Gunho; Bang, Kiin; Wichmann, Andreas; Armenakis, Costas; Kada, Martin

    2016-06-22

    A city is a dynamic entity, which environment is continuously changing over time. Accordingly, its virtual city models also need to be regularly updated to support accurate model-based decisions for various applications, including urban planning, emergency response and autonomous navigation. A concept of continuous city modeling is to progressively reconstruct city models by accommodating their changes recognized in spatio-temporal domain, while preserving unchanged structures. A first critical step for continuous city modeling is to coherently register remotely sensed data taken at different epochs with existing building models. This paper presents a new model-to-image registration method using a context-based geometric hashing (CGH) method to align a single image with existing 3D building models. This model-to-image registration process consists of three steps: (1) feature extraction; (2) similarity measure; and matching, and (3) estimating exterior orientation parameters (EOPs) of a single image. For feature extraction, we propose two types of matching cues: edged corner features representing the saliency of building corner points with associated edges, and contextual relations among the edged corner features within an individual roof. A set of matched corners are found with given proximity measure through geometric hashing, and optimal matches are then finally determined by maximizing the matching cost encoding contextual similarity between matching candidates. Final matched corners are used for adjusting EOPs of the single airborne image by the least square method based on collinearity equations. The result shows that acceptable accuracy of EOPs of a single image can be achievable using the proposed registration approach as an alternative to a labor-intensive manual registration process.

  12. Matching Aerial Images to 3D Building Models Using Context-Based Geometric Hashing

    PubMed Central

    Jung, Jaewook; Sohn, Gunho; Bang, Kiin; Wichmann, Andreas; Armenakis, Costas; Kada, Martin

    2016-01-01

    A city is a dynamic entity, which environment is continuously changing over time. Accordingly, its virtual city models also need to be regularly updated to support accurate model-based decisions for various applications, including urban planning, emergency response and autonomous navigation. A concept of continuous city modeling is to progressively reconstruct city models by accommodating their changes recognized in spatio-temporal domain, while preserving unchanged structures. A first critical step for continuous city modeling is to coherently register remotely sensed data taken at different epochs with existing building models. This paper presents a new model-to-image registration method using a context-based geometric hashing (CGH) method to align a single image with existing 3D building models. This model-to-image registration process consists of three steps: (1) feature extraction; (2) similarity measure; and matching, and (3) estimating exterior orientation parameters (EOPs) of a single image. For feature extraction, we propose two types of matching cues: edged corner features representing the saliency of building corner points with associated edges, and contextual relations among the edged corner features within an individual roof. A set of matched corners are found with given proximity measure through geometric hashing, and optimal matches are then finally determined by maximizing the matching cost encoding contextual similarity between matching candidates. Final matched corners are used for adjusting EOPs of the single airborne image by the least square method based on collinearity equations. The result shows that acceptable accuracy of EOPs of a single image can be achievable using the proposed registration approach as an alternative to a labor-intensive manual registration process. PMID:27338410

  13. Automated segmentation and geometrical modeling of the tricuspid aortic valve in 3D echocardiographic images.

    PubMed

    Pouch, Alison M; Wang, Hongzhi; Takabe, Manabu; Jackson, Benjamin M; Sehgal, Chandra M; Gorman, Joseph H; Gorman, Robert C; Yushkevich, Paul A

    2013-01-01

    The aortic valve has been described with variable anatomical definitions, and the consistency of 2D manual measurement of valve dimensions in medical image data has been questionable. Given the importance of image-based morphological assessment in the diagnosis and surgical treatment of aortic valve disease, there is considerable need to develop a standardized framework for 3D valve segmentation and shape representation. Towards this goal, this work integrates template-based medial modeling and multi-atlas label fusion techniques to automatically delineate and quantitatively describe aortic leaflet geometry in 3D echocardiographic (3DE) images, a challenging task that has been explored only to a limited extent. The method makes use of expert knowledge of aortic leaflet image appearance, generates segmentations with consistent topology, and establishes a shape-based coordinate system on the aortic leaflets that enables standardized automated measurements. In this study, the algorithm is evaluated on 11 3DE images of normal human aortic leaflets acquired at mid systole. The clinical relevance of the method is its ability to capture leaflet geometry in 3DE image data with minimal user interaction while producing consistent measurements of 3D aortic leaflet geometry.

  14. Space-time evolution of a growth fold (Betic Cordillera, Spain). Evidences from 3D geometrical modelling

    NASA Astrophysics Data System (ADS)

    Martin-Rojas, Ivan; Alfaro, Pedro; Estévez, Antonio

    2014-05-01

    We present a study that encompasses several software tools (iGIS©, ArcGIS©, Autocad©, etc.) and data (geological mapping, high resolution digital topographic data, high resolution aerial photographs, etc.) to create a detailed 3D geometric model of an active fault propagation growth fold. This 3D model clearly shows structural features of the analysed fold, as well as growth relationships and sedimentary patterns. The results obtained permit us to discuss the kinematics and structural evolution of the fold and the fault in time and space. The study fault propagation fold is the Crevillente syncline. This fold represents the northern limit of the Bajo Segura Basin, an intermontane basin in the Eastern Betic Cordillera (SE Spain) developed from upper Miocene on. 3D features of the Crevillente syncline, including growth pattern, indicate that limb rotation and, consequently, fault activity was higher during Messinian than during Tortonian; consequently, fault activity was also higher. From Pliocene on our data point that limb rotation and fault activity steadies or probably decreases. This in time evolution of the Crevillente syncline is not the same all along the structure; actually the 3D geometric model indicates that observed lateral heterogeneity is related to along strike variation of fault displacement.

  15. Urbanisation and 3d Spatial - a Geometric Approach

    NASA Astrophysics Data System (ADS)

    Duncan, E. E.; Rahman, A. Abdul

    2013-09-01

    Urbanisation creates immense competition for space, this may be attributed to an increase in population owing to domestic and external tourism. Most cities are constantly exploring all avenues in maximising its limited space. Hence, urban or city authorities need to plan, expand and use such three dimensional (3D) space above, on and below the city space. Thus, difficulties in property ownership and the geometric representation of the 3D city space is a major challenge. This research, investigates the concept of representing a geometric topological 3D spatial model capable of representing 3D volume parcels for man-made constructions above and below the 3D surface volume parcel. A review of spatial data models suggests that the 3D TIN (TEN) model is significant and can be used as a unified model. The concepts, logical and physical models of 3D TIN for 3D volumes using tetrahedrons as the base geometry is presented and implemented to show man-made constructions above and below the surface parcel within a user friendly graphical interface. Concepts for 3D topology and 3D analysis are discussed. Simulations of this model for 3D cadastre are implemented. This model can be adopted by most countries to enhance and streamline geometric 3D property ownership for urban centres. 3D TIN concept for spatial modelling can be adopted for the LA_Spatial part of the Land Administration Domain Model (LADM) (ISO/TC211, 2012), this satisfies the concept of 3D volumes.

  16. Static analysis of offshore risers with a geometrically-exact 3D beam model subjected to unilateral contact

    NASA Astrophysics Data System (ADS)

    Neto, Alfredo Gay; Martins, Clóvis A.; Pimenta, Paulo M.

    2014-01-01

    In offshore applications there are elements that can be modeled as long beams, such as umbilical cables, flexible and rigid pipes and hoses, immersed in the sea water, suspended from the floating unit to the seabed. The suspended part of these elements is named "riser" and is subjected to the ocean environment loads, such as waves and sea current. This work presents a structural geometrically-exact 3D beam model, discretized using the finite element method for riser modeling. An updated Lagrangian framework for the rotation parameterization has been used for the description of the exact kinematics. The goal is to perform a complete static analysis, considering the oceanic loads and the unilateral contact with the seabed, extending the current standard analysis for situations in which very large rotations occurs, in particular, large torsion. Details of the nonlinear 3D model and loads from oceanic environment are discussed, including the contact unilateral constraint.

  17. Thickness Reconstruction of Layers by 3D Geometrical Model to Characterize Caledonian Tectonic Complex and Data in Latvia

    NASA Astrophysics Data System (ADS)

    Ukass, J.; Saks, T.; Popovs, K.

    2012-04-01

    In present study we attempt to verify the 3D geological model, which has been built on a variety of heterogeneous data sources for the Baltic Basin (BB). Data describing the displacement along the faults and associated thickness changes of the syntectonic strata is sparse and reflects only regional relevance (Brangulis & Konsins 2002). Borehole logs provide most reliable and comprehensive data source for reconstructing the structural geology of the Latvia sedimentary cover as sufficient quality seismic data is available only for the local scale structures. Based on the thickness analysis of the boreholes rough resolution 3D geological tectonic block model was developed to deconstruct the geological structure of the Latvia Caledonian sedimentary sequence. MOSYS modeling system was used for the geological structure modeling, developed within the PUMA project (Sennikovs et al, 2011). Algorithmic genetic approach was applied to interpolate data of well logs as strata volume and sequentially to reconstruct the post-deformation situation. This approach allows modifying model construction in any step and all processes are fully documented and are repeatable. Geometrical model consists of 33 tectonic blocks bordered by the faults which were distributed by interpreting displacement amount of the blocks along the faults providing an opportunity to characterize common tectonic evolution. The study results indicate insignificant thickness change of the Ordovician and Silurian strata along the faults suggesting that major slip event along the faults occurred during the late Silurian and early Devonian, and some secondary fault reactivation during the middle Devonian Narva time. Uplift of the territory during this time is confirmed by the presence of the regional unconformity. Constructed rough resolution 3D geometrical model suggests shortening along the horizontal axis approximately 10 - 20% but most of the shortening has occurred in the central-west part of Latvia where it

  18. a Geometric Processing Workflow for Transforming Reality-Based 3d Models in Volumetric Meshes Suitable for Fea

    NASA Astrophysics Data System (ADS)

    Gonizzi Barsanti, S.; Guidi, G.

    2017-02-01

    Conservation of Cultural Heritage is a key issue and structural changes and damages can influence the mechanical behaviour of artefacts and buildings. The use of Finite Elements Methods (FEM) for mechanical analysis is largely used in modelling stress behaviour. The typical workflow involves the use of CAD 3D models made by Non-Uniform Rational B-splines (NURBS) surfaces, representing the ideal shape of the object to be simulated. Nowadays, 3D documentation of CH has been widely developed through reality-based approaches, but the models are not suitable for a direct use in FEA: the mesh has in fact to be converted to volumetric, and the density has to be reduced since the computational complexity of a FEA grows exponentially with the number of nodes. The focus of this paper is to present a new method aiming at generate the most accurate 3D representation of a real artefact from highly accurate 3D digital models derived from reality-based techniques, maintaining the accuracy of the high-resolution polygonal models in the solid ones. The approach proposed is based on a wise use of retopology procedures and a transformation of this model to a mathematical one made by NURBS surfaces suitable for being processed by volumetric meshers typically embedded in standard FEM packages. The strong simplification with little loss of consistency possible with the retopology step is used for maintaining as much coherence as possible between the original acquired mesh and the simplified model, creating in the meantime a topology that is more favourable for the automatic NURBS conversion.

  19. ROOT OO model to render multi-level 3-D geometrical objects via an OpenGL

    NASA Astrophysics Data System (ADS)

    Brun, Rene; Fine, Valeri; Rademakers, Fons

    2001-08-01

    This paper presents a set of C++ low-level classes to render 3D objects within ROOT-based frameworks. This allows developing a set of viewers with different properties the user can choose from to render one and the same 3D objects.

  20. Patient-specific geometrical modeling of orthopedic structures with high efficiency and accuracy for finite element modeling and 3D printing.

    PubMed

    Huang, Huajun; Xiang, Chunling; Zeng, Canjun; Ouyang, Hanbin; Wong, Kelvin Kian Loong; Huang, Wenhua

    2015-12-01

    We improved the geometrical modeling procedure for fast and accurate reconstruction of orthopedic structures. This procedure consists of medical image segmentation, three-dimensional geometrical reconstruction, and assignment of material properties. The patient-specific orthopedic structures reconstructed by this improved procedure can be used in the virtual surgical planning, 3D printing of real orthopedic structures and finite element analysis. A conventional modeling consists of: image segmentation, geometrical reconstruction, mesh generation, and assignment of material properties. The present study modified the conventional method to enhance software operating procedures. Patient's CT images of different bones were acquired and subsequently reconstructed to give models. The reconstruction procedures were three-dimensional image segmentation, modification of the edge length and quantity of meshes, and the assignment of material properties according to the intensity of gravy value. We compared the performance of our procedures to the conventional procedures modeling in terms of software operating time, success rate and mesh quality. Our proposed framework has the following improvements in the geometrical modeling: (1) processing time: (femur: 87.16 ± 5.90 %; pelvis: 80.16 ± 7.67 %; thoracic vertebra: 17.81 ± 4.36 %; P < 0.05); (2) least volume reduction (femur: 0.26 ± 0.06 %; pelvis: 0.70 ± 0.47, thoracic vertebra: 3.70 ± 1.75 %; P < 0.01) and (3) mesh quality in terms of aspect ratio (femur: 8.00 ± 7.38 %; pelvis: 17.70 ± 9.82 %; thoracic vertebra: 13.93 ± 9.79 %; P < 0.05) and maximum angle (femur: 4.90 ± 5.28 %; pelvis: 17.20 ± 19.29 %; thoracic vertebra: 3.86 ± 3.82 %; P < 0.05). Our proposed patient-specific geometrical modeling requires less operating time and workload, but the orthopedic structures were generated at a higher rate of success as compared with the conventional method. It is expected to benefit the surgical planning of orthopedic

  1. A Hybrid 3D Indoor Space Model

    NASA Astrophysics Data System (ADS)

    Jamali, Ali; Rahman, Alias Abdul; Boguslawski, Pawel

    2016-10-01

    GIS integrates spatial information and spatial analysis. An important example of such integration is for emergency response which requires route planning inside and outside of a building. Route planning requires detailed information related to indoor and outdoor environment. Indoor navigation network models including Geometric Network Model (GNM), Navigable Space Model, sub-division model and regular-grid model lack indoor data sources and abstraction methods. In this paper, a hybrid indoor space model is proposed. In the proposed method, 3D modeling of indoor navigation network is based on surveying control points and it is less dependent on the 3D geometrical building model. This research proposes a method of indoor space modeling for the buildings which do not have proper 2D/3D geometrical models or they lack semantic or topological information. The proposed hybrid model consists of topological, geometrical and semantical space.

  2. 3D printed, bio-inspired prototypes and analytical models for structured suture interfaces with geometrically-tuned deformation and failure behavior

    NASA Astrophysics Data System (ADS)

    Lin, Erica; Li, Yaning; Ortiz, Christine; Boyce, Mary C.

    2014-12-01

    Geometrically structured interfaces in nature possess enhanced, and often surprising, mechanical properties, and provide inspiration for materials design. This paper investigates the mechanics of deformation and failure mechanisms of suture interface designs through analytical models and experiments on 3D printed polymer physical prototypes. Suture waveforms with generalized trapezoidal geometries (trapezoidal, rectangular, anti-trapezoidal, and triangular) are studied and characterized by several important geometric parameters: the presence or absence of a bonded tip region, the tip angle, and the geometry. It is shown that a wide range (in some cases as great as an order of magnitude) in stiffness, strength, and toughness is achievable dependent on tip bonding, tip angle, and geometry. Suture interfaces with a bonded tip region exhibit a higher initial stiffness due to the greater load bearing by the skeletal teeth, a double peak in the stress-strain curve corresponding to the failure of the bonded tip and the failure of the slanted interface region or tooth, respectively, and an additional failure and toughening mechanism due to the failure of the bonded tip. Anti-trapezoidal geometries promote the greatest amplification of properties for suture interfaces with a bonded tip due the large tip interface area. The tip angle and geometry govern the stress distributions in the teeth and the ratio of normal to shear stresses in the interfacial layers, which together determine the failure mechanism of the interface and/or the teeth. Rectangular suture interfaces fail by simple shearing of the interfaces. Trapezoidal and triangular suture interfaces fail by a combination of shear and tensile normal stresses in the interface, leading to plastic deformation, cavitation events, and subsequent stretching of interface ligaments with mostly elastic deformation in the teeth. Anti-trapezoidal suture interfaces with small tip angles have high stress concentrations in the teeth

  3. Crowdsourcing Based 3d Modeling

    NASA Astrophysics Data System (ADS)

    Somogyi, A.; Barsi, A.; Molnar, B.; Lovas, T.

    2016-06-01

    Web-based photo albums that support organizing and viewing the users' images are widely used. These services provide a convenient solution for storing, editing and sharing images. In many cases, the users attach geotags to the images in order to enable using them e.g. in location based applications on social networks. Our paper discusses a procedure that collects open access images from a site frequently visited by tourists. Geotagged pictures showing the image of a sight or tourist attraction are selected and processed in photogrammetric processing software that produces the 3D model of the captured object. For the particular investigation we selected three attractions in Budapest. To assess the geometrical accuracy, we used laser scanner and DSLR as well as smart phone photography to derive reference values to enable verifying the spatial model obtained from the web-album images. The investigation shows how detailed and accurate models could be derived applying photogrammetric processing software, simply by using images of the community, without visiting the site.

  4. Tensor3D: A computer graphics program to simulate 3D real-time deformation and visualization of geometric bodies

    NASA Astrophysics Data System (ADS)

    Pallozzi Lavorante, Luca; Dirk Ebert, Hans

    2008-07-01

    Tensor3D is a geometric modeling program with the capacity to simulate and visualize in real-time the deformation, specified through a tensor matrix and applied to triangulated models representing geological bodies. 3D visualization allows the study of deformational processes that are traditionally conducted in 2D, such as simple and pure shears. Besides geometric objects that are immediately available in the program window, the program can read other models from disk, thus being able to import objects created with different open-source or proprietary programs. A strain ellipsoid and a bounding box are simultaneously shown and instantly deformed with the main object. The principal axes of strain are visualized as well to provide graphical information about the orientation of the tensor's normal components. The deformed models can also be saved, retrieved later and deformed again, in order to study different steps of progressive strain, or to make this data available to other programs. The shape of stress ellipsoids and the corresponding Mohr circles defined by any stress tensor can also be represented. The application was written using the Visualization ToolKit, a powerful scientific visualization library in the public domain. This development choice, allied to the use of the Tcl/Tk programming language, which is independent on the host computational platform, makes the program a useful tool for the study of geometric deformations directly in three dimensions in teaching as well as research activities.

  5. Assessment of the 3-d reconstruction and high-resolution geometrical modeling of the human skeletal trunk from 2-D radiographic images.

    PubMed

    Delorme, S; Petit, Y; de Guise, J A; Labelle, H; Aubin, C E; Dansereau, J

    2003-08-01

    This paper presents an in vivo validation of a method for the three-dimensional (3-D) high-resolution modeling of the human spine, rib cage, and pelvis for the study of spinal deformities. The method uses an adaptation of a standard close-range photogrammetry method called direct linear transformation to reconstruct the 3-D coordinates of anatomical landmarks from three radiographic images of the subject's trunk. It then deforms in 3-D 1-mm-resolution anatomical primitives (reference bones) obtained by serial computed tomography-scan reconstruction of a dry specimen. The free-form deformation is calculated using dual kriging equations. In vivo validation of this method on 40 scoliotic vertebrae gives an overall accuracy of 3.3 +/- 3.8 mm, making it an adequate tool for clinical studies and mechanical analysis purposes.

  6. Making Inexpensive 3-D Models

    ERIC Educational Resources Information Center

    Manos, Harry

    2016-01-01

    Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the "TPT" theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity…

  7. Debris Dispersion Model Using Java 3D

    NASA Technical Reports Server (NTRS)

    Thirumalainambi, Rajkumar; Bardina, Jorge

    2004-01-01

    This paper describes web based simulation of Shuttle launch operations and debris dispersion. Java 3D graphics provides geometric and visual content with suitable mathematical model and behaviors of Shuttle launch. Because the model is so heterogeneous and interrelated with various factors, 3D graphics combined with physical models provides mechanisms to understand the complexity of launch and range operations. The main focus in the modeling and simulation covers orbital dynamics and range safety. Range safety areas include destruct limit lines, telemetry and tracking and population risk near range. If there is an explosion of Shuttle during launch, debris dispersion is explained. The shuttle launch and range operations in this paper are discussed based on the operations from Kennedy Space Center, Florida, USA.

  8. Making Inexpensive 3-D Models

    NASA Astrophysics Data System (ADS)

    Manos, Harry

    2016-03-01

    Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the TPT theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity well tailored to specific class lessons. Most of the supplies are readily available in the home or at school: rubbing alcohol, a rag, two colors of spray paint, art brushes, and masking tape. The cost of these supplies, if you don't have them, is less than 20.

  9. Inferential modeling of 3D chromatin structure.

    PubMed

    Wang, Siyu; Xu, Jinbo; Zeng, Jianyang

    2015-04-30

    For eukaryotic cells, the biological processes involving regulatory DNA elements play an important role in cell cycle. Understanding 3D spatial arrangements of chromosomes and revealing long-range chromatin interactions are critical to decipher these biological processes. In recent years, chromosome conformation capture (3C) related techniques have been developed to measure the interaction frequencies between long-range genome loci, which have provided a great opportunity to decode the 3D organization of the genome. In this paper, we develop a new Bayesian framework to derive the 3D architecture of a chromosome from 3C-based data. By modeling each chromosome as a polymer chain, we define the conformational energy based on our current knowledge on polymer physics and use it as prior information in the Bayesian framework. We also propose an expectation-maximization (EM) based algorithm to estimate the unknown parameters of the Bayesian model and infer an ensemble of chromatin structures based on interaction frequency data. We have validated our Bayesian inference approach through cross-validation and verified the computed chromatin conformations using the geometric constraints derived from fluorescence in situ hybridization (FISH) experiments. We have further confirmed the inferred chromatin structures using the known genetic interactions derived from other studies in the literature. Our test results have indicated that our Bayesian framework can compute an accurate ensemble of 3D chromatin conformations that best interpret the distance constraints derived from 3C-based data and also agree with other sources of geometric constraints derived from experimental evidence in the previous studies. The source code of our approach can be found in https://github.com/wangsy11/InfMod3DGen.

  10. Summary on several key techniques in 3D geological modeling.

    PubMed

    Mei, Gang

    2014-01-01

    Several key techniques in 3D geological modeling including planar mesh generation, spatial interpolation, and surface intersection are summarized in this paper. Note that these techniques are generic and widely used in various applications but play a key role in 3D geological modeling. There are two essential procedures in 3D geological modeling: the first is the simulation of geological interfaces using geometric surfaces and the second is the building of geological objects by means of various geometric computations such as the intersection of surfaces. Discrete geometric surfaces that represent geological interfaces can be generated by creating planar meshes first and then spatially interpolating; those surfaces intersect and then form volumes that represent three-dimensional geological objects such as rock bodies. In this paper, the most commonly used algorithms of the key techniques in 3D geological modeling are summarized.

  11. Summary on Several Key Techniques in 3D Geological Modeling

    PubMed Central

    2014-01-01

    Several key techniques in 3D geological modeling including planar mesh generation, spatial interpolation, and surface intersection are summarized in this paper. Note that these techniques are generic and widely used in various applications but play a key role in 3D geological modeling. There are two essential procedures in 3D geological modeling: the first is the simulation of geological interfaces using geometric surfaces and the second is the building of geological objects by means of various geometric computations such as the intersection of surfaces. Discrete geometric surfaces that represent geological interfaces can be generated by creating planar meshes first and then spatially interpolating; those surfaces intersect and then form volumes that represent three-dimensional geological objects such as rock bodies. In this paper, the most commonly used algorithms of the key techniques in 3D geological modeling are summarized. PMID:24772029

  12. Vector algorithms for geometrically nonlinear 3D finite element analysis

    NASA Technical Reports Server (NTRS)

    Whitcomb, John D.

    1989-01-01

    Algorithms for geometrically nonlinear finite element analysis are presented which exploit the vector processing capability of the VPS-32, which is closely related to the CYBER 205. By manipulating vectors (which are long lists of numbers) rather than individual numbers, very high processing speeds are obtained. Long vector lengths are obtained without extensive replication or reordering by storage of intermediate results in strategic patterns at all stages of the computations. Comparisons of execution times with those from programs using either scalar or other vector programming techniques indicate that the algorithms presented are quite efficient.

  13. High Resolution 3d Modeling of the Behaim Globe

    NASA Astrophysics Data System (ADS)

    Menna, F.; Rizzi, A.; Nocerino, E.; Remondino, F.; Gruen, A.

    2012-07-01

    The article describes the 3D surveying and modeling of the Behaim globe, the oldest still existing and intact globe of the earth, preserved at the German National Museum of Nuremberg, Germany. The work is primarily performed using high-resolution digital images and automatic photogrammetric techniques. Triangulation-based laser scanning is also employed to fill some gaps in the derived image-based 3D geometry and perform geometric comparisons. Major problems are encountered in texture mapping. The 3D modeling project and the creation of high-resolution map-projections is performed for scientific, conservation, visualization and education purposes.

  14. 3D Printing of Molecular Models

    ERIC Educational Resources Information Center

    Gardner, Adam; Olson, Arthur

    2016-01-01

    Physical molecular models have played a valuable role in our understanding of the invisible nano-scale world. We discuss 3D printing and its use in producing models of the molecules of life. Complex biomolecular models, produced from 3D printed parts, can demonstrate characteristics of molecular structure and function, such as viral self-assembly,…

  15. 3D Microperfusion Model of ADPKD

    DTIC Science & Technology

    2015-10-01

    Stratasys 3D printer . PDMS was cast in the negative molds in order to create permanent biocompatible plastic masters (SmoothCast 310). All goals of task...1 AWARD NUMBER: W81XWH-14-1-0304 TITLE: 3D Microperfusion Model of ADPKD PRINCIPAL INVESTIGATOR: David L. Kaplan CONTRACTING ORGANIZATION...ADDRESS. 1. REPORT DATE October 2015 2. REPORT TYPE Annual Report 3. DATES COVERED 15 Sep 2014 - 14 Sep 2015 4. TITLE AND SUBTITLE 3D

  16. BEAMS3D Neutral Beam Injection Model

    SciTech Connect

    Lazerson, Samuel

    2014-04-14

    With the advent of applied 3D fi elds in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous velocity reduction, and pitch angle scattering are modeled with the ADAS atomic physics database [1]. Benchmark calculations are presented to validate the collisionless particle orbits, neutral beam injection model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields.

  17. Modeling cellular processes in 3D.

    PubMed

    Mogilner, Alex; Odde, David

    2011-12-01

    Recent advances in photonic imaging and fluorescent protein technology offer unprecedented views of molecular space-time dynamics in living cells. At the same time, advances in computing hardware and software enable modeling of ever more complex systems, from global climate to cell division. As modeling and experiment become more closely integrated we must address the issue of modeling cellular processes in 3D. Here, we highlight recent advances related to 3D modeling in cell biology. While some processes require full 3D analysis, we suggest that others are more naturally described in 2D or 1D. Keeping the dimensionality as low as possible reduces computational time and makes models more intuitively comprehensible; however, the ability to test full 3D models will build greater confidence in models generally and remains an important emerging area of cell biological modeling.

  18. RHOCUBE: 3D density distributions modeling code

    NASA Astrophysics Data System (ADS)

    Nikutta, Robert; Agliozzo, Claudia

    2016-11-01

    RHOCUBE models 3D density distributions on a discrete Cartesian grid and their integrated 2D maps. It can be used for a range of applications, including modeling the electron number density in LBV shells and computing the emission measure. The RHOCUBE Python package provides several 3D density distributions, including a powerlaw shell, truncated Gaussian shell, constant-density torus, dual cones, and spiralling helical tubes, and can accept additional distributions. RHOCUBE provides convenient methods for shifts and rotations in 3D, and if necessary, an arbitrary number of density distributions can be combined into the same model cube and the integration ∫ dz performed through the joint density field.

  19. NUBEAM developments and 3d halo modeling

    NASA Astrophysics Data System (ADS)

    Gorelenkova, M. V.; Medley, S. S.; Kaye, S. M.

    2012-10-01

    Recent developments related to the 3D halo model in NUBEAM code are described. To have a reliable halo neutral source for diagnostic simulation, the TRANSP/NUBEAM code has been enhanced with full implementation of ADAS atomic physic ground state and excited state data for hydrogenic beams and mixed species plasma targets. The ADAS codes and database provide the density and temperature dependence of the atomic data, and the collective nature of the state excitation process. To be able to populate 3D halo output with sufficient statistical resolution, the capability to control the statistics of fast ion CX modeling and for thermal halo launch has been added to NUBEAM. The 3D halo neutral model is based on modification and extension of the ``beam in box'' aligned 3d Cartesian grid that includes the neutral beam itself, 3D fast neutral densities due to CX of partially slowed down fast ions in the beam halo region, 3D thermal neutral densities due to CX deposition and fast neutral recapture source. More details on the 3D halo simulation design will be presented.

  20. Gis-Based Smart Cartography Using 3d Modeling

    NASA Astrophysics Data System (ADS)

    Malinverni, E. S.; Tassetti, A. N.

    2013-08-01

    3D City Models have evolved to be important tools for urban decision processes and information systems, especially in planning, simulation, analysis, documentation and heritage management. On the other hand existing and in use numerical cartography is often not suitable to be used in GIS because not geometrically and topologically correctly structured. The research aim is to 3D structure and organize a numeric cartography for GIS and turn it into CityGML standardized features. The work is framed around a first phase of methodological analysis aimed to underline which existing standard (like ISO and OGC rules) can be used to improve the quality requirement of a cartographic structure. Subsequently, from this technical specifics, it has been investigated the translation in formal contents, using an owner interchange software (SketchUp), to support some guide lines implementations to generate a GIS3D structured in GML3. It has been therefore predisposed a test three-dimensional numerical cartography (scale 1:500, generated from range data captured by 3D laser scanner), tested on its quality according to the previous standard and edited when and where necessary. Cad files and shapefiles are converted into a final 3D model (Google SketchUp model) and then exported into a 3D city model (CityGML LoD1/LoD2). The GIS3D structure has been managed in a GIS environment to run further spatial analysis and energy performance estimate, not achievable in a 2D environment. In particular geometrical building parameters (footprint, volume etc.) are computed and building envelop thermal characteristics are derived from. Lastly, a simulation is carried out to deal with asbestos and home renovating charges and show how the built 3D city model can support municipal managers with risk diagnosis of the present situation and development of strategies for a sustainable redevelop.

  1. 3D Modeling Engine Representation Summary Report

    SciTech Connect

    Steven Prescott; Ramprasad Sampath; Curtis Smith; Timothy Yang

    2014-09-01

    Computers have been used for 3D modeling and simulation, but only recently have computational resources been able to give realistic results in a reasonable time frame for large complex models. This summary report addressed the methods, techniques, and resources used to develop a 3D modeling engine to represent risk analysis simulation for advanced small modular reactor structures and components. The simulations done for this evaluation were focused on external events, specifically tsunami floods, for a hypothetical nuclear power facility on a coastline.

  2. Monocular accommodation condition in 3D display types through geometrical optics

    NASA Astrophysics Data System (ADS)

    Kim, Sung-Kyu; Kim, Dong-Wook; Park, Min-Chul; Son, Jung-Young

    2007-09-01

    Eye fatigue or strain phenomenon in 3D display environment is a significant problem for 3D display commercialization. The 3D display systems like eyeglasses type stereoscopic or auto-stereoscopic multiview, Super Multi-View (SMV), and Multi-Focus (MF) displays are considered for detail calculation about satisfaction level of monocular accommodation by geometrical optics calculation means. A lens with fixed focal length is used for experimental verification about numerical calculation of monocular defocus effect caused by accommodation at three different depths. And the simulation and experiment results consistently show relatively high level satisfaction about monocular accommodation at MF display condition. Additionally, possibility of monocular depth perception, 3D effect, at monocular MF display is discussed.

  3. BEAMS3D Neutral Beam Injection Model

    NASA Astrophysics Data System (ADS)

    McMillan, Matthew; Lazerson, Samuel A.

    2014-09-01

    With the advent of applied 3D fields in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous slowing down, and pitch angle scattering are modeled with the ADAS atomic physics database. Elementary benchmark calculations are presented to verify the collisionless particle orbits, NBI model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields. Notice: this manuscript has been authored by Princeton University under Contract Number DE-AC02-09CH11466 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.

  4. Geometric Bioinspired Networks for Recognition of 2-D and 3-D Low-Level Structures and Transformations.

    PubMed

    Bayro-Corrochano, Eduardo; Vazquez-Santacruz, Eduardo; Moya-Sanchez, Eduardo; Castillo-Munis, Efrain

    2016-10-01

    This paper presents the design of radial basis function geometric bioinspired networks and their applications. Until now, the design of neural networks has been inspired by the biological models of neural networks but mostly using vector calculus and linear algebra. However, these designs have never shown the role of geometric computing. The question is how biological neural networks handle complex geometric representations involving Lie group operations like rotations. Even though the actual artificial neural networks are biologically inspired, they are just models which cannot reproduce a plausible biological process. Until now researchers have not shown how, using these models, one can incorporate them into the processing of geometric computing. Here, for the first time in the artificial neural networks domain, we address this issue by designing a kind of geometric RBF using the geometric algebra framework. As a result, using our artificial networks, we show how geometric computing can be carried out by the artificial neural networks. Such geometric neural networks have a great potential in robot vision. This is the most important aspect of this contribution to propose artificial geometric neural networks for challenging tasks in perception and action. In our experimental analysis, we show the applicability of our geometric designs, and present interesting experiments using 2-D data of real images and 3-D screw axis data. In general, our models should be used to process different types of inputs, such as visual cues, touch (texture, elasticity, temperature), taste, and sound. One important task of a perception-action system is to fuse a variety of cues coming from the environment and relate them via a sensor-motor manifold with motor modules to carry out diverse reasoned actions.

  5. Degradation behaviors of geometric cues and mechanical properties in a 3D scaffold for tendon repair.

    PubMed

    Wu, Yang; Wong, Yoke San; Fuh, Jerry Ying Hsi

    2017-04-01

    A three-dimensional (3D) scaffold fabricated via electrohydrodynamic jet printing (E-jetting) and thermally uniaxial stretching, has been developed for tendon tissue regeneration in our previous study. In this study, more in-depth biological test showed that the aligned cell morphology guided by the anisotropic geometries of the 3D tendon scaffolds, leading to up-regulated tendious gene expression including collagen type I, decorin, tenascin-C, and biglycan, as compared to the electrospun scaffolds. Given the importance of geometric cues to the biological function of the scaffolds, the degradation behaviors of the 3D scaffolds were investigated. Results from accelerated hydrolysis showed that the E-jetted portion followed bulk-controlled erosion, while the unaixially stretched portion followed surface-controlled erosion. The 3D tendon scaffold exhibited consistency between the weight loss and the decline of mechanical properties, which indicated by a 65% decrease in mass with a corresponding 56% loss in ultimate tensile strength after degradation. This study not only reveals that the anisotropic geometries of 3D tendon scaffold could affect cell morphology and lead to desired gene expression toward tendon tissue but also gives an insight into how the degradation impacts geometric cues and mechanical properties of the as-fabricated scaffold. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1138-1149, 2017.

  6. 3-D Teaching Models for All

    ERIC Educational Resources Information Center

    Bradley, Joan; Farland-Smith, Donna

    2010-01-01

    Allowing a student to "see" through touch what other students see through a microscope can be a challenging task. Therefore, author Joan Bradley created three-dimensional (3-D) models with one student's visual impairment in mind. They are meant to benefit all students and can be used to teach common high school biology topics, including the…

  7. Constructing Arguments with 3-D Printed Models

    ERIC Educational Resources Information Center

    McConnell, William; Dickerson, Daniel

    2017-01-01

    In this article, the authors describe a fourth-grade lesson where 3-D printing technologies were not only a stimulus for engagement but also served as a modeling tool providing meaningful learning opportunities. Specifically, fourth-grade students construct an argument that animals' external structures function to support survival in a particular…

  8. Enhanced LOD Concepts for Virtual 3d City Models

    NASA Astrophysics Data System (ADS)

    Benner, J.; Geiger, A.; Gröger, G.; Häfele, K.-H.; Löwner, M.-O.

    2013-09-01

    Virtual 3D city models contain digital three dimensional representations of city objects like buildings, streets or technical infrastructure. Because size and complexity of these models continuously grow, a Level of Detail (LoD) concept effectively supporting the partitioning of a complete model into alternative models of different complexity and providing metadata, addressing informational content, complexity and quality of each alternative model is indispensable. After a short overview on various LoD concepts, this paper discusses the existing LoD concept of the CityGML standard for 3D city models and identifies a number of deficits. Based on this analysis, an alternative concept is developed and illustrated with several examples. It differentiates between first, a Geometric Level of Detail (GLoD) and a Semantic Level of Detail (SLoD), and second between the interior building and its exterior shell. Finally, a possible implementation of the new concept is demonstrated by means of an UML model.

  9. Model-based 3D SAR reconstruction

    NASA Astrophysics Data System (ADS)

    Knight, Chad; Gunther, Jake; Moon, Todd

    2014-06-01

    Three dimensional scene reconstruction with synthetic aperture radar (SAR) is desirable for target recognition and improved scene interpretability. The vertical aperture, which is critical to reconstruct 3D SAR scenes, is almost always sparsely sampled due to practical limitations, which creates an underdetermined problem. This papers explores 3D scene reconstruction using a convex model-based approach. The approach developed is demonstrated on 3D scenes, but can be extended to SAR reconstruction of sparsely sampled signals in the spatial and, or, frequency domains. The model-based approach enables knowledge-aided image formation (KAIF) by incorporating spatial, aspect, and sparsity magnitude terms into the image reconstruction. The incorporation of these terms, which are based on prior scene knowledge, will demonstrate improved results compared to traditional image formation algorithms. The SAR image formation problem is formulated as a second order cone program (SOCP) and the results are demonstrated on 3D scenes using simulated data and data from the GOTCHA data collect.1 The model-based results are contrasted against traditional backprojected images.

  10. Do-It-Yourself: 3D Models of Hydrogenic Orbitals through 3D Printing

    ERIC Educational Resources Information Center

    Griffith, Kaitlyn M.; de Cataldo, Riccardo; Fogarty, Keir H.

    2016-01-01

    Introductory chemistry students often have difficulty visualizing the 3-dimensional shapes of the hydrogenic electron orbitals without the aid of physical 3D models. Unfortunately, commercially available models can be quite expensive. 3D printing offers a solution for producing models of hydrogenic orbitals. 3D printing technology is widely…

  11. Perception-based shape retrieval for 3D building models

    NASA Astrophysics Data System (ADS)

    Zhang, Man; Zhang, Liqiang; Takis Mathiopoulos, P.; Ding, Yusi; Wang, Hao

    2013-01-01

    With the help of 3D search engines, a large number of 3D building models can be retrieved freely online. A serious disadvantage of most rotation-insensitive shape descriptors is their inability to distinguish between two 3D building models which are different at their main axes, but appear similar when one of them is rotated. To resolve this problem, we present a novel upright-based normalization method which not only correctly rotates such building models, but also greatly simplifies and accelerates the abstraction and the matching of building models' shape descriptors. Moreover, the abundance of architectural styles significantly hinders the effective shape retrieval of building models. Our research has shown that buildings with different designs are not well distinguished by the widely recognized shape descriptors for general 3D models. Motivated by this observation and to further improve the shape retrieval quality, a new building matching method is introduced and analyzed based on concepts found in the field of perception theory and the well-known Light Field descriptor. The resulting normalized building models are first classified using the qualitative shape descriptors of Shell and Unevenness which outline integral geometrical and topological information. These models are then put in on orderly fashion with the help of an improved quantitative shape descriptor which we will term as Horizontal Light Field Descriptor, since it assembles detailed shape characteristics. To accurately evaluate the proposed methodology, an enlarged building shape database which extends previous well-known shape benchmarks was implemented as well as a model retrieval system supporting inputs from 2D sketches and 3D models. Various experimental performance evaluation results have shown that, as compared to previous methods, retrievals employing the proposed matching methodology are faster and more consistent with human recognition of spatial objects. In addition these performance

  12. Illustrative visualization of 3D city models

    NASA Astrophysics Data System (ADS)

    Doellner, Juergen; Buchholz, Henrik; Nienhaus, Marc; Kirsch, Florian

    2005-03-01

    This paper presents an illustrative visualization technique that provides expressive representations of large-scale 3D city models, inspired by the tradition of artistic and cartographic visualizations typically found in bird"s-eye view and panoramic maps. We define a collection of city model components and a real-time multi-pass rendering algorithm that achieves comprehensible, abstract 3D city model depictions based on edge enhancement, color-based and shadow-based depth cues, and procedural facade texturing. Illustrative visualization provides an effective visual interface to urban spatial information and associated thematic information complementing visual interfaces based on the Virtual Reality paradigm, offering a huge potential for graphics design. Primary application areas include city and landscape planning, cartoon worlds in computer games, and tourist information systems.

  13. Repercussion of geometric and dynamic constraints on the 3D rendering quality in structurally adaptive multi-view shooting systems

    NASA Astrophysics Data System (ADS)

    Ali-Bey, Mohamed; Moughamir, Saïd; Manamanni, Noureddine

    2011-12-01

    in this paper a simulator of a multi-view shooting system with parallel optical axes and structurally variable configuration is proposed. The considered system is dedicated to the production of 3D contents for auto-stereoscopic visualization. The global shooting/viewing geometrical process, which is the kernel of this shooting system, is detailed and the different viewing, transformation and capture parameters are then defined. An appropriate perspective projection model is afterward derived to work out a simulator. At first, this latter is used to validate the global geometrical process in the case of a static configuration. Next, the simulator is used to show the limitations of a static configuration of this shooting system type by considering the case of dynamic scenes and then a dynamic scheme is achieved to allow a correct capture of this kind of scenes. After that, the effect of the different geometrical capture parameters on the 3D rendering quality and the necessity or not of their adaptation is studied. Finally, some dynamic effects and their repercussions on the 3D rendering quality of dynamic scenes are analyzed using error images and some image quantization tools. Simulation and experimental results are presented throughout this paper to illustrate the different studied points. Some conclusions and perspectives end the paper. [Figure not available: see fulltext.

  14. 3-D model-based vehicle tracking.

    PubMed

    Lou, Jianguang; Tan, Tieniu; Hu, Weiming; Yang, Hao; Maybank, Steven J

    2005-10-01

    This paper aims at tracking vehicles from monocular intensity image sequences and presents an efficient and robust approach to three-dimensional (3-D) model-based vehicle tracking. Under the weak perspective assumption and the ground-plane constraint, the movements of model projection in the two-dimensional image plane can be decomposed into two motions: translation and rotation. They are the results of the corresponding movements of 3-D translation on the ground plane (GP) and rotation around the normal of the GP, which can be determined separately. A new metric based on point-to-line segment distance is proposed to evaluate the similarity between an image region and an instantiation of a 3-D vehicle model under a given pose. Based on this, we provide an efficient pose refinement method to refine the vehicle's pose parameters. An improved EKF is also proposed to track and to predict vehicle motion with a precise kinematics model. Experimental results with both indoor and outdoor data show that the algorithm obtains desirable performance even under severe occlusion and clutter.

  15. Sensing and compressing 3-D models

    SciTech Connect

    Krumm, J.

    1998-02-01

    The goal of this research project was to create a passive and robust computer vision system for producing 3-D computer models of arbitrary scenes. Although the authors were unsuccessful in achieving the overall goal, several components of this research have shown significant potential. Of particular interest is the application of parametric eigenspace methods for planar pose measurement of partially occluded objects in gray-level images. The techniques presented provide a simple, accurate, and robust solution to the planar pose measurement problem. In addition, the representational efficiency of eigenspace methods used with gray-level features were successfully extended to binary features, which are less sensitive to illumination changes. The results of this research are presented in two papers that were written during the course of this project. The papers are included in sections 2 and 3. The first section of this report summarizes the 3-D modeling efforts.

  16. Vision models for 3D surfaces

    NASA Astrophysics Data System (ADS)

    Mitra, Sunanda

    1992-11-01

    Different approaches to computational stereo to represent human stereo vision have been developed over the past two decades. The Marr-Poggio theory of human stereo vision is probably the most widely accepted model of the human stereo vision. However, recently developed motion stereo models which use a sequence of images taken by either a moving camera or a moving object provide an alternative method of achieving multi-resolution matching without the use of Laplacian of Gaussian operators. While using image sequences, the baseline between two camera positions for a image pair is changed for the subsequent image pair so as to achieve different resolution for each image pair. Having different baselines also avoids the inherent occlusion problem in stereo vision models. The advantage of using multi-resolution images acquired by camera positioned at different baselines over those acquired by LOG operators is that one does not have to encounter spurious edges often created by zero-crossings in the LOG operated images. Therefore in designing a computer vision system, a motion stereo model is more appropriate than a stereo vision model. However, in some applications where only a stereo pair of images are available, recovery of 3D surfaces of natural scenes are possible in a computationally efficient manner by using cepstrum matching and regularization techniques. Section 2 of this paper describes a motion stereo model using multi-scale cepstrum matching for the detection of disparity between image pairs in a sequence of images and subsequent recovery of 3D surfaces from depth-map obtained by a non convergent triangulation technique. Section 3 presents a 3D surface recovery technique from a stereo pair using cepstrum matching for disparity detection and cubic B-splines for surface smoothing. Section 4 contains the results of 3D surface recovery using both of the techniques mentioned above. Section 5 discusses the merit of 2D cepstrum matching and cubic B

  17. Robust hashing for 3D models

    NASA Astrophysics Data System (ADS)

    Berchtold, Waldemar; Schäfer, Marcel; Rettig, Michael; Steinebach, Martin

    2014-02-01

    3D models and applications are of utmost interest in both science and industry. With the increment of their usage, their number and thereby the challenge to correctly identify them increases. Content identification is commonly done by cryptographic hashes. However, they fail as a solution in application scenarios such as computer aided design (CAD), scientific visualization or video games, because even the smallest alteration of the 3D model, e.g. conversion or compression operations, massively changes the cryptographic hash as well. Therefore, this work presents a robust hashing algorithm for 3D mesh data. The algorithm applies several different bit extraction methods. They are built to resist desired alterations of the model as well as malicious attacks intending to prevent correct allocation. The different bit extraction methods are tested against each other and, as far as possible, the hashing algorithm is compared to the state of the art. The parameters tested are robustness, security and runtime performance as well as False Acceptance Rate (FAR) and False Rejection Rate (FRR), also the probability calculation of hash collision is included. The introduced hashing algorithm is kept adaptive e.g. in hash length, to serve as a proper tool for all applications in practice.

  18. Fallon FORGE 3D Geologic Model

    SciTech Connect

    Doug Blankenship

    2016-03-01

    An x,y,z scattered data file for the 3D geologic model of the Fallon FORGE site. Model created in Earthvision by Dynamic Graphic Inc. The model was constructed with a grid spacing of 100 m. Geologic surfaces were extrapolated from the input data using a minimum tension gridding algorithm. The data file is tabular data in a text file, with lithology data associated with X,Y,Z grid points. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.

  19. 3D geometric split-merge segmentation of brain MRI datasets.

    PubMed

    Marras, Ioannis; Nikolaidis, Nikolaos; Pitas, Ioannis

    2014-05-01

    In this paper, a novel method for MRI volume segmentation based on region adaptive splitting and merging is proposed. The method, called Adaptive Geometric Split Merge (AGSM) segmentation, aims at finding complex geometrical shapes that consist of homogeneous geometrical 3D regions. In each volume splitting step, several splitting strategies are examined and the most appropriate is activated. A way to find the maximal homogeneity axis of the volume is also introduced. Along this axis, the volume splitting technique divides the entire volume in a number of large homogeneous 3D regions, while at the same time, it defines more clearly small homogeneous regions within the volume in such a way that they have greater probabilities of survival at the subsequent merging step. Region merging criteria are proposed to this end. The presented segmentation method has been applied to brain MRI medical datasets to provide segmentation results when each voxel is composed of one tissue type (hard segmentation). The volume splitting procedure does not require training data, while it demonstrates improved segmentation performance in noisy brain MRI datasets, when compared to the state of the art methods.

  20. Effect of Random Geometric Uncertainty on the Computational Design of a 3-D Flexible Wing

    NASA Technical Reports Server (NTRS)

    Gumbert, C. R.; Newman, P. A.; Hou, G. J.-W.

    2002-01-01

    The effect of geometric uncertainty due to statistically independent, random, normally distributed shape parameters is demonstrated in the computational design of a 3-D flexible wing. A first-order second-moment statistical approximation method is used to propagate the assumed input uncertainty through coupled Euler CFD aerodynamic / finite element structural codes for both analysis and sensitivity analysis. First-order sensitivity derivatives obtained by automatic differentiation are used in the input uncertainty propagation. These propagated uncertainties are then used to perform a robust design of a simple 3-D flexible wing at supercritical flow conditions. The effect of the random input uncertainties is shown by comparison with conventional deterministic design results. Sample results are shown for wing planform, airfoil section, and structural sizing variables.

  1. Chiral models: Geometrical aspects

    NASA Astrophysics Data System (ADS)

    Perelomov, A. M.

    1987-02-01

    Two-dimensional classical chiral models of field theory are considered, the main attention being paid on geometrical aspects of such theories. A characteristic feature of these models is that the interaction is inserted not by adding the interaction Lagrangian to the free field Lagrangian, but has a purely geometrical origin and is related to the inner curvature of the manifold. These models are in many respects analogous to non-Abelian gauge theories and as became clear recently, they are also important for the superstring theory which nowadays is the most probable candidate for a truly unified theory of all interactions including gravitation.

  2. 3D Model of Surfactant Replacement Therapy

    NASA Astrophysics Data System (ADS)

    Grotberg, James; Tai, Cheng-Feng; Filoche, Marcel

    2015-11-01

    Surfactant Replacement Therapy (SRT) involves instillation of a liquid-surfactant mixture directly into the lung airway tree. Though successful in neonatal applications, its use in adults had early success followed by failure. We present the first mathematical model of 3D SRT where a liquid plug propagates through the tree from forced inspiration. In two separate modeling steps, the plug first deposits a coating film on the airway wall which subtracts from its volume, a ``coating cost''. Then the plug splits unevenly at the airway bifurcation due to gravity. The steps are repeated until a plug ruptures or reaches the tree endpoint alveoli/acinus. The model generates 3D images of the resulting acinar distribution and calculates two global indexes, efficiency and homogeneity. Simulating published literature, the earlier successful adult SRT studies show comparatively good index values, while the later failed studies do not. Those unsuccessful studies used smaller dose volumes with higher concentration mixtures, apparently assuming a well mixed compartment. The model shows that adult lungs are not well mixed in SRT due to the coating cost and gravity effects. Returning to the higher dose volume protocols could save many thousands of lives annually in the US. Supported by NIH Grants HL85156, HL84370 and Agence Nationale de la Recherche, ANR no. 2010-BLAN-1119-05.

  3. 3-D model-based Bayesian classification

    SciTech Connect

    Soenneland, L.; Tenneboe, P.; Gehrmann, T.; Yrke, O.

    1994-12-31

    The challenging task of the interpreter is to integrate different pieces of information and combine them into an earth model. The sophistication level of this earth model might vary from the simplest geometrical description to the most complex set of reservoir parameters related to the geometrical description. Obviously the sophistication level also depend on the completeness of the available information. The authors describe the interpreter`s task as a mapping between the observation space and the model space. The information available to the interpreter exists in observation space and the task is to infer a model in model-space. It is well-known that this inversion problem is non-unique. Therefore any attempt to find a solution depend son constraints being added in some manner. The solution will obviously depend on which constraints are introduced and it would be desirable to allow the interpreter to modify the constraints in a problem-dependent manner. They will present a probabilistic framework that gives the interpreter the tools to integrate the different types of information and produce constrained solutions. The constraints can be adapted to the problem at hand.

  4. MOSSFRAC: An anisotropic 3D fracture model

    SciTech Connect

    Moss, W C; Levatin, J L

    2006-08-14

    Despite the intense effort for nearly half a century to construct detailed numerical models of plastic flow and plastic damage accumulation, models for describing fracture, an equally important damage mechanism still cannot describe basic fracture phenomena. Typical fracture models set the stress tensor to zero for tensile fracture and set the deviatoric stress tensor to zero for compressive fracture. One consequence is that the simple case of the tensile fracture of a cylinder under combined compressive radial and tensile axial loads is not modeled correctly. The experimental result is a cylinder that can support compressive radial loads, but no axial load, whereas, the typical numerical result is a cylinder with all stresses equal to zero. This incorrect modeling of fracture locally also has a global effect, because material that is fracturing produces stress release waves, which propagate from the fracture and influence the surrounding material. Consequently, it would be useful to have a model that can describe the stress relief and the resulting anisotropy due to fracture. MOSSFRAC is a material model that simulates three-dimensional tensile and shear fracture in initially isotropic elastic-plastic materials, although its framework is also amenable to initially anisotropic materials. It differs from other models by accounting for the effects of cracks on the constitutive response of the material, so that the previously described experiment, as well as complicated fracture scenarios are simulated more accurately. The model is implemented currently in the LLNL hydrocodes DYNA3D, PARADYN, and ALE3D. The purpose of this technical note is to present a complete qualitative description of the model and quantitative descriptions of salient features.

  5. 3D Echo Pilot Study of Geometric Left Ventricular Changes after Acute Myocardial Infarction

    PubMed Central

    Vieira, Marcelo Luiz Campos; Oliveira, Wercules Antonio; Cordovil, Adriana; Rodrigues, Ana Clara Tude; Mônaco, Cláudia Gianini; Afonso, Tânia; Lira Filho, Edgar Bezerra; Perin, Marco; Fischer, Cláudio Henrique; Morhy, Samira Saady

    2013-01-01

    Background Left ventricular remodeling (LVR) after AMI characterizes a factor of poor prognosis. There is little information in the literature on the LVR analyzed with three-dimensional echocardiography (3D ECHO). Objective To analyze, with 3D ECHO, the geometric and volumetric modifications of the left ventricle (VE) six months after AMI in patients subjected to percutaneous primary treatment. Methods Prospective study with 3D ECHO of 21 subjects (16 men, 56 ± 12 years-old), affected by AMI with ST segment elevation. The morphological and functional analysis (LV) with 3D ECHO (volumes, LVEF, 3D sphericity index) was carried out up to seven days and six months after the AMI. The LVR was considered for increase > 15% of the end diastolic volume of the LV (LVEDV) six months after the AMI, compared to the LVEDV up to seven days from the event. Results Eight (38%) patients have presented LVR. Echocardiographic measurements (n = 21 patients): I- up to seven days after the AMI: 1- LVEDV: 92.3 ± 22.3 mL; 2- LVEF: 0.51 ± 0.01; 3- sphericity index: 0.38 ± 0.05; II- after six months: 1- LVEDV: 107.3 ± 26.8 mL; 2- LVEF: 0.59 ± 0.01; 3- sphericity index: 0.31 ± 0.05. Correlation coefficient (r) between the sphericity index up to seven days after the AMI and the LVEDV at six months (n = 8) after the AMI: r: 0.74, p = 0.0007; (r) between the sphericity index six months after the AMI and the LVEDV at six months after the AMI: r: 0.85, p < 0.0001. Conclusion In this series, LVR has been observed in 38% of the patients six months after the AMI. The three-dimensional sphericity index has been associated to the occurrence of LVR. PMID:23740401

  6. 3D Stratigraphic Modeling of Central Aachen

    NASA Astrophysics Data System (ADS)

    Dong, M.; Neukum, C.; Azzam, R.; Hu, H.

    2010-05-01

    Since 1980s, advanced computer hardware and software technologies, as well as multidisciplinary research have provided possibilities to develop advanced three dimensional (3D) simulation software for geosciences application. Some countries, such as USA1) and Canada2) 3), have built up regional 3D geological models based on archival geological data. Such models have played huge roles in engineering geology2), hydrogeology2) 3), geothermal industry1) and so on. In cooperating with the Municipality of Aachen, the Department of Engineering Geology of RWTH Aachen University have built up a computer-based 3D stratigraphic model of 50 meter' depth for the center of Aachen, which is a 5 km by 7 km geologically complex area. The uncorrelated data from multi-resources, discontinuous nature and unconformable connection of the units are main challenges for geological modeling in this area. The reliability of 3D geological models largely depends on the quality and quantity of data. Existing 1D and 2D geological data were collected, including 1) approximately 6970 borehole data of different depth compiled in Microsoft Access database and MapInfo database; 2) a Digital Elevation Model (DEM); 3) geological cross sections; and 4) stratigraphic maps in 1m, 2m and 5m depth. Since acquired data are of variable origins, they were managed step by step. The main processes are described below: 1) Typing errors of borehole data were identified and the corrected data were exported to Variowin2.2 to distinguish duplicate points; 2) The surface elevation of borehole data was compared to the DEM, and differences larger than 3m were eliminated. Moreover, where elevation data missed, it was read from the DEM; 3) Considerable data were collected from municipal constructions, such as residential buildings, factories, and roads. Therefore, many boreholes are spatially clustered, and only one or two representative points were picked out in such areas; After above procedures, 5839 boreholes with -x

  7. Pragmatic geometric model evaluation

    NASA Astrophysics Data System (ADS)

    Pamer, Robert

    2015-04-01

    Quantification of subsurface model reliability is mathematically and technically demanding as there are many different sources of uncertainty and some of the factors can be assessed merely in a subjective way. For many practical applications in industry or risk assessment (e. g. geothermal drilling) a quantitative estimation of possible geometric variations in depth unit is preferred over relative numbers because of cost calculations for different scenarios. The talk gives an overview of several factors that affect the geometry of structural subsurface models that are based upon typical geological survey organization (GSO) data like geological maps, borehole data and conceptually driven construction of subsurface elements (e. g. fault network). Within the context of the trans-European project "GeoMol" uncertainty analysis has to be very pragmatic also because of different data rights, data policies and modelling software between the project partners. In a case study a two-step evaluation methodology for geometric subsurface model uncertainty is being developed. In a first step several models of the same volume of interest have been calculated by omitting successively more and more input data types (seismic constraints, fault network, outcrop data). The positions of the various horizon surfaces are then compared. The procedure is equivalent to comparing data of various levels of detail and therefore structural complexity. This gives a measure of the structural significance of each data set in space and as a consequence areas of geometric complexity are identified. These areas are usually very data sensitive hence geometric variability in between individual data points in these areas is higher than in areas of low structural complexity. Instead of calculating a multitude of different models by varying some input data or parameters as it is done by Monte-Carlo-simulations, the aim of the second step of the evaluation procedure (which is part of the ongoing work) is to

  8. Underwater 3d Modeling: Image Enhancement and Point Cloud Filtering

    NASA Astrophysics Data System (ADS)

    Sarakinou, I.; Papadimitriou, K.; Georgoula, O.; Patias, P.

    2016-06-01

    This paper examines the results of image enhancement and point cloud filtering on the visual and geometric quality of 3D models for the representation of underwater features. Specifically it evaluates the combination of effects from the manual editing of images' radiometry (captured at shallow depths) and the selection of parameters for point cloud definition and mesh building (processed in 3D modeling software). Such datasets, are usually collected by divers, handled by scientists and used for geovisualization purposes. In the presented study, have been created 3D models from three sets of images (seafloor, part of a wreck and a small boat's wreck) captured at three different depths (3.5m, 10m and 14m respectively). Four models have been created from the first dataset (seafloor) in order to evaluate the results from the application of image enhancement techniques and point cloud filtering. The main process for this preliminary study included a) the definition of parameters for the point cloud filtering and the creation of a reference model, b) the radiometric editing of images, followed by the creation of three improved models and c) the assessment of results by comparing the visual and the geometric quality of improved models versus the reference one. Finally, the selected technique is tested on two other data sets in order to examine its appropriateness for different depths (at 10m and 14m) and different objects (part of a wreck and a small boat's wreck) in the context of an ongoing research in the Laboratory of Photogrammetry and Remote Sensing.

  9. Bio-inspired design of geometrically interlocked 3D printed joints

    NASA Astrophysics Data System (ADS)

    Kumar, S.; Oliva, Noel; Kumar's Lab Team

    The morphology of the adhesive-adherend interface significantly affects the mechanical behavior of adhesive joints. As seen in some biocomposites like human skull, or the nacre of some bivalve molluscs' shells, a geometrically interlocking architecture of interfaces creates toughening and strengthening mechanisms enhancing the mechanical properties of the joint. In an attempt to characterize this mechanical interlocking mechanism, this study is focused on computational and experimental investigation of a single-lap joint with a very simple geometrically interlocked interface design in which both adherends have a square waveform configuration of the joining surfaces. This square waveform configuration contains a positive and a negative rectangular teeth per cycle in such a way that the joint is symmetric about the mid-bondlength. Both physical tests performed on 3D printed prototypes of joints and computational results indicate that the joints with square waveform design have higher strength and damage tolerance than those of joints with flat interface. In order to identify an optimal design configuration of this interface, a systematic parametric study is conducted by varying the geometric and material properties of the non-flat interface. This work was supported by Lockheed Martin (Award No: 12NZZ1).

  10. SB3D User Manual, Santa Barbara 3D Radiative Transfer Model

    SciTech Connect

    O'Hirok, William

    1999-01-01

    SB3D is a three-dimensional atmospheric and oceanic radiative transfer model for the Solar spectrum. The microphysics employed in the model are the same as used in the model SBDART. It is assumed that the user of SB3D is familiar with SBDART and IDL. SB3D differs from SBDART in that computations are conducted on media in three-dimensions rather than a single column (i.e. plane-parallel), and a stochastic method (Monte Carlo) is employed instead of a numerical approach (Discrete Ordinates) for estimating a solution to the radiative transfer equation. Because of these two differences between SB3D and SBDART, the input and running of SB3D is more unwieldy and requires compromises between model performance and computational expense. Hence, there is no one correct method for running the model and the user must develop a sense to the proper input and configuration of the model.

  11. Reservoir geology using 3D modelling tools

    SciTech Connect

    Dubrule, O.; Samson, P.; Segonds, D.

    1996-12-31

    The last decade has seen tremendous developments in the area of quantitative geological modelling. These developments have a significant impact on the current practice of constructing reservoir models. A structural model can first be constructed on the basis of depth-converted structural interpretations produced on a seismic interpretation workstation. Surfaces and faults can be represented as geological objects, and interactively modified. Once the tectonic framework has been obtained, intermediate stratigraphic surfaces can be constructed between the main structural surfaces. Within each layer, reservoir attributes can be represented using various techniques. Examples show how the distribution of different facies (i.e. from fine to coarse grain) can be represented, or how various depositional units (for instance channels, crevasses and lobes in a turbidite setting) can be modelled as geological {open_quotes}objects{close_quotes} with complex geometries. Elf Aquitaine, in close co-operation with the GOCAD project in Nancy (France) is investigating how geological models can be made more realistic by developing interactive functionalities. Examples show that, contrary to standard deterministic or geostatistical modelling techniques (which tend to be difficult to control) the use of new 3D tools allows the geologist to interactively modify geological surfaces (including faults) or volumetric properties. Thus, the sensitivity of various economic parameters (oil in place, connected volumes, reserves) to major geological uncertainties can be evaluated. It is argued that future breakthroughs in geological modelling techniques are likely to happen in the development of interactive approaches rather than in the research of new mathematical algorithms.

  12. Reservoir geology using 3D modelling tools

    SciTech Connect

    Dubrule, O. ); Samson, P. ); Segonds, D. )

    1996-01-01

    The last decade has seen tremendous developments in the area of quantitative geological modelling. These developments have a significant impact on the current practice of constructing reservoir models. A structural model can first be constructed on the basis of depth-converted structural interpretations produced on a seismic interpretation workstation. Surfaces and faults can be represented as geological objects, and interactively modified. Once the tectonic framework has been obtained, intermediate stratigraphic surfaces can be constructed between the main structural surfaces. Within each layer, reservoir attributes can be represented using various techniques. Examples show how the distribution of different facies (i.e. from fine to coarse grain) can be represented, or how various depositional units (for instance channels, crevasses and lobes in a turbidite setting) can be modelled as geological [open quotes]objects[close quotes] with complex geometries. Elf Aquitaine, in close co-operation with the GOCAD project in Nancy (France) is investigating how geological models can be made more realistic by developing interactive functionalities. Examples show that, contrary to standard deterministic or geostatistical modelling techniques (which tend to be difficult to control) the use of new 3D tools allows the geologist to interactively modify geological surfaces (including faults) or volumetric properties. Thus, the sensitivity of various economic parameters (oil in place, connected volumes, reserves) to major geological uncertainties can be evaluated. It is argued that future breakthroughs in geological modelling techniques are likely to happen in the development of interactive approaches rather than in the research of new mathematical algorithms.

  13. Scalable 3D GIS environment managed by 3D-XML-based modeling

    NASA Astrophysics Data System (ADS)

    Shi, Beiqi; Rui, Jianxun; Chen, Neng

    2008-10-01

    Nowadays, the namely 3D GIS technologies become a key factor in establishing and maintaining large-scale 3D geoinformation services. However, with the rapidly increasing size and complexity of the 3D models being acquired, a pressing needed for suitable data management solutions has become apparent. This paper outlines that storage and exchange of geospatial data between databases and different front ends like 3D models, GIS or internet browsers require a standardized format which is capable to represent instances of 3D GIS models, to minimize loss of information during data transfer and to reduce interface development efforts. After a review of previous methods for spatial 3D data management, a universal lightweight XML-based format for quick and easy sharing of 3D GIS data is presented. 3D data management based on XML is a solution meeting the requirements as stated, which can provide an efficient means for opening a new standard way to create an arbitrary data structure and share it over the Internet. To manage reality-based 3D models, this paper uses 3DXML produced by Dassault Systemes. 3DXML uses opening XML schemas to communicate product geometry, structure and graphical display properties. It can be read, written and enriched by standard tools; and allows users to add extensions based on their own specific requirements. The paper concludes with the presentation of projects from application areas which will benefit from the functionality presented above.

  14. Lujiatun Psittacosaurids: Understanding Individual and Taphonomic Variation Using 3D Geometric Morphometrics

    PubMed Central

    Hedrick, Brandon P.; Dodson, Peter

    2013-01-01

    Psittacosaurus is one of the most abundant and speciose genera in the Dinosauria, with fifteen named species. The genus is geographically and temporally widespread with large sample sizes of several of the nominal species allowing detailed analysis of intra- and interspecific variation. We present a reanalysis of three separate, coeval species within the Psittacosauridae; P. lujiatunensis, P. major, and Hongshanosaurus houi from the Lujiatun beds of the Yixian Formation, northeastern China, using three-dimensional geometric morphometrics on a sample set of thirty skulls in combination with a reevaluation of the proposed character states for each species. Using these complementary methods, we show that individual and taphonomic variation are the joint causes of a large range of variation among the skulls when they are plotted in a morphospace. Our results demonstrate that there is only one species of Psittacosaurus within the Lujiatun beds and that the three nominal species represent different taphomorphotypes of P. lujiatunensis. The wide range of geometric morphometric variation in a single species of Psittacosaurus implies that the range of variation found in other dinosaurian groups may also be related to taphonomic distortion rather than interspecific variation. As the morphospace is driven primarily by variation resulting from taphonomic distortion, this study demonstrates that the geometric morphometric approach can only be used with great caution to delineate interspecific variation in Psittacosaurus and likely other dinosaur groups without a complementary evaluation of character states. This study presents the first application of 3D geometric morphometrics to the dinosaurian morphospace and the first attempt to quantify taphonomic variation in dinosaur skulls. PMID:23950887

  15. Automated modeling of RNA 3D structure.

    PubMed

    Rother, Kristian; Rother, Magdalena; Skiba, Pawel; Bujnicki, Janusz M

    2014-01-01

    This chapter gives an overview over the current methods for automated modeling of RNA structures, with emphasis on template-based methods. The currently used approaches to RNA modeling are presented with a side view on the protein world, where many similar ideas have been used. Two main programs for automated template-based modeling are presented: ModeRNA assembling structures from fragments and MacroMoleculeBuilder performing a simulation to satisfy spatial restraints. Both approaches have in common that they require an alignment of the target sequence to a known RNA structure that is used as a modeling template. As a way to find promising template structures and to align the target and template sequences, we propose a pipeline combining the ParAlign and Infernal programs on RNA family data from Rfam. We also briefly summarize template-free methods for RNA 3D structure prediction. Typically, RNA structures generated by automated modeling methods require local or global optimization. Thus, we also discuss methods that can be used for local or global refinement of RNA structures.

  16. From Tls Point Clouds to 3d Models of Trees: a Comparison of Existing Algorithms for 3d Tree Reconstruction

    NASA Astrophysics Data System (ADS)

    Bournez, E.; Landes, T.; Saudreau, M.; Kastendeuch, P.; Najjar, G.

    2017-02-01

    3D models of tree geometry are important for numerous studies, such as for urban planning or agricultural studies. In climatology, tree models can be necessary for simulating the cooling effect of trees by estimating their evapotranspiration. The literature shows that the more accurate the 3D structure of a tree is, the more accurate microclimate models are. This is the reason why, since 2013, we have been developing an algorithm for the reconstruction of trees from terrestrial laser scanner (TLS) data, which we call TreeArchitecture. Meanwhile, new promising algorithms dedicated to tree reconstruction have emerged in the literature. In this paper, we assess the capacity of our algorithm and of two others -PlantScan3D and SimpleTree- to reconstruct the 3D structure of trees. The aim of this reconstruction is to be able to characterize the geometric complexity of trees, with different heights, sizes and shapes of branches. Based on a specific surveying workflow with a TLS, we have acquired dense point clouds of six different urban trees, with specific architectures, before reconstructing them with each algorithm. Finally, qualitative and quantitative assessments of the models are performed using reference tree reconstructions and field measurements. Based on this assessment, the advantages and the limits of every reconstruction algorithm are highlighted. Anyway, very satisfying results can be reached for 3D reconstructions of tree topology as well as of tree volume.

  17. Regional geothermal 3D modelling in Denmark

    NASA Astrophysics Data System (ADS)

    Poulsen, S. E.; Balling, N.; Bording, T. S.; Nielsen, S. B.

    2012-04-01

    In the pursuit of sustainable and low carbon emission energy sources, increased global attention has been given to the exploration and exploitation of geothermal resources within recent decades. In 2009 a national multi-disciplinary geothermal research project was established. As a significant part of this project, 3D temperature modelling is to be carried out, with special emphasis on temperatures of potential geothermal reservoirs in the Danish area. The Danish subsurface encompasses low enthalpy geothermal reservoirs of mainly Triassic and Jurassic age. Geothermal plants at Amager (Copenhagen) and Thisted (Northern Jutland) have the capacity of supplying the district heating network with up to 14 MW and 7 MW, respectively, by withdrawing warm pore water from the Gassum (Lower Jurassic/Upper Triassic) and Bunter (Lower Triassic) sandstone reservoirs, respectively. Explorative studies of the subsurface temperature regime typically are based on a combination of observations and modelling. In this study, the open-source groundwater modelling code MODFLOW is modified to simulate the subsurface temperature distribution in three dimensions by taking advantage of the mathematical similarity between saturated groundwater flow (Darcy flow) and heat conduction. A numerical model of the subsurface geology in Denmark is built and parameterized from lithological information derived from joint interpretation of seismic surveys and borehole information. Boundary conditions are constructed from knowledge about the heat flow from the Earth's interior and the shallow ground temperature. Matrix thermal conductivities have been estimated from analysis of high-resolution temperature logs measured in deep wells and porosity-depth relations are included using interpreted main lithologies. The model takes into account the dependency of temperature and pressure on thermal conductivity. Moreover, a transient model based correction of the paleoclimatic thermal disturbance caused by the

  18. Detailed 3D representations for object recognition and modeling.

    PubMed

    Zia, M Zeeshan; Stark, Michael; Schiele, Bernt; Schindler, Konrad

    2013-11-01

    Geometric 3D reasoning at the level of objects has received renewed attention recently in the context of visual scene understanding. The level of geometric detail, however, is typically limited to qualitative representations or coarse boxes. This is linked to the fact that today's object class detectors are tuned toward robust 2D matching rather than accurate 3D geometry, encouraged by bounding-box-based benchmarks such as Pascal VOC. In this paper, we revisit ideas from the early days of computer vision, namely, detailed, 3D geometric object class representations for recognition. These representations can recover geometrically far more accurate object hypotheses than just bounding boxes, including continuous estimates of object pose and 3D wireframes with relative 3D positions of object parts. In combination with robust techniques for shape description and inference, we outperform state-of-the-art results in monocular 3D pose estimation. In a series of experiments, we analyze our approach in detail and demonstrate novel applications enabled by such an object class representation, such as fine-grained categorization of cars and bicycles, according to their 3D geometry, and ultrawide baseline matching.

  19. PEGASUS. 3D Direct Simulation Monte Carlo Code Which Solves for Geometrics

    SciTech Connect

    Bartel, T.J.

    1998-12-01

    Pegasus is a 3D Direct Simulation Monte Carlo Code which solves for geometries which can be represented by bodies of revolution. Included are all the surface chemistry enhancements in the 2D code Icarus as well as a real vacuum pump model. The code includes multiple species transport.

  20. 3D Direct Simulation Monte Carlo Code Which Solves for Geometrics

    SciTech Connect

    Bartel, Timothy J.

    1998-01-13

    Pegasus is a 3D Direct Simulation Monte Carlo Code which solves for geometries which can be represented by bodies of revolution. Included are all the surface chemistry enhancements in the 2D code Icarus as well as a real vacuum pump model. The code includes multiple species transport.

  1. 3D Modelling of Kizildag Monument

    NASA Astrophysics Data System (ADS)

    Karauguz, Güngör; Kalayci, İbrahim; Öğütcü, Sermet

    2016-10-01

    The most important cultural property that the nations possess is their historical accumulation, and bringing these to light, taking measures to preserve them or at least maintain the continuity of transferring them to next generations by means of recent technic and technology, ought to be the business of present generations. Although, nowadays, intensive documentation and archiving studies are done by means of classical techniques, besides studies towards preserving historical objects, modelling one-to-one or scaled modelling were not possible until recently. Computing devices and the on-going reflection of this, which is acknowledged as digital technology, is widely used in many areas and makes it possible to document and archive historical works. Even virtual forms in quantitative environments can be transferred to next generations in a scaled and one-to-one modelled way. Within this scope, every single artefact categorization belonging to any era or civilization present in our country can be considered in separate study areas. Furthermore, any work or likewise can be evaluated in separate categories. Also, it is possible to construct travelable virtual 3D museums that make it possible to visit these artefacts. Under the auspices of these technologies, it is quite possible to construct single virtual indoor museums or also, at the final stage, a 3D travelable open-air museum, a platform or more precisely, to establish a data system that spreads all over the country on a broad spectrum. With a long-termed, significant and extensive study and a substantial organization, such a data system can be established, which also serves as a serious infrastructure for alternative tourism possibilities. Located beside a stepped altar and right above the Kizildag IV inscription, the offering pot is destructed and rolled away a few meters to the south slope of the mould. Every time visiting these artefacts with our undergraduate students, unfortunately, we observe more

  2. 3-D physical models of amitosis (cytokinesis).

    PubMed

    Cheng, Kang; Zou, Changhua

    2005-01-01

    Based on Newton's laws, extended Coulomb's law and published biological data, we develop our 3-D physical models of natural and normal amitosis (cytokinesis), for prokaryotes (bacterial cells) in M phase. We propose following hypotheses: Chromosome rings exclusion: No normally and naturally replicated chromosome rings (RCR) can occupy the same prokaryote, a bacterial cell. The RCR produce spontaneous and strong electromagnetic fields (EMF), that can be alternated environmentally, in protoplasm and cortex. The EMF is approximately a repulsive quasi-static electric (slowly variant and mostly electric) field (EF). The EF forces between the RCR are strong enough, and orderly accumulate contractile proteins that divide the procaryotes in the cell cortex of division plane or directly split the cell compartment envelope longitudinally. The radial component of the EF forces could also make furrows or cleavages of procaryotes. The EF distribution controls the protoplasm partition and completes the amitosis (cytokinesis). After the cytokinesis, the spontaneous and strong EF disappear because the net charge accumulation becomes weak, in the protoplasm. The exclusion is because the two sets of informative objects (RCR) have identical DNA codes information and they are electro magnetically identical, therefore they repulse from each other. We also compare divisions among eukaryotes, prokaryotes, mitochondria and chloroplasts and propose our hypothesis: The principles of our models are applied to divisions of mitochondria and chloroplasts of eucaryotes too because these division mechanisms are closer than others in a view of physics. Though we develop our model using 1 division plane (i.e., 1 cell is divided into 2 cells) as an example, the principle of our model is applied to the cases with multiple division planes (i.e., 1 cell is divided into multiple cells) too.

  3. Geometrically Nonlinear Static Analysis of 3D Trusses Using the Arc-Length Method

    NASA Technical Reports Server (NTRS)

    Hrinda, Glenn A.

    2006-01-01

    Rigorous analysis of geometrically nonlinear structures demands creating mathematical models that accurately include loading and support conditions and, more importantly, model the stiffness and response of the structure. Nonlinear geometric structures often contain critical points with snap-through behavior during the response to large loads. Studying the post buckling behavior during a portion of a structure's unstable load history may be necessary. Primary structures made from ductile materials will stretch enough prior to failure for loads to redistribute producing sudden and often catastrophic collapses that are difficult to predict. The responses and redistribution of the internal loads during collapses and possible sharp snap-back of structures have frequently caused numerical difficulties in analysis procedures. The presence of critical stability points and unstable equilibrium paths are major difficulties that numerical solutions must pass to fully capture the nonlinear response. Some hurdles still exist in finding nonlinear responses of structures under large geometric changes. Predicting snap-through and snap-back of certain structures has been difficult and time consuming. Also difficult is finding how much load a structure may still carry safely. Highly geometrically nonlinear responses of structures exhibiting complex snap-back behavior are presented and analyzed with a finite element approach. The arc-length method will be reviewed and shown to predict the proper response and follow the nonlinear equilibrium path through limit points.

  4. CityGML - Interoperable semantic 3D city models

    NASA Astrophysics Data System (ADS)

    Gröger, Gerhard; Plümer, Lutz

    2012-07-01

    CityGML is the international standard of the Open Geospatial Consortium (OGC) for the representation and exchange of 3D city models. It defines the three-dimensional geometry, topology, semantics and appearance of the most relevant topographic objects in urban or regional contexts. These definitions are provided in different, well-defined Levels-of-Detail (multiresolution model). The focus of CityGML is on the semantical aspects of 3D city models, its structures, taxonomies and aggregations, allowing users to employ virtual 3D city models for advanced analysis and visualization tasks in a variety of application domains such as urban planning, indoor/outdoor pedestrian navigation, environmental simulations, cultural heritage, or facility management. This is in contrast to purely geometrical/graphical models such as KML, VRML, or X3D, which do not provide sufficient semantics. CityGML is based on the Geography Markup Language (GML), which provides a standardized geometry model. Due to this model and its well-defined semantics and structures, CityGML facilitates interoperable data exchange in the context of geo web services and spatial data infrastructures. Since its standardization in 2008, CityGML has become used on a worldwide scale: tools from notable companies in the geospatial field provide CityGML interfaces. Many applications and projects use this standard. CityGML is also having a strong impact on science: numerous approaches use CityGML, particularly its semantics, for disaster management, emergency responses, or energy-related applications as well as for visualizations, or they contribute to CityGML, improving its consistency and validity, or use CityGML, particularly its different Levels-of-Detail, as a source or target for generalizations. This paper gives an overview of CityGML, its underlying concepts, its Levels-of-Detail, how to extend it, its applications, its likely future development, and the role it plays in scientific research. Furthermore, its

  5. Polygonal Shapes Detection in 3d Models of Complex Architectures

    NASA Astrophysics Data System (ADS)

    Benciolini, G. B.; Vitti, A.

    2015-02-01

    A sequential application of two global models defined on a variational framework is proposed for the detection of polygonal shapes in 3D models of complex architectures. As a first step, the procedure involves the use of the Mumford and Shah (1989) 1st-order variational model in dimension two (gridded height data are processed). In the Mumford-Shah model an auxiliary function detects the sharp changes, i.e., the discontinuities, of a piecewise smooth approximation of the data. The Mumford-Shah model requires the global minimization of a specific functional to simultaneously produce both the smooth approximation and its discontinuities. In the proposed procedure, the edges of the smooth approximation derived by a specific processing of the auxiliary function are then processed using the Blake and Zisserman (1987) 2nd-order variational model in dimension one (edges are processed in the plane). This second step permits to describe the edges of an object by means of piecewise almost-linear approximation of the input edges themselves and to detects sharp changes of the first-derivative of the edges so to detect corners. The Mumford-Shah variational model is used in two dimensions accepting the original data as primary input. The Blake-Zisserman variational model is used in one dimension for the refinement of the description of the edges. The selection among all the boundaries detected by the Mumford-Shah model of those that present a shape close to a polygon is performed by considering only those boundaries for which the Blake-Zisserman model identified discontinuities in their first derivative. The output of the procedure are hence shapes, coming from 3D geometric data, that can be considered as polygons. The application of the procedure is suitable for, but not limited to, the detection of objects such as foot-print of polygonal buildings, building facade boundaries or windows contours. v The procedure is applied to a height model of the building of the Engineering

  6. Multi-view and 3D deformable part models.

    PubMed

    Pepik, Bojan; Stark, Michael; Gehler, Peter; Schiele, Bernt

    2015-11-01

    As objects are inherently 3D, they have been modeled in 3D in the early days of computer vision. Due to the ambiguities arising from mapping 2D features to 3D models, 3D object representations have been neglected and 2D feature-based models are the predominant paradigm in object detection nowadays. While such models have achieved outstanding bounding box detection performance, they come with limited expressiveness, as they are clearly limited in their capability of reasoning about 3D shape or viewpoints. In this work, we bring the worlds of 3D and 2D object representations closer, by building an object detector which leverages the expressive power of 3D object representations while at the same time can be robustly matched to image evidence. To that end, we gradually extend the successful deformable part model [1] to include viewpoint information and part-level 3D geometry information, resulting in several different models with different level of expressiveness. We end up with a 3D object model, consisting of multiple object parts represented in 3D and a continuous appearance model. We experimentally verify that our models, while providing richer object hypotheses than the 2D object models, provide consistently better joint object localization and viewpoint estimation than the state-of-the-art multi-view and 3D object detectors on various benchmarks (KITTI [2] , 3D object classes [3] , Pascal3D+ [4] , Pascal VOC 2007 [5] , EPFL multi-view cars[6] ).

  7. 3D-GNOME: an integrated web service for structural modeling of the 3D genome.

    PubMed

    Szalaj, Przemyslaw; Michalski, Paul J; Wróblewski, Przemysław; Tang, Zhonghui; Kadlof, Michal; Mazzocco, Giovanni; Ruan, Yijun; Plewczynski, Dariusz

    2016-07-08

    Recent advances in high-throughput chromosome conformation capture (3C) technology, such as Hi-C and ChIA-PET, have demonstrated the importance of 3D genome organization in development, cell differentiation and transcriptional regulation. There is now a widespread need for computational tools to generate and analyze 3D structural models from 3C data. Here we introduce our 3D GeNOme Modeling Engine (3D-GNOME), a web service which generates 3D structures from 3C data and provides tools to visually inspect and annotate the resulting structures, in addition to a variety of statistical plots and heatmaps which characterize the selected genomic region. Users submit a bedpe (paired-end BED format) file containing the locations and strengths of long range contact points, and 3D-GNOME simulates the structure and provides a convenient user interface for further analysis. Alternatively, a user may generate structures using published ChIA-PET data for the GM12878 cell line by simply specifying a genomic region of interest. 3D-GNOME is freely available at http://3dgnome.cent.uw.edu.pl/.

  8. 3D-GNOME: an integrated web service for structural modeling of the 3D genome

    PubMed Central

    Szalaj, Przemyslaw; Michalski, Paul J.; Wróblewski, Przemysław; Tang, Zhonghui; Kadlof, Michal; Mazzocco, Giovanni; Ruan, Yijun; Plewczynski, Dariusz

    2016-01-01

    Recent advances in high-throughput chromosome conformation capture (3C) technology, such as Hi-C and ChIA-PET, have demonstrated the importance of 3D genome organization in development, cell differentiation and transcriptional regulation. There is now a widespread need for computational tools to generate and analyze 3D structural models from 3C data. Here we introduce our 3D GeNOme Modeling Engine (3D-GNOME), a web service which generates 3D structures from 3C data and provides tools to visually inspect and annotate the resulting structures, in addition to a variety of statistical plots and heatmaps which characterize the selected genomic region. Users submit a bedpe (paired-end BED format) file containing the locations and strengths of long range contact points, and 3D-GNOME simulates the structure and provides a convenient user interface for further analysis. Alternatively, a user may generate structures using published ChIA-PET data for the GM12878 cell line by simply specifying a genomic region of interest. 3D-GNOME is freely available at http://3dgnome.cent.uw.edu.pl/. PMID:27185892

  9. Femoral curvature in Neanderthals and modern humans: a 3D geometric morphometric analysis.

    PubMed

    De Groote, Isabelle

    2011-05-01

    Since their discovery, Neanderthals have been described as having a marked degree of anteroposterior curvature of the femoral shaft. Although initially believed to be pathological, subsequent discoveries of Neanderthal remains lead femoral curvature to be considered as a derived Neanderthal feature. A recent study on Neanderthals and middle and early Upper Palaeolithic modern humans found no differences in femoral curvature, but did not consider size-corrected curvature. Therefore, the objectives of this study were to use 3D morphometric landmark and semi-landmark analysis to quantify relative femoral curvature in Neanderthals, Upper Palaeolithic and recent modern humans, and to compare adult bone curvature as part of the overall femoral morphology among these populations. Comparisons among populations were made using geometric morphometrics (3D landmarks) and standard multivariate methods. Comparative material involved all available complete femora from Neanderthal and Upper Palaeolithic modern human, archaeological (Mesolithic, Neolithic, Medieval) and recent human populations representing a wide geographical and lifestyle range. There are significant differences in the anatomy of the femur between Neanderthals and modern humans. Neanderthals have more curved femora than modern humans. Early modern humans are most similar to recent modern humans in their anatomy. Femoral curvature is a good indicator of activity level and habitual loading of the lower limb, indicating higher activity levels in Neanderthals than modern humans. These differences contradict robusticity studies and the archaeological record, and would suggest that femoral morphology, and curvature in particular, in Neanderthals may not be explained by adult behavior alone and could be the result of genetic drift, natural selection or differences in behavior during ontogeny.

  10. 3D fast wavelet network model-assisted 3D face recognition

    NASA Astrophysics Data System (ADS)

    Said, Salwa; Jemai, Olfa; Zaied, Mourad; Ben Amar, Chokri

    2015-12-01

    In last years, the emergence of 3D shape in face recognition is due to its robustness to pose and illumination changes. These attractive benefits are not all the challenges to achieve satisfactory recognition rate. Other challenges such as facial expressions and computing time of matching algorithms remain to be explored. In this context, we propose our 3D face recognition approach using 3D wavelet networks. Our approach contains two stages: learning stage and recognition stage. For the training we propose a novel algorithm based on 3D fast wavelet transform. From 3D coordinates of the face (x,y,z), we proceed to voxelization to get a 3D volume which will be decomposed by 3D fast wavelet transform and modeled after that with a wavelet network, then their associated weights are considered as vector features to represent each training face . For the recognition stage, an unknown identity face is projected on all the training WN to obtain a new vector features after every projection. A similarity score is computed between the old and the obtained vector features. To show the efficiency of our approach, experimental results were performed on all the FRGC v.2 benchmark.

  11. A 3-D shape model of Interamnia

    NASA Astrophysics Data System (ADS)

    Sato, Isao

    2015-08-01

    A 3-D shape model of the sixth largest of the main belt asteroids, (704) Interamnia, is presented. The model is reproduced from its two stellar occultation observations and six lightcurves between 1969 and 2011. The first stellar occultation was the occultation of TYC 234500183 on 1996 December 17 observed from 13 sites in the USA. An elliptical cross section of (344.6±9.6km)×(306.2±9.1km), for position angle P=73.4±12.5 was fitted. The lightcurve around the occultation shows that the peak-to-peak amplitude was 0.04 mag. and the occultation phase was just before the minimum. The second stellar occultation was the occultation of HIP 036189 on 2003 March 23 observed from 39 sites in Japan and Hawaii. An elliptical cross section of (349.8±0.9km)×(303.7±1.7km), for position angle P=86.0±1.1 was fitted. A companion of 8.5 mag. of the occulted star was discovered whose separation is 12±2 mas (milli-arcseconds), P=148±11 . A combined analysis of rotational lightcurves and occultation chords can return more information than can be obtained with either technique alone. From follow-up photometric observations of the asteroid between 2003 and 2011, its rotation period is determined to be 8.728967167±0.00000007 hours, which is accurate enough to fix the rotation phases at other occultation events. The derived north pole is λ2000=259±8, β2000=-50±5 (retrograde rotation); the lengths of the three principal axes are 2a=361.8±2.8km, 2b=324.4±5.0km, 2c=297.3±3.5km, and the mean diameter is D=326.8±3.0km. Supposing the mass of Interamnia as (3.5±0.9)×10-11 solar masses, the density is then ρ=3.8±1.0 g cm-3.

  12. Anatomy-based 3D skeleton extraction from femur model.

    PubMed

    Gharenazifam, Mina; Arbabi, Ehsan

    2014-11-01

    Using 3D models of bones can highly improve accuracy and reliability of orthopaedic evaluation. However, it may impose excessive computational load. This article proposes a fully automatic method for extracting a compact model of the femur from its 3D model. The proposed method works by extracting a 3D skeleton based on the clinical parameters of the femur. Therefore, in addition to summarizing a 3D model of the bone, the extracted skeleton would preserve important clinical and anatomical information. The proposed method has been applied on 3D models of 10 femurs and the results have been evaluated for different resolutions of data.

  13. 3D facial expression recognition using maximum relevance minimum redundancy geometrical features

    NASA Astrophysics Data System (ADS)

    Rabiu, Habibu; Saripan, M. Iqbal; Mashohor, Syamsiah; Marhaban, Mohd Hamiruce

    2012-12-01

    In recent years, facial expression recognition (FER) has become an attractive research area, which besides the fundamental challenges, it poses, finds application in areas, such as human-computer interaction, clinical psychology, lie detection, pain assessment, and neurology. Generally the approaches to FER consist of three main steps: face detection, feature extraction and expression recognition. The recognition accuracy of FER hinges immensely on the relevance of the selected features in representing the target expressions. In this article, we present a person and gender independent 3D facial expression recognition method, using maximum relevance minimum redundancy geometrical features. The aim is to detect a compact set of features that sufficiently represents the most discriminative features between the target classes. Multi-class one-against-one SVM classifier was employed to recognize the seven facial expressions; neutral, happy, sad, angry, fear, disgust, and surprise. The average recognition accuracy of 92.2% was recorded. Furthermore, inter database homogeneity was investigated between two independent databases the BU-3DFE and UPM-3DFE the results showed a strong homogeneity between the two databases.

  14. Facial expression identification using 3D geometric features from Microsoft Kinect device

    NASA Astrophysics Data System (ADS)

    Han, Dongxu; Al Jawad, Naseer; Du, Hongbo

    2016-05-01

    Facial expression identification is an important part of face recognition and closely related to emotion detection from face images. Various solutions have been proposed in the past using different types of cameras and features. Microsoft Kinect device has been widely used for multimedia interactions. More recently, the device has been increasingly deployed for supporting scientific investigations. This paper explores the effectiveness of using the device in identifying emotional facial expressions such as surprise, smile, sad, etc. and evaluates the usefulness of 3D data points on a face mesh structure obtained from the Kinect device. We present a distance-based geometric feature component that is derived from the distances between points on the face mesh and selected reference points in a single frame. The feature components extracted across a sequence of frames starting and ending by neutral emotion represent a whole expression. The feature vector eliminates the need for complex face orientation correction, simplifying the feature extraction process and making it more efficient. We applied the kNN classifier that exploits a feature component based similarity measure following the principle of dynamic time warping to determine the closest neighbors. Preliminary tests on a small scale database of different facial expressions show promises of the newly developed features and the usefulness of the Kinect device in facial expression identification.

  15. 3D geometric morphometric analysis of the proximal epiphysis of the hominoid humerus

    PubMed Central

    Arias-Martorell, Julia; Potau, Josep Maria; Bello-Hellegouarch, Gaëlle; Pastor, Juan Francisco; Pérez-Pérez, Alejandro

    2012-01-01

    In this study we perform a three-dimensional geometric morphometric (3D GM) analysis of the proximal epiphysis of the humerus in extant great apes, including humans, in order to accurately describe the functional anatomical differences between these taxa. In addition, a fossil hominin specimen of Australopithecus afarensis was included in a multivariate GM analysis in order to test the potential of this methodological approach for making locomotor inferences from fossil remains. The results obtained show significant differences in proximal humeral morphology among the taxa studied, which had thus far largely remained unnoticed. Based on morphofunctional considerations, these anatomical differences can be correlated to differences in the locomotor repertoires of the taxa, thus confirming that the proximal humerus is suitable for constructing paleobiological inferences about locomotion. Modern humans display markedly divergent features, which set them apart from both the extant great apes and the fossil hominin A. afarensis. The morphology of the proximal epiphysis of the humerus of the latter more closely resembles that of the orangutans, thus suggesting that despite hindlimb adaptations to bipedalism, the forelimb of this taxon was still functionally involved in arboreal behaviors, such as climbing or suspension. PMID:22946496

  16. Geometrical Calibration of X-Ray Imaging With RGB Cameras for 3D Reconstruction.

    PubMed

    Albiol, Francisco; Corbi, Alberto; Albiol, Alberto

    2016-08-01

    We present a methodology to recover the geometrical calibration of conventional X-ray settings with the help of an ordinary video camera and visible fiducials that are present in the scene. After calibration, equivalent points of interest can be easily identifiable with the help of the epipolar geometry. The same procedure also allows the measurement of real anatomic lengths and angles and obtains accurate 3D locations from image points. Our approach completely eliminates the need for X-ray-opaque reference marks (and necessary supporting frames) which can sometimes be invasive for the patient, occlude the radiographic picture, and end up projected outside the imaging sensor area in oblique protocols. Two possible frameworks are envisioned: a spatially shifting X-ray anode around the patient/object and a moving patient that moves/rotates while the imaging system remains fixed. As a proof of concept, experiences with a device under test (DUT), an anthropomorphic phantom and a real brachytherapy session have been carried out. The results show that it is possible to identify common points with a proper level of accuracy and retrieve three-dimensional locations, lengths and shapes with a millimetric level of precision. The presented approach is simple and compatible with both current and legacy widespread diagnostic X-ray imaging deployments and it can represent a good and inexpensive alternative to other radiological modalities like CT.

  17. 3D Modeling Techniques for Print and Digital Media

    NASA Astrophysics Data System (ADS)

    Stephens, Megan Ashley

    In developing my thesis, I looked to gain skills using ZBrush to create 3D models, 3D scanning, and 3D printing. The models created compared the hearts of several vertebrates and were intended for students attending Comparative Vertebrate Anatomy. I used several resources to create a model of the human heart and was able to work from life while creating heart models from other vertebrates. I successfully learned ZBrush and 3D scanning, and successfully printed 3D heart models. ZBrush allowed me to create several intricate models for use in both animation and print media. The 3D scanning technique did not fit my needs for the project, but may be of use for later projects. I was able to 3D print using two different techniques as well.

  18. Elastic wave modelling in 3D heterogeneous media: 3D grid method

    NASA Astrophysics Data System (ADS)

    Jianfeng, Zhang; Tielin, Liu

    2002-09-01

    We present a new numerical technique for elastic wave modelling in 3D heterogeneous media with surface topography, which is called the 3D grid method in this paper. This work is an extension of the 2D grid method that models P-SV wave propagation in 2D heterogeneous media. Similar to the finite-element method in the discretization of a numerical mesh, the proposed scheme is flexible in incorporating surface topography and curved interfaces; moreover it satisfies the free-surface boundary conditions of 3D topography naturally. The algorithm, developed from a parsimonious staggered-grid scheme, solves the problem using integral equilibrium around each node, instead of satisfying elastodynamic differential equations at each node as in the conventional finite-difference method. The computational cost and memory requirements for the proposed scheme are approximately the same as those used by the same order finite-difference method. In this paper, a mixed tetrahedral and parallelepiped grid method is presented; and the numerical dispersion and stability criteria on the tetrahedral grid method and parallelepiped grid method are discussed in detail. The proposed scheme is successfully tested against an analytical solution for the 3D Lamb problem and a solution of the boundary method for the diffraction of a hemispherical crater. Moreover, examples of surface-wave propagation in an elastic half-space with a semi-cylindrical trench on the surface and 3D plane-layered model are presented.

  19. The 3D rocket combustor acoustics model

    NASA Technical Reports Server (NTRS)

    Priem, Richard J.; Breisacher, Kevin J.

    1992-01-01

    The theory and procedures for determining the characteristics of pressure oscillations in rocket engines with prescribed burning rate oscillations are presented. Analyses including radial and hub baffles and absorbers can be performed in one, two, and three dimensions. Pressure and velocity oscillations calculated using this procedure are presented for the SSME to show the influence of baffles and absorbers on the burning rate oscillations required to achieve neutral stability. Comparisons are made between the results obtained utilizing 1-D, 2-D, and 3-D assumptions with regards to capturing the physical phenomena of interest and computational requirements.

  20. 3D modeling based on CityEngine

    NASA Astrophysics Data System (ADS)

    Jia, Guangyin; Liao, Kaiju

    2017-03-01

    Currently, there are many 3D modeling softwares, like 3DMAX, AUTOCAD, and more populous BIM softwares represented by REVIT. CityEngine modeling software introduced in this paper can fully utilize the existing GIS data and combine other built models to make 3D modeling on internal and external part of buildings in a rapid and batch manner, so as to improve the 3D modeling efficiency.

  1. Real-time geometric scene estimation for RGBD images using a 3D box shape grammar

    NASA Astrophysics Data System (ADS)

    Willis, Andrew R.; Brink, Kevin M.

    2016-06-01

    This article describes a novel real-time algorithm for the purpose of extracting box-like structures from RGBD image data. In contrast to conventional approaches, the proposed algorithm includes two novel attributes: (1) it divides the geometric estimation procedure into subroutines having atomic incremental computational costs, and (2) it uses a generative "Block World" perceptual model that infers both concave and convex box elements from detection of primitive box substructures. The end result is an efficient geometry processing engine suitable for use in real-time embedded systems such as those on an UAVs where it is intended to be an integral component for robotic navigation and mapping applications.

  2. Single-Tooth Modeling for 3D Dental Model

    PubMed Central

    Yuan, Tianran; Liao, Wenhe; Dai, Ning; Cheng, Xiaosheng; Yu, Qing

    2010-01-01

    An integrated single-tooth modeling scheme is proposed for the 3D dental model acquired by optical digitizers. The cores of the modeling scheme are fusion regions extraction, single tooth shape restoration, and single tooth separation. According to the “valley” shape-like characters of the fusion regions between two adjoining teeth, the regions of the 3D dental model are analyzed and classified based on the minimum curvatures of the surface. The single tooth shape is restored according to the bioinformation along the hole boundary, which is generated after the fusion region being removed. By using the extracted boundary from the blending regions between the teeth and soft tissues as reference, the teeth can be separated from the 3D dental model one by one correctly. Experimental results show that the proposed method can achieve satisfying modeling results with high-degree approximation of the real tooth and meet the requirements of clinical oral medicine. PMID:20689718

  3. Quality assessment of watermarked 3D polygonal models

    NASA Astrophysics Data System (ADS)

    Funk, Wolfgang; Prasiswa, Jennifer

    2006-02-01

    In this paper, we present the design and results of subjective tests for evaluating the perceptibility of digital watermarks in 3D polygonal models. Based on the results we investigate different types of metrics with respect to their usefulness as predictors for the perceived visual quality of models that have been modified using a specific watermarking algorithm. We describe two experiments with models that have been watermarked using controlled free form deformations. The first experiment was conducted in supervised mode with still images of rendered models as stimuli and used the Two Alternative Forced Choice (2AFC) method. The second experiment was based on animated sequences and run in 2AFC mode with additional ratings of the perceived differences, but without assistance by the experimenter. We present a transparency analysis of the results and investigate the ability of image-based and geometry-based metrics to predict the perceived quality of the watermarked models. Our results show that the effectiveness of prediction depends on the type of model and in particular on the feature positions selected by the watermarking algorithm. The results of previous experiments with simplified polygonal models are confirmed, in that geometric measures are good predictors of quality ratings. We found that the symmetric Haussdorf distance is a promising candidate to evaluate the visual impact of the watermarking algorithm used in our experiments.

  4. Modeling and analysis of 3-D elongated shapes with applications to long bone morphometry

    SciTech Connect

    Burdin, V.; Roux, C.; Lefevre, C.; Stindel, E.

    1996-02-01

    This paper presents a geometric model to be used as a framework for the description and analysis of three-dimensional (3-D) elongated shapes. Elongated shapes can be decomposed into two different parts: a 3-D curve (the central axis) and a 3-D surface (the straight surface). The central axis is described in terms of curvature and torsion. A novel concept of torsion image is introduced which allows the user to study the torsion of some relevant 3-D structures such as the medulla of long bones, without computing the third derivative. The description of the straight surface is based on an ordered set of Fourier Descriptors (FD`s), each set representing a 2-D slice of the structure. These descriptors possess completeness, continuity, and stability properties, and some geometrical invariancies. A polar diagram is built which contains the anatomical information of the straight surface and can be used as a tool for the analysis and discrimination of 3-D structures. A technique for the reconstruction of the 3-D surface from the model`s two components is presented. Various applications to the analysis of long bone structures, such as the ulna and radius, are derived from the model, namely, data compression, comparison of 3-D shapes, segmentation into 3-D primitives, and torsion and curvature analysis. The relevance of the method to morphometry and to clinical applications is discussed.

  5. 3D tumor models: history, advances and future perspectives.

    PubMed

    Benien, Parul; Swami, Archana

    2014-05-01

    Evaluation of cancer therapeutics by utilizing 3D tumor models, before clinical studies, could be more advantageous than conventional 2D tumor models (monolayer cultures). The 3D systems mimic the tumor microenvironment more closely than 2D systems. The following review discusses the various 3D tumor models present today with the advantages and limitations of each. 3D tumor models replicate the elements of a tumor microenvironment such as hypoxia, necrosis, angiogenesis and cell adhesion. The review introduces application of techniques such as microfluidics, imaging and tissue engineering to improve the 3D tumor models. Despite their tremendous potential to better screen chemotherapeutics, 3D tumor models still have a long way to go before they are used commonly as in vitro tumor models in pharmaceutical industrial research.

  6. Investigation of surface wave amplitudes in 3-D velocity and 3-D Q models

    NASA Astrophysics Data System (ADS)

    Ruan, Y.; Zhou, Y.

    2010-12-01

    It has been long recognized that seismic amplitudes depend on both wave speed structures and anelasticity (Q) structures. However, the effects of lateral heterogeneities in wave speed and Q structures on seismic amplitudes has not been well understood. We investigate the effects of 3-D wave speed and 3-D anelasticity (Q) structures on surface-wave amplitudes based upon wave propagation simulations of twelve globally-distributed earthquakes and 801 stations in Earth models with and without lateral heterogeneities in wave speed and anelasticity using a Spectral Element Method (SEM). Our tomographic-like 3-D Q models are converted from a velocity model S20RTS using a set of reasonable mineralogical parameters, assuming lateral perturbations in both velocity and Q are due to temperature perturbations. Surface-wave amplitude variations of SEM seismograms are measured in the period range of 50--200 s using boxcar taper, cosine taper and Slepian multi-tapers. We calculate ray-theoretical predictions of surface-wave amplitude perturbations due to elastic focusing, attenuation, and anelastic focusing which respectively depend upon the second spatial derivative (''roughness'') of perturbations in phase velocity, 1/Q, and the roughness of perturbations in 1/Q. Both numerical experiments and theoretical calculations show that (1) for short-period (~ 50 s) surface waves, the effects of amplitude attenuation due to 3-D Q structures are comparable with elastic focusing effects due to 3-D wave speed structures; and (2) for long-period (> 100 s) surface waves, the effects of attenuation become much weaker than elastic focusing; and (3) elastic focusing effects are correlated with anelastic focusing at all periods due to the correlation between velocity and Q models; and (4) amplitude perturbations are depend on measurement techniques and therefore cannot be directly compared with ray-theoretical predictions because ray theory does not account for the effects of measurement

  7. Model-based vision using geometric hashing

    NASA Astrophysics Data System (ADS)

    Akerman, Alexander, III; Patton, Ronald

    1991-04-01

    The Geometric Hashing technique developed by the NYU Courant Institute has been applied to various automatic target recognition applications. In particular, I-MATH has extended the hashing algorithm to perform automatic target recognition ofsynthetic aperture radar (SAR) imagery. For this application, the hashing is performed upon the geometric locations of dominant scatterers. In addition to being a robust model-based matching algorithm -- invariant under translation, scale, and 3D rotations of the target -- hashing is of particular utility because it can still perform effective matching when the target is partially obscured. Moreover, hashing is very amenable to a SIMD parallel processing architecture, and thus potentially realtime implementable.

  8. 3D Face modeling using the multi-deformable method.

    PubMed

    Hwang, Jinkyu; Yu, Sunjin; Kim, Joongrock; Lee, Sangyoun

    2012-09-25

    In this paper, we focus on the problem of the accuracy performance of 3D face modeling techniques using corresponding features in multiple views, which is quite sensitive to feature extraction errors. To solve the problem, we adopt a statistical model-based 3D face modeling approach in a mirror system consisting of two mirrors and a camera. The overall procedure of our 3D facial modeling method has two primary steps: 3D facial shape estimation using a multiple 3D face deformable model and texture mapping using seamless cloning that is a type of gradient-domain blending. To evaluate our method's performance, we generate 3D faces of 30 individuals and then carry out two tests: accuracy test and robustness test. Our method shows not only highly accurate 3D face shape results when compared with the ground truth, but also robustness to feature extraction errors. Moreover, 3D face rendering results intuitively show that our method is more robust to feature extraction errors than other 3D face modeling methods. An additional contribution of our method is that a wide range of face textures can be acquired by the mirror system. By using this texture map, we generate realistic 3D face for individuals at the end of the paper.

  9. 3D geometrical inspection of complex geometry parts using a novel laser triangulation sensor and a robot.

    PubMed

    Brosed, Francisco Javier; Aguilar, Juan José; Guillomía, David; Santolaria, Jorge

    2011-01-01

    This article discusses different non contact 3D measuring strategies and presents a model for measuring complex geometry parts, manipulated through a robot arm, using a novel vision system consisting of a laser triangulation sensor and a motorized linear stage. First, the geometric model incorporating an automatic simple module for long term stability improvement will be outlined in the article. The new method used in the automatic module allows the sensor set up, including the motorized linear stage, for the scanning avoiding external measurement devices. In the measurement model the robot is just a positioning of parts with high repeatability. Its position and orientation data are not used for the measurement and therefore it is not directly "coupled" as an active component in the model. The function of the robot is to present the various surfaces of the workpiece along the measurement range of the vision system, which is responsible for the measurement. Thus, the whole system is not affected by the robot own errors following a trajectory, except those due to the lack of static repeatability. For the indirect link between the vision system and the robot, the original model developed needs only one first piece measuring as a "zero" or master piece, known by its accurate measurement using, for example, a Coordinate Measurement Machine. The strategy proposed presents a different approach to traditional laser triangulation systems on board the robot in order to improve the measurement accuracy, and several important cues for self-recalibration are explored using only a master piece. Experimental results are also presented to demonstrate the technique and the final 3D measurement accuracy.

  10. Vel-IO 3D: A tool for 3D velocity model construction, optimization and time-depth conversion in 3D geological modeling workflow

    NASA Astrophysics Data System (ADS)

    Maesano, Francesco E.; D'Ambrogi, Chiara

    2017-02-01

    We present Vel-IO 3D, a tool for 3D velocity model creation and time-depth conversion, as part of a workflow for 3D model building. The workflow addresses the management of large subsurface dataset, mainly seismic lines and well logs, and the construction of a 3D velocity model able to describe the variation of the velocity parameters related to strong facies and thickness variability and to high structural complexity. Although it is applicable in many geological contexts (e.g. foreland basins, large intermountain basins), it is particularly suitable in wide flat regions, where subsurface structures have no surface expression. The Vel-IO 3D tool is composed by three scripts, written in Python 2.7.11, that automate i) the 3D instantaneous velocity model building, ii) the velocity model optimization, iii) the time-depth conversion. They determine a 3D geological model that is consistent with the primary geological constraints (e.g. depth of the markers on wells). The proposed workflow and the Vel-IO 3D tool have been tested, during the EU funded Project GeoMol, by the construction of the 3D geological model of a flat region, 5700 km2 in area, located in the central part of the Po Plain. The final 3D model showed the efficiency of the workflow and Vel-IO 3D tool in the management of large amount of data both in time and depth domain. A 4 layer-cake velocity model has been applied to a several thousand (5000-13,000 m) thick succession, with 15 horizons from Triassic up to Pleistocene, complicated by a Mesozoic extensional tectonics and by buried thrusts related to Southern Alps and Northern Apennines.

  11. 3D Modelling of X-pinches.

    NASA Astrophysics Data System (ADS)

    Ciardi, A.; Chittenden, J. P.; Lebedev, S. V.; Bland, S. N.; Jennings, C. A.

    2003-10-01

    X-pinch produced plasmas are an intense source of soft x-rays generated by passing a large, fast rising current through two or more thin metallic wires crossed in the shape of <93>an "X". During the current pulse, the plasma is pinched at the crossing point where a dense Z-pinch plasma column develops. Further compression produces micron sized x-ray hot spots with energy densities in excess of ˜10^24 eV cm-3. We present 3D resistive magnetohydrodynamic simulations of two- and four-wire X-pinches for a variety of wire materials. The simulations naturally follow the evolution of the X-pinch: jet-like structures on axis, formation of a Z-pinch and its subsequent rapid evolution and production of x-ray hot spots. The effects of wire material and wire number are studied with particular consideration to the relationship between the magnetic confinement and radiative cooling mechanisms, which ultimately determine the complex behaviour of the X-pinch.

  12. Comparing a quasi-3D to a full 3D nearshore circulation model: SHORECIRC and ROMS

    USGS Publications Warehouse

    Haas, K.A.; Warner, J.C.

    2009-01-01

    Predictions of nearshore and surf zone processes are important for determining coastal circulation, impacts of storms, navigation, and recreational safety. Numerical modeling of these systems facilitates advancements in our understanding of coastal changes and can provide predictive capabilities for resource managers. There exists many nearshore coastal circulation models, however they are mostly limited or typically only applied as depth integrated models. SHORECIRC is an established surf zone circulation model that is quasi-3D to allow the effect of the variability in the vertical structure of the currents while maintaining the computational advantage of a 2DH model. Here we compare SHORECIRC to ROMS, a fully 3D ocean circulation model which now includes a three dimensional formulation for the wave-driven flows. We compare the models with three different test applications for: (i) spectral waves approaching a plane beach with an oblique angle of incidence; (ii) monochromatic waves driving longshore currents in a laboratory basin; and (iii) monochromatic waves on a barred beach with rip channels in a laboratory basin. Results identify that the models are very similar for the depth integrated flows and qualitatively consistent for the vertically varying components. The differences are primarily the result of the vertically varying radiation stress utilized by ROMS and the utilization of long wave theory for the radiation stress formulation in vertical varying momentum balance by SHORECIRC. The quasi-3D model is faster, however the applicability of the fully 3D model allows it to extend over a broader range of processes, temporal, and spatial scales. ?? 2008 Elsevier Ltd.

  13. a Fast Method for Measuring the Similarity Between 3d Model and 3d Point Cloud

    NASA Astrophysics Data System (ADS)

    Zhang, Zongliang; Li, Jonathan; Li, Xin; Lin, Yangbin; Zhang, Shanxin; Wang, Cheng

    2016-06-01

    This paper proposes a fast method for measuring the partial Similarity between 3D Model and 3D point Cloud (SimMC). It is crucial to measure SimMC for many point cloud-related applications such as 3D object retrieval and inverse procedural modelling. In our proposed method, the surface area of model and the Distance from Model to point Cloud (DistMC) are exploited as measurements to calculate SimMC. Here, DistMC is defined as the weighted distance of the distances between points sampled from model and point cloud. Similarly, Distance from point Cloud to Model (DistCM) is defined as the average distance of the distances between points in point cloud and model. In order to reduce huge computational burdens brought by calculation of DistCM in some traditional methods, we define SimMC as the ratio of weighted surface area of model to DistMC. Compared to those traditional SimMC measuring methods that are only able to measure global similarity, our method is capable of measuring partial similarity by employing distance-weighted strategy. Moreover, our method is able to be faster than other partial similarity assessment methods. We demonstrate the superiority of our method both on synthetic data and laser scanning data.

  14. Visualization of 3D Geological Models on Google Earth

    NASA Astrophysics Data System (ADS)

    Choi, Y.; Um, J.; Park, M.

    2013-05-01

    Google Earth combines satellite imagery, aerial photography, thematic maps and various data sets to make a three-dimensional (3D) interactive image of the world. Currently, Google Earth is a popular visualization tool in a variety of fields and plays an increasingly important role not only for private users in daily life, but also for scientists, practitioners, policymakers and stakeholders in research and application. In this study, a method to visualize 3D geological models on Google Earth is presented. COLLAborative Design Activity (COLLADA, an open standard XML schema for establishing interactive 3D applications) was used to represent different 3D geological models such as borehole, fence section, surface-based 3D volume and 3D grid by triangle meshes (a set of triangles connected by their common edges or corners). In addition, we designed Keyhole Markup Language (KML, the XML-based scripting language of Google Earth) codes to import the COLLADA files into the 3D render window of Google Earth. The method was applied to the Grosmont formation in Alberta, Canada. The application showed that the combination of COLLADA and KML enables Google Earth to effectively visualize 3D geological structures and properties.; Visualization of the (a) boreholes, (b) fence sections, (c) 3D volume model and (d) 3D grid model of Grossmont formation on Google Earth

  15. Automatic paper sliceform design from 3D solid models.

    PubMed

    Le-Nguyen, Tuong-Vu; Low, Kok-Lim; Ruiz, Conrado; Le, Sang N

    2013-11-01

    A paper sliceform or lattice-style pop-up is a form of papercraft that uses two sets of parallel paper patches slotted together to make a foldable structure. The structure can be folded flat, as well as fully opened (popped-up) to make the two sets of patches orthogonal to each other. Automatic design of paper sliceforms is still not supported by existing computational models and remains a challenge. We propose novel geometric formulations of valid paper sliceform designs that consider the stability, flat-foldability and physical realizability of the designs. Based on a set of sufficient construction conditions, we also present an automatic algorithm for generating valid sliceform designs that closely depict the given 3D solid models. By approximating the input models using a set of generalized cylinders, our method significantly reduces the search space for stable and flat-foldable sliceforms. To ensure the physical realizability of the designs, the algorithm automatically generates slots or slits on the patches such that no two cycles embedded in two different patches are interlocking each other. This guarantees local pairwise assembility between patches, which is empirically shown to lead to global assembility. Our method has been demonstrated on a number of example models, and the output designs have been successfully made into real paper sliceforms.

  16. A 3D Geometry Model Search Engine to Support Learning

    ERIC Educational Resources Information Center

    Tam, Gary K. L.; Lau, Rynson W. H.; Zhao, Jianmin

    2009-01-01

    Due to the popularity of 3D graphics in animation and games, usage of 3D geometry deformable models increases dramatically. Despite their growing importance, these models are difficult and time consuming to build. A distance learning system for the construction of these models could greatly facilitate students to learn and practice at different…

  17. [Potentials of 3D-modeling in reconstructive orbital surgery].

    PubMed

    Butsan, S B; Khokhlachev, S B; Ĭigitaliev, Sh N; Zaiakin, Ia A

    2012-01-01

    A technique of bone reconstructive surgery of orbitofrontonasomalar region using 3D-modeling based on multispiral computer tomography data is presented. The efficacy of intraoperative templates created using 3D-modeling was showed for harvesting and modeling of bone calvarial autografts. The steps of reconstructive procedure are explained in details for repair of medial and inferior orbital fractures.

  18. Computational modeling of RNA 3D structures and interactions.

    PubMed

    Dawson, Wayne K; Bujnicki, Janusz M

    2016-04-01

    RNA molecules have key functions in cellular processes beyond being carriers of protein-coding information. These functions are often dependent on the ability to form complex three-dimensional (3D) structures. However, experimental determination of RNA 3D structures is difficult, which has prompted the development of computational methods for structure prediction from sequence. Recent progress in 3D structure modeling of RNA and emerging approaches for predicting RNA interactions with ions, ligands and proteins have been stimulated by successes in protein 3D structure modeling.

  19. Error analysis and system implementation for structured light stereo vision 3D geometric detection in large scale condition

    NASA Astrophysics Data System (ADS)

    Qi, Li; Zhang, Xuping; Wang, Jiaqi; Zhang, Yixin; Wang, Shun; Zhu, Fan

    2012-11-01

    Stereo vision based 3D metrology technique is an effective approach for relatively large scale object's 3D geometric detection. In this paper, we present a specified image capture system, which implements LVDS interface embedded CMOS sensor and CAN bus to ensure synchronous trigger and exposure. We made an error analysis for structured light vision measurement in large scale condition, based on which we built and tested the system prototype both indoor and outfield. The result shows that the system is very suitable for large scale metrology applications.

  20. San Francisco Bay test case for 3-D model verification

    USGS Publications Warehouse

    Smith, Peter E.

    1994-01-01

    This paper describes a field test case for 3-D hydrodynamic model verification using data from Carquinez Strait in San Francisco Bay, California. It will be disseminated by the ASCE Computational Hydraulics task committee on 3-D Free-Surface Hydrodynamic Model Verifications during late 1994.

  1. Geometric modeling of pelvic organs with thickness

    NASA Astrophysics Data System (ADS)

    Bay, T.; Chen, Z.-W.; Raffin, R.; Daniel, M.; Joli, P.; Feng, Z.-Q.; Bellemare, M.-E.

    2012-03-01

    Physiological changes in the spatial configuration of the internal organs in the abdomen can induce different disorders that need surgery. Following the complexity of the surgical procedure, mechanical simulations are necessary but the in vivo factor makes complicate the study of pelvic organs. In order to determine a realistic behavior of these organs, an accurate geometric model associated with a physical modeling is therefore required. Our approach is integrated in the partnership between a geometric and physical module. The Geometric Modeling seeks to build a continuous geometric model: from a dataset of 3D points provided by a Segmentation step, surfaces are created through a B-spline fitting process. An energy function is built to measure the bidirectional distance between surface and data. This energy is minimized with an alternate iterative Hoschek-like method. A thickness is added with an offset formulation, and the geometric model is finally exported in a hexahedral mesh. Afterward, the Physical Modeling tries to calculate the properties of the soft tissues to simulate the organs displacements. The physical parameters attached to the data are determined with a feedback loop between finite-elements deformations and ground-truth acquisition (dynamic MRI).

  2. An Automatic Registration Algorithm for 3D Maxillofacial Model

    NASA Astrophysics Data System (ADS)

    Qiu, Luwen; Zhou, Zhongwei; Guo, Jixiang; Lv, Jiancheng

    2016-09-01

    3D image registration aims at aligning two 3D data sets in a common coordinate system, which has been widely used in computer vision, pattern recognition and computer assisted surgery. One challenging problem in 3D registration is that point-wise correspondences between two point sets are often unknown apriori. In this work, we develop an automatic algorithm for 3D maxillofacial models registration including facial surface model and skull model. Our proposed registration algorithm can achieve a good alignment result between partial and whole maxillofacial model in spite of ambiguous matching, which has a potential application in the oral and maxillofacial reparative and reconstructive surgery. The proposed algorithm includes three steps: (1) 3D-SIFT features extraction and FPFH descriptors construction; (2) feature matching using SAC-IA; (3) coarse rigid alignment and refinement by ICP. Experiments on facial surfaces and mandible skull models demonstrate the efficiency and robustness of our algorithm.

  3. Interactive mapping on 3-D terrain models

    NASA Astrophysics Data System (ADS)

    Bernardin, T.; Cowgill, E.; Gold, R.; Hamann, B.; Kreylos, O.; Schmitt, A.

    2006-10-01

    We present an interactive, real-time mapping system for use with digital elevation models and remotely sensed multispectral imagery that aids geoscientists in the creation and interpretation of geologic/neotectonic maps at length scales of 10 m to 1000 km. Our system provides a terrain visualization of the surface of the Earth or other terrestrial planets by displaying a virtual terrain model generated from a digital elevation model overlain by a color texture generated from orthophotos or satellite imagery. We use a quadtree-based, multiresolution display method to render in real time high-resolution virtual terrain models that span large spatial regions. The system allows users to measure the orientations of geologic surfaces and record their observations by drawing lines directly on the virtual terrain model. In addition, interpretive surfaces can be generated from these drawings and displayed to facilitate understanding of the three-dimensional geometry of geologic surfaces. The main strength of our system is the combination of real-time rendering and interactive mapping performed directly on the virtual terrain model with the ability to navigate the scene while changing viewpoints arbitrarily during mapping. User studies and comparisons with commercially available mapping software show that our system improves mapping accuracy and efficiency and also yields observations that cannot be made with existing systems.

  4. Extending 3D city models with legal information

    NASA Astrophysics Data System (ADS)

    Frank, A. U.; Fuhrmann, T.; Navratil, G.

    2012-10-01

    3D city models represent existing physical objects and their topological and functional relations. In everyday life the rights and responsibilities connected to these objects, primarily legally defined rights and obligations but also other socially and culturally established rights, are of importance. The rights and obligations are defined in various laws and it is often difficult to identify the rules applicable for a certain case. The existing 2D cadastres show civil law rights and obligations and plans to extend them to provide information about public law restrictions for land use are in several countries under way. It is tempting to design extensions to the 3D city models to provide information about legal rights in 3D. The paper analyses the different types of information that are needed to reduce conflicts and to facilitate decisions about land use. We identify the role 3D city models augmented with planning information in 3D can play, but do not advocate a general conversion from 2D to 3D for the legal cadastre. Space is not anisotropic and the up/down dimension is practically very different from the two dimensional plane - this difference must be respected when designing spatial information systems. The conclusions are: (1) continue the current regime for ownership of apartments, which is not ownership of a 3D volume, but co-ownership of a building with exclusive use of some rooms; such exclusive use rights could be shown in a 3D city model; (2) ownership of 3D volumes for complex and unusual building situations can be reported in a 3D city model, but are not required everywhere; (3) indicate restrictions for land use and building in 3D city models, with links to the legal sources.

  5. Opportunity Landing Spot Panorama (3-D Model)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The rocky outcrop traversed by the Mars Exploration Rover Opportunity is visible in this three-dimensional model of the rover's landing site. Opportunity has acquired close-up images along the way, and scientists are using the rover's instruments to closely examine portions of interest. The white fragments that look crumpled near the center of the image are portions of the airbags. Distant scenery is displayed on a spherical backdrop or 'billboard' for context. Artifacts near the top rim of the crater are a result of the transition between the three-dimensional model and the billboard. Portions of the terrain model lacking sufficient data appear as blank spaces or gaps, colored reddish-brown for better viewing. This image was generated using special software from NASA's Ames Research Center and a mosaic of images taken by the rover's panoramic camera.

    [figure removed for brevity, see original site] Click on image for larger view

    The rocky outcrop traversed by the Mars Exploration Rover Opportunity is visible in this zoomed-in portion of a three-dimensional model of the rover's landing site. Opportunity has acquired close-up images along the way, and scientists are using the rover's instruments to closely examine portions of interest. The white fragments that look crumpled near the center of the image are portions of the airbags. Distant scenery is displayed on a spherical backdrop or 'billboard' for context. Artifacts near the top rim of the crater are a result of the transition between the three-dimensional model and the billboard. Portions of the terrain model lacking sufficient data appear as blank spaces or gaps, colored reddish-brown for better viewing. This image was generated using special software from NASA's Ames Research Center and a mosaic of images taken by the rover's panoramic camera.

  6. Venusian Applications of 3D Convection Modeling

    NASA Technical Reports Server (NTRS)

    Bonaccorso, Timary Annie

    2011-01-01

    This study models mantle convection on Venus using the 'cubed sphere' code OEDIPUS, which models one-sixth of the planet in spherical geometry. We are attempting to balance internal heating, bottom mantle viscosity, and temperature difference across Venus' mantle, in order to create a realistic model that matches with current planetary observations. We also have begun to run both lower and upper mantle simulations to determine whether layered (as opposed to whole-mantle) convection might produce more efficient heat transfer, as well as to model coronae formation in the upper mantle. Upper mantle simulations are completed using OEDIPUS' Cartesian counterpart, JOCASTA. This summer's central question has been how to define a mantle plume. Traditionally, we have defined a hot plume the region with temperature at or above 40% of the difference between the maximum and horizontally averaged temperature, and a cold plume as the region with 40% of the difference between the minimum and average temperature. For less viscous cases (1020 Pa?s), the plumes generated by that definition lacked vigor, displaying buoyancies 1/100th of those found in previous, higher viscosity simulations (1021 Pa?s). As the mantle plumes with large buoyancy flux are most likely to produce topographic uplift and volcanism, the low viscosity cases' plumes may not produce observable deformation. In an effort to eliminate the smallest plumes, we experimented with different lower bound parameters and temperature percentages.

  7. RELAP5-3D Compressor Model

    SciTech Connect

    James E. Fisher; Cliff B. Davis; Walter L. Weaver

    2005-06-01

    A compressor model has been implemented in the RELAP5-3D© code. The model is similar to that of the existing pump model, and performs the same function on a gas as the pump performs on a single-phase or two-phase fluid. The compressor component consists of an inlet junction and a control volume, and optionally, an outlet junction. This feature permits cascading compressor components in series. The equations describing the physics of the compressor are derived from first principles. These equations are used to obtain the head, the torque, and the energy dissipation. Compressor performance is specified using a map, specific to the design of the machine, in terms of the ratio of outlet-to-inlet total (or stagnation) pressure and adiabatic efficiency as functions of rotational velocity and flow rate. The input quantities are specified in terms of dimensionless variables, which are corrected to stagnation density and stagnation sound speed. A small correction was formulated for the input of efficiency to account for the error introduced by assumption of constant density when integrating the momentum equation. Comparison of the results of steady-state operation of the compressor model to those of the MIT design calculation showed excellent agreement for both pressure ratio and power.

  8. Global Magnetospheric Modeling of 3D Reconnection

    NASA Technical Reports Server (NTRS)

    Spicer, Daniel S.

    1999-01-01

    A review of approaches to the global modeling of the terrestrial magnetosphere, how these approaches are utilized to interpret satellite data, and how these approaches have been successful at predicting magnetospheric phenomena will be presented. In addition, the importance of the ionospheric boundary and its effect on the globally topology of the magnetospheric magnetic field will be reviewed. In particular, numerical results that are rapidly changing our view of magnetospheric reconnection within the magnetospheric magnetic field will be discussed.

  9. Automatic Texture Reconstruction of 3d City Model from Oblique Images

    NASA Astrophysics Data System (ADS)

    Kang, Junhua; Deng, Fei; Li, Xinwei; Wan, Fang

    2016-06-01

    In recent years, the photorealistic 3D city models are increasingly important in various geospatial applications related to virtual city tourism, 3D GIS, urban planning, real-estate management. Besides the acquisition of high-precision 3D geometric data, texture reconstruction is also a crucial step for generating high-quality and visually realistic 3D models. However, most of the texture reconstruction approaches are probably leading to texture fragmentation and memory inefficiency. In this paper, we introduce an automatic framework of texture reconstruction to generate textures from oblique images for photorealistic visualization. Our approach include three major steps as follows: mesh parameterization, texture atlas generation and texture blending. Firstly, mesh parameterization procedure referring to mesh segmentation and mesh unfolding is performed to reduce geometric distortion in the process of mapping 2D texture to 3D model. Secondly, in the texture atlas generation step, the texture of each segmented region in texture domain is reconstructed from all visible images with exterior orientation and interior orientation parameters. Thirdly, to avoid color discontinuities at boundaries between texture regions, the final texture map is generated by blending texture maps from several corresponding images. We evaluated our texture reconstruction framework on a dataset of a city. The resulting mesh model can get textured by created texture without resampling. Experiment results show that our method can effectively mitigate the occurrence of texture fragmentation. It is demonstrated that the proposed framework is effective and useful for automatic texture reconstruction of 3D city model.

  10. Analytical and numerical investigations on the accuracy and robustness of geometric features extracted from 3D point cloud data

    NASA Astrophysics Data System (ADS)

    Dittrich, André; Weinmann, Martin; Hinz, Stefan

    2017-04-01

    In photogrammetry, remote sensing, computer vision and robotics, a topic of major interest is represented by the automatic analysis of 3D point cloud data. This task often relies on the use of geometric features amongst which particularly the ones derived from the eigenvalues of the 3D structure tensor (e.g. the three dimensionality features of linearity, planarity and sphericity) have proven to be descriptive and are therefore commonly involved for classification tasks. Although these geometric features are meanwhile considered as standard, very little attention has been paid to their accuracy and robustness. In this paper, we hence focus on the influence of discretization and noise on the most commonly used geometric features. More specifically, we investigate the accuracy and robustness of the eigenvalues of the 3D structure tensor and also of the features derived from these eigenvalues. Thereby, we provide both analytical and numerical considerations which clearly reveal that certain features are more susceptible to discretization and noise whereas others are more robust.

  11. Modeling 3D facial shape from DNA.

    PubMed

    Claes, Peter; Liberton, Denise K; Daniels, Katleen; Rosana, Kerri Matthes; Quillen, Ellen E; Pearson, Laurel N; McEvoy, Brian; Bauchet, Marc; Zaidi, Arslan A; Yao, Wei; Tang, Hua; Barsh, Gregory S; Absher, Devin M; Puts, David A; Rocha, Jorge; Beleza, Sandra; Pereira, Rinaldo W; Baynam, Gareth; Suetens, Paul; Vandermeulen, Dirk; Wagner, Jennifer K; Boster, James S; Shriver, Mark D

    2014-03-01

    Human facial diversity is substantial, complex, and largely scientifically unexplained. We used spatially dense quasi-landmarks to measure face shape in population samples with mixed West African and European ancestry from three locations (United States, Brazil, and Cape Verde). Using bootstrapped response-based imputation modeling (BRIM), we uncover the relationships between facial variation and the effects of sex, genomic ancestry, and a subset of craniofacial candidate genes. The facial effects of these variables are summarized as response-based imputed predictor (RIP) variables, which are validated using self-reported sex, genomic ancestry, and observer-based facial ratings (femininity and proportional ancestry) and judgments (sex and population group). By jointly modeling sex, genomic ancestry, and genotype, the independent effects of particular alleles on facial features can be uncovered. Results on a set of 20 genes showing significant effects on facial features provide support for this approach as a novel means to identify genes affecting normal-range facial features and for approximating the appearance of a face from genetic markers.

  12. Modeling 3D Facial Shape from DNA

    PubMed Central

    Claes, Peter; Liberton, Denise K.; Daniels, Katleen; Rosana, Kerri Matthes; Quillen, Ellen E.; Pearson, Laurel N.; McEvoy, Brian; Bauchet, Marc; Zaidi, Arslan A.; Yao, Wei; Tang, Hua; Barsh, Gregory S.; Absher, Devin M.; Puts, David A.; Rocha, Jorge; Beleza, Sandra; Pereira, Rinaldo W.; Baynam, Gareth; Suetens, Paul; Vandermeulen, Dirk; Wagner, Jennifer K.; Boster, James S.; Shriver, Mark D.

    2014-01-01

    Human facial diversity is substantial, complex, and largely scientifically unexplained. We used spatially dense quasi-landmarks to measure face shape in population samples with mixed West African and European ancestry from three locations (United States, Brazil, and Cape Verde). Using bootstrapped response-based imputation modeling (BRIM), we uncover the relationships between facial variation and the effects of sex, genomic ancestry, and a subset of craniofacial candidate genes. The facial effects of these variables are summarized as response-based imputed predictor (RIP) variables, which are validated using self-reported sex, genomic ancestry, and observer-based facial ratings (femininity and proportional ancestry) and judgments (sex and population group). By jointly modeling sex, genomic ancestry, and genotype, the independent effects of particular alleles on facial features can be uncovered. Results on a set of 20 genes showing significant effects on facial features provide support for this approach as a novel means to identify genes affecting normal-range facial features and for approximating the appearance of a face from genetic markers. PMID:24651127

  13. Modelling Polymer Deformation during 3D Printing

    NASA Astrophysics Data System (ADS)

    McIlroy, Claire; Olmsted, Peter

    Three-dimensional printing has the potential to transform manufacturing processes, yet improving the strength of printed parts, to equal that of traditionally-manufactured parts, remains an underlying issue. The fused deposition modelling technique involves melting a thermoplastic, followed by layer-by-layer extrusion to fabricate an object. The key to ensuring strength at the weld between layers is successful inter-diffusion. However, prior to welding, both the extrusion process and the cooling temperature profile can significantly deform the polymer micro-structure and, consequently, how well the polymers are able to ``re-entangle'' across the weld. In particular, polymer alignment in the flow can cause de-bonding of the layers and create defects. We have developed a simple model of the non-isothermal extrusion process to explore the effects that typical printing conditions and material rheology have on the conformation of a polymer melt. In particular, we incorporate both stretch and orientation using the Rolie-Poly constitutive equation to examine the melt structure as it flows through the nozzle, the subsequent alignment with the build plate and the resulting deformation due to the fixed nozzle height, which is typically less than the nozzle radius.

  14. Image based 3D city modeling : Comparative study

    NASA Astrophysics Data System (ADS)

    Singh, S. P.; Jain, K.; Mandla, V. R.

    2014-06-01

    3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India). This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can't do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good result. For Large city

  15. NoSQL Based 3D City Model Management System

    NASA Astrophysics Data System (ADS)

    Mao, B.; Harrie, L.; Cao, J.; Wu, Z.; Shen, J.

    2014-04-01

    To manage increasingly complicated 3D city models, a framework based on NoSQL database is proposed in this paper. The framework supports import and export of 3D city model according to international standards such as CityGML, KML/COLLADA and X3D. We also suggest and implement 3D model analysis and visualization in the framework. For city model analysis, 3D geometry data and semantic information (such as name, height, area, price and so on) are stored and processed separately. We use a Map-Reduce method to deal with the 3D geometry data since it is more complex, while the semantic analysis is mainly based on database query operation. For visualization, a multiple 3D city representation structure CityTree is implemented within the framework to support dynamic LODs based on user viewpoint. Also, the proposed framework is easily extensible and supports geoindexes to speed up the querying. Our experimental results show that the proposed 3D city management system can efficiently fulfil the analysis and visualization requirements.

  16. Modeling cell migration in 3D: Status and challenges.

    PubMed

    Rangarajan, Rajagopal; Zaman, Muhammad H

    2008-01-01

    Cell migration is a multi-scale process that integrates signaling, mechanics and biochemical reaction kinetics. Various mathematical models accurately predict cell migration on 2D surfaces, but are unable to capture the complexities of 3D migration. Additionally, quantitative 3D cell migration models have been few and far between. In this review we look and characterize various mathematical models available in literature to predict cell migration in 3D matrices and analyze their strengths and possible changes to these models that could improve their predictive capabilities.

  17. 3D PIC Modeling of Microcavity Discharge

    NASA Astrophysics Data System (ADS)

    Hopkins, Matthew; Manginell, Ronald; Moore, Christopher; Yee, Benjamin; Moorman, Matthew

    2015-09-01

    We present a number of techniques and challenges in simulating the transient behavior of a microcavity discharge. Our microcavities are typically cylindrical with diameters approximately 50 - 100 μm, heights of 50 - 200 μm, pressure near atmospheric, and operate at a few hundred volts. We employ a fully kinetic simulation methodology, the Particle-in-Cell (PIC) method, with interparticle collisions handled via methods based on direct simulation Monte Carlo (DSMC). In particular, we explicitly include kinetic electrons. Some of the challenges we encounter include variations in number densities, external circuit coupling, and time step resolution constraints. By employing dynamic particle weighting (particle weights vary over time by species and location) we can mitigate some of the challenges modeling systems with 107 variations in number densities. Smoothing mechanisms have been used to attempt to mitigate external circuit response. We perform our simulations on hundreds or thousands of processing cores to accommodate the computational work inherent in using relatively small time step sizes (e.g., 50 fs for a 100 ns calculation). In addition, particle weighting issues inherent to three-dimensional low temperature plasma systems will be mentioned. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's NNSA under Contract DE-AC04-94AL85000.

  18. Kongsfjorden-MIKE 3D model

    NASA Astrophysics Data System (ADS)

    Przyborska, Anna; Kosecki, Szymon; Jakacki, Jaromir

    2014-05-01

    Kongsfjorden is a West Svalbard fjord with a surface area of about 210 km2. It is obvious that the depths of the outer and central basins are influenced by the open sea, under influence of West Spitsbergen Current (WSC), which curry out warm Atlantic water and cold East Spitsbergen Current, while the shallower, inner basin has a large glacial outflow and its maximum depths do not exceed 100 m. Freshwater stored in Spitsbergen glaciers have strong influence on local hydrology and physical fjord conditions. Both, local and shelf conditions have impact on state of the fjord. External forces like tides, velocities at the boundary and atmospheric forces together with sources of cold and dens fresh water in the fjords will give reliable representation of physical conditions in Kongsfjorden. Modeling could help to solve this problem and we have hope that we find answer which one is the most important for local conditions in fjord. Calculations of balances between cold fresh water and warm and salt will provide additional information that could help to answer the main question of the GAME (Growing of the Arctic Marine Ecosystem) project - what is the reaction of physically controlled Arctic marine ecosystem to temperature rise.

  19. A featureless approach to 3D polyhedral building modeling from aerial images.

    PubMed

    Hammoudi, Karim; Dornaika, Fadi

    2011-01-01

    This paper presents a model-based approach for reconstructing 3D polyhedral building models from aerial images. The proposed approach exploits some geometric and photometric properties resulting from the perspective projection of planar structures. Data are provided by calibrated aerial images. The novelty of the approach lies in its featurelessness and in its use of direct optimization based on image rawbrightness. The proposed framework avoids feature extraction and matching. The 3D polyhedral model is directly estimated by optimizing an objective function that combines an image-based dissimilarity measure and a gradient score over several aerial images. The optimization process is carried out by the Differential Evolution algorithm. The proposed approach is intended to provide more accurate 3D reconstruction than feature-based approaches. Fast 3D model rectification and updating can take advantage of the proposed method. Several results and evaluations of performance from real and synthetic images show the feasibility and robustness of the proposed approach.

  20. A Featureless Approach to 3D Polyhedral Building Modeling from Aerial Images

    PubMed Central

    Hammoudi, Karim; Dornaika, Fadi

    2011-01-01

    This paper presents a model-based approach for reconstructing 3D polyhedral building models from aerial images. The proposed approach exploits some geometric and photometric properties resulting from the perspective projection of planar structures. Data are provided by calibrated aerial images. The novelty of the approach lies in its featurelessness and in its use of direct optimization based on image rawbrightness. The proposed framework avoids feature extraction and matching. The 3D polyhedral model is directly estimated by optimizing an objective function that combines an image-based dissimilarity measure and a gradient score over several aerial images. The optimization process is carried out by the Differential Evolution algorithm. The proposed approach is intended to provide more accurate 3D reconstruction than feature-based approaches. Fast 3D model rectification and updating can take advantage of the proposed method. Several results and evaluations of performance from real and synthetic images show the feasibility and robustness of the proposed approach. PMID:22346575

  1. 3D model retrieval method based on mesh segmentation

    NASA Astrophysics Data System (ADS)

    Gan, Yuanchao; Tang, Yan; Zhang, Qingchen

    2012-04-01

    In the process of feature description and extraction, current 3D model retrieval algorithms focus on the global features of 3D models but ignore the combination of global and local features of the model. For this reason, they show less effective performance to the models with similar global shape and different local shape. This paper proposes a novel algorithm for 3D model retrieval based on mesh segmentation. The key idea is to exact the structure feature and the local shape feature of 3D models, and then to compares the similarities of the two characteristics and the total similarity between the models. A system that realizes this approach was built and tested on a database of 200 objects and achieves expected results. The results show that the proposed algorithm improves the precision and the recall rate effectively.

  2. Radiometric and geometric evaluation of GeoEye-1, WorldView-2 and Pléiades-1A stereo images for 3D information extraction

    NASA Astrophysics Data System (ADS)

    Poli, D.; Remondino, F.; Angiuli, E.; Agugiaro, G.

    2015-02-01

    Today the use of spaceborne Very High Resolution (VHR) optical sensors for automatic 3D information extraction is increasing in the scientific and civil communities. The 3D Optical Metrology (3DOM) unit of the Bruno Kessler Foundation (FBK) in Trento (Italy) has collected VHR satellite imagery, as well as aerial and terrestrial data over Trento for creating a complete testfield for investigations on image radiometry, geometric accuracy, automatic digital surface model (DSM) generation, 2D/3D feature extraction, city modelling and data fusion. This paper addresses the radiometric and the geometric aspects of the VHR spaceborne imagery included in the Trento testfield and their potential for 3D information extraction. The dataset consist of two stereo-pairs acquired by WorldView-2 and by GeoEye-1 in panchromatic and multispectral mode, and a triplet from Pléiades-1A. For reference and validation, a DSM from airborne LiDAR acquisition is used. The paper gives details on the project, dataset characteristics and achieved results.

  3. Estimating 3D gaze in physical environment: a geometric approach on consumer-level remote eye tracker

    NASA Astrophysics Data System (ADS)

    Wibirama, Sunu; Mahesa, Rizki R.; Nugroho, Hanung A.; Hamamoto, Kazuhiko

    2017-02-01

    Remote eye trackers with consumer price have been used for various applications on flat computer screen. On the other hand, 3D gaze tracking in physical environment has been useful for visualizing gaze behavior, robots controller, and assistive technology. Instead of using affordable remote eye trackers, 3D gaze tracking in physical environment has been performed using corporate-level head mounted eye trackers, limiting its practical usage to niche user. In this research, we propose a novel method to estimate 3D gaze using consumer-level remote eye tracker. We implement geometric approach to obtain 3D point of gaze from binocular lines-of-sight. Experimental results show that the proposed method yielded low errors of 3.47+/-3.02 cm, 3.02+/-1.34 cm, and 2.57+/-1.85 cm in X, Y , and Z dimensions, respectively. The proposed approach may be used as a starting point for designing interaction method in 3D physical environment.

  4. Extraction of the 3D Free Space from Building Models for Indoor Navigation

    NASA Astrophysics Data System (ADS)

    Diakité, A. A.; Zlatanova, S.

    2016-10-01

    For several decades, indoor navigation has been exclusively investigated in a 2D perspective, based on floor plans, projection and other 2D representations of buildings. Nevertheless, 3D representations are closer to our reality and offer a more intuitive description of the space configuration. Thanks to recent advances in 3D modelling, 3D navigation is timidly but increasingly gaining in interest through the indoor applications. But, because the structure of indoor environment is often more complex than outdoor, very simplified models are used and obstacles are not considered for indoor navigation leading to limited possibilities in complex buildings. In this paper we consider the entire configuration of the indoor environment in 3D and introduce a method to extract from it the actual navigable space as a network of connected 3D spaces (volumes). We describe how to construct such 3D free spaces from semantically rich and furnished IFC models. The approach combines the geometric, the topological and the semantic information available in a 3D model to isolate the free space from the rest of the components. Furthermore, the extraction of such navigable spaces in building models lacking of semantic information is also considered. A data structure named combinatorial maps is used to support the operations required by the process while preserving the topological and semantic information of the input models.

  5. 3D-model building of the jaw impression

    NASA Astrophysics Data System (ADS)

    Ahmed, Moumen T.; Yamany, Sameh M.; Hemayed, Elsayed E.; Farag, Aly A.

    1997-03-01

    A novel approach is proposed to obtain a record of the patient's occlusion using computer vision. Data acquisition is obtained using intra-oral video cameras. The technique utilizes shape from shading to extract 3D information from 2D views of the jaw, and a novel technique for 3D data registration using genetic algorithms. The resulting 3D model can be used for diagnosis, treatment planning, and implant purposes. The overall purpose of this research is to develop a model-based vision system for orthodontics to replace traditional approaches. This system will be flexible, accurate, and will reduce the cost of orthodontic treatments.

  6. Formal representation of 3D structural geological models

    NASA Astrophysics Data System (ADS)

    Wang, Zhangang; Qu, Honggang; Wu, Zixing; Yang, Hongjun; Du, Qunle

    2016-05-01

    The development and widespread application of geological modeling methods has increased demands for the integration and sharing services of three dimensional (3D) geological data. However, theoretical research in the field of geological information sciences is limited despite the widespread use of Geographic Information Systems (GIS) in geology. In particular, fundamental research on the formal representations and standardized spatial descriptions of 3D structural models is required. This is necessary for accurate understanding and further applications of geological data in 3D space. In this paper, we propose a formal representation method for 3D structural models using the theory of point set topology, which produces a mathematical definition for the major types of geological objects. The spatial relationships between geologic boundaries, structures, and units are explained in detail using the 9-intersection model. Reasonable conditions for describing the topological space of 3D structural models are also provided. The results from this study can be used as potential support for the standardized representation and spatial quality evaluation of 3D structural models, as well as for specific needs related to model-based management, query, and analysis.

  7. Vehicle Surveillance with a Generic, Adaptive, 3D Vehicle Model.

    PubMed

    Leotta, Matthew J; Mundy, Joseph L

    2011-07-01

    In automated surveillance, one is often interested in tracking road vehicles, measuring their shape in 3D world space, and determining vehicle classification. To address these tasks simultaneously, an effective approach is the constrained alignment of a prior model of 3D vehicle shape to images. Previous 3D vehicle models are either generic but overly simple or rigid and overly complex. Rigid models represent exactly one vehicle design, so a large collection is needed. A single generic model can deform to a wide variety of shapes, but those shapes have been far too primitive. This paper uses a generic 3D vehicle model that deforms to match a wide variety of passenger vehicles. It is adjustable in complexity between the two extremes. The model is aligned to images by predicting and matching image intensity edges. Novel algorithms are presented for fitting models to multiple still images and simultaneous tracking while estimating shape in video. Experiments compare the proposed model to simple generic models in accuracy and reliability of 3D shape recovery from images and tracking in video. Standard techniques for classification are also used to compare the models. The proposed model outperforms the existing simple models at each task.

  8. 3D Modeling from Photos Given Topological Information.

    PubMed

    Kim, Young Min; Cho, Junghyun; Ahn, Sang Chul

    2016-09-01

    Reconstructing 3D models given a single-view 2D information is inherently an ill-posed problem and requires additional information such as shape prior or user input.We introduce a method to generate multiple 3D models of a particular category given corresponding photographs when the topological information is known. While there is a wide range of shapes for an object of a particular category, the basic topology usually remains constant.In consequence, the topological prior needs to be provided only once for each category and can be easily acquired by consulting an existing database of 3D models or by user input. The input of topological description is only connectivity information between parts; this is in contrast to previous approaches that have required users to interactively mark individual parts. Given the silhouette of an object and the topology, our system automatically finds a skeleton and generates a textured 3D model by jointly fitting multiple parts. The proposed method, therefore, opens the possibility of generating a large number of 3D models by consulting a massive number of photographs. We demonstrate examples of the topological prior and reconstructed 3D models using photos.

  9. Performance Evaluation of 3d Modeling Software for Uav Photogrammetry

    NASA Astrophysics Data System (ADS)

    Yanagi, H.; Chikatsu, H.

    2016-06-01

    UAV (Unmanned Aerial Vehicle) photogrammetry, which combines UAV and freely available internet-based 3D modeling software, is widely used as a low-cost and user-friendly photogrammetry technique in the fields such as remote sensing and geosciences. In UAV photogrammetry, only the platform used in conventional aerial photogrammetry is changed. Consequently, 3D modeling software contributes significantly to its expansion. However, the algorithms of the 3D modelling software are black box algorithms. As a result, only a few studies have been able to evaluate their accuracy using 3D coordinate check points. With this motive, Smart3DCapture and Pix4Dmapper were downloaded from the Internet and commercial software PhotoScan was also employed; investigations were performed in this paper using check points and images obtained from UAV.

  10. Automatic Texture Mapping of Architectural and Archaeological 3d Models

    NASA Astrophysics Data System (ADS)

    Kersten, T. P.; Stallmann, D.

    2012-07-01

    Today, detailed, complete and exact 3D models with photo-realistic textures are increasingly demanded for numerous applications in architecture and archaeology. Manual texture mapping of 3D models by digital photographs with software packages, such as Maxon Cinema 4D, Autodesk 3Ds Max or Maya, still requires a complex and time-consuming workflow. So, procedures for automatic texture mapping of 3D models are in demand. In this paper two automatic procedures are presented. The first procedure generates 3D surface models with textures by web services, while the second procedure textures already existing 3D models with the software tmapper. The program tmapper is based on the Multi Layer 3D image (ML3DImage) algorithm and developed in the programming language C++. The studies showing that the visibility analysis using the ML3DImage algorithm is not sufficient to obtain acceptable results of automatic texture mapping. To overcome the visibility problem the Point Cloud Painter algorithm in combination with the Z-buffer-procedure will be applied in the future.

  11. Quasi-3D Algorithm in Multi-scale Modeling Framework

    NASA Astrophysics Data System (ADS)

    Jung, J.; Arakawa, A.

    2008-12-01

    As discussed in the companion paper by Arakawa and Jung, the Quasi-3D (Q3D) Multi-scale Modeling Framework (MMF) is a 4D estimation/prediction framework that combines a GCM with a 3D anelastic vector vorticity equation model (VVM) applied to a Q3D network of horizontal grid points. This paper presents an outline of the recently revised Q3D algorithm and a highlight of the results obtained by application of the algorithm to an idealized model setting. The Q3D network of grid points consists of two sets of grid-point arrays perpendicular to each other. For a scalar variable, for example, each set consists of three parallel rows of grid points. Principal and supplementary predictions are made on the central and the two adjacent rows, respectively. The supplementary prediction is to allow the principal prediction be three-dimensional at least to the second-order accuracy. To accommodate a higher-order accuracy and to make the supplementary predictions formally three-dimensional, a few rows of ghost points are added at each side of the array. Values at these ghost points are diagnostically determined by a combination of statistical estimation and extrapolation. The basic structure of the estimation algorithm is determined in view of the global stability of Q3D advection. The algorithm is calibrated using the statistics of past data at and near the intersections of the two sets of grid- point arrays. Since the CRM in the Q3D MMF extends beyond individual GCM boxes, the CRM can be a GCM by itself. However, it is better to couple the CRM with the GCM because (1) the CRM is a Q3D CRM based on a highly anisotropic network of grid points and (2) coupling with a GCM makes it more straightforward to inherit our experience with the conventional GCMs. In the coupled system we have selected, prediction of thermdynamic variables is almost entirely done by the Q3D CRM with no direct forcing by the GCM. The coupling of the dynamics between the two components is through mutual

  12. Combined registration of 3D tibia and femur implant models in 3D magnetic resonance images

    NASA Astrophysics Data System (ADS)

    Englmeier, Karl-Hans; Siebert, Markus; von Eisenhart-Rothe, Ruediger; Graichen, Heiko

    2008-03-01

    The most frequent reasons for revision of total knee arthroplasty are loosening and abnormal axial alignment leading to an unphysiological kinematic of the knee implant. To get an idea about the postoperative kinematic of the implant, it is essential to determine the position and orientation of the tibial and femoral prosthesis. Therefore we developed a registration method for fitting 3D CAD-models of knee joint prostheses into an 3D MR image. This rigid registration is the basis for a quantitative analysis of the kinematics of knee implants. Firstly the surface data of the prostheses models are converted into a voxel representation; a recursive algorithm determines all boundary voxels of the original triangular surface data. Secondly an initial preconfiguration of the implants by the user is still necessary for the following step: The user has to perform a rough preconfiguration of both remaining prostheses models, so that the fine matching process gets a reasonable starting point. After that an automated gradient-based fine matching process determines the best absolute position and orientation: This iterative process changes all 6 parameters (3 rotational- and 3 translational parameters) of a model by a minimal amount until a maximum value of the matching function is reached. To examine the spread of the final solutions of the registration, the interobserver variability was measured in a group of testers. This variability, calculated by the relative standard deviation, improved from about 50% (pure manual registration) to 0.5% (rough manual preconfiguration and subsequent fine registration with the automatic fine matching process).

  13. Implementation of virtual models from sheet metal forming simulation into physical 3D colour models using 3D printing

    NASA Astrophysics Data System (ADS)

    Junk, S.

    2016-08-01

    Today the methods of numerical simulation of sheet metal forming offer a great diversity of possibilities for optimization in product development and in process design. However, the results from simulation are only available as virtual models. Because there are any forming tools available during the early stages of product development, physical models that could serve to represent the virtual results are therefore lacking. Physical 3D-models can be created using 3D-printing and serve as an illustration and present a better understanding of the simulation results. In this way, the results from the simulation can be made more “comprehensible” within a development team. This paper presents the possibilities of 3D-colour printing with particular consideration of the requirements regarding the implementation of sheet metal forming simulation. Using concrete examples of sheet metal forming, the manufacturing of 3D colour models will be expounded upon on the basis of simulation results.

  14. Anthropological facial approximation in three dimensions (AFA3D): computer-assisted estimation of the facial morphology using geometric morphometrics.

    PubMed

    Guyomarc'h, Pierre; Dutailly, Bruno; Charton, Jérôme; Santos, Frédéric; Desbarats, Pascal; Coqueugniot, Hélène

    2014-11-01

    This study presents Anthropological Facial Approximation in Three Dimensions (AFA3D), a new computerized method for estimating face shape based on computed tomography (CT) scans of 500 French individuals. Facial soft tissue depths are estimated based on age, sex, corpulence, and craniometrics, and projected using reference planes to obtain the global facial appearance. Position and shape of the eyes, nose, mouth, and ears are inferred from cranial landmarks through geometric morphometrics. The 100 estimated cutaneous landmarks are then used to warp a generic face to the target facial approximation. A validation by re-sampling on a subsample demonstrated an average accuracy of c. 4 mm for the overall face. The resulting approximation is an objective probable facial shape, but is also synthetic (i.e., without texture), and therefore needs to be enhanced artistically prior to its use in forensic cases. AFA3D, integrated in the TIVMI software, is available freely for further testing.

  15. 3D Bioprinting of Tissue/Organ Models.

    PubMed

    Pati, Falguni; Gantelius, Jesper; Svahn, Helene Andersson

    2016-04-04

    In vitro tissue/organ models are useful platforms that can facilitate systematic, repetitive, and quantitative investigations of drugs/chemicals. The primary objective when developing tissue/organ models is to reproduce physiologically relevant functions that typically require complex culture systems. Bioprinting offers exciting prospects for constructing 3D tissue/organ models, as it enables the reproducible, automated production of complex living tissues. Bioprinted tissues/organs may prove useful for screening novel compounds or predicting toxicity, as the spatial and chemical complexity inherent to native tissues/organs can be recreated. In this Review, we highlight the importance of developing 3D in vitro tissue/organ models by 3D bioprinting techniques, characterization of these models for evaluating their resemblance to native tissue, and their application in the prioritization of lead candidates, toxicity testing, and as disease/tumor models.

  16. 3D WHOLE-PROMINENCE FINE STRUCTURE MODELING

    SciTech Connect

    Gunár, Stanislav; Mackay, Duncan H.

    2015-04-20

    We present the first 3D whole-prominence fine structure model. The model combines a 3D magnetic field configuration of an entire prominence obtained from nonlinear force-free field simulations, with a detailed description of the prominence plasma. The plasma is located in magnetic dips in hydrostatic equilibrium and is distributed along multiple fine structures within the 3D magnetic model. Through the use of a novel radiative transfer visualization technique for the Hα line such plasma-loaded magnetic field model produces synthetic images of the modeled prominence comparable with high-resolution observations. This allows us for the first time to use a single technique to consistently study, in both emission on the limb and absorption against the solar disk, the fine structures of prominences/filaments produced by a magnetic field model.

  17. 3D web visualization of huge CityGML models

    NASA Astrophysics Data System (ADS)

    Prandi, F.; Devigili, F.; Soave, M.; Di Staso, U.; De Amicis, R.

    2015-08-01

    Nowadays, rapid technological development into acquiring geo-spatial information; joined to the capabilities to process these data in a relative short period of time, allows the generation of detailed 3D textured city models that will become an essential part of the modern city information infrastructure (Spatial Data Infrastructure) and, can be used to integrate various data from different sources for public accessible visualisation and many other applications. One of the main bottlenecks, which at the moment limit the use of these datasets to few experts, is a lack on efficient visualization systems through the web and interoperable frameworks that allow standardising the access to the city models. The work presented in this paper tries to satisfy these two requirements developing a 3D web-based visualization system based on OGC standards and effective visualization concepts. The architectural framework, based on Services Oriented Architecture (SOA) concepts, provides the 3D city data to a web client designed to support the view process in a very effective way. The first part of the work is to design a framework compliant to the 3D Portrayal Service drafted by the of the Open Geospatial Consortium (OGC) 3D standardization working group. The latter is related to the development of an effective web client able to render in an efficient way the 3D city models.

  18. The study of craniofacial growth patterns using 3D laser scanning and geometric morphometrics

    NASA Astrophysics Data System (ADS)

    Friess, Martin

    2006-02-01

    Throughout childhood, braincase and face grow at different rates and therefore exhibit variable proportions and positions relative to each other. Our understanding of the direction and magnitude of these growth patterns is crucial for many ergonomic applications and can be improved by advanced 3D morphometrics. The purpose of this study is to investigate this known growth allometry using 3D imaging techniques. The geometry of the head and face of 840 children, aged 2 to 19, was captured with a laser surface scanner and analyzed statistically. From each scan, 18 landmarks were extracted and registered using General Procrustes Analysis (GPA). GPA eliminates unwanted variation due to position, orientation and scale by applying a least-squares superimposition algorithm to individual landmark configurations. This approach provides the necessary normalization for the study of differences in size, shape, and their interaction (allometry). The results show that throughout adolescence, boys and girls follow a different growth trajectory, leading to marked differences not only in size but also in shape, most notably in relative proportions of the braincase. These differences can be observed during early childhood, but become most noticeable after the age of 13 years, when craniofacial growth in girls slows down significantly, whereas growth in boys continues for at least 3 more years.

  19. Numerical model of sonic boom in 3D kinematic turbulence

    NASA Astrophysics Data System (ADS)

    Coulouvrat, François; Luquet, David; Marchiano, Régis

    2015-10-01

    Sonic boom is one of the key issues to be considered in the development of future supersonic or hypersonic civil aircraft concepts. The classical sonic boom, typical for Concorde with an N-wave shape and a ground amplitude of the order of 100 Pa, prevents overland flight. Future concepts target carefully shaped sonic booms with low amplitude weak shocks. However, sonic boom when perceived at the ground level is influenced not only by the aircraft characteristics, but also by atmospheric propagation. In particular, the effect of atmospheric turbulence on sonic boom propagation near the ground is not well characterized. Flight tests performed as early as the 1960s demonstrated that classical sonic booms are sensitive to atmospheric turbulence. However, this sensitivity remains only partially understood. This is related to the fact that i) turbulence is a random process that requires a statistical approach, ii) standard methods used to predict sonic booms, mainly geometrical acoustics based on ray tracing, are inadequate within the turbulent planetary boundary layer. Moreover, the ray theory fails to predict the acoustical field in many areas of interest, such as caustics or shadow zones. These zones are of major interest for sonic boom acceptability (highest levels, lateral extent of zone of impact). These limitations outline the need for a numerical approach that is sufficiently efficient to perform a large number of realizations for a statistical approach, but that goes beyond the limitations of ray theory. With this in view, a 3D one-way numerical method solving a nonlinear scalar wave equation established for heterogeneous, moving and absorbing atmosphere, is used to assess the effects of a 3D kinematic turbulence on sonic boom in various configurations. First, a plane N-wave is propagated in the free field through random realizations of kinematic fluctuations. Then the case of a more realistic Atmospheric Boundary Layer (ABL) is investigated, with a mean

  20. 3D microstructure modeling of compressed fiber-based materials

    NASA Astrophysics Data System (ADS)

    Gaiselmann, Gerd; Tötzke, Christian; Manke, Ingo; Lehnert, Werner; Schmidt, Volker

    2014-07-01

    A novel parametrized model that describes the 3D microstructure of compressed fiber-based materials is introduced. It allows to virtually generate the microstructure of realistically compressed gas-diffusion layers (GDL). Given the input of a 3D microstructure of some fiber-based material, the model compresses the system of fibers in a uniaxial direction for arbitrary compression rates. The basic idea is to translate the fibers in the direction of compression according to a vector field which depends on the rate of compression and on the locations of fibers within the material. In order to apply the model to experimental 3D image data of fiber-based materials given for several compression states, an optimal vector field is estimated by simulated annealing. The model is applied to 3D image data of non-woven GDL in PEMFC gained by synchrotron tomography for different compression rates. The compression model is validated by comparing structural characteristics computed for experimentally compressed and virtually compressed microstructures, where two kinds of compression - using a flat stamp and a stamp with a flow-field profile - are applied. For both stamps types, a good agreement is found. Furthermore, the compression model is combined with a stochastic 3D microstructure model for uncompressed fiber-based materials. This allows to efficiently generate compressed fiber-based microstructures in arbitrary volumes.

  1. Shape: A 3D Modeling Tool for Astrophysics.

    PubMed

    Steffen, Wolfgang; Koning, Nicholas; Wenger, Stephan; Morisset, Christophe; Magnor, Marcus

    2011-04-01

    We present a flexible interactive 3D morpho-kinematical modeling application for astrophysics. Compared to other systems, our application reduces the restrictions on the physical assumptions, data type, and amount that is required for a reconstruction of an object's morphology. It is one of the first publicly available tools to apply interactive graphics to astrophysical modeling. The tool allows astrophysicists to provide a priori knowledge about the object by interactively defining 3D structural elements. By direct comparison of model prediction with observational data, model parameters can then be automatically optimized to fit the observation. The tool has already been successfully used in a number of astrophysical research projects.

  2. Supersymmetric chiral models: Geometrical aspects

    NASA Astrophysics Data System (ADS)

    Perelomov, A. M.

    1989-03-01

    We consider classical supersymmetric chiral models of field theory and focus our attention on the geometrical aspects of such theories. A characteristic feature of such models is that the interaction is not introduced by adding the interaction Lagrangian to the free field Lagrangian, but has a purely geometrical origin and is related to the inner curvature of the target manifold. In many aspects these models are analogous to gauge theories and, as became clear recently, they are also important for superstring theory, which nowadays is the most probable candidate for a truly unified theory of all interactions including gravitation.

  3. A spherical harmonics intensity model for 3D segmentation and 3D shape analysis of heterochromatin foci.

    PubMed

    Eck, Simon; Wörz, Stefan; Müller-Ott, Katharina; Hahn, Matthias; Biesdorf, Andreas; Schotta, Gunnar; Rippe, Karsten; Rohr, Karl

    2016-08-01

    The genome is partitioned into regions of euchromatin and heterochromatin. The organization of heterochromatin is important for the regulation of cellular processes such as chromosome segregation and gene silencing, and their misregulation is linked to cancer and other diseases. We present a model-based approach for automatic 3D segmentation and 3D shape analysis of heterochromatin foci from 3D confocal light microscopy images. Our approach employs a novel 3D intensity model based on spherical harmonics, which analytically describes the shape and intensities of the foci. The model parameters are determined by fitting the model to the image intensities using least-squares minimization. To characterize the 3D shape of the foci, we exploit the computed spherical harmonics coefficients and determine a shape descriptor. We applied our approach to 3D synthetic image data as well as real 3D static and real 3D time-lapse microscopy images, and compared the performance with that of previous approaches. It turned out that our approach yields accurate 3D segmentation results and performs better than previous approaches. We also show that our approach can be used for quantifying 3D shape differences of heterochromatin foci.

  4. 3D Printing of Biomolecular Models for Research and Pedagogy.

    PubMed

    Da Veiga Beltrame, Eduardo; Tyrwhitt-Drake, James; Roy, Ian; Shalaby, Raed; Suckale, Jakob; Pomeranz Krummel, Daniel

    2017-03-13

    The construction of physical three-dimensional (3D) models of biomolecules can uniquely contribute to the study of the structure-function relationship. 3D structures are most often perceived using the two-dimensional and exclusively visual medium of the computer screen. Converting digital 3D molecular data into real objects enables information to be perceived through an expanded range of human senses, including direct stereoscopic vision, touch, and interaction. Such tangible models facilitate new insights, enable hypothesis testing, and serve as psychological or sensory anchors for conceptual information about the functions of biomolecules. Recent advances in consumer 3D printing technology enable, for the first time, the cost-effective fabrication of high-quality and scientifically accurate models of biomolecules in a variety of molecular representations. However, the optimization of the virtual model and its printing parameters is difficult and time consuming without detailed guidance. Here, we provide a guide on the digital design and physical fabrication of biomolecule models for research and pedagogy using open source or low-cost software and low-cost 3D printers that use fused filament fabrication technology.

  5. Geometrical modelling of textile reinforcements

    NASA Technical Reports Server (NTRS)

    Pastore, Christopher M.; Birger, Alexander B.; Clyburn, Eugene

    1995-01-01

    The mechanical properties of textile composites are dictated by the arrangement of yarns contained with the material. Thus to develop a comprehensive understanding of the performance of these materials, it is necessary to develop a geometrical model of the fabric structure. This task is quite complex, as the fabric is made form highly flexible yarn systems which experience a certain degree of compressability. Furthermore there are tremendous forces acting on the fabric during densification typically resulting in yarn displacement and misorientation. The objective of this work is to develop a methodology for characterizing the geometry of yarns within a fabric structure including experimental techniques for evaluating these models. Furthermore, some applications of these geometric results to mechanical prediction models are demonstrated. Although more costly than its predecessors, the present analysis is based on the detailed architecture developed by one of the authors and his colleagues and accounts for many of the geometric complexities that other analyses ignore.

  6. Automated 3D Damaged Cavity Model Builder for Lower Surface Acreage Tile on Orbiter

    NASA Technical Reports Server (NTRS)

    Belknap, Shannon; Zhang, Michael

    2013-01-01

    The 3D Automated Thermal Tool for Damaged Acreage Tile Math Model builder was developed to perform quickly and accurately 3D thermal analyses on damaged lower surface acreage tiles and structures beneath the damaged locations on a Space Shuttle Orbiter. The 3D model builder created both TRASYS geometric math models (GMMs) and SINDA thermal math models (TMMs) to simulate an idealized damaged cavity in the damaged tile(s). The GMMs are processed in TRASYS to generate radiation conductors between the surfaces in the cavity. The radiation conductors are inserted into the TMMs, which are processed in SINDA to generate temperature histories for all of the nodes on each layer of the TMM. The invention allows a thermal analyst to create quickly and accurately a 3D model of a damaged lower surface tile on the orbiter. The 3D model builder can generate a GMM and the correspond ing TMM in one or two minutes, with the damaged cavity included in the tile material. A separate program creates a configuration file, which would take a couple of minutes to edit. This configuration file is read by the model builder program to determine the location of the damage, the correct tile type, tile thickness, structure thickness, and SIP thickness of the damage, so that the model builder program can build an accurate model at the specified location. Once the models are built, they are processed by the TRASYS and SINDA.

  7. Potential of 3D City Models to assess flood vulnerability

    NASA Astrophysics Data System (ADS)

    Schröter, Kai; Bochow, Mathias; Schüttig, Martin; Nagel, Claus; Ross, Lutz; Kreibich, Heidi

    2016-04-01

    Vulnerability, as the product of exposure and susceptibility, is a key factor of the flood risk equation. Furthermore, the estimation of flood loss is very sensitive to the choice of the vulnerability model. Still, in contrast to elaborate hazard simulations, vulnerability is often considered in a simplified manner concerning the spatial resolution and geo-location of exposed objects as well as the susceptibility of these objects at risk. Usually, area specific potential flood loss is quantified on the level of aggregated land-use classes, and both hazard intensity and resistance characteristics of affected objects are represented in highly simplified terms. We investigate the potential of 3D City Models and spatial features derived from remote sensing data to improve the differentiation of vulnerability in flood risk assessment. 3D City Models are based on CityGML, an application scheme of the Geography Markup Language (GML), which represents the 3D geometry, 3D topology, semantics and appearance of objects on different levels of detail. As such, 3D City Models offer detailed spatial information which is useful to describe the exposure and to characterize the susceptibility of residential buildings at risk. This information is further consolidated with spatial features of the building stock derived from remote sensing data. Using this database a spatially detailed flood vulnerability model is developed by means of data-mining. Empirical flood damage data are used to derive and to validate flood susceptibility models for individual objects. We present first results from a prototype application in the city of Dresden, Germany. The vulnerability modeling based on 3D City Models and remote sensing data is compared i) to the generally accepted good engineering practice based on area specific loss potential and ii) to a highly detailed representation of flood vulnerability based on a building typology using urban structure types. Comparisons are drawn in terms of

  8. 3D head model classification using optimized EGI

    NASA Astrophysics Data System (ADS)

    Tong, Xin; Wong, Hau-san; Ma, Bo

    2006-02-01

    With the general availability of 3D digitizers and scanners, 3D graphical models have been used widely in a variety of applications. This has led to the development of search engines for 3D models. Especially, 3D head model classification and retrieval have received more and more attention in view of their many potential applications in criminal identifications, computer animation, movie industry and medical industry. This paper addresses the 3D head model classification problem using 2D subspace analysis methods such as 2D principal component analysis (2D PCA[3]) and 2D fisher discriminant analysis (2DLDA[5]). It takes advantage of the fact that the histogram is a 2D image, and we can extract the most useful information from these 2D images to get a good result accordingingly. As a result, there are two main advantages: First, we can perform less calculation to obtain the same rate of classification; second, we can reduce the dimensionality more than PCA to obtain a higher efficiency.

  9. 3D MHD Models of Active Region Loops

    NASA Technical Reports Server (NTRS)

    Ofman, Leon

    2004-01-01

    Present imaging and spectroscopic observations of active region loops allow to determine many physical parameters of the coronal loops, such as the density, temperature, velocity of flows in loops, and the magnetic field. However, due to projection effects many of these parameters remain ambiguous. Three dimensional imaging in EUV by the STEREO spacecraft will help to resolve the projection ambiguities, and the observations could be used to setup 3D MHD models of active region loops to study the dynamics and stability of active regions. Here the results of 3D MHD models of active region loops are presented, and the progress towards more realistic 3D MHD models of active regions. In particular the effects of impulsive events on the excitation of active region loop oscillations, and the generation, propagations and reflection of EIT waves are shown. It is shown how 3D MHD models together with 3D EUV observations can be used as a diagnostic tool for active region loop physical parameters, and to advance the science of the sources of solar coronal activity.

  10. Retrospective correction of B0-field-induced geometric distortions in multislice echo planar images: a 3D solution

    NASA Astrophysics Data System (ADS)

    McColl, Roderick W.; Coburn, Edward A.

    2000-04-01

    A method has been developed to utilize a 3D B0 fieldmap, with a multi-volume-of-interest segmentation map, to quantify and correct geometric distortions in echo-planar images. The purpose is to provide accurate co-registration of anatomical MRI to functional MRI time course sequences. A data structure capable of extracting and reporting the necessary information forms a central part of the solution. Images were obtained from a 1.5 Tesla scanner with an experimental y-gradient insert coil. Two 3D-gradient echo sequences supply the data needed to calculate the B0 map across the volume. Segmentation of the volume into brain/background produces the data needed for the phase unwrapping and volume(s) of interest generation, from which the global B0 variation map is obtained. Subsequent EPI acquisition yields the fMRI time- course information. Tests were carried out on a phantom and a human volunteer engaged in a motor task (finger-tapping). Strong distortions were measured, and subsequently corrected, particularly near the petrous bone/mastoid air cells and in the frontal and maxillary sinuses. Additionally, a strong eddy current resulting from the unshielded y-gradient was detected. The method facilitates geometric distortion correction through an imaging volume, containing multiple regions of interest within a slice, starting from a single starting point.

  11. Geometric Electron Models.

    ERIC Educational Resources Information Center

    Nika, G. Gerald; Parameswaran, R.

    1997-01-01

    Describes a visual approach for explaining the filling of electrons in the shells, subshells, and orbitals of the chemical elements. Enables students to apply the principles of atomic electron configuration while using manipulatives to model the building up of electron configurations as the atomic numbers of elements increase on the periodic…

  12. 3D model of amphioxus steroid receptor complexed with estradiol

    SciTech Connect

    Baker, Michael E.; Chang, David J.

    2009-08-28

    The origins of signaling by vertebrate steroids are not fully understood. An important advance was the report that an estrogen-binding steroid receptor [SR] is present in amphioxus, a basal chordate with a similar body plan as vertebrates. To investigate the evolution of estrogen-binding to steroid receptors, we constructed a 3D model of amphioxus SR complexed with estradiol. This 3D model indicates that although the SR is activated by estradiol, some interactions between estradiol and human ER{alpha} are not conserved in the SR, which can explain the low affinity of estradiol for the SR. These differences between the SR and ER{alpha} in the steroid-binding domain are sufficient to suggest that another steroid is the physiological regulator of the SR. The 3D model predicts that mutation of Glu-346 to Gln will increase the affinity of testosterone for amphioxus SR and elucidate the evolution of steroid-binding to nuclear receptors.

  13. Multi-scale modelling of strongly heterogeneous 3D composite structures using spatial Voronoi tessellation

    NASA Astrophysics Data System (ADS)

    El Said, Bassam; Ivanov, Dmitry; Long, Andrew C.; Hallett, Stephen R.

    2016-03-01

    3D composite materials are characterized by complex internal yarn architectures, leading to complex deformation and failure development mechanisms. Net-shaped preforms, which are originally periodic in nature, lose their periodicity when the fabric is draped, deformed on a tool, and consolidated to create geometrically complex composite components. As a result, the internal yarn architecture, which dominates the mechanical behaviour, becomes dependent on the structural geometry. Hence, predicting the mechanical behaviour of 3D composites requires an accurate representation of the yarn architecture within structural scale models. When applied to 3D composites, conventional finite element modelling techniques are limited to either homogenised properties at the structural scale, or the unit cell scale for a more detailed material property definition. Consequently, these models fail to capture the complex phenomena occurring across multiple length scales and their effects on a 3D composite's mechanical response. Here a multi-scale modelling approach based on a 3D spatial Voronoi tessellation is proposed. The model creates an intermediate length scale suitable for homogenisation to deal with the non-periodic nature of the final material. Information is passed between the different length scales to allow for the effect of the structural geometry to be taken into account on the smaller scales. The stiffness and surface strain predictions from the proposed model have been found to be in good agreement with experimental results. The proposed modelling framework has been used to gain important insight into the behaviour of this category of materials. It has been observed that the strain and stress distributions are strongly dependent on the internal yarn architecture and consequently on the final component geometry. Even for simple coupon tests, the internal architecture and geometric effects dominate the mechanical response. Consequently, the behaviour of 3D woven

  14. Air Pollution Modeling Using A 3-d Hemispheric Nested Model

    NASA Astrophysics Data System (ADS)

    Frohn, L. M.; Christensen, J. H.; Brandt, J.; Hertel, O.

    A 3-D Eulerian transport-chemistry model based on modules and parameterisations from models developed over the last decade at the National Environmental Research Institute (DREAM, DEHM, ACDEP and DEOM) has been developed. The model is hemispheric with currently two nests implemented. The horizontal resolution in the mother domain is 150 km x 150 km. First nest covers the European area wit,h a 50 km x 50 km resolution, second covers the Scandinavian area with a resolution of 16.67 km x 16.67 km. The model employs a chemical scheme (originally 53 species) which has been modified to include a detailed description of the nitrogen chemistry. The concentration of air pollutants, such as sulfur and nitrogen in various forms, has been calculated with the model, applying no nesting as well as one and two nests. The calculated values have been validated by comparison to measurements from more than 200 EMEP monitoring stations. Furthermore deposition of nitrogen to marine waters has been estimated with the model. The goal is to obtain an improved description of spatial and temporal variations in the nutrient deposition to the marine environment. In the presentation the physics and chemistry of the model will be shortly described. Validations of the model calculations by comparison to EMEP measurements will be shown and discussed together with the results of the deposition calculations.

  15. Ontogenetic development and sexual dimorphism of franciscana dolphin skull: A 3D geometric morphometric approach.

    PubMed

    del Castillo, Daniela L; Flores, David A; Cappozzo, Humberto L

    2014-12-01

    The aim of this work was to study the postnatal ontogenetic development of Pontoporia blainvillei skull, identifying major changes on shape, and relating them to relevant factors in the life history of the species. We analyzed a complete ontogenetic series (73♂, 83♀) with three-dimensional geometric morphometric techniques. Immature dolphins showed a very well-developed braincase and a poorly developed rostrum, and the principal postnatal changes affected the rostrum and the temporal fossa, both structures implied functionally to the feeding apparatus, thus suggesting a specialized mode for catch fast prey in P. blainvillei. Osseous elements associated with sound production were already well developed on immature dolphins, suggesting the importance of this apparatus since the beginning of postnatal life. Sexual dimorphism was detected on both shape and size variables. Females were bigger than males, in accordance with previous studies. Shape differences between sexes were found on the posterior part of premaxillaries and external bony nares (P < 0.01), suggesting that this sexual dimorphism is related to differences on vocalization capabilities.

  16. Parallel Optimization of 3D Cardiac Electrophysiological Model Using GPU.

    PubMed

    Xia, Yong; Wang, Kuanquan; Zhang, Henggui

    2015-01-01

    Large-scale 3D virtual heart model simulations are highly demanding in computational resources. This imposes a big challenge to the traditional computation resources based on CPU environment, which already cannot meet the requirement of the whole computation demands or are not easily available due to expensive costs. GPU as a parallel computing environment therefore provides an alternative to solve the large-scale computational problems of whole heart modeling. In this study, using a 3D sheep atrial model as a test bed, we developed a GPU-based simulation algorithm to simulate the conduction of electrical excitation waves in the 3D atria. In the GPU algorithm, a multicellular tissue model was split into two components: one is the single cell model (ordinary differential equation) and the other is the diffusion term of the monodomain model (partial differential equation). Such a decoupling enabled realization of the GPU parallel algorithm. Furthermore, several optimization strategies were proposed based on the features of the virtual heart model, which enabled a 200-fold speedup as compared to a CPU implementation. In conclusion, an optimized GPU algorithm has been developed that provides an economic and powerful platform for 3D whole heart simulations.

  17. Parallel Optimization of 3D Cardiac Electrophysiological Model Using GPU

    PubMed Central

    Xia, Yong; Wang, Kuanquan; Zhang, Henggui

    2015-01-01

    Large-scale 3D virtual heart model simulations are highly demanding in computational resources. This imposes a big challenge to the traditional computation resources based on CPU environment, which already cannot meet the requirement of the whole computation demands or are not easily available due to expensive costs. GPU as a parallel computing environment therefore provides an alternative to solve the large-scale computational problems of whole heart modeling. In this study, using a 3D sheep atrial model as a test bed, we developed a GPU-based simulation algorithm to simulate the conduction of electrical excitation waves in the 3D atria. In the GPU algorithm, a multicellular tissue model was split into two components: one is the single cell model (ordinary differential equation) and the other is the diffusion term of the monodomain model (partial differential equation). Such a decoupling enabled realization of the GPU parallel algorithm. Furthermore, several optimization strategies were proposed based on the features of the virtual heart model, which enabled a 200-fold speedup as compared to a CPU implementation. In conclusion, an optimized GPU algorithm has been developed that provides an economic and powerful platform for 3D whole heart simulations. PMID:26581957

  18. Geospatial Modelling Approach for 3d Urban Densification Developments

    NASA Astrophysics Data System (ADS)

    Koziatek, O.; Dragićević, S.; Li, S.

    2016-06-01

    With growing populations, economic pressures, and the need for sustainable practices, many urban regions are rapidly densifying developments in the vertical built dimension with mid- and high-rise buildings. The location of these buildings can be projected based on key factors that are attractive to urban planners, developers, and potential buyers. Current research in this area includes various modelling approaches, such as cellular automata and agent-based modelling, but the results are mostly linked to raster grids as the smallest spatial units that operate in two spatial dimensions. Therefore, the objective of this research is to develop a geospatial model that operates on irregular spatial tessellations to model mid- and high-rise buildings in three spatial dimensions (3D). The proposed model is based on the integration of GIS, fuzzy multi-criteria evaluation (MCE), and 3D GIS-based procedural modelling. Part of the City of Surrey, within the Metro Vancouver Region, Canada, has been used to present the simulations of the generated 3D building objects. The proposed 3D modelling approach was developed using ESRI's CityEngine software and the Computer Generated Architecture (CGA) language.

  19. Automatic procedure for realistic 3D finite element modelling of human brain for bioelectromagnetic computations

    NASA Astrophysics Data System (ADS)

    Aristovich, K. Y.; Khan, S. H.

    2010-07-01

    Realistic computer modelling of biological objects requires building of very accurate and realistic computer models based on geometric and material data, type, and accuracy of numerical analyses. This paper presents some of the automatic tools and algorithms that were used to build accurate and realistic 3D finite element (FE) model of whole-brain. These models were used to solve the forward problem in magnetic field tomography (MFT) based on Magnetoencephalography (MEG). The forward problem involves modelling and computation of magnetic fields produced by human brain during cognitive processing. The geometric parameters of the model were obtained from accurate Magnetic Resonance Imaging (MRI) data and the material properties - from those obtained from Diffusion Tensor MRI (DTMRI). The 3D FE models of the brain built using this approach has been shown to be very accurate in terms of both geometric and material properties. The model is stored on the computer in Computer-Aided Parametrical Design (CAD) format. This allows the model to be used in a wide a range of methods of analysis, such as finite element method (FEM), Boundary Element Method (BEM), Monte-Carlo Simulations, etc. The generic model building approach presented here could be used for accurate and realistic modelling of human brain and many other biological objects.

  20. Integration of 3D photogrammetric outcrop models in the reservoir modelling workflow

    NASA Astrophysics Data System (ADS)

    Deschamps, Remy; Joseph, Philippe; Lerat, Olivier; Schmitz, Julien; Doligez, Brigitte; Jardin, Anne

    2014-05-01

    3D technologies are now widely used in geosciences to reconstruct outcrops in 3D. The technology used for the 3D reconstruction is usually based on Lidar, which provides very precise models. Such datasets offer the possibility to build well-constrained outcrop analogue models for reservoir study purposes. The photogrammetry is an alternate methodology which principles are based in determining the geometric properties of an object from photographic pictures taken from different angles. Outcrop data acquisition is easy, and this methodology allows constructing 3D outcrop models with many advantages such as: - light and fast acquisition, - moderate processing time (depending on the size of the area of interest), - integration of field data and 3D outcrops into the reservoir modelling tools. Whatever the method, the advantages of digital outcrop model are numerous as already highlighted by Hodgetts (2013), McCaffrey et al. (2005) and Pringle et al. (2006): collection of data from otherwise inaccessible areas, access to different angles of view, increase of the possible measurements, attributes analysis, fast rate of data collection, and of course training and communication. This paper proposes a workflow where 3D geocellular models are built by integrating all sources of information from outcrops (surface picking, sedimentological sections, structural and sedimentary dips…). The 3D geomodels that are reconstructed can be used at the reservoir scale, in order to compare the outcrop information with subsurface models: the detailed facies models of the outcrops are transferred into petrophysical and acoustic models, which are used to test different scenarios of seismic and fluid flow modelling. The detailed 3D models are also used to test new techniques of static reservoir modelling, based either on geostatistical approaches or on deterministic (process-based) simulation techniques. A modelling workflow has been designed to model reservoir geometries and properties from

  1. 3D Model Generation From the Engineering Drawing

    NASA Astrophysics Data System (ADS)

    Vaský, Jozef; Eliáš, Michal; Bezák, Pavol; Červeňanská, Zuzana; Izakovič, Ladislav

    2010-01-01

    The contribution deals with the transformation of engineering drawings in a paper form into a 3D computer representation. A 3D computer model can be further processed in CAD/CAM system, it can be modified, archived, and a technical drawing can be then generated from it as well. The transformation process from paper form to the data one is a complex and difficult one, particularly owing to the different types of drawings, forms of displayed objects and encountered errors and deviations from technical standards. The algorithm for 3D model generating from an orthogonal vector input representing a simplified technical drawing of the rotational part is described in this contribution. The algorithm was experimentally implemented as ObjectARX application in the AutoCAD system and the test sample as the representation of the rotational part was used for verificaton.

  2. Analysis of Hyoid-Larynx Complex Using 3D Geometric Morphometrics.

    PubMed

    Loth, Anthony; Corny, Julien; Santini, Laure; Dahan, Laurie; Dessi, Patrick; Adalian, Pascal; Fakhry, Nicolas

    2015-06-01

    The aim of this study was to obtain a quantitative anatomical description of the hyoid bone-larynx complex using modern 3D reconstruction tools. The study was conducted on 104 bones from CT scan images of living adult subjects. Three-dimensional reconstructions were created from CT scan images using AVIZO 6.2 software package. A study of this complex was carried out using metric and morphological analyses. Characteristics of the hyoid bone and larynx were highly heterogeneous and were closely linked with the sex, height, and weight of the individuals. Height and width of larynx were significantly greater in men than in women (24.99 vs. 17.3 mm, p ≤ 0.05 and 46.75 vs. 41.07, p ≤ 0.05), whereas the thyroid angle was larger in females (81.12° vs. 74.48°, p ≤ 0.05). There was a significant correlation between the height and weight of subjects and different measurements of the hyoid-larynx complex. (Pearson's coefficient correlation r = 0.42, p ≤ 0.05 between the height of thyroid ala and the height of subjects and r = 0.1, p ≤ 0.05 between the height of thyroid ala and the weight of subjects). Shape and size analysis of the hyoid-larynx complex showed the existence of a significant sexual dimorphism and high interindividual heterogeneity depending to patient morphology. These results encourage us to go further with functional and imaging correlations.

  3. Dynamic earthquake rupture simulations on nonplanar faults embedded in 3D geometrically complex, heterogeneous elastic solids

    SciTech Connect

    Duru, Kenneth; Dunham, Eric M.

    2016-01-15

    Dynamic propagation of shear ruptures on a frictional interface in an elastic solid is a useful idealization of natural earthquakes. The conditions relating discontinuities in particle velocities across fault zones and tractions acting on the fault are often expressed as nonlinear friction laws. The corresponding initial boundary value problems are both numerically and computationally challenging. In addition, seismic waves generated by earthquake ruptures must be propagated for many wavelengths away from the fault. Therefore, reliable and efficient numerical simulations require both provably stable and high order accurate numerical methods. We present a high order accurate finite difference method for: a) enforcing nonlinear friction laws, in a consistent and provably stable manner, suitable for efficient explicit time integration; b) dynamic propagation of earthquake ruptures along nonplanar faults; and c) accurate propagation of seismic waves in heterogeneous media with free surface topography. We solve the first order form of the 3D elastic wave equation on a boundary-conforming curvilinear mesh, in terms of particle velocities and stresses that are collocated in space and time, using summation-by-parts (SBP) finite difference operators in space. Boundary and interface conditions are imposed weakly using penalties. By deriving semi-discrete energy estimates analogous to the continuous energy estimates we prove numerical stability. The finite difference stencils used in this paper are sixth order accurate in the interior and third order accurate close to the boundaries. However, the method is applicable to any spatial operator with a diagonal norm satisfying the SBP property. Time stepping is performed with a 4th order accurate explicit low storage Runge–Kutta scheme, thus yielding a globally fourth order accurate method in both space and time. We show numerical simulations on band limited self-similar fractal faults revealing the complexity of rupture

  4. Space Partitioning for Privacy Enabled 3D City Models

    NASA Astrophysics Data System (ADS)

    Filippovska, Y.; Wichmann, A.; Kada, M.

    2016-10-01

    Due to recent technological progress, data capturing and processing of highly detailed (3D) data has become extensive. And despite all prospects of potential uses, data that includes personal living spaces and public buildings can also be considered as a serious intrusion into people's privacy and a threat to security. It becomes especially critical if data is visible by the general public. Thus, a compromise is needed between open access to data and privacy requirements which can be very different for each application. As privacy is a complex and versatile topic, the focus of this work particularly lies on the visualization of 3D urban data sets. For the purpose of privacy enabled visualizations of 3D city models, we propose to partition the (living) spaces into privacy regions, each featuring its own level of anonymity. Within each region, the depicted 2D and 3D geometry and imagery is anonymized with cartographic generalization techniques. The underlying spatial partitioning is realized as a 2D map generated as a straight skeleton of the open space between buildings. The resulting privacy cells are then merged according to the privacy requirements associated with each building to form larger regions, their borderlines smoothed, and transition zones established between privacy regions to have a harmonious visual appearance. It is exemplarily demonstrated how the proposed method generates privacy enabled 3D city models.

  5. 3-D world modeling for an autonomous robot

    SciTech Connect

    Goldstein, M.; Pin, F.G.; Weisbin, C.R.

    1987-08-01

    This paper presents a methodology for a concise representation of the 3-D world model for a mobile robot, using range data. The process starts with the segmentation of the scene into ''objects'' that are given a unique label, based on principles of range continuity. Then the external surface of each object is partitioned into homogeneous surface patches. Contours of surface patches in 3-D space are identified by estimating the normal and curvature associated with each pixel. The resulting surface patches are then classified as planar, convex or concave. Since the world model uses a volumetric representation for the 3-D environment, planar surfaces are represented by thin volumetric polyhedra. Spherical and cylindrical surfaces are extracted and represented by appropriate volumetric primitives. All other surfaces are represented using the boolean union of spherical volumes (as described in a separate paper by the same authors). The result is a general, concise representation of the external 3-D world, which allows for efficient and robust 3-D object recognition. 20 refs., 14 figs.

  6. Coronal roots of solar wind streams: 3-D MHD modeling

    NASA Technical Reports Server (NTRS)

    Pisanko, Yu. V.

    1995-01-01

    Weak (discontinuous) solutions of the 3-D MHD equations look like a promising tool to model the transonic solar wind with structural elements: current sheets, coronal plumes etc. Using the observational information about various coronal emissions one can include these structural elements into the 3-D MHD solar wind model by embedding the discontinuities of given type. Such 3-D MHD structured solar wind is calculated self-consistently: variants are examined via numerical experiments. In particular, the behavior of coronal plumes in the transonic solar wind flow, is modeled. The input information for numerical modeling (for example, the magnetic field map at the very base of the solar corona) can be adjusted so that fast stream arises over the center of the coronal hole, over the coronal hole boundaries and, even, over the region with closed magnetic topology. 3-D MHD equations have the analytical solution which can serve as a model of supersonic trans-alfvenic solar wind in the (5-20) solar radii heliocentric distance interval. The transverse, nonradial total (gas + magnetic field) pressure balance in the flow is the corner-stone of this solution. The solution describes the filamentation (ray-like structure of the solar corona) and streaming (formation of high-speed streams with velocities up to 800 km/sec) as a consequence of the magnetic field spatial inhomogeneous structure and trans-alfvenic character of the flow. The magnetic field works in the model as a 'controller' for the solar wind streaming and filamentation.

  7. 3D modeling of dual-gate FinFET.

    PubMed

    Mil'shtein, Samson; Devarakonda, Lalitha; Zanchi, Brian; Palma, John

    2012-11-13

    The tendency to have better control of the flow of electrons in a channel of field-effect transistors (FETs) did lead to the design of two gates in junction field-effect transistors, field plates in a variety of metal semiconductor field-effect transistors and high electron mobility transistors, and finally a gate wrapping around three sides of a narrow fin-shaped channel in a FinFET. With the enhanced control, performance trends of all FETs are still challenged by carrier mobility dependence on the strengths of the electrical field along the channel. However, in cases when the ratio of FinFET volume to its surface dramatically decreases, one should carefully consider the surface boundary conditions of the device. Moreover, the inherent non-planar nature of a FinFET demands 3D modeling for accurate analysis of the device performance. Using the Silvaco modeling tool with quantization effects, we modeled a physical FinFET described in the work of Hisamoto et al. (IEEE Tran. Elec. Devices 47:12, 2000) in 3D. We compared it with a 2D model of the same device. We demonstrated that 3D modeling produces more accurate results. As 3D modeling results came close to experimental measurements, we made the next step of the study by designing a dual-gate FinFET biased at Vg1 >Vg2. It is shown that the dual-gate FinFET carries higher transconductance than the single-gate device.

  8. 3D shape decomposition and comparison for gallbladder modeling

    NASA Astrophysics Data System (ADS)

    Huang, Weimin; Zhou, Jiayin; Liu, Jiang; Zhang, Jing; Yang, Tao; Su, Yi; Law, Gim Han; Chui, Chee Kong; Chang, Stephen

    2011-03-01

    This paper presents an approach to gallbladder shape comparison by using 3D shape modeling and decomposition. The gallbladder models can be used for shape anomaly analysis and model comparison and selection in image guided robotic surgical training, especially for laparoscopic cholecystectomy simulation. The 3D shape of a gallbladder is first represented as a surface model, reconstructed from the contours segmented in CT data by a scheme of propagation based voxel learning and classification. To better extract the shape feature, the surface mesh is further down-sampled by a decimation filter and smoothed by a Taubin algorithm, followed by applying an advancing front algorithm to further enhance the regularity of the mesh. Multi-scale curvatures are then computed on the regularized mesh for the robust saliency landmark localization on the surface. The shape decomposition is proposed based on the saliency landmarks and the concavity, measured by the distance from the surface point to the convex hull. With a given tolerance the 3D shape can be decomposed and represented as 3D ellipsoids, which reveal the shape topology and anomaly of a gallbladder. The features based on the decomposed shape model are proposed for gallbladder shape comparison, which can be used for new model selection. We have collected 19 sets of abdominal CT scan data with gallbladders, some shown in normal shape and some in abnormal shapes. The experiments have shown that the decomposed shapes reveal important topology features.

  9. Alignment of 3D Building Models and TIR Video Sequences with Line Tracking

    NASA Astrophysics Data System (ADS)

    Iwaszczuk, D.; Stilla, U.

    2014-11-01

    Thermal infrared imagery of urban areas became interesting for urban climate investigations and thermal building inspections. Using a flying platform such as UAV or a helicopter for the acquisition and combining the thermal data with the 3D building models via texturing delivers a valuable groundwork for large-area building inspections. However, such thermal textures are useful for further analysis if they are geometrically correctly extracted. This can be achieved with a good coregistrations between the 3D building models and thermal images, which cannot be achieved by direct georeferencing. Hence, this paper presents methodology for alignment of 3D building models and oblique TIR image sequences taken from a flying platform. In a single image line correspondences between model edges and image line segments are found using accumulator approach and based on these correspondences an optimal camera pose is calculated to ensure the best match between the projected model and the image structures. Among the sequence the linear features are tracked based on visibility prediction. The results of the proposed methodology are presented using a TIR image sequence taken from helicopter in a densely built-up urban area. The novelty of this work is given by employing the uncertainty of the 3D building models and by innovative tracking strategy based on a priori knowledge from the 3D building model and the visibility checking.

  10. Enhanced visualization of angiograms using 3D models

    NASA Astrophysics Data System (ADS)

    Marovic, Branko S.; Duckwiler, Gary R.; Villablanca, Pablo; Valentino, Daniel J.

    1999-05-01

    The 3D visualization of intracranial vasculature can facilitate the planning of endovascular therapy and the evaluation of interventional result. To create 3D visualizations, volumetric datasets from x-ray computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are commonly rendered using maximum intensity projection (MIP), volume rendering, or surface rendering techniques. However, small aneurysms and mild stenoses are very difficult to detect using these methods. Furthermore, the instruments used during endovascular embolization or surgical treatment produce artifacts that typically make post-intervention CTA inapplicable, and the presence of magnetic material prohibits the use of MRA. Therefore, standard digital angiography is typically used. In order to address these problems, we developed a visualization and modeling system that displays 2D and 3D angiographic images using a simple Web-based interface. Polygonal models of vasculature were generated from CT and MR data using 3D segmentation of bones and vessels and polygonal surface extraction and simplification. A web-based 3D environment was developed for interactive examination of reconstructed surface models, creation of oblique cross- sections and maximum intensity projections, and distance measurements and annotations. This environment uses a multi- tier client/server approach employing VRML and Java. The 3D surface model and angiographic images can be aligned and displayed simultaneously to permit better perception of complex vasculature and to determine optical viewing positions and angles before starting an angiographic sessions. Polygonal surface reconstruction allows interactive display of complex spatial structures on inexpensive platforms such as personal computers as well as graphic workstations. The aneurysm assessment procedure demonstrated the utility of web-based technology for clinical visualization. The resulting system facilitated the treatment of serious vascular

  11. 3-D QSAutogrid/R: an alternative procedure to build 3-D QSAR models. Methodologies and applications.

    PubMed

    Ballante, Flavio; Ragno, Rino

    2012-06-25

    Since it first appeared in 1988 3-D QSAR has proved its potential in the field of drug design and activity prediction. Although thousands of citations now exist in 3-D QSAR, its development was rather slow with the majority of new 3-D QSAR applications just extensions of CoMFA. An alternative way to build 3-D QSAR models, based on an evolution of software, has been named 3-D QSAutogrid/R and has been developed to use only software freely available to academics. 3-D QSAutogrid/R covers all the main features of CoMFA and GRID/GOLPE with implementation by multiprobe/multiregion variable selection (MPGRS) that improves the simplification of interpretation of the 3-D QSAR map. The methodology is based on the integration of the molecular interaction fields as calculated by AutoGrid and the R statistical environment that can be easily coupled with many free graphical molecular interfaces such as UCSF-Chimera, AutoDock Tools, JMol, and others. The description of each R package is reported in detail, and, to assess its validity, 3-D QSAutogrid/R has been applied to three molecular data sets of which either CoMFA or GRID/GOLPE models were reported in order to compare the results. 3-D QSAutogrid/R has been used as the core engine to prepare more that 240 3-D QSAR models forming the very first 3-D QSAR server ( www.3d-qsar.com ) with its code freely available through R-Cran distribution.

  12. 3D city models for CAAD-supported analysis and design of urban areas

    NASA Astrophysics Data System (ADS)

    Sinning-Meister, M.; Gruen, A.; Dan, H.

    A joint research project was conducted at ETH Zurich to develop a user-friendly software environment for the representation, visual manipulation, analysis and design of urban areas. Three groups were involved in the project: (1) the 'Architecture and Planning' group defined the requirements and expectations for the system; (2) the 'Photogrammetry' group acquired and processed raster and 3D vector data to form a 3D model of the urban area; and (3) the 'CAAD' (Computer Aided Architectural Design) group embedded the data into AutoCAD and implemented database functionality. Results of the photogrammetry group are presented, including the implementation of a 'topology builder' which automatically fits roof planes to manually or semi-automatically measured roof points in order to create AutoCAD-compatible 3D building models. Digital orthoimages and derived products such as perspective views, and the geometric correction of house roofs in digital orthoimages also were generated for test sites in Switzerland.

  13. An Accuracy Assessment of Automated Photogrammetric Techniques for 3d Modeling of Complex Interiors

    NASA Astrophysics Data System (ADS)

    Georgantas, A.; Brédif, M.; Pierrot-Desseilligny, M.

    2012-07-01

    This paper presents a comparison of automatic photogrammetric techniques to terrestrial laser scanning for 3D modelling of complex interior spaces. We try to evaluate the automated photogrammetric techniques not only in terms of their geometric quality compared to laser scanning but also in terms of cost in money, acquisition and computational time. To this purpose we chose as test site a modern building's stairway. APERO/MICMAC ( ©IGN )which is an Open Source photogrammetric software was used for the production of the 3D photogrammetric point cloud which was compared to the one acquired by a Leica Scanstation 2 laser scanner. After performing various qualitative and quantitative controls we present the advantages and disadvantages of each 3D modelling method applied in a complex interior of a modern building.

  14. Functional morphology and integration of corvid skulls – a 3D geometric morphometric approach

    PubMed Central

    Kulemeyer, Christoph; Asbahr, Kolja; Gunz, Philipp; Frahnert, Sylke; Bairlein, Franz

    2009-01-01

    Background Sympatric corvid species have evolved differences in nesting, habitat choice, diet and foraging. Differences in the frequency with which corvid species use their repertoire of feeding techniques is expected to covary with bill-shape and with the frontal binocular field. Species that frequently probe are expected to have a relatively longer bill and more sidewise oriented orbits in contrast to species that frequently peck. We tested this prediction by analyzing computed tomography scans of skulls of six corvid species by means of three-dimensional geometric morphometrics. We (1) explored patterns of major variation using principal component analysis, (2) compared within and between species relationships of size and shape and (3) quantitatively compared patterns of morphological integration between bill and cranium by means of partial least squares (singular warp) analysis. Results Major shape variation occurs at the bill, in the orientation of orbits, in the position of the foramen magnum and in the angle between bill and cranium. The first principal component correlated positively with centroid-size, but within-species allometric relationships differed markedly. Major covariation between the bill and cranium lies in the difference in orbit orientation relative to bill-length and in the angle between bill and cranium. Conclusion Corvid species show pronounced differences in skull shape, which covary with foraging mode. Increasing bill-length, bill-curvature and sidewise orientation of the eyes is associated with an increase in the observed frequency in probing (vice versa in pecking). Hence, the frequency of probing, bill-length, bill-curvature and sidewise orientation of the eyes is progressively increased from jackdaw, to Eurasian jay, to black-billed magpie, to hooded crow, to rook and to common raven (when feeding on carcasses is considered as probing). Our results on the morphological integration suggest that most of the covariation between bill and

  15. Teaching the geological subsurface with 3D models

    NASA Astrophysics Data System (ADS)

    Thorpe, Steve; Ward, Emma

    2014-05-01

    3D geological models have great potential as a resource when teaching geological concepts as it allows the student to visualise and interrogate UK geology. They are especially useful when dealing with the conversion of 2D field, map and GIS outputs into three dimensional geological units, which is a common problem for many students. Today's earth science students use a variety of skills and processes during their learning experience including spatial thinking, image construction, detecting patterns, making predictions and deducing the orientation of themselves. 3D geological models can reinforce spatial thinking strategies and encourage students to think about processes and properties, in turn helping the student to recognise pre-learnt geological principles in the field and to convert what they see at the surface into a picture of what is going on at depth. The British Geological Survey (BGS) has been producing digital 3D geological models for over 10 years. The models produced are revolutionising the working practices, data standards and products of the BGS. Sharing our geoscience information with academia is highlighted throughout the BGS strategy as is instilling practical skills in future geoscience professionals, such as model building and interpretation. In 2009 a project was launched to investigate the potential of the models as a teaching resource. The study included justifying if and how the models help students to learn, how models have been used historically, and how other forms of modelling are being used today. BGS now produce 3D geological models for use by anyone teaching or learning geoscience. They incorporate educational strategies that will develop geospatial skills and alleviate potential problems that some students experience. They are contained within contemporary case studies and show standard geological concepts, structures, sedimentary rocks, cross sections and field techniques. 3D geological models of the Isle of Wight and Ingleborough

  16. 3D Geological Model for "LUSI" - a Deep Geothermal System

    NASA Astrophysics Data System (ADS)

    Sohrabi, Reza; Jansen, Gunnar; Mazzini, Adriano; Galvan, Boris; Miller, Stephen A.

    2016-04-01

    Geothermal applications require the correct simulation of flow and heat transport processes in porous media, and many of these media, like deep volcanic hydrothermal systems, host a certain degree of fracturing. This work aims to understand the heat and fluid transport within a new-born sedimentary hosted geothermal system, termed Lusi, that began erupting in 2006 in East Java, Indonesia. Our goal is to develop conceptual and numerical models capable of simulating multiphase flow within large-scale fractured reservoirs such as the Lusi region, with fractures of arbitrary size, orientation and shape. Additionally, these models can also address a number of other applications, including Enhanced Geothermal Systems (EGS), CO2 sequestration (Carbon Capture and Storage CCS), and nuclear waste isolation. Fractured systems are ubiquitous, with a wide-range of lengths and scales, making difficult the development of a general model that can easily handle this complexity. We are developing a flexible continuum approach with an efficient, accurate numerical simulator based on an appropriate 3D geological model representing the structure of the deep geothermal reservoir. Using previous studies, borehole information and seismic data obtained in the framework of the Lusi Lab project (ERC grant n°308126), we present here the first 3D geological model of Lusi. This model is calculated using implicit 3D potential field or multi-potential fields, depending on the geological context and complexity. This method is based on geological pile containing the geological history of the area and relationship between geological bodies allowing automatic computation of intersections and volume reconstruction. Based on the 3D geological model, we developed a new mesh algorithm to create hexahedral octree meshes to transfer the structural geological information for 3D numerical simulations to quantify Thermal-Hydraulic-Mechanical-Chemical (THMC) physical processes.

  17. A workflow for 3D model building in fold-thrust belts

    NASA Astrophysics Data System (ADS)

    Watkins, Hannah; Bond, Clare; Butler, Rob

    2016-04-01

    3D geological models can be used in fold-thrust belts for many purposes such as analysing geometric variation in folds, kinematic modelling to restore fold surfaces, generating strain distribution maps and predicting fracture network distribution. We present a workflow for 3D model building using outcrop bedding data, geological maps, Digital Terrain Models (DTM's), air photos and field photographs. We discuss the challenges of software limitations for 3D kinematic restoration and forward modelling in fold-thrust belt settings. We then discuss the sensitivity of model building approaches to the application of 3D geological models in fold-thrust belts for further analysis e.g. changes in along strike fold geometry, restoration using kinematic and geomechanical modelling, strain prediction and Discrete Fracture Network (DFN) modelling. To create 3D models geological maps and bedding data are digitised using Move software; digitised maps and data are then draped onto DTM's. A series of closely spaced cross section lines are selected; the orientation of these is calculated by determining the average orientation of bedding dip direction. Fault and horizon line intersections, along with bedding data from within a narrow margin of the section lines are projected onto each cross section. Field photographs and sketches are integrated into the cross sections to determine thrust angles at the surface. Horizon lines are then constructed using bedding data. Displacement profiles for thrusts are plotted to ensure thrust displacements are valid with respect to neighbouring cross section interpretations; any discrepancies are alleviated by making minor adjustments to horizon and thrust lines, while ensuring that resultant cross section geometries still adhere to bedding data and other field observations. Once the cross sections have been finalised, 3D surfaces are created using the horizon and thrust line interpretations on each cross section. The simple curvature of 3D surfaces

  18. Modeling the Properties of 3D Woven Composites

    NASA Technical Reports Server (NTRS)

    Cox, Brian N.

    1995-01-01

    An extensive study has been completed of the internal geometry, the mechanisms of failure, and the micromechanics of local failure events in graphite/epoxy composites with three dimensional (3D) woven reinforcement. This work has led to the development of models for predicting elastic constants, strength, notch sensitivity, and fatigue life. A summary is presented here.

  19. Performance and Cognitive Assessment in 3-D Modeling

    ERIC Educational Resources Information Center

    Fahrer, Nolan E.; Ernst, Jeremy V.; Branoff, Theodore J.; Clark, Aaron C.

    2011-01-01

    The purpose of this study was to investigate identifiable differences between performance and cognitive assessment scores in a 3-D modeling unit of an engineering drafting course curriculum. The study aimed to provide further investigation of the need of skill-based assessments in engineering/technical graphics courses to potentially increase…

  20. Coarse-grained modeling of RNA 3D structure.

    PubMed

    Dawson, Wayne K; Maciejczyk, Maciej; Jankowska, Elzbieta J; Bujnicki, Janusz M

    2016-07-01

    Functional RNA molecules depend on three-dimensional (3D) structures to carry out their tasks within the cell. Understanding how these molecules interact to carry out their biological roles requires a detailed knowledge of RNA 3D structure and dynamics as well as thermodynamics, which strongly governs the folding of RNA and RNA-RNA interactions as well as a host of other interactions within the cellular environment. Experimental determination of these properties is difficult, and various computational methods have been developed to model the folding of RNA 3D structures and their interactions with other molecules. However, computational methods also have their limitations, especially when the biological effects demand computation of the dynamics beyond a few hundred nanoseconds. For the researcher confronted with such challenges, a more amenable approach is to resort to coarse-grained modeling to reduce the number of data points and computational demand to a more tractable size, while sacrificing as little critical information as possible. This review presents an introduction to the topic of coarse-grained modeling of RNA 3D structures and dynamics, covering both high- and low-resolution strategies. We discuss how physics-based approaches compare with knowledge based methods that rely on databases of information. In the course of this review, we discuss important aspects in the reasoning process behind building different models and the goals and pitfalls that can result.

  1. Assessment of 3D Models Used in Contours Studies

    ERIC Educational Resources Information Center

    Alvarez, F. J. Ayala; Parra, E. B. Blazquez; Tubio, F. Montes

    2015-01-01

    This paper presents an experimental research focusing on the view of first year students. The aim is to check the quality of implementing 3D models integrated in the curriculum. We search to determine students' preference between the various means facilitated in order to understand the given subject. Students have been respondents to prove the…

  2. Tracking people and cars using 3D modeling and CCTV.

    PubMed

    Edelman, Gerda; Bijhold, Jurrien

    2010-10-10

    The aim of this study was to find a method for the reconstruction of movements of people and cars using CCTV footage and a 3D model of the environment. A procedure is proposed, in which video streams are synchronized and displayed in a 3D model, by using virtual cameras. People and cars are represented by cylinders and boxes, which are moved in the 3D model, according to their movements as shown in the video streams. The procedure was developed and tested in an experimental setup with test persons who logged their GPS coordinates as a recording of the ground truth. Results showed that it is possible to implement this procedure and to reconstruct movements of people and cars from video recordings. The procedure was also applied to a forensic case. In this work we experienced that more situational awareness was created by the 3D model, which made it easier to track people on multiple video streams. Based on all experiences from the experimental set up and the case, recommendations are formulated for use in practice.

  3. The variants of an LOD of a 3D building model and their influence on spatial analyses

    NASA Astrophysics Data System (ADS)

    Biljecki, Filip; Ledoux, Hugo; Stoter, Jantien; Vosselman, George

    2016-06-01

    The level of detail (LOD) of a 3D city model indicates the model's grade and usability. However, there exist multiple valid variants of each LOD. As a consequence, the LOD concept is inconclusive as an instruction for the acquisition of 3D city models. For instance, the top surface of an LOD1 block model may be modelled at the eaves of a building or at its ridge height. Such variants, which we term geometric references, are often overlooked and are usually not documented in the metadata. Furthermore, the influence of a particular geometric reference on the performance of a spatial analysis is not known. In response to this research gap, we investigate a variety of LOD1 and LOD2 geometric references that are commonly employed, and perform numerical experiments to investigate their relative difference when used as input for different spatial analyses. We consider three use cases (estimation of the area of the building envelope, building volume, and shadows cast by buildings), and compute the deviations in a Monte Carlo simulation. The experiments, carried out with procedurally generated models, indicate that two 3D models representing the same building at the same LOD, but modelled according to different geometric references, may yield substantially different results when used in a spatial analysis. The outcome of our experiments also suggests that the geometric reference may have a bigger influence than the LOD, since an LOD1 with a specific geometric reference may yield a more accurate result than when using LOD2 models.

  4. Image-Based Airborne LiDAR Point Cloud Encoding for 3d Building Model Retrieval

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Chen; Lin, Chao-Hung

    2016-06-01

    With the development of Web 2.0 and cyber city modeling, an increasing number of 3D models have been available on web-based model-sharing platforms with many applications such as navigation, urban planning, and virtual reality. Based on the concept of data reuse, a 3D model retrieval system is proposed to retrieve building models similar to a user-specified query. The basic idea behind this system is to reuse these existing 3D building models instead of reconstruction from point clouds. To efficiently retrieve models, the models in databases are compactly encoded by using a shape descriptor generally. However, most of the geometric descriptors in related works are applied to polygonal models. In this study, the input query of the model retrieval system is a point cloud acquired by Light Detection and Ranging (LiDAR) systems because of the efficient scene scanning and spatial information collection. Using Point clouds with sparse, noisy, and incomplete sampling as input queries is more difficult than that by using 3D models. Because that the building roof is more informative than other parts in the airborne LiDAR point cloud, an image-based approach is proposed to encode both point clouds from input queries and 3D models in databases. The main goal of data encoding is that the models in the database and input point clouds can be consistently encoded. Firstly, top-view depth images of buildings are generated to represent the geometry surface of a building roof. Secondly, geometric features are extracted from depth images based on height, edge and plane of building. Finally, descriptors can be extracted by spatial histograms and used in 3D model retrieval system. For data retrieval, the models are retrieved by matching the encoding coefficients of point clouds and building models. In experiments, a database including about 900,000 3D models collected from the Internet is used for evaluation of data retrieval. The results of the proposed method show a clear superiority

  5. Robust 3D reconstruction system for human jaw modeling

    NASA Astrophysics Data System (ADS)

    Yamany, Sameh M.; Farag, Aly A.; Tazman, David; Farman, Allan G.

    1999-03-01

    This paper presents a model-based vision system for dentistry that will replace traditional approaches used in diagnosis, treatment planning and surgical simulation. Dentistry requires accurate 3D representation of the teeth and jaws for many diagnostic and treatment purposes. For example orthodontic treatment involves the application of force systems to teeth over time to correct malocclusion. In order to evaluate tooth movement progress, the orthodontists monitors this movement by means of visual inspection, intraoral measurements, fabrication of plastic models, photographs and radiographs, a process which is both costly and time consuming. In this paper an integrate system has been developed to record the patient's occlusion using computer vision. Data is acquired with an intraoral video camera. A modified shape from shading (SFS) technique, using perspective projection and camera calibration, is used to extract accurate 3D information from a sequence of 2D images of the jaw. A new technique for 3D data registration, using a Grid Closest Point transform and genetic algorithms, is used to register the SFS output. Triangulization is then performed, and a solid 3D model is obtained via a rapid prototype machine.

  6. 3D patient-specific model of the tibia from CT for orthopedic use

    PubMed Central

    González-Carbonell, Raide A.; Ortiz-Prado, Armando; Jacobo-Armendáriz, Victor H.; Cisneros-Hidalgo, Yosbel A.; Alpízar-Aguirre, Armando

    2015-01-01

    Objectives 3D patient-specific model of the tibia is used to determine the torque needed to initialize the tibial torsion correction. Methods The finite elements method is used in the biomechanical modeling of tibia. The geometric model of the tibia is obtained from CT images. The tibia is modeled as an anisotropic material with non-homogeneous mechanical properties. Conclusions The maximum stress is located in the shaft of tibia diaphysis. With both meshes are obtained similar results of stresses and displacements. For this patient-specific model, the torque must be greater than 30 Nm to initialize the correction of tibial torsion deformity. PMID:25829755

  7. From Tls to Hbim. High Quality Semantically-Aware 3d Modeling of Complex Architecture

    NASA Astrophysics Data System (ADS)

    Quattrini, R.; Malinverni, E. S.; Clini, P.; Nespeca, R.; Orlietti, E.

    2015-02-01

    In order to improve the framework for 3D modeling, a great challenge is to obtain the suitability of Building Information Model (BIM) platform for historical architecture. A specific challenge in HBIM is to guarantee appropriateness of geometrical accuracy. The present work demonstrates the feasibility of a whole HBIM approach for complex architectural shapes, starting from TLS point clouds. A novelty of our method is to work in a 3D environment throughout the process and to develop semantics during the construction phase. This last feature of HBIM was analyzed in the present work verifying the studied ontologies, enabling the data enrichment of the model with non-geometrical information, such as historical notes, decay or deformation evidence, decorative elements etc. The case study is the Church of Santa Maria at Portonovo, an abbey from the Romanesque period. Irregular or complex historical architecture, such as Romanesque, needs the construction of shared libraries starting from the survey of its already existing elements. This is another key aspect in delivering Building Information Modeling standards. In particular, we focus on the quality assessment of the obtained model, using an open-source sw and the point cloud as reference. The proposed work shows how it is possible to develop a high quality 3D model semantic-aware, capable of connecting geometrical-historical survey with descriptive thematic databases. In this way, a centralized HBIM will serve as comprehensive dataset of information about all disciplines, particularly for restoration and conservation. Moreover, the geometric accuracy will ensure also reliable visualization outputs.

  8. 3D Geological modelling - towards a European level infrastructure

    NASA Astrophysics Data System (ADS)

    Lee, Kathryn A.; van der Krogt, Rob; Busschers, Freek S.

    2013-04-01

    The joint European Geological Surveys are preparing the ground for a "European Geological Data Infrastructure" (EGDI), under the framework of the FP7-project EGDI-Scope. This scoping study, started in June 2012, for a pan-European e-Infrastructure is based on the successes of earlier joint projects including 'OneGeology-Europe' and aims to provide the backbone for serving interoperable, geological data currently held by European Geological Surveys. Also data from past, ongoing and future European projects will be incorporated. The scope will include an investigation of the functional and technical requirements for serving 3D geological models and will look to research the potential for providing a framework to integrate models at different scales, and form a structure for enabling the development of new and innovative model delivery mechanisms. The EGDI-scope project encourages pan-European inter-disciplinary collaboration between all European Geological Surveys. It aims to enhance emerging web based technologies that will facilitate the delivery of geological data to user communities involved in European policy making and international industry, but also to geoscientific research communities and the general public. Therefore, stakeholder input and communication is imperative to the success, as is the collaboration with all the Geological Surveys of Europe. The most important functional and technical requirements for delivery of such information at pan-European level will be derived from exchanges with relevant European stakeholder representatives and providers of geological data. For handling and delivering 3D geological model data the project will need to address a number of strategic issues: • Which are the most important issues and queries for the relevant stakeholders, requiring 3D geological models? How can this be translated to functional requirements for development and design of an integrated European application? • How to handle the very large

  9. Detecting and estimating errors in 3D restoration methods using analog models.

    NASA Astrophysics Data System (ADS)

    José Ramón, Ma; Pueyo, Emilio L.; Briz, José Luis

    2015-04-01

    Some geological scenarios may be important for a number of socio-economic reasons, such as water or energy resources, but the available underground information is often limited, scarce and heterogeneous. A truly 3D reconstruction, which is still necessary during the decision-making process, may have important social and economic implications. For this reason, restoration methods were developed. By honoring some geometric or mechanical laws, they help build a reliable image of the subsurface. Pioneer methods were firstly applied in 2D (balanced and restored cross-sections) during the sixties and seventies. Later on, and due to the improvements of computational capabilities, they were extended to 3D. Currently, there are some academic and commercial restoration solutions; Unfold by the Université de Grenoble, Move by Midland Valley Exploration, Kine3D (on gOcad code) by Paradigm, Dynel3D by igeoss-Schlumberger. We have developed our own restoration method, Pmag3Drest (IGME-Universidad de Zaragoza), which is designed to tackle complex geometrical scenarios using paleomagnetic vectors as a pseudo-3D indicator of deformation. However, all these methods have limitations based on the assumptions they need to establish. For this reason, detecting and estimating uncertainty in 3D restoration methods is of key importance to trust the reconstructions. Checking the reliability and the internal consistency of every method, as well as to compare the results among restoration tools, is a critical issue never tackled so far because of the impossibility to test out the results in Nature. To overcome this problem we have developed a technique using analog models. We built complex geometric models inspired in real cases of superposed and/or conical folding at laboratory scale. The stratigraphic volumes were modeled using EVA sheets (ethylene vinyl acetate). Their rheology (tensile and tear strength, elongation, density etc) and thickness can be chosen among a large number of values

  10. Geometrical modelling of textile reinforcements

    NASA Technical Reports Server (NTRS)

    Pastore, Christopher M.; Birger, Alexander B.; Clyburn, Eugene

    1995-01-01

    The mechanical properties of textile composites are dictated by the arrangement of yarns contained within the material. Thus, to develop a comprehensive understanding of the performance of these materials, it is necessary to develop a geometrical model of the fabric structure. This task is quite complex, as the fabric is made from highly flexible yarn systems which experience a certain degree of compressibility. Furthermore there are tremendous forces acting on the fabric during densification typically resulting in yarn displacement and misorientation. The objective of this work is to develop a methodology for characterizing the geometry of yarns within a fabric structure including experimental techniques for evaluating these models. Furthermore, some applications of these geometric results to mechanical property predictions models are demonstrated.

  11. Quasi-3D Multi-scale Modeling Framework Development

    NASA Astrophysics Data System (ADS)

    Arakawa, A.; Jung, J.

    2008-12-01

    When models are truncated in or near an energetically active range of the spectrum, model physics must be changed as the resolution changes. The model physics of GCMs and that of CRMs are, however, quite different from each other and at present there is no unified formulation of model physics that automatically provides transition between these model physics. The Quasi-3D (Q3D) Multi-scale Modeling Framework (MMF) is an attempt to bridge this gap. Like the recently proposed Heterogeneous Multiscale Method (HMM) (E and Engquist 2003), MMF combines a macroscopic model, GCM, and a microscopic model, CRM. Unlike the traditional multiscale methods such as the multi-grid and adapted mesh refinement techniques, HMM and MMF are for solving multi-physics problems. They share the common objective "to design combined macroscopic-microscopic computational methods that are much more efficient than solving the full microscopic model and at the same time give the information we need" (E et al. 2008). The question is then how to meet this objective in practice, which can be highly problem dependent. In HHM, the efficiency is gained typically by localization of the microscale problem. Following the pioneering work by Grabowski and Smolarkiewicz (1999) and Grabowski (2001), MMF takes advantage of the fact that 2D CRMs are reasonably successful in simulating deep clouds. In this approach, the efficiency is gained by sacrificing the three-dimensionality of cloud-scale motion. It also "localizes" the algorithm through embedding a CRM in each GCM grid box using cyclic boundary condition. The Q3D MMF is an attempt to reduce the expense due to these constraints by partially including the cloud-scale 3D effects and extending the CRM beyond individual GCM grid boxes. As currently formulated, the Q3D MMF is a 4D estimation/prediction framework that combines a GCM with a 3D anelastic cloud-resolving vector vorticity equation model (VVM) applied to a network of horizontal grids. The network

  12. Grid cells in 3-D: Reconciling data and models.

    PubMed

    Horiuchi, Timothy K; Moss, Cynthia F

    2015-12-01

    It is well documented that place cells and grid cells in echolocating bats show properties similar to those described in rodents, and yet, continuous theta-frequency oscillations, proposed to play a central role in grid/place cell formation, are not present in bat recordings. These comparative neurophysiological data have raised many questions about the role of theta-frequency oscillations in spatial memory and navigation. Additionally, spatial navigation in three-dimensions poses new challenges for the representation of space in neural models. Inspired by the literature on space representation in the echolocating bat, we have developed a nonoscillatory model of 3-D grid cell creation that shares many of the features of existing oscillatory-interference models. We discuss the model in the context of current knowledge of 3-D space representation and highlight directions for future research.

  13. RNA and protein 3D structure modeling: similarities and differences.

    PubMed

    Rother, Kristian; Rother, Magdalena; Boniecki, Michał; Puton, Tomasz; Bujnicki, Janusz M

    2011-09-01

    In analogy to proteins, the function of RNA depends on its structure and dynamics, which are encoded in the linear sequence. While there are numerous methods for computational prediction of protein 3D structure from sequence, there have been very few such methods for RNA. This review discusses template-based and template-free approaches for macromolecular structure prediction, with special emphasis on comparison between the already tried-and-tested methods for protein structure modeling and the very recently developed "protein-like" modeling methods for RNA. We highlight analogies between many successful methods for modeling of these two types of biological macromolecules and argue that RNA 3D structure can be modeled using "protein-like" methodology. We also highlight the areas where the differences between RNA and proteins require the development of RNA-specific solutions.

  14. Knowledge and Valorization of Historical Sites Through 3d Documentation and Modeling

    NASA Astrophysics Data System (ADS)

    Farella, E.; Menna, F.; Nocerino, E.; Morabito, D.; Remondino, F.; Campi, M.

    2016-06-01

    The paper presents the first results of an interdisciplinary project related to the 3D documentation, dissemination, valorization and digital access of archeological sites. Beside the mere 3D documentation aim, the project has two goals: (i) to easily explore and share via web references and results of the interdisciplinary work, including the interpretative process and the final reconstruction of the remains; (ii) to promote and valorize archaeological areas using reality-based 3D data and Virtual Reality devices. This method has been verified on the ruins of the archeological site of Pausilypon, a maritime villa of Roman period (Naples, Italy). Using Unity3D, the virtual tour of the heritage site was integrated and enriched with the surveyed 3D data, text documents, CAAD reconstruction hypotheses, drawings, photos, etc. In this way, starting from the actual appearance of the ruins (panoramic images), passing through the 3D digital surveying models and several other historical information, the user is able to access virtual contents and reconstructed scenarios, all in a single virtual, interactive and immersive environment. These contents and scenarios allow to derive documentation and geometrical information, understand the site, perform analyses, see interpretative processes, communicate historical information and valorize the heritage location.

  15. Stereoscopic display of 3D models for design visualization

    NASA Astrophysics Data System (ADS)

    Gilson, Kevin J.

    2006-02-01

    Advances in display technology and 3D design visualization applications have made real-time stereoscopic visualization of architectural and engineering projects a reality. Parsons Brinkerhoff (PB) is a transportation consulting firm that has used digital visualization tools from their inception and has helped pioneer the application of those tools to large scale infrastructure projects. PB is one of the first Architecture/Engineering/Construction (AEC) firms to implement a CAVE- an immersive presentation environment that includes stereoscopic rear-projection capability. The firm also employs a portable stereoscopic front-projection system, and shutter-glass systems for smaller groups. PB is using commercial real-time 3D applications in combination with traditional 3D modeling programs to visualize and present large AEC projects to planners, clients and decision makers in stereo. These presentations create more immersive and spatially realistic presentations of the proposed designs. This paper will present the basic display tools and applications, and the 3D modeling techniques PB is using to produce interactive stereoscopic content. The paper will discuss several architectural and engineering design visualizations we have produced.

  16. Parallel 3-D viscoelastic finite difference seismic modelling

    NASA Astrophysics Data System (ADS)

    Bohlen, Thomas

    2002-10-01

    Computational power has advanced to a state where we can begin to perform wavefield simulations for realistic (complex) 3-D earth models at frequencies of interest to both seismologists and engineers. On serial platforms, however, 3-D calculations are still limited to small grid sizes and short seismic wave traveltimes. To make use of the efficiency of network computers a parallel 3-D viscoelastic finite difference (FD) code is implemented which allows to distribute the work on several PCs or workstations connected via standard ethernet in an in-house network. By using the portable message passing interface standard (MPI) for the communication between processors, running times can be reduced and grid sizes can be increased significantly. Furthermore, the code shows good performance on massive parallel supercomputers which makes the computation of very large grids feasible. This implementation greatly expands the applicability of the 3-D elastic/viscoelastic finite-difference modelling technique by providing an efficient, portable and practical C-program.

  17. Geometric Modelling of Octagonal Lamp Poles

    NASA Astrophysics Data System (ADS)

    Chan, T. O.; Lichti, D. D.

    2014-06-01

    Lamp poles are one of the most abundant highway and community components in modern cities. Their supporting parts are primarily tapered octagonal cones specifically designed for wind resistance. The geometry and the positions of the lamp poles are important information for various applications. For example, they are important to monitoring deformation of aged lamp poles, maintaining an efficient highway GIS system, and also facilitating possible feature-based calibration of mobile LiDAR systems. In this paper, we present a novel geometric model for octagonal lamp poles. The model consists of seven parameters in which a rotation about the z-axis is included, and points are constrained by the trigonometric property of 2D octagons after applying the rotations. For the geometric fitting of the lamp pole point cloud captured by a terrestrial LiDAR, accurate initial parameter values are essential. They can be estimated by first fitting the points to a circular cone model and this is followed by some basic point cloud processing techniques. The model was verified by fitting both simulated and real data. The real data includes several lamp pole point clouds captured by: (1) Faro Focus 3D and (2) Velodyne HDL-32E. The fitting results using the proposed model are promising, and up to 2.9 mm improvement in fitting accuracy was realized for the real lamp pole point clouds compared to using the conventional circular cone model. The overall result suggests that the proposed model is appropriate and rigorous.

  18. 3-D HYDRODYNAMIC MODELING IN A GEOSPATIAL FRAMEWORK

    SciTech Connect

    Bollinger, J; Alfred Garrett, A; Larry Koffman, L; David Hayes, D

    2006-08-24

    3-D hydrodynamic models are used by the Savannah River National Laboratory (SRNL) to simulate the transport of thermal and radionuclide discharges in coastal estuary systems. Development of such models requires accurate bathymetry, coastline, and boundary condition data in conjunction with the ability to rapidly discretize model domains and interpolate the required geospatial data onto the domain. To facilitate rapid and accurate hydrodynamic model development, SRNL has developed a pre- and post-processor application in a geospatial framework to automate the creation of models using existing data. This automated capability allows development of very detailed models to maximize exploitation of available surface water radionuclide sample data and thermal imagery.

  19. Modeling of 3D Woven Composites Containing Multiple Delaminations

    DTIC Science & Technology

    2012-08-20

    researchers 3D woven composites shows better damage tolerance than laminated textile composites without z-yarns such as plain woven composites even...modeling of quasi-static short beam shear test of plain woven laminated composites. Cohesive elements were used in regions where transverse cracks and...Title ABSTRACT In this paper we present FE modeling of quasi-static short beam shear test of plain woven laminated composites. Cohesive elements were

  20. A method for building 3D models of barchan dunes

    NASA Astrophysics Data System (ADS)

    Nai, Yang; Li-lan, Su; Lin, Wan; Jie, Yang; Shi-yi, Chen; Wei-lu, Hu

    2016-01-01

    The distributions of barchan dunes are usually represented by digital terrain models (DTMs) overlaid with digital orthophoto maps. Given that most regions with barchan dues have low relief, a 3D map obtained from a DTM may ineffectively show the stereoscopic shape of each dune. The method of building 3D models of barchan dunes using existing modeling software seldom considers the geographical environment. As a result, barchan dune models are often inconsistent with actual DTMs and incompletely express the morphological characteristics of dunes. Manual construction of barchan dune models is also costly and time consuming. Considering these problems, the morphological characteristics of barchan dunes and the mathematical relationships between the morphological parameters of the dunes, such as length, height, and width, are analyzed in this study. The methods of extracting the morphological feature points of barchan dunes, calculating their morphological parameters and building dune outlines and skeleton lines based on the medial axes, are also presented. The dune outlines, skeleton lines, and part of the medial axes of dunes are used to construct a constrained triangulated irregular network. C# and ArcEngine are employed to build 3D models of barchan dunes automatically. Experimental results of a study conducted in Tengger Desert show that the method can be used to approximate the morphological characteristics of barchan dunes and is less time consuming than manual methods.

  1. Towards a 3d Spatial Urban Energy Modelling Approach

    NASA Astrophysics Data System (ADS)

    Bahu, J.-M.; Koch, A.; Kremers, E.; Murshed, S. M.

    2013-09-01

    Today's needs to reduce the environmental impact of energy use impose dramatic changes for energy infrastructure and existing demand patterns (e.g. buildings) corresponding to their specific context. In addition, future energy systems are expected to integrate a considerable share of fluctuating power sources and equally a high share of distributed generation of electricity. Energy system models capable of describing such future systems and allowing the simulation of the impact of these developments thus require a spatial representation in order to reflect the local context and the boundary conditions. This paper describes two recent research approaches developed at EIFER in the fields of (a) geo-localised simulation of heat energy demand in cities based on 3D morphological data and (b) spatially explicit Agent-Based Models (ABM) for the simulation of smart grids. 3D city models were used to assess solar potential and heat energy demand of residential buildings which enable cities to target the building refurbishment potentials. Distributed energy systems require innovative modelling techniques where individual components are represented and can interact. With this approach, several smart grid demonstrators were simulated, where heterogeneous models are spatially represented. Coupling 3D geodata with energy system ABMs holds different advantages for both approaches. On one hand, energy system models can be enhanced with high resolution data from 3D city models and their semantic relations. Furthermore, they allow for spatial analysis and visualisation of the results, with emphasis on spatially and structurally correlations among the different layers (e.g. infrastructure, buildings, administrative zones) to provide an integrated approach. On the other hand, 3D models can benefit from more detailed system description of energy infrastructure, representing dynamic phenomena and high resolution models for energy use at component level. The proposed modelling strategies

  2. 3-D model-based tracking for UAV indoor localization.

    PubMed

    Teulière, Céline; Marchand, Eric; Eck, Laurent

    2015-05-01

    This paper proposes a novel model-based tracking approach for 3-D localization. One main difficulty of standard model-based approach lies in the presence of low-level ambiguities between different edges. In this paper, given a 3-D model of the edges of the environment, we derive a multiple hypotheses tracker which retrieves the potential poses of the camera from the observations in the image. We also show how these candidate poses can be integrated into a particle filtering framework to guide the particle set toward the peaks of the distribution. Motivated by the UAV indoor localization problem where GPS signal is not available, we validate the algorithm on real image sequences from UAV flights.

  3. Parallel tempering and 3D spin glass models

    NASA Astrophysics Data System (ADS)

    Papakonstantinou, T.; Malakis, A.

    2014-03-01

    We review parallel tempering schemes and examine their main ingredients for accuracy and efficiency. We discuss two selection methods of temperatures and some alternatives for the exchange of replicas, including all-pair exchange methods. We measure specific heat errors and round-trip efficiency using the two-dimensional (2D) Ising model, and also test the efficiency for the ground state production in 3D spin glass models. We find that the optimization of the GS problem is highly influenced by the choice of the temperature range of the PT process. Finally, we present numerical evidence concerning the universality aspects of an anisotropic case of the 3D spin-glass model.

  4. Progressive Transmission of 3D Building Models based on String Grammars and Planar Half-Spaces

    NASA Astrophysics Data System (ADS)

    Kada, M.

    2014-11-01

    As there are numerous applications for 3D city models with a wide range of model requirements regarding geometric accuracy and granularity, there is also a high demand for such models at different levels of detail (LOD). And although their reconstruction and cartographic generalization has been widely studied, particularly with regard to 3D building models, their encoding for a progressive storage and transmission is up to now not profoundly explored and sufficiently solved. Most often building models at different LODs are considered as discrete entities that are not related to each other. In this paper we present a progressive encoding and transmission scheme for 3D building models that is easy to understand and implement for the end user as well as flexible and extensible for the model producer. The progressive scheme is based on string grammars and describes a sequence of successive LODs as a dynamic set of production rules. In order to restrict the effects of LOD changes on a local range of the progressive string representation, we use a solid modelling approach based on planar half-spaces to construct 3D buildings. The generation of such progressive string grammars is shown and examples are given.

  5. 3D Multispectral Light Propagation Model For Subcutaneous Veins Imaging

    SciTech Connect

    Paquit, Vincent C; Price, Jeffery R; Meriaudeau, Fabrice; Tobin Jr, Kenneth William

    2008-01-01

    In this paper, we describe a new 3D light propagation model aimed at understanding the effects of various physiological properties on subcutaneous vein imaging. In particular, we build upon the well known MCML (Monte Carlo Multi Layer) code and present a tissue model that improves upon the current state-of-the-art by: incorporating physiological variation, such as melanin concentration, fat content, and layer thickness; including veins of varying depth and diameter; using curved surfaces from real arm shapes; and modeling the vessel wall interface. We describe our model, present results from the Monte Carlo modeling, and compare these results with those obtained with other Monte Carlo methods.

  6. Generation and use of human 3D-CAD models

    NASA Astrophysics Data System (ADS)

    Grotepass, Juergen; Speyer, Hartmut; Kaiser, Ralf

    2002-05-01

    Individualized Products are one of the ten mega trends of the 21st Century with human modeling as the key issue for tomorrow's design and product development. The use of human modeling software for computer based ergonomic simulations within the production process increases quality while reducing costs by 30- 50 percent and shortening production time. This presentation focuses on the use of human 3D-CAD models for both, the ergonomic design of working environments and made to measure garment production. Today, the entire production chain can be designed, individualized models generated and analyzed in 3D computer environments. Anthropometric design for ergonomics is matched to human needs, thus preserving health. Ergonomic simulation includes topics as human vision, reachability, kinematics, force and comfort analysis and international design capabilities. In German more than 17 billions of Mark are moved to other industries, because clothes do not fit. Individual clothing tailored to the customer's preference means surplus value, pleasure and perfect fit. The body scanning technology is the key to generation and use of human 3D-CAD models for both, the ergonomic design of working environments and made to measure garment production.

  7. Method for modeling post-mortem biometric 3D fingerprints

    NASA Astrophysics Data System (ADS)

    Rajeev, Srijith; Shreyas, Kamath K. M.; Agaian, Sos S.

    2016-05-01

    Despite the advancements of fingerprint recognition in 2-D and 3-D domain, authenticating deformed/post-mortem fingerprints continue to be an important challenge. Prior cleansing and reconditioning of the deceased finger is required before acquisition of the fingerprint. The victim's finger needs to be precisely and carefully operated by a medium to record the fingerprint impression. This process may damage the structure of the finger, which subsequently leads to higher false rejection rates. This paper proposes a non-invasive method to perform 3-D deformed/post-mortem finger modeling, which produces a 2-D rolled equivalent fingerprint for automated verification. The presented novel modeling method involves masking, filtering, and unrolling. Computer simulations were conducted on finger models with different depth variations obtained from Flashscan3D LLC. Results illustrate that the modeling scheme provides a viable 2-D fingerprint of deformed models for automated verification. The quality and adaptability of the obtained unrolled 2-D fingerprints were analyzed using NIST fingerprint software. Eventually, the presented method could be extended to other biometric traits such as palm, foot, tongue etc. for security and administrative applications.

  8. 3D cartographic modeling of the Alpine arc

    NASA Astrophysics Data System (ADS)

    Vouillamoz, Naomi; Sue, Christian; Champagnac, Jean-Daniel; Calcagno, Philippe

    2012-12-01

    We built a 3D cartography of the Alpine arc, a highly non-cylindrical mountain belt, using the 3D GeoModeller of the BRGM (French geological survey). The model allows to handle the large-scale 3D structure of seventeen major crustal units of the belt (from the lower crust to the sedimentary cover nappes), and two main discontinuities (the Insubric Line and the Crustal Penninic Front). It provides a unique document to better understand their structural relationships and to produce new sections. The study area comprises the western Alpine arc, from the Jura to the Northwest, up to the Bergell granite intrusion and the Lepontine Dome to the East, and is limited to the South by the Ligurian basin. The model is limited vertically 10 km above sea level at the top, and the moho interface at the bottom. We discarded the structural relationships between the Alps sensus stricto and the surrounding geodynamic systems such as the Rhine graben or the connection with the Apennines. The 3D-model is based on the global integration of various data such as the DEM of the Alps, the moho isobaths, the simplified geological and tectonic maps of the belt, the crustal cross-sections ECORS-CROP and NFP-20, and complementary cross-sections specifically built to precise local complexities. The database has first been integrated in a GIS-project to prepare their implementation in the GeoModeller, by homogenizing the different spatial referencing systems. The global model is finally interpolated from all these data, using the potential field method. The final document is a new tri-dimensional cartography that would be used as input for further alpine studies.

  9. Lattice percolation approach to 3D modeling of tissue aging

    NASA Astrophysics Data System (ADS)

    Gorshkov, Vyacheslav; Privman, Vladimir; Libert, Sergiy

    2016-11-01

    We describe a 3D percolation-type approach to modeling of the processes of aging and certain other properties of tissues analyzed as systems consisting of interacting cells. Lattice sites are designated as regular (healthy) cells, senescent cells, or vacancies left by dead (apoptotic) cells. The system is then studied dynamically with the ongoing processes including regular cell dividing to fill vacant sites, healthy cells becoming senescent or dying, and senescent cells dying. Statistical-mechanics description can provide patterns of time dependence and snapshots of morphological system properties. The developed theoretical modeling approach is found not only to corroborate recent experimental findings that inhibition of senescence can lead to extended lifespan, but also to confirm that, unlike 2D, in 3D senescent cells can contribute to tissue's connectivity/mechanical stability. The latter effect occurs by senescent cells forming the second infinite cluster in the regime when the regular (healthy) cell's infinite cluster still exists.

  10. The 3D model control of image processing

    NASA Technical Reports Server (NTRS)

    Nguyen, An H.; Stark, Lawrence

    1989-01-01

    Telerobotics studies remote control of distant robots by a human operator using supervisory or direct control. Even if the robot manipulators has vision or other senses, problems arise involving control, communications, and delay. The communication delays that may be expected with telerobots working in space stations while being controlled from an Earth lab have led to a number of experiments attempting to circumvent the problem. This delay in communication is a main motivating factor in moving from well understood instantaneous hands-on manual control to less well understood supervisory control; the ultimate step would be the realization of a fully autonomous robot. The 3-D model control plays a crucial role in resolving many conflicting image processing problems that are inherent in resolving in the bottom-up approach of most current machine vision processes. The 3-D model control approach is also capable of providing the necessary visual feedback information for both the control algorithms and for the human operator.

  11. Modeling 3D faces from samplings via compressive sensing

    NASA Astrophysics Data System (ADS)

    Sun, Qi; Tang, Yanlong; Hu, Ping

    2013-07-01

    3D data is easier to acquire for family entertainment purpose today because of the mass-production, cheapness and portability of domestic RGBD sensors, e.g., Microsoft Kinect. However, the accuracy of facial modeling is affected by the roughness and instability of the raw input data from such sensors. To overcome this problem, we introduce compressive sensing (CS) method to build a novel 3D super-resolution scheme to reconstruct high-resolution facial models from rough samples captured by Kinect. Unlike the simple frame fusion super-resolution method, this approach aims to acquire compressed samples for storage before a high-resolution image is produced. In this scheme, depth frames are firstly captured and then each of them is measured into compressed samples using sparse coding. Next, the samples are fused to produce an optimal one and finally a high-resolution image is recovered from the fused sample. This framework is able to recover 3D facial model of a given user from compressed simples and this can reducing storage space as well as measurement cost in future devices e.g., single-pixel depth cameras. Hence, this work can potentially be applied into future applications, such as access control system using face recognition, and smart phones with depth cameras, which need high resolution and little measure time.

  12. 3D modelling of the Black Sea ecosystem

    NASA Astrophysics Data System (ADS)

    Capet, A.; Gregoire, M.; Beckers, J.-M.; Joassin, P.; Naithani, J.; Soetart, K.

    2009-04-01

    A coupled physical-biogeochemical model has been developed to simulate the ecosystem of the Black Sea at the end of the 80's when eutrophication and invasion by gelatinous organisms seriously affected the stability and dynamics of the system. The biogeochemical model describes the cycle of carbon, nitrogen, silicate, oxygen and phosphorus through the foodweb from bacteria to gelatinous carnivores and explicitly represents processes in the anoxic layer down to the bottom. For calibration and analyses purposes, the coupled model has first been run in 1D at several places in the Black Sea. The biogeochemical model involves some hundred parameters which have been first calibrated by hand using published values. Then, an identifiability analysis has been performed in order to determine a subset of 15 identifiable parameters. An automatic calibration subroutine has been used to fine tune these parameters. In 1D, the model solution exhibits a complex dynamics with several years of transient adjustment. This complexity is imparted by the explicit modelling of top predators. The model has been calibrated and validated using a large set of data available in the Black Sea TU Ocean Base. The calibrated biogeochemical model is implemented in a 3D hydrodynamical model of the Black Sea. Results of these 3D simulations will be presented and compared with maps of in-situ data reconstructed from available data base using the software DIVA (Data Interpolation and Variational analysis).

  13. West Flank Coso, CA FORGE 3D geologic model

    SciTech Connect

    Doug Blankenship

    2016-03-01

    This is an x,y,z file of the West Flank FORGE 3D geologic model. Model created in Earthvision by Dynamic Graphic Inc. The model was constructed with a grid spacing of 100 m. Geologic surfaces were extrapolated from the input data using a minimum tension gridding algorithm. The data file is tabular data in a text file, with lithology data associated with X,Y,Z grid points. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.

  14. 3D-printer visualization of neuron models.

    PubMed

    McDougal, Robert A; Shepherd, Gordon M

    2015-01-01

    Neurons come in a wide variety of shapes and sizes. In a quest to understand this neuronal diversity, researchers have three-dimensionally traced tens of thousands of neurons; many of these tracings are freely available through online repositories like NeuroMorpho.Org and ModelDB. Tracings can be visualized on the computer screen, used for statistical analysis of the properties of different cell types, used to simulate neuronal behavior, and more. We introduce the use of 3D printing as a technique for visualizing traced morphologies. Our method for generating printable versions of a cell or group of cells is to expand dendrite and axon diameters and then to transform the tracing into a 3D object with a neuronal surface generating algorithm like Constructive Tessellated Neuronal Geometry (CTNG). We show that 3D printed cells can be readily examined, manipulated, and compared with other neurons to gain insight into both the biology and the reconstruction process. We share our printable models in a new database, 3DModelDB, and encourage others to do the same with cells that they generate using our code or other methods. To provide additional context, 3DModelDB provides a simulatable version of each cell, links to papers that use or describe it, and links to associated entries in other databases.

  15. 3D-printer visualization of neuron models

    PubMed Central

    McDougal, Robert A.; Shepherd, Gordon M.

    2015-01-01

    Neurons come in a wide variety of shapes and sizes. In a quest to understand this neuronal diversity, researchers have three-dimensionally traced tens of thousands of neurons; many of these tracings are freely available through online repositories like NeuroMorpho.Org and ModelDB. Tracings can be visualized on the computer screen, used for statistical analysis of the properties of different cell types, used to simulate neuronal behavior, and more. We introduce the use of 3D printing as a technique for visualizing traced morphologies. Our method for generating printable versions of a cell or group of cells is to expand dendrite and axon diameters and then to transform the tracing into a 3D object with a neuronal surface generating algorithm like Constructive Tessellated Neuronal Geometry (CTNG). We show that 3D printed cells can be readily examined, manipulated, and compared with other neurons to gain insight into both the biology and the reconstruction process. We share our printable models in a new database, 3DModelDB, and encourage others to do the same with cells that they generate using our code or other methods. To provide additional context, 3DModelDB provides a simulatable version of each cell, links to papers that use or describe it, and links to associated entries in other databases. PMID:26175684

  16. Northern California Seismic Attenuation: 3-D Qp and Qs models

    NASA Astrophysics Data System (ADS)

    Eberhart-Phillips, D. M.

    2015-12-01

    The northern California crust exhibits a wide range of rock types and deformation processes which produce pronounced heterogeneity in regional attenuation. Using local earthquakes, 3-D Qp and Qs crustal models have been obtained for this region which includes the San Andreas fault system, the Central Valley, the Sierra Nevada batholith, and the Mendocino subduction volcanic system. Path attenuation t* values were determined from P and S spectra of 959 spatially distributed earthquakes, magnitude 2.5-6.0 from 2005-2014, using 1254 stations from NCEDC networks and IRIS Mendocino and Sierra Nevada temporary arrays. The t* data were used in Q inversions, using existing hypocenters and 3-D velocity models, with basic 10-km node spacing. The uneven data coverage was accounted for with linking of nodes into larger areas in order to provide useful Q images across the 3-D volume. The results at shallow depth (< 2 km) show very low Q in the Sacramento Delta, the Eureka area, and parts of the Bay Area. In the brittle crust, fault zones that have high seismicity exhibit low Q. In the lower crust, low Q is observed along fault zones that have large cumulative displacement and have experienced grain size reduction. Underlying active volcanic areas, low Q features are apparent below 20-km depth. Moderately high Q is associated with igneous rocks of the Sierra Nevada and Salinian block, while the Franciscan subduction complex shows moderately low Q. The most prominent high Q feature is related to the Great Valley Ophiolite.

  17. Right approach to 3D modeling using CAD tools

    NASA Astrophysics Data System (ADS)

    Baddam, Mounica Reddy

    The thesis provides a step-by-step methodology to enable an instructor dealing with CAD tools to optimally guide his/her students through an understandable 3D modeling approach which will not only enhance their knowledge about the tool's usage but also enable them to achieve their desired result in comparatively lesser time. In the known practical field, there is particularly very little information available to apply CAD skills to formal beginners' training sessions. Additionally, advent of new software in 3D domain cumulates updating into a more difficult task. Keeping up to the industry's advanced requirements emphasizes the importance of more skilled hands in the field of CAD development, rather than just prioritizing manufacturing in terms of complex software features. The thesis analyses different 3D modeling approaches specified to the varieties of CAD tools currently available in the market. Utilizing performance-time databases, learning curves have been generated to measure their performance time, feature count etc. Based on the results, improvement parameters have also been provided for (Asperl, 2005).

  18. Effective 3-D surface modeling for geographic information systems

    NASA Astrophysics Data System (ADS)

    Yüksek, K.; Alparslan, M.; Mendi, E.

    2016-01-01

    In this work, we propose a dynamic, flexible and interactive urban digital terrain platform with spatial data and query processing capabilities of geographic information systems, multimedia database functionality and graphical modeling infrastructure. A new data element, called Geo-Node, which stores image, spatial data and 3-D CAD objects is developed using an efficient data structure. The system effectively handles data transfer of Geo-Nodes between main memory and secondary storage with an optimized directional replacement policy (DRP) based buffer management scheme. Polyhedron structures are used in digital surface modeling and smoothing process is performed by interpolation. The experimental results show that our framework achieves high performance and works effectively with urban scenes independent from the amount of spatial data and image size. The proposed platform may contribute to the development of various applications such as Web GIS systems based on 3-D graphics standards (e.g., X3-D and VRML) and services which integrate multi-dimensional spatial information and satellite/aerial imagery.

  19. N-tuple topological/geometric cutoffs for 3D N-linear algebraic molecular codifications: variability, linear independence and QSAR analysis.

    PubMed

    García-Jacas, C R; Marrero-Ponce, Y; Barigye, S J; Hernández-Ortega, T; Cabrera-Leyva, L; Fernández-Castillo, A

    2016-12-01

    Novel N-tuple topological/geometric cutoffs to consider specific inter-atomic relations in the QuBiLS-MIDAS framework are introduced in this manuscript. These molecular cutoffs permit the taking into account of relations between more than two atoms by using (dis-)similarity multi-metrics and the concepts related with topological and Euclidean-geometric distances. To this end, the kth two-, three- and four-tuple topological and geometric neighbourhood quotient (NQ) total (or local-fragment) spatial-(dis)similarity matrices are defined, to represent 3D information corresponding to the relations between two, three and four atoms of the molecular structures that satisfy certain cutoff criteria. First, an analysis of a diverse chemical space for the most common values of topological/Euclidean-geometric distances, bond/dihedral angles, triangle/quadrilateral perimeters, triangle area and volume was performed in order to determine the intervals to take into account in the cutoff procedures. A variability analysis based on Shannon's entropy reveals that better distribution patterns are attained with the descriptors based on the cutoffs proposed (QuBiLS-MIDAS NQ-MDs) with regard to the results obtained when all inter-atomic relations are considered (QuBiLS-MIDAS KA-MDs - 'Keep All'). A principal component analysis shows that the novel molecular cutoffs codify chemical information captured by the respective QuBiLS-MIDAS KA-MDs, as well as information not captured by the latter. Lastly, a QSAR study to obtain deeper knowledge of the contribution of the proposed methods was carried out, using four molecular datasets (steroids (STER), angiotensin converting enzyme (ACE), thermolysin inhibitors (THER) and thrombin inhibitors (THR)) widely used as benchmarks in the evaluation of several methodologies. One to four variable QSAR models based on multiple linear regression were developed for each compound dataset following the original division into training and test sets. The

  20. Modeling and Processing of Continuous 3D Elastic Wavefield Data

    NASA Astrophysics Data System (ADS)

    Milkereit, B.; Bohlen, T.

    2001-12-01

    Continuous seismic wavefields are excited by earthquake clustering, induced seismicity in reservoirs, and mining. In hydrocarbon reservoirs, for example, pore pressure changes and fluid flow (mass transfer) will cause incremental deviatoric stresses sufficient to trigger and sustain seismic activity. Here we address three aspects of seismic wavefields in three-dimensional heterogeneous media triggered by distributed sources in space and time: forward modeling, multichannel data processing, and source location imaging. A power law distribution of seismic sources (such as the Gutenberg-Richter law) is used for the modeling of viscoelastic/elastic wave propagation through a realistic earth model. 3D modeling provides new insight in the interaction of multi-source wavefields and the role of scale-dependend elastic model parameters on transmitted and reflected/back-scattered wavefields. There exists a strong correlation between the spatial properties of the compressional, shear wave and density perturbations and the lateral correlation length of the resulting reflected or transmitted seismic wavefields. Modeling is based on the implementation of 3D elastic/viscoelastic FD codes on massive parallel and/or distributed computing resources using MPI (message passing interface). For parallelization, large grid 3D earth models are decomposed into subvolume processing elements whereby each processing element is updating the wavefield within its portion of the grid. Processing of continuous seismic wavefields excited by multiple distributed sources is based on a combination of crosscorrelated or slowness-transformed array data and Kirchhoff or reverse time migration for source location or source volume imaging. The appearance of slowness in both migration and array data processing suggests the possibility of combining them into a single process. In order to place further constraints on the migration, the directivity properties of 3-component receiver arrays can be included in

  1. 3D Geologic Model of the San Diego Area

    NASA Astrophysics Data System (ADS)

    Danskin, W. R.; Cromwell, G.; Glockhoff, C.; Martin, D.

    2015-12-01

    Prior geologic studies of the San Diego area, including northern Baja California, Mexico, focused on site investigations, characterization of rock formations, or earthquake hazards. No comprehensive, quantitative model characterizing the three-dimensional (3D) geology of the entire area has been developed. The lack of such a model limits understanding of large-scale processes, such as development of ancient landforms, and groundwater movement and availability. To evaluate these regional processes, the United States Geological Survey (USGS) conducted a study to better understand the geologic structure of the San Diego area. A cornerstone of this study is the installation and analysis of 77 wells at 12 multiple-depth monitoring-well sites. Geologic information from these wells was combined with lithologic data from 81 oil exploration wells and municipal and private water wells, gravity and seismic interpretations, and paleontological interpretations. These data were analyzed in conjunction with geologic maps and digital elevation models to develop a 3D geologic model of the San Diego area, in particular of the San Diego embayment. Existing interpretations of regional surficial geology, faulting, and tectonic history provided the framework for this model, which was refined by independent evaluation of subsurface geology. Geologic formations were simplified into five sedimentary units (Quaternary, Plio-Pleistocene, Oligocene, Eocene and Cretaceous ages), and one basal crystalline unit (primarily Cretaceous and Jurassic). Complex fault systems are represented in the model by ten fault strands that maintain overall displacement. The 3D geologic model corroborates existing geologic concepts of the San Diego area, refines the extent of subsurface geology, and allows users to holistically evaluate subsurface structures and regional hydrogeology.

  2. Quantification and geometric analysis of coiling patterns in gastropod shells based on 3D and 2D image data.

    PubMed

    Noshita, Koji

    2014-12-21

    The morphology of gastropod shells has been a focus of analyses in ecology and evolution. It has recently emerged as an important issue in developmental biology, thanks to recent advancements in molecular biological techniques. The growing tube model is a theoretical morphological model for describing various coiling patterns of molluscan shells, and it is a useful theoretical tool to relate local tissue growth with global shell morphology. However, the growing tube model has rarely been adopted in empirical research owing to the difficulty in estimating the parameters of the model from morphological data. In this article, I solve this problem by developing methods of parameter estimation when (1) 3D Computed Tomography (CT) data are available and (2) only 2D image data (such as photographs) are available. When 3D CT data are available, the parameters can be estimated by fitting an analytical solution of the growing tube model to the data. When only 2D image data are available, we first fit Raup׳s model to the 2D image data and then convert the parameters of Raup׳s model to those of the growing tube model. To illustrate the use of these methods, I apply them to data generated by a computer simulation of the model. Both methods work well, except when shells grow without coiling. I also demonstrate the effectiveness of the methods by applying the model to actual 3D CT data and 2D image data of land snails. I conclude that the method proposed in this article can reconstruct the coiling pattern from observed data.

  3. 3D flare particle model for ShipIR/NTCS

    NASA Astrophysics Data System (ADS)

    Ramaswamy, Srinivasan; Vaitekunas, David A.

    2016-05-01

    A key component in any soft-kill response to an incoming guided missile is the flare /chaff decoy used to distract or seduce the seeker homing system away from the naval platform. This paper describes a new 3D flare particle model in the naval threat countermeasure simulator (NTCS) of the NATO-standard ship signature model (ShipIR), which provides independent control over the size and radial distribution of its signature. The 3D particles of each flare sub-munition are modelled stochastically and rendered using OpenGL z-buffering, 2D projection, and alpha-blending to produce a unique and time varying signature. A sensitivity analysis on each input parameter provides the data and methods needed to synthesize a model from an IR measurement of a decoy. The new model also eliminated artifacts and deficiencies in our previous model which prevented reliable tracks from the adaptive track gate algorithm already presented by Ramaswamy and Vaitekunas (2015). A sequence of scenarios are used to test and demonstrate the new flare model during a missile engagement.

  4. Modeling Extracellular Matrix Reorganization in 3D Environments

    PubMed Central

    Harjanto, Dewi; Zaman, Muhammad H.

    2013-01-01

    Extracellular matrix (ECM) remodeling is a key physiological process that occurs in a number of contexts, including cell migration, and is especially important for cellular form and function in three-dimensional (3D) matrices. However, there have been few attempts to computationally model how cells modify their environment in a manner that accounts for both cellular properties and the architecture of the surrounding ECM. To this end, we have developed and validated a novel model to simulate matrix remodeling that explicitly defines cells in a 3D collagenous matrix. In our simulation, cells can degrade, deposit, or pull on local fibers, depending on the fiber density around each cell. The cells can also move within the 3D matrix. Different cell phenotypes can be modeled by varying key cellular parameters. Using the model we have studied how two model cancer cell lines, of differing invasiveness, modify matrices with varying fiber density in their vicinity by tracking the metric of fraction of matrix occupied by fibers. Our results quantitatively demonstrate that in low density environments, cells deposit more collagen to uniformly increase fibril fraction. On the other hand, in higher density environments, the less invasive model cell line reduced the fibril fraction as compared to the highly invasive phenotype. These results show good qualitative and quantitative agreement with existing experimental literature. Our simulation is therefore able to function as a novel platform to provide new insights into the clinically relevant and physiologically critical process of matrix remodeling by helping identify critical parameters that dictate cellular behavior in complex native-like environments. PMID:23341900

  5. 3D statistical shape models incorporating 3D random forest regression voting for robust CT liver segmentation

    NASA Astrophysics Data System (ADS)

    Norajitra, Tobias; Meinzer, Hans-Peter; Maier-Hein, Klaus H.

    2015-03-01

    During image segmentation, 3D Statistical Shape Models (SSM) usually conduct a limited search for target landmarks within one-dimensional search profiles perpendicular to the model surface. In addition, landmark appearance is modeled only locally based on linear profiles and weak learners, altogether leading to segmentation errors from landmark ambiguities and limited search coverage. We present a new method for 3D SSM segmentation based on 3D Random Forest Regression Voting. For each surface landmark, a Random Regression Forest is trained that learns a 3D spatial displacement function between the according reference landmark and a set of surrounding sample points, based on an infinite set of non-local randomized 3D Haar-like features. Landmark search is then conducted omni-directionally within 3D search spaces, where voxelwise forest predictions on landmark position contribute to a common voting map which reflects the overall position estimate. Segmentation experiments were conducted on a set of 45 CT volumes of the human liver, of which 40 images were randomly chosen for training and 5 for testing. Without parameter optimization, using a simple candidate selection and a single resolution approach, excellent results were achieved, while faster convergence and better concavity segmentation were observed, altogether underlining the potential of our approach in terms of increased robustness from distinct landmark detection and from better search coverage.

  6. Digital 3D Borobudur - Integration of 3D surveying and modeling techniques

    NASA Astrophysics Data System (ADS)

    Suwardhi, D.; Menna, F.; Remondino, F.; Hanke, K.; Akmalia, R.

    2015-08-01

    The Borobudur temple (Indonesia) is one of the greatest Buddhist monuments in the world, now listed as an UNESCO World Heritage Site. The present state of the temple is the result of restorations after being exposed to natural disasters several times. Today there is still a growing rate of deterioration of the building stones whose causes need further researches. Monitoring programs, supported at institutional level, have been effectively executed to observe the problem. The paper presents the latest efforts to digitally document the Borobudur Temple and its surrounding area in 3D with photogrammetric techniques. UAV and terrestrial images were acquired to completely digitize the temple, produce DEM, orthoimages and maps at 1:100 and 1:1000 scale. The results of the project are now employed by the local government organizations to manage the heritage area and plan new policies for the conservation and preservation of the UNESCO site. In order to help data management and policy makers, a web-based information system of the heritage area was also built to visualize and easily access all the data and achieved 3D results.

  7. Full 3-D OCT-based pseudophakic custom computer eye model

    PubMed Central

    Sun, M.; Pérez-Merino, P.; Martinez-Enriquez, E.; Velasco-Ocana, M.; Marcos, S.

    2016-01-01

    We compared measured wave aberrations in pseudophakic eyes implanted with aspheric intraocular lenses (IOLs) with simulated aberrations from numerical ray tracing on customized computer eye models, built using quantitative 3-D OCT-based patient-specific ocular geometry. Experimental and simulated aberrations show high correlation (R = 0.93; p<0.0001) and similarity (RMS for high order aberrations discrepancies within 23.58%). This study shows that full OCT-based pseudophakic custom computer eye models allow understanding the relative contribution of optical geometrical and surgically-related factors to image quality, and are an excellent tool for characterizing and improving cataract surgery. PMID:27231608

  8. Optimization of 3D Poisson-Nernst-Planck model for fast evaluation of diverse protein channels.

    PubMed

    Dyrka, Witold; Bartuzel, Maciej M; Kotulska, Malgorzata

    2013-10-01

    We show the accuracy and applicability of our fast algorithmic implementation of a three-dimensional Poisson-Nernst-Planck (3D-PNP) flow model for characterizing different protein channels. Due to its high computational efficiency, our model can predict the full current-voltage characteristics of a channel within minutes, based on the experimental 3D structure of the channel or its computational model structure. Compared with other methods, such as Brownian dynamics, which currently needs a few weeks of the computational time, or even much more demanding molecular dynamics modeling, 3D-PNP is the only available method for a function-based evaluation of very numerous tentative structural channel models. Flow model tests of our algorithm and its optimal parametrization are provided for five native channels whose experimental structures are available in the protein data bank (PDB) in an open conductive state, and whose experimental current-voltage characteristics have been published. The channels represent very different geometric and structural properties, which makes it the widest test to date of the accuracy of 3D-PNP on real channels. We test whether the channel conductance, rectification, and charge selectivity obtained from the flow model, could be sufficiently sensitive to single-point mutations, related to unsignificant changes in the channel structure. Our results show that the classical 3D-PNP model, under proper parametrization, is able to achieve a qualitative agreement with experimental data for a majority of the tested characteristics and channels, including channels with narrow and irregular conductivity pores. We propose that although the standard PNP model cannot provide insight into complex physical phenomena due to its intrinsic limitations, its semiquantitative agreement is achievable for rectification and selectivity at a level sufficient for the bioinformatical purpose of selecting the best structural models with a great advantage of a very short

  9. 3-D modelling of seamount topography from satellite altimetry

    SciTech Connect

    Baudry, N. ); Calmant, S. )

    1991-06-01

    The authors develop a complete set of algorithms to perform 3D modelling of seamount bathymetry from satellite altimetry. The first stage of the data processing consists in gridding the geoid: to account for the long wavelength errors geoid heights are first bias-adjusted at cross-overs. Then a collocation on a regular grid is performed, accounting for the altimeter errors. In a second stage, geoid heights are converted into bathymetry. No simplifying assumption on the shape and location of the bathymetry highs is necessary. Bathymetric uncertainties due to the data sampling and the parameters of the mechanical and crustal models are evaluated.

  10. 3D Numerical Simulations of the Breakout Model

    NASA Astrophysics Data System (ADS)

    Choe, G. S.; Cheng, C. Z.; Lee, J.; Lynch, B. J.; Antiochos, S. K.; DeVore, C. R.; Zurbuchen, T. H.

    2005-05-01

    We present the continuing progress of the numerical simulations of the breakout model for coronal mass ejection initiation. To validate the 3D spherical ARMS code we have run the 2.5D breakout problem and compare the eruption to the published 2D results. The ARMS 2.5D CME also forms a large magnetic island ahead of the erupting plasmoid due to the code's excellent maintenance of equatorial symmetry. Progress on the fully 3D breakout problem is also discussed. To build up enough magnetic free energy for an eruption the active region field must be strong with a steep gradient near the polarity inversion line and the shear must be highly concentrated there. This requires adaptive griding techniques. In the current simulation, the active region to background field ratio is 20-to-1 and the neutral line is long compared to the active region width. We present the evolution of this topology under Br-conserving shearing flow and discuss implications for a 3D eruption. This work is supported by NASA and ONR. BJL is supported by NASA GSRP grant NGT5-50453.

  11. Discrete Method of Images for 3D Radio Propagation Modeling

    NASA Astrophysics Data System (ADS)

    Novak, Roman

    2016-09-01

    Discretization by rasterization is introduced into the method of images (MI) in the context of 3D deterministic radio propagation modeling as a way to exploit spatial coherence of electromagnetic propagation for fine-grained parallelism. Traditional algebraic treatment of bounding regions and surfaces is replaced by computer graphics rendering of 3D reflections and double refractions while building the image tree. The visibility of reception points and surfaces is also resolved by shader programs. The proposed rasterization is shown to be of comparable run time to that of the fundamentally parallel shooting and bouncing rays. The rasterization does not affect the signal evaluation backtracking step, thus preserving its advantage over the brute force ray-tracing methods in terms of accuracy. Moreover, the rendering resolution may be scaled back for a given level of scenario detail with only marginal impact on the image tree size. This allows selection of scene optimized execution parameters for faster execution, giving the method a competitive edge. The proposed variant of MI can be run on any GPU that supports real-time 3D graphics.

  12. Modeling the GFR with RELAP5-3D

    SciTech Connect

    Cliff B. Davis; Theron D. Marshall; K. D. Weaver

    2005-09-01

    Significant improvements have been made to the RELAP5-3D computer code for analysis of the Gas Fast Reactor (GFR). These improvements consisted of adding carbon dioxide as a working fluid, improving the turbine component, developing a compressor model, and adding the Gnielinski heat transfer correlation. The code improvements were validated, generally through comparisons with independent design calculations. A model of the power conversion unit of the GFR was developed. The model of the power conversion unit was coupled to a reactor model to develop a complete model of the GFR system. The RELAP5 model of the GFR was used to simulate two transients, one initiated by a reactor trip and the other initiated by a loss of load.

  13. Testing Mercury Porosimetry with 3D Printed Porosity Models

    NASA Astrophysics Data System (ADS)

    Hasiuk, F.; Ewing, R. P.; Hu, Q.

    2014-12-01

    Mercury intrusion porosimetry is one of the most widely used techniques to study the porous nature of a geological and man-made materials. In the geosciences, it is commonly used to describe petroleum reservoir and seal rocks as well as to grade aggregates for the design of asphalt and portland cement concretes. It's wide utility stems from its ability to characterize a wide range of pore throat sizes (from nanometers to around a millimeter). The fundamental physical model underlying mercury intrusion porosimetry, the Washburn Equation, is based on the assumption that rock porosity can be described as a bundle of cylindrical tubes. 3D printing technology, also known as rapid prototyping, allows the construction of intricate and accurate models, exactly what is required to build models of rock porosity. We evaluate the applicability of the Washburn Equation by comparing properties (like porosity, pore and pore throat size distribution, and surface area) computed on digital porosity models (built from CT data, CAD designs, or periodic geometries) to properties measured via mercury intrusion porosimetry on 3D printed versions of the same digital porosity models.

  14. DYNA3D Material Model 71 - Solid Element Test Problem

    SciTech Connect

    Zywicz, E

    2008-01-24

    A general phenomenological-based elasto-plastic nonlinear isotropic strain hardening material model was implemented in DYNA3D for use in solid, beam, truss, and shell elements. The constitutive model, Model 71, is based upon conventional J2 plasticity and affords optional temperature and rate dependence (visco-plasticity). The expressions for strain hardening, temperature dependence, and rate dependence allow it to represent a wide variety of material responses. Options to capture temperature changes due to adiabatic heating and thermal straining are incorporated into the constitutive framework as well. The verification problem developed for this constitutive model consists of four uni-axial right cylinders subject to constant true strain-rate boundary conditions. Three of the specimens have different constant strain rates imposed, while the fourth specimen is subjected to several strain rate jumps. The material parameters developed by Fehlmann (2005) for 21-6-9 Nitronic steel are utilized. As demonstrated below, the finite element (FE) simulations are in excellent agreement with the theoretical responses and indicated the model is functioning as desired. Consequently, this problem serves as both a verification problem and regression test problem for DYNA3D.

  15. Modeling radiative transfer in heterogeneous 3D vegetation canopies

    NASA Astrophysics Data System (ADS)

    Gastellu-Etchegorry, J. P.; Demarez, V.; Pinel, Veronique; Zagolski, Francis

    1995-01-01

    The DART (discrete anisotropic radiative transfer) model simulates radiative transfer in heterogeneous 3-D scenes; here, a forest plantation. Similarly to Kimes model, the scene is divided into a rectangular cell matrix, i.e., a building block for simulating larger scenes. Cells are parallelipipedic. The scene encompasses different landscape features (i.e., trees with leaves and trunks, grass, water, and soil) with specific optical (reflectance, transmittance) and structural (LAI, LAD) characteristics. Radiation directions are subdivided into contiguous sectors with possibly uneven spacing. Topography, hot spot, and multiple interactions (scattering, attenuation) within cells are modeled. Two major steps are distinguished: (1) Illumination of cells by direct sun radiation. Actual locations of within cell scattering are determined for optimizing scattering computation. (2) Interception and scattering of previously scattered radiation. Diffuse atmospheric radiation is input at this level. Multiple scattering is represented with a spherical harmonic decomposition, for reducing data volume. The model iterates on step 2 for all cells, and stops with the energetic equilibrium. This model predicts the bi-directional reflectance factors of 3D canopies, with each scene component contribution; it was successfully tested with homogeneous covers. It gives also the radiation regime with canopies, and consequently some information about volume distribution of photosynthesis rates and primary production.

  16. Complex tephra dispersion from 3D plume modeling using ATHAM

    NASA Astrophysics Data System (ADS)

    Nicholson, B. C.; Kobs-Nawotniak, S. E.

    2014-12-01

    Most volcanic hazard assessments are based on a classic inversion tool for tephra deposits that relies on a simple integral model to explain the eruption plume. While this tool is adequate for first-order predictions of tephra deposition under no-wind conditions, the simplifying assumptions make it unreliable for ambient winds >10 m/s. Advances in computational power now make it possible to improve the inversion tool using 3D fluid dynamics. We do this with the physics-based Active Tracer High-resolution Atmospheric Model (ATHAM) to model tephra dispersion and deposition from volcanic eruption columns. The model, when run in 3D, is able to capture the complex morphology of bent plumes. Tephra distributions produced by these morphologies differ significantly from distributions created by idealized advection solutions, reflecting the effects of counter-rotating vortex pairs, puffing modes, or plume bifurcation. The modeled tephra deposition better captures the complex effects of wind-plume interaction, allowing us to update classic inversion tools with more realistic weak plume conditions consistent with typical historical explosive eruptions.

  17. 3-D physical modeling of a complex salt canopy

    SciTech Connect

    Wiley, R.W.; Sekharan, K.K.

    1996-12-31

    Recent drilling has confirmed both significant reservoir potential and the presence of commercial hydrocarbons below salt structures in the Gulf of Mexico. Obtaining definitive seismic images with standard processing schemes beneath these salt structures is very difficult if not impossible. Because of the complicated seismic behavior of these structures, full volume 3-D prestack depth migration is required. Unfortunately, carrying out the multitude of calculations needed to create a proper image requires the largest and fastest supercomputers and rather complex numerical algorithms. Furthermore, developing and testing the imaging algorithms is quite involved and requires appropriate test data sets. To better understand the problems and issues of subsalt imaging, Marathon Oil Company and Louisiana Land and Exploration Company contracted with the University of Houston`s Allied Geophysical Laboratories (AGL) to construct a salt canopy physical model. The model is patterned after the SEG/EAEG Salt Model and is made from synthetic materials. It is a full three-dimensional model with an irregularly shaped, lateral salt structure embedded in five distinct sedimentary layers. The model was used to acquire a multi-offset 3-D marine-style survey. These data are being used to address problems of subsalt imaging. In addition to standard processing techniques, the authors investigate algorithms for multiple removal and prestack depth migration.

  18. On 3-D inelastic analysis methods for hot section components. Volume 1: Special finite element models

    NASA Technical Reports Server (NTRS)

    Nakazawa, S.

    1988-01-01

    This annual status report presents the results of work performed during the fourth year of the 3-D Inelastic Analysis Methods for Hot Section Components program (NASA Contract NAS3-23697). The objective of the program is to produce a series of new computer codes permitting more accurate and efficient 3-D analysis of selected hot section components, i.e., combustor liners, turbine blades and turbine vanes. The computer codes embody a progression of math models and are streamlined to take advantage of geometrical features, loading conditions, and forms of material response that distinguish each group of selected components. Volume 1 of this report discusses the special finite element models developed during the fourth year of the contract.

  19. Exploiting Textured 3D Models for Developing Serious Games

    NASA Astrophysics Data System (ADS)

    Kontogianni, G.; Georgopoulos, A.

    2015-08-01

    Digital technologies have affected significantly many fields of computer graphics such as Games and especially the field of the Serious Games. These games are usually used for educational proposes in many fields such as Health Care, Military applications, Education, Government etc. Especially Digital Cultural Heritage is a scientific area that Serious Games are applied and lately many applications appear in the related literature. Realistic 3D textured models which have been produced using different photogrammetric methods could be a useful tool for the creation of Serious Game applications in order to make the final result more realistic and close to the reality. The basic goal of this paper is how 3D textured models which are produced by photogrammetric methods can be useful for developing a more realistic environment of a Serious Game. The application of this project aims at the creation of an educational game for the Ancient Agora of Athens. The 3D models used vary not only as far as their production methods (i.e. Time of Flight laser scanner, Structure from Motion, Virtual historical reconstruction etc.) is concerned, but also as far as their era as some of them illustrated according to their existing situation and some others according to how these monuments looked like in the past. The Unity 3D® game developing environment was used for creating this application, in which all these models were inserted in the same file format. For the application two diachronic virtual tours of the Athenian Agora were produced. The first one illustrates the Agora as it is today and the second one at the 2nd century A.D. Finally the future perspective for the evolution of this game is presented which includes the addition of some questions that the user will be able to answer. Finally an evaluation is scheduled to be performed at the end of the project.

  20. 3D model tools for architecture and archaeology reconstruction

    NASA Astrophysics Data System (ADS)

    Vlad, Ioan; Herban, Ioan Sorin; Stoian, Mircea; Vilceanu, Clara-Beatrice

    2016-06-01

    The main objective of architectural and patrimonial survey is to provide a precise documentation of the status quo of the surveyed objects (monuments, buildings, archaeological object and sites) for preservation and protection, for scientific studies and restoration purposes, for the presentation to the general public. Cultural heritage documentation includes an interdisciplinary approach having as purpose an overall understanding of the object itself and an integration of the information which characterize it. The accuracy and the precision of the model are directly influenced by the quality of the measurements realized on field and by the quality of the software. The software is in the process of continuous development, which brings many improvements. On the other side, compared to aerial photogrammetry, close range photogrammetry and particularly architectural photogrammetry is not limited to vertical photographs with special cameras. The methodology of terrestrial photogrammetry has changed significantly and various photographic acquisitions are widely in use. In this context, the present paper brings forward a comparative study of TLS (Terrestrial Laser Scanner) and digital photogrammetry for 3D modeling. The authors take into account the accuracy of the 3D models obtained, the overall costs involved for each technology and method and the 4th dimension - time. The paper proves its applicability as photogrammetric technologies are nowadays used at a large scale for obtaining the 3D model of cultural heritage objects, efficacious in their assessment and monitoring, thus contributing to historic conservation. Its importance also lies in highlighting the advantages and disadvantages of each method used - very important issue for both the industrial and scientific segment when facing decisions such as in which technology to invest more research and funds.

  1. The Engelbourg's ruins: from 3D TLS point cloud acquisition to 3D virtual and historic models

    NASA Astrophysics Data System (ADS)

    Koehl, Mathieu; Berger, Solveig; Nobile, Sylvain

    2014-05-01

    The Castle of Engelbourg was built at the beginning of the 13th century, at the top of the Schlossberg. It is situated on the territory of the municipality of Thann (France), at the crossroads of Alsace and Lorraine, and dominates the outlet of the valley of Thur. Its strategic position was one of the causes of its systematic destructions during the 17th century, and Louis XIV finished his fate by ordering his demolition in 1673. Today only few vestiges remain, of which a section of the main tower from about 7m of diameter and 4m of wide laying on its slice, unique characteristic in the regional castral landscape. It is visible since the valley, was named "the Eye of the witch", and became a key attraction of the region. The site, which extends over approximately one hectare, is for several years the object of numerous archaeological studies and is at the heart of a project of valuation of the vestiges today. It was indeed a key objective, among the numerous planned works, to realize a 3D model of the site in its current state, in other words, a virtual model "such as seized", exploitable as well from a cultural and tourist point of view as by scientists and in archaeological researches. The team of the ICube/INSA lab had in responsibility the realization of this model, the acquisition of the data until the delivery of the virtual model, thanks to 3D TLS and topographic surveying methods. It was also planned to integrate into this 3D model, data of 2D archives, stemming from series of former excavations. The objectives of this project were the following ones: • Acquisition of 3D digital data of the site and 3D modelling • Digitization of the 2D archaeological data and integration in the 3D model • Implementation of a database connected to the 3D model • Virtual Visit of the site The obtained results allowed us to visualize every 3D object individually, under several forms (point clouds, 3D meshed objects and models, etc.) and at several levels of detail

  2. Nonintrusive 3D reconstruction of human bone models to simulate their bio-mechanical response

    NASA Astrophysics Data System (ADS)

    Alexander, Tsouknidas; Antonis, Lontos; Savvas, Savvakis; Nikolaos, Michailidis

    2012-06-01

    3D finite element models representing functional parts of the human skeletal system, have been repeatedly introduced over the last years, to simulate biomechanical response of anatomical characteristics or investigate surgical treatment. The reconstruction of geometrically accurate FEM models, poses a significant challenge for engineers and physicians, as recent advances in tissue engineering dictate highly customized implants, while facilitating the production of alloplast materials that are employed to restore, replace or supplement the function of human tissue. The premises of every accurate reconstruction method, is to encapture the precise geometrical characteristics of the examined tissue and thus the selection of a sufficient imaging technique is of the up-most importance. This paper reviews existing and potential applications related to the current state-of-the-art of medical imaging and simulation techniques. The procedures are examined by introducing their concepts; strengths and limitations, while the authors also present part of their recent activities in these areas. [Figure not available: see fulltext.

  3. Modeling moving systems with RELAP5-3D

    SciTech Connect

    Mesina, G. L.; Aumiller, David L.; Buschman, Francis X.; Kyle, Matt R.

    2015-12-04

    RELAP5-3D is typically used to model stationary, land-based reactors. However, it can also model reactors in other inertial and accelerating frames of reference. By changing the magnitude of the gravitational vector through user input, RELAP5-3D can model reactors on a space station or the moon. The field equations have also been modified to model reactors in a non-inertial frame, such as occur in land-based reactors during earthquakes or onboard spacecraft. Transient body forces affect fluid flow in thermal-fluid machinery aboard accelerating crafts during rotational and translational accelerations. It is useful to express the equations of fluid motion in the accelerating frame of reference attached to the moving craft. However, careful treatment of the rotational and translational kinematics is required to accurately capture the physics of the fluid motion. Correlations for flow at angles between horizontal and vertical are generated via interpolation where no experimental studies or data exist. The equations for three-dimensional fluid motion in a non-inertial frame of reference are developed. As a result, two different systems for describing rotational motion are presented, user input is discussed, and an example is given.

  4. Modeling moving systems with RELAP5-3D

    DOE PAGES

    Mesina, G. L.; Aumiller, David L.; Buschman, Francis X.; ...

    2015-12-04

    RELAP5-3D is typically used to model stationary, land-based reactors. However, it can also model reactors in other inertial and accelerating frames of reference. By changing the magnitude of the gravitational vector through user input, RELAP5-3D can model reactors on a space station or the moon. The field equations have also been modified to model reactors in a non-inertial frame, such as occur in land-based reactors during earthquakes or onboard spacecraft. Transient body forces affect fluid flow in thermal-fluid machinery aboard accelerating crafts during rotational and translational accelerations. It is useful to express the equations of fluid motion in the acceleratingmore » frame of reference attached to the moving craft. However, careful treatment of the rotational and translational kinematics is required to accurately capture the physics of the fluid motion. Correlations for flow at angles between horizontal and vertical are generated via interpolation where no experimental studies or data exist. The equations for three-dimensional fluid motion in a non-inertial frame of reference are developed. As a result, two different systems for describing rotational motion are presented, user input is discussed, and an example is given.« less

  5. Fisheye Lenses for 3d Modeling: Evaluations and Considerations

    NASA Astrophysics Data System (ADS)

    Barazzetti, L.; Previtali, M.; Roncoroni, F.

    2017-02-01

    Fisheye lenses are becoming more popular in complete image-based modelling projects of small and narrow spaces. The growing interest in fisheye lenses is confirmed by the availability of different commercial software incorporating a fisheye camera model. Such software are now able to carry out the steps of the image processing pipeline in a fully automated way, from camera calibration and orientation to dense matching, surface generation, and orthophoto production. This paper highlights the advantages (and disadvantages) of fisheye lenses when used for 3D modelling projects through different commercial software. The goal is not only a comparison of commercial software, but also an analysis of the additional issues that arise when a fisheye lens is used for 3D modelling. Results confirm that a fisheye lens is suitable for accurate metric documentation, especially when limited space is available. On the other hand, additional issues where found during the camera calibration/image orientation step as well as the texture generation and orthophoto production phases, for which particular attention is required.

  6. ShrinkWrap: 3D model abstraction for remote sensing simulation

    SciTech Connect

    Pope, Paul A

    2009-01-01

    Remote sensing simulations often require the use of 3D models of objects of interest. There are a multitude of these models available from various commercial sources. There are image processing, computational, database storage, and . data access advantages to having a regularized, encapsulating, triangular mesh representing the surface of a 3D object model. However, this is usually not how these models are stored. They can have too much detail in some areas, and not enough detail in others. They can have a mix of planar geometric primitives (triangles, quadrilaterals, n-sided polygons) representing not only the surface of the model, but also interior features. And the exterior mesh is usually not regularized nor encapsulating. This paper presents a method called SHRlNKWRAP which can be used to process 3D object models to achieve output models having the aforementioned desirable traits. The method works by collapsing an encapsulating sphere, which has a regularized triangular mesh on its surface, onto the surface of the model. A GUI has been developed to make it easy to leverage this capability. The SHRlNKWRAP processing chain and use of the GUI are described and illustrated.

  7. 3-d Periodic Packaging: Sodalite, a Model System

    DTIC Science & Technology

    1992-05-15

    to 05-31-92 4. TITLE AND SUBTITLE S. FUNDING NUMBERS 3-d Periodic Packaging: N00014-90-J-1159 Sodalite , A Model System 6. AUTHOR(S) G.D. Stucky, V.I...assembly of confined atomic and molecular arrays. Sodalite , one of the simplest zeolite analogue structures with a 60 atom cage can be synthesized with...structure of both the frameworks and the clusters within the cages of sodalite structural analogues can be precisely determined. In addition to new

  8. 3-D Periodic Packaging: Sodalite, a Model System

    DTIC Science & Technology

    1992-05-15

    hfww 05-15-92 Technical 06-1-91 o 05-31-92 ,mA AMU SUBSTIl SI. FUNDING NUMBUS 3-d Periodic Packaging: Sodalite , A Model System N00014-81-K-0598 AUTNO(S...considerable latitude in the assembly of confined atomic and molecular arrays. Sodalite , one of the simplest zeolite analogue structures with a 60 atom...framework electric field. The structure of both the fiameworks and the clusters within the cages of sodalite structural analogues can be precisely

  9. 3-D Model of Earthquake Sources in the Los Angeles Basin, CA

    NASA Astrophysics Data System (ADS)

    Plesch, A.; Shaw, J. H.

    2001-12-01

    We present a digital 3d model of the major, seismogenic fault system in the Los Angeles basin. The model is a prototype for a community-based fault characterization effort initiated by the Southern California Earthquake Center, Phase 2 (SCEC2). Faults were selected by consensus within the SCEC2 community based on geologic relevance, perceived hazard, and quality of descriptive data. Our first iteration model was populated with most of the important faults and with the deformed basement surface, which represents the main velocity interface in the basin. Constraints on fault geometries and positions include surface traces, surficial neotectonic data, seismic reflection profiles, wells, cross-sections, hypocentral locations, and focal mechanisms. Accurate geospatial registration proved essential. We use advanced geometric modeling software to integrate these various geophysical and geologic data in a 3d space, and to interpolate and extrapolate the fault surfaces. The model describes the geometry of imbricated blind-thrust faults that underlie the northern Los Angeles basin (Puente Hills, Las Cienegas, San Vicente, Elysian Park), as well as the basin bounding structures including the Santa Monica, Sierra Madre, and Cucamonga systems. In the case of the Santa Monica thrust, the 3d construction suggests the presence of a previously undocumented blind extension of this system to the northeast, below the Hollywood fault, and perhaps coinciding in parts with the North Salt Lake fault. The model also describes the 3D geometry of the major strike-slip systems in the basin, including the Newport-Inglewood and Whittier faults. The model provides a medium to investigate the spatial and temporal interactions of these fault systems based on their precise 3D geometries.

  10. Computational model of mesenchymal migration in 3D under chemotaxis

    PubMed Central

    Ribeiro, F. O.; Gómez-Benito, M. J.; Folgado, J.; Fernandes, P. R.; García-Aznar, J. M.

    2017-01-01

    Abstract Cell chemotaxis is an important characteristic of cellular migration, which takes part in crucial aspects of life and development. In this work, we propose a novel in silico model of mesenchymal 3D migration with competing protrusions under a chemotactic gradient. Based on recent experimental observations, we identify three main stages that can regulate mesenchymal chemotaxis: chemosensing, dendritic protrusion dynamics and cell–matrix interactions. Therefore, each of these features is considered as a different module of the main regulatory computational algorithm. The numerical model was particularized for the case of fibroblast chemotaxis under a PDGF-bb gradient. Fibroblasts migration was simulated embedded in two different 3D matrices – collagen and fibrin – and under several PDGF-bb concentrations. Validation of the model results was provided through qualitative and quantitative comparison with in vitro studies. Our numerical predictions of cell trajectories and speeds were within the measured in vitro ranges in both collagen and fibrin matrices. Although in fibrin, the migration speed of fibroblasts is very low, because fibrin is a stiffer and more entangling matrix. Testing PDGF-bb concentrations, we noticed that an increment of this factor produces a speed increment. At 1 ng mL−1 a speed peak is reached after which the migration speed diminishes again. Moreover, we observed that fibrin exerts a dampening behavior on migration, significantly affecting the migration efficiency. PMID:27336322

  11. Computational model of mesenchymal migration in 3D under chemotaxis.

    PubMed

    Ribeiro, F O; Gómez-Benito, M J; Folgado, J; Fernandes, P R; García-Aznar, J M

    2017-01-01

    Cell chemotaxis is an important characteristic of cellular migration, which takes part in crucial aspects of life and development. In this work, we propose a novel in silico model of mesenchymal 3D migration with competing protrusions under a chemotactic gradient. Based on recent experimental observations, we identify three main stages that can regulate mesenchymal chemotaxis: chemosensing, dendritic protrusion dynamics and cell-matrix interactions. Therefore, each of these features is considered as a different module of the main regulatory computational algorithm. The numerical model was particularized for the case of fibroblast chemotaxis under a PDGF-bb gradient. Fibroblasts migration was simulated embedded in two different 3D matrices - collagen and fibrin - and under several PDGF-bb concentrations. Validation of the model results was provided through qualitative and quantitative comparison with in vitro studies. Our numerical predictions of cell trajectories and speeds were within the measured in vitro ranges in both collagen and fibrin matrices. Although in fibrin, the migration speed of fibroblasts is very low, because fibrin is a stiffer and more entangling matrix. Testing PDGF-bb concentrations, we noticed that an increment of this factor produces a speed increment. At 1 ng mL(-1) a speed peak is reached after which the migration speed diminishes again. Moreover, we observed that fibrin exerts a dampening behavior on migration, significantly affecting the migration efficiency.

  12. Simulation of 3D Global Wave Propagation Through Geodynamic Models

    NASA Astrophysics Data System (ADS)

    Schuberth, B.; Piazzoni, A.; Bunge, H.; Igel, H.; Steinle-Neumann, G.

    2005-12-01

    This project aims at a better understanding of the forward problem of global 3D wave propagation. We use the spectral element program "SPECFEM3D" (Komatitsch and Tromp, 2002a,b) with varying input models of seismic velocities derived from mantle convection simulations (Bunge et al., 2002). The purpose of this approach is to obtain seismic velocity models independently from seismological studies. In this way one can test the effects of varying parameters of the mantle convection models on the seismic wave field. In order to obtain the seismic velocities from the temperature field of the geodynamical simulations we follow a mineral physics approach. Assuming a certain mantle composition (e.g. pyrolite with CMASF composition) we compute the stable phases for each depth (i.e. pressure) and temperature by system Gibbs free energy minimization. Elastic moduli and density are calculated from the equations of state of the stable mineral phases. For this we use a mineral physics database derived from calorimetric experiments (enthalphy and entropy of formation, heat capacity) and EOS parameters.

  13. Image sequence coding using 3D scene models

    NASA Astrophysics Data System (ADS)

    Girod, Bernd

    1994-09-01

    The implicit and explicit use of 3D models for image sequence coding is discussed. For implicit use, a 3D model can be incorporated into motion compensating prediction. A scheme that estimates the displacement vector field with a rigid body motion constraint by recovering epipolar lines from an unconstrained displacement estimate and then repeating block matching along the epipolar line is proposed. Experimental results show that an improved displacement vector field can be obtained with a rigid body motion constraint. As an example for explicit use, various results with a facial animation model for videotelephony are discussed. A 13 X 16 B-spline mask can be adapted automatically to individual faces and is used to generate facial expressions based on FACS. A depth-from-defocus range camera suitable for real-time facial motion tracking is described. Finally, the real-time facial animation system `Traugott' is presented that has been used to generate several hours of broadcast video. Experiments suggest that a videophone system based on facial animation might require a transmission bitrate of 1 kbit/s or below.

  14. Pose invariant face recognition: 3D model from single photo

    NASA Astrophysics Data System (ADS)

    Napoléon, Thibault; Alfalou, Ayman

    2017-02-01

    Face recognition is widely studied in the literature for its possibilities in surveillance and security. In this paper, we report a novel algorithm for the identification task. This technique is based on an optimized 3D modeling allowing to reconstruct faces in different poses from a limited number of references (i.e. one image by class/person). Particularly, we propose to use an active shape model to detect a set of keypoints on the face necessary to deform our synthetic model with our optimized finite element method. Indeed, in order to improve our deformation, we propose a regularization by distances on graph. To perform the identification we use the VanderLugt correlator well know to effectively address this task. On the other hand we add a difference of Gaussian filtering step to highlight the edges and a description step based on the local binary patterns. The experiments are performed on the PHPID database enhanced with our 3D reconstructed faces of each person with an azimuth and an elevation ranging from -30° to +30°. The obtained results prove the robustness of our new method with 88.76% of good identification when the classic 2D approach (based on the VLC) obtains just 44.97%.

  15. Heralding a new paradigm in 3D tumor modeling.

    PubMed

    Fong, Eliza L S; Harrington, Daniel A; Farach-Carson, Mary C; Yu, Hanry

    2016-11-01

    Numerous studies to date have contributed to a paradigm shift in modeling cancer, moving from the traditional two-dimensional culture system to three-dimensional (3D) culture systems for cancer cell culture. This led to the inception of tumor engineering, which has undergone rapid advances over the years. In line with the recognition that tumors are not merely masses of proliferating cancer cells but rather, highly complex tissues consisting of a dynamic extracellular matrix together with stromal, immune and endothelial cells, significant efforts have been made to better recapitulate the tumor microenvironment in 3D. These approaches include the development of engineered matrices and co-cultures to replicate the complexity of tumor-stroma interactions in vitro. However, the tumor engineering and cancer biology fields have traditionally relied heavily on the use of cancer cell lines as a cell source in tumor modeling. While cancer cell lines have contributed to a wealth of knowledge in cancer biology, the use of this cell source is increasingly perceived as a major contributing factor to the dismal failure rate of oncology drugs in drug development. Backing this notion is the increasing evidence that tumors possess intrinsic heterogeneity, which predominantly homogeneous cancer cell lines poorly reflect. Tumor heterogeneity contributes to therapeutic resistance in patients. To overcome this limitation, cancer cell lines are beginning to be replaced by primary tumor cell sources, in the form of patient-derived xenografts and organoids cultures. Moving forward, we propose that further advances in tumor engineering would require that tumor heterogeneity (tumor variants) be taken into consideration together with tumor complexity (tumor-stroma interactions). In this review, we provide a comprehensive overview of what has been achieved in recapitulating tumor complexity, and discuss the importance of incorporating tumor heterogeneity into 3D in vitro tumor models. This

  16. a Unified Approach for 3d Generalization of Building Models in Citygml

    NASA Astrophysics Data System (ADS)

    Baig, S. U.; Rahman, A. A.

    2013-05-01

    Task-specific applications demand abstractions (generalized) 3D scenes of 3D models to be used for visualization and analysis purposes. Therefore, lower LoDs (level-of-details) from higher LoDs need to be made available to these applications. A unified generalization framework is proposed to derive multiple LoDs (LoD3-LoD1) taking both semantics and geometric aspects of 3D buildings modelled in CityGML (City Geography Markup Language) into account. For this purpose, interior structures of 3D objects at LoD4 are removed to derive LoD3 and openings (door, windows) are removed from LoD3 to derive LoD2. Remaining parts such as outer installations and walls are projected onto the ground and simplified based on CityGML generalization specifications. Algorithms for simplification with the aim to derive LoD1 from LoD2 are implemented and tested on a number of buildings of Putrajaya city, Malaysia.The experiments shows that elimination of important part (s) or merging could be avoided by applying semantic-based removal of objects at different LoDs.

  17. A Prototype Digital Library for 3D Collections: Tools To Capture, Model, Analyze, and Query Complex 3D Data.

    ERIC Educational Resources Information Center

    Rowe, Jeremy; Razdan, Anshuman

    The Partnership for Research in Spatial Modeling (PRISM) project at Arizona State University (ASU) developed modeling and analytic tools to respond to the limitations of two-dimensional (2D) data representations perceived by affiliated discipline scientists, and to take advantage of the enhanced capabilities of three-dimensional (3D) data that…

  18. 3-D inelastic analysis methods for hot section components. Volume 2: Advanced special functions models

    NASA Technical Reports Server (NTRS)

    Wilson, R. B.; Banerjee, P. K.

    1987-01-01

    This Annual Status Report presents the results of work performed during the third year of the 3-D Inelastic Analysis Methods for Hot Sections Components program (NASA Contract NAS3-23697). The objective of the program is to produce a series of computer codes that permit more accurate and efficient three-dimensional analyses of selected hot section components, i.e., combustor liners, turbine blades, and turbine vanes. The computer codes embody a progression of mathematical models and are streamlined to take advantage of geometrical features, loading conditions, and forms of material response that distinguish each group of selected components.

  19. Canada in 3D - Toward a Sustainable 3D Model for Canadian Geology from Diverse Data Sources

    NASA Astrophysics Data System (ADS)

    Brodaric, B.; Pilkington, M.; Snyder, D. B.; St-Onge, M. R.; Russell, H.

    2015-12-01

    Many big science issues span large areas and require data from multiple heterogeneous sources, for example climate change, resource management, and hazard mitigation. Solutions to these issues can significantly benefit from access to a consistent and integrated geological model that would serve as a framework. However, such a model is absent for most large countries including Canada, due to the size of the landmass and the fragmentation of the source data into institutional and disciplinary silos. To overcome these barriers, the "Canada in 3D" (C3D) pilot project was recently launched by the Geological Survey of Canada. C3D is designed to be evergreen, multi-resolution, and inter-disciplinary: (a) it is to be updated regularly upon acquisition of new data; (b) portions vary in resolution and will initially consist of four layers (surficial, sedimentary, crystalline, and mantle) with intermediary patches of higher-resolution fill; and (c) a variety of independently managed data sources are providing inputs, such as geophysical, 3D and 2D geological models, drill logs, and others. Notably, scalability concerns dictate a decentralized and interoperable approach, such that only key control objects, denoting anchors for the modeling process, are imported into the C3D database while retaining provenance links to original sources. The resultant model is managed in the database, contains full modeling provenance as well as links to detailed information on rock units, and is to be visualized in desktop and online environments. It is anticipated that C3D will become the authoritative state of knowledge for the geology of Canada at a national scale.

  20. Recovering a collapsed medieval fresco by using 3D modeling techniques

    NASA Astrophysics Data System (ADS)

    Chiabrando, F.; Rinaudo, F.

    2014-05-01

    The paper presents the results of a reconstruction of the 3D model of a dome and of a medieval fresco, collapsed after an earthquake and now reconstructed in significant portions, to offer to the visitors a possible reconstruction of the lost masterpiece of medieval art. After the earthquake the collapsed dome was replaced by means of a concrete sphere connected with the survived portions of the old dome's timber. The old dome shape and the fresco were virtually reconstructed thanks to a set of historical pictures obtained by Italian, USA and German archives; those images have been calibrated and oriented by using modern digital photogrammetric approach and a realistic 3D model of the old inner surface of the dome has been realised. By using a LiDAR survey the 3D model of the apse and of the dome, has been set up and the boundaries between original and new structures have been reconstructed by visual evidences.The new dome has been virtually erased and the old dome with the fresco 3D model inserted allowing the reconstruction of the apse as it was before the earthquake. This virtual 3D model has been used to realise a 1:1 scale model of the old dome where the restorers fit some parts of the old fresco fragments recovered just after the earthquake, cleaned and classified. The fresco images correctly oriented inside the reconstructed dome have been projected on plane surfaces by using azimuthal orthographic projections of small portions of the dome in order to reduce the geometric deformations and to allow the mosaicking of these small planes onto a spherical surface.

  1. 3-D physical models of mitosis (with asters) and cytokinesis.

    PubMed

    Cheng, Kang; Zou, Changhua

    2004-01-01

    First, we define new concepts of Life Objects, Informative Objects and Virtual Objects, Discrete Chromosome Rings (DCR); we introduce a mathematical concept of meridian plane (MP) in a three dimensional (3-D) cylindrical coordinate system (CCS). Based on these concepts, classic mechanics, classic electromagnetism and published biological data, we develop our 3-D physical models of natural and normal mitosis (with asters) and cytokinesis, for animal cells in M phase. We propose following hypotheses: Chromosomes Exclusion: No normally and naturally replicated chromosomes can occupy the same nucleus without growing sizes of the nucleus and the cell. Spontaneous and strong electromagnetic fields (EMF) forces among chromosomes, centrosomes and microtubules split the nucleus and separate the two sets of sister chromatids when they are strong enough. Nuclei Exclusion: No normally and naturally doubled nuclei can occupy the same cell if the doubled size of nuclei is not far smaller than size of the cell. The spontaneous and strong EMF forces in protoplasm (or cortex), separate two sets of chromosomes, spindles and poles, drive contractile proteins to the equator in cell cortex, and continue to guide and to transport free charged objects until complete the cytokinesis. Centrioles Exclusion: No naturally and normally doubled centrioles can occupy the same centrosome. The spontaneous and strong repulsive EMF forces are the primary cause for the exclusions. The principles of our models are also applied to mitosis and cytokinesis for lower plant cells, to that of multiple nuclei or mutant chromosomes, and to meiosis, for both animal cells and lower plant cells.

  2. High-resolution 3D digital models of artworks

    NASA Astrophysics Data System (ADS)

    Fontana, Raffaella; Gambino, Maria Chiara; Greco, Marinella; Pampaloni, Enrico; Pezzati, Luca; Scopigno, Roberto

    2003-10-01

    The measurement of the shape of an artwork usually requires a high-resolution instrumentation, in order to catch small details such as chisel marks, sculptural relieves, surface cracks, etc. 3D scanning techniques, together with new modeling software tools, allow a high fidelity reproduction of an artwork: these can be applied either to support and document its repair or for the realization of 3D archives and virtual museums. Starting from a high-resolution digital model of an object, a further step could be its reproduction by means of fast-prototyping techniques like stereo-lithography or electro-erosion. This work is aimed at showing the performance of a high-resolution laser scanner devoted to Cultural Heritage applications. The device is portable and very versatile, in order to allow in situ applications, accurate and reliable, so to capture intricate details. This laser profilometer has been used in a few surveys, the most significant of which are the monitoring the various phases of the restoration process of an ellenistic bronze (the Minerva of Arezzo, Florence), the cataloguing of some archaeological findings (from the Grotta della Poesia, Lecce) and the documenting of wooden panels surface conditions (the "Madonna del Cardellino" by Raffaello and "La Tebaide" by Beato Angelico).

  3. In Silico 3D Modeling of Binding Activities.

    PubMed

    Moro, Stefano; Sturlese, Mattia; Ciancetta, Antonella; Floris, Matteo

    2016-01-01

    In silico three-dimensional (3D) molecular modeling tools based upon the receptor/enzyme-ligand docking simulation in protein crystal structures and/or homology modeling of receptors have been reliably used in pharmacological research and development for decades. Molecular docking methodologies are helpful for revealing facets of activation and inactivation, thus improving mechanistic understanding and predicting molecular ligand binding activity, and they can have a high level of accuracy, and have also been explored and applied in chemical risk assessment. This computational approach is, however, only applicable for chemical hazard identification situations where the specific target receptor for a given chemical is known and the crystal structure/homology model of the receptor is available.

  4. Dynamic deformable models for 3D MRI heart segmentation

    NASA Astrophysics Data System (ADS)

    Zhukov, Leonid; Bao, Zhaosheng; Gusikov, Igor; Wood, John; Breen, David E.

    2002-05-01

    Automated or semiautomated segmentation of medical images decreases interstudy variation, observer bias, and postprocessing time as well as providing clincally-relevant quantitative data. In this paper we present a new dynamic deformable modeling approach to 3D segmentation. It utilizes recently developed dynamic remeshing techniques and curvature estimation methods to produce high-quality meshes. The approach has been implemented in an interactive environment that allows a user to specify an initial model and identify key features in the data. These features act as hard constraints that the model must not pass through as it deforms. We have employed the method to perform semi-automatic segmentation of heart structures from cine MRI data.

  5. Stochastic Modeling of Calcium in 3D Geometry

    PubMed Central

    Mazel, Tomáš; Raymond, Rebecca; Raymond-Stintz, Mary; Jett, Stephen; Wilson, Bridget S.

    2009-01-01

    Release of inflammatory mediators by mast cells in type 1 immediate-hypersensitivity allergic reactions relies on antigen-dependent increases in cytosolic calcium. Here, we used a series of electron microscopy images to build a 3D reconstruction representing a slice through a rat tumor mast cell, which then served as a basis for stochastic modeling of inositol-trisphosphate-mediated calcium responses. The stochastic approach was verified by reaction-diffusion modeling within the same geometry. Local proximity of the endoplasmic reticulum to either the plasma membrane or mitochondria is predicted to differentially impact local inositol trisphosphate receptor transport. The explicit consideration of organelle spatial relationships represents an important step toward building a comprehensive, realistic model of cellular calcium dynamics. PMID:19254531

  6. Sharing on Web 3d Models of Ancient Theatres. a Methodological Workflow

    NASA Astrophysics Data System (ADS)

    Scianna, A.; La Guardia, M.; Scaduto, M. L.

    2016-06-01

    In the last few years, the need to share on the Web the knowledge of Cultural Heritage (CH) through navigable 3D models has increased. This need requires the availability of Web-based virtual reality systems and 3D WEBGIS. In order to make the information available to all stakeholders, these instruments should be powerful and at the same time very user-friendly. However, research and experiments carried out so far show that a standardized methodology doesn't exist. All this is due both to complexity and dimensions of geometric models to be published, on the one hand, and to excessive costs of hardware and software tools, on the other. In light of this background, the paper describes a methodological approach for creating 3D models of CH, freely exportable on the Web, based on HTML5 and free and open source software. HTML5, supporting the WebGL standard, allows the exploration of 3D spatial models using most used Web browsers like Chrome, Firefox, Safari, Internet Explorer. The methodological workflow here described has been tested for the construction of a multimedia geo-spatial platform developed for three-dimensional exploration and documentation of the ancient theatres of Segesta and of Carthage, and the surrounding landscapes. The experimental application has allowed us to explore the potential and limitations of sharing on the Web of 3D CH models based on WebGL standard. Sharing capabilities could be extended defining suitable geospatial Web-services based on capabilities of HTML5 and WebGL technology.

  7. Development of an aquifer management model AQMAN3D

    USGS Publications Warehouse

    Puig, Juan Carlos; Rolon-Collazo, L. I.; Pagan-Trinidad, Ishmael; Krishna, J.H.; Quinones-Aponte, Vicente; Gomez-Gomez, Fernando; Morris, G.L.

    1990-01-01

    A computer code that enables the use of the USGS Modular groundwater flow model for aquifermanagement modeling has been developed. Aquifermanagement techniques integrate groundwater flow modeling with linear quadratic optimization methods for the solution of various aquifer management problems. The model AQMAN3D, is a modified version of a previously developed two-dimensional AQMAN model. The idea of coupling the AQMAN model with the MODULAR model arose because actual groundwater flow systems behave in a three dimensional manner, therefore requiring treatment as such, and due to the widespread use of MODULAR. The use of the AQMAN3D model permits the implementation of the technique known as aquifer managementmodeling. A generalized approach to obtain an optimal solution to an aquifer management problem is proposed, and a sample test problem is presented to illustrate the use of the model. Even though the model provides the hydrologist with a new and powerful investigative tool, its applicability is limited to confined or quasiconfined systems.

  8. Hydrogeophysical characterization and 3D modeling of heterogeneous unsaturated zone of a sandstone quarry

    NASA Astrophysics Data System (ADS)

    Winiarski, T.; Angulo-Jaramillo, R.; Goutaland, D.; Bievre, G.; Thevenin, L.; Sevestre, J.; Lassabatère, L.; Perrodin, Y.

    2008-12-01

    The potentially polluted sediments of the French ports, obtained by dredging maintenance operations, have to be disposed by filling-up open quarries why discontinuities can potentially lead to preferential flow. Indeed, flow anisotropy can be created either by: the original quarry structural discontinuities (faults, joints), the material sedimentary bedding or some anthropogenic effect (i.e., cracking induced by the operation of the quarry). The objective of the study is to estimate the role of the quarry heterogeneity on the unsaturated- zone water flow. A conceptual model based on the 3D structural recognition is proposed to study water flow. It is based on the recognition of the 3D geometric structure by using: (1) sedimentary structural geology principles, (2) geophysical measurements (Ground-Penetrating Radar and seismic refraction) performed on a limited but representative zone of the quarry and (3) in-situ Beerkan infiltration tests for soil hydraulic characterization. This new approach has been tested on a small volume (45m x 30m x 8m) of a Cenomanian sandstone quarry on southern France. The hydrogeophysical approach makes it possible to account for stratigraphic discontinuity non visible from the soil surface. GPR resolution is appropriate to resolve the sedimentary structure (direction, dip and bedding density). The seismic refraction completes the analysis by the water table localization. Both capillary retention and hydraulic conductivity curves have been obtained for uniform geometric elements using the BEST algorithm (Beerkan estimation of soil transfer parameters). The resolution of the Richards equation with 3D COMSOL Multiphysics software seems to emphasize the fractures role according to the sandstone initial conditions. Coupling geophysical and hydrodynamic approaches makes it possible to obtain a 3D in-situ realistic block representative of the studied site. Flow modeling on this block makes it possible to evaluate the risk at the quarry scale.

  9. Geomorphological maps and 3d models in cave research

    NASA Astrophysics Data System (ADS)

    Ballesteros, Daniel; Jiménez-Sánchez, Montserrat; José Domínguez-Cuesta, María

    2013-04-01

    Cave geomorphological processes and features can be studied by geomorphological maps although topographic maps, aerial photos and GPS are not available. Methods in cave geomorphological mapping are conditioned by cave environment configuration, the need of using speleological techniques, and limitations arising from the projection of the 3D data from the cave to a 2D plan. Some of our previous works in the Cantabrian Mountains and Cantabrian Coast (NW Spain) established the approach of the design of cave geomorphological maps and its legend. Today we are improving the display of cave process combining geomorphological maps and 3d models based on the experience obtained from the research of one cave from the Cantabrian Coast and four caves in the Picos de Europa National Park (funded by GEOCAVE project, Spanish National Parks Agency). The five caves are developed in Carboniferous limestone affected by faults and thrusts. The method of work includes: 1) the elaboration of the cave survey at 1:50 to 1:500 scale; 2) the check of the cave survey of three caves by closed loops; 3) the mapping of cave features based on the performed survey; 4) the 3d modeling of the caves approximating each survey shoot by an octagonal prism; and 5) the implementation and management of the survey and geomorphological map in a Geographic Information System. Based on the survey, the cavities are small caves to deep alpine shafts with 281 to 4,438 m length and up to 738 m deep. The precision of the cave maps only could be estimated in two caves at a cavity scale, displaying both of them a 2.49 % error. The prisms of the 3d model was classified into four groups according to the morphology of the cave passage: 1) canyons, 2) phreatic and epiphreatic tubes, 3) soutirage conduits, 4) mixed forms composed by phreatic and epiphreatic tubes modified by fluvial incision, 5) pitches and 6) irregular passages enlarged strongly by gravity process. According to our previous works geomorphological

  10. Geographic Video 3d Data Model And Retrieval

    NASA Astrophysics Data System (ADS)

    Han, Z.; Cui, C.; Kong, Y.; Wu, H.

    2014-04-01

    Geographic video includes both spatial and temporal geographic features acquired through ground-based or non-ground-based cameras. With the popularity of video capture devices such as smartphones, the volume of user-generated geographic video clips has grown significantly and the trend of this growth is quickly accelerating. Such a massive and increasing volume poses a major challenge to efficient video management and query. Most of the today's video management and query techniques are based on signal level content extraction. They are not able to fully utilize the geographic information of the videos. This paper aimed to introduce a geographic video 3D data model based on spatial information. The main idea of the model is to utilize the location, trajectory and azimuth information acquired by sensors such as GPS receivers and 3D electronic compasses in conjunction with video contents. The raw spatial information is synthesized to point, line, polygon and solid according to the camcorder parameters such as focal length and angle of view. With the video segment and video frame, we defined the three categories geometry object using the geometry model of OGC Simple Features Specification for SQL. We can query video through computing the spatial relation between query objects and three categories geometry object such as VFLocation, VSTrajectory, VSFOView and VFFovCone etc. We designed the query methods using the structured query language (SQL) in detail. The experiment indicate that the model is a multiple objective, integration, loosely coupled, flexible and extensible data model for the management of geographic stereo video.

  11. Modeling tree crown dynamics with 3D partial differential equations

    PubMed Central

    Beyer, Robert; Letort, Véronique; Cournède, Paul-Henry

    2014-01-01

    We characterize a tree's spatial foliage distribution by the local leaf area density. Considering this spatially continuous variable allows to describe the spatiotemporal evolution of the tree crown by means of 3D partial differential equations. These offer a framework to rigorously take locally and adaptively acting effects into account, notably the growth toward light. Biomass production through photosynthesis and the allocation to foliage and wood are readily included in this model framework. The system of equations stands out due to its inherent dynamic property of self-organization and spontaneous adaptation, generating complex behavior from even only a few parameters. The density-based approach yields spatially structured tree crowns without relying on detailed geometry. We present the methodological fundamentals of such a modeling approach and discuss further prospects and applications. PMID:25101095

  12. Measurement of Laser Weld Temperatures for 3D Model Input

    SciTech Connect

    Dagel, Daryl; Grossetete, Grant; Maccallum, Danny O.

    2016-10-01

    Laser welding is a key joining process used extensively in the manufacture and assembly of critical components for several weapons systems. Sandia National Laboratories advances the understanding of the laser welding process through coupled experimentation and modeling. This report summarizes the experimental portion of the research program, which focused on measuring temperatures and thermal history of laser welds on steel plates. To increase confidence in measurement accuracy, researchers utilized multiple complementary techniques to acquire temperatures during laser welding. This data serves as input to and validation of 3D laser welding models aimed at predicting microstructure and the formation of defects and their impact on weld-joint reliability, a crucial step in rapid prototyping of weapons components.

  13. 3D Tissue-Engineered Model of Ewing Sarcoma

    PubMed Central

    Lamhamedi-Cherradi, Salah-Eddine; Santoro, Marco; Ramammoorthy, Vandhana; Menegaz, Brian A.; Bartholomeusz, Geoffrey; Iles, Lakesla R.; Amin, Hesham M.; Livingston, Andrew J.; Mikos, Antonios G.; Ludwig, Joseph A.

    2015-01-01

    Despite longstanding reliance upon monolayer culture for studying cancer cells, and numerous advantages from both a practical and experimental standpoint, a growing body of evidence suggests more complex three-dimensional (3D) models are necessary to properly mimic many of the critical hallmarks associated with the oncogenesis, maintenance and spread of Ewing sarcoma (ES), the second most common pediatric bone tumor. And as clinicians increasingly turn to biologically-targeted therapies that exert their effects not only on the tumor cells themselves, but also on the surrounding extracellular matrix, it is especially important that preclinical models evolve in parallel to reliably measure antineoplastic effects and possible mechanisms of de novo and acquired drug resistance. Herein, we highlight a number of innovative methods used to fabricate biomimetic ES tumors, encompassing both the surrounding cellular milieu and extracellular matrix (ECM), and suggest potential applications to advance our understanding of ES biology, preclinical drug testing, and personalized medicine. PMID:25109853

  14. 3D Model of the Eta Carinae Little Homunculus Nebula

    NASA Astrophysics Data System (ADS)

    Steffen, Wolfgang; Teodoro, Mairan; Madura, Thomas; Groh, Jose H.; Gull, Theodore R.; Corcoran, Michael F.; Damineli, Augusto; Hamaguchi, Kenji

    2015-01-01

    We extend our morpho-kinematic 3D modeling of the Homunculus nebula (Steffen et al., 2014) to the interior nested Little Homunculus. The model is based on spectroscopic observations from HST/STIS. We find that the structure of the interior Little Homunculus is rather flat in the polar regions and interacts with the main Homunculus nebula only on one side, towards the periastron direction of the binary orbit. Furthermore, the two lobes of the LH are misaligned, also towards the periastron direction. As an explanation for the misalignment we propose that, in both cases, shortly after the eruptions that created the bipolar nebulae from the primary star, the off-center wind of the secondary has pushed the ejecta towards the periastron directions, since the secondary is most of the time near the apastron. Future hydrodynamic simulations are warranted to confirm this scenario.

  15. Plasticized protein for 3D printing by fused deposition modeling

    NASA Astrophysics Data System (ADS)

    Chaunier, Laurent; Leroy, Eric; Della Valle, Guy; Lourdin, Denis

    2016-10-01

    The developments of Additive Manufacturing (AM) by Fused Deposition Modeling (FDM) now target new 3D printable materials, leading to novel properties like those given by biopolymers such as proteins: degradability, biocompatibility and edibility. Plasticized materials from zein, a storage protein issued from corn, present interesting thermomechanical and rheological properties, possibly matching with AM-FDM specifications. Thus commercial zein plasticized with 20% glycerol has a glass transition temperature (Tg) at about 42°C, after storage at intermediate relative humidity (RH=59%). Its principal mechanical relaxation at Tα ≈ 50°C leads to a drop of the elastic modulus from about 1.1 GPa, at ambient temperature, to 0.6 MPa at Tα+100°C. These values are in the same range as values obtained in the case of standard polymers for AM-FDM processing, as PLA and ABS, although relaxation mechanisms are likely different in these materials. Such results lead to the setting up of zein-based compositions printable by AM-FDM and allow processing bioresorbable printed parts, with designed 3D geometry and structure.

  16. Gene3D: modelling protein structure, function and evolution.

    PubMed

    Yeats, Corin; Maibaum, Michael; Marsden, Russell; Dibley, Mark; Lee, David; Addou, Sarah; Orengo, Christine A

    2006-01-01

    The Gene3D release 4 database and web portal (http://cathwww.biochem.ucl.ac.uk:8080/Gene3D) provide a combined structural, functional and evolutionary view of the protein world. It is focussed on providing structural annotation for protein sequences without structural representatives--including the complete proteome sets of over 240 different species. The protein sequences have also been clustered into whole-chain families so as to aid functional prediction. The structural annotation is generated using HMM models based on the CATH domain families; CATH is a repository for manually deduced protein domains. Amongst the changes from the last publication are: the addition of over 100 genomes and the UniProt sequence database, domain data from Pfam, metabolic pathway and functional data from COGs, KEGG and GO, and protein-protein interaction data from MINT and BIND. The website has been rebuilt to allow more sophisticated querying and the data returned is presented in a clearer format with greater functionality. Furthermore, all data can be downloaded in a simple XML format, allowing users to carry out complex investigations at their own computers.

  17. 3D in vitro modeling of the central nervous system

    PubMed Central

    Hopkins, Amy M.; DeSimone, Elise; Chwalek, Karolina; Kaplan, David L.

    2015-01-01

    There are currently more than 600 diseases characterized as affecting the central nervous system (CNS) which inflict neural damage. Unfortunately, few of these conditions have effective treatments available. Although significant efforts have been put into developing new therapeutics, drugs which were promising in the developmental phase have high attrition rates in late stage clinical trials. These failures could be circumvented if current 2D in vitro and in vivo models were improved. 3D, tissue-engineered in vitro systems can address this need and enhance clinical translation through two approaches: (1) bottom-up, and (2) top-down (developmental/regenerative) strategies to reproduce the structure and function of human tissues. Critical challenges remain including biomaterials capable of matching the mechanical properties and extracellular matrix (ECM) composition of neural tissues, compartmentalized scaffolds that support heterogeneous tissue architectures reflective of brain organization and structure, and robust functional assays for in vitro tissue validation. The unique design parameters defined by the complex physiology of the CNS for construction and validation of 3D in vitro neural systems are reviewed here. PMID:25461688

  18. 3D in vitro modeling of the central nervous system.

    PubMed

    Hopkins, Amy M; DeSimone, Elise; Chwalek, Karolina; Kaplan, David L

    2015-02-01

    There are currently more than 600 diseases characterized as affecting the central nervous system (CNS) which inflict neural damage. Unfortunately, few of these conditions have effective treatments available. Although significant efforts have been put into developing new therapeutics, drugs which were promising in the developmental phase have high attrition rates in late stage clinical trials. These failures could be circumvented if current 2D in vitro and in vivo models were improved. 3D, tissue-engineered in vitro systems can address this need and enhance clinical translation through two approaches: (1) bottom-up, and (2) top-down (developmental/regenerative) strategies to reproduce the structure and function of human tissues. Critical challenges remain including biomaterials capable of matching the mechanical properties and extracellular matrix (ECM) composition of neural tissues, compartmentalized scaffolds that support heterogeneous tissue architectures reflective of brain organization and structure, and robust functional assays for in vitro tissue validation. The unique design parameters defined by the complex physiology of the CNS for construction and validation of 3D in vitro neural systems are reviewed here.

  19. Modeling approaches for ligand-based 3D similarity.

    PubMed

    Tresadern, Gary; Bemporad, Daniele

    2010-10-01

    3D ligand-based similarity approaches are widely used in the early phases of drug discovery for tasks such as hit finding by virtual screening or compound design with quantitative structure-activity relationships. Here in we review widely used software for performing such tasks. Some techniques are based on relatively mature technology, shape-based similarity for instance. Typically, these methods remained in the realm of the expert user, the experienced modeler. However, advances in implementation and speed have improved usability and allow these methods to be applied to databases comprising millions of compounds. There are now many reports of such methods impacting drug-discovery projects. As such, the medicinal chemistry community has become the intended market for some of these new tools, yet they may consider the wide array and choice of approaches somewhat disconcerting. Each method has subtle differences and is better suited to certain tasks than others. In this article we review some of the widely used computational methods via application, provide straightforward background on the underlying theory and provide examples for the interested reader to pursue in more detail. In the new era of preclinical drug discovery there will be ever more pressure to move faster and more efficiently, and computational approaches based on 3D ligand similarity will play an increasing role in in this process.

  20. Recovering Old Stereoscopic Negatives and Producing Digital 3d Models of Former Appearances of Historic Buildings

    NASA Astrophysics Data System (ADS)

    Rodríguez Miranda, Á.; Valle Melón, J. M.

    2017-02-01

    Three-dimensional models with photographic textures have become a usual product for the study and dissemination of elements of heritage. The interest for cultural heritage also includes evolution along time; therefore, apart from the 3D models of the current state, it is interesting to be able to generate models representing how they were in the past. To that end, it is necessary to resort to archive information corresponding to the moments that we want to visualize. This text analyses the possibilities of generating 3D models of surfaces with photographic textures from old collections of analog negatives coming from works of terrestrial stereoscopic photogrammetry of historic buildings. The case studies presented refer to the geometric documentation of a small hermitage (done in 1996) and two sections of a wall (year 2000). The procedure starts with the digitization of the film negatives and the processing of the images generated, after which a combination of different methods for 3D reconstruction and texture wrapping are applied: techniques working simultaneously with several images (such as the algorithms of Structure from Motion - SfM) and single image techniques (such as the reconstruction based on vanishing points). Then, the features of the obtained models are described according to the geometric accuracy, completeness and aesthetic quality. In this way, it is possible to establish the real applicability of the models in order to be useful for the aforementioned historical studies and dissemination purposes. The text also wants to draw attention to the importance of preserving the documentary heritage available in the collections of negatives in archival custody and to the increasing difficulty of using them due to: (1) problems of access and physical conservation, (2) obsolescence of the equipment for scanning and stereoplotting and (3) the fact that the software for processing digitized photographs is discontinued.

  1. Advanced prior modeling for 3D bright field electron tomography

    NASA Astrophysics Data System (ADS)

    Sreehari, Suhas; Venkatakrishnan, S. V.; Drummy, Lawrence F.; Simmons, Jeffrey P.; Bouman, Charles A.

    2015-03-01

    Many important imaging problems in material science involve reconstruction of images containing repetitive non-local structures. Model-based iterative reconstruction (MBIR) could in principle exploit such redundancies through the selection of a log prior probability term. However, in practice, determining such a log prior term that accounts for the similarity between distant structures in the image is quite challenging. Much progress has been made in the development of denoising algorithms like non-local means and BM3D, and these are known to successfully capture non-local redundancies in images. But the fact that these denoising operations are not explicitly formulated as cost functions makes it unclear as to how to incorporate them in the MBIR framework. In this paper, we formulate a solution to bright field electron tomography by augmenting the existing bright field MBIR method to incorporate any non-local denoising operator as a prior model. We accomplish this using a framework we call plug-and-play priors that decouples the log likelihood and the log prior probability terms in the MBIR cost function. We specifically use 3D non-local means (NLM) as the prior model in the plug-and-play framework, and showcase high quality tomographic reconstructions of a simulated aluminum spheres dataset, and two real datasets of aluminum spheres and ferritin structures. We observe that streak and smear artifacts are visibly suppressed, and that edges are preserved. Also, we report lower RMSE values compared to the conventional MBIR reconstruction using qGGMRF as the prior model.

  2. Brandenburg 3D - a comprehensive 3D Subsurface Model, Conception of an Infrastructure Node and a Web Application

    NASA Astrophysics Data System (ADS)

    Kerschke, Dorit; Schilling, Maik; Simon, Andreas; Wächter, Joachim

    2014-05-01

    The Energiewende and the increasing scarcity of raw materials will lead to an intensified utilization of the subsurface in Germany. Within this context, geological 3D modeling is a fundamental approach for integrated decision and planning processes. Initiated by the development of the European Geospatial Infrastructure INSPIRE, the German State Geological Offices started digitizing their predominantly analog archive inventory. Until now, a comprehensive 3D subsurface model of Brandenburg did not exist. Therefore the project B3D strived to develop a new 3D model as well as a subsequent infrastructure node to integrate all geological and spatial data within the Geodaten-Infrastruktur Brandenburg (Geospatial Infrastructure, GDI-BB) and provide it to the public through an interactive 2D/3D web application. The functionality of the web application is based on a client-server architecture. Server-sided, all available spatial data is published through GeoServer. GeoServer is designed for interoperability and acts as the reference implementation of the Open Geospatial Consortium (OGC) Web Feature Service (WFS) standard that provides the interface that allows requests for geographical features. In addition, GeoServer implements, among others, the high performance certified compliant Web Map Service (WMS) that serves geo-referenced map images. For publishing 3D data, the OGC Web 3D Service (W3DS), a portrayal service for three-dimensional geo-data, is used. The W3DS displays elements representing the geometry, appearance, and behavior of geographic objects. On the client side, the web application is solely based on Free and Open Source Software and leans on the JavaScript API WebGL that allows the interactive rendering of 2D and 3D graphics by means of GPU accelerated usage of physics and image processing as part of the web page canvas without the use of plug-ins. WebGL is supported by most web browsers (e.g., Google Chrome, Mozilla Firefox, Safari, and Opera). The web

  3. Faceless identification: a model for person identification using the 3D shape and 3D motion as cues

    NASA Astrophysics Data System (ADS)

    Klasen, Lena M.; Li, Haibo

    1999-02-01

    Person identification by using biometric methods based on image sequences, or still images, often requires a controllable and cooperative environment during the image capturing stage. In the forensic case the situation is more likely to be the opposite. In this work we propose a method that makes use of the anthropometry of the human body and human actions as cues for identification. Image sequences from surveillance systems are used, which can be seen as monocular image sequences. A 3D deformable wireframe body model is used as a platform to handle the non-rigid information of the 3D shape and 3D motion of the human body from the image sequence. A recursive method for estimating global motion and local shape variations is presented, using two recursive feedback systems.

  4. Multiscale Interactions in a 3D Model of the Contracting Ventricle.

    PubMed

    Amar, Ani; Zlochiver, Sharon; Barnea, Ofer

    2015-12-01

    A biophysical detailed multiscale model of the myocardium is presented. The model was used to study the contribution of interrelated cellular mechanisms to global myocardial function. The multiscale model integrates cellular electrophysiology, excitation propagation dynamics and force development models into a geometrical fiber based model of the ventricle. The description of the cellular electrophysiology in this study was based on the Ten Tusscher-Noble-Noble-Panfilov heterogeneous model for human ventricular myocytes. A four-state model of the sarcomeric control of contraction developed by Negroni and Lascano was employed to model the intracellular mechanism of force generation. The propagation of electrical excitation was described by a reaction-diffusion equation. The 3D geometrical model of the ventricle, based on single fiber contraction was used as a platform for the evaluation of proposed models. The model represents the myocardium as an anatomically oriented array of contracting fibers with individual fiber parameters such as size, spatial location, orientation and mechanical properties. Moreover, the contracting ventricle model interacts with intraventricular blood elements linking the contractile elements to the heart's preload and afterload, thereby producing the corresponding pressure-volume loop. The results show that the multiscale ventricle model is capable of simulating mechanical contraction, pressure generation and load interactions as well as demonstrating the individual contribution of each ion current.

  5. The USGS 3D Seismic Velocity Model for Northern California

    NASA Astrophysics Data System (ADS)

    Brocher, T. M.; Aagaard, B.; Simpson, R. W.; Jachens, R. C.

    2006-12-01

    We present a new regional 3D seismic velocity model for Northern California for use in strong motion simulations of the 1906 San Francisco and other earthquakes. The model includes compressional-wave velocity (Vp), shear-wave velocity (Vs), density, and intrinsic attenuation (Qp, Qs). These properties were assigned for each rock type in a 3D geologic model derived from surface outcrops, boreholes, gravity and magnetic data, and seismic reflection, refraction, and tomography studies. A detailed description of the model, USGS Bay Area Velocity Model 05.1.0, is available online [http://www.sf06simulation.org/geology/velocitymodel]. For ground motion simulations Vs and Qs are more important parameters than Vp and Qp because the strongest ground motions are generated chiefly by shear and surface wave arrivals. Because Vp data are more common than Vs data, however, we first developed Vp versus depth relations for each rock type and then converted these to Vs versus depth relations. For the most important rock types in Northern California we compiled measurements of Vp versus depth using borehole logs, laboratory measurements on hand samples, seismic refraction profiles, and tomography models. These rock types include Salinian and Sierran granitic rocks, metagraywackes and greenstones of the Franciscan Complex, Tertiary and Mesozoic sedimentary and volcanic rocks, and Quaternary and Holocene deposits (Brocher, USGS OFR 05-1317, 2005). Vp versus depth curves were converted to Vs versus depth curves using new empirical nonlinear relations between Vs and Vp (Brocher, BSSA, 2005). These relations, showing that Poisson's ratio is a nonlinear function of Vp, were similarly based on compilations of diverse Vs and Vp measurements on a large suite of rock types, mainly from California and the Pacific Northwest. The model is distributed in a discretized form with routines to query the model using C++, C, and Fortran 77 programming languages. The geologic model was discretized at

  6. A 3D Bubble Merger Model for RTI Mixing

    NASA Astrophysics Data System (ADS)

    Cheng, Baolian

    2015-11-01

    In this work we present a model for the merger processes of bubbles at the edge of an unstable acceleration driven mixing layer. Steady acceleration defines a self-similar mixing process, with a time-dependent inverse cascade of structures of increasing size. The time evolution is itself a renormalization group evolution. The model predicts the growth rate of a Rayleigh-Taylor chaotic fluid-mixing layer. The 3-D model differs from the 2-D merger model in several important ways. Beyond the extension of the model to three dimensions, the model contains one phenomenological parameter, the variance of the bubble radii at fixed time. The model also predicts several experimental numbers: the bubble mixing rate, the mean bubble radius, and the bubble height separation at the time of merger. From these we also obtain the bubble height to the radius aspect ratio, which is in good agreement with experiments. Applications to recent NIF and Omega experiments will be discussed. This work was performed under the auspices of the U.S. Department of Energy by the Los Alamos National Laboratory under Contract No. W-7405-ENG-36.

  7. Handheld camera 3D modeling system using multiple reference panels

    NASA Astrophysics Data System (ADS)

    Fujimura, Kouta; Oue, Yasuhiro; Terauchi, Tomoya; Emi, Tetsuichi

    2002-03-01

    A novel 3D modeling system in which a target object is easily captured and modeled by using a hand-held camera with several reference panels is presented in this paper. The reference panels are designed to be able to obtain the camera position and discriminate between each other. A conventional 3D modeling system using a reference panel has several restrictions regarding the target object, specifically the size and its location. Our system uses multiple reference panels, which are set around the target object to remove these restrictions. The main features of this system are as follows: 1) The whole shape and photo-realistic textures of the target object can be digitized based on several still images or a movie captured by using a hand-held camera; as well as each location of the camera that can be calculated using the reference panels. 2) Our system can be provided as a software product only. That means there are no special requirements for hardware; even the reference panels , because they can be printed from image files or software. 3) This system can be applied to digitize a larger object. In the experiments, we developed and used an interactive region selection tool to detect the silhouette on each image instead of using the chroma -keying method. We have tested our system with a toy object. The calculation time is about 10 minutes (except for the capturing the images and extracting the silhouette by using our tool) on a personal computer with a Pentium-III processor (600MHz) and 320MB memory. However, it depends on how complex the images are and how many images you use. Our future plan is to evaluate the system with various kind of objects, specifically, large ones in outdoor environments.

  8. 3-D numerical modeling of plume-induced subduction initiation

    NASA Astrophysics Data System (ADS)

    Baes, Marzieh; Gerya, taras; Sobolev, Stephan

    2016-04-01

    Investigation of mechanisms involved in formation of a new subduction zone can help us to better understand plate tectonics. Despite numerous previous studies, it is still unclear how and where an old oceanic plate starts to subduct beneath the other plate. One of the proposed scenarios for nucleation of subduction is plume-induced subduction initiation, which was investigated in detail, using 2-D models, by Ueda et al. (2008). Recently. Gerya et al. (2015), using 3D numerical models, proposed that plume-lithosphere interaction in the Archean led to the subduction initiation and onset of plate tectonic. In this study, we aim to pursue work of Ueda et al. (2008) by incorporation of 3-D thermo-mechanical models to investigate conditions leading to oceanic subduction initiation as a result of thermal-chemical mantle plume-lithosphere interaction in the modern earth. Results of our experiments show four different deformation regimes in response to plume-lithosphere interaction, that are a) self-sustaining subduction initiation where subduction becomes self-sustained, b) freezing subduction initiation where subduction stops at shallow depths, c) slab break-off where subducting circular slab breaks off soon after formation and d) plume underplating where plume does not pass through the lithosphere but spreads beneath it (failed subduction initiation). These different regimes depend on several parameters such as plume's size, composition and temperature, lithospheric brittle/plastic strength, age of the oceanic lithosphere and presence/absence of lithospheric heterogeneities. Results show that subduction initiates and becomes self-sustained when lithosphere is older than 10 Myr and non-dimensional ratio of the plume buoyancy force and lithospheric strength above the plume is higher than 2.

  9. 3D model generation using an airborne swarm

    NASA Astrophysics Data System (ADS)

    Clark, R. A.; Punzo, G.; Dobie, G.; MacLeod, C. N.; Summan, R.; Pierce, G.; Macdonald, M.; Bolton, G.

    2015-03-01

    Using an artificial kinematic field to provide co-ordination between multiple inspection UAVs, the authors herein demonstrate full 3D modelling capability based on a photogrammetric system. The operation of the system is demonstrated by generating a full 3D surface model of an intermediate level nuclear waste storage drum. Such drums require periodic inspection to ensure that drum distortion or corrosion is carefully monitored. Performing this inspection with multiple airborne platforms enables rapid inspection of structures that are inaccessible to on-surface remote vehicles and are in human-hazardous environments. A three-dimensional surface-meshed model of the target can then be constructed in post-processing through photogrammetry analysis of the visual inspection data. The inspection environment uses a tracking system to precisely monitor the position of each aerial vehicle within the enclosure. The vehicles used are commercially available Parrot AR. Drone quadcopters, controlled through a computer interface connected over an IEEE 802.11n (WiFi) network, implementing a distributed controller for each vehicle. This enables the autonomous and distributed elements of the control scheme to be retained, while alleviating the vehicles of the control algorithm's computational load. The control scheme relies on a kinematic field defined with the target at its centre. This field defines the trajectory for all the drones in the volume relative to the central target, enabling the drones to circle the target at a set radius while avoiding drone collisions. This function enables complete coverage along the height of the object, which is assured by transitioning to another inspection band only after completing circumferential coverage. Using a swarm of vehicles, the time until complete coverage can be significantly reduced.

  10. 3D model generation using an airborne swarm

    SciTech Connect

    Clark, R. A.; Punzo, G.; Macdonald, M.; Dobie, G.; MacLeod, C. N.; Summan, R.; Pierce, G.; Bolton, G.

    2015-03-31

    Using an artificial kinematic field to provide co-ordination between multiple inspection UAVs, the authors herein demonstrate full 3D modelling capability based on a photogrammetric system. The operation of the system is demonstrated by generating a full 3D surface model of an intermediate level nuclear waste storage drum. Such drums require periodic inspection to ensure that drum distortion or corrosion is carefully monitored. Performing this inspection with multiple airborne platforms enables rapid inspection of structures that are inaccessible to on-surface remote vehicles and are in human-hazardous environments. A three-dimensional surface-meshed model of the target can then be constructed in post-processing through photogrammetry analysis of the visual inspection data. The inspection environment uses a tracking system to precisely monitor the position of each aerial vehicle within the enclosure. The vehicles used are commercially available Parrot AR. Drone quadcopters, controlled through a computer interface connected over an IEEE 802.11n (WiFi) network, implementing a distributed controller for each vehicle. This enables the autonomous and distributed elements of the control scheme to be retained, while alleviating the vehicles of the control algorithm’s computational load. The control scheme relies on a kinematic field defined with the target at its centre. This field defines the trajectory for all the drones in the volume relative to the central target, enabling the drones to circle the target at a set radius while avoiding drone collisions. This function enables complete coverage along the height of the object, which is assured by transitioning to another inspection band only after completing circumferential coverage. Using a swarm of vehicles, the time until complete coverage can be significantly reduced.

  11. Crashworthiness analysis using advanced material models in DYNA3D

    SciTech Connect

    Logan, R.W.; Burger, M.J.; McMichael, L.D.; Parkinson, R.D.

    1993-10-22

    As part of an electric vehicle consortium, LLNL and Kaiser Aluminum are conducting experimental and numerical studies on crashworthy aluminum spaceframe designs. They have jointly explored the effect of heat treat on crush behavior and duplicated the experimental behavior with finite-element simulations. The major technical contributions to the state of the art in numerical simulation arise from the development and use of advanced material model descriptions for LLNL`s DYNA3D code. Constitutive model enhancements in both flow and failure have been employed for conventional materials such as low-carbon steels, and also for lighter weight materials such as aluminum and fiber composites being considered for future vehicles. The constitutive model enhancements are developed as extensions from LLNL`s work in anisotropic flow and multiaxial failure modeling. Analysis quality as a function of level of simplification of material behavior and mesh is explored, as well as the penalty in computation cost that must be paid for using more complex models and meshes. The lightweight material modeling technology is being used at the vehicle component level to explore the safety implications of small neighborhood electric vehicles manufactured almost exclusively from these materials.

  12. Energy flow in passive and active 3D cochlear model

    SciTech Connect

    Wang, Yanli; Steele, Charles; Puria, Sunil

    2015-12-31

    Energy flow in the cochlea is an important characteristic of the cochlear traveling wave, and many investigators, such as von Békésy and Lighthill, have discussed this phenomenon. Particularly after the discovery of the motility of the outer hair cells (OHCs), the nature of the power gain of the cochlea has been a fundamental research question. In the present work, direct three-dimensional (3D) calculations of the power on cross sections of the cochlea and on the basilar membrane are performed based on a box model of the mouse cochlea. The distributions of the fluid pressure and fluid velocity in the scala vestibuli are presented. The power output from the OHCs and the power loss due to fluid viscous damping are calculated along the length of the cochlea. This work provides a basis for theoretical calculations of the power gain of the OHCs from mechanical considerations.

  13. Energy flow in passive and active 3D cochlear model

    NASA Astrophysics Data System (ADS)

    Wang, Yanli; Puria, Sunil; Steele, Charles

    2015-12-01

    Energy flow in the cochlea is an important characteristic of the cochlear traveling wave, and many investigators, such as von Békésy and Lighthill, have discussed this phenomenon. Particularly after the discovery of the motility of the outer hair cells (OHCs), the nature of the power gain of the cochlea has been a fundamental research question. In the present work, direct three-dimensional (3D) calculations of the power on cross sections of the cochlea and on the basilar membrane are performed based on a box model of the mouse cochlea. The distributions of the fluid pressure and fluid velocity in the scala vestibuli are presented. The power output from the OHCs and the power loss due to fluid viscous damping are calculated along the length of the cochlea. This work provides a basis for theoretical calculations of the power gain of the OHCs from mechanical considerations.

  14. Appearance-based color face recognition with 3D model

    NASA Astrophysics Data System (ADS)

    Wang, Chengzhang; Bai, Xiaoming

    2013-03-01

    Appearance-based face recognition approaches explore color cues of face images, i.e. grey or color information for recognition task. They first encode color face images, and then extract facial features for classification. Similar to conventional singular value decomposition, hypercomplex matrix also exists singular value decomposition on hypercomplex field. In this paper, a novel color face recognition approach based on hypercomplex singular value decomposition is proposed. The approach employs hypercomplex to encode color face information of different channels simultaneously. Hypercomplex singular value decomposition is utilized then to compute the basis vectors of the color face subspace. To improve learning efficiency of the algorithm, 3D active deformable model is exploited to generate virtual face images. Color face samples are projected onto the subspace and projection coefficients are utilized as facial features. Experimental results on CMU PIE face database verify the effectiveness of the proposed approach.

  15. 3D Model of the San Emidio Geothermal Area

    DOE Data Explorer

    James E. Faulds

    2013-12-31

    The San Emidio geothermal system is characterized by a left-step in a west-dipping normal fault system that bounds the western side of the Lake Range. The 3D geologic model consists of 5 geologic units and 55 faults. Overlying Jurrassic-Triassic metasedimentary basement is a ~500 m-1000 m thick section of the Miocene lower Pyramid sequence, pre- syn-extensional Quaternary sedimentary rocks and post-extensional Quaternary rocks. 15-30º eastward dip of the stratigraphy is controlled by the predominant west-dipping fault set. Both geothermal production and injection are concentrated north of the step over in an area of closely spaced west dipping normal faults.

  16. 3D Model of the Neal Hot Springs Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    The Neal Hot Springs geothermal system lies in a left-step in a north-striking, west-dipping normal fault system, consisting of the Neal Fault to the south and the Sugarloaf Butte Fault to the north (Edwards, 2013). The Neal Hot Springs 3D geologic model consists of 104 faults and 13 stratigraphic units. The stratigraphy is sub-horizontal to dipping <10 degrees and there is no predominant dip-direction. Geothermal production is exclusively from the Neal Fault south of, and within the step-over, while geothermal injection is into both the Neal Fault to the south of the step-over and faults within the step-over.

  17. 3D model atmospheres and the solar photospheric oxygen abundance

    NASA Astrophysics Data System (ADS)

    Caffau, E.; Ludwig, H.-G.

    2008-10-01

    In recent years the photospheric solar oxygen abundance experienced a significant downward revision. However, a low photospheric abundance is incompatible with the value in the solar interior inferred from helioseismology. For contributing to the dispute whether the solar oxygen abundance is “high” or “low”, we re-derived its photospheric abundance independently of previous analyses. We applied 3D (CO5BOLD) as well as 1D model atmospheres. We considered standard disc-centre and disc-integrated spectral atlases, as well as newly acquired solar intensity spectra at different heliocentric angles. We determined the oxygen abundances from equivalent width and/or line profile fitting of a number of atomic lines. As preliminary result, we find an oxygen abundance in the range 8.73 8.79, encompassing the value obtained by Holweger (2001), and somewhat higher than the value obtained by Asplund et al. (2005).

  18. Towards Automatic Semantic Labelling of 3D City Models

    NASA Astrophysics Data System (ADS)

    Rook, M.; Biljecki, F.; Diakité, A. A.

    2016-10-01

    The lack of semantic information in many 3D city models is a considerable limiting factor in their use, as a lot of applications rely on semantics. Such information is not always available, since it is not collected at all times, it might be lost due to data transformation, or its lack may be caused by non-interoperability in data integration from other sources. This research is a first step in creating an automatic workflow that semantically labels plain 3D city model represented by a soup of polygons, with semantic and thematic information, as defined in the CityGML standard. The first step involves the reconstruction of the topology, which is used in a region growing algorithm that clusters upward facing adjacent triangles. Heuristic rules, embedded in a decision tree, are used to compute a likeliness score for these regions that either represent the ground (terrain) or a RoofSurface. Regions with a high likeliness score, to one of the two classes, are used to create a decision space, which is used in a support vector machine (SVM). Next, topological relations are utilised to select seeds that function as a start in a region growing algorithm, to create regions of triangles of other semantic classes. The topological relationships of the regions are used in the aggregation of the thematic building features. Finally, the level of detail is detected to generate the correct output in CityGML. The results show an accuracy between 85 % and 99 % in the automatic semantic labelling on four different test datasets. The paper is concluded by indicating problems and difficulties implying the next steps in the research.

  19. 3D Model of the Tuscarora Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    The Tuscarora geothermal system sits within a ~15 km wide left-step in a major west-dipping range-bounding normal fault system. The step over is defined by the Independence Mountains fault zone and the Bull Runs Mountains fault zone which overlap along strike. Strain is transferred between these major fault segments via and array of northerly striking normal faults with offsets of 10s to 100s of meters and strike lengths of less than 5 km. These faults within the step over are one to two orders of magnitude smaller than the range-bounding fault zones between which they reside. Faults within the broad step define an anticlinal accommodation zone wherein east-dipping faults mainly occupy western half of the accommodation zone and west-dipping faults lie in the eastern half of the accommodation zone. The 3D model of Tuscarora encompasses 70 small-offset normal faults that define the accommodation zone and a portion of the Independence Mountains fault zone, which dips beneath the geothermal field. The geothermal system resides in the axial part of the accommodation, straddling the two fault dip domains. The Tuscarora 3D geologic model consists of 10 stratigraphic units. Unconsolidated Quaternary alluvium has eroded down into bedrock units, the youngest and stratigraphically highest bedrock units are middle Miocene rhyolite and dacite flows regionally correlated with the Jarbidge Rhyolite and modeled with uniform cumulative thickness of ~350 m. Underlying these lava flows are Eocene volcanic rocks of the Big Cottonwood Canyon caldera. These units are modeled as intracaldera deposits, including domes, flows, and thick ash deposits that change in thickness and locally pinch out. The Paleozoic basement of consists metasedimenary and metavolcanic rocks, dominated by argillite, siltstone, limestone, quartzite, and metabasalt of the Schoonover and Snow Canyon Formations. Paleozoic formations are lumped in a single basement unit in the model. Fault blocks in the eastern

  20. A new 3D dynamical biomechanical tongue model

    NASA Astrophysics Data System (ADS)

    Gerard, Jean-Michel; Perrier, Pascal; Payan, Yohan; Wilhelms-Tricarico, Reiner

    2004-05-01

    A new dynamical biomechanical tongue model is being developed to study speech motor control. In spite of its computational complexity, a 3D representation was chosen in order to account for various contacts between tongue and external structures such as teeth, palate, and vocal tract walls. A fair representation of tongue muscle anatomy is provided, by designing the finite element mesh from the visible human data set (female subject). Model geometry was then matched to a human speaker, so that simulations can be quantitatively compared to experimental MRI data. A set of 11 muscles is modeled, whose role in speech gestures is well established. Each muscle is defined by a set of elements whose elastic properties change with muscle activation. Muscles forces are applied to the tongue model via macrofibers defined within the mesh by muscle specific sets of nodes. These forces are currently specified as step functions. Boundary conditions are set using zero-displacement nodes simulating attachments of tongue on bony structures. The nonlinear mechanical properties of tongue soft tissues are modeled using a hyperelastic material. Three-dimensional tongue deformations generated by each muscle, using FEM software ANSYS for computation, will be presented. Implications for speech motor control will be proposed.

  1. A new 3D dynamical biomechanical tongue model

    NASA Astrophysics Data System (ADS)

    Gerard, Jean-Michel; Perrier, Pascal; Payan, Yohan; Wilhelms-Tricarico, Reiner

    2001-05-01

    A new dynamical biomechanical tongue model is being developed to study speech motor control. In spite of its computational complexity, a 3D representation was chosen in order to account for various contacts between tongue and external structures such as teeth, palate, and vocal tract walls. A fair representation of tongue muscle anatomy is provided, by designing the finite element mesh from the visible human data set (female subject). Model geometry was then matched to a human speaker, so that simulations can be quantitatively compared to experimental MRI data. A set of 11 muscles is modeled, whose role in speech gestures is well established. Each muscle is defined by a set of elements whose elastic properties change with muscle activation. Muscles forces are applied to the tongue model via macrofibers defined within the mesh by muscle specific sets of nodes. These forces are currently specified as step functions. Boundary conditions are set using zero-displacement nodes simulating attachments of tongue on bony structures. The nonlinear mechanical properties of tongue soft tissues are modeled using a hyperelastic material. Three-dimensional tongue deformations generated by each muscle, using FEM software ANSYS for computation, will be presented. Implications for speech motor control will be proposed.

  2. 3D Printed Molecules and Extended Solid Models for Teaching Symmetry and Point Groups

    ERIC Educational Resources Information Center

    Scalfani, Vincent F.; Vaid, Thomas P.

    2014-01-01

    Tangible models help students and researchers visualize chemical structures in three dimensions (3D). 3D printing offers a unique and straightforward approach to fabricate plastic 3D models of molecules and extended solids. In this article, we prepared a series of digital 3D design files of molecular structures that will be useful for teaching…

  3. A Generalized Approach to the Modeling and Analysis of 3D Surface Morphology in Organisms

    PubMed Central

    Pappas, Janice L.; Miller, Daniel J.

    2013-01-01

    The surface geometry of an organism represents the boundary of its three-dimensional (3D) form and can be used as a proxy for the phenotype. A mathematical approach is presented that describes surface morphology using parametric 3D equations with variables expressed as x, y, z in terms of parameters u, v. Partial differentiation of variables with respect to parameters yields elements of the Jacobian representing tangent lines and planes of every point on the surface. Jacobian elements provide a compact size-free summary of the entire surface, and can be used as variables in principal components analysis to produce a morphospace. Mollusk and echinoid models are generated to demonstrate that whole organisms can be represented in a common morphospace, regardless of differences in size, geometry, and taxonomic affinity. Models can be used to simulate theoretical forms, novel morphologies, and patterns of phenotypic variation, and can also be empirically-based by designing them with reference to actual forms using reverse engineering principles. Although this study uses the Jacobian to summarize models, they can also be analyzed with 3D methods such as eigensurface, spherical harmonics, wavelet analysis, and geometric morphometrics. This general approach should prove useful for exploring broad questions regarding morphological evolution and variation. PMID:24204866

  4. Model-based adaptive 3D sonar reconstruction in reverberating environments.

    PubMed

    Saucan, Augustin-Alexandru; Sintes, Christophe; Chonavel, Thierry; Caillec, Jean-Marc Le

    2015-10-01

    In this paper, we propose a novel model-based approach for 3D underwater scene reconstruction, i.e., bathymetry, for side scan sonar arrays in complex and highly reverberating environments like shallow water areas. The presence of multipath echoes and volume reverberation generates false depth estimates. To improve the resulting bathymetry, this paper proposes and develops an adaptive filter, based on several original geometrical models. This multimodel approach makes it possible to track and separate the direction of arrival trajectories of multiple echoes impinging the array. Echo tracking is perceived as a model-based processing stage, incorporating prior information on the temporal evolution of echoes in order to reject cluttered observations generated by interfering echoes. The results of the proposed filter on simulated and real sonar data showcase the clutter-free and regularized bathymetric reconstruction. Model validation is carried out with goodness of fit tests, and demonstrates the importance of model-based processing for bathymetry reconstruction.

  5. A multipurpose 3-D grid of stellar models

    NASA Astrophysics Data System (ADS)

    Maíz Apellániz, J.

    2013-05-01

    The last two decades have produced a proliferation of stellar atmosphere grids, evolutionary tracks, and isochrones which are available to the astronomical community from different internet services. However, it is not straightforward (at least for an inexperienced user) to manipulate those models to answer questions of the type: What is the spectral energy distribution of a 9000 K giant? What about its J-band magnitude for different metallicities? What can I tell about the mass of a star if I know that its unreddened B-V color is -0.05 and its luminosity in solar units is 10^5? The answers to those questions are indeed in the models but a series of transformations and combinations involving different variables and models are required to obtain them. To make the available knowledge more user friendly, I have combined a number of state-of-the-art sources to create a 3-D (effective temperature, luminosity, and metallicity) grid of stellar models for which I provide calibrated SEDs and magnitudes as well as auxiliary variables such as mass and age. Furthermore, I have generated a grid of extinguished magnitudes using the recent Maíz Apellániz et al. (2012) extinction laws and incorporated them into the Bayesian code CHORIZOS (Maíz Apellániz 2004).

  6. 3-D Eutrophication Modeling for Lake Simcoe, Canada

    NASA Astrophysics Data System (ADS)

    Lu, Q.; Duckett, F.; Nairn, R.; Brunton, A.

    2006-12-01

    The Lake Simcoe Region Conservation Authority (LSRCA) and the Province of Ontario are undertaking a series of studies to facilitate management of the pressures of population growth in the Lake Simcoe watershed. With rapid population growth and urban development comes additional land clearing, storm water runoff and the discharge of treated sewage, all of which are sources of increased phosphorus loading to Lake Simcoe. Depressed oxygen levels were linked to phosphorous enrichment of the lake, with the resultant stimulation of algal growth in the sunlit upper waters of the lake, and its subsequent senescence and settling into the hypolimnion where bacterial decomposition consumes oxygen from the stratified waters. This poster describes a 3-D hydrodynamic, thermal and water quality model of Lake Simcoe developed using the Danish Hydraulics Institute (DHI) MIKE3 model. The hydrodynamic module includes wind-driven circulation, temperature variation, development of the thermocline and thermal stratification, and hydraulic forcing from inflowing tributaries. This is linked to the water quality module which simulates the eutrophication processes in the response of the lake to loadings of phosphorus, such as algal growth, the growth of aquatic plants and subsequent oxygen consumption. The model has been calibrated against Acoustic Doppler Current Profiler velocity data, plus measured temperature and water quality data at MOE stations in the lake and water intakes. The model is an important assessment tool for the management of the lake and its watersheds, allowing assessment of the impacts of the urban growth and land use change on the water quality in Lake Simcoe.

  7. 3-D GRACE gravity model for the 2011 Japan earthquake

    NASA Astrophysics Data System (ADS)

    Sastry, Rambhatla G.; Sonker, Mahendra K.

    2017-02-01

    The GRACE mission has contributed to the seismic characterization of major earthquakes in offshore regions of the world. Here, we isolate satellite gravity signal (μGal range) for the Japan Earthquake of 2011 using a difference method. Contrary to the existing gravity models, we propose a unit vertical pyramid based five-layer 3-D thrust fault model, which extends to the hypocenter and honors the ocean water layer and sea floor upheaval also. Our model partly uses existing seismological information (hypocenter depth of 32 km, rupture length of 300 km and vertical slip of 4 m), provides a snapshot of episodic subduction of the Pacific Plate below the Atlantic Plate and its gravity response closely matches the observed gravity (RMS error of 3.4012×10-13μGal), fully accounting for co-seismic mass redistribution including sea surface deformation. Our inferred rupture length, rupture velocity, average seismic moment magnitude and momentum, respectively, are 300 km, 4.49 km/s, 1.152×1021-1.8816×1021 N m and 2.319×106 GNs, which fairly agree with the literature. Further, our model inferred momentum at the sea floor corresponds to an area pulse that led to Tsunami generation.

  8. 3D numerical modeling of India-Asia-like collision

    NASA Astrophysics Data System (ADS)

    -Erika Püsök, Adina; Kaus, Boris; Popov, Anton

    2013-04-01

    above a strong mantle lithosphere - the jelly sandwich model (Burov and Watts, 2006). 3D models are thus needed to investigate these hypotheses. However, fully 3D models of the dynamics of continent collision zones have only been developed very recently, and presently most research groups have relied on certain explicit assumptions for their codes. Here, we employ the parallel 3D code LaMEM (Lithosphere and Mantle Evolution Model), with a finite difference staggered grid solver, which is capable of simulating lithospheric deformation while simultaneously taking mantle flow and a free surface into account. We here report on first lithospheric and upper-mantle scale simulations in which the Indian lithosphere is indented into Asia. Acknowledgements. Funding was provided by the European Research Council under the European Community's Seventh Framework Program (FP7/2007-2013) / ERC Grant agreement #258830. Numerical computations have been performed on JUQUEEN of the Jülich high-performance computing center. • Beaumont, C., Jamieson, R.A., Nguyen, M.H., Medvedev, S.E., 2004. Crustal channel flows: 1. Numerical models with applications to the tectonics of the Himalayan-Tibetan orogeny. J. Geophys. Res. 109, B06406. • Burov, E. & Watts, W.S., 2006. The long-term strength of continental lithosphere: "jelly sandwich" or "crème brûlée"?. GSA Today, 16, doi: 10.1130/1052-5173(2006)1016<1134:TLTSOC>1132.1130.CO;1132. • England P., Houseman, G., 1986. Finite strain calculations of continental deformation. 2. Comparison with the India-Asia collision zone. J. Geophys. Res.- Solid Earth and Planets 91 (B3), 3664-3676. • Jackson, J., 2002. Strength of the continental lithosphere: time to abandon the jelly sandwich?. GSA Today, September, 4-10. • Lechmann, S.M., May, D.A., Kaus, B.J.P., Schmalholz, S.M., 2011. Comparing thin-sheet models with 3D multilayer models for continental collision. Geophy. Int. J. doi: 10.1111/j.1365-246X.2011.05164.x • Royden, L.H., Burchfiel, B

  9. 3D Printing of Molecular Potential Energy Surface Models

    ERIC Educational Resources Information Center

    Lolur, Phalgun; Dawes, Richard

    2014-01-01

    Additive manufacturing, commonly known as 3D printing, is gaining popularity in a variety of applications and has recently become routinely available. Today, 3D printing services are not only found in engineering design labs and through online companies, but also in university libraries offering student access. In addition, affordable options for…

  10. 3D-Digital soil property mapping by geoadditive models

    NASA Astrophysics Data System (ADS)

    Papritz, Andreas

    2016-04-01

    In many digital soil mapping (DSM) applications, soil properties must be predicted not only for a single but for multiple soil depth intervals. In the GlobalSoilMap project, as an example, predictions are computed for the 0-5 cm, 5-15 cm, 15-30 cm, 30-60 cm, 60-100 cm, 100-200 cm depth intervals (Arrouays et al., 2014). Legacy soil data are often used for DSM. It is common for such datasets that soil properties were measured for soil horizons or for layers at varying soil depth and with non-constant thickness (support). This poses problems for DSM: One strategy is to harmonize the soil data to common depth prior to the analyses (e.g. Bishop et al., 1999) and conduct the statistical analyses for each depth interval independently. The disadvantage of this approach is that the predictions for different depths are computed independently from each other so that the predicted depth profiles may be unrealistic. Furthermore, the error induced by the harmonization to common depth is ignored in this approach (Orton et al. 2016). A better strategy is therefore to process all soil data jointly without prior harmonization by a 3D-analysis that takes soil depth and geographical position explicitly into account. Usually, the non-constant support of the data is then ignored, but Orton et al. (2016) presented recently a geostatistical approach that accounts for non-constant support of soil data and relies on restricted maximum likelihood estimation (REML) of a linear geostatistical model with a separable, heteroscedastic, zonal anisotropic auto-covariance function and area-to-point kriging (Kyriakidis, 2004.) Although this model is theoretically coherent and elegant, estimating its many parameters by REML and selecting covariates for the spatial mean function is a formidable task. A simpler approach might be to use geoadditive models (Kammann and Wand, 2003; Wand, 2003) for 3D-analyses of soil data. geoAM extend the scope of the linear model with spatially correlated errors to

  11. 3D Finite Difference Modelling of Basaltic Region

    NASA Astrophysics Data System (ADS)

    Engell-Sørensen, L.

    2003-04-01

    The main purpose of the work was to generate realistic data to be applied for testing of processing and migration tools for basaltic regions. The project is based on the three - dimensional finite difference code (FD), TIGER, made by Sintef. The FD code was optimized (parallelized) by the author, to run on parallel computers. The parallel code enables us to model large-scale realistic geological models and to apply traditional seismic and micro seismic sources. The parallel code uses multiple processors in order to manipulate subsets of large amounts of data simultaneously. The general anisotropic code uses 21 elastic coefficients. Eight independent coefficients are needed as input parameters for the general TI medium. In the FD code, the elastic wave field computation is implemented by a higher order FD solution to the elastic wave equation and the wave fields are computed on a staggered grid, shifted half a node in one or two directions. The geological model is a gridded basalt model, which covers from 24 km to 37 km of a real shot line in horizontal direction and from the water surface to the depth of 3.5 km. The 2frac {1}{2}D model has been constructed using the compound modeling software from Norsk Hydro. The vertical parameter distribution is obtained from observations in two wells. At The depth of between 1100 m to 1500 m, a basalt horizon covers the whole sub surface layers. We have shown that it is possible to simulate a line survey in realistic (3D) geological models in reasonable time by using high performance computers. The author would like to thank Norsk Hydro, Statoil, GEUS, and SINTEF for very helpful discussions and Parallab for being helpful with the new IBM, p690 Regatta system.

  12. Predicted 3D Model of the Rabies Virus Glycoprotein Trimer.

    PubMed

    Fernando, Bastida-González; Yersin, Celaya-Trejo; José, Correa-Basurto; Paola, Zárate-Segura

    2016-01-01

    The RABVG ectodomain is a homotrimer, and trimers are often called spikes. They are responsible for the attachment of the virus through the interaction with nicotinic acetylcholine receptors, neural cell adhesion molecule (NCAM), and the p75 neurotrophin receptor (p75NTR). This makes them relevant in viral pathogenesis. The antigenic structure differs significantly between the trimers and monomers. Surfaces rich in hydrophobic amino acids are important for trimer stabilization in which the C-terminal of the ectodomain plays an important role; to understand these interactions between the G proteins, a mechanistic study of their functions was performed with a molecular model of G protein in its trimeric form. This verified its 3D conformation. The molecular modeling of G protein was performed by a I-TASSER server and was evaluated via a Rachamandran plot and ERRAT program obtained 84.64% and 89.9% of the residues in the favorable regions and overall quality factor, respectively. The molecular dynamics simulations were carried out on RABVG trimer at 310 K. From these theoretical studies, we retrieved the RMSD values from Cα atoms to assess stability. Preliminary model of G protein of rabies virus stable at 12 ns with molecular dynamics was obtained.

  13. 3D finite element modeling of sliding wear

    NASA Astrophysics Data System (ADS)

    Buentello Hernandez, Rodolfo G.

    Wear is defined as "the removal of material volume through some mechanical process between two surfaces". There are many mechanical situations that can induce wear and each can involve many wear mechanisms. This research focuses on the mechanical wear due to dry sliding between two surfaces. Currently there is a need to identify and compare materials that would endure sliding wear under severe conditions such as high velocities. The high costs associated with the field experimentation of systems subject to high-speed sliding, has prevented the collection of the necessary data required to fully characterize this phenomena. Simulating wear through Finite Elements (FE) would enable its prediction under different scenarios and would reduce experimentation costs. In the aerospace, automotive and weapon industries such a model can aid in material selection, design and/or testing of systems subjected to wear in bearings, gears, brakes, gun barrels, slippers, locomotive wheels, or even rocket test tracks. The 3D wear model presented in this dissertation allows one to reasonably predict high-speed sliding mechanical wear between two materials. The model predictions are reasonable, when compared against those measured on a sled slipper traveling over the Holloman High Speed Tests Track. This slipper traveled a distance of 5,816 meters in 8.14 seconds and reached a maximum velocity of 1,530 m/s.

  14. Predicted 3D Model of the Rabies Virus Glycoprotein Trimer

    PubMed Central

    Fernando, Bastida-González; Yersin, Celaya-Trejo; José, Correa-Basurto; Paola, Zárate-Segura

    2016-01-01

    The RABVG ectodomain is a homotrimer, and trimers are often called spikes. They are responsible for the attachment of the virus through the interaction with nicotinic acetylcholine receptors, neural cell adhesion molecule (NCAM), and the p75 neurotrophin receptor (p75NTR). This makes them relevant in viral pathogenesis. The antigenic structure differs significantly between the trimers and monomers. Surfaces rich in hydrophobic amino acids are important for trimer stabilization in which the C-terminal of the ectodomain plays an important role; to understand these interactions between the G proteins, a mechanistic study of their functions was performed with a molecular model of G protein in its trimeric form. This verified its 3D conformation. The molecular modeling of G protein was performed by a I-TASSER server and was evaluated via a Rachamandran plot and ERRAT program obtained 84.64% and 89.9% of the residues in the favorable regions and overall quality factor, respectively. The molecular dynamics simulations were carried out on RABVG trimer at 310 K. From these theoretical studies, we retrieved the RMSD values from Cα atoms to assess stability. Preliminary model of G protein of rabies virus stable at 12 ns with molecular dynamics was obtained. PMID:27294109

  15. 3D modeling of patient-specific geometries of portal veins using MR images.

    PubMed

    Yang, Yan; George, Stephanie; Martin, Diego R; Tannenbaum, Allen R; Giddens, Don P

    2006-01-01

    In this note, we present an approach for developing patient-specific 3D models of portal veins to provide geometric boundary conditions for computational fluid dynamics (CFD) simulations of the blood flow inside portal veins. The study is based on MRI liver images of individual patients to which we apply image registration and segmentation techniques and inlet and outlet velocity profiles acquired using PC-MRI in the same imaging session. The portal vein and its connected veins are then extracted and visualized in 3D as surfaces. Image registration is performed to align shifted images between each breath-hold when the MRI images are acquired. The image segmentation method first labels each voxel in the 3D volume of interest by using a Bayesian probability approach, and then isolates the portal veins via active surfaces initialized inside the vessel. The method was tested with two healthy volunteers. In both cases, the main portal vein and its connected veins were successfully modeled and visualized.

  16. An in-depth spectroscopic examination of molecular bands from 3D hydrodynamical model atmospheres. II. Carbon-enhanced metal-poor 3D model atmospheres

    NASA Astrophysics Data System (ADS)

    Gallagher, A. J.; Caffau, E.; Bonifacio, P.; Ludwig, H.-G.; Steffen, M.; Homeier, D.; Plez, B.

    2017-02-01

    Context. Tighter constraints on metal-poor stars we observe are needed to better understand the chemical processes of the early Universe. Computing a stellar spectrum in 3D allows one to model complex stellar behaviours, which cannot be replicated in 1D. Aims: We examine the effect that the intrinsic CNO abundances have on a 3D model structure and the resulting 3D spectrum synthesis. Methods: Model atmospheres were computed in 3D for three distinct CNO chemical compositions using the CO5BOLD model atmosphere code, and their internal structures were examined. Synthetic spectra were computed from these models using Linfor3D and they were compared. New 3D abundance corrections for the G-band and a selection of UV OH lines were also computed. Results: The varying CNO abundances change the metal content of the 3D models. This had an effect on the model structure and the resulting synthesis. However, it was found that the C/O ratio had a larger effect than the overall metal content of a model. Conclusions: Our results suggest that varying the C/O ratio has a substantial impact on the internal structure of the 3D model, even in the hot turn-off star models explored here. This suggests that bespoke 3D models, for specific CNO abundances should be sought. Such effects are not seen in 1D at these temperature regimes.

  17. Kinetic modeling of 3D equilibria in a tokamak

    NASA Astrophysics Data System (ADS)

    Albert, C. G.; Heyn, M. F.; Kasilov, S. V.; Kernbichler, W.; Martitsch, A. F.; Runov, A. M.

    2016-11-01

    External resonant magnetic perturbations (RMPs) can modify the magnetic topology in a tokamak. In this case the magnetic field cannot generally be described by ideal MHD equilibrium equations in the vicinity of resonant magnetic surfaces where parallel and perpendicular relaxation timescales are comparable. Usually, resistive MHD models are used to describe these regions. In the present work, a kinetic model is used for this purpose. Within this model, plasma response, current and charge density are computed with help of a Monte Carlo method, where guiding center orbit equations are solved using a semianalytical geometrical integrator. Besides its higher efficiency in comparison to usual integrators this method is not sensitive to noise in field quantities. The computed charges and currents are used to calculate the electromagnetic field with help of a finite element solver. A preconditioned iterative scheme is applied to search for a self-consistent solution. The discussed method is aimed at the nonlinear kinetic description of RMPs in experiments on Edge Localized Mode (ELM) mitigation by external perturbation coil systems without simplification of the device geometry.

  18. A 3D model for rubber tyres contact, based on Kalker's methods through the STRIPES model

    NASA Astrophysics Data System (ADS)

    Chollet, Hugues

    2012-01-01

    A project on the pavement-rutting evolution under the effect of a tram on tyre, led the author to make a link between road and railway approaches to the problem of rolling contact. A simplified model is proposed with a fine description of the contact patch between a tyre and the road, and a more realistic pressure and shear stresses distribution than that available from basic models previously available. Experimental measurements are used to identify some characteristics of the force description, while the geometric shape of the tyre-road section are used, like in the traditional rail-wheel contact models, to build the 3D model. The last part validates a plausible contact pressure shape from self-aligning torque measurements and from Kalker's contact stresses gradient applied to the real tyre used in the project. The final result is a brush model extended from the wheel-rail STRIPES one, applicable to dynamics or contact studies of real tyres, with a physical coupling between longitudinal, lateral and spin effects, and a relatively fine description of the contact stresses along each strip of each tyre of the vehicle on an uneven road.

  19. Pros and Cons of ID vs. 3D Modeling

    NASA Technical Reports Server (NTRS)

    Klimchuk, James A.

    2012-01-01

    Advances in computing capability have led to tremendous improvements in 3D modeling. Entire active regions are being simulated in what might be described as a first principles way, in which plasma heating is treated self consistently rather than through the specification of heating functions. There are limitations to this approach, however, as actual heating mechanisms on the Sun involve spatial scales orders of magnitude smaller than what these simulations can resolve. Other simulations begin to resolve these scales, but they only treat a tiny volume and do not include the all important coupling with larger scales or with other parts of the atmosphere, and so cannot be readily compared with observations. Finally, ID hydrodynamic models capture the field-aligned evolution of the plasma extremely well and are ideally suited for data comparison, but they treat the heating in a totally ad hoc manner. All of these approaches have important contributions to make, but we must be aware of their limitations. I will highlight some of the strengths. and weaknesses of each.

  20. A 3D world model builder with a mobile robot

    SciTech Connect

    Zhang, Z.; Faugeras, O. )

    1992-08-01

    This article describes a system to incrementally build a world model with a mobile robot in an unknown environment. The model is, for the moment, segment based. A trinocular stereo system is used to build a local map about the environment. A global map is obtained by integrating a sequence of stereo frames taken when the robot navigates in the environment. The emphasis of this article is on the representation of the uncertainty of 3D segments from stereo and on the integration of segments from multiple views. The proposed representation is simple and very convenient to characterize the uncertainty of segment. A Kalman filter is used to merge matched line segments. An important characteristic of this integration strategy is that a segment observed by the stereo system corresponds only to one part of the segment in space, so the union of the different observations gives a better estimate on the segment in space. The authors have succeeded in integrating 35 stereo frames taken in their robot room.

  1. Modelling Polymer Deformation and Welding Behaviour during 3D Printing

    NASA Astrophysics Data System (ADS)

    McIlroy, Claire; Olmsted, Peter

    2016-11-01

    3D printing has the potential to transform manufacturing processes, yet improving the strength of printed parts, to equal that of traditionally-manufactured parts, remains an underlying issue. The most common method, fused deposition modelling, involves melting a thermoplastic, followed by layer-by-layer extrusion of the material to fabricate a three-dimensional object. The key to the ensuring strength at the weld between these layers is successful inter-diffusion. However, as the printed layer cools towards the glass transition temperature, the time available for diffusion is limited. In addition, the extrusion process significantly deforms the polymer micro-structure prior to welding and consequently affects how the polymers "re-entangle" across the weld. We have developed a simple model of the non-isothermal printing process to explore the effects that typical printing conditions and amorphous polymer rheology have on the ultimate weld structure. In particular, we incorporate both the stretch and orientation of the polymer using the Rolie-Poly constitutive equation to examine how the melt flows through the nozzle and is deposited onto the build plate. We then address how this deformation relaxes and contributes to the thickness and structure of the weld. National Institute for Standards and Technology (NIST) and Georgetown University.

  2. A novel mechanotactic 3D modeling of cell morphology

    NASA Astrophysics Data System (ADS)

    Jamaleddin Mousavi, Seyed; Hamdy Doweidar, Mohamed

    2014-08-01

    Cell morphology plays a critical role in many biological processes, such as cell migration, tissue development, wound healing and tumor growth. Recent investigations demonstrate that, among other stimuli, cells adapt their shapes according to their substrate stiffness. Until now, the development of this process has not been clear. Therefore, in this work, a new three-dimensional (3D) computational model for cell morphology has been developed. This model is based on a previous cell migration model presented by the same authors. The new model considers that during cell-substrate interaction, cell shape is governed by internal cell deformation, which leads to an accurate prediction of the cell shape according to the mechanical characteristic of its surrounding micro-environment. To study this phenomenon, the model has been applied to different numerical cases. The obtained results, which are qualitatively consistent with well-known related experimental works, indicate that cell morphology not only depends on substrate stiffness but also on the substrate boundary conditions. A cell located within an unconstrained soft substrate (several kPa) with uniform stiffness is unable to adhere to its substrate or to send out pseudopodia. When the substrate stiffness increases to tens of kPa (intermediate and rigid substrates), the cell can adequately adhere to its substrate. Subsequently, as the traction forces exerted by the cell increase, the cell elongates and its shape changes. Within very stiff (hard) substrates, the cell cannot penetrate into its substrate or send out pseudopodia. On the other hand, a cell is found to be more elongated within substrates with a constrained surface. However, this elongation decreases when the cell approaches it. It can be concluded that the higher the net traction force, the greater the cell elongation, the larger the cell membrane area, and the less random the cell alignment.

  3. Combining 3D printed forms with textile structures - mechanical and geometrical properties of multi-material systems

    NASA Astrophysics Data System (ADS)

    Sabantina, L.; Kinzel, F.; Ehrmann, A.; Finsterbusch, K.

    2015-07-01

    The 3D printing belongs to the rapidly emerging technologies which have the chance to revolutionize the way products are created. In the textile industry, several designers have already presented creations of shoes, dresses or other garments which could not be produced with common techniques. 3D printing, however, is still far away from being a usual process in textile and clothing production. The main challenge results from the insufficient mechanical properties, especially the low tensile strength, of pure 3D printed products, prohibiting them from replacing common technologies such as weaving or knitting. Thus, one way to the application of 3D printed forms in garments is combining them with textile fabrics, the latter ensuring the necessary tensile strength. This article reports about different approaches to combine 3D printed polymers with different textile materials and fabrics, showing chances and limits of this technique.

  4. Object-oriented urban 3D spatial data model organization method

    NASA Astrophysics Data System (ADS)

    Li, Jing-wen; Li, Wen-qing; Lv, Nan; Su, Tao

    2015-12-01

    This paper combined the 3d data model with object-oriented organization method, put forward the model of 3d data based on object-oriented method, implemented the city 3d model to quickly build logical semantic expression and model, solved the city 3d spatial information representation problem of the same location with multiple property and the same property with multiple locations, designed the space object structure of point, line, polygon, body for city of 3d spatial database, and provided a new thought and method for the city 3d GIS model and organization management.

  5. Lightning Modelling: From 3D to Circuit Approach

    NASA Astrophysics Data System (ADS)

    Moussa, H.; Abdi, M.; Issac, F.; Prost, D.

    2012-05-01

    The topic of this study is electromagnetic environment and electromagnetic interferences (EMI) effects, specifically the modelling of lightning indirect effects [1] on aircraft electrical systems present on deported and highly exposed equipments, such as nose landing gear (NLG) and nacelle, through a circuit approach. The main goal of the presented work, funded by a French national project: PREFACE, is to propose a simple equivalent electrical circuit to represent a geometrical structure, taking into account mutual, self inductances, and resistances, which play a fundamental role in the lightning current distribution. Then this model is intended to be coupled to a functional one, describing a power train chain composed of: a converter, a shielded power harness and a motor or a set of resistors used as a load for the converter. The novelty here, is to provide a pre-sizing qualitative approach allowing playing on integration in pre-design phases. This tool intends to offer a user-friendly way for replying rapidly to calls for tender, taking into account the lightning constraints. Two cases are analysed: first, a NLG that is composed of tubular pieces that can be easily approximated by equivalent cylindrical straight conductors. Therefore, passive R, L, M elements of the structure can be extracted through analytical engineer formulas such as those implemented in the partial element equivalent circuit (PEEC) [2] technique. Second, the same approach is intended to be applied on an electrical de-icing nacelle sub-system.

  6. 3D Loop Models and the CPn-1 Sigma Model

    NASA Astrophysics Data System (ADS)

    Nahum, Adam; Chalker, J. T.; Serna, P.; Ortuño, M.; Somoza, A. M.

    2011-09-01

    Many statistical mechanics problems can be framed in terms of random curves; we consider a class of three-dimensional loop models that are prototypes for such ensembles. The models show transitions between phases with infinite loops and short-loop phases. We map them to CPn-1 sigma models, where n is the loop fugacity. Using Monte Carlo simulations, we find continuous transitions for n=1, 2, 3, and first order transitions for n≥5. The results are relevant to line defects in random media, as well as to Anderson localization and (2+1)-dimensional quantum magnets.

  7. Using Geometry-Based Metrics as Part of Fitness-for-Purpose Evaluations of 3D City Models

    NASA Astrophysics Data System (ADS)

    Wong, K.; Ellul, C.

    2016-10-01

    Three-dimensional geospatial information is being increasingly used in a range of tasks beyond visualisation. 3D datasets, however, are often being produced without exact specifications and at mixed levels of geometric complexity. This leads to variations within the models' geometric and semantic complexity as well as the degree of deviation from the corresponding real world objects. Existing descriptors and measures of 3D data such as CityGML's level of detail are perhaps only partially sufficient in communicating data quality and fitness-for-purpose. This study investigates whether alternative, automated, geometry-based metrics describing the variation of complexity within 3D datasets could provide additional relevant information as part of a process of fitness-for-purpose evaluation. The metrics include: mean vertex/edge/face counts per building; vertex/face ratio; minimum 2D footprint area and; minimum feature length. Each metric was tested on six 3D city models from international locations. The results show that geometry-based metrics can provide additional information on 3D city models as part of fitness-for-purpose evaluations. The metrics, while they cannot be used in isolation, may provide a complement to enhance existing data descriptors if backed up with local knowledge, where possible.

  8. EM modeling for GPIR using 3D FDTD modeling codes

    SciTech Connect

    Nelson, S.D.

    1994-10-01

    An analysis of the one-, two-, and three-dimensional electrical characteristics of structural cement and concrete is presented. This work connects experimental efforts in characterizing cement and concrete in the frequency and time domains with the Finite Difference Time Domain (FDTD) modeling efforts of these substances. These efforts include Electromagnetic (EM) modeling of simple lossless homogeneous materials with aggregate and targets and the modeling dispersive and lossy materials with aggregate and complex target geometries for Ground Penetrating Imaging Radar (GPIR). Two- and three-dimensional FDTD codes (developed at LLNL) where used for the modeling efforts. Purpose of the experimental and modeling efforts is to gain knowledge about the electrical properties of concrete typically used in the construction industry for bridges and other load bearing structures. The goal is to optimize the performance of a high-sample-rate impulse radar and data acquisition system and to design an antenna system to match the characteristics of this material. Results show agreement to within 2 dB of the amplitudes of the experimental and modeled data while the frequency peaks correlate to within 10% the differences being due to the unknown exact nature of the aggregate placement.

  9. On 3-D inelastic analysis methods for hot section components. Volume 1: Special finite element models

    NASA Technical Reports Server (NTRS)

    Nakazawa, S.

    1987-01-01

    This Annual Status Report presents the results of work performed during the third year of the 3-D Inelastic Analysis Methods for Hot Section Components program (NASA Contract NAS3-23697). The objective of the program is to produce a series of new computer codes that permit more accurate and efficient three-dimensional analysis of selected hot section components, i.e., combustor liners, turbine blades, and turbine vanes. The computer codes embody a progression of mathematical models and are streamlined to take advantage of geometrical features, loading conditions, and forms of material response that distinguish each group of selected components. This report is presented in two volumes. Volume 1 describes effort performed under Task 4B, Special Finite Element Special Function Models, while Volume 2 concentrates on Task 4C, Advanced Special Functions Models.

  10. West Flank Coso, CA FORGE 3D temperature model

    SciTech Connect

    Doug Blankenship

    2016-03-01

    x,y,z data of the 3D temperature model for the West Flank Coso FORGE site. Model grid spacing is 250m. The temperature model for the Coso geothermal field used over 100 geothermal production sized wells and intermediate-depth temperature holes. At the near surface of this model, two boundary temperatures were assumed: (1) areas with surface manifestations, including fumaroles along the northeast striking normal faults and northwest striking dextral faults with the hydrothermal field, a temperature of ~104˚C was applied to datum at +1066 meters above sea level elevation, and (2) a near-surface temperature at about 10 meters depth, of 20˚C was applied below the diurnal and annual conductive temperature perturbations. These assumptions were based on heat flow studies conducted at the CVF and for the Mojave Desert. On the edges of the hydrothermal system, a 73˚C/km (4˚F/100’) temperature gradient contour was established using conductive gradient data from shallow and intermediate-depth temperature holes. This contour was continued to all elevation datums between the 20˚C surface and -1520 meters below mean sea level. Because the West Flank is outside of the geothermal field footprint, during Phase 1, the three wells inside the FORGE site were incorporated into the preexisting temperature model. To ensure a complete model was built based on all the available data sets, measured bottom-hole temperature gradients in certain wells were downward extrapolated to the next deepest elevation datum (or a maximum of about 25% of the well depth where conductive gradients are evident in the lower portions of the wells). After assuring that the margins of the geothermal field were going to be adequately modelled, the data was contoured using the Kriging method algorithm. Although the extrapolated temperatures and boundary conditions are not rigorous, the calculated temperatures are anticipated to be within ~6˚C (20˚F), or one contour interval, of the

  11. Prediction models from CAD models of 3D objects

    NASA Astrophysics Data System (ADS)

    Camps, Octavia I.

    1992-11-01

    In this paper we present a probabilistic prediction based approach for CAD-based object recognition. Given a CAD model of an object, the PREMIO system combines techniques of analytic graphics and physical models of lights and sensors to predict how features of the object will appear in images. In nearly 4,000 experiments on analytically-generated and real images, we show that in a semi-controlled environment, predicting the detectability of features of the image can successfully guide a search procedure to make informed choices of model and image features in its search for correspondences that can be used to hypothesize the pose of the object. Furthermore, we provide a rigorous experimental protocol that can be used to determine the optimal number of correspondences to seek so that the probability of failing to find a pose and of finding an inaccurate pose are minimized.

  12. 3D Simulation Modeling of the Tooth Wear Process.

    PubMed

    Dai, Ning; Hu, Jian; Liu, Hao

    2015-01-01

    Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation.

  13. 3D Simulation Modeling of the Tooth Wear Process

    PubMed Central

    Dai, Ning; Hu, Jian; Liu, Hao

    2015-01-01

    Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation. PMID:26241942

  14. Image-driven, model-based 3D abdominal motion estimation for MR-guided radiotherapy

    NASA Astrophysics Data System (ADS)

    Stemkens, Bjorn; Tijssen, Rob H. N.; de Senneville, Baudouin Denis; Lagendijk, Jan J. W.; van den Berg, Cornelis A. T.

    2016-07-01

    Respiratory motion introduces substantial uncertainties in abdominal radiotherapy for which traditionally large margins are used. The MR-Linac will open up the opportunity to acquire high resolution MR images just prior to radiation and during treatment. However, volumetric MRI time series are not able to characterize 3D tumor and organ-at-risk motion with sufficient temporal resolution. In this study we propose a method to estimate 3D deformation vector fields (DVFs) with high spatial and temporal resolution based on fast 2D imaging and a subject-specific motion model based on respiratory correlated MRI. In a pre-beam phase, a retrospectively sorted 4D-MRI is acquired, from which the motion is parameterized using a principal component analysis. This motion model is used in combination with fast 2D cine-MR images, which are acquired during radiation, to generate full field-of-view 3D DVFs with a temporal resolution of 476 ms. The geometrical accuracies of the input data (4D-MRI and 2D multi-slice acquisitions) and the fitting procedure were determined using an MR-compatible motion phantom and found to be 1.0-1.5 mm on average. The framework was tested on seven healthy volunteers for both the pancreas and the kidney. The calculated motion was independently validated using one of the 2D slices, with an average error of 1.45 mm. The calculated 3D DVFs can be used retrospectively for treatment simulations, plan evaluations, or to determine the accumulated dose for both the tumor and organs-at-risk on a subject-specific basis in MR-guided radiotherapy.

  15. Modeling 3-D Slope Stability of Coastal Bluffs Using 3-D Ground-Water Flow, Southwestern Seattle, Washington

    USGS Publications Warehouse

    Brien, Dianne L.; Reid, Mark E.

    2007-01-01

    Landslides are a common problem on coastal bluffs throughout the world. Along the coastal bluffs of the Puget Sound in Seattle, Washington, landslides range from small, shallow failures to large, deep-seated landslides. Landslides of all types can pose hazards to human lives and property, but deep-seated landslides are of significant concern because their large areal extent can cause extensive property damage. Although many geomorphic processes shape the coastal bluffs of Seattle, we focus on large (greater than 3,000 m3), deepseated, rotational landslides that occur on the steep bluffs along Puget Sound. Many of these larger failures occur in advance outwash deposits of the Vashon Drift (Qva); some failures extend into the underlying Lawton Clay Member of the Vashon Drift (Qvlc). The slope stability of coastal bluffs is controlled by the interplay of three-dimensional (3-D) variations in gravitational stress, strength, and pore-water pressure. We assess 3-D slope-stability using SCOOPS (Reid and others, 2000), a computer program that allows us to search a high-resolution digital-elevation model (DEM) to quantify the relative stability of all parts of the landscape by computing the stability and volume of thousands of potential spherical failures. SCOOPS incorporates topography, 3-D strength variations, and 3-D pore pressures. Initially, we use our 3-D analysis methods to examine the effects of topography and geology by using heterogeneous material properties, as defined by stratigraphy, without pore pressures. In this scenario, the least-stable areas are located on the steepest slopes, commonly in Qva or Qvlc. However, these locations do not agree well with observations of deep-seated landslides. Historically, both shallow colluvial landslides and deep-seated landslides have been observed near the contact between Qva and Qvlc, and commonly occur in Qva. The low hydraulic conductivity of Qvlc impedes ground-water flow, resulting in elevated pore pressures at the

  16. DC characterization and 3D modelling of a triangular, epoxy-impregnated high temperature superconducting coil

    NASA Astrophysics Data System (ADS)

    Hu, D.; Ainslie, M. D.; Rush, J. P.; Durrell, J. H.; Zou, J.; Raine, M. J.; Hampshire, D. P.

    2015-06-01

    The direct current (dc) characterization of high temperature superconducting (HTS) coils is important for applications, such as electric machines, superconducting magnetic energy storage and transformers. In this paper, the dc characterization of a triangular-shaped, epoxy-impregnated HTS coil wound with YBCO coated conductor intended for use in an axial-flux HTS motor is presented. Voltage was measured at several points along the coil to provide detailed information of its dc characteristics. The coil is modelled based on the H -formulation using a new three-dimensional (3D) technique that utilizes the real superconducting layer thickness, and this model allows simulation of the actual geometrical layout of the HTS coil structure. Detailed information on the critical current density’s dependence on the magnitude and orientation of the magnetic flux density, Jc(B,θ), determined from experimental measurement of a short sample of the coated conductor comprising the coil is included directly in the numerical model by a two-variable direct interpolation to avoid developing complicated equations for data fitting and greatly improve the computational speed. Issues related to meshing the finite elements of the real thickness 3D model are also discussed in detail. Based on a comparison of the measurement and simulation results, it is found that non-uniformity along the length exists in the coil, which implies imperfect superconducting properties in the coated conductor, and hence, coil. By evaluating the current-voltage (I-V) curves using the experimental data, and after taking into account a more practical n value and critical current for the non-uniform region, the modelling results show good agreement with the experimental results, validating this model as an appropriate tool to estimate the dc I-V relationship of a superconducting coil. This work provides a further step towards effective and efficient 3D modelling of superconducting devices for large

  17. Generation of Multi-Lod 3d City Models in Citygml with the Procedural Modelling Engine RANDOM3DCITY

    NASA Astrophysics Data System (ADS)

    Biljecki, F.; Ledoux, H.; Stoter, J.

    2016-09-01

    The production and dissemination of semantic 3D city models is rapidly increasing benefiting a growing number of use cases. However, their availability in multiple LODs and in the CityGML format is still problematic in practice. This hinders applications and experiments where multi-LOD datasets are required as input, for instance, to determine the performance of different LODs in a spatial analysis. An alternative approach to obtain 3D city models is to generate them with procedural modelling, which is - as we discuss in this paper - well suited as a method to source multi-LOD datasets useful for a number of applications. However, procedural modelling has not yet been employed for this purpose. Therefore, we have developed RANDOM3DCITY, an experimental procedural modelling engine for generating synthetic datasets of buildings and other urban features. The engine is designed to produce models in CityGML and does so in multiple LODs. Besides the generation of multiple geometric LODs, we implement the realisation of multiple levels of spatiosemantic coherence, geometric reference variants, and indoor representations. As a result of their permutations, each building can be generated in 392 different CityGML representations, an unprecedented number of modelling variants of the same feature. The datasets produced by RANDOM3DCITY are suited for several applications, as we show in this paper with documented uses. The developed engine is available under an open-source licence at Github at 3d/Random3Dcity"target="_blank">http://github.com/tudelft3d/Random3Dcity.

  18. High Rayleigh Number 3d Spherical Mantle Convection Models

    NASA Astrophysics Data System (ADS)

    Davies, J. H.

    2003-04-01

    The geochemical and geophysical evidence related to the mantle can potentially be reconciled by a hypothesis of whole mantle convection where the heterogeneity stems from the continuous recycling of oceanic crust, depleted lithospheric mantle and sediments. The mantle is expected to be well but not perfectly stirred, sampled differently in different tectonic settings, and with components having wide-ranging residence times. We might for example expect very long residence times for some buoyant or dense components that can reside in either the upper (lithosphere) or lower boundary (D''). We have started testing whether such a whole mantle convection hypothesis can satisfy wide ranging first order geophysical observations, such as plate velocities, stability of upwellings, geometry of downwellings, etc. The model parameters, including the mantle's viscosity structure, are guided by extensive earlier community work. We use TERRA to model compressible convection in a 3D spherical mantle shell with a depth dependent viscosity structure, where the lower mantle is 40 times more viscous than the upper mantle. A chondritic rate of internal heating of 6 x 10^-12 W/Kg was assumed, leading to Ra(H) = 3.4x10^8. A realistic depth dependent thermal expansivity and Murnaghan equation of state was assumed, with free slip b.c.. The evolution of the system was followed for 2 Billion years. The RMS surface velocity varied from around 4 - 7cm/yr, very similar to recent plate velocities. The structures in the lower mantle are relatively stable and larger length scale in comparison to the upper mantle features. The downwellings and upwellings are linear in planform but the upwellings are dominated by stronger upflow at the columns formed at their intersection. The upwelling features embedded in the lower mantle are very stable, and it is reasonable to expect (though yet to be demonstrated) that with temperature-dependent viscosity the upwellings will be dominated by the cylindrical

  19. Interpretation and mapping of geological features using mobile devices for 3D outcrop modelling

    NASA Astrophysics Data System (ADS)

    Buckley, Simon J.; Kehl, Christian; Mullins, James R.; Howell, John A.

    2016-04-01

    Advances in 3D digital geometric characterisation have resulted in widespread adoption in recent years, with photorealistic models utilised for interpretation, quantitative and qualitative analysis, as well as education, in an increasingly diverse range of geoscience applications. Topographic models created using lidar and photogrammetry, optionally combined with imagery from sensors such as hyperspectral and thermal cameras, are now becoming commonplace in geoscientific research. Mobile devices (tablets and smartphones) are maturing rapidly to become powerful field computers capable of displaying and interpreting 3D models directly in the field. With increasingly high-quality digital image capture, combined with on-board sensor pose estimation, mobile devices are, in addition, a source of primary data, which can be employed to enhance existing geological models. Adding supplementary image textures and 2D annotations to photorealistic models is therefore a desirable next step to complement conventional field geoscience. This contribution reports on research into field-based interpretation and conceptual sketching on images and photorealistic models on mobile devices, motivated by the desire to utilise digital outcrop models to generate high quality training images (TIs) for multipoint statistics (MPS) property modelling. Representative training images define sedimentological concepts and spatial relationships between elements in the system, which are subsequently modelled using artificial learning to populate geocellular models. Photorealistic outcrop models are underused sources of quantitative and qualitative information for generating TIs, explored further in this research by linking field and office workflows through the mobile device. Existing textured models are loaded to the mobile device, allowing rendering in a 3D environment. Because interpretation in 2D is more familiar and comfortable for users, the developed application allows new images to be captured

  20. Verification and Validation of the k-kL Turbulence Model in FUN3D and CFL3D Codes

    NASA Technical Reports Server (NTRS)

    Abdol-Hamid, Khaled S.; Carlson, Jan-Renee; Rumsey, Christopher L.

    2015-01-01

    The implementation of the k-kL turbulence model using multiple computational uid dy- namics (CFD) codes is reported herein. The k-kL model is a two-equation turbulence model based on Abdol-Hamid's closure and Menter's modi cation to Rotta's two-equation model. Rotta shows that a reliable transport equation can be formed from the turbulent length scale L, and the turbulent kinetic energy k. Rotta's equation is well suited for term-by-term mod- eling and displays useful features compared to other two-equation models. An important di erence is that this formulation leads to the inclusion of higher-order velocity derivatives in the source terms of the scale equations. This can enhance the ability of the Reynolds- averaged Navier-Stokes (RANS) solvers to simulate unsteady ows. The present report documents the formulation of the model as implemented in the CFD codes Fun3D and CFL3D. Methodology, veri cation and validation examples are shown. Attached and sepa- rated ow cases are documented and compared with experimental data. The results show generally very good comparisons with canonical and experimental data, as well as matching results code-to-code. The results from this formulation are similar or better than results using the SST turbulence model.

  1. Explicit 3D continuum fracture modeling with smooth particle hydrodynamics

    NASA Technical Reports Server (NTRS)

    Benz, W.; Asphaug, E.

    1993-01-01

    Impact phenomena shaped our solar system. As usual for most solar system processes, the scales are far different than we can address directly in the laboratory. Impact velocities are often much higher than we can achieve, sizes are often vastly larger, and most impacts take place in an environment where the only gravitational force is the mutual pull of the impactors. The Smooth Particle Hydrodynamics (SPH) technique has been applied in the past to the simulations of giant impacts. In these simulations, the colliding objects were so massive (at least a sizeable fraction of the Earth's mass) that material strength was negligible compared to gravity. This assumption can no longer be made when the bodies are much smaller. To this end, we have developed a 3D SPH code that includes a strength model to which we have added a von Mises yielding relation for stresses beyond the Hugoniot Elastic Limit. At the lower stresses associated with brittle failure, we use a rate-dependent strength based on the nucleation of incipient flaws whose number density is given by a Weibull distribution. Following Grady and Kipp and Melosh et al., we introduce a state variable D ('damage'), 0 less than D less than 1, which expresses the local reduction in strength due to crack growth under tensile loading. Unfortunately for the hydrodynamics, Grady and Kipp's model predicts which fragments are the most probable ones and not the ones that are really formed. This means, for example, that if a given laboratory experiment is modeled, the fragment distribution obtained from the Grady-Kipp theory would be equivalent to a ensemble average over many realizations of the experiment. On the other hand, the hydrodynamics itself is explicit and evolves not an ensemble average but very specific fragments. Hence, there is a clear incompatibility with the deterministic nature of the hydrodynamics equations and the statistical approach of the Grady-Kipp dynamical fracture model. We remedy these shortcomings

  2. Multi-sourced, 3D geometric characterization of volcanogenic karst features: Integrating lidar, sonar, and geophysical datasets (Invited)

    NASA Astrophysics Data System (ADS)

    Sharp, J. M.; Gary, M. O.; Reyes, R.; Halihan, T.; Fairfield, N.; Stone, W. C.

    2009-12-01

    Karstic aquifers can form very complex hydrogeological systems and 3-D mapping has been difficult, but Lidar, phased array sonar, and improved earth resistivity techniques show promise in this and in linking metadata to models. Zacatón, perhaps the Earth’s deepest cenote, has a sub-aquatic void space exceeding 7.5 x 106 cubic m3. It is the focus of this study which has created detailed 3D maps of the system. These maps include data from above and beneath the the water table and within the rock matrix to document the extent of the immense karst features and to interpret the geologic processes that formed them. Phase 1 used high resolution (20 mm) Lidar scanning of surficial features of four large cenotes. Scan locations, selected to achieve full feature coverage once registered, were established atop surface benchmarks with UTM coordinates established using GPS and Total Stations. The combined datasets form a geo-registered mesh of surface features down to water level in the cenotes. Phase 2 conducted subsurface imaging using Earth Resistivity Imaging (ERI) geophysics. ERI identified void spaces isolated from open flow conduits. A unique travertine morphology exists in which some cenotes are dry or contain shallow lakes with flat travertine floors; some water-filled cenotes have flat floors without the cone of collapse material; and some have collapse cones. We hypothesize that the floors may have large water-filled voids beneath them. Three separate flat travertine caps were imaged: 1) La Pilita, which is partially open, exposing cap structure over a deep water-filled shaft; 2) Poza Seca, which is dry and vegetated; and 3) Tule, which contains a shallow (<1 m) lake. A fourth line was run adjacent to cenote Verde. La Pilita ERI, verified by SCUBA, documented the existence of large water-filled void zones ERI at Poza Seca showed a thin cap overlying a conductive zone extending to at least 25 m depth beneath the cap with no lower boundary of this zone evident

  3. Historical Buildings Models and Their Handling via 3d Survey: from Points Clouds to User-Oriented Hbim

    NASA Astrophysics Data System (ADS)

    Chiabrando, F.; Sammartano, G.; Spanò, A.

    2016-06-01

    This paper retraces some research activities and application of 3D survey techniques and Building Information Modelling (BIM) in the environment of Cultural Heritage. It describes the diffusion of as-built BIM approach in the last years in Heritage Assets management, the so-called Built Heritage Information Modelling/Management (BHIMM or HBIM), that is nowadays an important and sustainable perspective in documentation and administration of historic buildings and structures. The work focuses the documentation derived from 3D survey techniques that can be understood like a significant and unavoidable knowledge base for the BIM conception and modelling, in the perspective of a coherent and complete management and valorisation of CH. It deepens potentialities, offered by 3D integrated survey techniques, to acquire productively and quite easilymany 3D information, not only geometrical but also radiometric attributes, helping the recognition, interpretation and characterization of state of conservation and degradation of architectural elements. From these data, they provide more and more high descriptive models corresponding to the geometrical complexity of buildings or aggregates in the well-known 5D (3D + time and cost dimensions). Points clouds derived from 3D survey acquisition (aerial and terrestrial photogrammetry, LiDAR and their integration) are reality-based models that can be use in a semi-automatic way to manage, interpret, and moderately simplify geometrical shapes of historical buildings that are examples, as is well known, of non-regular and complex geometry, instead of modern constructions with simple and regular ones. In the paper, some of these issues are addressed and analyzed through some experiences regarding the creation and the managing of HBIMprojects on historical heritage at different scales, using different platforms and various workflow. The paper focuses on LiDAR data handling with the aim to manage and extract geometrical information; on

  4. Numerical Results of 3-D Modeling of Moon Accumulation

    NASA Astrophysics Data System (ADS)

    Khachay, Yurie; Anfilogov, Vsevolod; Antipin, Alexandr

    2014-05-01

    For the last time for the model of the Moon usually had been used the model of mega impact in which the forming of the Earth and its sputnik had been the consequence of the Earth's collision with the body of Mercurial mass. But all dynamical models of the Earth's accumulation and the estimations after the Pb-Pb system, lead to the conclusion that the duration of the planet accumulation was about 1 milliard years. But isotopic results after the W-Hf system testify about a very early (5-10) million years, dividing of the geochemical reservoirs of the core and mantle. In [1,2] it is shown, that the account of energy dissipating by the decay of short living radioactive elements and first of all Al26,it is sufficient for heating even small bodies with dimensions about (50-100) km up to the iron melting temperature and can be realized a principal new differentiation mechanism. The inner parts of the melted preplanets can join and they are mainly of iron content, but the cold silicate fragments return to the supply zone and additionally change the content of Moon forming to silicates. Only after the increasing of the gravitational radius of the Earth, the growing area of the future Earth's core can save also the silicate envelope fragments [3]. For understanding the further system Earth-Moon evolution it is significant to trace the origin and evolution of heterogeneities, which occur on its accumulation stage.In that paper we are modeling the changing of temperature,pressure,velocity of matter flowing in a block of 3d spherical body with a growing radius. The boundary problem is solved by the finite-difference method for the system of equations, which include equations which describe the process of accumulation, the Safronov equation, the equation of impulse balance, equation Navier-Stocks, equation for above litho static pressure and heat conductivity in velocity-pressure variables using the Businesque approach.The numerical algorithm of the problem solution in velocity

  5. Induction Heating Process: 3D Modeling and Optimisation

    NASA Astrophysics Data System (ADS)

    Naar, R.; Bay, F.

    2011-05-01

    An increasing number of problems in mechanics and physics involves multiphysics coupled problems. Among these problems, we can often find electromagnetic coupled problems. Electromagnetic couplings may be involved through the use of direct or induced currents for thermal purposes—in order to generate heat inside a work piece in order to get either a prescribed temperature field or some given mechanical or metallurgical properties through an accurate control of temperature evolution with respect to time-, or for solid or fluid mechanics purposes—in order to create magnetic forces such as in fluid mechanics (electromagnetic stirring,…) or solid mechanics (magnetoforming,…). Induction heat treatment processes is therefore quite difficult to control; trying for instance to minimize distortions generated by such a process is not easy. In order to achieve these objectives, we have developed a computational tool which includes an optimsation stage. A 3D finite element modeling tool for local quenching after induction heating processes has already been developed in our laboratory. The modeling of such a multiphysics coupled process needs taking into account electromagnetic, thermal, mechanical and metallurgical phenomenon—as well as their mutual interactions during the whole process: heating and quenching. The model developed is based on Maxwell equations, heat transfer equation, mechanical equilibrium computations, Johnson-Mehl-Avrami and Koistinen-Marburger laws. All these equations and laws may be coupled but some coupling may be neglected. In our study, we will also focus on induction heating process aiming at optimising the Heat Affected Zone (HAZ). Thus problem is formalized as an optimization problem—minimizing a cost function which measures the difference between computed and optimal temperatures—along with some constraints on process parameters. The optimization algorithms may be of two kinds—either zero-order or first-order algorithms. First

  6. Dispelling dog dogma: an investigation of heterochrony in dogs using 3D geometric morphometric analysis of skull shape.

    PubMed

    Drake, Abby Grace

    2011-01-01

    Heterochrony is an evolutionary mechanism that generates diversity via perturbations of the rate or timing of development that requires very little genetic innovation. As such, heterochrony is thought to be a common evolutionary mechanism in the generation of diversity. Previous research has suggested that dogs evolved via heterochrony and are paedomorphic wolves. This study uses three-dimensional landmark-based coordinate data to investigate heterochronic patterns within the skull morphology of the domestic dog. A total of 677 adult dogs representing 106 different breeds were measured and compared with an ontogenetic series of 401 wolves. Geometric morphometric analysis reveals that the cranial shape of none of the modern breeds of dogs resembles the cranial shapes of adult or juvenile wolves. In addition, investigations of regional heterochrony in the face and neurocranium also reject the hypothesis of heterochrony. Throughout wolf cranial development the position of the face and the neurocranium remain in the same plane. Dogs, however, have a de novo cranial flexion in which the palate is tilted dorsally in brachycephalic and mesaticephalic breeds or tilted ventrally in dolichocephalic and down-face breeds. Dogs have evolved very rapidly into an incredibly morphologically diverse species with very little genetic variation. However, the genetic alterations to dog cranial development that have produced this vast range of phylogenetically novel skull shapes do not coincide with the expectations of the heterochronic model. Dogs are not paedomorphic wolves.

  7. Orbiter/External Tank Mate 3-D Solid Modeling

    NASA Technical Reports Server (NTRS)

    Godfrey, G. S.; Brandt, B.; Rorden, D.; Kapr, F.

    2004-01-01

    This research and development project presents an overview of the work completed while attending a summer 2004 American Society of Engineering Education/National Aeronautics and Space Administration (ASEE/NASA) Faculty Fellowship. This fellowship was completed at the Kennedy Space Center, Florida. The scope of the project was to complete parts, assemblies, and drawings that could be used by Ground Support Equipment (GSE) personnel to simulate situations and scenarios commonplace to the space shuttle Orbiter/External Tank (ET) Mate (50004). This mate takes place in the Vehicle Assembly Building (VAB). These simulations could then be used by NASA engineers as decision-making tools. During the summer of 2004, parts were created that defined the Orbiter/ET structural interfaces. Emphasis was placed upon assemblies that included the Orbiter/ET forward attachment (EO-1), aft left thrust strut (EO-2), aft right tripod support structure (EO-3), and crossbeam and aft feedline/umbilical supports. These assemblies are used to attach the Orbiter to the ET. The Orbiter/ET Mate assembly was then used to compare and analyze clearance distances using different Orbiter hang angles. It was found that a 30-minute arc angle change in Orbiter hang angle affected distance at the bipod strut to Orbiter yoke fitting 8.11 inches. A 3-D solid model library was established as a result of this project. This library contains parts, assemblies, and drawings translated into several formats. This library contains a collection of the following files: sti for sterolithography, stp for neutral file work, shrinkwrap for compression. tiff for photoshop work, jpeg for Internet use, and prt and asm for Pro/Engineer use. This library was made available to NASA engineers so that they could access its contents to make angle, load, and clearance analysis studies. These decision-making tools may be used by Pro/Engineer users and non-users.

  8. Automated robust generation of compact 3D statistical shape models

    NASA Astrophysics Data System (ADS)

    Vrtovec, Tomaz; Likar, Bostjan; Tomazevic, Dejan; Pernus, Franjo

    2004-05-01

    Ascertaining the detailed shape and spatial arrangement of anatomical structures is important not only within diagnostic settings but also in the areas of planning, simulation, intraoperative navigation, and tracking of pathology. Robust, accurate and efficient automated segmentation of anatomical structures is difficult because of their complexity and inter-patient variability. Furthermore, the position of the patient during image acquisition, the imaging device and protocol, image resolution, and other factors induce additional variations in shape and appearance. Statistical shape models (SSMs) have proven quite successful in capturing structural variability. A possible approach to obtain a 3D SSM is to extract reference voxels by precisely segmenting the structure in one, reference image. The corresponding voxels in other images are determined by registering the reference image to each other image. The SSM obtained in this way describes statistically plausible shape variations over the given population as well as variations due to imperfect registration. In this paper, we present a completely automated method that significantly reduces shape variations induced by imperfect registration, thus allowing a more accurate description of variations. At each iteration, the derived SSM is used for coarse registration, which is further improved by describing finer variations of the structure. The method was tested on 64 lumbar spinal column CT scans, from which 23, 38, 45, 46 and 42 volumes of interest containing vertebra L1, L2, L3, L4 and L5, respectively, were extracted. Separate SSMs were generated for each vertebra. The results show that the method is capable of reducing the variations induced by registration errors.

  9. 3D Geological Model of Nihe ore deposit Constrained by Gravity and Magnetic Modeling

    NASA Astrophysics Data System (ADS)

    Qi, Guang; Yan, Jiayong; Lv, Qingtan; Zhao, Jinhua

    2016-04-01

    We present a case study on using integrated geologic model in mineral exploration at depth. Nihe ore deposit in Anhui Province, is deep hidden ore deposit which was discovered in recent years, this finding is the major driving force of deep mineral exploration work in Luzong. Building 3D elaborate geological model has the important significance for prospecting to deep or surround in this area, and can help us better understand the metallogenic law and ore-controlling regularity. A 3D geological model, extending a depth from +200m to -1500m in Nihe ore deposit, has been compiled from surface geological map, cross-section, borehole logs and amounts of geological inference. And then the 3D geological models have been given physical property parameter for calculating the potential field. Modelling the potential response is proposed as means of evaluating the viability of the 3D geological models, and the evidence of making small changes to the uncertain parts of the original 3D geological models. It is expected that the final models not only reproduce supplied prior geological knowledge, but also explain the observed geophysical data. The workflow used to develop the 3D geologic model in this study includes the three major steps, as follows: (1) Determine the basic information of Model: Defining the 3D limits of the model area, the basic geological and structural unit, and the tectonic contact relations and the sedimentary sequences between these units. (2) 3D model construction: Firstly, a series of 2D geological cross sections over the model area are built by using all kinds of prior information, including surface geology, borehole data, seismic sections, and local geologists' knowledge and intuition. Lastly, we put these sections into a 3D environment according to their profile locations to build a 3D model by using geostatistics method. (3) 3D gravity and magnetic modeling: we calculate the potential field responses of the 3D model, and compare the predicted and

  10. Subjective surfaces: a geometric model for boundary completion

    SciTech Connect

    Sarti, Alessandro; Malladi, Ravi; Sethian, J.A.

    2000-06-01

    We present a geometric model and a computational method for segmentation of images with missing boundaries. In many situations, the human visual system fills in missing gaps in edges and boundaries, building and completing information that is not present. Boundary completion presents a considerable challenge in computer vision, since most algorithms attempt to exploit existing data. A large body of work concerns completion models, which postulate how to construct missing data; these models are often trained and specific to particular images. In this paper, we take the following, alternative perspective: we consider a reference point within an image as given, and then develop an algorithm which tries to build missing information on the basis of the given point of view and the available information as boundary data to the algorithm. Starting from this point of view, a surface is constructed. It is then evolved with the mean curvature flow in the metric induced by the image until a piecewise constant solution is reached. We test the computational model on modal completion, amodal completion, texture, photo and medical images. We extend the geometric model and the algorithm to 3D in order to extract shapes from low signal/noise ratio medical volumes. Results in 3D echocardiography and 3D fetal echography are presented.

  11. Modeling Computer Communication Networks in a Realistic 3D Environment

    DTIC Science & Technology

    2010-03-01

    visualization in OPNET . . . . . . . . . . . . 13 6. Sample NetViz visualization . . . . . . . . . . . . . . . . . . . 15 7. Realistic 3D terrains...scenario in OPNET . . . 19 10. OPNET 3DNV only displays connectivity . . . . . . . . . . . . 29 11. The digitally connected battlefield...confirmation tool 12 OPNET Optimized Network Evaluation Tool . . . . . . . . . . . . 13 NetViz Network Visualization

  12. 3D genome structure modeling by Lorentzian objective function.

    PubMed

    Trieu, Tuan; Cheng, Jianlin

    2016-11-29

    The 3D structure of the genome plays a vital role in biological processes such as gene interaction, gene regulation, DNA replication and genome methylation. Advanced chromosomal conformation capture techniques, such as Hi-C and tethered conformation capture, can generate chromosomal contact data that can be used to computationally reconstruct 3D structures of the genome. We developed a novel restraint-based method that is capable of reconstructing 3D genome structures utilizing both intra-and inter-chromosomal contact data. Our method was robust to noise and performed well in comparison with a panel of existing methods on a controlled simulated data set. On a real Hi-C data set of the human genome, our method produced chromosome and genome structures that are consistent with 3D FISH data and known knowledge about the human chromosome and genome, such as, chromosome territories and the cluster of small chromosomes in the nucleus center with the exception of the chromosome 18. The tool and experimental data are available at https://missouri.box.com/v/LorDG.

  13. Examination of 1D Solar Cell Model Limitations Using 3D SPICE Modeling: Preprint

    SciTech Connect

    McMahon, W. E.; Olson, J. M.; Geisz, J. F.; Friedman, D. J.

    2012-06-01

    To examine the limitations of one-dimensional (1D) solar cell modeling, 3D SPICE-based modeling is used to examine in detail the validity of the 1D assumptions as a function of sheet resistance for a model cell. The internal voltages and current densities produced by this modeling give additional insight into the differences between the 1D and 3D models.

  14. Quasi-Facial Communication for Online Learning Using 3D Modeling Techniques

    ERIC Educational Resources Information Center

    Wang, Yushun; Zhuang, Yueting

    2008-01-01

    Online interaction with 3D facial animation is an alternative way of face-to-face communication for distance education. 3D facial modeling is essential for virtual educational environments establishment. This article presents a novel 3D facial modeling solution that facilitates quasi-facial communication for online learning. Our algorithm builds…

  15. Numerical Results of Earth's Core Accumulation 3-D Modelling

    NASA Astrophysics Data System (ADS)

    Khachay, Yurie; Anfilogov, Vsevolod

    2013-04-01

    For a long time as a most convenient had been the model of mega impact in which the early forming of the Earth's core and mantle had been the consequence of formed protoplanet collision with the body of Mercurial mass. But all dynamical models of the Earth's accumulation and the estimations after the Pb-Pb system, lead to the conclusion that the duration of the planet accumulation was about 1 milliard years. But isotopic results after the W-Hf system testify about a very early (5-10) million years, dividing of the geochemical reservoirs of the core and mantle. In [1,3] it is shown, that the account of energy dissipating by the decay of short living radioactive elements and first of all Al,it is sufficient for heating even small bodies with dimensions about (50-100) km up to the iron melting temperature and can be realized a principal new differentiation mechanism. The inner parts of the melted preplanets can join and they are mainly of iron content, but the cold silicate fragments return to the supply zone. Only after the increasing of the gravitational radius, the growing area of the future core can save also the silicate envelope fragments. All existing dynamical accumulation models are constructed by using a spherical-symmetrical model. Hence for understanding the further planet evolution it is significant to trace the origin and evolution of heterogeneities, which occur on the planet accumulation stage. In that paper we are modeling distributions of temperature, pressure, velocity of matter flowing in a block of 3D- spherical body with a growing radius. The boundary problem is solved by the finite-difference method for the system of equations, which include equations which describe the process of accumulation, the Safronov equation, the equation of impulse balance, equation Navier-Stocks, equation for above litho static pressure and heat conductivity in velocity-pressure variables using the Businesque approach. The numerical algorithm of the problem solution in

  16. 3D Atmospheric Radiative Transfer for Cloud System-Resolving Models: Forward Modelling and Observations

    SciTech Connect

    Howard Barker; Jason Cole

    2012-05-17

    Utilization of cloud-resolving models and multi-dimensional radiative transfer models to investigate the importance of 3D radiation effects on the numerical simulation of cloud fields and their properties.

  17. Animation Strategies for Smooth Transformations Between Discrete Lods of 3d Building Models

    NASA Astrophysics Data System (ADS)

    Kada, Martin; Wichmann, Andreas; Filippovska, Yevgeniya; Hermes, Tobias

    2016-06-01

    The cartographic 3D visualization of urban areas has experienced tremendous progress over the last years. An increasing number of applications operate interactively in real-time and thus require advanced techniques to improve the quality and time response of dynamic scenes. The main focus of this article concentrates on the discussion of strategies for smooth transformation between two discrete levels of detail (LOD) of 3D building models that are represented as restricted triangle meshes. Because the operation order determines the geometrical and topological properties of the transformation process as well as its visual perception by a human viewer, three different strategies are proposed and subsequently analyzed. The simplest one orders transformation operations by the length of the edges to be collapsed, while the other two strategies introduce a general transformation direction in the form of a moving plane. This plane either pushes the nodes that need to be removed, e.g. during the transformation of a detailed LOD model to a coarser one, towards the main building body, or triggers the edge collapse operations used as transformation paths for the cartographic generalization.

  18. Fast, Automated, 3D Modeling of Building Interiors

    DTIC Science & Technology

    2012-10-30

    of thermographies with laser scanning point clouds [6]. Given the heterogeneous nature of the two modalities, we propose a feature-based approach...extract 2D lines from thermographies , and 3D lines are extracted through segmentation of the point cloud. Feature- matching and the relative pose between... thermographies and point cloud are obtained from an iterative procedure applied to detect and reject outliers; this includes rotation matrix and

  19. a Line-Based 3d Roof Model Reconstruction Algorithm: Tin-Merging and Reshaping (tmr)

    NASA Astrophysics Data System (ADS)

    Rau, J.-Y.

    2012-07-01

    Three-dimensional building model is one of the major components of a cyber-city and is vital for the realization of 3D GIS applications. In the last decade, the airborne laser scanning (ALS) data is widely used for 3D building model reconstruction and object extraction. Instead, based on 3D roof structural lines, this paper presents a novel algorithm for automatic roof models reconstruction. A line-based roof model reconstruction algorithm, called TIN-Merging and Reshaping (TMR), is proposed. The roof structural line, such as edges, eaves and ridges, can be measured manually from aerial stereo-pair, derived by feature line matching or inferred from ALS data. The originality of the TMR algorithm for 3D roof modelling is to perform geometric analysis and topology reconstruction among those unstructured lines and then reshapes the roof-type using elevation information from the 3D structural lines. For topology reconstruction, a line constrained Delaunay Triangulation algorithm is adopted where the input structural lines act as constraint and their vertex act as input points. Thus, the constructed TINs will not across the structural lines. Later at the stage of Merging, the shared edge between two TINs will be check if the original structural line exists. If not, those two TINs will be merged into a polygon. Iterative checking and merging of any two neighboured TINs/Polygons will result in roof polygons on the horizontal plane. Finally, at the Reshaping stage any two structural lines with fixed height will be used to adjust a planar function for the whole roof polygon. In case ALS data exist, the Reshaping stage can be simplified by adjusting the point cloud within the roof polygon. The proposed scheme reduces the complexity of 3D roof modelling and makes the modelling process easier. Five test datasets provided by ISPRS WG III/4 located at downtown Toronto, Canada and Vaihingen, Germany are used for experiment. The test sites cover high rise buildings and residential

  20. Model-based correction of velocity measurements in navigated 3-D ultrasound imaging during neurosurgical interventions.

    PubMed

    Iversen, Daniel Hoyer; Lindseth, Frank; Unsgaard, Geirmund; Torp, Hans; Lovstakken, Lasse

    2013-09-01

    In neurosurgery, information of blood flow is important to identify and avoid damage to important vessels. Three-dimensional intraoperative ultrasound color-Doppler imaging has proven useful in this respect. However, due to Doppler angle-dependencies and the complexity of the vascular architecture, clinical valuable 3-D information of flow direction and velocity is currently not available. In this work, we aim to correct for angle-dependencies in 3-D flow images based on a geometric model of the neurovascular tree generated on-the-fly from free-hand 2-D imaging and an accurate position sensor system. The 3-D vessel model acts as a priori information of vessel orientation used to angle-correct the Doppler measurements, as well as provide an estimate of the average flow direction. Based on the flow direction we were also able to do aliasing correction to approximately double the measurable velocity range. In vitro experiments revealed a high accuracy and robustness for estimating the mean direction of flow. Accurate angle-correction of axial velocities were possible given a sufficient beam-to-flow angle for at least parts of a vessel segment . In vitro experiments showed an absolute relative bias of 9.5% for a challenging low-flow scenario. The method also showed promising results in vivo, improving the depiction of flow in the distal branches of intracranial aneurysms and the feeding arteries of an arteriovenous malformation. Careful inspection by an experienced surgeon confirmed the correct flow direction for all in vivo examples.

  1. Numerical modelling of gravel unconstrained flow experiments with the DAN3D and RASH3D codes

    NASA Astrophysics Data System (ADS)

    Sauthier, Claire; Pirulli, Marina; Pisani, Gabriele; Scavia, Claudio; Labiouse, Vincent

    2015-12-01

    Landslide continuum dynamic models have improved considerably in the last years, but a consensus on the best method of calibrating the input resistance parameter values for predictive analyses has not yet emerged. In the present paper, numerical simulations of a series of laboratory experiments performed at the Laboratory for Rock Mechanics of the EPF Lausanne were undertaken with the RASH3D and DAN3D numerical codes. They aimed at analysing the possibility to use calibrated ranges of parameters (1) in a code different from that they were obtained from and (2) to simulate potential-events made of a material with the same characteristics as back-analysed past-events, but involving a different volume and propagation path. For this purpose, one of the four benchmark laboratory tests was used as past-event to calibrate the dynamic basal friction angle assuming a Coulomb-type behaviour of the sliding mass, and this back-analysed value was then used to simulate the three other experiments, assumed as potential-events. The computational findings show good correspondence with experimental results in terms of characteristics of the final deposits (i.e., runout, length and width). Furthermore, the obtained best fit values of the dynamic basal friction angle for the two codes turn out to be close to each other and within the range of values measured with pseudo-dynamic tilting tests.

  2. Virtual and Printed 3D Models for Teaching Crystal Symmetry and Point Groups

    ERIC Educational Resources Information Center

    Casas, Lluís; Estop, Euge`nia

    2015-01-01

    Both, virtual and printed 3D crystal models can help students and teachers deal with chemical education topics such as symmetry and point groups. In the present paper, two freely downloadable tools (interactive PDF files and a mobile app) are presented as examples of the application of 3D design to study point-symmetry. The use of 3D printing to…

  3. Analysis of 3D Modeling Software Usage Patterns for K-12 Students

    ERIC Educational Resources Information Center

    Wu, Yi-Chieh; Liao, Wen-Hung; Chi, Ming-Te; Li, Tsai-Yen

    2016-01-01

    In response to the recent trend in maker movement, teachers are learning 3D techniques actively and bringing 3D printing into the classroom to enhance variety and creativity in designing lectures. This study investigates the usage pattern of a 3D modeling software, Qmodel Creator, which is targeted at K-12 students. User logs containing…

  4. Geo-Referenced Dynamic Pushbroom Stereo Mosaics for 3D and Moving Target Extraction - A New Geometric Approach

    DTIC Science & Technology

    2009-12-01

    different real video sequences of large-scale 3D scenes to show the accuracy and effectiveness of the representation. Applications include airborne or ground...a moving platform, we will have to naturally and effectively handle obvious motion parallax and object occlusions in order to be able to detect...stereo mosaics of static scenes. These results are mainly presented in Sections 3 and 4. Second, an effective and efficient patch-based stereo

  5. ODTLES : a model for 3D turbulent flow based on one-dimensional turbulence modeling concepts.

    SciTech Connect

    McDermott, Randy; Kerstein, Alan R.; Schmidt, Rodney Cannon

    2005-01-01

    This report describes an approach for extending the one-dimensional turbulence (ODT) model of Kerstein [6] to treat turbulent flow in three-dimensional (3D) domains. This model, here called ODTLES, can also be viewed as a new LES model. In ODTLES, 3D aspects of the flow are captured by embedding three, mutually orthogonal, one-dimensional ODT domain arrays within a coarser 3D mesh. The ODTLES model is obtained by developing a consistent approach for dynamically coupling the different ODT line sets to each other and to the large scale processes that are resolved on the 3D mesh. The model is implemented computationally and its performance is tested and evaluated by performing simulations of decaying isotropic turbulence, a standard turbulent flow benchmarking problem.

  6. Robust automatic measurement of 3D scanned models for the human body fat estimation.

    PubMed

    Giachetti, Andrea; Lovato, Christian; Piscitelli, Francesco; Milanese, Chiara; Zancanaro, Carlo

    2015-03-01

    In this paper, we present an automatic tool for estimating geometrical parameters from 3-D human scans independent on pose and robustly against the topological noise. It is based on an automatic segmentation of body parts exploiting curve skeleton processing and ad hoc heuristics able to remove problems due to different acquisition poses and body types. The software is able to locate body trunk and limbs, detect their directions, and compute parameters like volumes, areas, girths, and lengths. Experimental results demonstrate that measurements provided by our system on 3-D body scans of normal and overweight subjects acquired in different poses are highly correlated with the body fat estimates obtained on the same subjects with dual-energy X-rays absorptiometry (DXA) scanning. In particular, maximal lengths and girths, not requiring precise localization of anatomical landmarks, demonstrate a good correlation (up to 96%) with the body fat and trunk fat. Regression models based on our automatic measurements can be used to predict body fat values reasonably well.

  7. Cloud-resolving component in the quasi-3D multi-scale modeling framework

    NASA Astrophysics Data System (ADS)

    Jung, Joon-Hee; Arakawa, Akio

    2010-05-01

    A quasi-3D multi-scale modeling framework (Q3D MMF), which combines a GCM with a Q3D CRM, is an attempt to include three dimensional cloud effects in a GCM without necessarily using a global cloud-resolving model. The horizontal domain of the Q3D CRM consists of two perpendicular sets of channels crossing at the center of a GCM grid box, each of which includes two grid-point arrays. Through coupling this structure with a GCM, the whole system of the Q3D MMF can converge to a fully 3D global CRM as the GCM's resolution is refined. Consequently, the horizontal resolution of the GCM can be freely chosen depending on the objective of application. However, due to the use of very narrow channels for the cloud-resolving component, its prediction algorithm must be specially designed. As a step in developing a Q3D MMF, we have first constructed a prediction algorithm for the Q3D CRM applying a 3D anelastic vector vorticity equation model to the Q3D network of grid points. Preliminary tests of the Q3D CRM have been performed for an idealized small domain. Comparing the results with those of the straightforward application of a 3D CRM, it is concluded that the Q3D CRM can reproduce most of the important statistics of the 3D solutions and the MMF based on the Q3D CRM will be a useful framework for climate modeling. This paper presents an outline of the Q3D algorithm and highlights of the results.

  8. Statistical Inverse Ray Tracing for Image-Based 3D Modeling.

    PubMed

    Liu, Shubao; Cooper, David B

    2014-10-01

    This paper proposes a new formulation and solution to image-based 3D modeling (aka "multi-view stereo") based on generative statistical modeling and inference. The proposed new approach, named statistical inverse ray tracing, models and estimates the occlusion relationship accurately through optimizing a physically sound image generation model based on volumetric ray tracing. Together with geometric priors, they are put together into a Bayesian formulation known as Markov random field (MRF) model. This MRF model is different from typical MRFs used in image analysis in the sense that the ray clique, which models the ray-tracing process, consists of thousands of random variables instead of two to dozens. To handle the computational challenges associated with large clique size, an algorithm with linear computational complexity is developed by exploiting, using dynamic programming, the recursive chain structure of the ray clique. We further demonstrate the benefit of exact modeling and accurate estimation of the occlusion relationship by evaluating the proposed algorithm on several challenging data sets.

  9. The MASH pipeline for protein function prediction and an algorithm for the geometric refinement of 3D motifs.

    PubMed

    Chen, Brian Y; Fofanov, Viacheslav Y; Bryant, Drew H; Dodson, Bradley D; Kristensen, David M; Lisewski, Andreas M; Kimmel, Marek; Lichtarge, Olivier; Kavraki, Lydia E

    2007-01-01

    The development of new and effective drugs is strongly affected by the need to identify drug targets and to reduce side effects. Resolving these issues depends partially on a thorough understanding of the biological function of proteins. Unfortunately, the experimental determination of protein function is expensive and time consuming. To support and accelerate the determination of protein functions, algorithms for function prediction are designed to gather evidence indicating functional similarity with well studied proteins. One such approach is the MASH pipeline, described in the first half of this paper. MASH identifies matches of geometric and chemical similarity between motifs, representing known functional sites, and substructures of functionally uncharacterized proteins (targets). Observations from several research groups concur that statistically significant matches can indicate functionally related active sites. One major subproblem is the design of effective motifs, which have many matches to functionally related targets (sensitive motifs), and few matches to functionally unrelated targets (specific motifs). Current techniques select and combine structural, physical, and evolutionary properties to generate motifs that mirror functional characteristics in active sites. This approach ignores incidental similarities that may occur with functionally unrelated proteins. To address this problem, we have developed Geometric Sieving (GS), a parallel distributed algorithm that efficiently refines motifs, designed by existing methods, into optimized motifs with maximal geometric and chemical dissimilarity from all known protein structures. In exhaustive comparison of all possible motifs based on the active sites of 10 well-studied proteins, we observed that optimized motifs were among the most sensitive and specific.

  10. TOPICAL REVIEW: Computational approaches to 3D modeling of RNA

    NASA Astrophysics Data System (ADS)

    Laing, Christian; Schlick, Tamar

    2010-07-01

    Many exciting discoveries have recently revealed the versatility of RNA and its importance in a variety of functions within the cell. Since the structural features of RNA are of major importance to their biological function, there is much interest in predicting RNA structure, either in free form or in interaction with various ligands, including proteins, metabolites and other molecules. In recent years, an increasing number of researchers have developed novel RNA algorithms for predicting RNA secondary and tertiary structures. In this review, we describe current experimental and computational advances and discuss recent ideas that are transforming the traditional view of RNA folding. To evaluate the performance of the most recent RNA 3D folding algorithms, we provide a comparative study in order to test the performance of available 3D structure prediction algorithms for an RNA data set of 43 structures of various lengths and motifs. We find that the algorithms vary widely in terms of prediction quality across different RNA lengths and topologies; most predictions have very large root mean square deviations from the experimental structure. We conclude by outlining some suggestions for future RNA folding research.

  11. Multiple representation approach to geometric model construction from range data

    NASA Astrophysics Data System (ADS)

    Koivunen, Visa; Vezien, Jean-Marc; Bajcsy, Ruzena

    1995-04-01

    A method is presented for constructing geometric design data from noisy 3-D sensor measurements of physical parts. In early processing phase, RLTS regression filters stemming from robust estimation theory are used for separating the desired part of the signal in contaminated sensor data from undesired part. Strategies for producing a complete 3-D data set from partial views are studied. Surface triangulation, NURBS, and superellipsoids are employed in model construction to be able to represent efficiently polygonal shapes, free form surfaces and standard primitive solids. Multiple representations are used because there is no single representation that would be most appropriate in all situations. The size of the required control point mesh for spline description is estimated using a surface characterization process. Surfaces of arbitrary topology are modeled using triangulation and trimmed NURBS. A user given tolerance value is driving refinement of the obtained surface model. The resulting model description is a procedural CAD model which can convey structural information in addition to low level geometric primitives. The model is translated to IGES standard product data exchange format to enable data sharing with other processes in concurrent engineering environment. Preliminary results on view registration and integration using simulated data are shown. Examples of model construction using both real and simulated data are also given.

  12. Scale Problems in Geometric-Kinematic Modelling of Geological Objects

    NASA Astrophysics Data System (ADS)

    Siehl, Agemar; Thomsen, Andreas

    To reveal, to render and to handle complex geological objects and their history of structural development, appropriate geometric models have to be designed. Geological maps, sections, sketches of strain and stress patterns are such well-known analogous two-dimensional models. Normally, the set of observations and measurements supporting them is small in relation to the complexity of the real objects they derive from. Therefore, modelling needs guidance by additional expert knowledge to bridge empty spaces which are not supported by data. Generating digital models of geological objects has some substantial advantages compared to conventional methods, especially if they are supported by an efficient database management system. Consistent 3D models of some complexity can be created, and experiments with time-dependent geological geometries may help to restore coherent sequences of paleogeological states. In order to cope with the problems arising from the combined usage of 3D-geometry models of different scale and resolution within an information system on subsurface geology, geometrical objects need to be annotated with information on the context, within which the geometry model has been established and within which it is valid, and methods supporting storage and retrieval as well as manipulation of geometry at different scales must also take into account and handle such context information to achieve meaningful results. An example is given of a detailed structural study of an open pit lignite mine in the Lower Rhine Basin.

  13. Validation of a numerical 3-D fluid-structure interaction model for a prosthetic valve based on experimental PIV measurements.

    PubMed

    Guivier-Curien, Carine; Deplano, Valérie; Bertrand, Eric

    2009-10-01

    A numerical 3-D fluid-structure interaction (FSI) model of a prosthetic aortic valve was developed, based on a commercial computational fluid dynamics (CFD) software program using an Arbitrary Eulerian Lagrangian (ALE) formulation. To make sure of the validity of this numerical model, an equivalent experimental model accounting for both the geometrical features and the hydrodynamic conditions was also developed. The leaflet and the flow behaviours around the bileaflet valve were investigated numerically and experimentally by performing particle image velocimetry (PIV) measurements. Through quantitative and qualitative comparisons, it was shown that the leaflet behaviour and the velocity fields were similar in both models. The present study allows the validation of a fully coupled 3-D FSI numerical model. The promising numerical tool could be therefore used to investigate clinical issues involving the aortic valve.

  14. A 3-D Geodynamic Model of Strain Partitioning in Southern California

    NASA Astrophysics Data System (ADS)

    Ye, J.; Liu, M.; Lin, F.

    2012-12-01

    In southern California, strain resulting from the relative motion between the Pacific and the North American plates is partitioned in a complex system of transcurrent, transcompressional, and transtensional faults. High-precision GPS measurements in this region have enabled kinematic modeling of the present-day strain partitioning between major faults in southern California. However, geodynamic models are needed to understand the cause of strain partitioning and to determine strain in regions where faults are blind or diffuse. We have developed a regional-scale geodynamic model of strain partitioning in southern California. This 3-D viscoelasto-plastic finite element model incorporates first-order fault geometry of the major active faults in the region. The model domain includes an elastoplastic upper crust on top of a viscoelastic lower lithospheric layer. Deformation is driven by the relative motion between the Pacific and the North American plates, imposed as a displacement boundary condition. Plastic deformation both within the fault zones and in the unfaulted surrounding crust is calculated. Our results show that the Big Bend of the San Andreas Fault, and other geometric complexity of faults in southern California, plays a major role in strain partitioning. The observed variations of strain portioning in southern California can be explained by the geometric configuration of fault systems relative to the relative plate motion, without appealing to basal traction of a flowing lower lithosphere. The model predicts concentrated plastic strain under the reverse fault systems in the Transverse Ranges and the young and diffuse faults in the Eastern California Shear Zone across the Mojave Desert, where a number damaging earthquakes occurred in the past decades.

  15. Procedural 3d Modelling for Traditional Settlements. The Case Study of Central Zagori

    NASA Astrophysics Data System (ADS)

    Kitsakis, D.; Tsiliakou, E.; Labropoulos, T.; Dimopoulou, E.

    2017-02-01

    Over the last decades 3D modelling has been a fast growing field in Geographic Information Science, extensively applied in various domains including reconstruction and visualization of cultural heritage, especially monuments and traditional settlements. Technological advances in computer graphics, allow for modelling of complex 3D objects achieving high precision and accuracy. Procedural modelling is an effective tool and a relatively novel method, based on algorithmic modelling concept. It is utilized for the generation of accurate 3D models and composite facade textures from sets of rules which are called Computer Generated Architecture grammars (CGA grammars), defining the objects' detailed geometry, rather than altering or editing the model manually. In this paper, procedural modelling tools have been exploited to generate the 3D model of a traditional settlement in the region of Central Zagori in Greece. The detailed geometries of 3D models derived from the application of shape grammars on selected footprints, and the process resulted in a final 3D model, optimally describing the built environment of Central Zagori, in three levels of Detail (LoD). The final 3D scene was exported and published as 3D web-scene which can be viewed with 3D CityEngine viewer, giving a walkthrough the whole model, same as in virtual reality or game environments. This research work addresses issues regarding textures' precision, LoD for 3D objects and interactive visualization within one 3D scene, as well as the effectiveness of large scale modelling, along with the benefits and drawbacks that derive from procedural modelling techniques in the field of cultural heritage and more specifically on 3D modelling of traditional settlements.

  16. Construction of a 3D model of cytochrome P450 2B4.

    PubMed

    Chang, Y T; Stiffelman, O B; Vakser, I A; Loew, G H; Bridges, A; Waskell, L

    1997-02-01

    A three-dimensional structural model of rabbit phenobarbital-inducible cytochrome P450 2B4 (LM2) was constructed by homology modeling techniques previously developed for building and evaluating a 3D model of the cytochrome P450choP isozyme. Four templates with known crystal structures including cytochrome P450cam, terp, BM-3 and eryF were used in multiple sequence alignments and construction of the cytochrome P450 2B4 coordinates. The model was evaluated for its overall quality using available protein analysis programs and found to be satisfactory. The model structure was stable at room temperature during a 140 ps unconstrained full protein molecular dynamics simulation. A putative substrate access channel and binding site were identified. Two different substrates, benzphetamine and androstenedione, that are metabolized by cytochrome P450 2B4 with pronounced product specificity were docked into the putative binding site. Two orientations were found for each substrate that could lead to the observed preferred products. Using a geometric fit method three regions on the surface of the model cytochrome P450 structure were identified as possible sites for interaction with cytochrome b5, a redox partner of P450 2B4. Residues that may interact with the substrates and with cytochrome b5 have been identified and mutagenesis studies are currently in progress.

  17. Development of 3D electromagnetic modeling tools for airborne vehicles

    NASA Technical Reports Server (NTRS)

    Volakis, John L.

    1992-01-01

    The main goal of this report is to advance the development of methodologies for scattering by airborne composite vehicles. Although the primary focus continues to be the development of a general purpose computer code for analyzing the entire structure as a single unit, a number of other tasks are also being pursued in parallel with this effort. One of these tasks discussed within is on new finite element formulations and mesh termination schemes. The goal here is to decrease computation time while retaining accuracy and geometric adaptability.The second task focuses on the application of wavelets to electromagnetics. Wavelet transformations are shown to be able to reduce a full matrix to a band matrix, thereby reducing the solutions memory requirements. Included within this document are two separate papers on finite element formulations and wavelets.

  18. A Deformable Generic 3D Model of Haptoral Anchor of Monogenean

    PubMed Central

    Teo, Bee Guan; Dhillon, Sarinder Kaur; Lim, Lee Hong Susan

    2013-01-01

    In this paper, a digital 3D model which allows for visualisation in three dimensions and interactive manipulation is explored as a tool to help us understand the structural morphology and elucidate the functions of morphological structures of fragile microorganisms which defy live studies. We developed a deformable generic 3D model of haptoral anchor of dactylogyridean monogeneans that can subsequently be deformed into different desired anchor shapes by using direct manipulation deformation technique. We used point primitives to construct the rectangular building blocks to develop our deformable 3D model. Point primitives are manually marked on a 2D illustration of an anchor on a Cartesian graph paper and a set of Cartesian coordinates for each point primitive is manually extracted from the graph paper. A Python script is then written in Blender to construct 3D rectangular building blocks based on the Cartesian coordinates. The rectangular building blocks are stacked on top or by the side of each other following their respective Cartesian coordinates of point primitive. More point primitives are added at the sites in the 3D model where more structural variations are likely to occur, in order to generate complex anchor structures. We used Catmull-Clark subdivision surface modifier to smoothen the surface and edge of the generic 3D model to obtain a smoother and more natural 3D shape and antialiasing option to reduce the jagged edges of the 3D model. This deformable generic 3D model can be deformed into different desired 3D anchor shapes through direct manipulation deformation technique by aligning the vertices (pilot points) of the newly developed deformable generic 3D model onto the 2D illustrations of the desired shapes and moving the vertices until the desire 3D shapes are formed. In this generic 3D model all the vertices present are deployed for displacement during deformation. PMID:24204903

  19. A deformable generic 3D model of haptoral anchor of Monogenean.

    PubMed

    Teo, Bee Guan; Dhillon, Sarinder Kaur; Lim, Lee Hong Susan

    2013-01-01

    In this paper, a digital 3D model which allows for visualisation in three dimensions and interactive manipulation is explored as a tool to help us understand the structural morphology and elucidate the functions of morphological structures of fragile microorganisms which defy live studies. We developed a deformable generic 3D model of haptoral anchor of dactylogyridean monogeneans that can subsequently be deformed into different desired anchor shapes by using direct manipulation deformation technique. We used point primitives to construct the rectangular building blocks to develop our deformable 3D model. Point primitives are manually marked on a 2D illustration of an anchor on a Cartesian graph paper and a set of Cartesian coordinates for each point primitive is manually extracted from the graph paper. A Python script is then written in Blender to construct 3D rectangular building blocks based on the Cartesian coordinates. The rectangular building blocks are stacked on top or by the side of each other following their respective Cartesian coordinates of point primitive. More point primitives are added at the sites in the 3D model where more structural variations are likely to occur, in order to generate complex anchor structures. We used Catmull-Clark subdivision surface modifier to smoothen the surface and edge of the generic 3D model to obtain a smoother and more natural 3D shape and antialiasing option to reduce the jagged edges of the 3D model. This deformable generic 3D model can be deformed into different desired 3D anchor shapes through direct manipulation deformation technique by aligning the vertices (pilot points) of the newly developed deformable generic 3D model onto the 2D illustrations of the desired shapes and moving the vertices until the desire 3D shapes are formed. In this generic 3D model all the vertices present are deployed for displacement during deformation.

  20. Establishing a National 3d Geo-Data Model for Building Data Compliant to Citygml: Case of Turkey

    NASA Astrophysics Data System (ADS)

    Ates Aydar, S.; Stoter, J.; Ledoux, H.; Demir Ozbek, E.; Yomralioglu, T.

    2016-06-01

    This paper presents the generation of the 3D national building geo-data model of Turkey, which is compatible with the international OGC CityGML Encoding Standard. We prepare an ADE named CityGML-TRKBIS.BI that is produced by extending existing thematic modules of CityGML according to TRKBIS needs. All thematic data groups in TRKBIS geo-data model have been remodelled in order to generate the national large scale 3D geo-data model for Turkey. Specific attention has been paid to data groups that have different class structure according to related CityGML data themes such as building data model. Current 2D geo-information model for building data theme of Turkey (TRKBIS.BI) was established based on INSPIRE specifications for building (Core 2D and Extended 2D profiles), ISO/TC 211 standards and OGC web services. New version of TRKBIS.BI which is established according to semantic and geometric rules of CityGML will represent 2D-2.5D and 3D objects. After a short overview on generic approach, this paper describes extending CityGML building data theme according to TRKBIS.BI through several steps. First, building models of both standards were compared according to their data structure, classes and attributes. Second, CityGML building model was extended with respect to TRKBIS needs and CityGML-TRKBIS Building ADE was established in UML. This study provides new insights into 3D applications in Turkey. The generated 3D geo-data model for building thematic class will be used as a common exchange format that meets 2D, 2.5D and 3D implementation needs at national level.

  1. Large scale 3-D modeling by integration of resistivity models and borehole data through inversion

    NASA Astrophysics Data System (ADS)

    Foged, N.; Marker, P. A.; Christansen, A. V.; Bauer-Gottwein, P.; Jørgensen, F.; Høyer, A.-S.; Auken, E.

    2014-02-01

    We present an automatic method for parameterization of a 3-D model of the subsurface, integrating lithological information from boreholes with resistivity models through an inverse optimization, with the objective of further detailing for geological models or as direct input to groundwater models. The parameter of interest is the clay fraction, expressed as the relative length of clay-units in a depth interval. The clay fraction is obtained from lithological logs and the clay fraction from the resistivity is obtained by establishing a simple petrophysical relationship, a translator function, between resistivity and the clay fraction. Through inversion we use the lithological data and the resistivity data to determine the optimum spatially distributed translator function. Applying the translator function we get a 3-D clay fraction model, which holds information from the resistivity dataset and the borehole dataset in one variable. Finally, we use k means clustering to generate a 3-D model of the subsurface structures. We apply the concept to the Norsminde survey in Denmark integrating approximately 700 boreholes and more than 100 000 resistivity models from an airborne survey in the parameterization of the 3-D model covering 156 km2. The final five-cluster 3-D model differentiates between clay materials and different high resistive materials from information held in resistivity model and borehole observations respectively.

  2. Large-scale 3-D modeling by integration of resistivity models and borehole data through inversion

    NASA Astrophysics Data System (ADS)

    Foged, N.; Marker, P. A.; Christansen, A. V.; Bauer-Gottwein, P.; Jørgensen, F.; Høyer, A.-S.; Auken, E.

    2014-11-01

    We present an automatic method for parameterization of a 3-D model of the subsurface, integrating lithological information from boreholes with resistivity models through an inverse optimization, with the objective of further detailing of geological models, or as direct input into groundwater models. The parameter of interest is the clay fraction, expressed as the relative length of clay units in a depth interval. The clay fraction is obtained from lithological logs and the clay fraction from the resistivity is obtained by establishing a simple petrophysical relationship, a translator function, between resistivity and the clay fraction. Through inversion we use the lithological data and the resistivity data to determine the optimum spatially distributed translator function. Applying the translator function we get a 3-D clay fraction model, which holds information from the resistivity data set and the borehole data set in one variable. Finally, we use k-means clustering to generate a 3-D model of the subsurface structures. We apply the procedure to the Norsminde survey in Denmark, integrating approximately 700 boreholes and more than 100 000 resistivity models from an airborne survey in the parameterization of the 3-D model covering 156 km2. The final five-cluster 3-D model differentiates between clay materials and different high-resistivity materials from information held in the resistivity model and borehole observations, respectively.

  3. A Quantification of the 3D Modeling Capabilities of the Kinectfusion Algorithm

    DTIC Science & Technology

    2014-03-27

    A QUANTIFICATION OF THE 3D MODELING CAPABILITIES OF THE KINECTFUSTION ALGORITHM THESIS Jeremy M. Higbee, Captain, USAF AFIT-ENG-14-M-40 DEPARTMENT OF...subject to copyright protection in the United States. AFIT-ENG-14-M-40 A QUANTIFICATION OF THE 3D MODELING CAPABILITIES OF THE KINECTFUSTION ALGORITHM...M-40 A QUANTIFICATION OF THE 3D MODELING CAPABILITIES OF THE KINECTFUSTION ALGORITHM Jeremy M. Higbee, BS Captain, USAF Approved: /signed/ Maj Brian

  4. Geometric Modeling Application Interface Program

    DTIC Science & Technology

    1990-11-01

    Manual IDEF-Extended ( IDEFIX ) Integrated Information Support System (IISS), ICAM Project 6201, Contract F33615-80-C-5155, December 1985. Interim...Differential Geometry of Curves and Surfaces, M. P. de Carmo, Prentice-Hall, Inc., 1976. IDEFIX Readers Reference, D. Appleton Company, December 1985...Modeling. IDEFI -- IDEF Information Modeling. IDEFIX -- IDEF Extended Information Modeling. IDEF2 -- IDEF Dynamics Modeling. IDSS -- Integrated Decision

  5. Implementation of algebraic stress models in a general 3-D Navier-Stokes method (PAB3D)

    NASA Technical Reports Server (NTRS)

    Abdol-Hamid, Khaled S.

    1995-01-01

    A three-dimensional multiblock Navier-Stokes code, PAB3D, which was developed for propulsion integration and general aerodynamic analysis, has been used extensively by NASA Langley and other organizations to perform both internal (exhaust) and external flow analysis of complex aircraft configurations. This code was designed to solve the simplified Reynolds Averaged Navier-Stokes equations. A two-equation k-epsilon turbulence model has been used with considerable success, especially for attached flows. Accurate predicting of transonic shock wave location and pressure recovery in separated flow regions has been more difficult. Two algebraic Reynolds stress models (ASM) have been recently implemented in the code that greatly improved the code's ability to predict these difficult flow conditions. Good agreement with Direct Numerical Simulation (DNS) for a subsonic flat plate was achieved with ASM's developed by Shih, Zhu, and Lumley and Gatski and Speziale. Good predictions were also achieved at subsonic and transonic Mach numbers for shock location and trailing edge boattail pressure recovery on a single-engine afterbody/nozzle model.

  6. Developing and Testing a 3d Cadastral Data Model a Case Study in Australia

    NASA Astrophysics Data System (ADS)

    Aien, A.; Kalantari, M.; Rajabifard, A.; Williamson, I. P.; Shojaei, D.

    2012-07-01

    Population growth, urbanization and industrialization place more pressure on land use with the need for increased space. To extend the use and functionality of the land, complex infrastructures are being built, both vertically and horizontally, layered and stacked. These three-dimensional (3D) developments affect the interests (Rights, Restrictions, and Responsibilities (RRRs)) attached to the underlying land. A 3D cadastre will assist in managing the effects of 3D development on a particular extent of land. There are many elements that contribute to developing a 3D cadastre, such as existing of 3D property legislations, 3D DBMS, 3D visualization. However, data modelling is one of the most important elements of a successful 3D cadastre. As architectural models of houses and high rise buildings help their users visualize the final product, 3D cadastre data model supports 3D cadastre users to understand the structure or behavior of the system and has a template that guides them to construct and implement the 3D cadastre. Many jurisdictions, organizations and software developers have built their own cadastral data model. Land Administration Domain Model (DIS-ISO 19152, The Netherlands) and ePlan (Intergovernmental Committee on Surveying and Mapping, Australia) are examples of existing data models. The variation between these data models is the result of different attitudes towards cadastres. However, there is a basic common thread among them all. Current cadastral data models use a 2D land-parcel concept and extend it to support 3D requirements. These data models cannot adequately manage and represent the spatial extent of 3D RRRs. Most of the current cadastral data models have been influenced by a very broad understanding of 3D cadastral concepts because better clarity in what needs to be represented and analysed in the cadastre needs to be established. This paper presents the first version of a 3D Cadastral Data Model (3DCDM_Version 1.0). 3DCDM models both the legal

  7. Detection of Disease Symptoms on Hyperspectral 3d Plant Models

    NASA Astrophysics Data System (ADS)

    Roscher, Ribana; Behmann, Jan; Mahlein, Anne-Katrin; Dupuis, Jan; Kuhlmann, Heiner; Plümer, Lutz

    2016-06-01

    We analyze the benefit of combining hyperspectral images information with 3D geometry information for the detection of Cercospora leaf spot disease symptoms on sugar beet plants. Besides commonly used one-class Support Vector Machines, we utilize an unsupervised sparse representation-based approach with group sparsity prior. Geometry information is incorporated by representing each sample of interest with an inclination-sorted dictionary, which can be seen as an 1D topographic dictionary. We compare this approach with a sparse representation based approach without geometry information and One-Class Support Vector Machines. One-Class Support Vector Machines are applied to hyperspectral data without geometry information as well as to hyperspectral images with additional pixelwise inclination information. Our results show a gain in accuracy when using geometry information beside spectral information regardless of the used approach. However, both methods have different demands on the data when applied to new test data sets. One-Class Support Vector Machines require full inclination information on test and training data whereas the topographic dictionary approach only need spectral information for reconstruction of test data once the dictionary is build by spectra with inclination.

  8. The Influence of Selected Parameters on Evaluation of the Geometrical Shape Deviation - Cylindricity in 3D Measuring Machine Workspace

    NASA Astrophysics Data System (ADS)

    Drbúl, Mário; Šajgalík, Michal; Litvaj, lvan; Babík, Ondrej

    2016-12-01

    Each part as a final product and its surface is composed of various geometric elements, although at first glance seem as smooth and shiny. During the manufacturing process, there is a number of influences (e.g. selected manufacturing technology, production process, human factors, the strategy of measurement, scanning speed, shape of the measurement contact tip, temperature, or the surface tension and the like), which hinder the production of component with ideally shaped elements. From the economic and design point of view (in accordance with determined GPS standards), there is necessary fast and accurate analyze and evaluate these elements. Presented article deals with the influence of scanning speed and measuring strategy for assessment of shape deviations.

  9. A new approach towards image based virtual 3D city modeling by using close range photogrammetry

    NASA Astrophysics Data System (ADS)

    Singh, S. P.; Jain, K.; Mandla, V. R.

    2014-05-01

    3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing day to day for various engineering and non-engineering applications. Generally three main image based approaches are using for virtual 3D city models generation. In first approach, researchers used Sketch based modeling, second method is Procedural grammar based modeling and third approach is Close range photogrammetry based modeling. Literature study shows that till date, there is no complete solution available to create complete 3D city model by using images. These image based methods also have limitations This paper gives a new approach towards image based virtual 3D city modeling by using close range photogrammetry. This approach is divided into three sections. First, data acquisition process, second is 3D data processing, and third is data combination process. In data acquisition process, a multi-camera setup developed and used for video recording of an area. Image frames created from video data. Minimum required and suitable video image frame selected for 3D processing. In second section, based on close range photogrammetric principles and computer vision techniques, 3D model of area created. In third section, this 3D model exported to adding and merging of other pieces of large area. Scaling and alignment of 3D model was done. After applying the texturing and rendering on this model, a final photo-realistic textured 3D model created. This 3D model transferred into walk-through model or in movie form. Most of the processing steps are automatic. So this method is cost effective and less laborious. Accuracy of this model is good. For this research work, study area is the campus of department of civil engineering, Indian Institute of Technology, Roorkee. This campus acts as a prototype for city. Aerial photography is restricted in many country

  10. Model-based measurement of food portion size for image-based dietary assessment using 3D/2D registration

    NASA Astrophysics Data System (ADS)

    Chen, Hsin-Chen; Jia, Wenyan; Yue, Yaofeng; Li, Zhaoxin; Sun, Yung-Nien; Fernstrom, John D.; Sun, Mingui

    2013-10-01

    Dietary assessment is important in health maintenance and intervention in many chronic conditions, such as obesity, diabetes and cardiovascular disease. However, there is currently a lack of convenient methods for measuring the volume of food (portion size) in real-life settings. We present a computational method to estimate food volume from a single photographic image of food contained on a typical dining plate. First, we calculate the food location with respect to a 3D camera coordinate system using the plate as a scale reference. Then, the food is segmented automatically from the background in the image. Adaptive thresholding and snake modeling are implemented based on several image features, such as color contrast, regional color homogeneity and curve bending degree. Next, a 3D model representing the general shape of the food (e.g., a cylinder, a sphere, etc) is selected from a pre-constructed shape model library. The position, orientation and scale of the selected shape model are determined by registering the projected 3D model and the food contour in the image, where the properties of the reference are used as constraints. Experimental results using various realistically shaped foods with known volumes demonstrated satisfactory performance of our image-based food volume measurement method even if the 3D geometric surface of the food is not completely represented in the input image.

  11. Model-based measurement of food portion size for image-based dietary assessment using 3D/2D registration

    PubMed Central

    Chen, Hsin-Chen; Jia, Wenyan; Yue, Yaofeng; Li, Zhaoxin; Sun, Yung-Nien; Fernstrom, John D.; Sun, Mingui

    2013-01-01

    Dietary assessment is important in health maintenance and intervention in many chronic conditions, such as obesity, diabetes, and cardiovascular disease. However, there is currently a lack of convenient methods for measuring the volume of food (portion size) in real-life settings. We present a computational method to estimate food volume from a single photographical image of food contained in a typical dining plate. First, we calculate the food location with respect to a 3D camera coordinate system using the plate as a scale reference. Then, the food is segmented automatically from the background in the image. Adaptive thresholding and snake modeling are implemented based on several image features, such as color contrast, regional color homogeneity and curve bending degree. Next, a 3D model representing the general shape of the food (e.g., a cylinder, a sphere, etc.) is selected from a pre-constructed shape model library. The position, orientation and scale of the selected shape model are determined by registering the projected 3D model and the food contour in the image, where the properties of the reference are used as constraints. Experimental results using various realistically shaped foods with known volumes demonstrated satisfactory performance of our image based food volume measurement method even if the 3D geometric surface of the food is not completely represented in the input image. PMID:24223474

  12. Model-based measurement of food portion size for image-based dietary assessment using 3D/2D registration.

    PubMed

    Chen, Hsin-Chen; Jia, Wenyan; Yue, Yaofeng; Li, Zhaoxin; Sun, Yung-Nien; Fernstrom, John D; Sun, Mingui

    2013-10-01

    Dietary assessment is important in health maintenance and intervention in many chronic conditions, such as obesity, diabetes, and cardiovascular disease. However, there is currently a lack of convenient methods for measuring the volume of food (portion size) in real-life settings. We present a computational method to estimate food volume from a single photographical image of food contained in a typical dining plate. First, we calculate the food location with respect to a 3D camera coordinate system using the plate as a scale reference. Then, the food is segmented automatically from the background in the image. Adaptive thresholding and snake modeling are implemented based on several image features, such as color contrast, regional color homogeneity and curve bending degree. Next, a 3D model representing the general shape of the food (e.g., a cylinder, a sphere, etc.) is selected from a pre-constructed shape model library. The position, orientation and scale of the selected shape model are determined by registering the projected 3D model and the food contour in the image, where the properties of the reference are used as constraints. Experimental results using various realistically shaped foods with known volumes demonstrated satisfactory performance of our image based food volume measurement method even if the 3D geometric surface of the food is not completely represented in the input image.

  13. 3D/2D registration and segmentation of scoliotic vertebrae using statistical models.

    PubMed

    Benameur, Said; Mignotte, Max; Parent, Stefan; Labelle, Hubert; Skalli, Wafa; de Guise, Jacques

    2003-01-01

    We propose a new 3D/2D registration method for vertebrae of the scoliotic spine, using two conventional radiographic views (postero-anterior and lateral), and a priori global knowledge of the geometric structure of each vertebra. This geometric knowledge is efficiently captured by a statistical deformable template integrating a set of admissible deformations, expressed by the first modes of variation in Karhunen-Loeve expansion, of the pathological deformations observed on a representative scoliotic vertebra population. The proposed registration method consists of fitting the projections of this deformable template with the preliminary segmented contours of the corresponding vertebra on the two radiographic views. The 3D/2D registration problem is stated as the minimization of a cost function for each vertebra and solved with a gradient descent technique. Registration of the spine is then done vertebra by vertebra. The proposed method efficiently provides accurate 3D reconstruction of each scoliotic vertebra and, consequently, it also provides accurate knowledge of the 3D structure of the whole scoliotic spine. This registration method has been successfully tested on several biplanar radiographic images and validated on 57 scoliotic vertebrae. The validation results reported in this paper demonstrate that the proposed statistical scheme performs better than other conventional 3D reconstruction methods.

  14. Very fast road database verification using textured 3D city models obtained from airborne imagery

    NASA Astrophysics Data System (ADS)

    Bulatov, Dimitri; Ziems, Marcel; Rottensteiner, Franz; Pohl, Melanie

    2014-10-01

    Road databases are known to be an important part of any geodata infrastructure, e.g. as the basis for urban planning or emergency services. Updating road databases for crisis events must be performed quickly and with the highest possible degree of automation. We present a semi-automatic algorithm for road verification using textured 3D city models, starting from aerial or even UAV-images. This algorithm contains two processes, which exchange input and output, but basically run independently from each other. These processes are textured urban terrain reconstruction and road verification. The first process contains a dense photogrammetric reconstruction of 3D geometry of the scene using depth maps. The second process is our core procedure, since it contains various methods for road verification. Each method represents a unique road model and a specific strategy, and thus is able to deal with a specific type of roads. Each method is designed to provide two probability distributions, where the first describes the state of a road object (correct, incorrect), and the second describes the state of its underlying road model (applicable, not applicable). Based on the Dempster-Shafer Theory, both distributions are mapped to a single distribution that refers to three states: correct, incorrect, and unknown. With respect to the interaction of both processes, the normalized elevation map and the digital orthophoto generated during 3D reconstruction are the necessary input - together with initial road database entries - for the road verification process. If the entries of the database are too obsolete or not available at all, sensor data evaluation enables classification of the road pixels of the elevation map followed by road map extraction by means of vectorization and filtering of the geometrically and topologically inconsistent objects. Depending on the time issue and availability of a geo-database for buildings, the urban terrain reconstruction procedure has semantic models

  15. Geometric Models for Collaborative Search and Filtering

    ERIC Educational Resources Information Center

    Bitton, Ephrat

    2011-01-01

    This dissertation explores the use of geometric and graphical models for a variety of information search and filtering applications. These models serve to provide an intuitive understanding of the problem domains and as well as computational efficiencies to our solution approaches. We begin by considering a search and rescue scenario where both…

  16. Digital structural interpretation of mountain-scale photogrammetric 3D models (Kamnik Alps, Slovenia)

    NASA Astrophysics Data System (ADS)

    Dolžan, Erazem; Vrabec, Marko

    2015-04-01

    From the earliest days of geological science, mountainous terrains with their extreme topographic relief and sparse to non-existent vegetation were utilized to a great advantage for gaining 3D insight into geological structure. But whereas Alpine vistas may offer perfect panoramic views of geology, the steep mountain slopes and vertical cliffs make it very time-consuming and difficult (if not impossible) to acquire quantitative mapping data such as precisely georeferenced traces of geological boundaries and attitudes of structural planes. We faced this problem in mapping the central Kamnik Alps of northern Slovenia, which are built up from Mid to Late Triassic succession of carbonate rocks. Polyphase brittle tectonic evolution, monotonous lithology and the presence of temporally and spatially irregular facies boundary between bedded platform carbonates and massive reef limestones considerably complicate the structural interpretation of otherwise perfectly exposed, but hardly accessible massif. We used Agisoft Photoscan Structure-from-Motion photogrammetric software to process a series of overlapping high-resolution (~0.25 m ground resolution) vertical aerial photographs originally acquired by the Geodetic Authority of the Republic of Slovenia for surveying purposes, to derive very detailed 3D triangular mesh models of terrain and associated photographic textures. Phototextures are crucial for geological interpretation of the models as they provide additional levels of detail and lithological information which is not resolvable from geometrical mesh models alone. We then exported the models to Paradigm Gocad software to refine and optimize the meshing. Structural interpretation of the models, including mapping of traces and surfaces of faults and stratigraphic boundaries and determining dips of structural planes, was performed in MVE Move suite which offers a range of useful tools for digital mapping and interpretation. Photogrammetric model was complemented by

  17. Edge Based 3d Indoor Corridor Modeling Using a Single Image

    NASA Astrophysics Data System (ADS)

    Baligh Jahromi, A.; Sohn, G.

    2015-08-01

    Reconstruction of spatial layout of indoor scenes from a single image is inherently an ambiguous problem. However, indoor scenes are usually comprised of orthogonal planes. The regularity of planar configuration (scene layout) is often recognizable, which provides valuable information for understanding the indoor scenes. Most of the current methods define the scene layout as a single cubic primitive. This domain-specific knowledge is often not valid in many indoors where multiple corridors are linked each other. In this paper, we aim to address this problem by hypothesizing-verifying multiple cubic primitives representing the indoor scene layout. This method utilizes middle-level perceptual organization, and relies on finding the ground-wall and ceiling-wall boundaries using detected line segments and the orthogonal vanishing points. A comprehensive interpretation of these edge relations is often hindered due to shadows and occlusions. To handle this problem, the proposed method introduces virtual rays which aid in the creation of a physically valid cubic structure by using orthogonal vanishing points. The straight line segments are extracted from the single image and the orthogonal vanishing points are estimated by employing the RANSAC approach. Many scene layout hypotheses are created through intersecting random line segments and virtual rays of vanishing points. The created hypotheses are evaluated by a geometric reasoning-based objective function to find the best fitting hypothesis to the image. The best model hypothesis offered with the highest score is then converted to a 3D model. The proposed method is fully automatic and no human intervention is necessary to obtain an approximate 3D reconstruction.

  18. 3D Building Models Segmentation Based on K-Means++ Cluster Analysis

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Mao, B.

    2016-10-01

    3D mesh model segmentation is drawing increasing attentions from digital geometry processing field in recent years. The original 3D mesh model need to be divided into separate meaningful parts or surface patches based on certain standards to support reconstruction, compressing, texture mapping, model retrieval and etc. Therefore, segmentation is a key problem for 3D mesh model segmentation. In this paper, we propose a method to segment Collada (a type of mesh model) 3D building models into meaningful parts using cluster analysis. Common clustering methods segment 3D mesh models by K-means, whose performance heavily depends on randomized initial seed points (i.e., centroid) and different randomized centroid can get quite different results. Therefore, we improved the existing method and used K-means++ clustering algorithm to solve this problem. Our experiments show that K-means++ improves both the speed and the accuracy of K-means, and achieve good and meaningful results.

  19. Combination of Virtual Tours, 3d Model and Digital Data in a 3d Archaeological Knowledge and Information System

    NASA Astrophysics Data System (ADS)

    Koehl, M.; Brigand, N.

    2012-08-01

    The site of the Engelbourg ruined castle in Thann, Alsace, France, has been for some years the object of all the attention of the city, which is the owner, and also of partners like historians and archaeologists who are in charge of its study. The valuation of the site is one of the main objective, as well as its conservation and its knowledge. The aim of this project is to use the environment of the virtual tour viewer as new base for an Archaeological Knowledge and Information System (AKIS). With available development tools we add functionalities in particular through diverse scripts that convert the viewer into a real 3D interface. By beginning with a first virtual tour that contains about fifteen panoramic images, the site of about 150 times 150 meters can be completely documented by offering the user a real interactivity and that makes visualization very concrete, almost lively. After the choice of pertinent points of view, panoramic images were realized. For the documentation, other sets of images were acquired at various seasons and climate conditions, which allow documenting the site in different environments and states of vegetation. The final virtual tour was deducted from them. The initial 3D model of the castle, which is virtual too, was also joined in the form of panoramic images for completing the understanding of the site. A variety of types of hotspots were used to connect the whole digital documentation to the site, including videos (as reports during the acquisition phases, during the restoration works, during the excavations, etc.), digital georeferenced documents (archaeological reports on the various constituent elements of the castle, interpretation of the excavations and the searches, description of the sets of collected objects, etc.). The completely personalized interface of the system allows either to switch from a panoramic image to another one, which is the classic case of the virtual tours, or to go from a panoramic photographic image

  20. A computational framework for 3D mechanical modeling of plant morphogenesis with cellular resolution.

    PubMed

    Boudon, Frédéric; Chopard, Jérôme; Ali, Olivier; Gilles, Benjamin; Hamant, Olivier; Boudaoud, Arezki; Traas, Jan; Godin, Christophe

    2015-01-01

    The link between genetic regulation and the definition of form and size during morphogenesis remains largely an open question in both plant and animal biology. This is partially due to the complexity of the process, involving extensive molecular networks, multiple feedbacks between different scales of organization and physical forces operating at multiple levels. Here we present a conceptual and modeling framework aimed at generating an integrated understanding of morphogenesis in plants. This framework is based on the biophysical properties of plant cells, which are under high internal turgor pressure, and are prevented from bursting because of the presence of a rigid cell wall. To control cell growth, the underlying molecular networks must interfere locally with the elastic and/or plastic extensibility of this cell wall. We present a model in the form of a three dimensional (3D) virtual tissue, where growth depends on the local modulation of wall mechanical properties and turgor pressure. The model shows how forces generated by turgor-pressure can act both cell autonomously and non-cell autonomously to drive growth in different directions. We use simulations to explore lateral organ formation at the shoot apical meristem. Although different scenarios lead to similar shape changes, they are not equivalent and lead to different, testable predictions regarding the mechanical and geometrical properties of the growing lateral organs. Using flower development as an example, we further show how a limited number of gene activities can explain the complex shape changes that accompany organ outgrowth.

  1. A Computational Framework for 3D Mechanical Modeling of Plant Morphogenesis with Cellular Resolution

    PubMed Central

    Gilles, Benjamin; Hamant, Olivier; Boudaoud, Arezki; Traas, Jan; Godin, Christophe

    2015-01-01

    The link between genetic regulation and the definition of form and size during morphogenesis remains largely an open question in both plant and animal biology. This is partially due to the complexity of the process, involving extensive molecular networks, multiple feedbacks between different scales of organization and physical forces operating at multiple levels. Here we present a conceptual and modeling framework aimed at generating an integrated understanding of morphogenesis in plants. This framework is based on the biophysical properties of plant cells, which are under high internal turgor pressure, and are prevented from bursting because of the presence of a rigid cell wall. To control cell growth, the underlying molecular networks must interfere locally with the elastic and/or plastic extensibility of this cell wall. We present a model in the form of a three dimensional (3D) virtual tissue, where growth depends on the local modulation of wall mechanical properties and turgor pressure. The model shows how forces generated by turgor-pressure can act both cell autonomously and non-cell autonomously to drive growth in different directions. We use simulations to explore lateral organ formation at the shoot apical meristem. Although different scenarios lead to similar shape changes, they are not equivalent and lead to different, testable predictions regarding the mechanical and geometrical properties of the growing lateral organs. Using flower development as an example, we further show how a limited number of gene activities can explain the complex shape changes that accompany organ outgrowth. PMID:25569615

  2. Study of the 3D Geometric Structure and Temperature of a Coronal Cavity Using the Limb Synoptic Map Method

    NASA Astrophysics Data System (ADS)

    Karna, N.; Zhang, J.; Pesnell, W. Dean; Hess Webber, S. A.

    2015-09-01

    We present the three-dimensional geometric structure and thermal properties of a coronal cavity deduced from limb synoptic maps. The observations are extreme ultraviolet images from the Atmospheric Imager Assembly (AIA) and magnetic images from the Helioseismic Magnetic Imager instruments on board the Solar Dynamics Observatory. We describe a limb synoptic-map method used to effectively identify and measure cavities from annuli of radiance above the solar limb. We find that cavities are best seen in the 211, 193, and 171 Å passbands. The prominence associated with each cavity is best seen in the 304 Å synoptic maps. We also estimate the thermal properties of the cavity and surrounding plasma by combining the AIA radiances with a differential emission measure analysis. This paper focuses on one long cavity from a catalog of coronal cavities that we are developing. Cavities in this catalog are designated by a coded name using the Carrington Rotation number and position. Cavity C211347177N was observed during Carrington Rotation 2113 at the northwestern limb of the solar disk with an average latitude of 47° N and a central longitude of 177°. We showed the following. (1) The cavity is a long tube with an elliptical cross-section with ratios of the length to width and the length to height of 11:1 and 7:1, respectively. (2) The cavity is about 1360 Mm long, or 170° in longitude. (3) It is tilted in latitude. (4) And it is slightly hotter than its surroundings.

  3. STUDY OF THE 3D GEOMETRIC STRUCTURE AND TEMPERATURE OF A CORONAL CAVITY USING THE LIMB SYNOPTIC MAP METHOD

    SciTech Connect

    Karna, N.; Pesnell, W. Dean; Webber, S. A. Hess; Zhang, J.

    2015-09-10

    We present the three-dimensional geometric structure and thermal properties of a coronal cavity deduced from limb synoptic maps. The observations are extreme ultraviolet images from the Atmospheric Imager Assembly (AIA) and magnetic images from the Helioseismic Magnetic Imager instruments on board the Solar Dynamics Observatory. We describe a limb synoptic-map method used to effectively identify and measure cavities from annuli of radiance above the solar limb. We find that cavities are best seen in the 211, 193, and 171 Å passbands. The prominence associated with each cavity is best seen in the 304 Å synoptic maps. We also estimate the thermal properties of the cavity and surrounding plasma by combining the AIA radiances with a differential emission measure analysis. This paper focuses on one long cavity from a catalog of coronal cavities that we are developing. Cavities in this catalog are designated by a coded name using the Carrington Rotation number and position. Cavity C211347177N was observed during Carrington Rotation 2113 at the northwestern limb of the solar disk with an average latitude of 47° N and a central longitude of 177°. We showed the following. (1) The cavity is a long tube with an elliptical cross-section with ratios of the length to width and the length to height of 11:1 and 7:1, respectively. (2) The cavity is about 1360 Mm long, or 170° in longitude. (3) It is tilted in latitude. (4) And it is slightly hotter than its surroundings.

  4. Enhanced RGB-D Mapping Method for Detailed 3D Indoor and Outdoor Modeling

    PubMed Central

    Tang, Shengjun; Zhu, Qing; Chen, Wu; Darwish, Walid; Wu, Bo; Hu, Han; Chen, Min

    2016-01-01

    RGB-D sensors (sensors with RGB camera and Depth camera) are novel sensing systems that capture RGB images along with pixel-wise depth information. Although they are widely used in various applications, RGB-D sensors have significant drawbacks including limited measurement ranges (e.g., within 3 m) and errors in depth measurement increase with distance from the sensor with respect to 3D dense mapping. In this paper, we present a novel approach to geometrically integrate the depth scene and RGB scene to enlarge the measurement distance of RGB-D sensors and enrich the details of model generated from depth images. First, precise calibration for RGB-D Sensors is introduced. In addition to the calibration of internal and external parameters for both, IR camera and RGB camera, the relative pose between RGB camera and IR camera is also calibrated. Second, to ensure poses accuracy of RGB images, a refined false features matches rejection method is introduced by combining the depth information and initial camera poses between frames of the RGB-D sensor. Then, a global optimization model is used to improve the accuracy of the camera pose, decreasing the inconsistencies between the depth frames in advance. In order to eliminate the geometric inconsistencies between RGB scene and depth scene, the scale ambiguity problem encountered during the pose estimation with RGB image sequences can be resolved by integrating the depth and visual information and a robust rigid-transformation recovery method is developed to register RGB scene to depth scene. The benefit of the proposed joint optimization method is firstly evaluated with the publicly available benchmark datasets collected with Kinect. Then, the proposed method is examined by tests with two sets of datasets collected in both outside and inside environments. The experimental results demonstrate the feasibility and robustness of the proposed method. PMID:27690028

  5. Enhanced RGB-D Mapping Method for Detailed 3D Indoor and Outdoor Modeling.

    PubMed

    Tang, Shengjun; Zhu, Qing; Chen, Wu; Darwish, Walid; Wu, Bo; Hu, Han; Chen, Min

    2016-09-27

    RGB-D sensors (sensors with RGB camera and Depth camera) are novel sensing systems that capture RGB images along with pixel-wise depth information. Although they are widely used in various applications, RGB-D sensors have significant drawbacks including limited measurement ranges (e.g., within 3 m) and errors in depth measurement increase with distance from the sensor with respect to 3D dense mapping. In this paper, we present a novel approach to geometrically integrate the depth scene and RGB scene to enlarge the measurement distance of RGB-D sensors and enrich the details of model generated from depth images. First, precise calibration for RGB-D Sensors is introduced. In addition to the calibration of internal and external parameters for both, IR camera and RGB camera, the relative pose between RGB camera and IR camera is also calibrated. Second, to ensure poses accuracy of RGB images, a refined false features matches rejection method is introduced by combining the depth information and initial camera poses between frames of the RGB-D sensor. Then, a global optimization model is used to improve the accuracy of the camera pose, decreasing the inconsistencies between the depth frames in advance. In order to eliminate the geometric inconsistencies between RGB scene and depth scene, the scale ambiguity problem encountered during the pose estimation with RGB image sequences can be resolved by integrating the depth and visual information and a robust rigid-transformation recovery method is developed to register RGB scene to depth scene. The benefit of the proposed joint optimization method is firstly evaluated with the publicly available benchmark datasets collected with Kinect. Then, the proposed method is examined by tests with two sets of datasets collected in both outside and inside environments. The experimental results demonstrate the feasibility and robustness of the proposed method.

  6. Comparing thin-sheet models with 3-D multilayer models for continental collision

    NASA Astrophysics Data System (ADS)

    Lechmann, S. M.; May, D. A.; Kaus, B. J. P.; Schmalholz, S. M.

    2011-10-01

    Various models have been proposed to explain tectonic deformations during continent collision. A frequently applied model is the thin viscous sheet model which is however not fully 3-D and assumes a priori diffuse thickening as the dominant deformation style. We compare a fully 3-D multilayer numerical model with a corresponding thin viscous sheet numerical model for the scenario of continent indentation. In our comparison we focus on the three basic viscous deformation styles thickening, buckling (folding) and lateral crustal flow. Both numerical models are based on the finite element method (FEM) and employ either a linear or power-law viscous rheology. The 3-D model consists of four layers representing a simplified continental lithosphere: strong upper crust, weak lower crust, strong upper mantle and weak lower mantle. The effective viscosity depth-profile in the 3-D model is used to calculate the depth-averaged effective viscosity used in the thin-sheet model allowing a direct comparison of both models. We quantify the differences in the strain rate and velocity fields, and investigate the evolution of crustal thickening, buckling and crustal flow resulting from the two models for two different phases of deformation: (1) indentation with a constant velocity and (2) gravitational collapse after a decrease of the indenting velocity by a factor of 5. The results indicate that thin-sheet models approximate well the overall large-scale lithospheric deformation, especially during indentation and for a linear viscous rheology. However, in the 3-D model, additional processes such as multilayer buckling and lower crustal flow emerge, which are ignored in the thin-sheet model but dominate the deformation style in the 3-D model within a range of a few hundreds of kilometres around the collision zone and indenter corner. Differences between the 3-D and thin-sheet model are considerably larger for a power-law viscous than for a linear viscous rheology. Buckling and lower

  7. Initial Comparison Between a 3D MHD Model and the HAFv2 Kinematic 3D Model: The October/November 2003 Events from the Sun to 6 AU

    SciTech Connect

    Intriligator, Devrie S.; Detman, Thomas; Fry, Craig D.; Sun Wei; Deehr, Charles; Intriligator, James

    2005-08-01

    A first-generation 3D kinematic, space weather forecasting solar wind model (HAFv2) has been used to show the importance of solar generated disturbances in Voyager 1 and Voyager 2 observations in the outer heliosphere. We extend this work by using a 3D MHD model (HHMS) that, like HAFv2, incorporates a global, pre-event, inhomogeneous, background solar wind plasma and interplanetary magnetic field. Initial comparisons are made between the two models of the solar wind out to 6 AU and with in-situ observations at the ACE spacecraft before and after the October/November 2003 solar events.

  8. [3-D endocardial surface modelling based on the convex hull algorithm].

    PubMed

    Lu, Ying; Xi, Ri-hui; Shen, Hai-dong; Ye, You-li; Zhang, Yong

    2006-11-01

    In this paper, a method based on the convex hull algorithm is presented for extracting modelling data from the locations of catheter electrodes within a cardiac chamber, so as to create a 3-D model of the heart chamber during diastole and to obtain a good result in the 3-D reconstruction of the chamber based on VTK.

  9. Rethinking Design Process: Using 3D Digital Models as an Interface in Collaborative Session

    ERIC Educational Resources Information Center

    Ding, Suining

    2008-01-01

    This paper describes a pilot study for an alternative design process by integrating a designer-user collaborative session with digital models. The collaborative session took place in a 3D AutoCAD class for a real world project. The 3D models served as an interface for designer-user collaboration during the design process. Students not only learned…

  10. 3D Modeling from Multi-views Images for Cultural Heritage in Wat-Pho, Thailand

    NASA Astrophysics Data System (ADS)

    Soontranon, N.; Srestasathiern, P.; Lawawirojwong, S.

    2015-08-01

    In Thailand, there are several types of (tangible) cultural heritages. This work focuses on 3D modeling of the heritage objects from multi-views images. The images are acquired by using a DSLR camera which costs around 1,500 (camera and lens). Comparing with a 3D laser scanner, the camera is cheaper and lighter than the 3D scanner. Hence, the camera is available for public users and convenient for accessing narrow areas. The acquired images consist of various sculptures and architectures in Wat-Pho which is a Buddhist temple located behind the Grand Palace (Bangkok, Thailand). Wat-Pho is known as temple of the reclining Buddha and the birthplace of traditional Thai massage. To compute the 3D models, a diagram is separated into following steps; Data acquisition, Image matching, Image calibration and orientation, Dense matching and Point cloud processing. For the initial work, small heritages less than 3 meters height are considered for the experimental results. A set of multi-views images of an interested object is used as input data for 3D modeling. In our experiments, 3D models are obtained from MICMAC (open source) software developed by IGN, France. The output of 3D models will be represented by using standard formats of 3D point clouds and triangulated surfaces such as .ply, .off, .obj, etc. To compute for the efficient 3D models, post-processing techniques are required for the final results e.g. noise reduction, surface simplification and reconstruction. The reconstructed 3D models can be provided for public access such as website, DVD, printed materials. The high accurate 3D models can also be used as reference data of the heritage objects that must be restored due to deterioration of a lifetime, natural disasters, etc.

  11. 2D fluid model analysis for the effect of 3D gas flow on a capacitively coupled plasma deposition reactor

    NASA Astrophysics Data System (ADS)

    Kim, Ho Jun; Lee, Hae June

    2016-06-01

    The wide applicability of capacitively coupled plasma (CCP) deposition has increased the interest in developing comprehensive numerical models, but CCP imposes a tremendous computational cost when conducting a transient analysis in a three-dimensional (3D) model which reflects the real geometry of reactors. In particular, the detailed flow features of reactive gases induced by 3D geometric effects need to be considered for the precise calculation of radical distribution of reactive species. Thus, an alternative inclusive method for the numerical simulation of CCP deposition is proposed to simulate a two-dimensional (2D) CCP model based on the 3D gas flow results by simulating flow, temperature, and species fields in a 3D space at first without calculating the plasma chemistry. A numerical study of a cylindrical showerhead-electrode CCP reactor was conducted for particular cases of SiH4/NH3/N2/He gas mixture to deposit a hydrogenated silicon nitride (SiN x H y ) film. The proposed methodology produces numerical results for a 300 mm wafer deposition reactor which agree very well with the deposition rate profile measured experimentally along the wafer radius.

  12. Computational 3-D Model of the Human Respiratory System

    EPA Science Inventory

    We are developing a comprehensive, morphologically-realistic computational model of the human respiratory system that can be used to study the inhalation, deposition, and clearance of contaminants, while being adaptable for age, race, gender, and health/disease status. The model ...

  13. A topological framework for interactive queries on 3D models in the Web.

    PubMed

    Figueiredo, Mauro; Rodrigues, José I; Silvestre, Ivo; Veiga-Pires, Cristina

    2014-01-01

    Several technologies exist to create 3D content for the web. With X3D, WebGL, and X3DOM, it is possible to visualize and interact with 3D models in a web browser. Frequently, three-dimensional objects are stored using the X3D file format for the web. However, there is no explicit topological information, which makes it difficult to design fast algorithms for applications that require adjacency and incidence data. This paper presents a new open source toolkit TopTri (Topological model for Triangle meshes) for Web3D servers that builds the topological model for triangular meshes of manifold or nonmanifold models. Web3D client applications using this toolkit make queries to the web server to get adjacent and incidence information of vertices, edges, and faces. This paper shows the application of the topological information to get minimal local points and iso-lines in a 3D mesh in a web browser. As an application, we present also the interactive identification of stalactites in a cave chamber in a 3D web browser. Several tests show that even for large triangular meshes with millions of triangles, the adjacency and incidence information is returned in real time making the presented toolkit appropriate for interactive Web3D applications.

  14. Use of 3D Printed Models in Medical Education: A Randomized Control Trial Comparing 3D Prints versus Cadaveric Materials for Learning External Cardiac Anatomy

    ERIC Educational Resources Information Center

    Lim, Kah Heng Alexander; Loo, Zhou Yaw; Goldie, Stephen J.; Adams, Justin W.; McMenamin, Paul G.

    2016-01-01

    Three-dimensional (3D) printing is an emerging technology capable of readily producing accurate anatomical models, however, evidence for the use of 3D prints in medical education remains limited. A study was performed to assess their effectiveness against cadaveric materials for learning external cardiac anatomy. A double blind randomized…

  15. Inspection, 3D modelling, and rapid prototyping of cultural heritage by means of a 3D optical digitiser

    NASA Astrophysics Data System (ADS)

    Docchio, F.; Sansoni, G.; Trebeschi, M.

    2005-06-01

    This paper presents the activity carried out to perform the three-dimensional acquisition of the "Vittoria Alata", a 2m-high, bronze statue, symbol of our City, located at the Civici Musei di Arte e Storia (S. Giulia) of Brescia. The acquisition of the statue has been performed by using a three-dimensional vision system based on active triangulation and on the projection of non-coherent light. This system, called OPL-3D, represents one of the research products of our Laboratory, which has been active for years in the development of techniques and systems for the contactless acquisition of free-form, complex shapes. The study, originally motivated by the need to explore a new hypothesis on the origin of the "Vittoria Alata", led to its complete digitization and description in terms of both polygonal and NURBS-based models. A suite of copies of the whole statue has been obtained in the framework of the collaboration between the City Museum and the EOS Electro Optical Systems GmbH, located in Munich, Germany. As a first step, one 30 cm-high replica of the whole statue has been produced using a low-resolution triangle model of the statue (3.5 millions of triangles). As a second step, two 1:1 scale copies of the statue have been produced. For them, the Laboratory has provided the high resolution STL file (16 millions of triangles). The paper discusses in detail the hardware and the software facilities used to implement the whole process, and gives a comprehensive description of the results.

  16. Determination of HCME 3-D parameters using a full ice-cream cone model

    NASA Astrophysics Data System (ADS)

    Na, Hyeonock; Moon, Yong-Jae; Lee, Harim

    2016-05-01

    It is very essential to determine three dimensional parameters (e.g., radial speed, angular width, source location) of Coronal Mass Ejections (CMEs) for space weather forecast. Several cone models (e.g., an elliptical cone model, an ice-cream cone model, an asymmetric cone model) have been examined to estimate these parameters. In this study, we investigate which cone type is close to a halo CME morphology using 26 CMEs: halo CMEs by one spacecraft (SOHO or STEREO-A or B) and as limb CMEs by the other ones. From cone shape parameters of these CMEs such as their front curvature, we find that near full ice-cream cone type CMEs are much closer to observations than shallow ice-cream cone type CMEs. Thus we develop a new cone model in which a full ice-cream cone consists of many flat cones with different heights and angular widths. This model is carried out by the following steps: (1) construct a cone for given height and angular width, (2) project the cone onto the sky plane, (3) select points comprising the outer boundary, and (4) minimize the difference between the estimated projection speeds with the observed ones. By applying this model to 12 SOHO/LASCO halo CMEs, we find that 3-D parameters from our method are similar to those from other stereoscopic methods (a geometrical triangulation method and a Graduated Cylindrical Shell model) based on multi-spacecraft data. We are developing a general ice-cream cone model whose front shape is a free parameter determined by observations.

  17. Assessing a 3D smoothed seismicity model of induced earthquakes

    NASA Astrophysics Data System (ADS)

    Zechar, Jeremy; Király, Eszter; Gischig, Valentin; Wiemer, Stefan

    2016-04-01

    As more energy exploration and extraction efforts cause earthquakes, it becomes increasingly important to control induced seismicity. Risk management schemes must be improved and should ultimately be based on near-real-time forecasting systems. With this goal in mind, we propose a test bench to evaluate models of induced seismicity based on metrics developed by the CSEP community. To illustrate the test bench, we consider a model based on the so-called seismogenic index and a rate decay; to produce three-dimensional forecasts, we smooth past earthquakes in space and time. We explore four variants of this model using the Basel 2006 and Soultz-sous-Forêts 2004 datasets to make short-term forecasts, test their consistency, and rank the model variants. Our results suggest that such a smoothed seismicity model is useful for forecasting induced seismicity within three days, and giving more weight to recent events improves forecast performance. Moreover, the location of the largest induced earthquake is forecast well by this model. Despite the good spatial performance, the model does not estimate the seismicity rate well: it frequently overestimates during stimulation and during the early post-stimulation period, and it systematically underestimates around shut-in. In this presentation, we also describe a robust estimate of information gain, a modification that can also benefit forecast experiments involving tectonic earthquakes.

  18. Constructing stable 3D hydrodynamical models of giant stars

    NASA Astrophysics Data System (ADS)

    Ohlmann, Sebastian T.; Röpke, Friedrich K.; Pakmor, Rüdiger; Springel, Volker

    2017-02-01

    Hydrodynamical simulations of stellar interactions require stable models of stars as initial conditions. Such initial models, however, are difficult to construct for giant stars because of the wide range in spatial scales of the hydrostatic equilibrium and in dynamical timescales between the core and the envelope of the giant. They are needed for, e.g., modeling the common envelope phase where a giant envelope encompasses both the giant core and a companion star. Here, we present a new method of approximating and reconstructing giant profiles from a stellar evolution code to produce stable models for multi-dimensional hydrodynamical simulations. We determine typical stellar stratification profiles with the one-dimensional stellar evolution code mesa. After an appropriate mapping, hydrodynamical simulations are conducted using the moving-mesh code arepo. The giant profiles are approximated by replacing the core of the giant with a point mass and by constructing a suitable continuation of the profile to the center. Different reconstruction methods are tested that can specifically control the convective behaviour of the model. After mapping to a grid, a relaxation procedure that includes damping of spurious velocities yields stable models in three-dimensional hydrodynamical simulations. Initially convectively stable configurations lead to stable hydrodynamical models while for stratifications that are convectively unstable in the stellar evolution code, simulations recover the convective behaviour of the initial model and show large convective plumes with Mach numbers up to 0.8. Examples are shown for a 2 M⊙ red giant and a 0.67 M⊙ asymptotic giant branch star. A detailed analysis shows that the improved method reliably provides stable models of giant envelopes that can be used as initial conditions for subsequent hydrodynamical simulations of stellar interactions involving giant stars.

  19. Nonlinear Multiscale Modeling of 3D Woven Fiber Composites under Ballistic Loading

    DTIC Science & Technology

    2013-07-11

    advanced composites like 3D -OWC. On the other hand, a microscale simulation with resolution of individual fiber filament is impractical due to enormous...REPORT Nonlinear Multiscale Modeling of 3D Woven Fiber Composites under Ballistic Loading 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: The objective of...analysis of 3D woven fiber composites under ballistic loading. Since material behavior is determined by its microstructure, it is essential to

  20. Services Oriented Smart City Platform Based On 3d City Model Visualization

    NASA Astrophysics Data System (ADS)

    Prandi, F.; Soave, M.; Devigili, F.; Andreolli, M.; De Amicis, R.

    2014-04-01

    The rapid technological evolution, which is characterizing all the disciplines involved within the wide concept of smart cities, is becoming a key factor to trigger true user-driven innovation. However to fully develop the Smart City concept to a wide geographical target, it is required an infrastructure that allows the integration of heterogeneous geographical information and sensor networks into a common technological ground. In this context 3D city models will play an increasingly important role in our daily lives and become an essential part of the modern city information infrastructure (Spatial Data Infrastructure). The work presented in this paper describes an innovative Services Oriented Architecture software platform aimed at providing smartcities services on top of 3D urban models. 3D city models are the basis of many applications and can became the platform for integrating city information within the Smart-Cites context. In particular the paper will investigate how the efficient visualisation of 3D city models using different levels of detail (LODs) is one of the pivotal technological challenge to support Smart-Cities applications. The goal is to provide to the final user realistic and abstract 3D representations of the urban environment and the possibility to interact with a massive amounts of semantic information contained into the geospatial 3D city model. The proposed solution, using OCG standards and a custom service to provide 3D city models, lets the users to consume the services and interact with the 3D model via Web in a more effective way.

  1. Synthesis of image sequences for Korean sign language using 3D shape model

    NASA Astrophysics Data System (ADS)

    Hong, Mun-Ho; Choi, Chang-Seok; Kim, Chang-Seok; Jeon, Joon-Hyeon

    1995-05-01

    This paper proposes a method for offering information and realizing communication to the deaf-mute. The deaf-mute communicates with another person by means of sign language, but most people are unfamiliar with it. This method enables to convert text data into the corresponding image sequences for Korean sign language (KSL). Using a general 3D shape model of the upper body leads to generating the 3D motions of KSL. It is necessary to construct the general 3D shape model considering the anatomical structure of the human body. To obtain a personal 3D shape model, this general model is to adjust to the personal base images. Image synthesis for KSL consists of deforming a personal 3D shape model and texture-mapping the personal images onto the deformed model. The 3D motions for KSL have the facial expressions and the 3D movements of the head, trunk, arms and hands and are parameterized for easily deforming the model. These motion parameters of the upper body are extracted from a skilled signer's motion for each KSL and are stored to the database. Editing the parameters according to the inputs of text data yields to generate the image sequences of 3D motions.

  2. 3-D Constraint-Based Modeling: Finding Common Themes.

    ERIC Educational Resources Information Center

    Wiebe, Eric N.

    1999-01-01

    Uses Shneiderman's Object-Action Interface model along with the engineering design process as a framework for understanding software interface elements. Provides an educational framework from which instructional materials can be developed. (Author/CCM)

  3. 3D modelling of facade features on large sites acquired by vehicle based laser scanning

    NASA Astrophysics Data System (ADS)

    Boulaassal, H.; Landes, T.; Grussenmeyer, P.

    2011-12-01

    Mobile mapping laser scanning systems have become more and more widespread for the acquisition of millions of 3D points on large and geometrically complex urban sites. Vehicle-based Laser Scanning (VLS) systems travel many kilometers while acquiring raw point clouds which are registered in real time in a common coordinate system. Improvements of the acquisition steps as well as the automatic processing of the collected point clouds are still a conundrum for researchers. This paper shows some results obtained by application, on mobile laser scanner data, of segmentation and reconstruction algorithms intended initially to generate individual vector facade models using stationary Terrestrial Laser Scanner (TLS) data. The operating algorithms are adapted so as to take into account characteristics of VLS data. The intrinsic geometry of a point cloud as well as the relative geometry between registered point clouds are different from that obtained by a static TLS. The amount of data provided by this acquisition technique is another issue. Such particularities should be taken into consideration while processing this type of point clouds. The segmentation of VLS data is carried out based on an adaptation of RANSAC algorithm. Edge points of each element are extracted by applying a second algorithm. Afterwards, the vector models of each facade element are reconstructed. In order to validate the results, large samples with different characteristics have been introduced in the developed processing chain. The limitations as well as the capabilities of each process will be emphasized in terms of geometry and processing time.

  4. Cycle graph analysis for 3D roof structure modelling: Concepts and performance

    NASA Astrophysics Data System (ADS)

    Perera, Gamage Sanka Nirodha; Maas, Hans-Gerd

    2014-07-01

    The paper presents a cycle graph analysis approach to the automatic reconstruction of 3D roof models from airborne laser scanner data. The nature of convergences of topological relations of plane adjacencies, allowing for the reconstruction of roof corner geometries with preserved topology, can be derived from cycles in roof topology graphs. The topology between roof adjacencies is defined in terms of ridge-lines and step-edges. In the proposed method, the input point cloud is first segmented and roof topology is derived while extracting roof planes from identified non-terrain segments. Orientation and placement regularities are applied on weakly defined edges using a piecewise regularization approach prior to the reconstruction, which assists in preserving symmetries in building geometry. Roof corners are geometrically modelled using the shortest closed cycles and the outermost cycle derived from roof topology graph in which external target graphs are no longer required. Based on test results, we show that the proposed approach can handle complexities with nearly 90% of the detected roof faces reconstructed correctly. The approach allows complex height jumps and various types of building roofs to be firmly reconstructed without prior knowledge of primitive building types.

  5. Automated mask creation from a 3D model using Faethm.

    SciTech Connect

    Schiek, Richard Louis; Schmidt, Rodney Cannon

    2007-11-01

    We have developed and implemented a method which given a three-dimensional object can infer from topology the two-dimensional masks needed to produce that object with surface micro-machining. The masks produced by this design tool can be generic, process independent masks, or if given process constraints, specific for a target process. This design tool calculates the two-dimensional mask set required to produce a given three-dimensional model by investigating the vertical topology of the model.

  6. Pluto: Modeling of 3-D Atmosphere-Surface Interactions

    NASA Astrophysics Data System (ADS)

    Michaels, Timothy I.

    2015-11-01

    Atmosphere-surface interactions on Pluto are of great importance to creating and maintaining the atmospheric variations and heterogeneous surface that have been observed by New Horizons and two decades' prior work. Publicly released images/data from New Horizons contain numerous fascinating surface features and constrasts. Insights into their origin, maintenance, and/or evolution may be gleaned through multidisciplinary climate modeling. Some results from such modeling will be presented, with an emphasis on shorter-timescale interactions.

  7. Computational ocean acoustics: Advances in 3D ocean acoustic modeling

    NASA Astrophysics Data System (ADS)

    Schmidt, Henrik; Jensen, Finn B.

    2012-11-01

    The numerical model of ocean acoustic propagation developed in the 1980's are still in widespread use today, and the field of computational ocean acoustics is often considered a mature field. However, the explosive increase in computational power available to the community has created opportunities for modeling phenomena that earlier were beyond reach. Most notably, three-dimensional propagation and scattering problems have been prohibitive computationally, but are now addressed routinely using brute force numerical approaches such as the Finite Element Method, in particular for target scattering problems, where they are being combined with the traditional wave theory propagation