WorldWideScience

Sample records for 3d topology preserving

  1. Topology dictionary for 3D video understanding.

    Science.gov (United States)

    Tung, Tony; Matsuyama, Takashi

    2012-08-01

    This paper presents a novel approach that achieves 3D video understanding. 3D video consists of a stream of 3D models of subjects in motion. The acquisition of long sequences requires large storage space (2 GB for 1 min). Moreover, it is tedious to browse data sets and extract meaningful information. We propose the topology dictionary to encode and describe 3D video content. The model consists of a topology-based shape descriptor dictionary which can be generated from either extracted patterns or training sequences. The model relies on 1) topology description and classification using Reeb graphs, and 2) a Markov motion graph to represent topology change states. We show that the use of Reeb graphs as the high-level topology descriptor is relevant. It allows the dictionary to automatically model complex sequences, whereas other strategies would require prior knowledge on the shape and topology of the captured subjects. Our approach serves to encode 3D video sequences, and can be applied for content-based description and summarization of 3D video sequences. Furthermore, topology class labeling during a learning process enables the system to perform content-based event recognition. Experiments were carried out on various 3D videos. We showcase an application for 3D video progressive summarization using the topology dictionary.

  2. Topology Dictionary for 3D Video Understanding

    OpenAIRE

    2012-01-01

    This paper presents a novel approach that achieves 3D video understanding. 3D video consists of a stream of 3D models of subjects in motion. The acquisition of long sequences requires large storage space (2 GB for 1 min). Moreover, it is tedious to browse data sets and extract meaningful information. We propose the topology dictionary to encode and describe 3D video content. The model consists of a topology-based shape descriptor dictionary which can be generated from either extracted pattern...

  3. Factorising the 3D Topologically Twisted Index

    CERN Document Server

    Cabo-Bizet, Alejandro

    2016-01-01

    In this work, path integral representations of the 3D topologically twisted index were studied. First, the index can be "factorised" into a couple of "blocks". The "blocks" being the partition functions of a type A semi-topological twisting of 3D N = 2 SYM placed on $\\mathbb{S}_2\\times (0, \\pi)$ and $\\mathbb{S}_2 \\times (\\pi, 2 \\pi)$ respectively. Second, as the path integral of the aforementioned theory over $\\mathbb{S}_2$ times $\\mathbb{S}_1$ with a point excluded. In this way we recover the sum over fluxes from integration over the real path and without sacrificing positive definiteness of the bosonic part of the localising action. We also reproduce the integration over the complex contour by using the localising term with positive definite bosonic part.

  4. Surface Plasmons in 3D Topological Insulators

    Science.gov (United States)

    Kogar, Anshul; Vig, Sean; Cho, Gil; Thaler, Alexander; Xiao, Yiran; Hughes, Taylor; Wong, Man-Hong; Chiang, Tai-Chang; MacDougall, Greg; Abbamonte, Peter

    2015-03-01

    Most studies of three-dimensional (3D) topological insulators have concentrated on their one-electron properties as exhibited by angle-resolved photoemission spectroscopy (ARPES) or by scanning tunneling microscopy (STM). Many-body interactions are often neglected in the treatment of models of topological insulators, such as in the Kane-Mele and Bernevig-Hughes-Zhang models. Using angle-resolved inelastic electron scattering from the surface, I will present data on the collective mode that owes its existence to the presence of many-body interactions, the surface plasmon (SP), in two known 3D topological insulators, Bi2Se3 and Bi0.5Sb1.5Se1 . 5 + xTe1 . 5 - x. Surprisingly, the SP was prominent even after depressing the Fermi energy into the bulk band gap. Having studied the SP as a function of doping, momentum transfer and its aging properties, I will present evidence to suggest that bulk-surface coupling is crucial in explaining many of its properties. A simple model with dynamic bulk screening will be presented showing qualitative agreement with the observations. Lastly, the relation of the observed surface plasmon to the predicted spin-plasmon mode and to the kinks seen in the electronic dispersion as measured by ARPES will be discussed. The work was supported as part of the Center for Emergent Superconductivity, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science.

  5. A symmetry-respecting topologically-ordered surface phase of 3d electron topological insulators

    OpenAIRE

    Metlitski, Max A.; Kane, C. L.; Fisher, Matthew P. A.

    2013-01-01

    A 3d electron topological insulator (ETI) is a phase of matter protected by particle-number conservation and time-reversal symmetry. It was previously believed that the surface of an ETI must be gapless unless one of these symmetries is broken. A well-known symmetry-preserving, gapless surface termination of an ETI supports an odd number of Dirac cones. In this paper we deduce a symmetry-respecting, gapped surface termination of an ETI, which carries an intrinsic 2d topological order, Moore-R...

  6. Tracking topological entity changes in 3D collaborative modeling systems

    Institute of Scientific and Technical Information of China (English)

    ChengYuan; He Fazhi; HuangZhiyong; Cai Xiantao; and Zhang Dejun

    2012-01-01

    One of the key problems in collaborative geometric modeling systems is topological entity correspondence when topolog- ical structure of geometry models on collaborative sites changes, ha this article, we propose a solution for tracking topological entity alterations in 3D collaborative modeling environment. We firstly make a thorough analysis and detailed categorization on the altera- tion properties and causations for each type of topological entity, namely topological face and topological edge. Based on collabora- tive topological entity naming mechanism, a data structure called TEST (Topological Entity Structure Tree) is introduced to track the changing history and current state of each topological entity, to embody the relationship among topological entities. Rules and algo- rithms are presented for identification of topological entities referenced by operations for correct execution and model consistency. The algorithm has been verified within the prototype we have implemented with ACIS.

  7. DESIGN OF 3D TOPOLOGICAL DATA STRUCTURE FOR 3D CADASTRE OBJECTS

    Directory of Open Access Journals (Sweden)

    N. A. Zulkifli

    2016-09-01

    Full Text Available This paper describes the design of 3D modelling and topological data structure for cadastre objects based on Land Administration Domain Model (LADM specifications. Tetrahedral Network (TEN is selected as a 3D topological data structure for this project. Data modelling is based on the LADM standard and it is used five classes (i.e. point, boundary face string, boundary face, tetrahedron and spatial unit. This research aims to enhance the current cadastral system by incorporating 3D topology model based on LADM standard.

  8. Design of 3d Topological Data Structure for 3d Cadastre Objects

    Science.gov (United States)

    Zulkifli, N. A.; Rahman, A. Abdul; Hassan, M. I.

    2016-09-01

    This paper describes the design of 3D modelling and topological data structure for cadastre objects based on Land Administration Domain Model (LADM) specifications. Tetrahedral Network (TEN) is selected as a 3D topological data structure for this project. Data modelling is based on the LADM standard and it is used five classes (i.e. point, boundary face string, boundary face, tetrahedron and spatial unit). This research aims to enhance the current cadastral system by incorporating 3D topology model based on LADM standard.

  9. Time domain topology optimization of 3D nanophotonic devices

    DEFF Research Database (Denmark)

    Elesin, Yuriy; Lazarov, Boyan Stefanov; Jensen, Jakob Søndergaard;

    2014-01-01

    We present an efficient parallel topology optimization framework for design of large scale 3D nanophotonic devices. The code shows excellent scalability and is demonstrated for optimization of broadband frequency splitter, waveguide intersection, photonic crystal-based waveguide and nanowire...

  10. Method for 3D Airway Topology Extraction

    Directory of Open Access Journals (Sweden)

    Roman Grothausmann

    2015-01-01

    Full Text Available In lungs the number of conducting airway generations as well as bifurcation patterns varies across species and shows specific characteristics relating to illnesses or gene variations. A method to characterize the topology of the mouse airway tree using scanning laser optical tomography (SLOT tomograms is presented in this paper. It is used to test discrimination between two types of mice based on detected differences in their conducting airway pattern. Based on segmentations of the airways in these tomograms, the main spanning tree of the volume skeleton is computed. The resulting graph structure is used to distinguish between wild type and surfactant protein (SP-D deficient knock-out mice.

  11. Topology optimization of 3D shell structures with porous infill

    DEFF Research Database (Denmark)

    Clausen, Anders; Andreassen, Erik; Sigmund, Ole

    2017-01-01

    This paper presents a 3D topology optimization approach for designing shell structures with a porous or void interior. It is shown that the resulting structures are significantly more robust towards load perturbations than completely solid structures optimized under the same conditions. The study...... indicates that the potential benefit of using porous structures is higher for lower total volume fractions. Compared to earlier work dealing with 2D topology optimization, we found several new effects in 3D problems. Most notably, the opportunity for designing closed shells significantly improves...

  12. Reconnection experiments with 3D magnetic nulls in different topologies

    Science.gov (United States)

    Vrublevskis, A.; Egedal, J.; Le, A.

    2012-10-01

    Magnetic reconnection has been predominantly investigated in two dimensions. However, depending on the topology and geometry of the magnetic field, a rich collection of magnetic reconnection scenarios is possible in 3D including reconnection at magnetic nulls. At the Versatile Toroidal Facility (VTF) we have implemented a new magnetic geometry with a pair of 3D null points in the background toroidal field. We form a flux rope along the background field and observe it to rapidly restructure and rewire as the nulls develop. We can adjust the topology of the configuration from one where a field line connects the nulls to one where the nulls are no longer linked. A suit of diagnostics will be deployed and results presented for how the topology affects the dynamics of the flux rope.

  13. An Automated 3d Indoor Topological Navigation Network Modelling

    Science.gov (United States)

    Jamali, A.; Rahman, A. A.; Boguslawski, P.; Gold, C. M.

    2015-10-01

    Indoor navigation is important for various applications such as disaster management and safety analysis. In the last decade, indoor environment has been a focus of wide research; that includes developing techniques for acquiring indoor data (e.g. Terrestrial laser scanning), 3D indoor modelling and 3D indoor navigation models. In this paper, an automated 3D topological indoor network generated from inaccurate 3D building models is proposed. In a normal scenario, 3D indoor navigation network derivation needs accurate 3D models with no errors (e.g. gap, intersect) and two cells (e.g. rooms, corridors) should touch each other to build their connections. The presented 3D modeling of indoor navigation network is based on surveying control points and it is less dependent on the 3D geometrical building model. For reducing time and cost of indoor building data acquisition process, Trimble LaserAce 1000 as surveying instrument is used. The modelling results were validated against an accurate geometry of indoor building environment which was acquired using Trimble M3 total station.

  14. Topology optimization of 3D Stokes flow problems

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Allan; Sigmund, Ole; Bendsøe, Martin P.

    examples relevant for optimal micro fluidic mixer design are shown where the design is planar - compliant with micro fabrication techniques - and where the designs are 3D. In addition issues related to the parallel solution of the linear algebra problems are discussed. The implementation uses...... the commercial COMSOL multiphysics programme which is sufficiently flexible to provide semi--automated analytical sensitivities. 1. M. P. Bendsoe and O. Sigmund, "Topology Optimization - Theory, Methods and Applications", Springer Verlag, Berlin Heidelberg, 2003. 2. T. Borrvall and J. Petersson, "Topology...

  15. Combined shape and topology optimization of 3D structures

    DEFF Research Database (Denmark)

    Christiansen, Asger Nyman; Bærentzen, Jakob Andreas; Nobel-Jørgensen, Morten

    2015-01-01

    We present a method for automatic generation of 3D models based on shape and topology optimization. The optimization procedure, or model generation process, is initialized by a set of boundary conditions, an objective function, constraints and an initial structure. Using this input, the method...... will automatically deform and change the topology of the initial structure such that the objective function is optimized subject to the specified constraints and boundary conditions. For example, this tool can be used to improve the stiffness of a structure before printing, reduce the amount of material needed...

  16. Building blocks for topology change in 3D

    CERN Document Server

    Ionicioiu, R

    1997-01-01

    We investigate topology change in 3D. Using Morse theory and handle decomposition we find the set of elementary cobordisms for 3-manifolds. These are: (i) Ø S^2; (ii) \\Sigma_g \\Sigma_{g+1}; (iii) \\Sigma_{g_1} \\sqcup interpretations, e.g. Big Bang/Big Crunch, wormhole creation/annihilation and Einstein-Rosen bridge creation/annihilation, respectively. This decomposition into building blocks can be used in the path integral approach to quantum gravity in the sum over topologies.

  17. Topology optimization of 3D shell structures with porous infill

    Science.gov (United States)

    Clausen, Anders; Andreassen, Erik; Sigmund, Ole

    2017-08-01

    This paper presents a 3D topology optimization approach for designing shell structures with a porous or void interior. It is shown that the resulting structures are significantly more robust towards load perturbations than completely solid structures optimized under the same conditions. The study indicates that the potential benefit of using porous structures is higher for lower total volume fractions. Compared to earlier work dealing with 2D topology optimization, we found several new effects in 3D problems. Most notably, the opportunity for designing closed shells significantly improves the performance of porous structures due to the sandwich effect. Furthermore, the paper introduces improved filter boundary conditions to ensure a completely uniform coating thickness at the design domain boundary.

  18. Topology optimization of 3D Stokes flow problems

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Allan

    to different flow problems. However, this research has focused on 2D fluid modelling, which limits the practical impact of the computed designs. The explanation of the limitation is that the finite size domain used in topology optimization problems ensures that the velocity components couples, even for Stokes...... flow [3]. Furthermore, it is questionable if such a coupling can be captured by a 2D model especially in non-trivial geometries as typically seen in topology design. This statement is widely accepted in the fluid mechanics community, i.e. that planar fluid models are useful for academic test problems...... fundamental aspects of the topology optimization method applied to the Stokes equations as described below. This work consists of two parts. The main part elaborates on effects caused by 3D fluid modelling on the design. Numerical examples are shown where the design is planar - relevant to micro fluidic...

  19. 3D Genus Topology of Luminous Red Galaxies

    CERN Document Server

    Gott, J Richard; Park, Changbom; Kim, Juhan

    2008-01-01

    We measure the 3D genus topology of large scale structure using Luminous Red Galaxies (LRGs) in the Sloan Digital Sky Survey and find it consistent with the Gaussian random phase initial conditions expected from the simplest scenarios of inflation. This studies 3D topology on the largest scales ever obtained. The topology is sponge-like. We measure topology in two volume-limited samples: a dense shallow sample studied with smoothing length of 21h^{-1}Mpc, and a sparse deep sample studied with a smoothing length of 34h^{-1}Mpc. The amplitude of the genus curve is measured with 4% uncertainty. Small distortions in the genus curve expected from non-linear biasing and gravitational effects are well explained (to about 1-\\sigma accuracy) by N-body simulations using a subhalo-finding technique to locate LRGs. This suggests the formation of LRGs is a clean problem that can be modeled well without any free fitting parameters. This bodes well for using LRGs to measure the characteristic scales such as the baryon oscil...

  20. 3D surface topology guides stem cell adhesion and differentiation.

    Science.gov (United States)

    Viswanathan, Priyalakshmi; Ondeck, Matthew G; Chirasatitsin, Somyot; Ngamkham, Kamolchanok; Reilly, Gwendolen C; Engler, Adam J; Battaglia, Giuseppe

    2015-06-01

    Polymerized high internal phase emulsion (polyHIPE) foams are extremely versatile materials for investigating cell-substrate interactions in vitro. Foam morphologies can be controlled by polymerization conditions to result in either open or closed pore structures with different levels of connectivity, consequently enabling the comparison between 2D and 3D matrices using the same substrate with identical surface chemistry conditions. Additionally, here we achieve the control of pore surface topology (i.e. how different ligands are clustered together) using amphiphilic block copolymers as emulsion stabilizers. We demonstrate that adhesion of human mesenchymal progenitor (hES-MP) cells cultured on polyHIPE foams is dependent on foam surface topology and chemistry but is independent of porosity and interconnectivity. We also demonstrate that the interconnectivity, architecture and surface topology of the foams has an effect on the osteogenic differentiation potential of hES-MP cells. Together these data demonstrate that the adhesive heterogeneity of a 3D scaffold could regulate not only mesenchymal stem cell attachment but also cell behavior in the absence of soluble growth factors.

  1. 3D Topology optimization of Stokes flow problems

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Allan; Dammann, Bernd

    of energy efficient devices for 2D Stokes flow. Creeping flow problems are described by the Stokes equations which model very viscous fluids at macro scales or ordinary fluids at very small scales. The latter gives the motivation for topology optimization problems based on the Stokes equations being a model...... the designs are 3D. Moreover, preliminary results show that a formulation of an optimization problem that maximizes mixing with a constraint on the pressure drop across the device gives promising results. To measure the mixing a step temperature profile is convected through the design and the resulting...

  2. Topological Quantum Information in a 3D Neutral Atom Array

    Science.gov (United States)

    2015-01-02

    v Prescribed by ANSI Std. Z39.18 12-23-2014 Final 12-01-2008-9-30-2014 ( DARPA ) TOPOLOGICAL QUANTUM INFORMATION IN A 3D NEUTRAL ATOM ARRAY FA9550-09...1-0041 David Weiss Penn State UP76XR0 AFOSR DARPA Approved for public release Work was performed to build core elements of a quantum computer...Hamiltonian within our trapped neutral atoms architecture. quantum computing, ultracold atoms David Weiss 814-861-3578 1 DARPA Final Report Grant

  3. An overview of 3D topology for LADM-based objects

    NARCIS (Netherlands)

    Zulkifli, N.A.; Rahman, A.A.; Van Oosterom, P.J.M.

    2015-01-01

    This paper reviews 3D topology within Land Administration Domain Model (LADM) international standard. It is important to review characteristic of the different 3D topological models and to choose the most suitable model for certain applications. The characteristic of the different 3D topological mod

  4. Discretising geometry and preserving topology I

    CERN Document Server

    de Beauce, V; Beauce, Vivien de; Sen, Siddhartha

    2004-01-01

    A discretisation scheme that preserves topological features of a physical problem is extended so that differential geometric structures can be approximated while preserving topological features present. Issues of convergence and a numerical implementation are discussed. The follow-up article covers the resulting discretisation of Riemannian geometry and some applications.

  5. Spin-dependent Peltier effect in 3D topological insulators

    Science.gov (United States)

    Sengupta, Parijat; Kubis, Tillmann; Povolotskyi, Michael; Klimeck, Gerhard

    2013-03-01

    The Peltier effect represents the heat carrying capacity of a certain material when current passes through it. When two materials with different Peltier coefficients are placed together, the Peltier effect causes heat to flow either towards or away from the interface between them. This work utilizes the spin-polarized property of 3D topological insulator (TI) surface states to describe the transport of heat through the spin-up and spin-down channels. It has been observed that the spin channels are able to carry heat independently of each other. Spin currents can therefore be employed to supply or extract heat from an interface between materials with spin-dependent Peltier coefficients. The device is composed of a thin film of Bi2Se3 sandwiched between two layers of Bi2Te3. The thin film of Bi2Se3serves both as a normal and topological insulator. It is a normal insulator when its surfaces overlap to produce a finite band-gap. Using an external gate, Bi2Se3 film can be again tuned in to a TI. Sufficiently thick Bi2Te3 always retain TI behavior. Spin-dependent Peltier coefficients are obtained and the spin Nernst effect in TIs is shown by controlling the temperature gradient to convert charge current to spin current.

  6. Extension of RCC Topological Relations for 3d Complex Objects Components Extracted from 3d LIDAR Point Clouds

    Science.gov (United States)

    Xing, Xu-Feng; Abolfazl Mostafavia, Mir; Wang, Chen

    2016-06-01

    Topological relations are fundamental for qualitative description, querying and analysis of a 3D scene. Although topological relations for 2D objects have been extensively studied and implemented in GIS applications, their direct extension to 3D is very challenging and they cannot be directly applied to represent relations between components of complex 3D objects represented by 3D B-Rep models in R3. Herein we present an extended Region Connection Calculus (RCC) model to express and formalize topological relations between planar regions for creating 3D model represented by Boundary Representation model in R3. We proposed a new dimension extended 9-Intersection model to represent the basic relations among components of a complex object, including disjoint, meet and intersect. The last element in 3*3 matrix records the details of connection through the common parts of two regions and the intersecting line of two planes. Additionally, this model can deal with the case of planar regions with holes. Finally, the geometric information is transformed into a list of strings consisting of topological relations between two planar regions and detailed connection information. The experiments show that the proposed approach helps to identify topological relations of planar segments of point cloud automatically.

  7. Topology optimization of 3D Stokes flow problems

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Allan

    to different flow problems. However, this research has focused on 2D fluid modelling, which limits the practical impact of the computed designs. The explanation of the limitation is that the finite size domain used in topology optimization problems ensures that the velocity components couples, even for Stokes......Topology optimization has been applied to a multitude of physical systems and is now a mature technology used in industrial practice, see [1] for an overview. Borrvall and Petersson [2] introduced topology optimization of Stokes flow problems which initiated works on extending topology optimization...... flow [3]. Furthermore, it is questionable if such a coupling can be captured by a 2D model especially in non-trivial geometries as typically seen in topology design. This statement is widely accepted in the fluid mechanics community, i.e. that planar fluid models are useful for academic test problems...

  8. 3D interactive topology optimization on hand-held devices

    DEFF Research Database (Denmark)

    Nobel-Jørgensen, Morten; Aage, Niels; Christiansen, Asger Nyman;

    2015-01-01

    This educational paper describes the implementation aspects, user interface design considerations and workflow potential of the recently published TopOpt 3D App. The app solves the standard minimum compliance problem in 3D and allows the user to change design settings interactively at any point i...

  9. Topology optimization of 3D Stokes flow problems

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Allan; Sigmund, Ole; Bendsøe, Martin P.

    is caused by the finite size domain used in topology optimization problems which ensures that the velocity components couples, even for Stokes flow [3]. Physically Stokes flow is an exotic inertia free flow, which in practice complicates mixing by passive devices. Passive mixing devices are relevant......The design of MEMS devices have benefitted from the topology optimization tool and complicated layout problems have been solved, see [1] for an overview. This research is aimed at micro fluidic devices known as micro-Total-Analysis-Systems (muTAS) where the main physical phenomena originate from...... fluid mechanics. In future practice a muTAS could be used by doctors, engineers etc. as a hand held device with short reaction time that provides on-site analysis of a flowing substance such as blood, polluted water or similar. Borrvall and Petersson [2] paved the road for using the topology...

  10. A topological framework for interactive queries on 3D models in the Web.

    Science.gov (United States)

    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.

  11. Electrified magnetic catalysis in 3D topological insulators

    CERN Document Server

    Gorbar, E V; Shovkovy, I A; Sukhachov, P O

    2016-01-01

    The gap equations for the surface quasiparticle propagators in a slab of three-dimensional topological insulator in external electric and magnetic fields perpendicular to the slab surfaces are analyzed and solved. A new type of magnetic catalysis is revealed with the dynamical generation of both Haldane and Dirac gaps. Its characteristic feature manifests itself in the crucial role that the electric field plays in dynamical symmetry breaking and the generation of a Dirac gap in the slab. It is argued that, for a sufficiently large external electric field, the ground state of the system is a phase with a homogeneous surface charge density.

  12. Samarium Hexaboride: The First True 3D Topological Insulator?

    Science.gov (United States)

    Wolgast, Steven G.

    The recent theoretical prediction of a topologically protected surface state in the mixed-valent insulator SmB6 has motivated a series of charge transport studies, which are presented here. It is first studied using a specialized configuration designed to distinguish bulk-dominated conduction from surface-dominated conduction. As the material is cooled below 4 K, it exhibits a crossover from thermally activated bulk transport to metallic surface conduction with a fully insulating bulk. The robustness and magnitude of the surface conductivity, as is manifest in the literature of SmB6, is strong evidence for the topological insulator (TI) metallic surface states predicted for this material. This resolves a decades-old puzzle surrounding the low-temperature behavior of SmB6. Next, the magnetotransport properties of the surface are investigated using a Corbino disk geometry, which can directly measure the conductivity of individual surfaces. Both (011) and (001) crystal surfaces show a strong negative magnetoresistance at all magnetic field angles, due primarily to changes in the carrier density. The low mobility value accounts for the failure so far to observe Shubnikov-de Haas oscillations below 95 T. Small variations in the mobility and temperature dependence suggest a suppression of Kondo scattering from native oxide-layer magnetic moments. At low fields, a dynamical field-sweep-rate-dependent hysteretic behavior is observed. It persists at the slowest sweep rates, and cannot be explained by quantum interference corrections; it is likely due to extrinsic effects such as the magnetocaloric effect or glassy ordering of the native oxide moments. Pulsed magnetic field measurements up to 60 T at temperatures throughout the crossover regime clearly distinguish the surface magnetoresistance from the bulk magnetoresistance. The bulk magnetoresistance is due to a reduction in the bulk gap with increasing magnetic field. Finally, small subsurface cracks formed in SmB6 via

  13. Backbone cup – a structure design competition based on topology optimization and 3D printing

    Directory of Open Access Journals (Sweden)

    Zhu Ji-Hong

    2016-01-01

    Full Text Available This paper addresses a structure design competition based on topology optimization and 3D Printing, and proposes an experimental approach to efficiently and quickly measure the mechanical performance of the structures designed using topology optimization. Since the topology optimized structure designs are prone to be geometrically complex, it is extremely inconvenient to fabricate these designs with traditional machining. In this study, we not only fabricated the topology optimized structure designs using one kind of 3D Printing technology known as stereolithography (SLA, but also tested the mechanical performance of the produced prototype parts. The finite element method is used to analyze the structure responses, and the consistent results of the numerical simulations and structure experiments prove the validity of this new structure testing approach. This new approach will not only provide a rapid access to topology optimized structure designs verifying, but also cut the turnaround time of structure design significantly.

  14. Surface-preserving robust watermarking of 3-D shapes.

    Science.gov (United States)

    Luo, Ming; Bors, Adrian G

    2011-10-01

    This paper describes a new statistical approach for watermarking mesh representations of 3-D graphical objects. A robust digital watermarking method has to mitigate among the requirements of watermark invisibility, robustness, embedding capacity and key security. The proposed method employs a mesh propagation distance metric procedure called the fast marching method (FMM), which defines regions of equal geodesic distance width calculated with respect to a reference location on the mesh. Each of these regions is used for embedding a single bit. The embedding is performed by changing the normalized distribution of local geodesic distances from within each region. Two different embedding methods are used by changing the mean or the variance of geodesic distance distributions. Geodesic distances are slightly modified statistically by displacing the vertices in their existing triangle planes. The vertex displacements, performed according to the FMM, ensure a minimal surface distortion while embedding the watermark code. Robustness to a variety of attacks is shown according to experimental results.

  15. Topology Optimization Design of 3D Continuum Structure with Reserved Hole Based on Variable Density Method

    Directory of Open Access Journals (Sweden)

    Bai Shiye

    2016-05-01

    Full Text Available An objective function defined by minimum compliance of topology optimization for 3D continuum structure was established to search optimal material distribution constrained by the predetermined volume restriction. Based on the improved SIMP (solid isotropic microstructures with penalization model and the new sensitivity filtering technique, basic iteration equations of 3D finite element analysis were deduced and solved by optimization criterion method. All the above procedures were written in MATLAB programming language, and the topology optimization design examples of 3D continuum structure with reserved hole were examined repeatedly by observing various indexes, including compliance, maximum displacement, and density index. The influence of mesh, penalty factors, and filter radius on the topology results was analyzed. Computational results showed that the finer or coarser the mesh number was, the larger the compliance, maximum displacement, and density index would be. When the filtering radius was larger than 1.0, the topology shape no longer appeared as a chessboard problem, thus suggesting that the presented sensitivity filtering method was valid. The penalty factor should be an integer because iteration steps increased greatly when it is a noninteger. The above modified variable density method could provide technical routes for topology optimization design of more complex 3D continuum structures in the future.

  16. Synthesis, structure and properties of a 3D acentric coordination polymer with noninterpenetrated (10,3)-d topology

    Science.gov (United States)

    Lun, Huijie; Li, Xuefei; Wang, Xiao; Li, Haiyan; Li, Yamin; Bai, Yan

    2017-01-01

    A new coordination polymer, {[Mn(HPIDC)(H2O)]·2H2O}n (1) (H3PIDC = 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid), has been obtained by hydrothermal method and structurally characterized by X-ray single crystal diffraction, elemental analysis and thermogravimetric analysis (TGA). X-ray single crystal diffraction reveals that compound 1 crystallizing in acentric Pna21 space group, exhibits an ultimate racemic three-dimension framework with rare noninterpenetrated (10,3)-d (or utp) topology due to the alternate array of left- and right-handed helixes. Moreover, compound 1 also features ferroelectric, nonlinear optical (NLO) and antiferromagnetic behaviors.

  17. An efficient topology adaptation system for parametric active contour segmentation of 3D images

    Science.gov (United States)

    Abhau, Jochen; Scherzer, Otmar

    2008-03-01

    Active contour models have already been used succesfully for segmentation of organs from medical images in 3D. In implicit models, the contour is given as the isosurface of a scalar function, and therefore topology adaptations are handled naturally during a contour evolution. Nevertheless, explicit or parametric models are often preferred since user interaction and special geometric constraints are usually easier to incorporate. Although many researchers have studied topology adaptation algorithms in explicit mesh evolutions, no stable algorithm is known for interactive applications. In this paper, we present a topology adaptation system, which consists of two novel ingredients: A spatial hashing technique is used to detect self-colliding triangles of the mesh whose expected running time is linear with respect to the number of mesh vertices. For the topology change procedure, we have developed formulas by homology theory. During a contour evolution, we just have to choose between a few possible mesh retriangulations by local triangle-triangle intersection tests. Our algorithm has several advantages compared to existing ones: Since the new algorithm does not require any global mesh reparametrizations, it is very efficient. Since the topology adaptation system does not require constant sampling density of the mesh vertices nor especially smooth meshes, mesh evolution steps can be performed in a stable way with a rather coarse mesh. We apply our algorithm to 3D ultrasonic data, showing that accurate segmentation is obtained in some seconds.

  18. $(1+3)$D topological superconductors: screening and confinement in presence of external fields

    CERN Document Server

    Gaete, Patricio

    2016-01-01

    Adopting the gauge-invariant and path-dependent variables formalism, we compute the interaction energy for a topological field theory describing $(1+3)$D topological superconductors in presence of external fields. As a result, in the case of a constant electric field- strength expectation value, we show that the interaction energy describes a purely screening phase, encoded in a Yukawa potential. On the other hand, in the case of a constant magnetic field-strength and for a very small Josephson coupling constant, the particle-antiparticle binding potential displays a linear term leading to the confinement of static charge probes along with a screening contribution.

  19. Rhorix: An interface between quantum chemical topology and the 3D graphics program blender.

    Science.gov (United States)

    Mills, Matthew J L; Sale, Kenneth L; Simmons, Blake A; Popelier, Paul L A

    2017-08-31

    Chemical research is assisted by the creation of visual representations that map concepts (such as atoms and bonds) to 3D objects. These concepts are rooted in chemical theory that predates routine solution of the Schrödinger equation for systems of interesting size. The method of Quantum Chemical Topology (QCT) provides an alternative, parameter-free means to understand chemical phenomena directly from quantum mechanical principles. Representation of the topological elements of QCT has lagged behind the best tools available. Here, we describe a general abstraction (and corresponding file format) that permits the definition of mappings between topological objects and their 3D representations. Possible mappings are discussed and a canonical example is suggested, which has been implemented as a Python "Add-On" named Rhorix for the state-of-the-art 3D modeling program Blender. This allows chemists to use modern drawing tools and artists to access QCT data in a familiar context. A number of examples are discussed. © 2017 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. © 2017 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.

  20. Quantum anomalous Hall effect and tunable topological states in 3d transition metals doped silicene.

    Science.gov (United States)

    Zhang, Xiao-Long; Liu, Lan-Feng; Liu, Wu-Ming

    2013-10-09

    Silicene is an intriguing 2D topological material which is closely analogous to graphene but with stronger spin orbit coupling effect and natural compatibility with current silicon-based electronics industry. Here we demonstrate that silicene decorated with certain 3d transition metals (Vanadium) can sustain a stable quantum anomalous Hall effect using both analytical model and first-principles Wannier interpolation. We also predict the quantum valley Hall effect and electrically tunable topological states could be realized in certain transition metal doped silicene where the energy band inversion occurs. Our findings provide new scheme for the realization of quantum anomalous Hall effect and platform for electrically controllable topological states which are highly desirable for future nanoelectronics and spintronics application.

  1. Topology optimized and 3D printed polymer-bonded permanent magnets for a predefined external field

    Science.gov (United States)

    Huber, C.; Abert, C.; Bruckner, F.; Pfaff, C.; Kriwet, J.; Groenefeld, M.; Teliban, I.; Vogler, C.; Suess, D.

    2017-08-01

    Topology optimization offers great opportunities to design permanent magnetic systems that have specific external field characteristics. Additive manufacturing of polymer-bonded magnets with an end-user 3D printer can be used to manufacture permanent magnets with structures that had been difficult or impossible to manufacture previously. This work combines these two powerful methods to design and manufacture permanent magnetic systems with specific properties. The topology optimization framework is simple, fast, and accurate. It can also be used for the reverse engineering of permanent magnets in order to find the topology from field measurements. Furthermore, a magnetic system that generates a linear external field above the magnet is presented. With a volume constraint, the amount of magnetic material can be minimized without losing performance. Simulations and measurements of the printed systems show very good agreement.

  2. Quantized Faraday and Kerr rotation and axion electrodynamics of a 3D topological insulator

    Science.gov (United States)

    Wu, Liang; Salehi, M.; Koirala, N.; Moon, J.; Oh, S.; Armitage, N. P.

    2016-12-01

    Topological insulators have been proposed to be best characterized as bulk magnetoelectric materials that show response functions quantized in terms of fundamental physical constants. Here, we lower the chemical potential of three-dimensional (3D) Bi2Se3 films to ~30 meV above the Dirac point and probe their low-energy electrodynamic response in the presence of magnetic fields with high-precision time-domain terahertz polarimetry. For fields higher than 5 tesla, we observed quantized Faraday and Kerr rotations, whereas the dc transport is still semiclassical. A nontrivial Berry’s phase offset to these values gives evidence for axion electrodynamics and the topological magnetoelectric effect. The time structure used in these measurements allows a direct measure of the fine-structure constant based on a topological invariant of a solid-state system.

  3. CC-Modeler: a topology generator for 3-D city models

    Science.gov (United States)

    Gruen, Armin; Wang, Xinhua

    In this paper, we introduce a semi-automated topology generator for 3-D objects, CC-Modeler (CyberCity Modeler). Given the data as point clouds measured on Analytical Plotters or Digital Stations, we present a new method for fitting planar structures to the measured sets of point clouds. While this topology generator has been originally designed to model buildings, it can also be used for other objects, which may be approximated by polyhedron surfaces. We have used it so far for roads, rivers, parking lots, ships, etc. The CC-Modeler is a generic topology generator. The problem of fitting planar faces to point clouds is treated as a Consistent Labelling problem, which is solved by probabilistic relaxation. Once the faces are defined and the related points are determined, we apply a simultaneous least-squares adjustment in order to fit the faces jointly to the given measurements in an optimal way. We first present the processing flow of the CC-Modeler. Then, the algorithm of structuring the 3-D point data is outlined. Finally, we show the results of several data sets that have been produced with the CC-Modeler.

  4. MBE - growth of capped, strained HgTe, a 3D topological insulator

    Energy Technology Data Exchange (ETDEWEB)

    Ames, Christopher; Leubner, Philipp; Bruene, Christoph; Buhmann, Hartmut; Molenkamp, Laurens [Universitaet Wuerzburg, D-97074 Wuerzburg (Germany)

    2013-07-01

    The discovery of two (2D) and three dimensional (3D) topological insulator (TI) behavior in HgTe - systems opens a large field for studying magneto transport properties of both. We grow HgTe as a 3D topological insulator by molecular beam epitaxy. Unstrained bulk HgTe is a semimetal but opens a gap of roughly 22 meV when grown fully strained on <001> CdTe substrate due to 0.3 % lattice mismatch and shows magnetotransport properties of a 3D TI. Hall measurements show electron mobilities of around 50.000 cm{sup 2}(V s){sup -1}. To increase electron mobilities, various growth optimizations have been carried out. Firstly we grew an HgCdTe buffer layer between the substrate and bulk HgTe. Different buffer thicknesses were analyzed ex-situ by HRXRD, AFM and standard Hall measurements. Secondly, we added a cap-layer of HgCdTe on top of the bulk HgTe. Doing so, we were able to raise the electron mobility of the bulk HgTe up to one order of magnitude. Time-dependent XPS measurements allowed us to hold the suppressed oxidization of the surface responsible for this effect. Through the advanced material quality we have now more prospects for better understanding of the transport properties in strained HgTe.

  5. Compression of 2D vector fields under guaranteed topology preservation

    OpenAIRE

    2003-01-01

    In this paper we introduce a new compression technique for 2D vector fields which preserves the complete topology, i.e., the critical points and the connectivity of the separatrices. As the theoretical foundation of the algorithm, we show in a theorem that for local modifications of a vector field, it is possible to decide entirely by a local analysis whether or not the global topology is preserved. This result is applied in a compression algorithm which is based on a ...

  6. 3D TOPOLOGICAL INDOOR BUILDING MODELING INTEGRATED WITH OPEN STREET MAP

    Directory of Open Access Journals (Sweden)

    A. Jamali

    2016-09-01

    Full Text Available Considering various fields of applications for building surveying and various demands, geometry representation of a building is the most crucial aspect of a building survey. The interiors of the buildings need to be described along with the relative locations of the rooms, corridors, doors and exits in many kinds of emergency response, such as fire, bombs, smoke, and pollution. Topological representation is a challenging task within the Geography Information Science (GIS environment, as the data structures required to express these relationships are particularly difficult to develop. Even within the Computer Aided Design (CAD community, the structures for expressing the relationships between adjacent building parts are complex and often incomplete. In this paper, an integration of 3D topological indoor building modeling in Dual Half Edge (DHE data structure and outdoor navigation network from Open Street Map (OSM is presented.

  7. How to Extract the Geometry and Topology from Very Large 3D Segmentations

    CERN Document Server

    Andres, Bjoern; Kroeger, Thorben; Hamprecht, Fred A

    2010-01-01

    Segmentation is often an essential intermediate step in image analysis. A volume segmentation characterizes the underlying volume image in terms of geometric information--segments, faces between segments, curves in which several faces meet--as well as a topology on these objects. Existing algorithms encode this information in designated data structures, but require that these data structures fit entirely in Random Access Memory (RAM). Today, 3D images with several billion voxels are acquired, e.g. in structural neurobiology. Since these large volumes can no longer be processed with existing methods, we present a new algorithm which performs geometry and topology extraction with a runtime linear in the number of voxels and log-linear in the number of faces and curves. The parallelizable algorithm proceeds in a block-wise fashion and constructs a consistent representation of the entire volume image on the hard drive, making the structure of very large volume segmentations accessible to image analysis. The paral...

  8. Biological insights from topology independent comparison of protein 3D structures.

    Science.gov (United States)

    Nguyen, Minh N; Madhusudhan, M S

    2011-08-01

    Comparing and classifying the three-dimensional (3D) structures of proteins is of crucial importance to molecular biology, from helping to determine the function of a protein to determining its evolutionary relationships. Traditionally, 3D structures are classified into groups of families that closely resemble the grouping according to their primary sequence. However, significant structural similarities exist at multiple levels between proteins that belong to these different structural families. In this study, we propose a new algorithm, CLICK, to capture such similarities. The method optimally superimposes a pair of protein structures independent of topology. Amino acid residues are represented by the Cartesian coordinates of a representative point (usually the C(α) atom), side chain solvent accessibility, and secondary structure. Structural comparison is effected by matching cliques of points. CLICK was extensively benchmarked for alignment accuracy on four different sets: (i) 9537 pair-wise alignments between two structures with the same topology; (ii) 64 alignments from set (i) that were considered to constitute difficult alignment cases; (iii) 199 pair-wise alignments between proteins with similar structure but different topology; and (iv) 1275 pair-wise alignments of RNA structures. The accuracy of CLICK alignments was measured by the average structure overlap score and compared with other alignment methods, including HOMSTRAD, MUSTANG, Geometric Hashing, SALIGN, DALI, GANGSTA(+), FATCAT, ARTS and SARA. On average, CLICK produces pair-wise alignments that are either comparable or statistically significantly more accurate than all of these other methods. We have used CLICK to uncover relationships between (previously) unrelated proteins. These new biological insights include: (i) detecting hinge regions in proteins where domain or sub-domains show flexibility; (ii) discovering similar small molecule binding sites from proteins of different folds and (iii

  9. Surface states in a 3D topological insulator: The role of hexagonal warping and curvature

    Energy Technology Data Exchange (ETDEWEB)

    Repin, E. V.; Burmistrov, I. S., E-mail: burmi@itp.ac.ru [Moscow Institute of Physics and Technology (Russian Federation)

    2015-09-15

    We explore a combined effect of hexagonal warping and a finite effective mass on both the tunneling density of electronic surface states and the structure of Landau levels of 3D topological insulators. We find the increasing warping to transform the square-root van Hove singularity into a logarithmic one. For moderate warping, an additional logarithmic singularity and a jump in the tunneling density of surface states appear. By combining the perturbation theory and the WKB approximation, we calculate the Landau levels in the presence of hexagonal warping. We predict that due to the degeneracy removal, the evolution of Landau levels in the magnetic field is drastically modified.

  10. 3D Dynamics of 4D Topological BF Theory With Boundary

    CERN Document Server

    Amoretti, Andrea; Maggiore, Nicola; Magnoli, Nicodemo

    2012-01-01

    We consider the four dimensional abelian topological BF theory with a planar boundary introduced following the Symanzik's method. We find the most general boundary conditions compatible with the fields equations broken by the boundary. The residual gauge invariance is described by means of two Ward identities which generate an algebra of conserved currents. We interpret this algebra as canonical commutation relations of fields, which we use to construct a three dimensional Lagrangian. As a remarkable by-product, the (unique) boundary condition which we found, can be read as a duality relation between 3D dynamical variables.

  11. Strong interband Faraday rotation in 3D topological insulator Bi2Se3.

    Science.gov (United States)

    Ohnoutek, L; Hakl, M; Veis, M; Piot, B A; Faugeras, C; Martinez, G; Yakushev, M V; Martin, R W; Drašar, Č; Materna, A; Strzelecka, G; Hruban, A; Potemski, M; Orlita, M

    2016-01-11

    The Faraday effect is a representative magneto-optical phenomenon, resulting from the transfer of angular momentum between interacting light and matter in which time-reversal symmetry has been broken by an externally applied magnetic field. Here we report on the Faraday rotation induced in the prominent 3D topological insulator Bi2Se3 due to bulk interband excitations. The origin of this non-resonant effect, extraordinarily strong among other non-magnetic materials, is traced back to the specific Dirac-type Hamiltonian for Bi2Se3, which implies that electrons and holes in this material closely resemble relativistic particles with a non-zero rest mass.

  12. Giant Faraday effect due to Pauli exclusion principle in 3D topological insulators.

    Science.gov (United States)

    Paudel, Hari P; Leuenberger, Michael N

    2014-02-26

    Experiments using ARPES, which is based on the photoelectric effect, show that the surface states in 3D topological insulators (TI) are helical. Here we consider Weyl interface fermions due to band inversion in narrow-bandgap semiconductors, such as Pb1-xSnxTe. The positive and negative energy solutions can be identified by means of opposite helicity in terms of the spin helicity operator in 3D TI as ĥ(TI) = (1/ |p|_ |) β (σ|_ x p|_ ) · z^, where β is a Dirac matrix and z^ points perpendicular to the interface. Using the 3D Dirac equation and bandstructure calculations we show that the transitions between positive and negative energy solutions, giving rise to electron-hole pairs, obey strict optical selection rules. In order to demonstrate the consequences of these selection rules, we consider the Faraday effect due to the Pauli exclusion principle in a pump-probe setup using a 3D TI double interface of a PbTe/Pb₀.₃₁Sn₀.₆₉Te/PbTe heterostructure. For that we calculate the optical conductivity tensor of this heterostructure, which we use to solve Maxwell's equations. The Faraday rotation angle exhibits oscillations as a function of probe wavelength and thickness of the heterostructure. The maxima in the Faraday rotation angle are of the order of mrds.

  13. Simulating 3D $Z_2$ Topological Nodes in Nonsymmorphic Photonic Crystals

    CERN Document Server

    Wang, Hai-Xiao; Hang, Zhi Hong; Chen, Huanyang; Kee, Hae-Young; Jiang, Jian-Hua

    2016-01-01

    We propose an all-dielectric, space-time reversal symmetric photonics-crystal architecture that possess 3D Dirac points and line-nodes with nontrivial $Z_2$ topological charge, which can be realized at infrared and microwave frequencies. The protected degeneracy of bands is achieved via nonsymmorphic symmetries despite the lack of Kramers degeneracy in photonic crystal systems. Two orthogonal screw axes lead to 3D $Z_2$ Dirac points on high symmetry Brillouin zone (BZ) boundary line. On the other hand, twofold $Z_2$ line-nodes appear around the $\\Gamma$-point due to a combination of nonsymmorphic and point-group symmetries. The lowest line-node is deterministic because of degeneracy partner switching between Bloch states with opposite parities. A pair of Fermi arcs associated with $Z_2$ topological charge is emerged below light-line and protected by total internal reflection on certain photonic-crystal-air interfaces. These robust surface states offer an unique opportunity to realize "open cavity" with strong...

  14. Interfacing 2D and 3D Topological Insulators: Bi(111) Bilayer on Bi2Te3

    Science.gov (United States)

    Hirahara, Toru; Bihlmayer, Gustav; Sakamoto, Yusuke; Yamada, Manabu; Miyazaki, Hidetoshi; Kimura, Shin-Ichi; Blügel, Stefan; Hasegawa, Shuji

    2012-02-01

    Topological insulators (TI) are insulating materials but have metallic edge states that carry spin currents and are robust against nonmagnetic impurities [1]. While there have been a large number of reports on three-dimensional (3D) TI, only few works have been done in terms of two-dimensional (2D) TI. In the present paper, we report the successful formation of bilayer Bi, which was theoretically predicted to be a 2D TI [2]. We deposited bilayer Bi on a 3D TI Bi2Te3, which the lattice mismatch is very small. From angle-resolved photoemission spectroscopy measurements and ab initio calculations, the electronic structure of the system can be understood as an overlap of the band dispersions of bilayer Bi and Bi2Te3. Our results show that the Dirac cone is actually robust against nonmagnetic perturbations and imply a unique situation where the topologically protected one- and two-dimensional edge states are coexisting at the surface [3]. [0pt] [1] M. Z. Hasan and C. L. Kane, Rev. Mod. Phys. 82, 3045 (2010).[0pt] [2] S. Murakami, Phys. Rev. Lett. 97, 236805 (2006).[0pt] [3] T. Hirahara et al., Phys. Rev. Lett. 107, 166801 (2011).

  15. Designing patient-specific 3D printed craniofacial implants using a novel topology optimization method.

    Science.gov (United States)

    Sutradhar, Alok; Park, Jaejong; Carrau, Diana; Nguyen, Tam H; Miller, Michael J; Paulino, Glaucio H

    2016-07-01

    Large craniofacial defects require efficient bone replacements which should not only provide good aesthetics but also possess stable structural function. The proposed work uses a novel multiresolution topology optimization method to achieve the task. Using a compliance minimization objective, patient-specific bone replacement shapes can be designed for different clinical cases that ensure revival of efficient load transfer mechanisms in the mid-face. In this work, four clinical cases are introduced and their respective patient-specific designs are obtained using the proposed method. The optimized designs are then virtually inserted into the defect to visually inspect the viability of the design . Further, once the design is verified by the reconstructive surgeon, prototypes are fabricated using a 3D printer for validation. The robustness of the designs are mechanically tested by subjecting them to a physiological loading condition which mimics the masticatory activity. The full-field strain result through 3D image correlation and the finite element analysis implies that the solution can survive the maximum mastication of 120 lb. Also, the designs have the potential to restore the buttress system and provide the structural integrity. Using the topology optimization framework in designing the bone replacement shapes would deliver surgeons new alternatives for rather complicated mid-face reconstruction.

  16. Hierarchical 3D mechanical parts matching based-on adjustable geometry and topology similarity measurements

    Institute of Scientific and Technical Information of China (English)

    马嵩华; 田凌

    2014-01-01

    A hierarchical scheme of feature-based model similarity measurement was proposed, named CSG_D2, in which both geometry similarity and topology similarity were applied. The features of 3D mechanical part were constructed by a series of primitive features with tree structure, as a form of constructive solid geometry (CSG) tree. The D2 shape distributions of these features were extracted for geometry similarity measurement, and the pose vector and non-disappeared proportion of each leaf node were gained for topology similarity measurement. Based on these, the dissimilarity between the query and the candidate was accessed by level-by-level CSG tree comparisons. With the adjustable weights, our scheme satisfies different comparison emphasis on the geometry or topology similarity. The assessment results from CSG_D2 demonstrate more discriminative than those from D2 in the analysis of precision-recall and similarity matrix. Finally, an experimental search engine is applied for mechanical parts reuse by using CSG_D2, which is convenient for the mechanical design process.

  17. An approach to develop 3d Geo-DBMS topological operators by re-using existing 2d operators

    NARCIS (Netherlands)

    Xu, D.; Zlatanova, S.

    2013-01-01

    Database systems are continuously extending their capabilities to store, process and analyse 3D data. Topological relationships which describe the interaction of objects in space is one of the important spatial issues. However, spatial operators for 3D objects are still insufficient. In this paper w

  18. Reasoning about geological space: Coupling 3D GeoModels and topological queries as an aid to spatial data selection

    Science.gov (United States)

    Pouliot, Jacynthe; Bédard, Karine; Kirkwood, Donna; Lachance, Bernard

    2008-05-01

    Topological relationships between geological objects are of great interest for mining and petroleum exploration. Indeed, adjacency, inclusion and intersection are common relationships between geological objects such as faults, geological units, fractures, mineralized zones and reservoirs. However, in the context of 3D modeling, actual geometric data models used to store those objects are not designed to manage explicit topological relationships. For example, with Gocad© software, topological analyses are possible but they require a series of successive manipulations and are time consuming. This paper presents the development of a 3D topological query prototype, TQuery, compatible with Gocad© modeling platform. It allows the user to export Gocad© objects to a data storage model that regularizes the topological relationships between objects. The development of TQuery was oriented towards the use of volumetric objects that are composed of tetrahedrons. Exported data are then retrieved and used for 3D topological and spatial queries. One of the advantages of TQuery is that different types of objects can be queried at the same time without restricting the operations to voxel regions. TQuery allows the user to analyze data more quickly and efficiently and does not require a 3D modeling specialist to use it, which is particularly attractive in the context of a decision-making aid. The prototype was tested on a 3D GeoModel of a continental red-bed copper deposit in the Silurian Robitaille Formation (Transfiguration property, Québec, Canada).

  19. Enzymes/non-enzymes classification model complexity based on composition, sequence, 3D and topological indices.

    Science.gov (United States)

    Munteanu, Cristian Robert; González-Díaz, Humberto; Magalhães, Alexandre L

    2008-09-21

    The huge amount of new proteins that need a fast enzymatic activity characterization creates demands of protein QSAR theoretical models. The protein parameters that can be used for an enzyme/non-enzyme classification includes the simpler indices such as composition, sequence and connectivity, also called topological indices (TIs) and the computationally expensive 3D descriptors. A comparison of the 3D versus lower dimension indices has not been reported with respect to the power of discrimination of proteins according to enzyme action. A set of 966 proteins (enzymes and non-enzymes) whose structural characteristics are provided by PDB/DSSP files was analyzed with Python/Biopython scripts, STATISTICA and Weka. The list of indices includes, but it is not restricted to pure composition indices (residue fractions), DSSP secondary structure protein composition and 3D indices (surface and access). We also used mixed indices such as composition-sequence indices (Chou's pseudo-amino acid compositions or coupling numbers), 3D-composition (surface fractions) and DSSP secondary structure amino acid composition/propensities (obtained with our Prot-2S Web tool). In addition, we extend and test for the first time several classic TIs for the Randic's protein sequence Star graphs using our Sequence to Star Graph (S2SG) Python application. All the indices were processed with general discriminant analysis models (GDA), neural networks (NN) and machine learning (ML) methods and the results are presented versus complexity, average of Shannon's information entropy (Sh) and data/method type. This study compares for the first time all these classes of indices to assess the ratios between model accuracy and indices/model complexity in enzyme/non-enzyme discrimination. The use of different methods and complexity of data shows that one cannot establish a direct relation between the complexity and the accuracy of the model.

  20. Contribution of Topological Domains and Loop Formation to 3D Chromatin Organization

    Directory of Open Access Journals (Sweden)

    Vuthy Ea

    2015-07-01

    Full Text Available Recent investigations on 3D chromatin folding revealed that the eukaryote genomes are both highly compartmentalized and extremely dynamic. This review presents the most recent advances in topological domains’ organization of the eukaryote genomes and discusses the relationship to chromatin loop formation. CTCF protein appears as a central factor of these two organization levels having either a strong insulating role at TAD borders, or a weaker architectural role in chromatin loop formation. TAD borders directly impact on chromatin dynamics by restricting contacts within specific genomic portions thus confining chromatin loop formation within TADs. We discuss how sub-TAD chromatin dynamics, constrained into a recently described statistical helix conformation, can produce functional interactions by contact stabilization.

  1. Enhanced Mobility of Spin-Helical Dirac Fermions in Disordered 3D Topological Insulators

    Science.gov (United States)

    Dufouleur, Joseph; Veyrat, Louis; Dassonneville, Bastien; Nowka, Christian; Hampel, Silke; Leksin, Pavel; Eichler, Barbara; Schmidt, Oliver G.; Büchner, Bernd; Giraud, Romain

    2016-11-01

    The transport length $l_\\textrm{tr}$ and the mean free path $l_\\textrm{e}$ are experimentally determined for bulk and surface states in a Bi$_2$Se$_3$ nanoribbon by quantum transport and transconductance measurements. We show that the anisotropic scattering of spin-helical Dirac fermions results in a strong enhancement of $l_\\textrm{tr}$, which confirms theoretical predictions \\cite{Culcer2010}. Despite strong disorder ($l_\\textrm{e}\\approx30$~nm), our result further points to the long-range nature of the scattering potential, giving a large ratio $l_\\textrm{tr}/l_\\textrm{e}\\approx8$ that is likely limited by a finite bulk/surface coupling. This suggests that the spin-flip length could reach the micron size in disordered 3D topological insulator nanostructures with a reduced bulk doping, even if due to charge compensation.

  2. Topology-Preserving Rigid Transformation of 2D Digital Images.

    Science.gov (United States)

    Ngo, Phuc; Passat, Nicolas; Kenmochi, Yukiko; Talbot, Hugues

    2014-02-01

    We provide conditions under which 2D digital images preserve their topological properties under rigid transformations. We consider the two most common digital topology models, namely dual adjacency and well-composedness. This paper leads to the proposal of optimal preprocessing strategies that ensure the topological invariance of images under arbitrary rigid transformations. These results and methods are proved to be valid for various kinds of images (binary, gray-level, label), thus providing generic and efficient tools, which can be used in particular in the context of image registration and warping.

  3. Ferromagnetic interactions between transition-metal impurities in topological and 3D Dirac semimetals

    Science.gov (United States)

    Dietl, Tomasz

    The magnitude of ferromagnetic coupling driven by inter-band (Bloembergen-Rowland - BR) and intra-band (Ruderman-Kittel-Kasuya-Yoshida - RKKY) spin polarization is evaluated within kp theory for topological semimetals Hg1-xMnxTe and Hg1-xMnxSe as well as for 3D Dirac semimetal (Cd1-xMnx)3As2. In these systems Mn2+ ions do not introduce any carriers. Since, however, both conduction and valence bands are built from anion p-type wave functions, hybridization of Mn d levels with neighboring anion p states leads to spin-dependent p - d coupling of both electrons and holes to localized Mn spins, resulting in sizable inter-band spin polarization and, thus in large BR interactions. We demonstrate that this ferromagnetic coupling, together with antiferromagnetic superexchange, elucidate a specific dependence of spin-glass freezing temperature on x, determined experimentally for these systems. Furthermore, by employing a multi-orbital tight-binding method, we find that superexchange becomes ferromagnetic when Mn is replaced by Cr or V. Since Cr should act as an isoelectronic impurity in HgTe, this opens a road for realization of ferromagnetic topological insulators based on (Hg,Cr)Te.

  4. Facilitating Identification of Poorly Preserved Marine Microfossils through 3D Printing

    Science.gov (United States)

    Christensen, R. V.; Robinson, M. M.; Sessa, J.

    2016-12-01

    The Paleocene-Eocene Thermal Maximum (PETM) was a period of sudden and intense global warming that occurred 56 Myr, and is widely considered a possible analogue for future climatic changes. Marine microfossils are important proxies used in the reconstruction of PETM paleoenvironments and paleoclimate. The correct species-level identification of foraminifera and pteropod specimens is necessary to understand ocean temperature, chemistry, nutrient availability, and ecosystem structure during this hyperthermal event. During periods of extreme or rapid environmental perturbations foraminifera can be poorly preserved. Pteropod identification is equally challenging as aragonitic shells are vulnerable to changing ocean acidity and often only internal molds are left to be identified. The macroscopic rendering of the internal and external test morphology of marine microfossils via 3D printing allows for a more experiential species-recognition education, especially of difficult to identify specimens. A selected microfossil specimen is scanned using computerized tomography (CT), creating x-ray slices of the specimen that are then processed into a digital model. The digitized fossil can then be analyzed using 3D software and subsequently printed using a wide variety of materials. The magnified model can be easily manipulated in a student's hand, and thus can be studied in a more visible and tactile way than traditional methods allow. This invaluable teaching tool physically manifests what was previously limited to textbook images and illustrations or the view field of a microscope. We show the step-by-step 3-D printing process of several PETM marine microfossil specimens from CT scans and demonstrate their advantage over 2-D SEM images for learning to identify microfossils to the species level. In addition, we provide samples to demonstrate the utility of 3-D models in identifying poorly preserved foraminifer specimens and species of pteropods from internal molds.

  5. Existence of two MHD reconnection modes in a solar 3D magnetic null point topology

    Science.gov (United States)

    Pariat, Etienne; Antiochos, Spiro; DeVore, C. Richard; Dalmasse, Kévin

    2012-07-01

    Magnetic topologies with a 3D magnetic null point are common in the solar atmosphere and occur at different spatial scales: such structures can be associated with some solar eruptions, with the so-called pseudo-streamers, and with numerous coronal jets. We have recently developed a series of numerical experiments that model magnetic reconnection in such configurations in order to study and explain the properties of jet-like features. Our model uses our state-of-the-art adaptive-mesh MHD solver ARMS. Energy is injected in the system by line-tied motion of the magnetic field lines in a corona-like configuration. We observe that, in the MHD framework, two reconnection modes eventually appear in the course of the evolution of the system. A very impulsive one, associated with a highly dynamic and fully 3D current sheet, is associated with the energetic generation of a jet. Before and after the generation of the jet, a quasi-steady reconnection mode, more similar to the standard 2D Sweet-Parker model, presents a lower global reconnection rate. We show that the geometry of the magnetic configuration influences the trigger of one or the other mode. We argue that this result carries important implications for the observed link between observational features such as solar jets, solar plumes, and the emission of coronal bright points.

  6. CTCF-Mediated Human 3D Genome Architecture Reveals Chromatin Topology for Transcription

    Science.gov (United States)

    Tang, Zhonghui; Luo, Oscar Junhong; Li, Xingwang; Zheng, Meizhen; Zhu, Jacqueline Jufen; Szalaj, Przemyslaw; Trzaskoma, Pawel; Magalska, Adriana; Wlodarczyk, Jakub; Ruszczycki, Blazej; Michalski, Paul; Piecuch, Emaly; Wang, Ping; Wang, Danjuan; Tian, Simon Zhongyuan; Penrad-Mobayed, May; Sachs, Laurent M.; Ruan, Xiaoan; Wei, Chia-Lin; Liu, Edison T.; Wilczynski, Grzegorz M.; Plewczynski, Dariusz; Li, Guoliang; Ruan, Yijun

    2015-01-01

    Summary Spatial genome organization and its effect on transcription remains a fundamental question. We applied an advanced ChIA-PET strategy to comprehensively map higher-order chromosome folding and specific chromatin interactions mediated by CTCF and RNAPII with haplotype specificity and nucleotide resolution in different human cell lineages. We find that CTCF/cohesin-mediated interaction anchors serve as structural foci for spatial organization of constitutive genes concordant with CTCF-motif orientation, whereas RNAPII interacts within these structures by selectively drawing cell-type-specific genes towards CTCF-foci for coordinated transcription. Furthermore, we show that haplotype-variants and allelic-interactions have differential effects on chromosome configuration influencing gene expression and may provide mechanistic insights into functions associated with disease susceptibility. 3D-genome simulation suggests a model of chromatin folding around chromosomal axes, where CTCF is involved in defining the interface between condensed and open compartments for structural regulation. Our 3D-genome strategy thus provides unique insights in the topological mechanism of human variations and diseases. PMID:26686651

  7. CTCF-Mediated Human 3D Genome Architecture Reveals Chromatin Topology for Transcription.

    Science.gov (United States)

    Tang, Zhonghui; Luo, Oscar Junhong; Li, Xingwang; Zheng, Meizhen; Zhu, Jacqueline Jufen; Szalaj, Przemyslaw; Trzaskoma, Pawel; Magalska, Adriana; Wlodarczyk, Jakub; Ruszczycki, Blazej; Michalski, Paul; Piecuch, Emaly; Wang, Ping; Wang, Danjuan; Tian, Simon Zhongyuan; Penrad-Mobayed, May; Sachs, Laurent M; Ruan, Xiaoan; Wei, Chia-Lin; Liu, Edison T; Wilczynski, Grzegorz M; Plewczynski, Dariusz; Li, Guoliang; Ruan, Yijun

    2015-12-17

    Spatial genome organization and its effect on transcription remains a fundamental question. We applied an advanced chromatin interaction analysis by paired-end tag sequencing (ChIA-PET) strategy to comprehensively map higher-order chromosome folding and specific chromatin interactions mediated by CCCTC-binding factor (CTCF) and RNA polymerase II (RNAPII) with haplotype specificity and nucleotide resolution in different human cell lineages. We find that CTCF/cohesin-mediated interaction anchors serve as structural foci for spatial organization of constitutive genes concordant with CTCF-motif orientation, whereas RNAPII interacts within these structures by selectively drawing cell-type-specific genes toward CTCF foci for coordinated transcription. Furthermore, we show that haplotype variants and allelic interactions have differential effects on chromosome configuration, influencing gene expression, and may provide mechanistic insights into functions associated with disease susceptibility. 3D genome simulation suggests a model of chromatin folding around chromosomal axes, where CTCF is involved in defining the interface between condensed and open compartments for structural regulation. Our 3D genome strategy thus provides unique insights in the topological mechanism of human variations and diseases.

  8. Full-viewpoint 3D Space Object Recognition Based on Kernel Locality Preserving Projections

    Institute of Scientific and Technical Information of China (English)

    Meng Gang; Jiang Zhiguo; Liu Zhengyi; Zhang Haopeng; Zhao Danpei

    2010-01-01

    Space object recognition plays an important role in spatial exploitation and surveillance,followed by two main problems:lacking of data and drastic changes in viewpoints.In this article,firstly,we build a three-dimensional (3D) satellites dataset named BUAA Satellite Image Dataset (BUAA-SID 1.0) to supply data for 3D space object research.Then,based on the dataset,we propose to recognize full-viewpoint 3D space objects based on kemel locality preserving projections (KLPP).To obtain more accurate and separable description of the objects,firstly,we build feature vectors employing moment invariants,Fourier descriptors,region covariance and histogram of oriented gradients.Then,we map the features into kernel space followed by dimensionality reduction using KLPP to obtain the submanifold of the features.At last,k-nearest neighbor (kNN) is used to accomplish the classification.Experimental results show that the proposed approach is more appropriate for space object recognition mainly considering changes of viewpoints.Encouraging recognition rate could be obtained based on images in BUAA-SID 1.0,and the highest recognition result could achieve 95.87%.

  9. Feature, design intention and constraint preservation for direct modeling of 3D freeform surfaces

    Science.gov (United States)

    Fu, Luoting; Kara, Levent Burak; Shimada, Kenji

    2012-06-01

    Direct modeling has recently emerged as a suitable approach for 3D free-form shape modeling in industrial design. It has several advantages over the conventional, parametric modeling techniques, including natural user interactions, as well as the underlying, automatic feature-preserving shape deformation algorithms. However, current direct modeling packages still lack several capabilities critical for product design, such as managing aesthetic design intentions, and enforcing dimensional, geometric constraints. In this paper, we describe a novel 3D surface editing system capable of jointly accommodating aesthetic design intentions expressed in the form of surface painting and color-coded annotations, as well as engineering constraints expressed as dimensions. The proposed system is built upon differential coordinates and constrained least squares, and is intended for conceptual design that involves frequent shape tuning and explorations. We also provide an extensive review of the state-of-the-art direct modeling approaches for 3D mesh-based, freeform surfaces, with an emphasis on the two broad categories of shape deformation algorithms developed in the relevant field of geometric modeling. [Figure not available: see fulltext.

  10. ARPES Study of the 3D Topological Insulator Bi2Se 3

    Science.gov (United States)

    Kim, Ahram

    The 3D topological insulator material Bi2Se3 is characterized with angle-resolved photoemission spectroscopy (ARPES) energy-momentum intensity spectra at various temperatures. High quality samples with relatively small band gaps and a low energy Dirac point were used. An ideal resolution was deter- mined to be taken at photon energy of 11eV. Scattering interaction at the surface can come from three main sources: electron-phonon, surface impurity, or electron-electron scattering, between the surface and the bulk conduction bands. Momemtum- and Energy- Distribution Curves (MDC and EDC) fits were modeled with Gaussian convoluted Lorentzian and extremely-correlated Fermi liquid theory, respectively. By comparing the binding energy at different temperatures for regions near the Fermi edge and near the Dirac point, and observing an increase in MDC self-energy near the Fermi edge, we conclude that a source of interaction is through phonon coupling channels. By calculating the coupling constant ? from self-energy at various temperatures, we present a very low value of ? = 0.049 +/- 0.007 which supports our conclusion that phonon coupling must be incorporated into the theory to provide accurate fit models. Data was taken at beam line 5-4 at the Stanford Synchrotron Radiation Lightsource in Menlo Park, with samples prepared by Genda Gu's group at Brookhaven National Laboratory.

  11. RKKY interaction in P-N junction based on surface states of 3D topological insulator

    Science.gov (United States)

    Zhang, Shuhui; Yang, Wen; Chang, Kai

    The RKKY interaction mediated by conduction electrons supplies a mechanism to realize the long-range coupling of localized spins which is desired for the spin devices. Here, we examine the controllability of RKKY interaction in P-N junction (PNJ) based on surface states of 3D topological insulator (3DTI). In this study, through quantum way but not usual classical analogy to light propagation, the intuitive picture for electron waves across the interface of PNJ is obtained, e.g., Klein tunneling, negative refraction and focusing. Moreover, we perform the numerical calculations for all kinds of RKKY interaction including the Heisenberg, Ising, and Dzyaloshinskii-Moriya terms. We find the focusing of surface states leads to the local augmentation of RKKY interaction. Most importantly, a dimension transition occurs, i.e., the decay rate of RKKY interaction from the deserved 1/R 2 to 1/ R . In addition, the quadratic gate-dependence of RKKY interaction is also beneficial to the application of 3DTI PNJ in the fields of spintronics and quantum computation. This work was supported by the MOST (Grant No. 2015CB921503, and No. 2014CB848700) and NSFC (Grant No. 11434010, No. 11274036, No. 11322542, and No. 11504018).

  12. ROI-preserving 3D video compression method utilizing depth information

    Science.gov (United States)

    Ti, Chunli; Xu, Guodong; Guan, Yudong; Teng, Yidan

    2015-09-01

    Efficiently transmitting the extra information of three dimensional (3D) video is becoming a key issue of the development of 3DTV. 2D plus depth format not only occupies the smaller bandwidth and is compatible transmission under the condition of the existing channel, but also can provide technique support for advanced 3D video compression in some extend. This paper proposes an ROI-preserving compression scheme to further improve the visual quality at a limited bit rate. According to the connection between the focus of Human Visual System (HVS) and depth information, region of interest (ROI) can be automatically selected via depth map progressing. The main improvement from common method is that a meanshift based segmentation is executed to the depth map before foreground ROI selection to keep the integrity of scene. Besides, the sensitive areas along the edges are also protected. The Spatio-temporal filtering adapting to H.264 is used to the non-ROI of both 2D video and depth map before compression. Experiments indicate that, the ROI extracted by this method is more undamaged and according with subjective feeling, and the proposed method can keep the key high-frequency information more effectively while the bit rate is reduced.

  13. 具有3D边缘保持的网面简化算法%Mesh Simplification with 3D Edge Preservation

    Institute of Scientific and Technical Information of China (English)

    刘万春; 贾云得; 朱玉文; 李莉; 李科杰

    2001-01-01

    Mesh simplification of 3D models for computer vision applications should preserve its shape, topology and other attribute values of the object. This calls for a vision system to be effective in the presentation, description, recognition and understanding of the object. A mesh simplification algorithm with features of 3D edge preservation by applying edge operations, e dge-collapse and edge-split to the whole surface mesh is proposed. The maximum asymmetric distance between two meshes is calculated as the shape change measur e. The proposed algorithm is able to reduce a number of faces while preserving t he object's shape, its topology and 3D edge features. The algorithm also distr ibutes the vertices of the mesh evenly over the surface of the object.%研究用于计算机视觉领域的三维物体模型网面简化算法。该算法 可保持物体形状和拓扑关系及物体表面法线、纹理、颜色和边缘等特征,是一种基于边操作 (收缩,分裂)的网面模型的简化算法。该算法将网面不对称最大距离作为形状改变测度,在 大量简化模型数据的同时,能有效地保持模型几何形状、拓扑关系、3D边缘点和边的特 征,并能合理分布网面特点。

  14. Topology optimization of 3D compliant actuators by a sequential element rejection and admission method

    OpenAIRE

    Ansola, R; Vegueria, E; Alonso, C.; Querin, OM

    2016-01-01

    This work presents a sequential element rejection and admission (SERA) method for optimum topology design of three dimensional compliant actuators. The proposed procedure has been successfully applied to several topology optimization problems, but most investigations for compliant devices design have been focused on planar systems. This investigation aims to progress on this line, where a generalization of the method for three dimensional topology optimization is explored. The methodology des...

  15. Layer Construction of 3D Topological States and String Braiding Statistics

    Directory of Open Access Journals (Sweden)

    Chao-Ming Jian

    2014-12-01

    Full Text Available While the topological order in two dimensions has been studied extensively since the discovery of the integer and fractional quantum Hall systems, topological states in three spatial dimensions are much less understood. In this paper, we propose a general formalism for constructing a large class of three-dimensional topological states by stacking layers of 2D topological states and introducing coupling between them. Using this construction, different types of topological states can be obtained, including those with only surface topological order and no bulk topological quasiparticles, and those with topological order both in the bulk and at the surface. For both classes of states, we study its generic properties and present several explicit examples. As an interesting consequence of this construction, we obtain example systems with nontrivial braiding statistics between string excitations. In addition to studying the string-string braiding in the example system, we propose a topological field-theory description for the layer-constructed systems, which captures not only the string-particle braiding statistics but also the string-string braiding statistics when the coupling is twisted. Last, we provide a proof of a general identity for Abelian string statistics and discuss an example system with non-Abelian strings.

  16. Triangulated manifold meshing method preserving molecular surface topology.

    Science.gov (United States)

    Chen, Minxin; Tu, Bin; Lu, Benzhuo

    2012-09-01

    Generation of manifold mesh is an urgent issue in mathematical simulations of biomolecule using boundary element methods (BEM) or finite element method (FEM). Defects, such as not closed mesh, intersection of elements and missing of small structures, exist in surface meshes generated by most of the current meshing method. Usually the molecular surface meshes produced by existing methods need to be revised carefully by third party software to ensure the surface represents a continuous manifold before being used in a BEM and FEM calculations. Based on the trace technique proposed in our previous work, in this paper, we present an improved meshing method to avoid intersections and preserve the topology of the molecular Gaussian surface. The new method divides the whole Gaussian surface into single valued pieces along each of x, y, z directions by tracing the extreme points along the fold curves on the surface. Numerical test results show that the surface meshes produced by the new method are manifolds and preserve surface topologies. The result surface mesh can also be directly used in surface conforming volume mesh generation for FEM type simulation. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Quality Criteria for Architectural 3D Data in Usage and Preservation Processes

    DEFF Research Database (Denmark)

    Lindlar, Michelle; Tamke, Martin; Myrup Jensen, Morten

    2014-01-01

    responsible for the archival of information about publically funded buildings. Architectural practise of today commonly includes 3D object processing. The output of these processes is slowly reaching the aforementioned cultural heritage institutions which are now facing the task of quality assessment...... of the material. The paper will present a first analysis of potential quality factors and compare architectural and cultural heritage domain expectations in 3D data quality. It will look at two forms of 3D data: modelled 3D objects and scanned 3D objects. The work presented in this paper is based on work......Quality assessment of digital material has been just one of the new tasks the digital revolution brought into the library domain. With the first big print material digitization efforts in the digital heritage domain dating back to the 1980ies, plenty of experience has been gathered...

  18. Quality Criteria for Architectural 3D Data in Usage and Preservation Processes

    DEFF Research Database (Denmark)

    Lindlar, Michelle; Tamke, Martin; Myrup Jensen, Morten

    2014-01-01

    responsible for the archival of information about publically funded buildings. Architectural practise of today commonly includes 3D object processing. The output of these processes is slowly reaching the aforementioned cultural heritage institutions which are now facing the task of quality assessment...... of the material. The paper will present a first analysis of potential quality factors and compare architectural and cultural heritage domain expectations in 3D data quality. It will look at two forms of 3D data: modelled 3D objects and scanned 3D objects. The work presented in this paper is based on work......Quality assessment of digital material has been just one of the new tasks the digital revolution brought into the library domain. With the first big print material digitization efforts in the digital heritage domain dating back to the 1980ies, plenty of experience has been gathered...

  19. Ripple-modulated electronic structure of a 3D topological insulator.

    Science.gov (United States)

    Okada, Yoshinori; Zhou, Wenwen; Walkup, D; Dhital, Chetan; Wilson, Stephen D; Madhavan, V

    2012-01-01

    Three-dimensional topological insulators host linearly dispersing states with unique properties and a strong potential for applications. An important ingredient in realizing some of the more exotic states in topological insulators is the ability to manipulate local electronic properties. Direct analogy to the Dirac material graphene suggests that a possible avenue for controlling local properties is via a controlled structural deformation such as the formation of ripples. However, the influence of such ripples on topological insulators is yet to be explored. Here we use scanning tunnelling microscopy to determine the effects of one-dimensional buckling on the electronic properties of Bi(2)Te(3.) By tracking spatial variations of the interference patterns generated by the Dirac electrons we show that buckling imposes a periodic potential, which locally modulates the surface-state dispersion. This suggests that forming one- and two-dimensional ripples is a viable method for creating nanoscale potential landscapes that can be used to control the properties of Dirac electrons in topological insulators.

  20. Metadata and Tools for Integration and Preservation of Cultural Heritage 3D Information

    Directory of Open Access Journals (Sweden)

    Achille Felicetti

    2011-12-01

    Full Text Available In this paper we investigate many of the various storage, portability and interoperability issues arising among archaeologists and cultural heritage people when dealing with 3D technologies. On the one side, the available digital repositories look often unable to guarantee affordable features in the management of 3D models and their metadata; on the other side the nature of most of the available data format for 3D encoding seem to be not satisfactory for the necessary portability required nowadays by 3D information across different systems. We propose a set of possible solutions to show how integration can be achieved through the use of well known and wide accepted standards for data encoding and data storage. Using a set of 3D models acquired during various archaeological campaigns and a number of open source tools, we have implemented a straightforward encoding process to generate meaningful semantic data and metadata. We will also present the interoperability process carried out to integrate the encoded 3D models and the geographic features produced by the archaeologists. Finally we will report the preliminary (rather encouraging development of a semantic enabled and persistent digital repository, where 3D models (but also any kind of digital data and metadata can easily be stored, retrieved and shared with the content of other digital archives.

  1. Topology preserving non-rigid image registration using time-varying elasticity model for MRI brain volumes.

    Science.gov (United States)

    Ahmad, Sahar; Khan, Muhammad Faisal

    2015-12-01

    In this paper, we present a new non-rigid image registration method that imposes a topology preservation constraint on the deformation. We propose to incorporate the time varying elasticity model into the deformable image matching procedure and constrain the Jacobian determinant of the transformation over the entire image domain. The motion of elastic bodies is governed by a hyperbolic partial differential equation, generally termed as elastodynamics wave equation, which we propose to use as a deformation model. We carried out clinical image registration experiments on 3D magnetic resonance brain scans from IBSR database. The results of the proposed registration approach in terms of Kappa index and relative overlap computed over the subcortical structures were compared against the existing topology preserving non-rigid image registration methods and non topology preserving variant of our proposed registration scheme. The Jacobian determinant maps obtained with our proposed registration method were qualitatively and quantitatively analyzed. The results demonstrated that the proposed scheme provides good registration accuracy with smooth transformations, thereby guaranteeing the preservation of topology.

  2. Topological defect launches 3D mound in the active nematic sheet of neural progenitors

    CERN Document Server

    Kawaguchi, Kyogo; Sano, Masaki

    2016-01-01

    Cultured stem cells have become a standard platform not only for regenerative medicine and developmental biology but also for biophysical studies. Yet, the characterization of cultured stem cells at the level of morphology and macroscopic patterns resulting from cell-to-cell interactions remain largely qualitative, even though they are the simplest features observed in everyday experiments. Here we report that neural progenitor cells (NPCs), which are multipotent stem cells that give rise to cells in the central nervous system, rapidly glide and stochastically reverse its velocity while locally aligning with neighboring cells, thus showing features of an active nematic system. Within the two-dimensional nematic pattern, we find interspaced topological defects with +1/2 and -1/2 charges. Remarkably, we identified rapid cell accumulation leading to three-dimensional mounds at the +1/2 topological defects. Single-cell level imaging around the defects allowed quantification of the evolving cell density, clarifyin...

  3. From 3D topological quantum field theories to 4D models with defects

    Science.gov (United States)

    Delcamp, Clement; Dittrich, Bianca

    2017-06-01

    (2 + 1) dimensional topological quantum field theories (TQFTs) with defect excitations are by now quite well understood, while many questions are still open for (3 + 1) dimensional TQFTs. Here we propose a strategy to lift states and operators of a (2 + 1) dimensional TQFT to states and operators of a (3 + 1) dimensional theory with defects. The main technical tool is Heegaard splittings, which allow us to encode the topology of a three-dimensional manifold with line defects into a two-dimensional Heegaard surface. We apply this idea to the example of BF theory which describes locally flat connections. This shows in particular how the curvature excitation generating surface operators of the (3 + 1) dimensional theory can be obtained from closed ribbon operators of the (2 + 1) dimensional BF theory. We hope that this technique allows the construction and study of more general models based on unitary fusion categories.

  4. Topology-preserving flocking of nonlinear agents using optimistic planning

    Institute of Scientific and Technical Information of China (English)

    Lucian BU SONIU; Irinel-Constantin MORARESCU

    2015-01-01

    We consider the generalized flocking problem in multiagent systems, where the agents must drive a subset of their state variables to common values, while communication is constrained by a proximity relationship in terms of another subset of variables. We build a flocking method for general nonlinear agent dynamics, by using at each agent a near-optimal control technique from artificial intelligence called optimistic planning. By defining the rewards to be optimized in a well-chosen way, the preservation of the interconnection topology is guaranteed, under a controllability assumption. We also give a practical variant of the algorithm that does not require to know the details of this assumption, and show that it works well in experiments on nonlinear agents.

  5. In vivo biomarker expression patterns are preserved in 3D cultures of Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Windus, Louisa C.E.; Kiss, Debra L.; Glover, Tristan [Eskitis Institute for Cell and Molecular Therapies, Discovery Biology, Griffith University, Nathan 4111, Brisbane, Queensland (Australia); Avery, Vicky M., E-mail: v.avery@griffith.edu.au [Eskitis Institute for Cell and Molecular Therapies, Discovery Biology, Griffith University, Nathan 4111, Brisbane, Queensland (Australia)

    2012-11-15

    Here we report that Prostate Cancer (PCa) cell-lines DU145, PC3, LNCaP and RWPE-1 grown in 3D matrices in contrast to conventional 2D monolayers, display distinct differences in cell morphology, proliferation and expression of important biomarker proteins associated with cancer progression. Consistent with in vivo growth rates, in 3D cultures, all PCa cell-lines were found to proliferate at significantly lower rates in comparison to their 2D counterparts. Moreover, when grown in a 3D matrix, metastatic PC3 cell-lines were found to mimic more precisely protein expression patterns of metastatic tumour formation as found in vivo. In comparison to the prostate epithelial cell-line RWPE-1, metastatic PC3 cell-lines exhibited a down-regulation of E-cadherin and {alpha}6 integrin expression and an up-regulation of N-cadherin, Vimentin and {beta}1 integrin expression and re-expressed non-transcriptionally active AR. In comparison to the non-invasive LNCaP cell-lines, PC3 cells were found to have an up-regulation of chemokine receptor CXCR4, consistent with a metastatic phenotype. In 2D cultures, there was little distinction in protein expression between metastatic, non-invasive and epithelial cells. These results suggest that 3D cultures are more representative of in vivo morphology and may serve as a more biologically relevant model in the drug discovery pipeline. -- Highlights: Black-Right-Pointing-Pointer We developed and optimised 3D culturing techniques for Prostate Cancer cell-lines. Black-Right-Pointing-Pointer We investigated biomarker expression in 2D versus 3D culture techniques. Black-Right-Pointing-Pointer Metastatic PC3 cells re-expressed non-transcriptionally active androgen receptor. Black-Right-Pointing-Pointer Metastatic PCa cell lines retain in vivo-like antigenic profiles in 3D cultures.

  6. A Domain-Driven Approach to Digital Curation and Preservation of 3D Architectural Data

    DEFF Research Database (Denmark)

    Lindlar, Michelle; Tamke, Martin

    2014-01-01

    and geometric enrichment, consistent naming schemas and ontologies, as well as pre-ingest tasks in OAIS compliant digital preservation workflows. In a first step, the project identified stakeholders for methods and processes. Since the project strives for a holistic digital preservation approach, different...

  7. Towards Automatic and Topologically Consistent 3D Regional Geological Modeling from Boundaries and Attitudes

    Directory of Open Access Journals (Sweden)

    Jiateng Guo

    2016-02-01

    Full Text Available Three-dimensional (3D geological models are important representations of the results of regional geological surveys. However, the process of constructing 3D geological models from two-dimensional (2D geological elements remains difficult and is not necessarily robust. This paper proposes a method of migrating from 2D elements to 3D models. First, the geological interfaces were constructed using the Hermite Radial Basis Function (HRBF to interpolate the boundaries and attitude data. Then, the subsurface geological bodies were extracted from the spatial map area using the Boolean method between the HRBF surface and the fundamental body. Finally, the top surfaces of the geological bodies were constructed by coupling the geological boundaries to digital elevation models. Based on this workflow, a prototype system was developed, and typical geological structures (e.g., folds, faults, and strata were simulated. Geological modes were constructed through this workflow based on realistic regional geological survey data. The model construction process was rapid, and the resulting models accorded with the constraints of the original data. This method could also be used in other fields of study, including mining geology and urban geotechnical investigations.

  8. Comparing 2D pictures with 3D replicas for the digital preservation and analysis of tangible heritage.

    OpenAIRE

    Galeazzi, Fabrizio; Di Giuseppantonio Di Franco, Paola; Matthews, Justin L.

    2015-01-01

    This is the author accepted manuscript. The final version is available from Taylor & Francis via http://dx.doi.org/10.1080/09647775.2015.1042515 In this paper, we present two experiments designed to compare 2D digital pictures and 3D digital replicas of artefacts, to understand how differently these media facilitate the perception and understanding of our past. Archaeologists and museum experts have commonly used 2D digital pictures to preserve and study artefacts. Recently these scholars ...

  9. Studying topological structure of 21-cm line fluctuations with 3D Minkowski functionals before reionization

    Science.gov (United States)

    Yoshiura, Shintaro; Shimabukuro, Hayato; Takahashi, Keitaro; Matsubara, Takahiko

    2017-02-01

    The brightness temperature of the redshifted 21-cm line brings rich information about the intergalactic medium (IGM) from the cosmic dawn and epoch of reionization (EoR). While the power spectrum is a useful tool to investigate the 21-cm signal statistically, the 21-cm brightness temperature field is highly non-Gaussian and the power spectrum is inadequate to characterize the non-Gaussianity. Minkowski functionals (MFs) are promising tools to extract non-Gaussian features of the 21-cm signal and give topological information, such as morphology of ionized bubbles. In this work, we study the 21-cm line signal in detail with MFs. To promote understanding of basic features of the 21-cm signal, we calculate the MFs of not only the hydrogen neutral fraction but also the matter density and spin temperature, which contribute to brightness-temperature fluctuations. We find that the structure of the brightness temperature depends mainly on the ionized fraction and the spin temperature at late and early stages of the EoR, respectively. Further, we investigate the redshift evolution of MFs at 7 topology of ionized bubbles and we consider the possibility of constraining the parameters using future 21-cm signal observations.

  10. A 3D modeling and measurement system for cultural heritage preservation

    Science.gov (United States)

    Du, Guoguang; Zhou, Mingquan; Ren, Pu; Shui, Wuyang; Zhou, Pengbo; Wu, Zhongke

    2015-07-01

    Cultural Heritage reflects the human production, life style and environmental conditions of various historical periods. It exists as one of the major national carriers of national history and culture. In order to do better protection and utilization for these cultural heritages, a system of three-dimensional (3D) reconstruction and statistical measurement is proposed in this paper. The system solves the problems of cultural heritage's data storage, measurement and analysis. Firstly, for the high precision modeling and measurement problems, range data registration and integration algorithm used to achieve high precision 3D reconstruction. Secondly, multi-view stereo reconstruction method is used to solve the problem of rapid reconstruction by procedures such as the original image data pre-processing, camera calibration, point cloud modeling. At last, the artifacts' measure underlying database is established by calculating the measurements of the 3D model's surface. These measurements contain Euclidean distance between the points on the surface, geodesic distance between the points, normal and curvature in each point, superficial area of a region, volume of model's part and some other measurements. These measurements provide a basis for carrying out information mining of cultural heritage. The system has been applied to the applications of 3D modeling, data measurement of the Terracotta Warriors relics, Tibetan architecture and some other relics.

  11. Effects of 2D and 3D Error Fields on the SAS Divertor Magnetic Topology

    Science.gov (United States)

    Trevisan, G. L.; Lao, L. L.; Strait, E. J.; Guo, H. Y.; Wu, W.; Evans, T. E.

    2016-10-01

    The successful design of plasma-facing components in fusion experiments is of paramount importance in both the operation of future reactors and in the modification of operating machines. Indeed, the Small Angle Slot (SAS) divertor concept, proposed for application on the DIII-D experiment, combines a small incident angle at the plasma strike point with a progressively opening slot, so as to better control heat flux and erosion in high-performance tokamak plasmas. Uncertainty quantification of the error fields expected around the striking point provides additional useful information in both the design and the modeling phases of the new divertor, in part due to the particular geometric requirement of the striking flux surfaces. The presented work involves both 2D and 3D magnetic error field analysis on the SAS strike point carried out using the EFIT code for 2D equilibrium reconstruction, V3POST for vacuum 3D computations and the OMFIT integrated modeling framework for data analysis. An uncertainty in the magnetic probes' signals is found to propagate non-linearly as an uncertainty in the striking point and angle, which can be quantified through statistical analysis to yield robust estimates. Work supported by contracts DE-FG02-95ER54309 and DE-FC02-04ER54698.

  12. Monte Carlo Study of Topological Defects in the 3D Heisenberg Model

    CERN Document Server

    Holm, C; Holm, Christian; Janke, Wolfhard

    1994-01-01

    We use single-cluster Monte Carlo simulations to study the role of topological defects in the three-dimensional classical Heisenberg model on simple cubic lattices of size up to $80^3$. By applying reweighting techniques to time series generated in the vicinity of the approximate infinite volume transition point $K_c$, we obtain clear evidence that the temperature derivative of the average defect density $d\\langle n \\rangle/dT$ behaves qualitatively like the specific heat, i.e., both observables are finite in the infinite volume limit. This is in contrast to results by Lau and Dasgupta [{\\em Phys. Rev.\\/} {\\bf B39} (1989) 7212] who extrapolated a divergent behavior of $d\\langle n \\rangle/dT$ at $K_c$ from simulations on lattices of size up to $16^3$. We obtain weak evidence that $d\\langle n \\rangle/dT$ scales with the same critical exponent as the specific heat.As a byproduct of our simulations, we obtain a very accurate estimate for the ratio $\\alpha/\

  13. A novel 3D framework indium phosphite-oxalate based on a pcu-type topology

    Science.gov (United States)

    Zuo, Mengmeng; Zhou, Mingdong; Hu, Dianwen; Gao, Fan; Dong, Sijie; Huang, Liangliang

    2016-05-01

    A new inorganic-organic hybrid indium phosphite-oxalate, formulated as H[In5(HPO3)6(H2PO3)2(C2O4)2]·(C4N2H11)2·H2O 1 has been hydrothermally synthesized in the presence of piperazine acting as a structure directing agent (SDA). The single crystal X-ray diffraction reveals that compound 1 shows three-dimensional open-framework with intersecting 12-ring channels along the [010] and [001] directions, which is constructed from strictly alternating double 6-ring units (D6Rs), [C2O4]2- groups and [H2PO3]- pseudo-pyramids. It is noted that the classical D6R SBU is firstly reported in main metal phosphite/phosphite-oxalate. By regarding D6R as the 6-connected nodes, the inorganic-organic hybrid framework is based on a pcu-type topology. The as-synthesized product was characterized by single-crystal X-ray diffraction, powder X-ray diffraction, IR spectroscopy, thermogravimetric analysis (TGA), ICP-AES and elemental analyses.

  14. Design of Mott and topological phases on buckled 3d-oxide honeycomb lattices

    Science.gov (United States)

    Pentcheva, Rossitza

    The honeycomb lattice, as realized e.g. in graphene, has rendered a robust platform for innovative science and potential applications. A much richer generalization of this lattice arises in (111)-oriented bilayers of perovskites, adding the complexity of the strongly correlated, multiorbital nature of electrons in transition metal oxides. Based on first principles calculations with an on-site Coulomb repulsion, here we provide trends in the evolution of ground states versus band filling in (111)-oriented (La XO3)2 /(LaAlO3)4 superlattices, with X spanning the entire 3d transition metal series. The competition between local quasi-cubic and global triangular symmetry triggers unanticipated broken symmetry phases, with mechanisms ranging from Jahn-Teller distortion, to charge-, spin-, and orbital-ordering. LaMnO3 and LaCoO3 bilayers, where spin-orbit coupling opens a sizable gap in the Dirac-point Fermi surface, emerge as much desired oxide-based Chern insulators, the latter displaying a gap capable of supporting room-temperature applications Further realizations of the honeycomb lattice and geometry patterns beyond the perovskite structure will be addressed. Research supported by the DFG, SFB/TR80.

  15. THE ARCHITECTURAL INFORMATION SYSTEM SIARCH3D-UNIVAQ FOR ANALYSIS AND PRESERVATION OF ARCHITECTURAL HERITAGE

    Directory of Open Access Journals (Sweden)

    M. Centofanti

    2012-09-01

    Full Text Available The research group of L'Aquila University defined a procedure to create an architectonical Information System called SIArch- Univaq. This information system can be integrated with "Risk Map" Italian database. The SIArch-Univaq is based on importation of architectonical three-dimensional photorealistic models in GIS environment. 3D models are realised according to building constructive elements, derived by a critical architectonic surveying; the importation of models into GIS allows the interrogation of the constructive elements (i.e. beam, window, door, etc.: this favour the knowledge of the architectonical heritage, indispensable requirement to plan processes of restoration, maintenance and management.

  16. 3D prostate MR-TRUS non-rigid registration using dual optimization with volume-preserving constraint

    Science.gov (United States)

    Qiu, Wu; Yuan, Jing; Fenster, Aaron

    2016-03-01

    We introduce an efficient and novel convex optimization-based approach to the challenging non-rigid registration of 3D prostate magnetic resonance (MR) and transrectal ultrasound (TRUS) images, which incorporates a new volume preserving constraint to essentially improve the accuracy of targeting suspicious regions during the 3D TRUS guided prostate biopsy. Especially, we propose a fast sequential convex optimization scheme to efficiently minimize the employed highly nonlinear image fidelity function using the robust multi-channel modality independent neighborhood descriptor (MIND) across the two modalities of MR and TRUS. The registration accuracy was evaluated using 10 patient images by calculating the target registration error (TRE) using manually identified corresponding intrinsic fiducials in the whole prostate gland. We also compared the MR and TRUS manually segmented prostate surfaces in the registered images in terms of the Dice similarity coefficient (DSC), mean absolute surface distance (MAD), and maximum absolute surface distance (MAXD). Experimental results showed that the proposed method with the introduced volume-preserving prior significantly improves the registration accuracy comparing to the method without the volume-preserving constraint, by yielding an overall mean TRE of 2:0+/-0:7 mm, and an average DSC of 86:5+/-3:5%, MAD of 1:4+/-0:6 mm and MAXD of 6:5+/-3:5 mm.

  17. Synthesis, structure and luminescent property of a new 3D porous metal organic framework with rutile topology

    Science.gov (United States)

    Zhao, Jin; Zhu, Guang-Shan; Zou, Yong-Cun; Fang, Qian-Rong; Xue, Ming; Li, Zhong-Yue; Qiu, Shi-Lun

    2007-12-01

    A new 3D porous metal-organic framework (MOF), Cd(CTC)(HPDA)·(H 2O) ( 1) (CTC = cis, cis-1,3,5-cyclohexanetricarboxylate and PDA = 1,3-propanediamine) has been synthesized by using an organic amine, PDA, as a template. X-ray crystallography reveals that two cadmium centers are coordinated by six different carboxylate groups to construct a dinuclear octahedral secondary building unit (SBU), and these octahedral SBUs are further interconnected by the cyclohexane rings of CTC to generate a 3D network with quadrangular channel dimensions of ca. 10 × 17 Å 2. In this structure, the dinuclear octahedral SBU can be defined as a 6-connected node, and CTC ligating with three SBUs can act as a 3-connected node. So the resulting structure of 1 is a binodal (3,6)-connected net with rutile topology. Additionally, polymer 1 exhibits intense fluorescence at 364 nm with the excitation peak at 240 nm in the solid state at room temperature.

  18. Static and dynamic fatigue behavior of topology designed and conventional 3D printed bioresorbable PCL cervical interbody fusion devices.

    Science.gov (United States)

    Knutsen, Ashleen R; Borkowski, Sean L; Ebramzadeh, Edward; Flanagan, Colleen L; Hollister, Scott J; Sangiorgio, Sophia N

    2015-09-01

    Recently, as an alternative to metal spinal fusion cages, 3D printed bioresorbable materials have been explored; however, the static and fatigue properties of these novel cages are not well known. Unfortunately, current ASTM testing standards used to determine these properties were designed prior to the advent of bioresorbable materials for cages. Therefore, the applicability of these standards for bioresorbable materials is unknown. In this study, an image-based topology and a conventional 3D printed bioresorbable poly(ε)-caprolactone (PCL) cervical cage design were tested in compression, compression-shear, and torsion, to establish their static and fatigue properties. Difficulties were in fact identified in establishing failure criteria and in particular determining compressive failure load. Given these limitations, under static loads, both designs withstood loads of over 650 N in compression, 395 N in compression-shear, and 0.25 Nm in torsion, prior to yielding. Under dynamic testing, both designs withstood 5 million (5M) cycles of compression at 125% of their respective yield forces. Geometry significantly affected both the static and fatigue properties of the cages. The measured compressive yield loads fall within the reported physiological ranges; consequently, these PCL bioresorbable cages would likely require supplemental fixation. Most importantly, supplemental testing methods may be necessary beyond the current ASTM standards, to provide more accurate and reliable results, ultimately improving preclinical evaluation of these devices. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Defect energetics and magnetic properties of 3 d-transition-metal-doped topological crystalline insulator SnTe

    Science.gov (United States)

    Wang, Na; Wang, JianFeng; Si, Chen; Gu, Bing-Lin; Duan, WenHui

    2016-08-01

    The introduction of magnetism in SnTe-class topological crystalline insulators is a challenging subject with great importance in the quantum device applications. Based on the first-principles calculations, we have studied the defect energetics and magnetic properties of 3 d transition-metal (TM)-doped SnTe. We find that the doped TM atoms prefer to stay in the neutral states and have comparatively high formation energies, suggesting that the uniform TMdoping in SnTe with a higher concentration will be difficult unless clustering. In the dilute doping regime, all the magnetic TMatoms are in the high-spin states, indicating that the spin splitting energy of 3 d TM is stronger than the crystal splitting energy of the SnTe ligand. Importantly, Mn-doped SnTe has relatively low defect formation energy, largest local magnetic moment, and no defect levels in the bulk gap, suggesting that Mn is a promising magnetic dopant to realize the magnetic order for the theoretically-proposed large-Chern-number quantum anomalous Hall effect (QAHE) in SnTe.

  20. Fabrication of 3D-culture platform with sandwich architecture for preserving liver-specific functions of hepatocytes using 3D bioprinter.

    Science.gov (United States)

    Arai, Kenichi; Yoshida, Toshiko; Okabe, Motonori; Goto, Mitsuaki; Mir, Tanveer Ahmad; Soko, Chika; Tsukamoto, Yoshinari; Akaike, Toshihiro; Nikaido, Toshio; Zhou, Kaixuan; Nakamura, Makoto

    2017-06-01

    The development of new three-dimensional (3D) cell culture system that maintains the physiologically relevant signals of hepatocytes is essential in drug discovery and tissue engineering research. Conventional two-dimensional (2D) culture yields cell growth, proliferation, and differentiation. However, gene expression and signaling profiles can be different from in vivo environment. Here, we report the fabrication of a 3D culture system using an artificial scaffold and our custom-made inkjet 3D bioprinter as a new strategy for studying liver-specific functions of hepatocytes. We built a 3D culture platform for hepatocytes-attachment and formation of cell monolayer by interacting the galactose chain of galactosylated alginate gel (GA-gel) with asialoglycoprotein receptor (ASGPR) of hepatocytes. The 3D geometrical arrangement of cells was controlled by using 3D bioprinter, and cell polarity was controlled with the galactosylated hydrogels. The fabricated GA-gel was able to successfully promote adhesion of hepatocytes. To observe liver-specific functions and to mimic hepatic cord, an additional parallel layer of hepatocytes was generated using two gel sheets. These results indicated that GA-gel biomimetic matrices can be used as a 3D culture system that could be effective for the engineering of liver tissues. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1583-1592, 2017. © 2017 Wiley Periodicals, Inc.

  1. Preservation of protein fluorescence in embedded human dendritic cells for targeted 3D light and electron microscopy.

    Science.gov (United States)

    Höhn, K; Fuchs, J; Fröber, A; Kirmse, R; Glass, B; Anders-Össwein, M; Walther, P; Kräusslich, H-G; Dietrich, C

    2015-08-01

    In this study, we present a correlative microscopy workflow to combine detailed 3D fluorescence light microscopy data with ultrastructural information gained by 3D focused ion beam assisted scanning electron microscopy. The workflow is based on an optimized high pressure freezing/freeze substitution protocol that preserves good ultrastructural detail along with retaining the fluorescence signal in the resin embedded specimens. Consequently, cellular structures of interest can readily be identified and imaged by state of the art 3D confocal fluorescence microscopy and are precisely referenced with respect to an imprinted coordinate system on the surface of the resin block. This allows precise guidance of the focused ion beam assisted scanning electron microscopy and limits the volume to be imaged to the structure of interest. This, in turn, minimizes the total acquisition time necessary to conduct the time consuming ultrastructural scanning electron microscope imaging while eliminating the risk to miss parts of the target structure. We illustrate the value of this workflow for targeting virus compartments, which are formed in HIV-pulsed mature human dendritic cells. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  2. Geometric and topological feature extraction of linear segments from 2D cross-section data of 3D point clouds

    Science.gov (United States)

    Ramamurthy, Rajesh; Harding, Kevin; Du, Xiaoming; Lucas, Vincent; Liao, Yi; Paul, Ratnadeep; Jia, Tao

    2015-05-01

    Optical measurement techniques are often employed to digitally capture three dimensional shapes of components. The digital data density output from these probes range from a few discrete points to exceeding millions of points in the point cloud. The point cloud taken as a whole represents a discretized measurement of the actual 3D shape of the surface of the component inspected to the measurement resolution of the sensor. Embedded within the measurement are the various features of the part that make up its overall shape. Part designers are often interested in the feature information since those relate directly to part function and to the analytical models used to develop the part design. Furthermore, tolerances are added to these dimensional features, making their extraction a requirement for the manufacturing quality plan of the product. The task of "extracting" these design features from the point cloud is a post processing task. Due to measurement repeatability and cycle time requirements often automated feature extraction from measurement data is required. The presence of non-ideal features such as high frequency optical noise and surface roughness can significantly complicate this feature extraction process. This research describes a robust process for extracting linear and arc segments from general 2D point clouds, to a prescribed tolerance. The feature extraction process generates the topology, specifically the number of linear and arc segments, and the geometry equations of the linear and arc segments automatically from the input 2D point clouds. This general feature extraction methodology has been employed as an integral part of the automated post processing algorithms of 3D data of fine features.

  3. Andreev reflection through a junction of a 3D topological insulator and an s-wave superconductor

    Science.gov (United States)

    Chen, Son-Hsien; Sun, Shih-Jye

    2016-12-01

    We examine the retro and specular Andreev reflections (ARs) through a junction consisting of a three-dimensional (3D) Bi2Se3 topological insulator (TI) and an s-wave superconductor (SC) using spatially-resolved nonequilibrium Green function formalism in Nambu space. A 3DTI Bogoliubov-de Gennes Hamiltonian is constructed. The retro (specular) AR is identified by the spatial distribution of charge (spin-y) current. When approaching the interface, unlike the specular AR, the retro AR exhibits a large amount of net charge flow near the top surface of the 3DTI. In the specular AR, a large parallel component of the spin-y flow is developed in the interface, which is not found in the retro AR. Diminished charge currents are found near the onset of the specular AR. The AR mechanism enhances the current-induced spin-y polarization flowing through the junction interface. In the TI phase, larger normal-transmission conductance {{G}\\text{NT}} in the normal-metal junction yields larger AR conductance {{G}\\text{AR}} in the corresponding SC junction. The Zeeman splitting perpendicular to the quintuple layers partially (completely) suppresses the {{G}\\text{AR}} in the finite (infinite thick) TI.

  4. Multiple endpoint analysis of BAC-preserved and unpreserved antiallergic eye drops on a 3D-reconstituted corneal epithelial model

    OpenAIRE

    Pauly, A.; Brasnu, E.; Riancho, L.; Brignole-Baudouin, F.; Baudouin, C

    2011-01-01

    Purpose To compare the effects of benzalkonium chloride (BAC)-preserved and unpreserved antiallergic eye drops on the human 3D-reconstituted corneal epithelial model (3D-HCE). Methods 3D-HCE were treated for 24 h followed or not by a 24 h post-incubation recovery period (24 h+24 h) with phosphate-buffered saline (PBS), 0.01% BAC, unpreserved formulations of ketotifen, N Acetyl-Aspartyl Glutamic Acid (NAAGA), cromoglycate, or BAC-preserved commercial formulations of ketotifen, olopatadine, epi...

  5. Derivation of Hillert-type 3D grain growth rate model with topological considerations and discussion on its grain size parameter

    Institute of Scientific and Technical Information of China (English)

    Guoquan Liu; Haibo Yu; Xiaoyan Song; Xiangge Qin; Chao Wang

    2004-01-01

    A Hillert-type three-dimensional grain growth rate model was derived through the grain topology-size correlation model,combined with a topology-dependent grain growth rate equation in three dimensions. It shows clearly that the Hillert-type 3D grain growth rate model may also be described with topology considerations of microstructure. The size parameter bearing in the model is further discussed both according to the derived model and in another approach with the aid of quantitative relationship between the grain size and the integral mean curvature over grain surface. Both approaches successfully demonstrate that, if the concerned grains can be well approximated by a space-filling convex polyhedra in shape, the grain size parameter bearing in the Hillert-type 3D grain growth model should be a parameter proportional to the mean grain tangent radius.

  6. Scalable and Detail-Preserving Ground Surface Reconstruction from Large 3D Point Clouds Acquired by Mobile Mapping Systems

    Science.gov (United States)

    Craciun, D.; Serna Morales, A.; Deschaud, J.-E.; Marcotegui, B.; Goulette, F.

    2014-08-01

    The currently existing mobile mapping systems equipped with active 3D sensors allow to acquire the environment with high sampling rates at high vehicle velocities. While providing an effective solution for environment sensing over large scale distances, such acquisition provides only a discrete representation of the geometry. Thus, a continuous map of the underlying surface must be built. Mobile acquisition introduces several constraints for the state-of-the-art surface reconstruction algorithms. Smoothing becomes a difficult task for recovering sharp depth features while avoiding mesh shrinkage. In addition, interpolation-based techniques are not suitable for noisy datasets acquired by Mobile Laser Scanning (MLS) systems. Furthermore, scalability is a major concern for enabling real-time rendering over large scale distances while preserving geometric details. This paper presents a fully automatic ground surface reconstruction framework capable to deal with the aforementioned constraints. The proposed method exploits the quasi-flat geometry of the ground throughout a morphological segmentation algorithm. Then, a planar Delaunay triangulation is applied in order to reconstruct the ground surface. A smoothing procedure eliminates high frequency peaks, while preserving geometric details in order to provide a regular ground surface. Finally, a decimation step is applied in order to cope with scalability constraints over large scale distances. Experimental results on real data acquired in large urban environments are presented and a performance evaluation with respect to ground truth measurements demonstrate the effectiveness of our method.

  7. A topology control algorithm for preserving minimum-energy paths in wireless ad hoc networks

    Institute of Scientific and Technical Information of China (English)

    SHEN Zhong; CHANG Yilin; CUI Can; ZHANG Xin

    2007-01-01

    In this Paper,a distributed topology control algorithm is proposed.By adjusting the transmission power of each node,this algorithm constructs a wireless network topology with minimum-energy property,i.e.,it preserves a minimum-energy path between every pair of nodes.Moreover,the proposed algorithm can be used in both homogenous and heterogeneous wireless networks.and it can also work without an explicit propagation channel model or the position information of nodes.Simulation results show that the proposed algorithm has advantages over the topology control algorithm based on direct-transmission region in terms of average node degree and power efficiency.

  8. A Fully Developed Flow Thermofluid Model for Topology Optimization of 3D-Printed Air-Cooled Heat Exchangers

    DEFF Research Database (Denmark)

    Haertel, Jan Hendrik Klaas; Nellis, Gregory F.

    2017-01-01

    . The conductance of the heat exchanger is maximized for a prescribed pressure drop and prescribed air-side temperature change across the heat exchanger. Polymer with infilled thermally conducting metal filaments is considered as the heat exchanger material which allows cost effective additive manufacturing...... optimized slot channel model in order to demonstrate the superior performance of the topology optimized designs. Thus, this work demonstrates the usefulness of topology optimization to fully exploit the design freedom afforded by additive manufacturing technologies....

  9. A Minimum-energy Path-preserving Topology Control Algorithm for Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    Jin-Zhao Lin; Xian Zhou; Yun Li

    2009-01-01

    The topology control strategies of wireless sensor networks are very important for reducing the energy consumption of sensor nodes and prolonging the life-span of networks. In this paper, we put forward a minimum-energy path-preserving topology control (MPTC) algorithm based on a concept of none k-redundant edges. MPTC not only resolves the problem of excessive energy consumption because of the unclosed region in small minimum-energy communication network (SMECN), but also preserves at least one minimum-energy path between every pair of nodes in a wireless sensor network. We also propose an energy-efficient reconfiguration protocol that maintains the minimum-energy path property in the case where the network topology changes dynamically. Finally, we demonstrate the performance improvements of our algorithm through simulation.

  10. Insertion of 3-D-primitives in mesh-based representations: towards compact models preserving the details.

    Science.gov (United States)

    Lafarge, Florent; Keriven, Renaud; Brédif, Mathieu

    2010-07-01

    We propose an original hybrid modeling process of urban scenes that represents 3-D models as a combination of mesh-based surfaces and geometric 3-D-primitives. Meshes describe details such as ornaments and statues, whereas 3-D-primitives code for regular shapes such as walls and columns. Starting from an 3-D-surface obtained by multiview stereo techniques, these primitives are inserted into the surface after being detected. This strategy allows the introduction of semantic knowledge, the simplification of the modeling, and even correction of errors generated by the acquisition process. We design a hierarchical approach exploring different scales of an observed scene. Each level consists first in segmenting the surface using a multilabel energy model optimized by -expansion and then in fitting 3-D-primitives such as planes, cylinders or tori on the obtained partition where relevant. Experiments on real meshes, depth maps and synthetic surfaces show good potential for the proposed approach.

  11. Formation of Dirac point and the topological surface states inside the strained gap for mixed 3D Hg1-xCdx Te

    Science.gov (United States)

    Marchewka, Michał

    2016-10-01

    In this paper the results of the numerical calculation obtained for the three-dimensional (3D) strained Hg1-xCdx Te layers for the x-Cd composition from 0.1 to 0.155 and a different mismatch of the lattice constant are presented. For the investigated region of the Cd composition (x value) the negative energy gap (Eg =Γ8 -Γ6) in the Hg1-xCdx Te is smaller than in the case of pure HgTe which, as it turns out, has a significant influence on the topological surface states (TSS) and the position of the Dirac point. The numerical calculation based on the finite difference method applied for the 8×8 kp model with the in-plane tensile strain for (001) growth oriented structure shows that the Dirac cone inside the induced insulating band gap for non zero of the Cd composition and a bigger strain caused by the bigger lattice mismatch (than for the 3D HgTe TI) can be obtained. It was also shown how different x-Cd compounds move the Dirac cone from the valence band into the band gap. The presented results show that 75 nm wide 3D Hg1-xCdx Te structures with x ≈ 0.155 and 1.6% lattice mismatch make the system a true topological insulator with the dispersion of the topological surface states similar to those ones obtained for the strained CdTe/HgTe QW.

  12. Pressure evolution of electrical transport in the 3D topological insulator (Bi,Sb)2(Te,Se)3

    Science.gov (United States)

    Jeffries, Jason; Butch, N. P.; Vohra, Y. K.; Weir, S. T.

    2014-03-01

    The group V-VI compounds--like Bi2Se3, Sb2Te3, or Bi2Te3--have been widely studied in recent years for their bulk topological properties. The high-Z members of this series form with the same crystal structure, and are therefore amenable to isostructural substitution studies. It is possible to tune the Bi-Sb and Te-Se ratios such that the material exhibits insulating behavior, thus providing an excellent platform for understanding how a topological insulator evolves with applied pressure. We report our observations of the pressure-dependent electrical transport and compare that behavior with other binary V-VI compounds under pressure. Lawrence Livermore National Laboratory is operated by Lawrence Livermore National Security, LLC, for the U.S. Department of Energy, National Nuclear Security Administration under Contract DE-AC52-07NA27344.

  13. Simultaneous Topology and Size Optimization of 2D and 3D Trusses Using Evolutionary Structural Optimization with regard to Commonly Used Topologies

    Directory of Open Access Journals (Sweden)

    Pavel Tomšič

    2014-07-01

    Full Text Available One of many optimization techniques is the evolutionary structural optimization (ESO, based on the idea that an optimal structure can be achieved by gradually removing ineffectively used materials from the design domain. Production of a multistage optimization is often proposed to reach the best overall solution. In the first stage, the structure is optimized according to a topology criterion, and, in the second stage, sizing optimization is carried out. The efficiency of such an approach is questionable as a fixed topology, for the second stage optimization may not be the most favorable before sizing optimization is carried out. In this paper, the simultaneous topology and size optimization of trusses using the ESO algorithm are discussed. A number of numerical examples are presented to research capacity to achieve optimal solutions for a structural problem. The topology design of the initial design domain is based on commonly used designs for multistorey trusses constructed from straight members. Therefore, the cases are of a slender shape and made from a combination of presented internal designs. The case studies will present an evaluation to show whether the described optimization approach can be beneficial in structural design for the purpose of steel framework designs.

  14. Synthesis, structure and magnetic properties of a 3D Mn(II)-organic framework with ABW-zeolite topology

    Science.gov (United States)

    Yan, Xiao-Zhi; Qin, Lan; Yu, Lei; Han, Lei

    2013-11-01

    A novel three-dimensional metal-organic framework, [Mn(pydc)(DMF)]n (1) (pydc = pyridine-3,4-dicarboxylate, DMF = N,N-dimethylformamide), has been hydrothermally synthesized and structurally characterized, which consists of one-dimension Mn(COO)2 chains and rhombic channels. The porous complex 1 displays a 4-connected ABW-zeolite topology with vertex symbols of 4.6.4.6.6.82, and exhibits high thermal stability (315 °C) and anti-ferromagnetic properties.

  15. A Feature-adaptive Subdivision Method for Real-time 3D Reconstruction of Repeated Topology Surfaces

    Science.gov (United States)

    Lin, Jinhua; Wang, Yanjie; Sun, Honghai

    2017-03-01

    It's well known that rendering for a large number of triangles with GPU hardware tessellation has made great progress. However, due to the fixed nature of GPU pipeline, many off-line methods that perform well can not meet the on-line requirements. In this paper, an optimized Feature-adaptive subdivision method is proposed, which is more suitable for reconstructing surfaces with repeated cusps or creases. An Octree primitive is established in irregular regions where there are the same sharp vertices or creases, this method can find the neighbor geometry information quickly. Because of having the same topology structure between Octree primitive and feature region, the Octree feature points can match the arbitrary vertices in feature region more precisely. In the meanwhile, the patches is re-encoded in the Octree primitive by using the breadth-first strategy, resulting in a meta-table which allows for real-time reconstruction by GPU hardware tessellation unit. There is only one feature region needed to be calculated under Octree primitive, other regions with the same repeated feature generate their own meta-table directly, the reconstruction time is saved greatly for this step. With regard to the meshes having a large number of repeated topology feature, our algorithm improves the subdivision time by 17.575% and increases the average frame drawing time by 0.2373 ms compared to the traditional FAS (Feature-adaptive Subdivision), at the same time the model can be reconstructed in a watertight manner.

  16. Pressure evolution of electrical transport in the 3D topological insulator (Bi,Sb)2(Se,Te)3

    Science.gov (United States)

    Jeffries, J. R.; Butch, N. P.; Vohra, Y. K.; Weir, S. T.

    2015-03-01

    The group V-VI compounds—like Bi2Se3, Sb2Te3, or Bi2Te3—have been widely studied in recent years for their bulk topological properties. The high-Z members of this series form with the same crystal structure, and are therefore amenable to isostructural substitution studies. It is possible to tune the Bi-Sb and Te-Se ratios such that the material exhibits insulating behavior, thus providing an excellent platform for understanding how a topological insulator evolves with applied pressure. We report our observations of the pressure-dependent electrical transport and crystal structure of a pseudobinary (Bi,Sb)2(Te,Se)3 compound. Similar to some of its sister compounds, the (Bi,Sb)2(Te,Se)3 pseudobinary compound undergoes multiple, pressure-induced phase transformations that result in metallization, the onset of a close-packed crystal structure, and the development of distinct superconducting phases.

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

    Science.gov (United States)

    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

  18. Magnification of label maps with a topology-preserving level-set method.

    Science.gov (United States)

    Trede, Dennis; Alexandrov, Theodore; Sagiv, Chen; Maass, Peter

    2012-09-01

    Image segmentation aims at partitioning an image into multiple segments. The application of this procedure produces a label map (also referred to as segmentation map) that classifies the pixels of the original image. In contrast to "natural" images, label maps are nominal-scale images, typically represented as integer-valued images. Nominal-scaled label maps can also appear as a representation of the raw data in areas, such as in geostatistics. In some applications, the original resolution of a label map does not suffice and a larger size map has to be generated. In this paper, we present a magnification algorithm for label maps and nominal images. The main property of our method is that it preserves the topology during the magnification process, which means that no isolated pixel vanishes. To the best of our knowledge, apart from nearest-neighbor interpolation, the problem of label map magnification has not previously been addressed in the literature. The main idea of the proposed method is to accomplish a boundary refinement by smoothing the regions' boundaries on a finer grid. The method relies on well known methods, namely, the fundamental operations of morphological image processing-erosion and dilation-and the level-set method. The level-set method is well suited for our purposes since it does not depend on a parametrization and it is numerically stable. The topological flexibility of the level-set method-often found to be an advantage in applications-is a drawback here, since the topology of the original label map should be preserved. However, using the so-called simple point criterion from digital topology, one can adapt the conventional level-set method so that the topology will not be modified throughout the magnification procedure.

  19. A nano-microstructured artificial-hair-cell-type sensor based on topologically graded 3D carbon nanotube bundles

    Science.gov (United States)

    Yilmazoglu, O.; Yadav, S.; Cicek, D.; Schneider, J. J.

    2016-09-01

    A design for a unique artificial-hair-cell-type sensor (AHCTS) based entirely on 3D-structured, vertically aligned carbon nanotube (CNT) bundles is introduced. Standard microfabrication techniques were used for the straightforward micro-nano integration of vertically aligned carbon nanotube arrays composed of low-layer multi-walled CNTs (two to six layers). The mechanical properties of the carbon nanotube bundles were intensively characterized with regard to various substrates and CNT morphology, e.g. bundle height. The CNT bundles display excellent flexibility and mechanical stability for lateral bending, showing high tear resistance. The integrated 3D CNT sensor can detect three-dimensional forces using the deflection or compression of a central CNT bundle which changes the contact resistance to the shorter neighboring bundles. The complete sensor system can be fabricated using a single chemical vapor deposition (CVD) process step. Moreover, sophisticated external contacts to the surroundings are not necessary for signal detection. No additional sensors or external bias for signal detection are required. This simplifies the miniaturization and the integration of these nanostructures for future microsystem set-ups. The new nanostructured sensor system exhibits an average sensitivity of 2100 ppm in the linear regime with the relative resistance change per micron (ppm μm-1) of the individual CNT bundle tip deflection. Furthermore, experiments have shown highly sensitive piezoresistive behavior with an electrical resistance decrease of up to ˜11% at 50 μm mechanical deflection. The detection sensitivity is as low as 1 μm of deflection, and thus highly comparable with the tactile hair sensors of insects, having typical thresholds on the order of 30-50 μm. The AHCTS can easily be adapted and applied as a flow, tactile or acceleration sensor as well as a vibration sensor. Potential applications of the latter might come up in artificial cochlear systems. In

  20. A nano-microstructured artificial-hair-cell-type sensor based on topologically graded 3D carbon nanotube bundles.

    Science.gov (United States)

    Yilmazoglu, O; Yadav, S; Cicek, D; Schneider, J J

    2016-09-09

    A design for a unique artificial-hair-cell-type sensor (AHCTS) based entirely on 3D-structured, vertically aligned carbon nanotube (CNT) bundles is introduced. Standard microfabrication techniques were used for the straightforward micro-nano integration of vertically aligned carbon nanotube arrays composed of low-layer multi-walled CNTs (two to six layers). The mechanical properties of the carbon nanotube bundles were intensively characterized with regard to various substrates and CNT morphology, e.g. bundle height. The CNT bundles display excellent flexibility and mechanical stability for lateral bending, showing high tear resistance. The integrated 3D CNT sensor can detect three-dimensional forces using the deflection or compression of a central CNT bundle which changes the contact resistance to the shorter neighboring bundles. The complete sensor system can be fabricated using a single chemical vapor deposition (CVD) process step. Moreover, sophisticated external contacts to the surroundings are not necessary for signal detection. No additional sensors or external bias for signal detection are required. This simplifies the miniaturization and the integration of these nanostructures for future microsystem set-ups. The new nanostructured sensor system exhibits an average sensitivity of 2100 ppm in the linear regime with the relative resistance change per micron (ppm μm(-1)) of the individual CNT bundle tip deflection. Furthermore, experiments have shown highly sensitive piezoresistive behavior with an electrical resistance decrease of up to ∼11% at 50 μm mechanical deflection. The detection sensitivity is as low as 1 μm of deflection, and thus highly comparable with the tactile hair sensors of insects, having typical thresholds on the order of 30-50 μm. The AHCTS can easily be adapted and applied as a flow, tactile or acceleration sensor as well as a vibration sensor. Potential applications of the latter might come up in artificial cochlear systems. In

  1. Centenary of the Battle of Vimy (france, 1917): Preserving the Memory of the Great War Through 3d Recording of the Maison Blanche Souterraine

    Science.gov (United States)

    Murtiyoso, A.; Grussenmeyer, P.; Guillemin, S.; Prilaux, G.

    2017-08-01

    The Battle of Vimy Ridge was a military engagement between the Canadian Corps and the German Empire during the Great War (1914-1918). In this battle, Canadian troops fought as a single unit and won the day. It marked an important point in Canadian history as a nation. The year 2017 marks the centenary of this battle. In commemoration of this event, the Pas-de-Calais Departmental Council financed a 3D recording mission for one of the underground tunnels (souterraines) used as refuge by the Canadian soldiers several weeks prior to the battle. A combination of Terrestrial Laser Scanner (TLS) and close-range photogrammetry techniques was employed in order to document not only the souterraine, but also the various carvings and graffitis created by the soldiers on its walls. The resulting point clouds were registered to the French national geodetic system, and then meshed and textured in order to create a precise 3D model of the souterraine. In this paper, the workflow taken during the project as well as several results will be discussed. In the end, the resulting 3D model was used to create derivative products such as maps, section profiles, and also virtual visit videos. The latter helps the dissemination of the 3D information and thus aids in the preservation of the memory of the Great War for Canada.

  2. 三维模型近刚性保体变形%3D Model Quasi-rigid Deformation with Volume Preservation

    Institute of Scientific and Technical Information of China (English)

    刘炯宙; 李基拓; 陆国栋

    2013-01-01

    为保持三维模型表面细节和模型体积,提高模型变形的真实感效果,提出一种基于能量最小化的近刚性保体变形方法.首先对模型进行Laplacian变形,在此基础上,通过极分解求解曲面局部区域三角形的旋转变形,构建模型刚性变形能;然后通过模型体积积分离散化将模型体积变形约束转化为模型曲面变形约束,构建体积变形能;再通过衡量约束点的位置变形误差构建约束变形能.在最小二乘意义下最小化上述加权变形能,获得模型变形结果.实例结果表明,文中方法能够在线性的算法效率下获得近刚性保体变形效果,为模型的真实感变形提供了一条有效的途径.%Surface detail preservation and model volume preservation are two important aspects for 3D model realistic deformation. A large number of methods for preserving both of the above two aspects have been developed in the past few years. However neither sole detail preserved method nor sole volume preserved method can well preserve them. In this paper, a 3D quasi-rigid deformation integrated with volume preservation approach is proposed. Model deformation is achieved by iteratively minimizing a combined deformation energy: the surface rigidity energy measures the deviation degree of the local surface deformation from its ideal rigid deformation and is computed by polar decomposing the Laplacian surface deformation result; the volume deformation energy measures the volume changing during deformation and is expressed through discretizing the model surface volumetric integration; the constraint energy measures how well the customer's interactive constraints being met. Experimental results show that our approach can obtain quasi-rigid and volume-preserved model deformation results within linear algorithm complexity.

  3. Exceptionally preserved Cambrian trilobite digestive system revealed in 3D by synchrotron-radiation X-ray tomographic microscopy.

    Directory of Open Access Journals (Sweden)

    Mats E Eriksson

    Full Text Available The Cambrian 'Orsten' fauna comprises exceptionally preserved and phosphatised microscopic arthropods. The external morphology of these fossils is well known, but their internal soft-tissue anatomy has remained virtually unknown. Here, we report the first non-biomineralised tissues from a juvenile polymerid trilobite, represented by digestive structures, glands, and connective strands harboured in a hypostome from the Swedish 'Orsten' fauna. Synchrotron-radiation X-ray tomographic microscopy enabled three-dimensional internal recordings at sub-micrometre resolution. The specimen provides the first unambiguous evidence for a J-shaped anterior gut and the presence of a crop with a constricted alimentary tract in the Trilobita. Moreover, the gut is Y-shaped in cross section, probably due to a collapsed lumen of that shape, another feature which has not previously been observed in trilobites. The combination of anatomical features suggests that the trilobite hypostome is functionally analogous to the labrum of euarthropods and that it was a sophisticated element closely integrated with the digestive system. This study also briefly addresses the preservational bias of the 'Orsten' fauna, particularly the near-absence of polymerid trilobites, and the taphonomy of the soft-tissue-harbouring hypostome.

  4. Topological duality between vortices and planar Skyrmions in BPS theories with area-preserving diffeomorphism symmetries

    Science.gov (United States)

    Adam, C.; Sanchez-Guillen, J.; Wereszczynski, A.; Zakrzewski, W. J.

    2013-01-01

    The Bogomol’nyi-Prasad-Sommerfield (BPS) baby Skyrme models are submodels of baby Skyrme models, where the nonlinear sigma model term is suppressed. They have Skyrmion solutions saturating a BPS bound, and the corresponding static energy functional is invariant under area-preserving diffeomorphisms (APDs). Here we show that the solitons in the BPS baby Skyrme model, which carry a nontrivial topological charge Qb∈π2(S2) (a winding number), are dual to vortices in a BPS vortex model with a topological charge Qv∈π1(S1) (a vortex number), in the sense that there is a map between the BPS solutions of the two models. The corresponding energy densities of the BPS solutions of the two models are identical. A further consequence of the duality is that the dual BPS vortex models inherit the BPS property and the infinitely many symmetries (APDs) of the BPS baby Skyrme models. Finally, we demonstrate that the same topological duality continues to hold for the U(1) gauged versions of the models.

  5. Analysis of trabecular bone architectural changes induced by osteoarthritis in rabbit femur using 3D active shape model and digital topology

    Science.gov (United States)

    Saha, P. K.; Rajapakse, C. S.; Williams, D. S.; Duong, L.; Coimbra, A.

    2007-03-01

    Osteoarthritis (OA) is the most common chronic joint disease, which causes the cartilage between the bone joints to wear away, leading to pain and stiffness. Currently, progression of OA is monitored by measuring joint space width using x-ray or cartilage volume using MRI. However, OA affects all periarticular tissues, including cartilage and bone. It has been shown previously that in animal models of OA, trabecular bone (TB) architecture is particularly affected. Furthermore, relative changes in architecture are dependent on the depth of the TB region with respect to the bone surface and main direction of load on the bone. The purpose of this study was to develop a new method for accurately evaluating 3D architectural changes induced by OA in TB. Determining the TB test domain that represents the same anatomic region across different animals is crucial for studying disease etiology, progression and response to therapy. It also represents a major technical challenge in analyzing architectural changes. Here, we solve this problem using a new active shape model (ASM)-based approach. A new and effective semi-automatic landmark selection approach has been developed for rabbit distal femur surface that can easily be adopted for many other anatomical regions. It has been observed that, on average, a trained operator can complete the user interaction part of landmark specification process in less than 15 minutes for each bone data set. Digital topological analysis and fuzzy distance transform derived parameters are used for quantifying TB architecture. The method has been applied on micro-CT data of excised rabbit femur joints from anterior cruciate ligament transected (ACLT) (n = 6) and sham (n = 9) operated groups collected at two and two-to-eight week post-surgery, respectively. An ASM of the rabbit right distal femur has been generated from the sham group micro-CT data. The results suggest that, in conjunction with ASM, digital topological parameters are suitable for

  6. CoRPORATE: cortical reconstruction by pruning outliers with Reeb analysis and topology-preserving evolution.

    Science.gov (United States)

    Shi, Yonggang; Lai, Rongjie; Toga, Arthur W

    2011-01-01

    In this paper we propose a novel system for the accurate reconstruction of cortical surfaces from magnetic resonance images. At the core of our system is a novel framework for outlier detection and pruning by integrating intrinsic Reeb analysis of Laplace-Beltrami eigen-functions with topology-preserving evolution for localized filtering of outliers, which avoids unnecessary smoothing and shrinkage of cortical regions with high curvature. In our experiments, we compare our method with FreeSurfer and illustrate that our results can better capture cortical geometry in deep sulcal regions. To demonstrate the robustness of our method, we apply it to over 1300 scans from the Alzheimer's Disease Neuroimaging Initiative (ADNI). We show that cross-sectional group differences and longitudinal changes can be detected successfully with our method.

  7. Visual Encoding of Dissimilarity Data via Topology-Preserving Map Deformation.

    Science.gov (United States)

    Bouts, Quirijn W; Dwyer, Tim; Dykes, Jason; Speckmann, Bettina; Goodwin, Sarah; Riche, Nathalie Henry; Carpendale, Sheelagh; Liebman, Ariel

    2016-09-01

    We present an efficient technique for topology-preserving map deformation and apply it to the visualization of dissimilarity data in a geographic context. Map deformation techniques such as value-by-area cartograms are well studied. However, using deformation to highlight (dis)similarity between locations on a map in terms of their underlying data attributes is novel. We also identify an alternative way to represent dissimilarities on a map through the use of visual overlays. These overlays are complementary to deformation techniques and enable us to assess the quality of the deformation as well as to explore the design space of blending the two methods. Finally, we demonstrate how these techniques can be useful in several-quite different-applied contexts: travel-time visualization, social demographics research and understanding energy flowing in a wide-area power-grid.

  8. Topology

    CERN Document Server

    Lefschetz, Solomon

    1930-01-01

    Lefschetz's Topology was written in the period in between the beginning of topology, by Poincaré, and the establishment of algebraic topology as a well-formed subject, separate from point-set or geometric topology. At this time, Lefschetz had already proved his first fixed-point theorems. In some sense, the present book is a description of the broad subject of topology into which Lefschetz's theory of fixed points fits. Lefschetz takes the opportunity to describe some of the important applications of his theory, particularly in algebraic geometry, to problems such as counting intersections of

  9. Topology

    CERN Document Server

    Hocking, John G

    1988-01-01

    ""As textbook and reference work, this is a valuable addition to the topological literature."" - Mathematical ReviewsDesigned as a text for a one-year first course in topology, this authoritative volume offers an excellent general treatment of the main ideas of topology. It includes a large number and variety of topics from classical topology as well as newer areas of research activity.There are four set-theoretic chapters, followed by four primarily algebraic chapters. Chapter I covers the fundamentals of topological and metrical spaces, mappings, compactness, product spaces, the Tychonoff t

  10. Topology

    CERN Document Server

    Kuratowski, Kazimierz

    1966-01-01

    Topology, Volume I deals with topology and covers topics ranging from operations in logic and set theory to Cartesian products, mappings, and orderings. Cardinal and ordinal numbers are also discussed, along with topological, metric, and complete spaces. Great use is made of closure algebra. Comprised of three chapters, this volume begins with a discussion on general topological spaces as well as their specialized aspects, including regular, completely regular, and normal spaces. Fundamental notions such as base, subbase, cover, and continuous mapping, are considered, together with operations

  11. Topology

    CERN Document Server

    Kuratowski, Kazimierz

    1968-01-01

    Topology, Volume II deals with topology and covers topics ranging from compact spaces and connected spaces to locally connected spaces, retracts, and neighborhood retracts. Group theory and some cutting problems are also discussed, along with the topology of the plane. Comprised of seven chapters, this volume begins with a discussion on the compactness of a topological space, paying particular attention to Borel, Lebesgue, Riesz, Cantor, and Bolzano-Weierstrass conditions. Semi-continuity and topics in dimension theory are also considered. The reader is then introduced to the connecte

  12. Improving 3D spatial queries search: newfangled technique of space filling curves in 3D city modeling

    DEFF Research Database (Denmark)

    Uznir, U.; Anton, François; Suhaibah, A.

    2013-01-01

    web standards. However, these 3D city models consume much more storage compared to two dimensional (2D) spatial data. They involve extra geometrical and topological information together with semantic data. Without a proper spatial data clustering method and its corresponding spatial data access method......, retrieving portions of and especially searching these 3D city models, will not be done optimally. Even though current developments are based on an open data model allotted by the Open Geospatial Consortium (OGC) called CityGML, its XML-based structure makes it challenging to cluster the 3D urban objects...... modeling will improve data retrieval time by means of optimized 3D adjacency, nearest neighbor information and 3D indexing. The Hilbert mapping, which maps a subinterval of the [0, 1] interval to the corresponding portion of the d-dimensional Hilbert’s curve, preserves the Lebesgue measure and is Lipschitz...

  13. Topology

    CERN Document Server

    Manetti, Marco

    2015-01-01

    This is an introductory textbook on general and algebraic topology, aimed at anyone with a basic knowledge of calculus and linear algebra. It provides full proofs and includes many examples and exercises. The covered topics include: set theory and cardinal arithmetic; axiom of choice and Zorn's lemma; topological spaces and continuous functions; connectedness and compactness; Alexandrov compactification; quotient topologies; countability and separation axioms; prebasis and Alexander's theorem; the Tychonoff theorem and paracompactness; complete metric spaces and function spaces; Baire spaces; homotopy of maps; the fundamental group; the van Kampen theorem; covering spaces; Brouwer and Borsuk's theorems; free groups and free product of groups; and basic category theory. While it is very concrete at the beginning, abstract concepts are gradually introduced. It is suitable for anyone needing a basic, comprehensive introduction to general and algebraic topology and its applications.

  14. Detail-Preserving Bas-relief on Surface from 3D Scene%细节保持的曲面浅浮雕算法

    Institute of Scientific and Technical Information of China (English)

    李博; 刘胜兰; 张丽艳

    2012-01-01

    A novel algorithm for making the bas-relief from 3D shape onto a curved surface is proposed in order to preserve relief details and get smooth relief-background transitions. Firstly, a continuous gradient field is obtained by special treatment on the silhouettes, which are located by Canny operator. Secondly, a flattened shape is achieved by compressing the magnitude of the gradient using a proposed nonlinear function. Subsequently, the details on the original 3D shape are maintained and also enhanced using the bilateral filtering on the gradient domain. Finally, the bas-relief on curved surface is reconstructed from the gradient domain by solving an integral equation. In order to eliminate the steps between relief and background, the background surface is associated to the equation as an optimal condition. The equation is solved accurately in frequency field with no need to set iteration stopping criteria by taking advantages of differential properties of Fourier transformation. The height of bas-relief, the detail sharpness and the transition smoothness can be effectively controlled by tuning the parameters. The experiments demonstrate that the parameters in the algorithm have intuitive geometry meaning, and the obtained bas-relief owns distinct details and smooth relief-background transitions.%为保持曲面浮雕的细节特征,改善浮雕与背景曲面的过渡效果,提出一种细节保持的曲面浮雕算法.首先采用Canny箅子在梯度域定位内外轮廓,获得连续的梯度域;其次提出非线性函数,并用其压缩梯度幅值实现形状压缩;再通过双边滤波算子来保持和增强浮雕细节;最终通过求解积分方程重建曲面浮雕.该算法将背景曲面作为积分方程的优化条件,使浮雕在轮廓处向曲面光滑过渡;在重建过程中利用Fourier变换的微分性质在频域实现方程的精确求解,无需设置迭代收敛条件;通过调整参数可方便地控制浮雕整体变化范围、

  15. Unoriented 3d TFTs

    CERN Document Server

    Bhardwaj, Lakshya

    2016-01-01

    This paper generalizes two facts about oriented 3d TFTs to the unoriented case. On one hand, it is known that oriented 3d TFTs having a topological boundary condition admit a state-sum construction known as the Turaev-Viro construction. This is related to the string-net construction of fermionic phases of matter. We show how Turaev-Viro construction can be generalized to unoriented 3d TFTs. On the other hand, it is known that the "fermionic" versions of oriented TFTs, known as Spin-TFTs, can be constructed in terms of "shadow" TFTs which are ordinary oriented TFTs with an anomalous Z_2 1-form symmetry. We generalize this correspondence to Pin+ TFTs by showing that they can be constructed in terms of ordinary unoriented TFTs with anomalous Z_2 1-form symmetry having a mixed anomaly with time-reversal symmetry. The corresponding Pin+ TFT does not have any anomaly for time-reversal symmetry however and hence it can be unambiguously defined on a non-orientable manifold. In case a Pin+ TFT admits a topological bou...

  16. A new computer program for topological, visual analysis of 3D particle configurations based on visual representation of radial distribution function peaks as bonds

    CERN Document Server

    Metere, Alfredo; Dzugutov, Mikhail

    2015-01-01

    We present a new program able to perform unique visual analysis on generic particle systems: PASYVAT (PArticle SYstem Visual Analysis Tool). More specifically, it can perform a selection of multiple interparticle distance ranges from a radial distribution function (RDF) plot and display them in 3D as bonds. This software can be used with any data set representing a system of particles in 3D. In this manuscript the reader will find a description of the program and its internal structure, with emphasis on its applicability in the study of certain particle configurations, obtained from classical molecular dynamics simulation in condensed matter physics.

  17. Dodecanuclear 3d/4f-metal clusters with a 'Star of David' topology: single-molecule magnetism and magnetocaloric properties.

    Science.gov (United States)

    Alexandropoulos, Dimitris I; Cunha-Silva, Luís; Lorusso, Giulia; Evangelisti, Marco; Tang, Jinkui; Stamatatos, Theocharis C

    2016-01-28

    A family of interwoven molecular inorganic knots, shaped like the 'Star of David', was prepared by the employment of naphthalene-2,3-diol in 3d/4f-metal cluster chemistry; the isoskeletal dodecanuclear compounds exhibit slow relaxation of the magnetization and magnetocaloric properties, depending on the metal ion.

  18. Magnetic properties of bi-, tri- and multicrystals of 3D topological insulator Bi{sub 1−x}–Sb{sub x}(0.06⩽x⩽0.2)

    Energy Technology Data Exchange (ETDEWEB)

    Muntyanu, F.M. [Institute of Electronic Engineering and Industrial Technologies, Academy of Sciences of Moldova, Chisinau 2028 (Moldova, Republic of); International Laboratory of High Magnetic Fields and Low Temperatures, Wroclaw 53421 (Poland); Gilewski, A., E-mail: andrzej.gilewski@ml.pan.wroc.pl [International Laboratory of High Magnetic Fields and Low Temperatures, Wroclaw 53421 (Poland); Nenkov, K. [International Laboratory of High Magnetic Fields and Low Temperatures, Wroclaw 53421 (Poland); Leibniz-Institut fur Festkorper und Werkstofforschung, Dresden 01171 (Germany); Rogacki, K. [International Laboratory of High Magnetic Fields and Low Temperatures, Wroclaw 53421 (Poland); Institute of Low Temperatures and Structural Research, Polish Academy of Sciences, Wroclaw 50950 (Poland); Zaleski, A.J. [Institute of Low Temperatures and Structural Research, Polish Academy of Sciences, Wroclaw 50950 (Poland); Fuks, G. [International Laboratory of High Magnetic Fields and Low Temperatures, Wroclaw 53421 (Poland); Leibniz-Institut fur Festkorper und Werkstofforschung, Dresden 01171 (Germany); Chistol, V. [Technical University of Moldova, Chisinau 2004 (Moldova, Republic of)

    2014-03-01

    The magnetic properties of bi-, tri- and multicrystals of 3D topological insulator Bi{sub 1−x}Sb{sub x}(0.06topological defects, ferromagnetic hysteresis loops and magnetic field expulsion have been observed simultaneously.

  19. Exotic quantum phase transitions of 2+1d Dirac fermions, and connections to 2d and 3d topological insulators

    Science.gov (United States)

    Slagle, Kevin

    2015-03-01

    Using determinant quantum Monte Carlo simulations, we demonstrate that an extended Hubbard model on a bilayer honeycomb lattice has two novel quantum phase transitions, each with connections to symmetry protected topological states. 1) The first is a continuous phase transition between the weakly interacting gapless Dirac fermion phase and a strongly interacting fully gapped and symmetric trivial phase. Because there is no spontaneous symmetry breaking, this transition cannot be described by the standard Gross-Neveu model. We argue that this phase transition is related to the Z16 classification of the topological superconductor 3He-B phase with interactions. 2) The second is a quantum critical point between a quantum spin Hall insulator with spin Sz conservation and the previously mentioned strongly interacting gapped phase. At the critical point the single particle excitations remain gapped, while spin and charge gaps close. We argue that this transition is described by a bosonic O(4) nonlinear sigma model field theory with a topological Θ-term.

  20. Metallic powder-bed based 3D printing of cellular scaffolds for orthopaedic implants: A state-of-the-art review on manufacturing, topological design, mechanical properties and biocompatibility.

    Science.gov (United States)

    Tan, X P; Tan, Y J; Chow, C S L; Tor, S B; Yeong, W Y

    2017-07-01

    Metallic cellular scaffold is one of the best choices for orthopaedic implants as a replacement of human body parts, which could improve life quality and increase longevity for the people needed. Unlike conventional methods of making cellular scaffolds, three-dimensional (3D) printing or additive manufacturing opens up new possibilities to fabricate those customisable intricate designs with highly interconnected pores. In the past decade, metallic powder-bed based 3D printing methods emerged and the techniques are becoming increasingly mature recently, where selective laser melting (SLM) and selective electron beam melting (SEBM) are the two representatives. Due to the advantages of good dimensional accuracy, high build resolution, clean build environment, saving materials, high customisability, etc., SLM and SEBM show huge potential in direct customisable manufacturing of metallic cellular scaffolds for orthopaedic implants. Ti-6Al-4V to date is still considered to be the optimal materials for producing orthopaedic implants due to its best combination of biocompatibility, corrosion resistance and mechanical properties. This paper presents a state-of-the-art overview mainly on manufacturing, topological design, mechanical properties and biocompatibility of cellular Ti-6Al-4V scaffolds via SLM and SEBM methods. Current manufacturing limitations, topological shortcomings, uncertainty of biocompatible test were sufficiently discussed herein. Future perspectives and recommendations were given at the end. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Limited Proteolysis Reveals That Amyloids from the 3D Domain-Swapping Cystatin B Have a Non-Native β-Sheet Topology.

    Science.gov (United States)

    Davis, Peter J; Holmes, David; Waltho, Jonathan P; Staniforth, Rosemary A

    2015-07-31

    3D domain-swapping proteins form multimers by unfolding and then sharing of secondary structure elements, often with native-like interactions. Runaway domain swapping is proposed as a mechanism for folded proteins to form amyloid fibres, with examples including serpins and cystatins. Cystatin C amyloids cause a hereditary form of cerebral amyloid angiopathy whilst cystatin B aggregates are found in cases of Unverricht-Lundborg Syndrome, a progressive form of myoclonic epilepsy. Under conditions that favour fibrillisation, cystatins populate stable 3D domain-swapped dimers both in vitro and in vivo that represent intermediates on route to the formation of fibrils. Previous work on cystatin B amyloid fibrils revealed that the α-helical region of the protein becomes disordered and identified the conservation of a continuous 20-residue elongated β-strand (residues 39-58), the latter being a salient feature of the dimeric 3D domain-swapped structure. Here we apply limited proteolysis to cystatin B amyloid fibrils and show that not only the α-helical N-terminal of the protein (residues 1-35) but also the C-terminal of the protein (residues 80-98) can be removed without disturbing the underlying fibril structure. This observation is incompatible with previous models of cystatin amyloid fibrils where the β-sheet is assumed to retain its native antiparallel arrangement. We conclude that our data favour a more generic, at least partially parallel, arrangement for cystatin β-sheet structure in mature amyloids and propose a model that remains consistent with available data for amyloids from either cystatin B or cystatin C.

  2. Application of the Minkowski functionals in 3D to high-resolution MR images of trabecular bone: prediction of the biomechanical strength by nonlinear topological measures

    Science.gov (United States)

    Boehm, Holger F.; Link, Thomas M.; Monetti, Roberto A.; Mueller, Dirk; Rummeny, Ernst J.; Newitt, David; Majumdar, Sharmila; Raeth, Christoph W.

    2004-05-01

    Multi-dimensional convex objects can be characterized with respect to shape, structure, and the connectivity of their components using a set of morphological descriptors known as the Minkowski functionals. In a 3D Euclidian space, these correspond to volume, surface area, mean integral curvature, and the Euler-Poincaré characteristic. We introduce the Minkowski functionals to medical image processing for the morphological analysis of trabecular bone tissue. In the context of osteoporosis-a metabolic disorder leading to a weakening of bone due to deterioration of micro-architecture-the structure of bone increasingly gains attention in the quantification of bone quality. The trabecular architecture of healthy cancellous bone consists of a complex 3D system of inter-connected mineralised elements whereas in osteoporosis the micro-structure is dominated by gaps and disconnections. At present, the standard parameter for diagnosis and assessment of fracture risk in osteoporosis is the bone mineral density (BMD) - a bulk measure of mineralisation irrespective of structural texture characteristics. With the development of modern imaging modalities (high resolution MRI, micro-CT) with spatial resolutions allowing to depict individual trabeculae bone micro-architecture has successfully been analysed using linear, 2- dimensional structural measures adopted from standard histo-morphometry. The preliminary results of our study demonstrate that due to the complex - i.e. the non-linear - network of trabecular bone structures non-linear measures in 3D are superior to linear ones in predicting mechanical properties of trabecular bone from structural information extracted from high resolution MR image data.

  3. Large power factor and anomalous Hall effect and their correlation with observed linear magneto resistance in Co-doped Bi2Se3 3D topological insulator

    Science.gov (United States)

    Singh, Rahul; Shukla, K. K.; Kumar, A.; Okram, G. S.; Singh, D.; Ganeshan, V.; Lakhani, Archana; Ghosh, A. K.; Chatterjee, Sandip

    2016-09-01

    Magnetoresistance (MR), thermo power, magnetization and Hall effect measurements have been performed on Co-doped Bi2Se3 topological insulators. The undoped sample shows that the maximum MR as a destructive interference due to a π-Berry phase leads to a decrease of MR. As the Co is doped, the linearity in MR is increased. The observed MR of Bi2Se3 can be explained with the classical model. The low temperature MR behavior of Co doped samples cannot be explained with the same model, but can be explained with the quantum linear MR model. Magnetization behavior indicates the establishment of ferromagnetic ordering with Co doping. Hall effect data also supports the establishment of ferromagnetic ordering in Co-doped Bi2Se3 samples by showing the anomalous Hall effect. Furthermore, when spectral weight suppression is insignificant, Bi2Se3 behaves as a dilute magnetic semiconductor. Moreover, the maximum power factor is observed when time reversal symmetry (TRS) is maintained. As the TRS is broken the power factor value is decreased, which indicates that with the rise of Dirac cone above the Fermi level the anomalous Hall effect and linearity in MR increase and the power factor decreases.

  4. Large power factor and anomalous Hall effect and their correlation with observed linear magneto resistance in Co-doped Bi2Se3 3D topological insulator.

    Science.gov (United States)

    Singh, Rahul; Shukla, K K; Kumar, A; Okram, G S; Singh, D; Ganeshan, V; Lakhani, Archana; Ghosh, A K; Chatterjee, Sandip

    2016-09-21

    Magnetoresistance (MR), thermo power, magnetization and Hall effect measurements have been performed on Co-doped Bi2Se3 topological insulators. The undoped sample shows that the maximum MR as a destructive interference due to a π-Berry phase leads to a decrease of MR. As the Co is doped, the linearity in MR is increased. The observed MR of Bi2Se3 can be explained with the classical model. The low temperature MR behavior of Co doped samples cannot be explained with the same model, but can be explained with the quantum linear MR model. Magnetization behavior indicates the establishment of ferromagnetic ordering with Co doping. Hall effect data also supports the establishment of ferromagnetic ordering in Co-doped Bi2Se3 samples by showing the anomalous Hall effect. Furthermore, when spectral weight suppression is insignificant, Bi2Se3 behaves as a dilute magnetic semiconductor. Moreover, the maximum power factor is observed when time reversal symmetry (TRS) is maintained. As the TRS is broken the power factor value is decreased, which indicates that with the rise of Dirac cone above the Fermi level the anomalous Hall effect and linearity in MR increase and the power factor decreases.

  5. Wavelet-based regularization and edge preservation for submillimetre 3D list-mode reconstruction data from a high resolution small animal PET system

    Energy Technology Data Exchange (ETDEWEB)

    Jesus Ochoa Dominguez, Humberto de, E-mail: hochoa@uacj.mx [Departamento de Ingenieria Eectrica y Computacion, Universidad Autonoma de Ciudad Juarez, Avenida del Charro 450 Norte, C.P. 32310 Ciudad Juarez, Chihuahua (Mexico); Ortega Maynez, Leticia; Osiris Vergara Villegas, Osslan; Gordillo Castillo, Nelly; Guadalupe Cruz Sanchez, Vianey; Gutierrez Casas, Efren David [Departamento de Ingenieria Eectrica y Computacion, Universidad Autonoma de Ciudad Juarez, Avenida del Charro 450 Norte, C.P. 32310 Ciudad Juarez, Chihuahua (Mexico)

    2011-10-01

    The data obtained from a PET system tend to be noisy because of the limitations of the current instrumentation and the detector efficiency. This problem is particularly severe in images of small animals as the noise contaminates areas of interest within small organs. Therefore, denoising becomes a challenging task. In this paper, a novel wavelet-based regularization and edge preservation method is proposed to reduce such noise. To demonstrate this method, image reconstruction using a small mouse {sup 18}F NEMA phantom and a {sup 18}F mouse was performed. Investigation on the effects of the image quality was addressed for each reconstruction case. Results show that the proposed method drastically reduces the noise and preserves the image details.

  6. Evaluating network inference methods in terms of their ability to preserve the topology and complexity of genetic networks.

    Science.gov (United States)

    Kiani, Narsis A; Zenil, Hector; Olczak, Jakub; Tegnér, Jesper

    2016-03-01

    Network inference is a rapidly advancing field, with new methods being proposed on a regular basis. Understanding the advantages and limitations of different network inference methods is key to their effective application in different circumstances. The common structural properties shared by diverse networks naturally pose a challenge when it comes to devising accurate inference methods, but surprisingly, there is a paucity of comparison and evaluation methods. Historically, every new methodology has only been tested against gold standard (true values) purpose-designed synthetic and real-world (validated) biological networks. In this paper we aim to assess the impact of taking into consideration aspects of topological and information content in the evaluation of the final accuracy of an inference procedure. Specifically, we will compare the best inference methods, in both graph-theoretic and information-theoretic terms, for preserving topological properties and the original information content of synthetic and biological networks. New methods for performance comparison are introduced by borrowing ideas from gene set enrichment analysis and by applying concepts from algorithmic complexity. Experimental results show that no individual algorithm outperforms all others in all cases, and that the challenging and non-trivial nature of network inference is evident in the struggle of some of the algorithms to turn in a performance that is superior to random guesswork. Therefore special care should be taken to suit the method to the purpose at hand. Finally, we show that evaluations from data generated using different underlying topologies have different signatures that can be used to better choose a network reconstruction method.

  7. A Markov random field approach for topology-preserving registration: application to object-based tomographic image interpolation.

    Science.gov (United States)

    Cordero-Grande, Lucilio; Vegas-Sánchez-Ferrero, Gonzalo; Casaseca-de-la-Higuera, Pablo; Alberola-López, Carlos

    2012-04-01

    This paper proposes a topology-preserving multiresolution elastic registration method based on a discrete Markov random field of deformations and a block-matching procedure. The method is applied to the object-based interpolation of tomographic slices. For that purpose, the fidelity of a given deformation to the data is established by a block-matching strategy based on intensity- and gradient-related features, the smoothness of the transformation is favored by an appropriate prior on the field, and the deformation is guaranteed to maintain the topology by imposing some hard constraints on the local configurations of the field. The resulting deformation is defined as the maximum a posteriori configuration. Additionally, the relative influence of the fidelity and smoothness terms is weighted by the unsupervised estimation of the field parameters. In order to obtain an unbiased interpolation result, the registration is performed both in the forward and backward directions, and the resulting transformations are combined by using the local information content of the deformation. The method is applied to magnetic resonance and computed tomography acquisitions of the brain and the torso. Quantitative comparisons offer an overall improvement in performance with respect to related works in the literature. Additionally, the application of the interpolation method to cardiac magnetic resonance images has shown that the removal of any of the main components of the algorithm results in a decrease in performance which has proven to be statistically significant.

  8. Topologic compression for 3D mesh model based on Face Fixer method%基于边扩张算法和熵编码的3D网格模型的拓扑信息压缩

    Institute of Scientific and Technical Information of China (English)

    许敏; 李钢; 吴石虎; 刘宁

    2011-01-01

    Firstly, three categorizes methods of compressing polygon mesh topologic information without triangulations were summarized in the paper. Then, the Face Fixer algorithm based on edge conquering was studied. Finally, several 3D mesh models were compressed after topologic encoding when using the same order adaptive arithmetic coder and range coder. The experiments results showed that range coder is superior to arithmetic coder in compression ratio and velocity with the increasing model size. Thus, for larger model, the adaptive range coder is preferred to compress.%本文总结了三类不经三角剖分直接编码多边形网格模型拓扑信息的单分辨率压缩法,对其中基于边区域扩张的Face Fixer算法进行了研究,并分别应用同阶自适应区间编码法和算术编码法对三角形网格模型和多边形网格模型进行了压缩.实验结果表明:随着模型数据量的增大,区间编码的压缩率和压缩速度反而高于算术编码,因而对于大数据量的网格模型,更适直采用区间编码来压缩.

  9. TITLE: VISION OF THE RECONSTRUCTION OF DESTRUCTED MONUMENTS OF PALMYRA (3D AS A STEP TO REHABILIATE AND PRESERVE THE WHOLESITE

    Directory of Open Access Journals (Sweden)

    A. Arkawi

    2017-08-01

    Full Text Available Syria is one of the world’s most impressive Cultural Heritages in terms of the number and historical significance of its monuments. Palmyra lies in the heart of Syria, an oasis in the midst of the arid desert.it could be considered as a part of this human heritage. In1980 was registered on the world and national heritage list for its huge historical importance. In addition, it was the focus of many studies and researches in the fields of restoration. Then the disaster happened, many monuments were demolished, temple of Ba’al, temple of Bael-shameen, Arch of triumph and the Castle. Lately the Tetrapylon and the Stag. Every Syrian was hurt, the whole world was hurt. The destruction of the city caused its people to become homeless and Palmyra was no longer the oasis we know. We felt pain, so we wanted to make a move, a step forward, to present a work that expresses our love for Palmyra, we organized Palmyra workshop to provide a vision for the reconstruction and revival of the historic site importance. Visions with using new idea & new technology. Palmyra historical areas are considered a large open museum for heritage through history, which is the reason to treat these area as a historical protection precinct and give a vision, ideas, suggestions to the future of Palmary as a first step to preserve the historical buildings& the archeological park.

  10. 特征保持的视点相关三维矢量场流线简化方法%A view-dependent streamline simplification method for 3 D vector fields based on feature-preservation

    Institute of Scientific and Technical Information of China (English)

    孔龙星; 汤晓安; 李欢

    2014-01-01

    The streamline method is an important method in the visualization of 3D vector fields.A view-dependent streamline simplification method for 3D vector fields based on feature-preservation was proposed to solve the problems of streamline occlusion and visual confusion caused by excessive streamlines,and to ensure the streamlines could present the variation law and important features of vector fields exactly.A streamline set of 3D vector fields was generated by particle tracking and was mapped between view-dependents.A feature-preservation computation of the streamline set was implemented.The streamline set is effectively simplified by computing visual effect metric based on iteration.Experimental results show that the visual effects of the streamlines are enhanced on the basis of valid feature-preservation of vector fields.%为了解决三维矢量场可视化中流线数量过多造成的遮挡与视觉混乱问题,同时保证流线能够准确描述矢量场变化规律与重要特征,提出了一种基于特征保持的视点相关三维矢量场流线简化方法。采用粒子跟踪生成3D矢量场流线集,并进行视点相关映射;对流线集进行特征保持计算;基于流线视觉效果度量对流线集进行迭代简化计算,从而实现流线集的有效简化。实验结果表明,能够有效保持矢量场的物理特征,且具有较好的流线视觉效果。

  11. 3D video

    CERN Document Server

    Lucas, Laurent; Loscos, Céline

    2013-01-01

    While 3D vision has existed for many years, the use of 3D cameras and video-based modeling by the film industry has induced an explosion of interest for 3D acquisition technology, 3D content and 3D displays. As such, 3D video has become one of the new technology trends of this century.The chapters in this book cover a large spectrum of areas connected to 3D video, which are presented both theoretically and technologically, while taking into account both physiological and perceptual aspects. Stepping away from traditional 3D vision, the authors, all currently involved in these areas, provide th

  12. 3D Animation Essentials

    CERN Document Server

    Beane, Andy

    2012-01-01

    The essential fundamentals of 3D animation for aspiring 3D artists 3D is everywhere--video games, movie and television special effects, mobile devices, etc. Many aspiring artists and animators have grown up with 3D and computers, and naturally gravitate to this field as their area of interest. Bringing a blend of studio and classroom experience to offer you thorough coverage of the 3D animation industry, this must-have book shows you what it takes to create compelling and realistic 3D imagery. Serves as the first step to understanding the language of 3D and computer graphics (CG)Covers 3D anim

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

    Science.gov (United States)

    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.

  14. EUROPEANA AND 3D

    Directory of Open Access Journals (Sweden)

    D. Pletinckx

    2012-09-01

    Full Text Available The current 3D hype creates a lot of interest in 3D. People go to 3D movies, but are we ready to use 3D in our homes, in our offices, in our communication? Are we ready to deliver real 3D to a general public and use interactive 3D in a meaningful way to enjoy, learn, communicate? The CARARE project is realising this for the moment in the domain of monuments and archaeology, so that real 3D of archaeological sites and European monuments will be available to the general public by 2012. There are several aspects to this endeavour. First of all is the technical aspect of flawlessly delivering 3D content over all platforms and operating systems, without installing software. We have currently a working solution in PDF, but HTML5 will probably be the future. Secondly, there is still little knowledge on how to create 3D learning objects, 3D tourist information or 3D scholarly communication. We are still in a prototype phase when it comes to integrate 3D objects in physical or virtual museums. Nevertheless, Europeana has a tremendous potential as a multi-facetted virtual museum. Finally, 3D has a large potential to act as a hub of information, linking to related 2D imagery, texts, video, sound. We describe how to create such rich, explorable 3D objects that can be used intuitively by the generic Europeana user and what metadata is needed to support the semantic linking.

  15. Uniform grid upsampling of 3D lidar point cloud data

    Science.gov (United States)

    Gurram, Prudhvi; Hu, Shuowen; Chan, Alex

    2013-03-01

    Airborne laser scanning light detection and ranging (LiDAR) systems are used for remote sensing topology and bathymetry. The most common data collection technique used in LiDAR systems employs a linear mode scanning. The resulting scanning data form a non-uniformly sampled 3D point cloud. To interpret and further process the 3D point cloud data, these raw data are usually converted to digital elevation models (DEMs). In order to obtain DEMs in a uniform and upsampled raster format, the elevation information from the available non-uniform 3D point cloud data are mapped onto the uniform grid points. After the mapping is done, the grid points with missing elevation information are lled by using interpolation techniques. In this paper, partial di erential equations (PDE) based approach is proposed to perform the interpolation and to upsample the 3D point cloud onto a uniform grid. Due to the desirable e ects of using higher order PDEs, smoothness is maintained over homogeneous regions, while sharp edge information in the scene well preserved. The proposed algorithm reduces the draping e ects near the edges of distinctive objects in the scene. Such annoying draping e ects are commonly associated with existing point cloud rendering algorithms. Simulation results are presented in this paper to illustrate the advantages of the proposed algorithm.

  16. Cycle graph analysis for 3D roof structure modelling: Concepts and performance

    Science.gov (United States)

    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.

  17. Cubical Cohomology Ring of 3D Photographs

    CERN Document Server

    Gonzalez-Diaz, Rocio; Medrano, Belen; 10.1002/ima.20271

    2011-01-01

    Cohomology and cohomology ring of three-dimensional (3D) objects are topological invariants that characterize holes and their relations. Cohomology ring has been traditionally computed on simplicial complexes. Nevertheless, cubical complexes deal directly with the voxels in 3D images, no additional triangulation is necessary, facilitating efficient algorithms for the computation of topological invariants in the image context. In this paper, we present formulas to directly compute the cohomology ring of 3D cubical complexes without making use of any additional triangulation. Starting from a cubical complex $Q$ that represents a 3D binary-valued digital picture whose foreground has one connected component, we compute first the cohomological information on the boundary of the object, $\\partial Q$ by an incremental technique; then, using a face reduction algorithm, we compute it on the whole object; finally, applying the mentioned formulas, the cohomology ring is computed from such information.

  18. IZDELAVA TISKALNIKA 3D

    OpenAIRE

    Brdnik, Lovro

    2015-01-01

    Diplomsko delo analizira trenutno stanje 3D tiskalnikov na trgu. Prikazan je razvoj in principi delovanja 3D tiskalnikov. Predstavljeni so tipi 3D tiskalnikov, njihove prednosti in slabosti. Podrobneje je predstavljena zgradba in delovanje koračnih motorjev. Opravljene so meritve koračnih motorjev. Opisana je programska oprema za rokovanje s 3D tiskalniki in komponente, ki jih potrebujemo za izdelavo. Diploma se oklepa vprašanja, ali je izdelava 3D tiskalnika bolj ekonomična kot pa naložba v ...

  19. 3D and Education

    Science.gov (United States)

    Meulien Ohlmann, Odile

    2013-02-01

    Today the industry offers a chain of 3D products. Learning to "read" and to "create in 3D" becomes an issue of education of primary importance. 25 years professional experience in France, the United States and Germany, Odile Meulien set up a personal method of initiation to 3D creation that entails the spatial/temporal experience of the holographic visual. She will present some different tools and techniques used for this learning, their advantages and disadvantages, programs and issues of educational policies, constraints and expectations related to the development of new techniques for 3D imaging. Although the creation of display holograms is very much reduced compared to the creation of the 90ies, the holographic concept is spreading in all scientific, social, and artistic activities of our present time. She will also raise many questions: What means 3D? Is it communication? Is it perception? How the seeing and none seeing is interferes? What else has to be taken in consideration to communicate in 3D? How to handle the non visible relations of moving objects with subjects? Does this transform our model of exchange with others? What kind of interaction this has with our everyday life? Then come more practical questions: How to learn creating 3D visualization, to learn 3D grammar, 3D language, 3D thinking? What for? At what level? In which matter? for whom?

  20. FROM 3D MODEL DATA TO SEMANTICS

    Directory of Open Access Journals (Sweden)

    My Abdellah Kassimi

    2012-01-01

    Full Text Available The semantic-based 3D models retrieval systems have become necessary since the increase of 3D modelsdatabases. In this paper, we propose a new method for the mapping problem between 3D model data andsemantic data involved in semantic based retrieval for 3D models given by polygonal meshes. First, wefocused on extracting invariant descriptors from the 3D models and analyzing them to efficient semanticannotation and to improve the retrieval accuracy. Selected shape descriptors provide a set of termscommonly used to describe visually a set of objects using linguistic terms and are used as semanticconcept to label 3D model. Second, spatial relationship representing directional, topological anddistance relationships are used to derive other high-level semantic features and to avoid the problem ofautomatic 3D model annotation. Based on the resulting semantic annotation and spatial concepts, anontology for 3D model retrieval is constructed and other concepts can be inferred. This ontology is usedto find similar 3D models for a given query model. We adopted the query by semantic example approach,in which the annotation is performed mostly automatically. The proposed method is implemented in our3D search engine (SB3DMR, tested using the Princeton Shape Benchmark Database.

  1. TEHNOLOGIJE 3D TISKALNIKOV

    OpenAIRE

    Kolar, Nataša

    2016-01-01

    Diplomsko delo predstavi razvoj tiskanja skozi čas. Podrobneje so opisani 3D tiskalniki, ki uporabljajo različne tehnologije 3D tiskanja. Predstavljene so različne tehnologije 3D tiskanja, njihova uporaba in narejeni prototipi oz. končni izdelki. Diplomsko delo opiše celoten postopek, od zamisli, priprave podatkov in tiskalnika do izdelave prototipa oz. končnega izdelka.

  2. 6D Interpretation of 3D Gravity

    Science.gov (United States)

    Herfray, Yannick; Krasnov, Kirill; Scarinci, Carlos

    2017-02-01

    We show that 3D gravity, in its pure connection formulation, admits a natural 6D interpretation. The 3D field equations for the connection are equivalent to 6D Hitchin equations for the Chern–Simons 3-form in the total space of the principal bundle over the 3-dimensional base. Turning this construction around one gets an explanation of why the pure connection formulation of 3D gravity exists. More generally, we interpret 3D gravity as the dimensional reduction of the 6D Hitchin theory. To this end, we show that any \\text{SU}(2) invariant closed 3-form in the total space of the principal \\text{SU}(2) bundle can be parametrised by a connection together with a 2-form field on the base. The dimensional reduction of the 6D Hitchin theory then gives rise to 3D gravity coupled to a topological 2-form field.

  3. 6D Interpretation of 3D Gravity

    CERN Document Server

    Herfray, Yannick; Scarinci, Carlos

    2016-01-01

    We show that 3D gravity, in its pure connection formulation, admits a natural 6D interpretation. The 3D field equations for the connection are equivalent to 6D Hitchin equations for the Chern-Simons 3-form in the total space of the principal bundle over the 3-dimensional base. Turning this construction around one gets an explanation of why the pure connection formulation of 3D gravity exists. More generally, we interpret 3D gravity as the dimensional reduction of the 6D Hitchin theory. To this end, we show that any SU(2) invariant closed 3-form in the total space of the principal SU(2) bundle can be parametrised by a connection together with a 2-form field on the base. The dimensional reduction of the 6D Hitchin theory then gives rise to 3D gravity coupled to a topological 2-form field.

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

    Science.gov (United States)

    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.

  5. 3D virtuel udstilling

    DEFF Research Database (Denmark)

    Tournay, Bruno; Rüdiger, Bjarne

    2006-01-01

    3d digital model af Arkitektskolens gård med virtuel udstilling af afgangsprojekter fra afgangen sommer 2006. 10 s.......3d digital model af Arkitektskolens gård med virtuel udstilling af afgangsprojekter fra afgangen sommer 2006. 10 s....

  6. A Hybrid 3D Indoor Space Model

    Science.gov (United States)

    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.

  7. A Hybrid 3D Indoor Space Model

    Directory of Open Access Journals (Sweden)

    A. Jamali

    2016-10-01

    Full Text Available 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.

  8. Blender 3D cookbook

    CERN Document Server

    Valenza, Enrico

    2015-01-01

    This book is aimed at the professionals that already have good 3D CGI experience with commercial packages and have now decided to try the open source Blender and want to experiment with something more complex than the average tutorials on the web. However, it's also aimed at the intermediate Blender users who simply want to go some steps further.It's taken for granted that you already know how to move inside the Blender interface, that you already have 3D modeling knowledge, and also that of basic 3D modeling and rendering concepts, for example, edge-loops, n-gons, or samples. In any case, it'

  9. 3D Digital Modelling

    DEFF Research Database (Denmark)

    Hundebøl, Jesper

    wave of new building information modelling tools demands further investigation, not least because of industry representatives' somewhat coarse parlance: Now the word is spreading -3D digital modelling is nothing less than a revolution, a shift of paradigm, a new alphabet... Research qeustions. Based...... on empirical probes (interviews, observations, written inscriptions) within the Danish construction industry this paper explores the organizational and managerial dynamics of 3D Digital Modelling. The paper intends to - Illustrate how the network of (non-)human actors engaged in the promotion (and arrest) of 3......D Modelling (in Denmark) stabilizes - Examine how 3D Modelling manifests itself in the early design phases of a construction project with a view to discuss the effects hereof for i.a. the management of the building process. Structure. The paper introduces a few, basic methodological concepts...

  10. DELTA 3D PRINTER

    Directory of Open Access Journals (Sweden)

    ȘOVĂILĂ Florin

    2016-07-01

    Full Text Available 3D printing is a very used process in industry, the generic name being “rapid prototyping”. The essential advantage of a 3D printer is that it allows the designers to produce a prototype in a very short time, which is tested and quickly remodeled, considerably reducing the required time to get from the prototype phase to the final product. At the same time, through this technique we can achieve components with very precise forms, complex pieces that, through classical methods, could have been accomplished only in a large amount of time. In this paper, there are presented the stages of a 3D model execution, also the physical achievement after of a Delta 3D printer after the model.

  11. 3D Hilbert Space Filling Curves in 3D City Modeling for Faster Spatial Queries

    DEFF Research Database (Denmark)

    Ujang, Uznir; Antón Castro, Francesc/François; Azri, Suhaibah;

    2014-01-01

    are presented in this paper. The advantages of implementing space-filling curves in 3D city modeling will improve data retrieval time by means of optimized 3D adjacency, nearest neighbor information and 3D indexing. The Hilbert mapping, which maps a sub-interval of the ([0,1]) interval to the corresponding...... method, retrieving portions of and especially searching these 3D city models, will not be done optimally. Even though current developments are based on an open data model allotted by the Open Geospatial Consortium (OGC) called CityGML, its XML-based structure makes it challenging to cluster the 3D urban...... web standards. However, these 3D city models consume much more storage compared to two dimensional (2 D) spatial data. They involve extra geometrical and topological information together with semantic data. Without a proper spatial data clustering method and its corresponding spatial data access...

  12. Professional Papervision3D

    CERN Document Server

    Lively, Michael

    2010-01-01

    Professional Papervision3D describes how Papervision3D works and how real world applications are built, with a clear look at essential topics such as building websites and games, creating virtual tours, and Adobe's Flash 10. Readers learn important techniques through hands-on applications, and build on those skills as the book progresses. The companion website contains all code examples, video step-by-step explanations, and a collada repository.

  13. AE3D

    Energy Technology Data Exchange (ETDEWEB)

    2016-06-20

    AE3D solves for the shear Alfven eigenmodes and eigenfrequencies in a torodal magnetic fusion confinement device. The configuration can be either 2D (e.g. tokamak, reversed field pinch) or 3D (e.g. stellarator, helical reversed field pinch, tokamak with ripple). The equations solved are based on a reduced MHD model and sound wave coupling effects are not currently included.

  14. Urbanisation and 3d Spatial - a Geometric Approach

    Science.gov (United States)

    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.

  15. The Idaho Virtualization Laboratory 3D Pipeline

    Directory of Open Access Journals (Sweden)

    Nicholas A. Holmer

    2014-05-01

    Full Text Available Three dimensional (3D virtualization and visualization is an important component of industry, art, museum curation and cultural heritage, yet the step by step process of 3D virtualization has been little discussed. Here we review the Idaho Virtualization Laboratory’s (IVL process of virtualizing a cultural heritage item (artifact from start to finish. Each step is thoroughly explained and illustrated including how the object and its metadata are digitally preserved and ultimately distributed to the world.

  16. Topological Chaos in a Three-Dimensional Spherical Vortex

    Science.gov (United States)

    Smith, Spencer; Arenson, Joshua; Mitchell, Kevin

    2016-11-01

    Topological techniques have proven to be powerful tools for characterizing the complexity of advection in many 2D fluid flows. However, the path to extending many techniques to three dimensions is filled with roadblocks, which prevent their application to a wider variety of interesting flows. We successfully extend the homotopic lobe dynamics (HLD) technique, previously developed for 2D area-preserving flows, to 3D volume-preserving flows. Specifically, we use intersecting two-dimensional stable and unstable invariant manifolds to construct a symbolic representation of the topological dynamics. This symbolic representation can be used to classify the trajectories of passively advected particles and to compute mixing measures, such as the topological entropy. In this talk, we apply the 3D HLD technique to an explicit numerical example: a time-periodic perturbation of Hill's spherical vortex, modified to break both rotational symmetry and integrability. For this system, the 3D HLD technique is able to detect a distinction between the topologically forced 2D stretching rate of material surfaces and the 1D stretching rate of material curves, illustrating the truly 3D nature of our approach.

  17. Two Accelerating Techniques for 3D Reconstruction

    Institute of Scientific and Technical Information of China (English)

    刘世霞; 胡事民; 孙家广

    2002-01-01

    Automatic reconstruction of 3D objects from 2D orthographic views has been a major research issue in CAD/CAM. In this paper, two accelerating techniques to improve the efficiency of reconstruction are presented. First, some pseudo elements are removed by depth and topology information as soon as the wire-frame is constructed, which reduces the searching space. Second, the proposed algorithm does not establish all possible surfaces in the process of generating 3D faces. The surfaces and edge loops are generated by using the relationship between the boundaries of 3D faces and their projections. This avoids the growth in combinational complexity of previous methods that have to check all possible pairs of 3D candidate edges.

  18. Colloquium: Topological band theory

    Science.gov (United States)

    Bansil, A.; Lin, Hsin; Das, Tanmoy

    2016-04-01

    The first-principles band theory paradigm has been a key player not only in the process of discovering new classes of topologically interesting materials, but also for identifying salient characteristics of topological states, enabling direct and sharpened confrontation between theory and experiment. This review begins by discussing underpinnings of the topological band theory, which involve a layer of analysis and interpretation for assessing topological properties of band structures beyond the standard band theory construct. Methods for evaluating topological invariants are delineated, including crystals without inversion symmetry and interacting systems. The extent to which theoretically predicted properties and protections of topological states have been verified experimentally is discussed, including work on topological crystalline insulators, disorder and interaction driven topological insulators (TIs), topological superconductors, Weyl semimetal phases, and topological phase transitions. Successful strategies for new materials discovery process are outlined. A comprehensive survey of currently predicted 2D and 3D topological materials is provided. This includes binary, ternary, and quaternary compounds, transition metal and f -electron materials, Weyl and 3D Dirac semimetals, complex oxides, organometallics, skutterudites, and antiperovskites. Also included is the emerging area of 2D atomically thin films beyond graphene of various elements and their alloys, functional thin films, multilayer systems, and ultrathin films of 3D TIs, all of which hold exciting promise of wide-ranging applications. This Colloquium concludes by giving a perspective on research directions where further work will broadly benefit the topological materials field.

  19. Reconnection experiments with 3D magnetic nulls

    Science.gov (United States)

    Vrublevskis, A.; Egedal, J.; Le, A.; Montag, P.

    2011-10-01

    Three-dimensional effects have been crucial in explaining experiments at the Versatile Toroidal Facility (VTF) even in nominal axisymmetric plasmas with a non-vanishing toroidal field. In general, depending on the topological and geometric structure of the magnetic field, a rich collection of magnetic reconnection scenarios is possible in three dimensions. The new adjustable set of coils in VTF allows exploring reconnection in 2D and 3D geometries including configurations with magnetic null points. We present results of a numerical and experimental investigation of magnetic field topologies attainable in VTF. This work was supported by NSF CAREER Award 0844620.

  20. 3D modeling of metallic grain growth

    Energy Technology Data Exchange (ETDEWEB)

    George, D.; Carlson, N.; Gammel, J.T.; Kuprat, A.

    1999-06-01

    This paper will describe simulating metallic grain growth using the Gradient Weighted Moving Finite Elements code, GRAIN3D. The authors also describe the set of mesh topology change operations developed to respond to changes in the physical topology such as the collapse of grains and to maintain uniform calculational mesh quality. Validation of the method is demonstrated by comparison to analytic calculations. The authors present results of multigrain simulations where grain boundaries evolve by mean curvature motion and include results which incorporate grain boundary orientation dependence.

  1. 3D Projection Installations

    DEFF Research Database (Denmark)

    Halskov, Kim; Johansen, Stine Liv; Bach Mikkelsen, Michelle

    2014-01-01

    Three-dimensional projection installations are particular kinds of augmented spaces in which a digital 3-D model is projected onto a physical three-dimensional object, thereby fusing the digital content and the physical object. Based on interaction design research and media studies, this article...... contributes to the understanding of the distinctive characteristics of such a new medium, and identifies three strategies for designing 3-D projection installations: establishing space; interplay between the digital and the physical; and transformation of materiality. The principal empirical case, From...... Fingerplan to Loop City, is a 3-D projection installation presenting the history and future of city planning for the Copenhagen area in Denmark. The installation was presented as part of the 12th Architecture Biennale in Venice in 2010....

  2. 3D Spectroscopic Instrumentation

    CERN Document Server

    Bershady, Matthew A

    2009-01-01

    In this Chapter we review the challenges of, and opportunities for, 3D spectroscopy, and how these have lead to new and different approaches to sampling astronomical information. We describe and categorize existing instruments on 4m and 10m telescopes. Our primary focus is on grating-dispersed spectrographs. We discuss how to optimize dispersive elements, such as VPH gratings, to achieve adequate spectral resolution, high throughput, and efficient data packing to maximize spatial sampling for 3D spectroscopy. We review and compare the various coupling methods that make these spectrographs ``3D,'' including fibers, lenslets, slicers, and filtered multi-slits. We also describe Fabry-Perot and spatial-heterodyne interferometers, pointing out their advantages as field-widened systems relative to conventional, grating-dispersed spectrographs. We explore the parameter space all these instruments sample, highlighting regimes open for exploitation. Present instruments provide a foil for future development. We give an...

  3. Radiochromic 3D Detectors

    Science.gov (United States)

    Oldham, Mark

    2015-01-01

    Radiochromic materials exhibit a colour change when exposed to ionising radiation. Radiochromic film has been used for clinical dosimetry for many years and increasingly so recently, as films of higher sensitivities have become available. The two principle advantages of radiochromic dosimetry include greater tissue equivalence (radiologically) and the lack of requirement for development of the colour change. In a radiochromic material, the colour change arises direct from ionising interactions affecting dye molecules, without requiring any latent chemical, optical or thermal development, with important implications for increased accuracy and convenience. It is only relatively recently however, that 3D radiochromic dosimetry has become possible. In this article we review recent developments and the current state-of-the-art of 3D radiochromic dosimetry, and the potential for a more comprehensive solution for the verification of complex radiation therapy treatments, and 3D dose measurement in general.

  4. Interaktiv 3D design

    DEFF Research Database (Denmark)

    Villaume, René Domine; Ørstrup, Finn Rude

    2002-01-01

    Projektet undersøger potentialet for interaktiv 3D design via Internettet. Arkitekt Jørn Utzons projekt til Espansiva blev udviklet som et byggesystem med det mål, at kunne skabe mangfoldige planmuligheder og mangfoldige facade- og rumudformninger. Systemets bygningskomponenter er digitaliseret som...... 3D elementer og gjort tilgængelige. Via Internettet er det nu muligt at sammenstille og afprøve en uendelig  række bygningstyper som  systemet blev tænkt og udviklet til....

  5. Factorization of the 3d superconformal index

    CERN Document Server

    Hwang, Chiung; Park, Jaemo

    2012-01-01

    We prove that 3d superconformal index for general $\\mathcal N=2$ U(N) gauge group with fundamentals and anti-fundmentals with/without Chern-Simons terms is factorized into vortex and anti-vortex partition function. We show that for simple cases, 3d vortex partition function coincides with a suitable topological open string partition function. We provide much more elegant derivation at the index level for $\\mathcal N=2$ Seiberg-like dualities of unitary gauge groups with fundamantal matters and $\\mathcal N=4$ mirror symmetry

  6. 3D Wire 2015

    DEFF Research Database (Denmark)

    Jordi, Moréton; F, Escribano; J. L., Farias

    This document is a general report on the implementation of gamification in 3D Wire 2015 event. As the second gamification experience in this event, we have delved deeply in the previous objectives (attracting public areas less frequented exhibition in previous years and enhance networking) and ha......, improves socialization and networking, improves media impact, improves fun factor and improves encouragement of the production team....

  7. Shaping 3-D boxes

    DEFF Research Database (Denmark)

    Stenholt, Rasmus; Madsen, Claus B.

    2011-01-01

    Enabling users to shape 3-D boxes in immersive virtual environments is a non-trivial problem. In this paper, a new family of techniques for creating rectangular boxes of arbitrary position, orientation, and size is presented and evaluated. These new techniques are based solely on position data...

  8. Tangible 3D Modelling

    DEFF Research Database (Denmark)

    Hejlesen, Aske K.; Ovesen, Nis

    2012-01-01

    This paper presents an experimental approach to teaching 3D modelling techniques in an Industrial Design programme. The approach includes the use of tangible free form models as tools for improving the overall learning. The paper is based on lecturer and student experiences obtained through facil...

  9. 3D photoacoustic imaging

    Science.gov (United States)

    Carson, Jeffrey J. L.; Roumeliotis, Michael; Chaudhary, Govind; Stodilka, Robert Z.; Anastasio, Mark A.

    2010-06-01

    Our group has concentrated on development of a 3D photoacoustic imaging system for biomedical imaging research. The technology employs a sparse parallel detection scheme and specialized reconstruction software to obtain 3D optical images using a single laser pulse. With the technology we have been able to capture 3D movies of translating point targets and rotating line targets. The current limitation of our 3D photoacoustic imaging approach is its inability ability to reconstruct complex objects in the field of view. This is primarily due to the relatively small number of projections used to reconstruct objects. However, in many photoacoustic imaging situations, only a few objects may be present in the field of view and these objects may have very high contrast compared to background. That is, the objects have sparse properties. Therefore, our work had two objectives: (i) to utilize mathematical tools to evaluate 3D photoacoustic imaging performance, and (ii) to test image reconstruction algorithms that prefer sparseness in the reconstructed images. Our approach was to utilize singular value decomposition techniques to study the imaging operator of the system and evaluate the complexity of objects that could potentially be reconstructed. We also compared the performance of two image reconstruction algorithms (algebraic reconstruction and l1-norm techniques) at reconstructing objects of increasing sparseness. We observed that for a 15-element detection scheme, the number of measureable singular vectors representative of the imaging operator was consistent with the demonstrated ability to reconstruct point and line targets in the field of view. We also observed that the l1-norm reconstruction technique, which is known to prefer sparseness in reconstructed images, was superior to the algebraic reconstruction technique. Based on these findings, we concluded (i) that singular value decomposition of the imaging operator provides valuable insight into the capabilities of

  10. 基于庞加莱代数的3D TEN模型及其拓扑关系建立研究%3D TEN data model and its establishment of topological relations based on Poincaré algebra

    Institute of Scientific and Technical Information of China (English)

    刘艳; 武广臣

    2014-01-01

    庞加莱代数描述了3D TEN的基本计算原理,是解决TEN建模和建立拓扑关系的重要基础.根据庞加莱代数的连接和计算原理,本文阐述了3D TEN数据模型的建模准则和拓扑关系建立准则,前者包括TEN数据结构与属性的建立,后者包括自拓扑准则、TEN之间的拓扑准则以及TEN拓扑操作准则,其中TEN之间的拓扑关系建立是构建TEN拓扑关系的核心内容,因为它决定3D GIS的性能与可扩展性.最后,本文对TEN与DBMS的结合及其可视化表达进行了展望.

  11. Limited Feedback for 3D Massive MIMO under 3D-UMa and 3D-UMi Scenarios

    Directory of Open Access Journals (Sweden)

    Zheng Hu

    2015-01-01

    Full Text Available For three-dimensional (3D massive MIMO utilizing the uniform rectangular array (URA in the base station (BS, we propose a limited feedback transmission scheme in which the channel state information (CSI feedback operations for horizontal domain and vertical domain are separate. Compared to the traditional feedback scheme, the scheme can reduce the feedback overhead, code word index search complexity, and storage requirement. Also, based on the zenith of departure angle (ZoD distribution in 3D-Urban Macro Cell (3D-UMa and 3D-Urban Micro Cell (3D-UMi scenarios, we propose the angle quantization codebook for vertical domain, while the codebook of long term evolution-advanced (LTE-Advanced is still adopted in horizontal domain to preserve compatibility with the LTE-Advanced. Based on the angle quantization codebook, the subsampled 3-bit DFT codebook is designed for vertical domain. The system-level simulation results reveal that, to compromise the feedback overhead and system performance, 2-bit codebook for 3D-UMa scenario and 3-bit codebook for 3D-UMi scenario can meet requirements in vertical domain. The feedback period for vertical domain can also be extended appropriately to reduce the feedback overhead.

  12. The topology of geology 1: Topological analysis

    Science.gov (United States)

    Thiele, Samuel T.; Jessell, Mark W.; Lindsay, Mark; Ogarko, Vitaliy; Wellmann, J. Florian; Pakyuz-Charrier, Evren

    2016-10-01

    Topology has been used to characterise and quantify the properties of complex systems in a diverse range of scientific domains. This study explores the concept and applications of topological analysis in geology. We have developed an automatic system for extracting first order 2D topological information from geological maps, and 3D topological information from models built with the Noddy kinematic modelling system, and equivalent analyses should be possible for other implicit modelling systems. A method is presented for describing the spatial and temporal topology of geological models using a set of adjacency relationships that can be expressed as a topology network, thematic adjacency matrix or hive diagram. We define three types of spatial topology (cellular, structural and lithological) that allow us to analyse different aspects of the geology, and then apply them to investigate the geology of the Hamersley Basin, Western Australia.

  13. Networked 3D Virtual Museum System

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Virtual heritage has become increasingly important in the conservation, preservation, and interpretation of our cultural and natural history. Moreover, rapid advances in digital technologies in recent years offer virtual heritage new direction. This paper introduces our approach toward a networked 3D virtual museum system, especially, how to model, manage, present virtual heritages and furthermore how to use computer network for the share of virtual heritage in the networked virtual environment. This paper first addresses a 3D acquisition and processing technique for virtual heritage modeling and shows some illustrative examples. Then, this paper describes a management of virtual heritage assets that are composed by various rich media. This paper introduces our schemes to present the virtual heritages, which include 3D virtual heritage browser system, CAVE system, and immersive VR theater. Finally, this paper presents the new direction of networked 3D virtual museum of which main idea is remote guide of the virtual heritage using the mixed reality technique.

  14. Space-Based Erbium-Doped Fiber Amplifier Transmitters for Coherent, Ranging, 3D-Imaging, Altimetry, Topology, and Carbon Dioxide Lidar and Earth and Planetary Optical Laser Communications

    Science.gov (United States)

    Storm, Mark; Engin, Doruk; Mathason, Brian; Utano, Rich; Gupta, Shantanu

    2016-06-01

    This paper describes Fibertek, Inc.'s progress in developing space-qualified Erbium-doped fiber amplifier (EDFA) transmitters for laser communications and ranging/topology, and CO2 integrated path differential absorption (IPDA) lidar. High peak power (1 kW) and 6 W of average power supporting multiple communications formats has been demonstrated with 17% efficiency in a compact 3 kg package. The unit has been tested to Technology Readiness Level (TRL) 6 standards. A 20 W EDFA suitable for CO2 lidar has been demonstrated with ~14% efficiency (electrical to optical [e-o]) and its performance optimized for 1571 nm operation.

  15. Space-Based Erbium-Doped Fiber Amplifier Transmitters for Coherent, Ranging, 3D-Imaging, Altimetry, Topology, and Carbon Dioxide Lidar and Earth and Planetary Optical Laser Communications

    Directory of Open Access Journals (Sweden)

    Storm Mark

    2016-01-01

    Full Text Available This paper describes Fibertek, Inc.’s progress in developing space-qualified Erbium-doped fiber amplifier (EDFA transmitters for laser communications and ranging/topology, and CO2 integrated path differential absorption (IPDA lidar. High peak power (1 kW and 6 W of average power supporting multiple communications formats has been demonstrated with 17% efficiency in a compact 3 kg package. The unit has been tested to Technology Readiness Level (TRL 6 standards. A 20 W EDFA suitable for CO2 lidar has been demonstrated with ~14% efficiency (electrical to optical [e-o] and its performance optimized for 1571 nm operation.

  16. 3D and beyond

    Science.gov (United States)

    Fung, Y. C.

    1995-05-01

    This conference on physiology and function covers a wide range of subjects, including the vasculature and blood flow, the flow of gas, water, and blood in the lung, the neurological structure and function, the modeling, and the motion and mechanics of organs. Many technologies are discussed. I believe that the list would include a robotic photographer, to hold the optical equipment in a precisely controlled way to obtain the images for the user. Why are 3D images needed? They are to achieve certain objectives through measurements of some objects. For example, in order to improve performance in sports or beauty of a person, we measure the form, dimensions, appearance, and movements.

  17. 3D Surgical Simulation

    Science.gov (United States)

    Cevidanes, Lucia; Tucker, Scott; Styner, Martin; Kim, Hyungmin; Chapuis, Jonas; Reyes, Mauricio; Proffit, William; Turvey, Timothy; Jaskolka, Michael

    2009-01-01

    This paper discusses the development of methods for computer-aided jaw surgery. Computer-aided jaw surgery allows us to incorporate the high level of precision necessary for transferring virtual plans into the operating room. We also present a complete computer-aided surgery (CAS) system developed in close collaboration with surgeons. Surgery planning and simulation include construction of 3D surface models from Cone-beam CT (CBCT), dynamic cephalometry, semi-automatic mirroring, interactive cutting of bone and bony segment repositioning. A virtual setup can be used to manufacture positioning splints for intra-operative guidance. The system provides further intra-operative assistance with the help of a computer display showing jaw positions and 3D positioning guides updated in real-time during the surgical procedure. The CAS system aids in dealing with complex cases with benefits for the patient, with surgical practice, and for orthodontic finishing. Advanced software tools for diagnosis and treatment planning allow preparation of detailed operative plans, osteotomy repositioning, bone reconstructions, surgical resident training and assessing the difficulties of the surgical procedures prior to the surgery. CAS has the potential to make the elaboration of the surgical plan a more flexible process, increase the level of detail and accuracy of the plan, yield higher operative precision and control, and enhance documentation of cases. Supported by NIDCR DE017727, and DE018962 PMID:20816308

  18. TOWARDS: 3D INTERNET

    Directory of Open Access Journals (Sweden)

    Ms. Swapnali R. Ghadge

    2013-08-01

    Full Text Available In today’s ever-shifting media landscape, it can be a complex task to find effective ways to reach your desired audience. As traditional media such as television continue to lose audience share, one venue in particular stands out for its ability to attract highly motivated audiences and for its tremendous growth potential the 3D Internet. The concept of '3D Internet' has recently come into the spotlight in the R&D arena, catching the attention of many people, and leading to a lot of discussions. Basically, one can look into this matter from a few different perspectives: visualization and representation of information, and creation and transportation of information, among others. All of them still constitute research challenges, as no products or services are yet available or foreseen for the near future. Nevertheless, one can try to envisage the directions that can be taken towards achieving this goal. People who take part in virtual worlds stay online longer with a heightened level of interest. To take advantage of that interest, diverse businesses and organizations have claimed an early stake in this fast-growing market. They include technology leaders such as IBM, Microsoft, and Cisco, companies such as BMW, Toyota, Circuit City, Coca Cola, and Calvin Klein, and scores of universities, including Harvard, Stanford and Penn State.

  19. A non-rigid point matching method with local topology preservation for accurate bladder dose summation in high dose rate cervical brachytherapy.

    Science.gov (United States)

    Chen, Haibin; Zhong, Zichun; Liao, Yuliang; Pompoš, Arnold; Hrycushko, Brian; Albuquerque, Kevin; Zhen, Xin; Zhou, Linghong; Gu, Xuejun

    2016-02-07

    GEC-ESTRO guidelines for high dose rate cervical brachytherapy advocate the reporting of the D2cc (the minimum dose received by the maximally exposed 2cc volume) to organs at risk. Due to large interfractional organ motion, reporting of accurate cumulative D2cc over a multifractional course is a non-trivial task requiring deformable image registration and deformable dose summation. To efficiently and accurately describe the point-to-point correspondence of the bladder wall over all treatment fractions while preserving local topologies, we propose a novel graphic processing unit (GPU)-based non-rigid point matching algorithm. This is achieved by introducing local anatomic information into the iterative update of correspondence matrix computation in the 'thin plate splines-robust point matching' (TPS-RPM) scheme. The performance of the GPU-based TPS-RPM with local topology preservation algorithm (TPS-RPM-LTP) was evaluated using four numerically simulated synthetic bladders having known deformations, a custom-made porcine bladder phantom embedded with twenty one fiducial markers, and 29 fractional computed tomography (CT) images from seven cervical cancer patients. Results show that TPS-RPM-LTP achieved excellent geometric accuracy with landmark residual distance error (RDE) of 0.7  ±  0.3 mm for the numerical synthetic data with different scales of bladder deformation and structure complexity, and 3.7  ±  1.8 mm and 1.6  ±  0.8 mm for the porcine bladder phantom with large and small deformation, respectively. The RDE accuracy of the urethral orifice landmarks in patient bladders was 3.7  ±  2.1 mm. When compared to the original TPS-RPM, the TPS-RPM-LTP improved landmark matching by reducing landmark RDE by 50  ±  19%, 37  ±  11% and 28  ±  11% for the synthetic, porcine phantom and the patient bladders, respectively. This was achieved with a computational time of less than 15 s in all cases

  20. A Novel Energy Efficient Topology Control Scheme Based on a Coverage-Preserving and Sleep Scheduling Model for Sensor Networks.

    Science.gov (United States)

    Shi, Binbin; Wei, Wei; Wang, Yihuai; Shu, Wanneng

    2016-10-14

    In high-density sensor networks, scheduling some sensor nodes to be in the sleep mode while other sensor nodes remain active for monitoring or forwarding packets is an effective control scheme to conserve energy. In this paper, a Coverage-Preserving Control Scheduling Scheme (CPCSS) based on a cloud model and redundancy degree in sensor networks is proposed. Firstly, the normal cloud model is adopted for calculating the similarity degree between the sensor nodes in terms of their historical data, and then all nodes in each grid of the target area can be classified into several categories. Secondly, the redundancy degree of a node is calculated according to its sensing area being covered by the neighboring sensors. Finally, a centralized approximation algorithm based on the partition of the target area is designed to obtain the approximate minimum set of nodes, which can retain the sufficient coverage of the target region and ensure the connectivity of the network at the same time. The simulation results show that the proposed CPCSS can balance the energy consumption and optimize the coverage performance of the sensor network.

  1. Whole-brain structural topology in adult attention-deficit/hyperactivity disorder: Preserved global – disturbed local network organization

    Directory of Open Access Journals (Sweden)

    Justina Sidlauskaite

    2015-01-01

    Full Text Available Prior studies demonstrate altered organization of functional brain networks in attention-deficit/hyperactivity disorder (ADHD. However, the structural underpinnings of these functional disturbances are poorly understood. In the current study, we applied a graph-theoretic approach to whole-brain diffusion magnetic resonance imaging data to investigate the organization of structural brain networks in adults with ADHD and unaffected controls using deterministic fiber tractography. Groups did not differ in terms of global network metrics — small-worldness, global efficiency and clustering coefficient. However, there were widespread ADHD-related effects at the nodal level in relation to local efficiency and clustering. The affected nodes included superior occipital, supramarginal, superior temporal, inferior parietal, angular and inferior frontal gyri, as well as putamen, thalamus and posterior cerebellum. Lower local efficiency of left superior temporal and supramarginal gyri was associated with higher ADHD symptom scores. Also greater local clustering of right putamen and lower local clustering of left supramarginal gyrus correlated with ADHD symptom severity. Overall, the findings indicate preserved global but altered local network organization in adult ADHD implicating regions underpinning putative ADHD-related neuropsychological deficits.

  2. The dimension added by 3D scanning and 3D printing of meteorites

    Science.gov (United States)

    de Vet, S. J.

    2016-01-01

    An overview for the 3D photodocumentation of meteorites is presented, focussing on two 3D scanning methods in relation to 3D printing. The 3D photodocumention of meteorites provides new ways for the digital preservation of culturally, historically or scientifically unique meteorites. It has the potential for becoming a new documentation standard of meteorites that can exist complementary to traditional photographic documentation. Notable applications include (i.) use of physical properties in dark flight-, strewn field-, or aerodynamic modelling; (ii.) collection research of meteorites curated by different museum collections, and (iii.) public dissemination of meteorite models as a resource for educational users. The possible applications provided by the additional dimension of 3D illustrate the benefits for the meteoritics community.

  3. Several Strategies on 3D Modeling of Manmade Objects

    Institute of Scientific and Technical Information of China (English)

    SHAO Zhenfeng; LI Deren; CHENG Qimin

    2004-01-01

    Several different strategies of 3D modeling are adopted for different kinds of manmade objects. Firstly, for those manmade objects with regular structure, if 2D information is available and elevation information can be obtained conveniently, then 3D modeling of them can be executed directly. Secondly, for those manmade objects with complicated structure comparatively and related stereo images pair can be acquired, in the light of topology-based 3D model we finish 3D modeling of them by integrating automatic and semi-automatic object extraction. Thirdly, for the most complicated objects whose geometrical information cannot be got from stereo images pair completely, we turn to topological 3D model based on CAD.

  4. 3D-kompositointi

    OpenAIRE

    Piirainen, Jere

    2015-01-01

    Opinnäytetyössä käydään läpi yleisimpiä 3D-kompositointiin liittyviä tekniikoita sekä kompositointiin käytettyjä ohjelmia ja liitännäisiä. Työssä esitellään myös kompositoinnin juuret 1800-luvun lopulta aina nykyaikaiseen digitaaliseen kompositointiin asti. Kompositointi on yksinkertaisimmillaan usean kuvan liittämistä saumattomasti yhdeksi uskottavaksi kokonaisuudeksi. Vaikka prosessi vaatii visuaalista silmää, vaatii se myös paljon teknistä osaamista. Tämän lisäksi perusymmärrys kamera...

  5. Shaping 3-D boxes

    DEFF Research Database (Denmark)

    Stenholt, Rasmus; Madsen, Claus B.

    2011-01-01

    Enabling users to shape 3-D boxes in immersive virtual environments is a non-trivial problem. In this paper, a new family of techniques for creating rectangular boxes of arbitrary position, orientation, and size is presented and evaluated. These new techniques are based solely on position data......, making them different from typical, existing box shaping techniques. The basis of the proposed techniques is a new algorithm for constructing a full box from just three of its corners. The evaluation of the new techniques compares their precision and completion times in a 9 degree-of-freedom (Do......F) docking experiment against an existing technique, which requires the user to perform the rotation and scaling of the box explicitly. The precision of the users' box construction is evaluated by a novel error metric measuring the difference between two boxes. The results of the experiment strongly indicate...

  6. The 3D-index and normal surfaces

    CERN Document Server

    Garoufalidis, Stavros; Hoffman, Neil; Rubinstein, Hyam

    2016-01-01

    Dimofte, Gaiotto and Gukov introduced a powerful invariant, the 3D-index, associated to a suitable ideal triangulation of a 3-manifold with torus boundary components. The 3D-index is a collection of formal power series in $q^{1/2}$ with integer coefficients. Our goal is to explain how the 3D-index is a generating series of normal surfaces associated to the ideal triangulation. This shows a connection of the 3D-index with classical normal surface theory, and fulfills a dream of constructing topological invariants of 3-manifolds using normal surfaces.

  7. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... create the 3-D effect can confuse or overload the brain, causing some people discomfort even if ... Answers Free Newsletter Get ophthalmologist-reviewed tips and information about eye health and preserving your vision. Privacy ...

  8. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... function in children, nor are there persuasive, conclusive theories on how 3-D digital products could cause ... Answers Free Newsletter Get ophthalmologist-reviewed tips and information about eye health and preserving your vision. Privacy ...

  9. Intraoral 3D scanner

    Science.gov (United States)

    Kühmstedt, Peter; Bräuer-Burchardt, Christian; Munkelt, Christoph; Heinze, Matthias; Palme, Martin; Schmidt, Ingo; Hintersehr, Josef; Notni, Gunther

    2007-09-01

    Here a new set-up of a 3D-scanning system for CAD/CAM in dental industry is proposed. The system is designed for direct scanning of the dental preparations within the mouth. The measuring process is based on phase correlation technique in combination with fast fringe projection in a stereo arrangement. The novelty in the approach is characterized by the following features: A phase correlation between the phase values of the images of two cameras is used for the co-ordinate calculation. This works contrary to the usage of only phase values (phasogrammetry) or classical triangulation (phase values and camera image co-ordinate values) for the determination of the co-ordinates. The main advantage of the method is that the absolute value of the phase at each point does not directly determine the coordinate. Thus errors in the determination of the co-ordinates are prevented. Furthermore, using the epipolar geometry of the stereo-like arrangement the phase unwrapping problem of fringe analysis can be solved. The endoscope like measurement system contains one projection and two camera channels for illumination and observation of the object, respectively. The new system has a measurement field of nearly 25mm × 15mm. The user can measure two or three teeth at one time. So the system can by used for scanning of single tooth up to bridges preparations. In the paper the first realization of the intraoral scanner is described.

  10. Martian terrain - 3D

    Science.gov (United States)

    1997-01-01

    This area of terrain near the Sagan Memorial Station was taken on Sol 3 by the Imager for Mars Pathfinder (IMP). 3D glasses are necessary to identify surface detail.The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  11. 3D Printing and 3D Bioprinting in Pediatrics.

    Science.gov (United States)

    Vijayavenkataraman, Sanjairaj; Fuh, Jerry Y H; Lu, Wen Feng

    2017-07-13

    Additive manufacturing, commonly referred to as 3D printing, is a technology that builds three-dimensional structures and components layer by layer. Bioprinting is the use of 3D printing technology to fabricate tissue constructs for regenerative medicine from cell-laden bio-inks. 3D printing and bioprinting have huge potential in revolutionizing the field of tissue engineering and regenerative medicine. This paper reviews the application of 3D printing and bioprinting in the field of pediatrics.

  12. 3D Porphyrin-Based Covalent Organic Frameworks.

    Science.gov (United States)

    Lin, Guiqing; Ding, Huimin; Chen, Rufan; Peng, Zhengkang; Wang, Baoshan; Wang, Cheng

    2017-06-28

    The design and synthesis of three-dimensional covalent organic frameworks (3D COFs) bearing photoelectric units have been considered as a big challenge. Herein, for the first time, we reported the targeted synthesis of two 3D porphyrin-based COFs (3D-Por-COF and 3D-CuPor-COF), starting from tetrahedral (3D-Td) and square (2D-C4) building blocks connected through [4 + 4] imine condensation reactions. On the basis of structural characterizations, 3D-Por-COF and 3D-CuPor-COF are microporous materials with high surface areas, and are proposed to adopt a 2-fold interpenetrated pts topology with Pmc21 space group. Interestingly, both 3D COFs are photosensitive and can be used as heterogeneous catalyst for generating singlet oxygen under photoirradiation. However, 3D-Por-COF shows enhanced photocatalytic activity compared with 3D-CuPor-COF, indicating the properties of 3D porphyrin-based COFs can be tuned by metalation of porphyrin rings. The results reported here will greatly inspire us to design and synthesize 3D COFs bearing other metalloporphyrins for interesting applications (e.g., catalysis) in the future.

  13. 3D printing for dummies

    CERN Document Server

    Hausman, Kalani Kirk

    2014-01-01

    Get started printing out 3D objects quickly and inexpensively! 3D printing is no longer just a figment of your imagination. This remarkable technology is coming to the masses with the growing availability of 3D printers. 3D printers create 3-dimensional layered models and they allow users to create prototypes that use multiple materials and colors.  This friendly-but-straightforward guide examines each type of 3D printing technology available today and gives artists, entrepreneurs, engineers, and hobbyists insight into the amazing things 3D printing has to offer. You'll discover methods for

  14. 3D VIRTUAL RECONSTRUCTION OF ARCHAEOLOGICAL MONUMENTS

    OpenAIRE

    2014-01-01

    3D Virtual Models are the future of the representation of the existing and destroyed architectural heritage. The term reconstruction defines the re-building of a monument to its state at the time of its history chosen for that particular representation. In recent years the evolution of the technology, has contributed significantly in many aspects of the field of cultural heritage preservation and recording. Techniques like digital image processing, digital orthophoto production, terrestrial l...

  15. Reconnection experiments including 3D magnetic nulls

    Science.gov (United States)

    Le, A.; Egedal, J.; Vrublevskis, A.

    2010-11-01

    A rich collection of magnetic reconnection scenarios is possible in three dimensions depending on the topological and geometric structure of the magnetic field [1]. In recent experiments at the Versatile Toroidal Facility (VTF) three-dimensional effects were essential even in nearly axisymmetric plasmas with a non-vanishing toroidal field [2]. To explore reconnection in 3D geometries including magnetic null points, a new adjustable set of coils will be installed in the vacuum chamber of VTF. The range of vacuum magnetic field topologies attainable in VTF will be explored numerically. Plasma reconnection experiments will be run in these configurations, and measurements will be presented if available. [4pt] [1] CE Parnell, et al., (2009) ``Three-Dimensional Magnetic Reconnection, in Magnetic Coupling between the Interior and the Atmosphere of the Sun,'' eds. S.S. Hasan and R.J. Rutten, Springer-Verlag, Heidelberg, Berlin. [0ex] [2] Katz, N. et al., (2010) Phys. Rev. Lett. 104, 255004.

  16. 3D game environments create professional 3D game worlds

    CERN Document Server

    Ahearn, Luke

    2008-01-01

    The ultimate resource to help you create triple-A quality art for a variety of game worlds; 3D Game Environments offers detailed tutorials on creating 3D models, applying 2D art to 3D models, and clear concise advice on issues of efficiency and optimization for a 3D game engine. Using Photoshop and 3ds Max as his primary tools, Luke Ahearn explains how to create realistic textures from photo source and uses a variety of techniques to portray dynamic and believable game worlds.From a modern city to a steamy jungle, learn about the planning and technological considerations for 3D modelin

  17. Vertex-based diffusion for 3-D mesh denoising.

    Science.gov (United States)

    Zhang, Ying; Ben Hamza, A

    2007-04-01

    We present a vertex-based diffusion for 3-D mesh denoising by solving a nonlinear discrete partial differential equation. The core idea behind our proposed technique is to use geometric insight in helping construct an efficient and fast 3-D mesh smoothing strategy to fully preserve the geometric structure of the data. Illustrating experimental results demonstrate a much improved performance of the proposed approach in comparison with existing methods currently used in 3-D mesh smoothing.

  18. 3D Printing an Octohedron

    OpenAIRE

    Aboufadel, Edward F.

    2014-01-01

    The purpose of this short paper is to describe a project to manufacture a regular octohedron on a 3D printer. We assume that the reader is familiar with the basics of 3D printing. In the project, we use fundamental ideas to calculate the vertices and faces of an octohedron. Then, we utilize the OPENSCAD program to create a virtual 3D model and an STereoLithography (.stl) file that can be used by a 3D printer.

  19. Salient Local 3D Features for 3D Shape Retrieval

    CERN Document Server

    Godil, Afzal

    2011-01-01

    In this paper we describe a new formulation for the 3D salient local features based on the voxel grid inspired by the Scale Invariant Feature Transform (SIFT). We use it to identify the salient keypoints (invariant points) on a 3D voxelized model and calculate invariant 3D local feature descriptors at these keypoints. We then use the bag of words approach on the 3D local features to represent the 3D models for shape retrieval. The advantages of the method are that it can be applied to rigid as well as to articulated and deformable 3D models. Finally, this approach is applied for 3D Shape Retrieval on the McGill articulated shape benchmark and then the retrieval results are presented and compared to other methods.

  20. 1D-3D mixed-ligand frameworks with an unusual dmp topology tuned by intersection angles of isomeric benzenedicarboxylates: magnetic properties, gas-dependent calcination-thermolysis and energy storage performances.

    Science.gov (United States)

    Li, Zuo-Xi; Ye, Gan; Han, Juan; Yang, Ying; Zou, Kang-Yu; Wang, Xin; Wang, Xiao-Ling; Gou, Xiao-Feng

    2015-05-21

    In this work, three isomeric benzenedicarboxylates, 1,2-benzenedicarboxylic acid (o-H2bdc), 1,3-benzenedicarboxylic acid (m-H2bdc), and 1,4-benzenedicarboxylic acid (p-H2bdc) have been utilized as the ancillary ligands to perform a systematic study on the structural diversity of mixed-ligand frameworks. The solvothermal reactions of Co(NO3)2 with these aromatic acids and the primary ligand 4,4'-bis(imidazolyl)biphenyl (bibp) afford three novel coordination polymers, {[Co6(bibp)3(o-bdc)6(H2O)](CH3CN)1.5}∞ (1), [Co(bibp)(m-bdc)]∞ (2), and [Co(bibp)(p-bdc)]∞ (3). Owing to the different orientations of the carboxylate groups, the benzenedicarboxylates adopt various bridging modes to connect the Co(II) ions into a series of 1D carboxylate∩cobalt architectures based on the 1D chain, binuclear and single-ion magnetic units, respectively. These 1D architectures are further decorated by the bibp ligand to afford a 1D belt for , 2D double-bridging (4,4) sheet for 2, and an unusual 3D dmp framework for 3. Significantly in 3, three equivalent frameworks are interlocked with each other to represent an unprecedented three-fold interpenetrating dmp network. The structural diversity indicates that the benzenedicarboxylate plays an essential role in the assembly of mixed-ligand frameworks, and the orientation of the carboxylate group exerts an important influence on the nucleation, dimensionality and also interpenetration. Furthermore, the magnetic properties of 1 and 2 have been studied by fitting the experimental data as possible, and the magneto-structural correlation of 2 has also been well discussed. Importantly, CoO and Co3O4 were obtained from the controllable thermolysis of crystals of 1 via simple calcination treatment under different gas environments. The as-synthesized cobalt oxides display good crystallinity and appear as micro- or nanoparticles, which can be applied as supercapacitor electrodes as demonstrated by their energy storage performance in 2 M KOH

  1. Field topologies in ideal and near ideal magnetohydrodynamics and vortex dynamics

    CERN Document Server

    Low, B C

    2014-01-01

    Magnetic field topology frozen in ideal magnetohydrodynamics (MHD) and its breakage in near ideal MHD are reviewed in two parts. The first part gives a physically complete description of the frozen in field topology, taking magnetic flux conservation as fundamental and treating four topics, Eulerian and Lagrangian descriptions of MHD, Chandrasekhar-Kendall and Euler-potential field representations, magnetic helicity, and inviscid vortex dynamics in comparison to ideal MHD. A corollary clarifies the challenge of achieving a high degree of the frozen in condition in numerical MHD. The second part treats field topology breakage centered on the Parker Magnetostatic Theorem on a general incompatibility of a continuous magnetic field with the dual demand of force free equilibrium and an arbitrarily prescribed, 3D field topology. Preserving field topology as a global constraint readily results in formation of tangential magnetic discontinuities, i.e., electric current sheets of zero thickness. A similar incompatibil...

  2. Preoperative assessment of vascular anatomy of inferior mesenteric artery by volume-rendered 3D-CT for laparoscopic lymph node dissection with left colic artery preservation in lower sigmoid and rectal cancer

    Institute of Scientific and Technical Information of China (English)

    Michiya Kobayashi; Satoshi Morishita; Takehiro Okabayashi; Kana Miyatake; Ken Okamoto; Tsutomu Namikawa; Yasuhiro Ogawa; Keijiro Araki

    2006-01-01

    AIM: To determine the distance between the branching point of the left colic artery (LCA) and the inferior mesenteric artery (IMA) by computed tomography (CT) scanning, for preoperative evaluation before laparoscopic colorectal operation.METHODS: From February 2004 to May 2005, 100patients (63 men, 37 women) underwent angiography performed with a 16-scanner multi-detector row CT unit (Toshiba, Aquilion 16). All images were analyzed on a workstation (AZE Ltd, Virtual Place Advance 300). The distance from the root of the IMA to the bifurcation of the LCA was measured by curved multi-planar reconstruction on a workstation.RESULTS: The IMA could be visualized in all the cases,but the LCA was missing in two patients. The mean distance from the root of the IMA to the root of the LCA was 42.0 mm (range, 23.2-75.0 mm). There were no differences in gender, arterial branching types, body weight, height, and body mass index.CONCLUSION: Volume-rendered 3D-CT is helpful to assess the vascular branching anatomy for laparoscopic surgery.

  3. 3D Cadastral Data Model Based on Conformal Geometry Algebra

    Directory of Open Access Journals (Sweden)

    Ji-yi Zhang

    2016-02-01

    Full Text Available Three-dimensional (3D cadastral data models that are based on Euclidean geometry (EG are incapable of providing a unified representation of geometry and topological relations for 3D spatial units in a cadastral database. This lack of unification causes problems such as complex expression structure and inefficiency in the updating of 3D cadastral objects. The inability of current cadastral data models to express cadastral objects in a unified manner can be attributed to the different expressions of dimensional objects. Because the hierarchical Grassmann structure corresponds to the hierarchical structure of dimensions in conformal geometric algebra (CGA, geometric objects in different dimensions can be constructed by outer products in a unified expression form, which enables the direct extension of two-dimensional (2D spatial representations to 3D spatial representations. The multivector structure in CGA can be employed to organize and store different dimensional objects in a multidimensional and unified manner. With the advantages of CGA in multidimensional expressions, a new 3D cadastral data model that is based on CGA is proposed in this paper. The geometries and topological relations of 3D spatial units can be represented in a unified form within the multivector structure. Detailed methods for 3D cadastral data model design based on CGA and data organization in CGA are introduced. The new cadastral data model is tested and analyzed with experimental data. The results indicate that the geometry and topological relations of 3D cadastral objects can be represented in a multidimensional manner with an intuitive topological structure and a unified dimensional expression.

  4. Holography of 3d-3d correspondence at Large N

    OpenAIRE

    Gang, Dongmin; Kim, Nakwoo; Lee, Sangmin

    2014-01-01

    We study the physics of multiple M5-branes compactified on a hyperbolic 3-manifold. On the one hand, it leads to the 3d-3d correspondence which maps an N = 2 $$ \\mathcal{N}=2 $$ superconformal field theory to a pure Chern-Simons theory on the 3-manifold. On the other hand, it leads to a warped AdS 4 geometry in M-theory holographically dual to the superconformal field theory. Combining the holographic duality and the 3d-3d correspondence, we propose a conjecture for the large N limit of the p...

  5. Topology optimization for coated structures

    DEFF Research Database (Denmark)

    Clausen, Anders; Andreassen, Erik; Sigmund, Ole

    2015-01-01

    This paper presents new results within the design of three-dimensional (3D) coated structures using topology optimization.The work is an extension of a recently published two-dimensional (2D) method for including coatedstructures into the minimum compliance topology optimization problem. The high...... level of control over key parameters demonstrated for the 2D model can likewise be achieved in 3D. The effectiveness of the approach isdemonstrated with numerical examples, which for the 3D problems have been solved using a parallel topology optimization implementation based on the PETSc toolkit....

  6. 3D Building Model Fitting Using A New Kinetic Framework

    CERN Document Server

    Brédif, Mathieu; Pierrot-Deseilligny, Marc; Maître, Henri

    2008-01-01

    We describe a new approach to fit the polyhedron describing a 3D building model to the point cloud of a Digital Elevation Model (DEM). We introduce a new kinetic framework that hides to its user the combinatorial complexity of determining or maintaining the polyhedron topology, allowing the design of a simple variational optimization. This new kinetic framework allows the manipulation of a bounded polyhedron with simple faces by specifying the target plane equations of each of its faces. It proceeds by evolving continuously from the polyhedron defined by its initial topology and its initial plane equations to a polyhedron that is as topologically close as possible to the initial polyhedron but with the new plane equations. This kinetic framework handles internally the necessary topological changes that may be required to keep the faces simple and the polyhedron bounded. For each intermediate configurations where the polyhedron looses the simplicity of its faces or its boundedness, the simplest topological mod...

  7. 3D Image Modelling and Specific Treatments in Orthodontics Domain

    Directory of Open Access Journals (Sweden)

    Dionysis Goularas

    2007-01-01

    Full Text Available In this article, we present a 3D specific dental plaster treatment system for orthodontics. From computer tomography scanner images, we propose first a 3D image modelling and reconstruction method of the Mandible and Maxillary based on an adaptive triangulation allowing management of contours meant for the complex topologies. Secondly, we present two specific treatment methods directly achieved on obtained 3D model allowing the automatic correction for the setting in occlusion of the Mandible and the Maxillary, and the teeth segmentation allowing more specific dental examinations. Finally, these specific treatments are presented via a client/server application with the aim of allowing a telediagnosis and treatment.

  8. A method of 3D modeling and codec

    Institute of Scientific and Technical Information of China (English)

    QI Yue; YANG Shen; CAI Su; HOU Fei; SHEN XuKun; ZHAO QinPing

    2009-01-01

    3D modeling and codec of real objects are hot Issues in the field of virtual reality. In this paper, we propose an automatic registration two range Images method and a cycle based automatic global reg-istration algorithm for rapidly and automatically registering all range Images and constructing a real-istic 3D model. Besides, to meet the requirement of huge data transmission over Internet, we present a 3D mesh encoding/decoding method for encoding geometry, topology and attribute data with high compression ratio and supporting progressive transmission. The research results have already been applied successfully in digital museum.

  9. 3D Spectroscopy in Astronomy

    Science.gov (United States)

    Mediavilla, Evencio; Arribas, Santiago; Roth, Martin; Cepa-Nogué, Jordi; Sánchez, Francisco

    2011-09-01

    Preface; Acknowledgements; 1. Introductory review and technical approaches Martin M. Roth; 2. Observational procedures and data reduction James E. H. Turner; 3. 3D Spectroscopy instrumentation M. A. Bershady; 4. Analysis of 3D data Pierre Ferruit; 5. Science motivation for IFS and galactic studies F. Eisenhauer; 6. Extragalactic studies and future IFS science Luis Colina; 7. Tutorials: how to handle 3D spectroscopy data Sebastian F. Sánchez, Begona García-Lorenzo and Arlette Pécontal-Rousset.

  10. Spherical 3D isotropic wavelets

    Science.gov (United States)

    Lanusse, F.; Rassat, A.; Starck, J.-L.

    2012-04-01

    Context. Future cosmological surveys will provide 3D large scale structure maps with large sky coverage, for which a 3D spherical Fourier-Bessel (SFB) analysis in spherical coordinates is natural. Wavelets are particularly well-suited to the analysis and denoising of cosmological data, but a spherical 3D isotropic wavelet transform does not currently exist to analyse spherical 3D data. Aims: The aim of this paper is to present a new formalism for a spherical 3D isotropic wavelet, i.e. one based on the SFB decomposition of a 3D field and accompany the formalism with a public code to perform wavelet transforms. Methods: We describe a new 3D isotropic spherical wavelet decomposition based on the undecimated wavelet transform (UWT) described in Starck et al. (2006). We also present a new fast discrete spherical Fourier-Bessel transform (DSFBT) based on both a discrete Bessel transform and the HEALPIX angular pixelisation scheme. We test the 3D wavelet transform and as a toy-application, apply a denoising algorithm in wavelet space to the Virgo large box cosmological simulations and find we can successfully remove noise without much loss to the large scale structure. Results: We have described a new spherical 3D isotropic wavelet transform, ideally suited to analyse and denoise future 3D spherical cosmological surveys, which uses a novel DSFBT. We illustrate its potential use for denoising using a toy model. All the algorithms presented in this paper are available for download as a public code called MRS3D at http://jstarck.free.fr/mrs3d.html

  11. 3D IBFV : Hardware-Accelerated 3D Flow Visualization

    NARCIS (Netherlands)

    Telea, Alexandru; Wijk, Jarke J. van

    2003-01-01

    We present a hardware-accelerated method for visualizing 3D flow fields. The method is based on insertion, advection, and decay of dye. To this aim, we extend the texture-based IBFV technique for 2D flow visualization in two main directions. First, we decompose the 3D flow visualization problem in a

  12. 3D Elevation Program—Virtual USA in 3D

    Science.gov (United States)

    Lukas, Vicki; Stoker, J.M.

    2016-04-14

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) uses a laser system called ‘lidar’ (light detection and ranging) to create a virtual reality map of the Nation that is very accurate. 3D maps have many uses with new uses being discovered all the time.  

  13. A 3-D Contextual Classifier

    DEFF Research Database (Denmark)

    Larsen, Rasmus

    1997-01-01

    . This includes the specification of a Gaussian distribution for the pixel values as well as a prior distribution for the configuration of class variables within the cross that is m ade of a pixel and its four nearest neighbours. We will extend this algorithm to 3-D, i.e. we will specify a simultaneous Gaussian...... distr ibution for a pixel and its 6 nearest 3-D neighbours, and generalise the class variable configuration distribution within the 3-D cross. The algorithm is tested on a synthetic 3-D multivariate dataset....

  14. 3D Bayesian contextual classifiers

    DEFF Research Database (Denmark)

    Larsen, Rasmus

    2000-01-01

    We extend a series of multivariate Bayesian 2-D contextual classifiers to 3-D by specifying a simultaneous Gaussian distribution for the feature vectors as well as a prior distribution of the class variables of a pixel and its 6 nearest 3-D neighbours.......We extend a series of multivariate Bayesian 2-D contextual classifiers to 3-D by specifying a simultaneous Gaussian distribution for the feature vectors as well as a prior distribution of the class variables of a pixel and its 6 nearest 3-D neighbours....

  15. Using 3D in Visualization

    DEFF Research Database (Denmark)

    Wood, Jo; Kirschenbauer, Sabine; Döllner, Jürgen

    2005-01-01

    to display 3D imagery. The extra cartographic degree of freedom offered by using 3D is explored and offered as a motivation for employing 3D in visualization. The use of VR and the construction of virtual environments exploit navigational and behavioral realism, but become most usefil when combined...... with abstracted representations embedded in a 3D space. The interactions between development of geovisualization, the technology used to implement it and the theory surrounding cartographic representation are explored. The dominance of computing technologies, driven particularly by the gaming industry...

  16. Interactive 3D multimedia content

    CERN Document Server

    Cellary, Wojciech

    2012-01-01

    The book describes recent research results in the areas of modelling, creation, management and presentation of interactive 3D multimedia content. The book describes the current state of the art in the field and identifies the most important research and design issues. Consecutive chapters address these issues. These are: database modelling of 3D content, security in 3D environments, describing interactivity of content, searching content, visualization of search results, modelling mixed reality content, and efficient creation of interactive 3D content. Each chapter is illustrated with example a

  17. 3D for Graphic Designers

    CERN Document Server

    Connell, Ellery

    2011-01-01

    Helping graphic designers expand their 2D skills into the 3D space The trend in graphic design is towards 3D, with the demand for motion graphics, animation, photorealism, and interactivity rapidly increasing. And with the meteoric rise of iPads, smartphones, and other interactive devices, the design landscape is changing faster than ever.2D digital artists who need a quick and efficient way to join this brave new world will want 3D for Graphic Designers. Readers get hands-on basic training in working in the 3D space, including product design, industrial design and visualization, modeling, ani

  18. 3-D printers for libraries

    CERN Document Server

    Griffey, Jason

    2014-01-01

    As the maker movement continues to grow and 3-D printers become more affordable, an expanding group of hobbyists is keen to explore this new technology. In the time-honored tradition of introducing new technologies, many libraries are considering purchasing a 3-D printer. Jason Griffey, an early enthusiast of 3-D printing, has researched the marketplace and seen several systems first hand at the Consumer Electronics Show. In this report he introduces readers to the 3-D printing marketplace, covering such topics asHow fused deposition modeling (FDM) printing workBasic terminology such as build

  19. Volume Sculpting: Intuitive, Interactive 3D Shape Modelling

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas

    A system for interactive modelling of 3D shapes on a computer is presented. The system is intuitive and has a flat learning curve. It is especially well suited to the creation of organic shapes and shapes of complex topology. The interaction is simple; the user can either add new shape features...

  20. MAG3D and its application to internal flowfield analysis

    Science.gov (United States)

    Lee, K. D.; Henderson, T. L.; Choo, Y. K.

    1992-01-01

    MAG3D (multiblock adaptive grid, 3D) is a 3D solution-adaptive grid generation code which redistributes grid points to improve the accuracy of a flow solution without increasing the number of grid points. The code is applicable to structured grids with a multiblock topology. It is independent of the original grid generator and the flow solver. The code uses the coordinates of an initial grid and the flow solution interpolated onto the new grid. MAG3D uses a numerical mapping and potential theory to modify the grid distribution based on properties of the flow solution on the initial grid. The adaptation technique is discussed, and the capability of MAG3D is demonstrated with several internal flow examples. Advantages of using solution-adaptive grids are also shown by comparing flow solutions on adaptive grids with those on initial grids.

  1. Perception of 3D spatial relations for 3D displays

    Science.gov (United States)

    Rosen, Paul; Pizlo, Zygmunt; Hoffmann, Christoph; Popescu, Voicu S.

    2004-05-01

    We test perception of 3D spatial relations in 3D images rendered by a 3D display (Perspecta from Actuality Systems) and compare it to that of a high-resolution flat panel display. 3D images provide the observer with such depth cues as motion parallax and binocular disparity. Our 3D display is a device that renders a 3D image by displaying, in rapid succession, radial slices through the scene on a rotating screen. The image is contained in a glass globe and can be viewed from virtually any direction. In the psychophysical experiment several families of 3D objects are used as stimuli: primitive shapes (cylinders and cuboids), and complex objects (multi-story buildings, cars, and pieces of furniture). Each object has at least one plane of symmetry. On each trial an object or its "distorted" version is shown at an arbitrary orientation. The distortion is produced by stretching an object in a random direction by 40%. This distortion must eliminate the symmetry of an object. The subject's task is to decide whether or not the presented object is distorted under several viewing conditions (monocular/binocular, with/without motion parallax, and near/far). The subject's performance is measured by the discriminability d', which is a conventional dependent variable in signal detection experiments.

  2. 3D Printing for Bricks

    OpenAIRE

    ECT Team, Purdue

    2015-01-01

    Building Bytes, by Brian Peters, is a project that uses desktop 3D printers to print bricks for architecture. Instead of using an expensive custom-made printer, it uses a normal standard 3D printer which is available for everyone and makes it more accessible and also easier for fabrication.

  3. Market study: 3-D eyetracker

    Science.gov (United States)

    1977-01-01

    A market study of a proposed version of a 3-D eyetracker for initial use at NASA's Ames Research Center was made. The commercialization potential of a simplified, less expensive 3-D eyetracker was ascertained. Primary focus on present and potential users of eyetrackers, as well as present and potential manufacturers has provided an effective means of analyzing the prospects for commercialization.

  4. Spherical 3D Isotropic Wavelets

    CERN Document Server

    Lanusse, F; Starck, J -L

    2011-01-01

    Future cosmological surveys will provide 3D large scale structure maps with large sky coverage, for which a 3D Spherical Fourier-Bessel (SFB) analysis in is natural. Wavelets are particularly well-suited to the analysis and denoising of cosmological data, but a spherical 3D isotropic wavelet transform does not currently exist to analyse spherical 3D data. The aim of this paper is to present a new formalism for a spherical 3D isotropic wavelet, i.e. one based on the Fourier-Bessel decomposition of a 3D field and accompany the formalism with a public code to perform wavelet transforms. We describe a new 3D isotropic spherical wavelet decomposition based on the undecimated wavelet transform (UWT) described in Starck et al. 2006. We also present a new fast Discrete Spherical Fourier-Bessel Transform (DSFBT) based on both a discrete Bessel Transform and the HEALPIX angular pixelisation scheme. We test the 3D wavelet transform and as a toy-application, apply a denoising algorithm in wavelet space to the Virgo large...

  5. Improvement of 3D Scanner

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The disadvantage remaining in 3D scanning system and its reasons are discussed. A new host-and-slave structure with high speed image acquisition and processing system is proposed to quicken the image processing and improve the performance of 3D scanning system.

  6. Advanced 3-D Ultrasound Imaging

    DEFF Research Database (Denmark)

    Rasmussen, Morten Fischer

    to produce high quality 3-D images. Because of the large matrix transducers with integrated custom electronics, these systems are extremely expensive. The relatively low price of ultrasound scanners is one of the factors for the widespread use of ultrasound imaging. The high price tag on the high quality 3-D......The main purpose of the PhD project was to develop methods that increase the 3-D ultrasound imaging quality available for the medical personnel in the clinic. Acquiring a 3-D volume gives the medical doctor the freedom to investigate the measured anatomy in any slice desirable after the scan has...... been completed. This allows for precise measurements of organs dimensions and makes the scan more operator independent. Real-time 3-D ultrasound imaging is still not as widespread in use in the clinics as 2-D imaging. A limiting factor has traditionally been the low image quality achievable using...

  7. Using 3D in Visualization

    DEFF Research Database (Denmark)

    Wood, Jo; Kirschenbauer, Sabine; Döllner, Jürgen

    2005-01-01

    The notion of three-dimensionality is applied to five stages of the visualization pipeline. While 3D visulization is most often associated with the visual mapping and representation of data, this chapter also identifies its role in the management and assembly of data, and in the media used...... to display 3D imagery. The extra cartographic degree of freedom offered by using 3D is explored and offered as a motivation for employing 3D in visualization. The use of VR and the construction of virtual environments exploit navigational and behavioral realism, but become most usefil when combined...... with abstracted representations embedded in a 3D space. The interactions between development of geovisualization, the technology used to implement it and the theory surrounding cartographic representation are explored. The dominance of computing technologies, driven particularly by the gaming industry...

  8. 3D printing in dentistry.

    Science.gov (United States)

    Dawood, A; Marti Marti, B; Sauret-Jackson, V; Darwood, A

    2015-12-01

    3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery.

  9. 3D vision system assessment

    Science.gov (United States)

    Pezzaniti, J. Larry; Edmondson, Richard; Vaden, Justin; Hyatt, Bryan; Chenault, David B.; Kingston, David; Geulen, Vanilynmae; Newell, Scott; Pettijohn, Brad

    2009-02-01

    In this paper, we report on the development of a 3D vision system consisting of a flat panel stereoscopic display and auto-converging stereo camera and an assessment of the system's use for robotic driving, manipulation, and surveillance operations. The 3D vision system was integrated onto a Talon Robot and Operator Control Unit (OCU) such that direct comparisons of the performance of a number of test subjects using 2D and 3D vision systems were possible. A number of representative scenarios were developed to determine which tasks benefited most from the added depth perception and to understand when the 3D vision system hindered understanding of the scene. Two tests were conducted at Fort Leonard Wood, MO with noncommissioned officers ranked Staff Sergeant and Sergeant First Class. The scenarios; the test planning, approach and protocols; the data analysis; and the resulting performance assessment of the 3D vision system are reported.

  10. PLOT3D user's manual

    Science.gov (United States)

    Walatka, Pamela P.; Buning, Pieter G.; Pierce, Larry; Elson, Patricia A.

    1990-01-01

    PLOT3D is a computer graphics program designed to visualize the grids and solutions of computational fluid dynamics. Seventy-four functions are available. Versions are available for many systems. PLOT3D can handle multiple grids with a million or more grid points, and can produce varieties of model renderings, such as wireframe or flat shaded. Output from PLOT3D can be used in animation programs. The first part of this manual is a tutorial that takes the reader, keystroke by keystroke, through a PLOT3D session. The second part of the manual contains reference chapters, including the helpfile, data file formats, advice on changing PLOT3D, and sample command files.

  11. 3D painting documentation: evaluation of conservation conditions with 3D imaging and ranging techniques

    Science.gov (United States)

    Abate, D.; Menna, F.; Remondino, F.; Gattari, M. G.

    2014-06-01

    The monitoring of paintings, both on canvas and wooden support, is a crucial issue for the preservation and conservation of this kind of artworks. Many environmental factors (e.g. humidity, temperature, illumination, etc.), as well as bad conservation practices (e.g. wrong restorations, inappropriate locations, etc.), can compromise the material conditions over time and deteriorate an artwork. The article presents an on-going project realized by a multidisciplinary team composed by the ENEA UTICT 3D GraphLab, the 3D Optical Metrology Unit of the Bruno Kessler Foundation and the Soprintendenza per i Beni Storico Artistici ed Etnoantropologici of Bologna (Italy). The goal of the project is the multi-temporal 3D documentation and monitoring of paintings - at the moment in bad conservation's situation - and the provision of some metrics to quantify the deformations and damages.

  12. Topology Optimized Photonic Wire Splitters

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Borel, Peter Ingo; Jensen, Jakob Søndergaard;

    2006-01-01

    Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm.......Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm....

  13. ADT-3D Tumor Detection Assistant in 3D

    Directory of Open Access Journals (Sweden)

    Jaime Lazcano Bello

    2008-12-01

    Full Text Available The present document describes ADT-3D (Three-Dimensional Tumor Detector Assistant, a prototype application developed to assist doctors diagnose, detect and locate tumors in the brain by using CT scan. The reader may find on this document an introduction to tumor detection; ADT-3D main goals; development details; description of the product; motivation for its development; result’s study; and areas of applicability.

  14. In-home hierarchical posture classification with a time-of-flight 3D sensor.

    Science.gov (United States)

    Diraco, Giovanni; Leone, Alessandro; Siciliano, Pietro

    2014-01-01

    A non-invasive technique for posture classification suitable to be used in several in-home scenarios is proposed and preliminary validation results are presented. 3D point cloud sequences were acquired using a single time-of-flight sensor working in a privacy preserving modality and they were processed with a low power embedded PC. In order to satisfy different application requirements (e.g. covered distance range, processing speed and discrimination capabilities), a twofold discrimination approach was investigated in which features were hierarchically arranged from coarse to fine by exploiting both topological and volumetric representations. The topological representation encoded the intrinsic topology of the body's shape using a skeleton-based structure, thus guaranteeing invariance to scale, rotations and postural changes and achieving a high level of detail with a moderate computational cost. On the other hand, using the volumetric representation features were described in terms of 3D cylindrical histograms working within a wider range of distances in a faster way and also guaranteeing good invariance properties. The discrimination capabilities were evaluated in four different real-home scenarios related with the fields of ambient assisted living and homecare, namely "dangerous event detection", "anomalous behaviour detection", "activities recognition" and "natural human-ambient interaction". For each mentioned scenario, the discrimination capabilities were evaluated in terms of invariance to viewpoint changes, representation capabilities and classification performance, achieving promising results. The two feature representation approaches exhibited complementary characteristics showing high reliability with classification rates greater than 97%. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. 3D Topology optimization of Stokes flow problems

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Allan; Dammann, Bernd

    for the fluid behavior in a micro fluidic device. Such a device has finite size and a large degree of freedom for the design of geometry. Physically Stokes flow is an exotic inertia free flow. This, however, complicates mixing by passive devices. Passive devices, that is, devices without moving parts, are often......, the optimizer suggests a design that stretches the hot-cold interface, which is encouraging since "stretching and folding" is known to be key ingredients in efficient mixing. The modelling is performed using a finite element based solver, with analytically derived sensitivities that drives a gradient based...... Program Interface, http://www.openmp.org/...

  16. 3D Printed Composites for Topology Transforming Multifunctional Devices

    Science.gov (United States)

    2017-01-26

    layer was 0.5 mm in thickness, and the bottom TB layer was 1.5 mm, and hydrogel layer was 0.5mm. The radius of the hole was 0.4mm. The pillar had a...USA) at different temperatures and curing times. To record the resistance, change during curing, we fabricated two copper electrodes that connected

  17. Unassisted 3D camera calibration

    Science.gov (United States)

    Atanassov, Kalin; Ramachandra, Vikas; Nash, James; Goma, Sergio R.

    2012-03-01

    With the rapid growth of 3D technology, 3D image capture has become a critical part of the 3D feature set on mobile phones. 3D image quality is affected by the scene geometry as well as on-the-device processing. An automatic 3D system usually assumes known camera poses accomplished by factory calibration using a special chart. In real life settings, pose parameters estimated by factory calibration can be negatively impacted by movements of the lens barrel due to shaking, focusing, or camera drop. If any of these factors displaces the optical axes of either or both cameras, vertical disparity might exceed the maximum tolerable margin and the 3D user may experience eye strain or headaches. To make 3D capture more practical, one needs to consider unassisted (on arbitrary scenes) calibration. In this paper, we propose an algorithm that relies on detection and matching of keypoints between left and right images. Frames containing erroneous matches, along with frames with insufficiently rich keypoint constellations, are detected and discarded. Roll, pitch yaw , and scale differences between left and right frames are then estimated. The algorithm performance is evaluated in terms of the remaining vertical disparity as compared to the maximum tolerable vertical disparity.

  18. Bioprinting of 3D hydrogels.

    Science.gov (United States)

    Stanton, M M; Samitier, J; Sánchez, S

    2015-08-07

    Three-dimensional (3D) bioprinting has recently emerged as an extension of 3D material printing, by using biocompatible or cellular components to build structures in an additive, layer-by-layer methodology for encapsulation and culture of cells. These 3D systems allow for cell culture in a suspension for formation of highly organized tissue or controlled spatial orientation of cell environments. The in vitro 3D cellular environments simulate the complexity of an in vivo environment and natural extracellular matrices (ECM). This paper will focus on bioprinting utilizing hydrogels as 3D scaffolds. Hydrogels are advantageous for cell culture as they are highly permeable to cell culture media, nutrients, and waste products generated during metabolic cell processes. They have the ability to be fabricated in customized shapes with various material properties with dimensions at the micron scale. 3D hydrogels are a reliable method for biocompatible 3D printing and have applications in tissue engineering, drug screening, and organ on a chip models.

  19. Tuotekehitysprojekti: 3D-tulostin

    OpenAIRE

    Pihlajamäki, Janne

    2011-01-01

    Opinnäytetyössä tutustuttiin 3D-tulostamisen teknologiaan. Työssä käytiin läpi 3D-tulostimesta tehty tuotekehitysprojekti. Sen lisäksi esiteltiin yleisellä tasolla tuotekehitysprosessi ja syntyneiden tulosten mahdollisia suojausmenetelmiä. Tavoitteena tässä työssä oli kehittää markkinoilta jo löytyvää kotitulostin-tasoista 3D-laiteteknologiaa lähemmäksi ammattilaistason ratkaisua. Tavoitteeseen pyrittiin keskittymällä parantamaan laitteella saavutettavaa tulostustarkkuutta ja -nopeutt...

  20. Color 3D Reverse Engineering

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper presents a principle and a method of col or 3D laser scanning measurement. Based on the fundamental monochrome 3D measureme nt study, color information capture, color texture mapping, coordinate computati on and other techniques are performed to achieve color 3D measurement. The syste m is designed and composed of a line laser light emitter, one color CCD camera, a motor-driven rotary filter, a circuit card and a computer. Two steps in captu ring object's images in the measurement process: Firs...

  1. Exploration of 3D Printing

    OpenAIRE

    Lin, Zeyu

    2014-01-01

    3D printing technology is introduced and defined in this Thesis. Some methods of 3D printing are illustrated and their principles are explained with pictures. Most of the essential parts are presented with pictures and their effects are explained within the whole system. Problems on Up! Plus 3D printer are solved and a DIY product is made with this machine. The processes of making product are recorded and the items which need to be noticed during the process are the highlight in this th...

  2. Handbook of 3D integration

    CERN Document Server

    Garrou , Philip; Ramm , Peter

    2014-01-01

    Edited by key figures in 3D integration and written by top authors from high-tech companies and renowned research institutions, this book covers the intricate details of 3D process technology.As such, the main focus is on silicon via formation, bonding and debonding, thinning, via reveal and backside processing, both from a technological and a materials science perspective. The last part of the book is concerned with assessing and enhancing the reliability of the 3D integrated devices, which is a prerequisite for the large-scale implementation of this emerging technology. Invaluable reading fo

  3. Topological Active Volumes

    Directory of Open Access Journals (Sweden)

    Barreira N

    2005-01-01

    Full Text Available The topological active volumes (TAVs model is a general model for 3D image segmentation. It is based on deformable models and integrates features of region-based and boundary-based segmentation techniques. Besides segmentation, it can also be used for surface reconstruction and topological analysis of the inside of detected objects. The TAV structure is flexible and allows topological changes in order to improve the adjustment to object's local characteristics, find several objects in the scene, and identify and delimit holes in detected structures. This paper describes the main features of the TAV model and shows its ability to segment volumes in an automated manner.

  4. Formal representation of 3D structural geological models

    Science.gov (United States)

    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.

  5. Reconstruction of High Resolution 3D Objects from Incomplete Images and 3D Information

    Directory of Open Access Journals (Sweden)

    Alexander Pacheco

    2014-05-01

    Full Text Available To this day, digital object reconstruction is a quite complex area that requires many techniques and novel approaches, in which high-resolution 3D objects present one of the biggest challenges. There are mainly two different methods that can be used to reconstruct high resolution objects and images: passive methods and active methods. This methods depend on the type of information available as input for modeling 3D objects. The passive methods use information contained in the images and the active methods make use of controlled light sources, such as lasers. The reconstruction of 3D objects is quite complex and there is no unique solution- The use of specific methodologies for the reconstruction of certain objects it’s also very common, such as human faces, molecular structures, etc. This paper proposes a novel hybrid methodology, composed by 10 phases that combine active and passive methods, using images and a laser in order to supplement the missing information and obtain better results in the 3D object reconstruction. Finally, the proposed methodology proved its efficiency in two complex topological complex objects.

  6. 3D Face Recognition with Sparse Spherical Representations

    CERN Document Server

    Llonch, R Sala; Tosic, I; Frossard, P

    2008-01-01

    This paper addresses the problem of 3D face recognition using simultaneous sparse approximations on the sphere. The 3D face point clouds are first aligned with a novel and fully automated registration process. They are then represented as signals on the 2D sphere in order to preserve depth and geometry information. Next, we implement a dimensionality reduction process with simultaneous sparse approximations and subspace projection. It permits to represent each 3D face by only a few spherical functions that are able to capture the salient facial characteristics, and hence to preserve the discriminant facial information. We eventually perform recognition by effective matching in the reduced space, where Linear Discriminant Analysis can be further activated for improved recognition performance. The 3D face recognition algorithm is evaluated on the FRGC v.1.0 data set, where it is shown to outperform classical state-of-the-art solutions that work with depth images.

  7. Conducting polymer 3D microelectrodes

    DEFF Research Database (Denmark)

    Sasso, Luigi; Vazquez, Patricia; Vedarethinam, Indumathi

    2010-01-01

    Conducting polymer 3D microelectrodes have been fabricated for possible future neurological applications. A combination of micro-fabrication techniques and chemical polymerization methods has been used to create pillar electrodes in polyaniline and polypyrrole. The thin polymer films obtained...

  8. Accepting the T3D

    Energy Technology Data Exchange (ETDEWEB)

    Rich, D.O.; Pope, S.C.; DeLapp, J.G.

    1994-10-01

    In April, a 128 PE Cray T3D was installed at Los Alamos National Laboratory`s Advanced Computing Laboratory as part of the DOE`s High-Performance Parallel Processor Program (H4P). In conjunction with CRI, the authors implemented a 30 day acceptance test. The test was constructed in part to help them understand the strengths and weaknesses of the T3D. In this paper, they briefly describe the H4P and its goals. They discuss the design and implementation of the T3D acceptance test and detail issues that arose during the test. They conclude with a set of system requirements that must be addressed as the T3D system evolves.

  9. 3-D Vector Flow Imaging

    DEFF Research Database (Denmark)

    Holbek, Simon

    For the last decade, the field of ultrasonic vector flow imaging has gotten an increasingly attention, as the technique offers a variety of new applications for screening and diagnostics of cardiovascular pathologies. The main purpose of this PhD project was therefore to advance the field of 3-D...... ultrasonic vector flow estimation and bring it a step closer to a clinical application. A method for high frame rate 3-D vector flow estimation in a plane using the transverse oscillation method combined with a 1024 channel 2-D matrix array is presented. The proposed method is validated both through phantom......, if this significant reduction in the element count can still provide precise and robust 3-D vector flow estimates in a plane. The study concludes that the RC array is capable of estimating precise 3-D vector flow both in a plane and in a volume, despite the low channel count. However, some inherent new challenges...

  10. 3D Face Apperance Model

    DEFF Research Database (Denmark)

    Lading, Brian; Larsen, Rasmus; Astrom, K

    2006-01-01

    We build a 3D face shape model, including inter- and intra-shape variations, derive the analytical Jacobian of its resulting 2D rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations......We build a 3D face shape model, including inter- and intra-shape variations, derive the analytical Jacobian of its resulting 2D rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations...

  11. 3D Face Appearance Model

    DEFF Research Database (Denmark)

    Lading, Brian; Larsen, Rasmus; Åström, Kalle

    2006-01-01

    We build a 3d face shape model, including inter- and intra-shape variations, derive the analytical jacobian of its resulting 2d rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations.}......We build a 3d face shape model, including inter- and intra-shape variations, derive the analytical jacobian of its resulting 2d rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations.}...

  12. Main: TATCCAYMOTIFOSRAMY3D [PLACE

    Lifescience Database Archive (English)

    Full Text Available TATCCAYMOTIFOSRAMY3D S000256 01-August-2006 (last modified) kehi TATCCAY motif foun...d in rice (O.s.) RAmy3D alpha-amylase gene promoter; Y=T/C; a GATA motif as its antisense sequence; TATCCAY ...motif and G motif (see S000130) are responsible for sugar repression (Toyofuku et al. 1998); GATA; amylase; sugar; repression; rice (Oryza sativa) TATCCAY ...

  13. MPML3D: Scripting Agents for the 3D Internet.

    Science.gov (United States)

    Prendinger, Helmut; Ullrich, Sebastian; Nakasone, Arturo; Ishizuka, Mitsuru

    2011-05-01

    The aim of this paper is two-fold. First, it describes a scripting language for specifying communicative behavior and interaction of computer-controlled agents ("bots") in the popular three-dimensional (3D) multiuser online world of "Second Life" and the emerging "OpenSimulator" project. While tools for designing avatars and in-world objects in Second Life exist, technology for nonprogrammer content creators of scenarios involving scripted agents is currently missing. Therefore, we have implemented new client software that controls bots based on the Multimodal Presentation Markup Language 3D (MPML3D), a highly expressive XML-based scripting language for controlling the verbal and nonverbal behavior of interacting animated agents. Second, the paper compares Second Life and OpenSimulator platforms and discusses the merits and limitations of each from the perspective of agent control. Here, we also conducted a small study that compares the network performance of both platforms.

  14. 3D-mallinnus ja 3D-animaatiot biovoimalaitoksesta

    OpenAIRE

    Hiltula, Tytti

    2014-01-01

    Opinnäytetyössä tehtiin biovoimalaitoksen piirustuksista 3D-mallinnus ja animaatiot. Työn tarkoituksena oli saada valmiiksi Recwell Oy:lle markkinointiin tarkoitetut kuva- ja videomateriaalit. Työssä perehdyttiin 3D-mallintamisen perustietoihin ja lähtökohtiin sekä animaation laatimiseen. Työ laadittiin kokonaisuudessaan AutoCAD-ohjelmalla, ja työn aikana tutustuttiin huolellisesti myös ohjelman käyttöohjeisiin. Piirustusten mitoituksessa huomattiin jo alkuvaiheessa suuria puutteita, ...

  15. From 3D view to 3D print

    Science.gov (United States)

    Dima, M.; Farisato, G.; Bergomi, M.; Viotto, V.; Magrin, D.; Greggio, D.; Farinato, J.; Marafatto, L.; Ragazzoni, R.; Piazza, D.

    2014-08-01

    In the last few years 3D printing is getting more and more popular and used in many fields going from manufacturing to industrial design, architecture, medical support and aerospace. 3D printing is an evolution of bi-dimensional printing, which allows to obtain a solid object from a 3D model, realized with a 3D modelling software. The final product is obtained using an additive process, in which successive layers of material are laid down one over the other. A 3D printer allows to realize, in a simple way, very complex shapes, which would be quite difficult to be produced with dedicated conventional facilities. Thanks to the fact that the 3D printing is obtained superposing one layer to the others, it doesn't need any particular work flow and it is sufficient to simply draw the model and send it to print. Many different kinds of 3D printers exist based on the technology and material used for layer deposition. A common material used by the toner is ABS plastics, which is a light and rigid thermoplastic polymer, whose peculiar mechanical properties make it diffusely used in several fields, like pipes production and cars interiors manufacturing. I used this technology to create a 1:1 scale model of the telescope which is the hardware core of the space small mission CHEOPS (CHaracterising ExOPlanets Satellite) by ESA, which aims to characterize EXOplanets via transits observations. The telescope has a Ritchey-Chrétien configuration with a 30cm aperture and the launch is foreseen in 2017. In this paper, I present the different phases for the realization of such a model, focusing onto pros and cons of this kind of technology. For example, because of the finite printable volume (10×10×12 inches in the x, y and z directions respectively), it has been necessary to split the largest parts of the instrument in smaller components to be then reassembled and post-processed. A further issue is the resolution of the printed material, which is expressed in terms of layers

  16. The star-triangle relation and 3d superconformal indices

    CERN Document Server

    Gahramanov, I

    2015-01-01

    Superconformal indices of 3d N=2 supersymmetric field theories are investigated from the Yang-Baxter equation point of view. Solutions of the star-triangle relation, vertex and IRF Yang-Baxter equations are expressed in terms of the q-special functions associated with these 3d indices. For a two-dimensional monopole-spin system on the square lattice a free energy per spin is explicitly determined. Similar to the partition functions, superconformal indices of 3d theories with the chiral symmetry breaking reduce to Dirac delta functions with the support on chemical potentials of the preserved flavor groups.

  17. YouDash3D: exploring stereoscopic 3D gaming for 3D movie theaters

    Science.gov (United States)

    Schild, Jonas; Seele, Sven; Masuch, Maic

    2012-03-01

    Along with the success of the digitally revived stereoscopic cinema, events beyond 3D movies become attractive for movie theater operators, i.e. interactive 3D games. In this paper, we present a case that explores possible challenges and solutions for interactive 3D games to be played by a movie theater audience. We analyze the setting and showcase current issues related to lighting and interaction. Our second focus is to provide gameplay mechanics that make special use of stereoscopy, especially depth-based game design. Based on these results, we present YouDash3D, a game prototype that explores public stereoscopic gameplay in a reduced kiosk setup. It features live 3D HD video stream of a professional stereo camera rig rendered in a real-time game scene. We use the effect to place the stereoscopic effigies of players into the digital game. The game showcases how stereoscopic vision can provide for a novel depth-based game mechanic. Projected trigger zones and distributed clusters of the audience video allow for easy adaptation to larger audiences and 3D movie theater gaming.

  18. Materialedreven 3d digital formgivning

    DEFF Research Database (Denmark)

    Hansen, Flemming Tvede

    2010-01-01

    Formålet med forskningsprojektet er for det første at understøtte keramikeren i at arbejde eksperimenterende med digital formgivning, og for det andet at bidrage til en tværfaglig diskurs om brugen af digital formgivning. Forskningsprojektet fokuserer på 3d formgivning og derved på 3d digital...... formgivning og Rapid Prototyping (RP). RP er en fællesbetegnelse for en række af de teknikker, der muliggør at overføre den digitale form til 3d fysisk form. Forskningsprojektet koncentrerer sig om to overordnede forskningsspørgsmål. Det første handler om, hvordan viden og erfaring indenfor det keramiske...... fagområde kan blive udnyttet i forhold til 3d digital formgivning. Det andet handler om, hvad en sådan tilgang kan bidrage med, og hvordan den kan blive udnyttet i et dynamisk samspil med det keramiske materiale i formgivningen af 3d keramiske artefakter. Materialedreven formgivning er karakteriseret af en...

  19. Novel 3D media technologies

    CERN Document Server

    Dagiuklas, Tasos

    2015-01-01

    This book describes recent innovations in 3D media and technologies, with coverage of 3D media capturing, processing, encoding, and adaptation, networking aspects for 3D Media, and quality of user experience (QoE). The contributions are based on the results of the FP7 European Project ROMEO, which focuses on new methods for the compression and delivery of 3D multi-view video and spatial audio, as well as the optimization of networking and compression jointly across the future Internet. The delivery of 3D media to individual users remains a highly challenging problem due to the large amount of data involved, diverse network characteristics and user terminal requirements, as well as the user’s context such as their preferences and location. As the number of visual views increases, current systems will struggle to meet the demanding requirements in terms of delivery of consistent video quality to fixed and mobile users. ROMEO will present hybrid networking solutions that combine the DVB-T2 and DVB-NGH broadcas...

  20. 3D future internet media

    CERN Document Server

    Dagiuklas, Tasos

    2014-01-01

    This book describes recent innovations in 3D media and technologies, with coverage of 3D media capturing, processing, encoding, and adaptation, networking aspects for 3D Media, and quality of user experience (QoE). The main contributions are based on the results of the FP7 European Projects ROMEO, which focus on new methods for the compression and delivery of 3D multi-view video and spatial audio, as well as the optimization of networking and compression jointly across the Future Internet (www.ict-romeo.eu). The delivery of 3D media to individual users remains a highly challenging problem due to the large amount of data involved, diverse network characteristics and user terminal requirements, as well as the user’s context such as their preferences and location. As the number of visual views increases, current systems will struggle to meet the demanding requirements in terms of delivery of constant video quality to both fixed and mobile users. ROMEO will design and develop hybrid-networking solutions that co...

  1. Speaking Volumes About 3-D

    Science.gov (United States)

    2002-01-01

    In 1999, Genex submitted a proposal to Stennis Space Center for a volumetric 3-D display technique that would provide multiple users with a 360-degree perspective to simultaneously view and analyze 3-D data. The futuristic capabilities of the VolumeViewer(R) have offered tremendous benefits to commercial users in the fields of medicine and surgery, air traffic control, pilot training and education, computer-aided design/computer-aided manufacturing, and military/battlefield management. The technology has also helped NASA to better analyze and assess the various data collected by its satellite and spacecraft sensors. Genex capitalized on its success with Stennis by introducing two separate products to the commercial market that incorporate key elements of the 3-D display technology designed under an SBIR contract. The company Rainbow 3D(R) imaging camera is a novel, three-dimensional surface profile measurement system that can obtain a full-frame 3-D image in less than 1 second. The third product is the 360-degree OmniEye(R) video system. Ideal for intrusion detection, surveillance, and situation management, this unique camera system offers a continuous, panoramic view of a scene in real time.

  2. Modification of 3D milling machine to 3D printer

    OpenAIRE

    Halamíček, Lukáš

    2015-01-01

    Tato práce se zabývá přestavbou gravírovací frézky na 3D tiskárnu. V první části se práce zabývá možnými technologiemi 3D tisku a možností jejich využití u přestavby. Dále jsou popsány a vybrány vhodné součásti pro přestavbu. V další části je realizováno řízení ohřevu podložky, trysky a řízení posuvu drátu pomocí softwaru TwinCat od společnosti Beckhoff na průmyslovém počítači. Výsledkem práce by měla být oživená 3D tiskárna. This thesis deals with rebuilding of engraving machine to 3D pri...

  3. Aspects of defects in 3d-3d correspondence

    Energy Technology Data Exchange (ETDEWEB)

    Gang, Dongmin [Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo,Chiba 277-8583 (Japan); Kim, Nakwoo [Department of Physics and Research Institute of Basic Science, Kyung Hee University,Seoul 02447 (Korea, Republic of); School of Physics, Korea Institute for Advanced Study,Seoul 02455 (Korea, Republic of); Romo, Mauricio; Yamazaki, Masahito [Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo,Chiba 277-8583 (Japan); School of Natural Sciences, Institute for Advanced Study,Princeton, NJ 08540 (United States)

    2016-10-12

    In this paper we study supersymmetric co-dimension 2 and 4 defects in the compactification of the 6d (2,0) theory of type A{sub N−1} on a 3-manifold M. The so-called 3d-3d correspondence is a relation between complexified Chern-Simons theory (with gauge group SL(N,ℂ)) on M and a 3d N=2 theory T{sub N}[M]. We study this correspondence in the presence of supersymmetric defects, which are knots/links inside the 3-manifold. Our study employs a number of different methods: state-integral models for complex Chern-Simons theory, cluster algebra techniques, domain wall theory T[SU(N)], 5d N=2 SYM, and also supergravity analysis through holography. These methods are complementary and we find agreement between them. In some cases the results lead to highly non-trivial predictions on the partition function. Our discussion includes a general expression for the cluster partition function, which can be used to compute in the presence of maximal and certain class of non-maximal punctures when N>2. We also highlight the non-Abelian description of the 3d N=2T{sub N}[M] theory with defect included, when such a description is available. This paper is a companion to our shorter paper http://dx.doi.org/10.1088/1751-8113/49/30/30LT02, which summarizes our main results.

  4. Aspects of defects in 3d-3d correspondence

    Science.gov (United States)

    Gang, Dongmin; Kim, Nakwoo; Romo, Mauricio; Yamazaki, Masahito

    2016-10-01

    In this paper we study supersymmetric co-dimension 2 and 4 defects in the compactification of the 6d (2, 0) theory of type A N -1 on a 3-manifold M . The so-called 3d-3d correspondence is a relation between complexified Chern-Simons theory (with gauge group SL(N,C) ) on M and a 3d N=2 theory T N [ M ]. We study this correspondence in the presence of supersymmetric defects, which are knots/links inside the 3-manifold. Our study employs a number of different methods: state-integral models for complex Chern-Simons theory, cluster algebra techniques, domain wall theory T [SU( N )], 5d N=2 SYM, and also supergravity analysis through holography. These methods are complementary and we find agreement between them. In some cases the results lead to highly non-trivial predictions on the partition function. Our discussion includes a general expression for the cluster partition function, which can be used to compute in the presence of maximal and certain class of non-maximal punctures when N > 2. We also highlight the non-Abelian description of the 3d N=2 T N [ M ] theory with defect included, when such a description is available. This paper is a companion to our shorter paper [1], which summarizes our main results.

  5. Holography of 3d-3d correspondence at large N

    Energy Technology Data Exchange (ETDEWEB)

    Gang, Dongmin [School of Physics, Korea Institute for Advanced Study,85 Hoegiro, Dongdaemun-gu, Seoul, 130-722 (Korea, Republic of); Kim, Nakwoo [Department of Physics and Research Institute of Basic Science, Kyung Hee University,26 Kyungheedaero, Dongdaemun-gu, Seoul, 130-701 (Korea, Republic of); Lee, Sangmin [School of Physics, Korea Institute for Advanced Study,85 Hoegiro, Dongdaemun-gu, Seoul, 130-722 (Korea, Republic of); Center for Theoretical Physics, Department of Physics and Astronomy, College of Liberal Studies,Seoul National University, 1 Gwanakro, Gwanak-gu, Seoul, 151-742 (Korea, Republic of)

    2015-04-20

    We study the physics of multiple M5-branes compactified on a hyperbolic 3-manifold. On the one hand, it leads to the 3d-3d correspondence which maps an N=2 superconformal field theory to a pure Chern-Simons theory on the 3-manifold. On the other hand, it leads to a warped AdS{sub 4} geometry in M-theory holographically dual to the superconformal field theory. Combining the holographic duality and the 3d-3d correspondence, we propose a conjecture for the large N limit of the perturbative free energy of a Chern-Simons theory on hyperbolic 3-manifold. The conjecture claims that the tree, one-loop and two-loop terms all share the same N{sup 3} scaling behavior and are proportional to the volume of the 3-manifold, while the three-loop and higher terms are suppressed at large N. Under mild assumptions, we prove the tree and one-loop parts of the conjecture. For the two-loop part, we test the conjecture numerically in a number of examples and find precise agreement. We also confirm the suppression of higher loop terms in a few examples.

  6. 3D vector flow imaging

    DEFF Research Database (Denmark)

    Pihl, Michael Johannes

    The main purpose of this PhD project is to develop an ultrasonic method for 3D vector flow imaging. The motivation is to advance the field of velocity estimation in ultrasound, which plays an important role in the clinic. The velocity of blood has components in all three spatial dimensions, yet...... conventional methods can estimate only the axial component. Several approaches for 3D vector velocity estimation have been suggested, but none of these methods have so far produced convincing in vivo results nor have they been adopted by commercial manufacturers. The basis for this project is the Transverse...... on the TO fields are suggested. They can be used to optimize the TO method. In the third part, a TO method for 3D vector velocity estimation is proposed. It employs a 2D phased array transducer and decouples the velocity estimation into three velocity components, which are estimated simultaneously based on 5...

  7. Markerless 3D Face Tracking

    DEFF Research Database (Denmark)

    Walder, Christian; Breidt, Martin; Bulthoff, Heinrich

    2009-01-01

    We present a novel algorithm for the markerless tracking of deforming surfaces such as faces. We acquire a sequence of 3D scans along with color images at 40Hz. The data is then represented by implicit surface and color functions, using a novel partition-of-unity type method of efficiently...... combining local regressors using nearest neighbor searches. Both these functions act on the 4D space of 3D plus time, and use temporal information to handle the noise in individual scans. After interactive registration of a template mesh to the first frame, it is then automatically deformed to track...... the scanned surface, using the variation of both shape and color as features in a dynamic energy minimization problem. Our prototype system yields high-quality animated 3D models in correspondence, at a rate of approximately twenty seconds per timestep. Tracking results for faces and other objects...

  8. 3-D Vector Flow Imaging

    DEFF Research Database (Denmark)

    Holbek, Simon

    studies and in vivo. Phantom measurements are compared with their corresponding reference value, whereas the in vivo measurement is validated against the current golden standard for non-invasive blood velocity estimates, based on magnetic resonance imaging (MRI). The study concludes, that a high precision......, if this significant reduction in the element count can still provide precise and robust 3-D vector flow estimates in a plane. The study concludes that the RC array is capable of estimating precise 3-D vector flow both in a plane and in a volume, despite the low channel count. However, some inherent new challenges......For the last decade, the field of ultrasonic vector flow imaging has gotten an increasingly attention, as the technique offers a variety of new applications for screening and diagnostics of cardiovascular pathologies. The main purpose of this PhD project was therefore to advance the field of 3-D...

  9. Minimal massive 3D gravity

    NARCIS (Netherlands)

    Bergshoeff, Eric; Hohm, Olaf; Merbis, Wout; Routh, Alasdair J.; Townsend, Paul K.

    2014-01-01

    We present an alternative to topologically massive gravity (TMG) with the same 'minimal' bulk properties; i.e. a single local degree of freedom that is realized as a massive graviton in linearization about an anti-de Sitter (AdS) vacuum. However, in contrast to TMG, the new 'minimal massive gravity'

  10. Microfluidic 3D Helix Mixers

    Directory of Open Access Journals (Sweden)

    Georgette B. Salieb-Beugelaar

    2016-10-01

    Full Text Available Polymeric microfluidic systems are well suited for miniaturized devices with complex functionality, and rapid prototyping methods for 3D microfluidic structures are increasingly used. Mixing at the microscale and performing chemical reactions at the microscale are important applications of such systems and we therefore explored feasibility, mixing characteristics and the ability to control a chemical reaction in helical 3D channels produced by the emerging thread template method. Mixing at the microscale is challenging because channel size reduction for improving solute diffusion comes at the price of a reduced Reynolds number that induces a strictly laminar flow regime and abolishes turbulence that would be desired for improved mixing. Microfluidic 3D helix mixers were rapidly prototyped in polydimethylsiloxane (PDMS using low-surface energy polymeric threads, twisted to form 2-channel and 3-channel helices. Structure and flow characteristics were assessed experimentally by microscopy, hydraulic measurements and chromogenic reaction, and were modeled by computational fluid dynamics. We found that helical 3D microfluidic systems produced by thread templating allow rapid prototyping, can be used for mixing and for controlled chemical reaction with two or three reaction partners at the microscale. Compared to the conventional T-shaped microfluidic system used as a control device, enhanced mixing and faster chemical reaction was found to occur due to the combination of diffusive mixing in small channels and flow folding due to the 3D helix shape. Thus, microfluidic 3D helix mixers can be rapidly prototyped using the thread template method and are an attractive and competitive method for fluid mixing and chemical reactions at the microscale.

  11. 3D Printed Bionic Nanodevices.

    Science.gov (United States)

    Kong, Yong Lin; Gupta, Maneesh K; Johnson, Blake N; McAlpine, Michael C

    2016-06-01

    The ability to three-dimensionally interweave biological and functional materials could enable the creation of bionic devices possessing unique and compelling geometries, properties, and functionalities. Indeed, interfacing high performance active devices with biology could impact a variety of fields, including regenerative bioelectronic medicines, smart prosthetics, medical robotics, and human-machine interfaces. Biology, from the molecular scale of DNA and proteins, to the macroscopic scale of tissues and organs, is three-dimensional, often soft and stretchable, and temperature sensitive. This renders most biological platforms incompatible with the fabrication and materials processing methods that have been developed and optimized for functional electronics, which are typically planar, rigid and brittle. A number of strategies have been developed to overcome these dichotomies. One particularly novel approach is the use of extrusion-based multi-material 3D printing, which is an additive manufacturing technology that offers a freeform fabrication strategy. This approach addresses the dichotomies presented above by (1) using 3D printing and imaging for customized, hierarchical, and interwoven device architectures; (2) employing nanotechnology as an enabling route for introducing high performance materials, with the potential for exhibiting properties not found in the bulk; and (3) 3D printing a range of soft and nanoscale materials to enable the integration of a diverse palette of high quality functional nanomaterials with biology. Further, 3D printing is a multi-scale platform, allowing for the incorporation of functional nanoscale inks, the printing of microscale features, and ultimately the creation of macroscale devices. This blending of 3D printing, novel nanomaterial properties, and 'living' platforms may enable next-generation bionic systems. In this review, we highlight this synergistic integration of the unique properties of nanomaterials with the

  12. 3D Printed Bionic Nanodevices

    Science.gov (United States)

    Kong, Yong Lin; Gupta, Maneesh K.; Johnson, Blake N.; McAlpine, Michael C.

    2016-01-01

    Summary The ability to three-dimensionally interweave biological and functional materials could enable the creation of bionic devices possessing unique and compelling geometries, properties, and functionalities. Indeed, interfacing high performance active devices with biology could impact a variety of fields, including regenerative bioelectronic medicines, smart prosthetics, medical robotics, and human-machine interfaces. Biology, from the molecular scale of DNA and proteins, to the macroscopic scale of tissues and organs, is three-dimensional, often soft and stretchable, and temperature sensitive. This renders most biological platforms incompatible with the fabrication and materials processing methods that have been developed and optimized for functional electronics, which are typically planar, rigid and brittle. A number of strategies have been developed to overcome these dichotomies. One particularly novel approach is the use of extrusion-based multi-material 3D printing, which is an additive manufacturing technology that offers a freeform fabrication strategy. This approach addresses the dichotomies presented above by (1) using 3D printing and imaging for customized, hierarchical, and interwoven device architectures; (2) employing nanotechnology as an enabling route for introducing high performance materials, with the potential for exhibiting properties not found in the bulk; and (3) 3D printing a range of soft and nanoscale materials to enable the integration of a diverse palette of high quality functional nanomaterials with biology. Further, 3D printing is a multi-scale platform, allowing for the incorporation of functional nanoscale inks, the printing of microscale features, and ultimately the creation of macroscale devices. This blending of 3D printing, novel nanomaterial properties, and ‘living’ platforms may enable next-generation bionic systems. In this review, we highlight this synergistic integration of the unique properties of nanomaterials with

  13. Optical fabrication of lightweighted 3D printed mirrors

    Science.gov (United States)

    Herzog, Harrison; Segal, Jacob; Smith, Jeremy; Bates, Richard; Calis, Jacob; De La Torre, Alyssa; Kim, Dae Wook; Mici, Joni; Mireles, Jorge; Stubbs, David M.; Wicker, Ryan

    2015-09-01

    Direct Metal Laser Sintering (DMLS) and Electron Beam Melting (EBM) 3D printing technologies were utilized to create lightweight, optical grade mirrors out of AlSi10Mg aluminum and Ti6Al4V titanium alloys at the University of Arizona in Tucson. The mirror prototypes were polished to meet the λ/20 RMS and λ/4 P-V surface figure requirements. The intent of this project was to design topologically optimized mirrors that had a high specific stiffness and low surface displacement. Two models were designed using Altair Inspire software, and the mirrors had to endure the polishing process with the necessary stiffness to eliminate print-through. Mitigating porosity of the 3D printed mirror blanks was a challenge in the face of reconciling new printing technologies with traditional optical polishing methods. The prototypes underwent Hot Isostatic Press (HIP) and heat treatment to improve density, eliminate porosity, and relieve internal stresses. Metal 3D printing allows for nearly unlimited topological constraints on design and virtually eliminates the need for a machine shop when creating an optical quality mirror. This research can lead to an increase in mirror mounting support complexity in the manufacturing of lightweight mirrors and improve overall process efficiency. The project aspired to have many future applications of light weighted 3D printed mirrors, such as spaceflight. This paper covers the design/fab/polish/test of 3D printed mirrors, thermal/structural finite element analysis, and results.

  14. Mathematical structure of three - dimensional (3D) Ising model

    CERN Document Server

    Zhang, Zhi-dong

    2013-01-01

    An overview of the mathematical structure of the three-dimensional (3D) Ising model is given, from the viewpoints of topologic, algebraic and geometric aspects. By analyzing the relations among transfer matrices of the 3D Ising model, Reidemeister moves in the knot theory, Yang-Baxter and tetrahedron equations, the following facts are illustrated for the 3D Ising model: 1) The complexified quaternion basis constructed for the 3D Ising model represents naturally the rotation in a (3 + 1) - dimensional space-time, as a relativistic quantum statistical mechanics model, which is consistent with the 4-fold integrand of the partition function by taking the time average. 2) A unitary transformation with a matrix being a spin representation in 2^(nlo)-space corresponds to a rotation in 2nlo-space, which serves to smooth all the crossings in the transfer matrices and contributes as the non-trivial topologic part of the partition function of the 3D Ising model. 3) A tetrahedron relation would ensure the commutativity o...

  15. Ideal 3D asymmetric concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Botella, Angel [Departamento Fisica Aplicada a los Recursos Naturales, Universidad Politecnica de Madrid, E.T.S.I. de Montes, Ciudad Universitaria s/n, 28040 Madrid (Spain); Fernandez-Balbuena, Antonio Alvarez; Vazquez, Daniel; Bernabeu, Eusebio [Departamento de Optica, Universidad Complutense de Madrid, Fac. CC. Fisicas, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2009-01-15

    Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used for producing reflective and refractive optical devices, including reverse engineering techniques. In this paper we apply photometric field theory and elliptic ray bundles method to study 3D asymmetric - without rotational or translational symmetry - concentrators, which can be useful components for nontracking solar applications. We study the one-sheet hyperbolic concentrator and we demonstrate its behaviour as ideal 3D asymmetric concentrator. (author)

  16. 3D digitization of mosaics

    Directory of Open Access Journals (Sweden)

    Anna Maria Manferdini

    2012-11-01

    Full Text Available In this paper we present a methodology developed to access to Cultural Heritage information using digital 3d reality-based models as graphic interfaces. The case studies presented belong to the wide repertoire of mosaics of Ravenna. One of the most peculiar characteristics of mosaics that often limits their digital survey is their multi-scale complexity; nevertheless their models could be used in 3d information systems, for digital exhibitions, for reconstruction aims and to document their conservation conditions in order to conduct restoration interventions in digital environments aiming at speeding and performing more reliable evaluations.

  17. p-topological Cauchy completions

    Directory of Open Access Journals (Sweden)

    J. Wig

    1999-01-01

    Full Text Available The duality between “regular” and “topological” as convergence space properties extends in a natural way to the more general properties “p-regular” and “p-topological.” Since earlier papers have investigated regular, p-regular, and topological Cauchy completions, we hereby initiate a study of p-topological Cauchy completions. A p-topological Cauchy space has a p-topological completion if and only if it is “cushioned,” meaning that each equivalence class of nonconvergent Cauchy filters contains a smallest filter. For a Cauchy space allowing a p-topological completion, it is shown that a certain class of Reed completions preserve the p-topological property, including the Wyler and Kowalsky completions, which are, respectively, the finest and the coarsest p-topological completions. However, not all p-topological completions are Reed completions. Several extension theorems for p-topological completions are obtained. The most interesting of these states that any Cauchy-continuous map between Cauchy spaces allowing p-topological and p′-topological completions, respectively, can always be extended to a θ-continuous map between any p-topological completion of the first space and any p′-topological completion of the second.

  18. PubChem3D: Biologically relevant 3-D similarity

    Directory of Open Access Journals (Sweden)

    Kim Sunghwan

    2011-07-01

    Full Text Available Abstract Background The use of 3-D similarity techniques in the analysis of biological data and virtual screening is pervasive, but what is a biologically meaningful 3-D similarity value? Can one find statistically significant separation between "active/active" and "active/inactive" spaces? These questions are explored using 734,486 biologically tested chemical structures, 1,389 biological assay data sets, and six different 3-D similarity types utilized by PubChem analysis tools. Results The similarity value distributions of 269.7 billion unique conformer pairs from 734,486 biologically tested compounds (all-against-all from PubChem were utilized to help work towards an answer to the question: what is a biologically meaningful 3-D similarity score? The average and standard deviation for the six similarity measures STST-opt, CTST-opt, ComboTST-opt, STCT-opt, CTCT-opt, and ComboTCT-opt were 0.54 ± 0.10, 0.07 ± 0.05, 0.62 ± 0.13, 0.41 ± 0.11, 0.18 ± 0.06, and 0.59 ± 0.14, respectively. Considering that this random distribution of biologically tested compounds was constructed using a single theoretical conformer per compound (the "default" conformer provided by PubChem, further study may be necessary using multiple diverse conformers per compound; however, given the breadth of the compound set, the single conformer per compound results may still apply to the case of multi-conformer per compound 3-D similarity value distributions. As such, this work is a critical step, covering a very wide corpus of chemical structures and biological assays, creating a statistical framework to build upon. The second part of this study explored the question of whether it was possible to realize a statistically meaningful 3-D similarity value separation between reputed biological assay "inactives" and "actives". Using the terminology of noninactive-noninactive (NN pairs and the noninactive-inactive (NI pairs to represent comparison of the "active/active" and

  19. Viewing galaxies in 3D

    CERN Document Server

    Krajnović, Davor

    2016-01-01

    Thanks to a technique that reveals galaxies in 3D, astronomers can now show that many galaxies have been wrongly classified. Davor Krajnovi\\'c argues that the classification scheme proposed 85 years ago by Edwin Hubble now needs to be revised.

  20. 3D terahertz beam profiling

    DEFF Research Database (Denmark)

    Pedersen, Pernille Klarskov; Strikwerda, Andrew; Wang, Tianwu

    2013-01-01

    We present a characterization of THz beams generated in both a two-color air plasma and in a LiNbO3 crystal. Using a commercial THz camera, we record intensity images as a function of distance through the beam waist, from which we extract 2D beam profiles and visualize our measurements into 3D beam...

  1. 3D Printing: Exploring Capabilities

    Science.gov (United States)

    Samuels, Kyle; Flowers, Jim

    2015-01-01

    As 3D printers become more affordable, schools are using them in increasing numbers. They fit well with the emphasis on product design in technology and engineering education, allowing students to create high-fidelity physical models to see and test different iterations in their product designs. They may also help students to "think in three…

  2. When Art Meets 3D

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The presentation of the vanguard work,My Dream3D,the innovative production by the China Disabled People’s Performing Art Troupe(CDPPAT),directed by Joy Joosang Park,provided the film’s domestic premiere at Beijing’s Olympic Park onApril7.The show provided an intriguing insight not

  3. 3D Printing of Metals

    Directory of Open Access Journals (Sweden)

    Manoj Gupta

    2017-09-01

    Full Text Available The potential benefits that could be derived if the science and technology of 3D printing were to be established have been the crux behind monumental efforts by governments, in most countries, that invest billions of dollars to develop this manufacturing technology.[...

  4. Making Inexpensive 3-D Models

    Science.gov (United States)

    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…

  5. 3D Printing: Exploring Capabilities

    Science.gov (United States)

    Samuels, Kyle; Flowers, Jim

    2015-01-01

    As 3D printers become more affordable, schools are using them in increasing numbers. They fit well with the emphasis on product design in technology and engineering education, allowing students to create high-fidelity physical models to see and test different iterations in their product designs. They may also help students to "think in three…

  6. 导航辅助皮层功能拓扑定位在累及功能区致痫灶手术中的初步应用%Preliminary topological trial in integrating brain mapping with 3D neuro - navigation for surgery involving eloquent cortex( case report and literature review)

    Institute of Scientific and Technical Information of China (English)

    赵晨杰; 徐纪文; 王桂松; 周洪语; 田鑫; 徐虎; 徐忠贤; 江基尧

    2011-01-01

    Objective With the help of image fusion,a 3D model of cortex covered with cortical electrodes was established.With that model,the electrophysiological information from the electrodes could be bound with gyri and sulci as point to point for analysis.A preliminary topological trial in clinical brain mapping was demonstrated,in order to improve the accuracy of localization and the outcome of surgery involving the eloquent cortex.Method One case of drug -resistant epilepsy was screened by long term video - EEG,localizing the epileptogenic zones around central areas without iateralization.There was no more valuable information could be supplied by imageology.Three subdural electrodes(4 ×8 grid; 4 ×6 grid; 1 ×6 strip) were then implanted for covering bilateral central cortex for 4 days.The long term video - ECoG and electrocortical stimulation had been applied in this period for more information about the foci and cortical function.Based on the 3D model that established by merging MRI and CT,the relationship between the foci and eloquent cortex could be shown as schemes for analysis and surgical plan.With the iastruction of neuronavigation and the schemes,the foci which was out of the funtional area would be removed and that involving would be thermocoagulated.Results Four clinical seizures were captured with three cortical electrodes and the cortical function of 52 areas were detected.Depending on the colleeted information,the operation was performed without postoperative complication.There was neither seizure nor permanent neurological deficit was shown after the surgery.Conclusions The technique of image fusion realized the visual combination of cortical electrodes and 3D brain model as a brain - computer interface.It demonstrates a preliminary topological trial for millimeter -scale human brain mapping in order to provide more accurate localization for surgery involving eloquent cortex,and would make the clinical topology of brain mapping to be true.%目的 应

  7. Priprava 3D modelov za 3D tisk

    OpenAIRE

    2015-01-01

    Po mnenju nekaterih strokovnjakov bo aditivna proizvodnja (ali 3D tiskanje) spremenila proizvodnjo industrijo, saj si bo vsak posameznik lahko natisnil svoj objekt po želji. V diplomski nalogi so predstavljene nekatere tehnologije aditivne proizvodnje. V nadaljevanju diplomske naloge je predstavljena izdelava makete hiše v merilu 1:100, vse od modeliranja do tiskanja. Poseben poudarek je posvečen predelavi modela, da je primeren za tiskanje, kjer je razvit pristop za hitrejše i...

  8. Post processing of 3D models for 3D printing

    OpenAIRE

    2015-01-01

    According to the opinion of some experts the additive manufacturing or 3D printing will change manufacturing industry, because any individual could print their own model according to his or her wishes. In this graduation thesis some of the additive manufacturing technologies are presented. Furthermore in the production of house scale model in 1:100 is presented, starting from modeling to printing. Special attention is given to postprocessing of the building model elements us...

  9. CT Image Sequence Analysis for Object Recognition - A Rule-Based 3-D Computer Vision System

    Science.gov (United States)

    Dongping Zhu; Richard W. Conners; Daniel L. Schmoldt; Philip A. Araman

    1991-01-01

    Research is now underway to create a vision system for hardwood log inspection using a knowledge-based approach. In this paper, we present a rule-based, 3-D vision system for locating and identifying wood defects using topological, geometric, and statistical attributes. A number of different features can be derived from the 3-D input scenes. These features and evidence...

  10. Discrete Scale Axis Representations for 3D Geometry

    OpenAIRE

    Miklos, Balint; Giesen, Joachim; Pauly, Mark

    2010-01-01

    This paper addresses the fundamental problem of computing stable medial representations of 3D shapes. We propose a spatially adaptive classification of geometric features that yields a robust algorithm for generating medial representations at different levels of abstraction. The recently introduced continuous scale axis transform serves as the mathematical foundation of our algorithm. We show how geometric and topological properties of the continuous setting carry over to discrete shape repre...

  11. 3D Printable Graphene Composite.

    Science.gov (United States)

    Wei, Xiaojun; Li, Dong; Jiang, Wei; Gu, Zheming; Wang, Xiaojuan; Zhang, Zengxing; Sun, Zhengzong

    2015-07-08

    In human being's history, both the Iron Age and Silicon Age thrived after a matured massive processing technology was developed. Graphene is the most recent superior material which could potentially initialize another new material Age. However, while being exploited to its full extent, conventional processing methods fail to provide a link to today's personalization tide. New technology should be ushered in. Three-dimensional (3D) printing fills the missing linkage between graphene materials and the digital mainstream. Their alliance could generate additional stream to push the graphene revolution into a new phase. Here we demonstrate for the first time, a graphene composite, with a graphene loading up to 5.6 wt%, can be 3D printable into computer-designed models. The composite's linear thermal coefficient is below 75 ppm·°C(-1) from room temperature to its glass transition temperature (Tg), which is crucial to build minute thermal stress during the printing process.

  12. Forensic 3D Scene Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    LITTLE,CHARLES Q.; PETERS,RALPH R.; RIGDON,J. BRIAN; SMALL,DANIEL E.

    1999-10-12

    Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and contribute quantitative measurements such as accurate relative positioning of crime scene objects, would be an asset to law enforcement agents in collecting and recording significant forensic data. The purpose of this project is to develop a feasible prototype of a fast, accurate, 3D measurement and imaging system that would support law enforcement agents to quickly document and accurately record a crime scene.

  13. 3D Printed Robotic Hand

    Science.gov (United States)

    Pizarro, Yaritzmar Rosario; Schuler, Jason M.; Lippitt, Thomas C.

    2013-01-01

    Dexterous robotic hands are changing the way robots and humans interact and use common tools. Unfortunately, the complexity of the joints and actuations drive up the manufacturing cost. Some cutting edge and commercially available rapid prototyping machines now have the ability to print multiple materials and even combine these materials in the same job. A 3D model of a robotic hand was designed using Creo Parametric 2.0. Combining "hard" and "soft" materials, the model was printed on the Object Connex350 3D printer with the purpose of resembling as much as possible the human appearance and mobility of a real hand while needing no assembly. After printing the prototype, strings where installed as actuators to test mobility. Based on printing materials, the manufacturing cost of the hand was $167, significantly lower than other robotic hands without the actuators since they have more complex assembly processes.

  14. Medical 3D thermography system

    OpenAIRE

    GRUBIŠIĆ, IVAN

    2011-01-01

    Infrared (IR) thermography determines the surface temperature of an object or human body using thermal IR measurement camera. It is an imaging technology which is contactless and completely non-invasive. These propertiesmake IR thermography a useful method of analysis that is used in various industrial applications to detect, monitor and predict irregularities in many fields from engineering to medical and biological observations. This paper presents a conceptual model of Medical 3D Thermo...

  15. Optimized 3D watermarking for minimal surface distortion.

    Science.gov (United States)

    Bors, Adrian G; Luo, Ming

    2013-05-01

    This paper proposes a new approach to 3D watermarking by ensuring the optimal preservation of mesh surfaces. A new 3D surface preservation function metric is defined consisting of the distance of a vertex displaced by watermarking to the original surface, to the watermarked object surface as well as the actual vertex displacement. The proposed method is statistical, blind, and robust. Minimal surface distortion according to the proposed function metric is enforced during the statistical watermark embedding stage using Levenberg-Marquardt optimization method. A study of the watermark code crypto-security is provided for the proposed methodology. According to the experimental results, the proposed methodology has high robustness against the common mesh attacks while preserving the original object surface during watermarking.

  16. 3D silicon strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Parzefall, Ulrich [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany)], E-mail: ulrich.parzefall@physik.uni-freiburg.de; Bates, Richard [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Boscardin, Maurizio [FBK-irst, Center for Materials and Microsystems, via Sommarive 18, 38050 Povo di Trento (Italy); Dalla Betta, Gian-Franco [INFN and Universita' di Trento, via Sommarive 14, 38050 Povo di Trento (Italy); Eckert, Simon [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Eklund, Lars; Fleta, Celeste [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Jakobs, Karl; Kuehn, Susanne [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Lozano, Manuel [Instituto de Microelectronica de Barcelona, IMB-CNM, CSIC, Barcelona (Spain); Pahn, Gregor [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Parkes, Chris [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Pellegrini, Giulio [Instituto de Microelectronica de Barcelona, IMB-CNM, CSIC, Barcelona (Spain); Pennicard, David [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Piemonte, Claudio; Ronchin, Sabina [FBK-irst, Center for Materials and Microsystems, via Sommarive 18, 38050 Povo di Trento (Italy); Szumlak, Tomasz [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Zoboli, Andrea [INFN and Universita' di Trento, via Sommarive 14, 38050 Povo di Trento (Italy); Zorzi, Nicola [FBK-irst, Center for Materials and Microsystems, via Sommarive 18, 38050 Povo di Trento (Italy)

    2009-06-01

    While the Large Hadron Collider (LHC) at CERN has started operation in autumn 2008, plans for a luminosity upgrade to the Super-LHC (sLHC) have already been developed for several years. This projected luminosity increase by an order of magnitude gives rise to a challenging radiation environment for tracking detectors at the LHC experiments. Significant improvements in radiation hardness are required with respect to the LHC. Using a strawman layout for the new tracker of the ATLAS experiment as an example, silicon strip detectors (SSDs) with short strips of 2-3 cm length are foreseen to cover the region from 28 to 60 cm distance to the beam. These SSD will be exposed to radiation levels up to 10{sup 15}N{sub eq}/cm{sup 2}, which makes radiation resistance a major concern for the upgraded ATLAS tracker. Several approaches to increasing the radiation hardness of silicon detectors exist. In this article, it is proposed to combine the radiation hard 3D-design originally conceived for pixel-style applications with the benefits of the established planar technology for strip detectors by using SSDs that have regularly spaced doped columns extending into the silicon bulk under the detector strips. The first 3D SSDs to become available for testing were made in the Single Type Column (STC) design, a technological simplification of the original 3D design. With such 3D SSDs, a small number of prototype sLHC detector modules with LHC-speed front-end electronics as used in the semiconductor tracking systems of present LHC experiments were built. Modules were tested before and after irradiation to fluences of 10{sup 15}N{sub eq}/cm{sup 2}. The tests were performed with three systems: a highly focused IR-laser with 5{mu}m spot size to make position-resolved scans of the charge collection efficiency, an Sr{sup 90}{beta}-source set-up to measure the signal levels for a minimum ionizing particle (MIP), and a beam test with 180 GeV pions at CERN. This article gives a brief overview of

  17. Complex crustal structures: their 3D grav/mag modelling and 3D printing

    Science.gov (United States)

    Götze, Hans-Jürgen; Schmidt, Sabine; Menzel, Peter

    2017-04-01

    Our new techniques for modelling and visualization are user-friendly because they are highly interactive, ideally real-time and topology conserving and can be used for both flat and spherical models in 3D. These are important requirements for joint inversion for gravity and magnetic modelling of fields and their derivatives, constrained by seismic and structural input from independent data sources. A borehole tool for magnetic and gravity modelling will also be introduced. We are already close to satisfying the demand of treating several geophysical methods in a single model for subsurface evaluation purposes and aim now for fulfilling most of the constraints: consistency of modelling results and measurements and geological plausibility as well. For 3D modelling, polyhedrons built by triangles are used. All elements of the gravity and magnetic tensors can be included. In the modelling interface, after geometry changes the effect on the model is quickly updated because only the changed triangles have to be recalculated. Because of the triangular model structure, our approach can handle complex structures very well and flexible (e.g. overhangs of salt domes or plumes). For regional models, the use of spherical geometries and calculations is necessary and available. 3D visualization is performed with a 3D-printer (Ultimaker 2) and gives new insights into even rather complicated Earth subsurface structures. Inversion can either be run over the whole model, but typically it is used in smaller parts of the model, helping to solve local problems and/or proving/disproving local hypotheses. The basic principles behind this interactive approach are high performance optimized algorithms (CMA-ES: Covariance-matrix-adoption-evolution-strategy). The efficiency of the algorithm is rather good in terms of stable convergence due to topological model validity. Potential field modelling is always influenced by edge effects. To avoid this, a simple but very robust method has been

  18. Visual Semantic Based 3D Video Retrieval System Using HDFS.

    Science.gov (United States)

    Kumar, C Ranjith; Suguna, S

    2016-08-01

    This paper brings out a neoteric frame of reference for visual semantic based 3d video search and retrieval applications. Newfangled 3D retrieval application spotlight on shape analysis like object matching, classification and retrieval not only sticking up entirely with video retrieval. In this ambit, we delve into 3D-CBVR (Content Based Video Retrieval) concept for the first time. For this purpose, we intent to hitch on BOVW and Mapreduce in 3D framework. Instead of conventional shape based local descriptors, we tried to coalesce shape, color and texture for feature extraction. For this purpose, we have used combination of geometric & topological features for shape and 3D co-occurrence matrix for color and texture. After thriving extraction of local descriptors, TB-PCT (Threshold Based- Predictive Clustering Tree) algorithm is used to generate visual codebook and histogram is produced. Further, matching is performed using soft weighting scheme with L2 distance function. As a final step, retrieved results are ranked according to the Index value and acknowledged to the user as a feedback .In order to handle prodigious amount of data and Efficacious retrieval, we have incorporated HDFS in our Intellection. Using 3D video dataset, we future the performance of our proposed system which can pan out that the proposed work gives meticulous result and also reduce the time intricacy.

  19. A FIB-nanotomography method for accurate 3D reconstruction of open nanoporous structures

    Energy Technology Data Exchange (ETDEWEB)

    Mangipudi, K.R., E-mail: mangipudi@ump.gwdg.de [Institut für Materialphysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, D-37077 Göttingen (Germany); Radisch, V., E-mail: vradisch@ump.gwdg.de [Institut für Materialphysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, D-37077 Göttingen (Germany); Holzer, L., E-mail: holz@zhaw.ch [Züricher Hochschule für Angewandte Wissenschaften, Institute of Computational Physics, Wildbachstrasse 21, CH-8400 Winterthur (Switzerland); Volkert, C.A., E-mail: volkert@ump.gwdg.de [Institut für Materialphysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, D-37077 Göttingen (Germany)

    2016-04-15

    We present an automated focused ion beam nanotomography method for nanoporous microstructures with open porosity, and apply it to reconstruct nanoporous gold (np-Au) structures with ligament sizes on the order of a few tens of nanometers. This method uses serial sectioning of a well-defined wedge-shaped geometry to determine the thickness of individual slices from the changes in the sample width in successive cross-sectional images. The pore space of a selected region of the np-Au is infiltrated with ion-beam-deposited Pt composite before serial sectioning. The cross-sectional images are binarized and stacked according to the individual slice thicknesses, and then processed using standard reconstruction methods. For the image conditions and sample geometry used here, we are able to determine the thickness of individual slices with an accuracy much smaller than a pixel. The accuracy of the new method based on actual slice thickness is assessed by comparing it with (i) a reconstruction using the same cross-sectional images but assuming a constant slice thickness, and (ii) a reconstruction using traditional FIB-tomography method employing constant slice thickness. The morphology and topology of the structures are characterized using ligament and pore size distributions, interface shape distribution functions, interface normal distributions, and genus. The results suggest that the morphology and topology of the final reconstructions are significantly influenced when a constant slice thickness is assumed. The study reveals grain-to-grain variations in the morphology and topology of np-Au. - Highlights: • FIB nanotomography of nanoporous structure with features sizes of ∼40 nm or less. • Accurate determination of individual slice thickness with subpixel precision. • The method preserves surface topography. • Quantitative 3D microstructural analysis of materials with open porosity.

  20. Topological code Autotune

    CERN Document Server

    Fowler, Austin G; McInnes, Angus L; Rabbani, Alimohammad

    2012-01-01

    Tailoring a fault-tolerant quantum error correction scheme to a specific physical architecture can be a laborious task. We describe a tool Autotune capable of analyzing and optimizing the classical processing for an arbitrary 2-D qubit architecture making use of arbitrary circuits implementing either the surface code or progressively generated slices of a 3-D topological cluster state with arbitrary stochastic error models for each quantum gate. Autotune is designed to facilitate precise study of the performance of real hardware running topological quantum error correction.

  1. Electronic structure studies of topological materials

    Science.gov (United States)

    Zhou, Shuyun

    Three-dimensional (3D) Dirac fermions are a new class of topological quantum materials. In 3D Dirac semimetals, the conduction and valence bands touch each other at discrete points in the momentum space and show linear dispersions along all momentum directions, forming 3D Dirac cones which are protected by the crystal symmetry. Here I will present our recent studies of the electronic structures of novel materials which host 3D Dirac fermions by using angle-resolved photoemission spectroscopy.

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

    Science.gov (United States)

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

    2013-09-01

    Cities and urban areas entities such as building structures are becoming more complex as the modern human civilizations continue to evolve. The ability to plan and manage every territory especially the urban areas is very important to every government in the world. Planning and managing cities and urban areas based on printed maps and 2D data are getting insufficient and inefficient to cope with the complexity of the new developments in big cities. The emergence of 3D city models have boosted the efficiency in analysing and managing urban areas as the 3D data are proven to represent the real world object more accurately. It has since been adopted as the new trend in buildings and urban management and planning applications. Nowadays, many countries around the world have been generating virtual 3D representation of their major cities. The growing interest in improving the usability of 3D city models has resulted in the development of various tools for analysis based on the 3D city models. Today, 3D city models are generated for various purposes such as for tourism, location-based services, disaster management and urban planning. Meanwhile, modelling 3D objects are getting easier with the emergence of the user-friendly tools for 3D modelling available in the market. Generating 3D buildings with high accuracy also has become easier with the availability of airborne Lidar and terrestrial laser scanning equipments. The availability and accessibility to this technology makes it more sensible to analyse buildings in urban areas using 3D data as it accurately represent the real world objects. The Open Geospatial Consortium (OGC) has accepted CityGML specifications as one of the international standards for representing and exchanging spatial data, making it easier to visualize, store and manage 3D city models data efficiently. CityGML able to represents the semantics, geometry, topology and appearance of 3D city models in five well-defined Level-of-Details (LoD), namely LoD0

  3. 3D RECORDING OF A 19-CENTURY OB RIVER SHIP

    Directory of Open Access Journals (Sweden)

    A. A. Pushkarev

    2016-06-01

    Full Text Available A 3D recording of a 19-century wooden ship discovered on the bank of the river Ob (Western Siberia was performed in autumn 2015. The archaeologized ship was partly under water, partly lying ashore, buried under fluvial deposits. The 3D recording was performed in October, when the water level was at its lowest after clearing the area around the ship. A 3D recording at the place of discovery was required as part of the ship museumification and reconstruction project. The works performed were primarily aimed at preserving as much information about the object as possible. Given the location and peculiar features of the object, a combination of close-range photogrammetry and aerial photography was considered to be the best possible solution for creating a high-quality 3D model. The dismantled ship was delivered to Nizhnevartovsk Museum of Local History in October 2015. The ship is going to be reassembled using the created 3D model to be exhibited in the museum. The resulting models are also going to be used to make a virtual 3D reconstruction of the ship in the future. We shot a stereoscopic video for Nizhnevartovsk Museum of Local History to let visitors see the place of discovery and explore the ship in greater details. Besides, 3D printing allowed for creating a miniature of the ship, which is also going to be included in the exposition devoted to this unique discovery.

  4. Adaptive interrogation for 3D-PIV

    Science.gov (United States)

    Novara, Matteo; Ianiro, Andrea; Scarano, Fulvio

    2013-02-01

    A method to adapt the shape and orientation of interrogation volumes for 3D-PIV motion analysis is introduced, aimed to increase the local spatial resolution. The main application of this approach is the detailed analysis of complex 3D and vortex-dominated flows that exhibit high vorticity in confined regions like shear layers and vortex filaments. The adaptive criterion is based on the analysis of the components of the local velocity gradient tensor, which returns the level of anisotropy of velocity spatial fluctuations. The principle to increase the local spatial resolution is based on the deformation of spherical isotropic interrogation regions, obtained by means of Gaussian weighting, into ellipsoids, with free choice of the principal axes and their directions. The interrogation region is contracted in the direction of the maximum velocity variation and elongated in the minimum one in order to maintain a constant interrogation volume. The adaptivity technique for three-dimensional PIV data takes advantage of the 3D topology of the flow, allowing increasing the spatial resolution not only in the case of shear layers, but also for vortex filaments, which is not possible for two-dimensional measurement in the plane normal to the vortex axis. The definition of the ellipsoidal interrogation region semi-axes is based on the singular values and singular directions of the local velocity gradient tensor as obtained by the singular values decomposition technique (SVD). The working principle is verified making use of numerical simulations of a shear layer and of a vortex filament. The application of the technique to data from a Tomo-PIV experiment conducted on a round jet, shows that the resolution of the shear layer at the jet exit can be considerably improved and an increase of about 25% in the vorticity peak is attained when the adaptive approach is applied. On the other hand, the peak vorticity description in the core of vortex rings is only slightly improved with

  5. Interactive 3D Mars Visualization

    Science.gov (United States)

    Powell, Mark W.

    2012-01-01

    The Interactive 3D Mars Visualization system provides high-performance, immersive visualization of satellite and surface vehicle imagery of Mars. The software can be used in mission operations to provide the most accurate position information for the Mars rovers to date. When integrated into the mission data pipeline, this system allows mission planners to view the location of the rover on Mars to 0.01-meter accuracy with respect to satellite imagery, with dynamic updates to incorporate the latest position information. Given this information so early in the planning process, rover drivers are able to plan more accurate drive activities for the rover than ever before, increasing the execution of science activities significantly. Scientifically, this 3D mapping information puts all of the science analyses to date into geologic context on a daily basis instead of weeks or months, as was the norm prior to this contribution. This allows the science planners to judge the efficacy of their previously executed science observations much more efficiently, and achieve greater science return as a result. The Interactive 3D Mars surface view is a Mars terrain browsing software interface that encompasses the entire region of exploration for a Mars surface exploration mission. The view is interactive, allowing the user to pan in any direction by clicking and dragging, or to zoom in or out by scrolling the mouse or touchpad. This set currently includes tools for selecting a point of interest, and a ruler tool for displaying the distance between and positions of two points of interest. The mapping information can be harvested and shared through ubiquitous online mapping tools like Google Mars, NASA WorldWind, and Worldwide Telescope.

  6. Wireless 3D Chocolate Printer

    Directory of Open Access Journals (Sweden)

    FROILAN G. DESTREZA

    2014-02-01

    Full Text Available This study is for the BSHRM Students of Batangas State University (BatStateU ARASOF for the researchers believe that the Wireless 3D Chocolate Printer would be helpful in their degree program especially on making creative, artistic, personalized and decorative chocolate designs. The researchers used the Prototyping model as procedural method for the successful development and implementation of the hardware and software. This method has five phases which are the following: quick plan, quick design, prototype construction, delivery and feedback and communication. This study was evaluated by the BSHRM Students and the assessment of the respondents regarding the software and hardware application are all excellent in terms of Accuracy, Effecitveness, Efficiency, Maintainability, Reliability and User-friendliness. Also, the overall level of acceptability of the design project as evaluated by the respondents is excellent. With regard to the observation about the best raw material to use in 3D printing, the chocolate is good to use as the printed material is slightly distorted,durable and very easy to prepare; the icing is also good to use as the printed material is not distorted and is very durable but consumes time to prepare; the flour is not good as the printed material is distorted, not durable but it is easy to prepare. The computation of the economic viability level of 3d printer with reference to ROI is 37.14%. The recommendation of the researchers in the design project are as follows: adding a cooling system so that the raw material will be more durable, development of a more simplified version and improving the extrusion process wherein the user do not need to stop the printing process just to replace the empty syringe with a new one.

  7. Virtual 3-D Facial Reconstruction

    Directory of Open Access Journals (Sweden)

    Martin Paul Evison

    2000-06-01

    Full Text Available Facial reconstructions in archaeology allow empathy with people who lived in the past and enjoy considerable popularity with the public. It is a common misconception that facial reconstruction will produce an exact likeness; a resemblance is the best that can be hoped for. Research at Sheffield University is aimed at the development of a computer system for facial reconstruction that will be accurate, rapid, repeatable, accessible and flexible. This research is described and prototypical 3-D facial reconstructions are presented. Interpolation models simulating obesity, ageing and ethnic affiliation are also described. Some strengths and weaknesses in the models, and their potential for application in archaeology are discussed.

  8. How 3-D Movies Work

    Institute of Scientific and Technical Information of China (English)

    吕铁雄

    2011-01-01

    难度:★★★★☆词数:450 建议阅读时间:8分钟 Most people see out of two eyes. This is a basic fact of humanity,but it’s what makes possible the illusion of depth(纵深幻觉) that 3-D movies create. Human eyes are spaced about two inches apart, meaning that each eye gives the brain a slightly different perspective(透视感)on the same object. The brain then uses this variance to quickly determine an object’s distance.

  9. Gis-Based Smart Cartography Using 3d Modeling

    Science.gov (United States)

    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.

  10. 3D Image Fusion to Localise Intercostal Arteries During TEVAR.

    Science.gov (United States)

    Koutouzi, G; Sandström, C; Skoog, P; Roos, H; Falkenberg, M

    2017-01-01

    Preservation of intercostal arteries during thoracic aortic procedures reduces the risk of post-operative paraparesis. The origins of the intercostal arteries are visible on pre-operative computed tomography angiography (CTA), but rarely on intra-operative angiography. The purpose of this report is to suggest an image fusion technique for intra-operative localisation of the intercostal arteries during thoracic endovascular repair (TEVAR). The ostia of the intercostal arteries are identified and manually marked with rings on the pre-operative CTA. The optimal distal landing site in the descending aorta is determined and marked, allowing enough length for an adequate seal and attachment without covering more intercostal arteries than necessary. After 3D/3D fusion of the pre-operative CTA with an intra-operative cone-beam CT (CBCT), the markings are overlaid on the live fluoroscopy screen for guidance. The accuracy of the overlay is confirmed with digital subtraction angiography (DSA) and the overlay is adjusted when needed. Stent graft deployment is guided by the markings. The initial experience of this technique in seven patients is presented. 3D image fusion was feasible in all cases. Follow-up CTA after 1 month revealed that all intercostal arteries planned for preservation, were patent. None of the patients developed signs of spinal cord ischaemia. 3D image fusion can be used to localise the intercostal arteries during TEVAR. This may preserve some intercostal arteries and reduce the risk of post-operative spinal cord ischaemia.

  11. Positional Awareness Map 3D (PAM3D)

    Science.gov (United States)

    Hoffman, Monica; Allen, Earl L.; Yount, John W.; Norcross, April Louise

    2012-01-01

    The Western Aeronautical Test Range of the National Aeronautics and Space Administration s Dryden Flight Research Center needed to address the aging software and hardware of its current situational awareness display application, the Global Real-Time Interactive Map (GRIM). GRIM was initially developed in the late 1980s and executes on older PC architectures using a Linux operating system that is no longer supported. Additionally, the software is difficult to maintain due to its complexity and loss of developer knowledge. It was decided that a replacement application must be developed or acquired in the near future. The replacement must provide the functionality of the original system, the ability to monitor test flight vehicles in real-time, and add improvements such as high resolution imagery and true 3-dimensional capability. This paper will discuss the process of determining the best approach to replace GRIM, and the functionality and capabilities of the first release of the Positional Awareness Map 3D.

  12. 3D Printable Graphene Composite

    Science.gov (United States)

    Wei, Xiaojun; Li, Dong; Jiang, Wei; Gu, Zheming; Wang, Xiaojuan; Zhang, Zengxing; Sun, Zhengzong

    2015-07-01

    In human being’s history, both the Iron Age and Silicon Age thrived after a matured massive processing technology was developed. Graphene is the most recent superior material which could potentially initialize another new material Age. However, while being exploited to its full extent, conventional processing methods fail to provide a link to today’s personalization tide. New technology should be ushered in. Three-dimensional (3D) printing fills the missing linkage between graphene materials and the digital mainstream. Their alliance could generate additional stream to push the graphene revolution into a new phase. Here we demonstrate for the first time, a graphene composite, with a graphene loading up to 5.6 wt%, can be 3D printable into computer-designed models. The composite’s linear thermal coefficient is below 75 ppm·°C-1 from room temperature to its glass transition temperature (Tg), which is crucial to build minute thermal stress during the printing process.

  13. 3D medical thermography device

    Science.gov (United States)

    Moghadam, Peyman

    2015-05-01

    In this paper, a novel handheld 3D medical thermography system is introduced. The proposed system consists of a thermal-infrared camera, a color camera and a depth camera rigidly attached in close proximity and mounted on an ergonomic handle. As a practitioner holding the device smoothly moves it around the human body parts, the proposed system generates and builds up a precise 3D thermogram model by incorporating information from each new measurement in real-time. The data is acquired in motion, thus it provides multiple points of view. When processed, these multiple points of view are adaptively combined by taking into account the reliability of each individual measurement which can vary due to a variety of factors such as angle of incidence, distance between the device and the subject and environmental sensor data or other factors influencing a confidence of the thermal-infrared data when captured. Finally, several case studies are presented to support the usability and performance of the proposed system.

  14. 3D Printed Bionic Ears

    Science.gov (United States)

    Mannoor, Manu S.; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A.; Soboyejo, Winston O.; Verma, Naveen; Gracias, David H.; McAlpine, Michael C.

    2013-01-01

    The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the precise anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing. PMID:23635097

  15. 3D printed bionic ears.

    Science.gov (United States)

    Mannoor, Manu S; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A; Soboyejo, Winston O; Verma, Naveen; Gracias, David H; McAlpine, Michael C

    2013-06-12

    The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing.

  16. Creating physical 3D stereolithograph models of brain and skull.

    Directory of Open Access Journals (Sweden)

    Daniel J Kelley

    Full Text Available The human brain and skull are three dimensional (3D anatomical structures with complex surfaces. However, medical images are often two dimensional (2D and provide incomplete visualization of structural morphology. To overcome this loss in dimension, we developed and validated a freely available, semi-automated pathway to build 3D virtual reality (VR and hand-held, stereolithograph models. To evaluate whether surface visualization in 3D was more informative than in 2D, undergraduate students (n = 50 used the Gillespie scale to rate 3D VR and physical models of both a living patient-volunteer's brain and the skull of Phineas Gage, a historically famous railroad worker whose misfortune with a projectile tamping iron provided the first evidence of a structure-function relationship in brain. Using our processing pathway, we successfully fabricated human brain and skull replicas and validated that the stereolithograph model preserved the scale of the VR model. Based on the Gillespie ratings, students indicated that the biological utility and quality of visual information at the surface of VR and stereolithograph models were greater than the 2D images from which they were derived. The method we developed is useful to create VR and stereolithograph 3D models from medical images and can be used to model hard or soft tissue in living or preserved specimens. Compared to 2D images, VR and stereolithograph models provide an extra dimension that enhances both the quality of visual information and utility of surface visualization in neuroscience and medicine.

  17. Probe into Key Techniques of Regional-Oriented 3D GIS On the key techniques of 3D GIS used for regional Geological Information System

    Institute of Scientific and Technical Information of China (English)

    ZHU Liang-feng; WU Xin-cai; PAN Xin

    2005-01-01

    Regional Geological Information System combines the multi-dimensional and dynamic spatial information into an integrated spatial information system. 3D geological modeling and its preprocessing or post-processing are the most difficult problems for constructing the system. Based on the current 3D GIS technique, some basic problems in establishing the system are discussed in this paper, including 3D spatial data model, 3D geological modeling, and visualization of 3D geological data. A kind of 3D vector data model based on boundary representation for geological object and its topology was developed in order to model and visualize complex geological structures. In addition, some key techniques are pointed out for further study.

  18. 3D biometrics systems and applications

    CERN Document Server

    Zhang, David

    2013-01-01

    Includes discussions on popular 3D imaging technologies, combines them with biometric applications, and then presents real 3D biometric systems Introduces many efficient 3D feature extraction, matching, and fusion algorithms Techniques presented have been supported by experimental results using various 3D biometric classifications

  19. Conducting Polymer 3D Microelectrodes

    Directory of Open Access Journals (Sweden)

    Jenny Emnéus

    2010-12-01

    Full Text Available Conducting polymer 3D microelectrodes have been fabricated for possible future neurological applications. A combination of micro-fabrication techniques and chemical polymerization methods has been used to create pillar electrodes in polyaniline and polypyrrole. The thin polymer films obtained showed uniformity and good adhesion to both horizontal and vertical surfaces. Electrodes in combination with metal/conducting polymer materials have been characterized by cyclic voltammetry and the presence of the conducting polymer film has shown to increase the electrochemical activity when compared with electrodes coated with only metal. An electrochemical characterization of gold/polypyrrole electrodes showed exceptional electrochemical behavior and activity. PC12 cells were finally cultured on the investigated materials as a preliminary biocompatibility assessment. These results show that the described electrodes are possibly suitable for future in-vitro neurological measurements.

  20. A COMPARISON OF EXISTING ALGORITHMS FOR 3D TREE RECONSTRUCTION

    Directory of Open Access Journals (Sweden)

    E. Bournez

    2017-02-01

    Full Text Available 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.

  1. Filling gaps in cultural heritage documentation by 3D photography

    Science.gov (United States)

    Schuhr, W.; Lee, J. D.

    2015-08-01

    This contribution promotes 3D photography as an important tool to obtain objective object information. Keeping mainly in mind World Heritage documentation as well as Heritage protection, it is another intention of this paper, to stimulate the interest in applications of 3D photography for professionals as well as for amateurs. In addition this is also an activity report of the international CIPA task group 3. The main part of this paper starts with "Digging the treasure of existing international 3D photography". This does not only belong to tangible but also to intangible Cultural Heritage. 3D photography clearly supports the recording, the visualization, the preservation and the restoration of architectural and archaeological objects. Therefore the use of 3D photography in C.H. should increase on an international level. The presented samples in 3D represent a voluminous, almost partly "forgotten treasure" of international archives for 3D photography. The next chapter is on "Promoting new 3D photography in Cultural Heritage". Though 3D photographs are a well-established basic photographic and photogrammetric tool, even suited to provide "near real" documentation, they are still a matter of research and improvement. Beside the use of 3D cameras even single lenses cameras are very much suited for photographic 3D documentation purposes in Cultural Heritage. Currently at the Faculty of Civil Engineering of the University of Applied Sciences Magdeburg-Stendal, low altitude aerial photography is exposed from a maximum height of 13m, using a hand hold carbon telescope rod. The use of this "huge selfie stick" is also an (international) recommendation, to expose high resolution 3D photography of monuments under expedition conditions. In addition to the carbon rod recently a captive balloon and a hexacopter UAV- platform is in use, mainly to take better synoptically (extremely low altitude, ground truth) aerial photography. Additional experiments with respect to "easy

  2. Supernova Remnant in 3-D

    Science.gov (United States)

    2009-01-01

    of the wavelength shift is related to the speed of motion, one can determine how fast the debris are moving in either direction. Because Cas A is the result of an explosion, the stellar debris is expanding radially outwards from the explosion center. Using simple geometry, the scientists were able to construct a 3-D model using all of this information. A program called 3-D Slicer modified for astronomical use by the Astronomical Medicine Project at Harvard University in Cambridge, Mass. was used to display and manipulate the 3-D model. Commercial software was then used to create the 3-D fly-through. The blue filaments defining the blast wave were not mapped using the Doppler effect because they emit a different kind of light synchrotron radiation that does not emit light at discrete wavelengths, but rather in a broad continuum. The blue filaments are only a representation of the actual filaments observed at the blast wave. This visualization shows that there are two main components to this supernova remnant: a spherical component in the outer parts of the remnant and a flattened (disk-like) component in the inner region. The spherical component consists of the outer layer of the star that exploded, probably made of helium and carbon. These layers drove a spherical blast wave into the diffuse gas surrounding the star. The flattened component that astronomers were unable to map into 3-D prior to these Spitzer observations consists of the inner layers of the star. It is made from various heavier elements, not all shown in the visualization, such as oxygen, neon, silicon, sulphur, argon and iron. High-velocity plumes, or jets, of this material are shooting out from the explosion in the plane of the disk-like component mentioned above. Plumes of silicon appear in the northeast and southwest, while those of iron are seen in the southeast and north. These jets were already known and Doppler velocity measurements have been made for these structures, but their orientation and

  3. 3D Printing of Graphene Aerogels.

    Science.gov (United States)

    Zhang, Qiangqiang; Zhang, Feng; Medarametla, Sai Pradeep; Li, Hui; Zhou, Chi; Lin, Dong

    2016-04-01

    3D printing of a graphene aerogel with true 3D overhang structures is highlighted. The aerogel is fabricated by combining drop-on-demand 3D printing and freeze casting. The water-based GO ink is ejected and freeze-cast into designed 3D structures. The lightweight (<10 mg cm(-3) ) 3D printed graphene aerogel presents superelastic and high electrical conduction.

  4. A 3D printed electromagnetic nonlinear vibration energy harvester

    Science.gov (United States)

    Constantinou, P.; Roy, S.

    2016-09-01

    A 3D printed electromagnetic vibration energy harvester is presented. The motion of the device is in-plane with the excitation vibrations, and this is enabled through the exploitation of a leaf isosceles trapezoidal flexural pivot topology. This topology is ideally suited for systems requiring restricted out-of-plane motion and benefits from being fabricated monolithically. This is achieved by 3D printing the topology with materials having a low flexural modulus. The presented system has a nonlinear softening spring response, as a result of designed magnetic force interactions. A discussion of fatigue performance is presented and it is suggested that whilst fabricating, the raster of the suspension element is printed perpendicular to the flexural direction and that the experienced stress is as low as possible during operation, to ensure longevity. A demonstrated power of ˜25 μW at 0.1 g is achieved and 2.9 mW is demonstrated at 1 g. The corresponding bandwidths reach up-to 4.5 Hz. The system’s corresponding power density of ˜0.48 mW cm-3 and normalised power integral density of 11.9 kg m-3 (at 1 g) are comparable to other in-plane systems found in the literature.

  5. How little do we need for 3-D shape perception?

    Science.gov (United States)

    Nandakumar, Chetan; Torralba, Antonio; Malik, Jitendra

    2011-01-01

    How little do we need to perceive 3-D shape in monocular natural images? The shape-from-texture and shape-from-shading perspectives would motivate that 3-D perception vanishes once low-level cues are disrupted. Is this the case in human vision? Or can top-down influences salvage the percept? In this study we probe this question by employing a gauge-figure paradigm similar to that used by Koenderink et al (1992, Perception & Psychophysics 52 487-496). Subjects were presented degraded natural images and instructed to make local assessments of slant and tilt at various locations thereby quantifying their internal 3-D percept. Analysis of subjects' responses reveals recognition to be a significant influence thereby allowing subjects to perceive 3-D shape at high levels of degradation. Specifically, we identify the 'medium-blur' condition, images approximately 32 pixels on a side, to be the limit for accurate 3-D shape perception. In addition, we find that degradation affects the perceived slant of point-estimates making images look flatter as degradation increases. A subsequent condition that eliminates texture and shading but preserves contour and recognition reveals how bottom-up and top-down cues can combine for accurate 3-D shape perception.

  6. Dimensional Hierarchy of Fermionic Interacting Topological Phases

    Science.gov (United States)

    Queiroz, Raquel; Khalaf, Eslam; Stern, Ady

    2016-11-01

    We present a dimensional reduction argument to derive the classification reduction of fermionic symmetry protected topological phases in the presence of interactions. The dimensional reduction proceeds by relating the topological character of a d -dimensional system to the number of zero-energy bound states localized at zero-dimensional topological defects present at its surface. This correspondence leads to a general condition for symmetry preserving interactions that render the system topologically trivial, and allows us to explicitly write a quartic interaction to this end. Our reduction shows that all phases with topological invariant smaller than n are topologically distinct, thereby reducing the noninteracting Z classification to Zn.

  7. Dimensional Hierarchy of Fermionic Interacting Topological Phases.

    Science.gov (United States)

    Queiroz, Raquel; Khalaf, Eslam; Stern, Ady

    2016-11-11

    We present a dimensional reduction argument to derive the classification reduction of fermionic symmetry protected topological phases in the presence of interactions. The dimensional reduction proceeds by relating the topological character of a d-dimensional system to the number of zero-energy bound states localized at zero-dimensional topological defects present at its surface. This correspondence leads to a general condition for symmetry preserving interactions that render the system topologically trivial, and allows us to explicitly write a quartic interaction to this end. Our reduction shows that all phases with topological invariant smaller than n are topologically distinct, thereby reducing the noninteracting Z classification to Z_{n}.

  8. Rendering the Topological Spines

    Energy Technology Data Exchange (ETDEWEB)

    Nieves-Rivera, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-05-05

    Many tools to analyze and represent high dimensional data already exits yet most of them are not flexible, informative and intuitive enough to help the scientists make the corresponding analysis and predictions, understand the structure and complexity of scientific data, get a complete picture of it and explore a greater number of hypotheses. With this in mind, N-Dimensional Data Analysis and Visualization (ND²AV) is being developed to serve as an interactive visual analysis platform with the purpose of coupling together a number of these existing tools that range from statistics, machine learning, and data mining, with new techniques, in particular with new visualization approaches. My task is to create the rendering and implementation of a new concept called topological spines in order to extend ND²AV's scope. Other existing visualization tools create a representation preserving either the topological properties or the structural (geometric) ones because it is challenging to preserve them both simultaneously. Overcoming such challenge by creating a balance in between them, the topological spines are introduced as a new approach that aims to preserve them both. Its render using OpenGL and C++ and is currently being tested to further on be implemented on ND²AV. In this paper I will present what are the Topological Spines and how they are rendered.

  9. The 3D Flow Field Around an Embedded Planet

    CERN Document Server

    Fung, Jeffrey; Wu, Yanqin

    2015-01-01

    Understanding the 3D flow topology around a planet embedded in its natal disk is crucial to the study of planet formation. 3D modifications to the well-studied 2D flow topology have the potential to resolve longstanding problems in both planet migration and accretion. We present a detailed analysis of the 3D isothermal flow field around a 5 Earth-mass planet on a fixed circular orbit, simulated using our high-resolution multi-GPU hydrodynamics code PEnGUIn. We show that, overall, the horseshoe region has a columnar structure extending vertically much beyond the Hill sphere of the planet. This columnar structure is only broken for some of the widest horseshoe streamlines, along which high altitude fluid descends and converges rapidly toward the planet, enters its Bondi sphere, performs one horseshoe turn, and exits radially in the midplane. A portion of this flow gathers enough speed to exit the horseshoe region altogether. We call this newly identified feature the "transient" horseshoe flow. As the flow conti...

  10. 3D multiplexed immunoplasmonics microscopy

    Science.gov (United States)

    Bergeron, Éric; Patskovsky, Sergiy; Rioux, David; Meunier, Michel

    2016-07-01

    Selective labelling, identification and spatial distribution of cell surface biomarkers can provide important clinical information, such as distinction between healthy and diseased cells, evolution of a disease and selection of the optimal patient-specific treatment. Immunofluorescence is the gold standard for efficient detection of biomarkers expressed by cells. However, antibodies (Abs) conjugated to fluorescent dyes remain limited by their photobleaching, high sensitivity to the environment, low light intensity, and wide absorption and emission spectra. Immunoplasmonics is a novel microscopy method based on the visualization of Abs-functionalized plasmonic nanoparticles (fNPs) targeting cell surface biomarkers. Tunable fNPs should provide higher multiplexing capacity than immunofluorescence since NPs are photostable over time, strongly scatter light at their plasmon peak wavelengths and can be easily functionalized. In this article, we experimentally demonstrate accurate multiplexed detection based on the immunoplasmonics approach. First, we achieve the selective labelling of three targeted cell surface biomarkers (cluster of differentiation 44 (CD44), epidermal growth factor receptor (EGFR) and voltage-gated K+ channel subunit KV1.1) on human cancer CD44+ EGFR+ KV1.1+ MDA-MB-231 cells and reference CD44- EGFR- KV1.1+ 661W cells. The labelling efficiency with three stable specific immunoplasmonics labels (functionalized silver nanospheres (CD44-AgNSs), gold (Au) NSs (EGFR-AuNSs) and Au nanorods (KV1.1-AuNRs)) detected by reflected light microscopy (RLM) is similar to the one with immunofluorescence. Second, we introduce an improved method for 3D localization and spectral identification of fNPs based on fast z-scanning by RLM with three spectral filters corresponding to the plasmon peak wavelengths of the immunoplasmonics labels in the cellular environment (500 nm for 80 nm AgNSs, 580 nm for 100 nm AuNSs and 700 nm for 40 nm × 92 nm AuNRs). Third, the developed

  11. The Kodama state for topological quantum field theory beyond instantons

    CERN Document Server

    Cartas-Fuentevilla, R

    2005-01-01

    Constructing a symplectic structure that preserves the ordinary symmetries and the topological invariance for topological Yang-Mills theory, it is shown that the Kodama (Chern-Simons) state traditionally associated with a topological phase of unbroken diffeomorphism invariance for instantons, exists actually for the complete topological sector of the theory. The case of gravity is briefly discussed.

  12. Algebraic Topology

    OpenAIRE

    2013-01-01

    The chapter provides an introduction to the basic concepts of Algebraic Topology with an emphasis on motivation from applications in the physical sciences. It finishes with a brief review of computational work in algebraic topology, including persistent homology.

  13. QCD as topologically ordered system

    CERN Document Server

    Zhitnitsky, Ariel R

    2013-01-01

    We argue that QCD belongs to a topologically ordered phase similar to many well-known condensed matter systems with a gap such as topological insulators or superconductors. Our arguments are based on analysis of the so-called ``deformed QCD" which is a weakly coupled gauge theory, but nevertheless preserves all crucial elements of strongly interacting QCD, including confinement, nontrivial $\\theta$ dependence, degeneracy of the topological sectors, etc. Specifically, we construct the so-called topological ``BF" action which reproduces the well known infrared features of the theory such as non-dispersive contribution to the topological susceptibility which can not be associated with any propagating degrees of freedom. Furthermore, we interpret the well known resolution of the celebrated $U(1)_A$ problem when would be $\\eta'$ Goldstone boson generates its mass as a result of mixing of the Goldstone field with a topological auxiliary field characterizing the system. We identify the non-propagating auxiliary topo...

  14. Phase field model for optimization of multi-material structural topology in two and three dimensions

    Science.gov (United States)

    Zhou, Shiwei

    The Optimization of Structural Topology (OST) is a breakthrough in product design because it can optimize size, shape and topology synchronously under different physical constraints. It has promising applications in industry ranging from automobile and aerospace engineering to micro electromechanical system. This dissertation first substitutes the nonlinear diffusion method for filter process in the optimization of structural topology. Filtering has been a major technique used in a homogenization-based method for topology optimization of structures. It plays a key role in regularizing the basic problem into a well-behaved setting. But it has a drawback of smoothing effect around the boundary of material domain. A diffusion technique is presented here as a variational approach to the regularization of the topology optimization problem. A nonlinear or anisotropic diffusion process not only leads to a suitable problem regularization but also exhibits strong "edge"-preserving characteristics. Thus, it shows that the use of the nonlinear diffusions brings desirable effects of boundary preservation and even enhancement of lower-dimensional features such as flow-like structures. The proposed diffusion techniques have a close relationship with the diffusion methods and the phase-field methods of the fields of materials and digital image processing. Then this dissertation introduces a gradient flow in the norm of H-1 for the problem of multi-material structural topology optimization in 2/3D with a generalized Cahn-Hilliard (C-H) model with elasticity. Unlike the traditional C-H model applied to spinodal separation which only has bulk energy and interface energy, the generalized model couples the macroscopic elastic energy (mean compliance) into the total free energy. As a result, the grain morphology is not random islands or zigzag web-like objects but regular truss or bar structure. Although disturbed by elastic energy, the C-H system still keeps its two most important

  15. Crowdsourcing Based 3d Modeling

    Science.gov (United States)

    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.

  16. Surface topography study of prepared 3D printed moulds via 3D printer for silicone elastomer based nasal prosthesis

    Science.gov (United States)

    Abdullah, Abdul Manaf; Din, Tengku Noor Daimah Tengku; Mohamad, Dasmawati; Rahim, Tuan Noraihan Azila Tuan; Akil, Hazizan Md; Rajion, Zainul Ahmad

    2016-12-01

    Conventional prosthesis fabrication is highly depends on the hand creativity of laboratory technologist. The development in 3D printing technology offers a great help in fabricating affordable and fast yet esthetically acceptable prostheses. This study was conducted to discover the potential of 3D printed moulds for indirect silicone elastomer based nasal prosthesis fabrication. Moulds were designed using computer aided design (CAD) software (Solidworks, USA) and converted into the standard tessellation language (STL) file. Three moulds with layer thickness of 0.1, 0.2 and 0.3mm were printed utilizing polymer filament based 3D printer (Makerbot Replicator 2X, Makerbot, USA). Another one mould was printed utilizing liquid resin based 3D printer (Objet 30 Scholar, Stratasys, USA) as control. The printed moulds were then used to fabricate maxillofacial silicone specimens (n=10)/mould. Surface profilometer (Surfcom Flex, Accretech, Japan), digital microscope (KH77000, Hirox, USA) and scanning electron microscope (Quanta FEG 450, Fei, USA) were used to measure the surface roughness as well as the topological properties of fabricated silicone. Statistical analysis of One-Way ANOVA was employed to compare the surface roughness of the fabricated silicone elastomer. Result obtained demonstrated significant differences in surface roughness of the fabricated silicone (p<0.01). Further post hoc analysis also revealed significant differences in silicone fabricated using different 3D printed moulds (p<0.01). A 3D printed mould was successfully prepared and characterized. With surface topography that could be enhanced, inexpensive and rapid mould fabrication techniques, polymer filament based 3D printer is potential for indirect silicone elastomer based nasal prosthesis fabrication.

  17. Watermarking Algorithms for 3D NURBS Graphic Data

    Directory of Open Access Journals (Sweden)

    Jae Jun Lee

    2004-10-01

    Full Text Available Two watermarking algorithms for 3D nonuniform rational B-spline (NURBS graphic data are proposed: one is appropriate for the steganography, and the other for watermarking. Instead of directly embedding data into the parameters of NURBS, the proposed algorithms embed data into the 2D virtual images extracted by parameter sampling of 3D model. As a result, the proposed steganography algorithm can embed information into more places of the surface than the conventional algorithm, while preserving the data size of the model. Also, any existing 2D watermarking technique can be used for the watermarking of 3D NURBS surfaces. From the experiment, it is found that the algorithm for the watermarking is robust to the attacks on weights, control points, and knots. It is also found to be robust to the remodeling of NURBS models.

  18. The Etruscans in 3D: From Space to Underground

    Directory of Open Access Journals (Sweden)

    Fabio Remondino

    2011-12-01

    Full Text Available eomatics and Geoinformatics deal with spatial and geographic information, 3D surveying and modeling as well as information science infrastructures. Geomatics and Geoinformatics are thus involved in cartography, mapping, photogrammetry, remote sensing, laser scanning, Geographic Information Systems (GIS, Global Navigation Satellite Systems (GNSS, geo-visualisation, geospatial data analysis and Cultural Heritage documentation. In particular the Cultural Heritage field can largely benefit from different Information and Communication Technologies (ICT tools to make digital heritage information more informative for documentation and conservation issues, archaeological analyses or virtual museums. This work presents the 3D surveying and modeling of different Etruscan heritage sites with their underground frescoed tombs dating back to VII-IV century B.C.. The recorded and processed 3D data are used, beside digital conservation, preservation, transmission to future generations and studies purposes, to create digital contents for virtual visits, museum exhibitions, better access and communication of the heritage information, etc.

  19. Topology optimised wavelength dependent splitters

    DEFF Research Database (Denmark)

    Hede, K. K.; Burgos Leon, J.; Frandsen, Lars Hagedorn

    A photonic crystal wavelength dependent splitter has been constructed by utilising topology optimisation1. The splitter has been fabricated in a silicon-on-insulator material (Fig. 1). The topology optimised wavelength dependent splitter demonstrates promising 3D FDTD simulation results....... This complex photonic crystal structure is very sensitive against small fabrication variations from the expected topology optimised design. A wavelength dependent splitter is an important basic building block for high-performance nanophotonic circuits. 1J. S. Jensen and O. Sigmund, App. Phys. Lett. 84, 2022...

  20. Topology optimised wavelength dependent splitters

    DEFF Research Database (Denmark)

    Hede, K. K.; Burgos Leon, J.; Frandsen, Lars Hagedorn;

    A photonic crystal wavelength dependent splitter has been constructed by utilising topology optimisation1. The splitter has been fabricated in a silicon-on-insulator material (Fig. 1). The topology optimised wavelength dependent splitter demonstrates promising 3D FDTD simulation results....... This complex photonic crystal structure is very sensitive against small fabrication variations from the expected topology optimised design. A wavelength dependent splitter is an important basic building block for high-performance nanophotonic circuits. 1J. S. Jensen and O. Sigmund, App. Phys. Lett. 84, 2022...

  1. Vrste i tehnike 3D modeliranja

    OpenAIRE

    Bernik, Andrija

    2010-01-01

    Proces stvaranja 3D stvarnih ili imaginarnih objekata naziva se 3D modeliranje. Razvoj računalne tehnologije omogućuje korisniku odabir raznih metoda i tehnika kako bi se postigla optimalna učinkovitost. Odabir je vezan za klasično 3D modeliranje ili 3D skeniranje pomoću specijaliziranih programskih i sklopovskih rješenja. 3D tehnikama modeliranja korisnik može izraditi 3D model na nekoliko načina: koristi poligone, krivulje ili hibrid dviju spomenutih tehnika pod nazivom subdivizijsko modeli...

  2. Kuvaus 3D-tulostamisesta hammastekniikassa

    OpenAIRE

    Munne, Mauri; Mustonen, Tuomas; Vähäjylkkä, Jaakko

    2013-01-01

    3D-tulostaminen kehittyy nopeasti ja yleistyy koko ajan. Tulostimien tarkkuuksien kehittyessä 3D-tulostus on ottamassa myös jalansijaa hammastekniikan alalta. Tämän opinnäytetyön tarkoituksena on kuvata 3D-tulostamisen tilaa hammastekniikassa. 3D-tulostaminen on Suomessa vielä melko harvinaista, joten opinnäytetyön tavoitteena on koota yhteen kaikki mahdollinen tieto liittyen 3D-tulostamiseen hammastekniikassa. Tavoitteena on myös 3D-tulostimen testaaminen käytännössä aina suun skannaami...

  3. 3D string theory and Umbral moonshine

    Science.gov (United States)

    Kachru, Shamit; Paquette, Natalie M.; Volpato, Roberto

    2017-10-01

    The simplest string theory compactifications to 3D with 16 supercharges—the heterotic string on T 7, and type II strings on K3 × T3 —are related by U-duality, and share a moduli space of vacua parametrized by O(8, 24;{{ Z}}) ~\\backslash ~O(8, 24)~ /~ (O(8) × O(24)) . One can think of this as the moduli space of even, self-dual 32-dimensional lattices with signature (8,24). At 24 special points in moduli space, the lattice splits as Γ8, 0 \\oplus Γ0, 24 . Γ0, 24 can be the Leech lattice or any of 23 Niemeier lattices, while Γ8, 0 is the E 8 root lattice. We show that starting from this observation, one can find a precise connection between the Umbral groups and type IIA string theory on K3. This may provide a natural physical starting point for understanding Mathieu and Umbral moonshine. The maximal unbroken subgroups of Umbral groups in 6D (or any other limit) are those obtained by starting at the associated Niemeier point and moving in moduli space while preserving the largest possible subgroup of the Umbral group. To illustrate the action of these symmetries on BPS states, we discuss the computation of certain protected four-derivative terms in the effective field theory, and recover facts about the spectrum and symmetry representations of 1/2-BPS states.

  4. 3D Modelling of Kizildag Monument

    Science.gov (United States)

    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

  5. Forward ramp in 3D

    Science.gov (United States)

    1997-01-01

    Mars Pathfinder's forward rover ramp can be seen successfully unfurled in this image, taken in stereo by the Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses are necessary to identify surface detail. This ramp was not used for the deployment of the microrover Sojourner, which occurred at the end of Sol 2. When this image was taken, Sojourner was still latched to one of the lander's petals, waiting for the command sequence that would execute its descent off of the lander's petal.The image helped Pathfinder scientists determine whether to deploy the rover using the forward or backward ramps and the nature of the first rover traverse. The metallic object at the lower left of the image is the lander's low-gain antenna. The square at the end of the ramp is one of the spacecraft's magnetic targets. Dust that accumulates on the magnetic targets will later be examined by Sojourner's Alpha Proton X-Ray Spectrometer instrument for chemical analysis. At right, a lander petal is visible.The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  6. 3D RECORDING FOR 2D DELIVERING – THE EMPLOYMENT OF 3D MODELS FOR STUDIES AND ANALYSES –

    Directory of Open Access Journals (Sweden)

    A. Rizzi

    2012-09-01

    Full Text Available In the last years, thanks to the advances of surveying sensors and techniques, many heritage sites could be accurately replicated in digital form with very detailed and impressive results. The actual limits are mainly related to hardware capabilities, computation time and low performance of personal computer. Often, the produced models are not visible on a normal computer and the only solution to easily visualized them is offline using rendered videos. This kind of 3D representations is useful for digital conservation, divulgation purposes or virtual tourism where people can visit places otherwise closed for preservation or security reasons. But many more potentialities and possible applications are available using a 3D model. The problem is the ability to handle 3D data as without adequate knowledge this information is reduced to standard 2D data. This article presents some surveying and 3D modeling experiences within the APSAT project ("Ambiente e Paesaggi dei Siti d’Altura Trentini", i.e. Environment and Landscapes of Upland Sites in Trentino. APSAT is a multidisciplinary project funded by the Autonomous Province of Trento (Italy with the aim documenting, surveying, studying, analysing and preserving mountainous and hill-top heritage sites located in the region. The project focuses on theoretical, methodological and technological aspects of the archaeological investigation of mountain landscape, considered as the product of sequences of settlements, parcelling-outs, communication networks, resources, and symbolic places. The mountain environment preserves better than others the traces of hunting and gathering, breeding, agricultural, metallurgical, symbolic activities characterised by different lengths and environmental impacts, from Prehistory to the Modern Period. Therefore the correct surveying and documentation of this heritage sites and material is very important. Within the project, the 3DOM unit of FBK is delivering all the surveying

  7. Sliding Adjustment for 3D Video Representation

    Directory of Open Access Journals (Sweden)

    Galpin Franck

    2002-01-01

    Full Text Available This paper deals with video coding of static scenes viewed by a moving camera. We propose an automatic way to encode such video sequences using several 3D models. Contrary to prior art in model-based coding where 3D models have to be known, the 3D models are automatically computed from the original video sequence. We show that several independent 3D models provide the same functionalities as one single 3D model, and avoid some drawbacks of the previous approaches. To achieve this goal we propose a novel algorithm of sliding adjustment, which ensures consistency of successive 3D models. The paper presents a method to automatically extract the set of 3D models and associate camera positions. The obtained representation can be used for reconstructing the original sequence, or virtual ones. It also enables 3D functionalities such as synthetic object insertion, lightning modification, or stereoscopic visualization. Results on real video sequences are presented.

  8. An interactive multiview 3D display system

    Science.gov (United States)

    Zhang, Zhaoxing; Geng, Zheng; Zhang, Mei; Dong, Hui

    2013-03-01

    The progresses in 3D display systems and user interaction technologies will help more effective 3D visualization of 3D information. They yield a realistic representation of 3D objects and simplifies our understanding to the complexity of 3D objects and spatial relationship among them. In this paper, we describe an autostereoscopic multiview 3D display system with capability of real-time user interaction. Design principle of this autostereoscopic multiview 3D display system is presented, together with the details of its hardware/software architecture. A prototype is built and tested based upon multi-projectors and horizontal optical anisotropic display structure. Experimental results illustrate the effectiveness of this novel 3D display and user interaction system.

  9. Will 3D printers manufacture your meals?

    NARCIS (Netherlands)

    Bommel, K.J.C. van

    2013-01-01

    These days, 3D printers are laying down plastics, metals, resins, and other materials in whatever configurations creative people can dream up. But when the next 3D printing revolution comes, you'll be able to eat it.

  10. 3D ultrasound in fetal spina bifida.

    Science.gov (United States)

    Schramm, T; Gloning, K-P; Minderer, S; Tutschek, B

    2008-12-01

    3D ultrasound can be used to study the fetal spine, but skeletal mode can be inconclusive for the diagnosis of fetal spina bifida. We illustrate a diagnostic approach using 2D and 3D ultrasound and indicate possible pitfalls.

  11. 3D Flash LIDAR Space Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) is a small business that has developed 3D Flash LIDAR systems for space and terrestrial applications. 3D Flash LIDAR is...

  12. Eesti 3D jaoks kitsas / Virge Haavasalu

    Index Scriptorium Estoniae

    Haavasalu, Virge

    2009-01-01

    Produktsioonifirma Digitaalne Sputnik: Kaur ja Kaspar Kallas tegelevad filmide produtseerimise ning 3D digitaalkaamerate tootearendusega (Silicon Imaging LLC). Vendade Kallaste 3D-kaamerast. Kommenteerib Eesti Filmi Sihtasutuse direktor Marge Liiske

  13. Will 3D printers manufacture your meals?

    NARCIS (Netherlands)

    Bommel, K.J.C. van

    2013-01-01

    These days, 3D printers are laying down plastics, metals, resins, and other materials in whatever configurations creative people can dream up. But when the next 3D printing revolution comes, you'll be able to eat it.

  14. 3D printing of microscopic bacterial communities

    National Research Council Canada - National Science Library

    Jodi L. Connell; Eric T. Ritschdorff; Marvin Whiteley; Jason B. Shear

    2013-01-01

    .... Here, we describe a microscopic threedimensional (3D) printing strategy that enables multiple populations of bacteria to be organized within essentially any 3D geometry, including adjacent, nested, and free-floating...

  15. 3D Scanning technology for offshore purposes

    DEFF Research Database (Denmark)

    Christoffersen, Morten Thoft

    2005-01-01

    New scanning technology makes for construction of precision 3D models of production plants and offshore production facilities......New scanning technology makes for construction of precision 3D models of production plants and offshore production facilities...

  16. Watermarking on 3D mesh based on spherical wavelet transform

    Institute of Scientific and Technical Information of China (English)

    金剑秋; 戴敏雅; 鲍虎军; 彭群生

    2004-01-01

    In this paper we propose a robust watermarking algorithm for 3D mesh. The algorithm is based on spherical wavelet transform. Our basic idea is to decompose the original mesh into a series of details at different scales by using spherical wavelet transform; the watermark is then embedded into the different levels of details. The embedding process includes: global sphere parameterization, spherical uniform sampling, spherical wavelet forward transform, embedding watermark, spherical wavelet inverse transform, and at last resampling the mesh watermarked to recover the topological connectivity of the original model. Experiments showed that our algorithm can improve the capacity of the watermark and the robustness of watermarking against attacks.

  17. Automatic Texture Optimization for 3D Urban Reconstruction

    Directory of Open Access Journals (Sweden)

    LI Ming

    2017-03-01

    Full Text Available In order to solve the problem of texture optimization in 3D city reconstruction by using multi-lens oblique images, the paper presents a method of seamless texture model reconstruction. At first, it corrects the radiation information of images by camera response functions and image dark channel. Then, according to the corresponding relevance between terrain triangular mesh surface model to image, implements occlusion detection by sparse triangulation method, and establishes the triangles' texture list of visible. Finally, combines with triangles' topology relationship in 3D triangular mesh surface model and means and variances of image, constructs a graph-cuts-based texture optimization algorithm under the framework of MRF(Markov random filed, to solve the discrete label problem of texture optimization selection and clustering, ensures the consistency of the adjacent triangles in texture mapping, achieves the seamless texture reconstruction of city. The experimental results verify the validity and superiority of our proposed method.

  18. The 3D Genome as Moderator of Chromosomal Communication.

    Science.gov (United States)

    Dekker, Job; Mirny, Leonid

    2016-03-10

    Proper expression of genes requires communication with their regulatory elements that can be located elsewhere along the chromosome. The physics of chromatin fibers imposes a range of constraints on such communication. The molecular and biophysical mechanisms by which chromosomal communication is established, or prevented, have become a topic of intense study, and important roles for the spatial organization of chromosomes are being discovered. Here we present a view of the interphase 3D genome characterized by extensive physical compartmentalization and insulation on the one hand and facilitated long-range interactions on the other. We propose the existence of topological machines dedicated to set up and to exploit a 3D genome organization to both promote and censor communication along and between chromosomes.

  19. Creating stable Floquet-Weyl semimetals by laser-driving of 3D Dirac materials

    Science.gov (United States)

    Hübener, Hannes; Sentef, Michael A.; de Giovannini, Umberto; Kemper, Alexander F.; Rubio, Angel

    2017-01-01

    Tuning and stabilizing topological states, such as Weyl semimetals, Dirac semimetals or topological insulators, is emerging as one of the major topics in materials science. Periodic driving of many-body systems offers a platform to design Floquet states of matter with tunable electronic properties on ultrafast timescales. Here we show by first principles calculations how femtosecond laser pulses with circularly polarized light can be used to switch between Weyl semimetal, Dirac semimetal and topological insulator states in a prototypical three-dimensional (3D) Dirac material, Na3Bi. Our findings are general and apply to any 3D Dirac semimetal. We discuss the concept of time-dependent bands and steering of Floquet-Weyl points and demonstrate how light can enhance topological protection against lattice perturbations. This work has potential practical implications for the ultrafast switching of materials properties, such as optical band gaps or anomalous magnetoresistance.

  20. Creating stable Floquet–Weyl semimetals by laser-driving of 3D Dirac materials

    Science.gov (United States)

    Hübener, Hannes; Sentef, Michael A.; De Giovannini, Umberto; Kemper, Alexander F.; Rubio, Angel

    2017-01-01

    Tuning and stabilizing topological states, such as Weyl semimetals, Dirac semimetals or topological insulators, is emerging as one of the major topics in materials science. Periodic driving of many-body systems offers a platform to design Floquet states of matter with tunable electronic properties on ultrafast timescales. Here we show by first principles calculations how femtosecond laser pulses with circularly polarized light can be used to switch between Weyl semimetal, Dirac semimetal and topological insulator states in a prototypical three-dimensional (3D) Dirac material, Na3Bi. Our findings are general and apply to any 3D Dirac semimetal. We discuss the concept of time-dependent bands and steering of Floquet–Weyl points and demonstrate how light can enhance topological protection against lattice perturbations. This work has potential practical implications for the ultrafast switching of materials properties, such as optical band gaps or anomalous magnetoresistance. PMID:28094286

  1. Laser Based 3D Volumetric Display System

    Science.gov (United States)

    1993-03-01

    Literature, Costa Mesa, CA July 1983. 3. "A Real Time Autostereoscopic Multiplanar 3D Display System", Rodney Don Williams, Felix Garcia, Jr., Texas...8217 .- NUMBERS LASER BASED 3D VOLUMETRIC DISPLAY SYSTEM PR: CD13 0. AUTHOR(S) PE: N/AWIU: DN303151 P. Soltan, J. Trias, W. Robinson, W. Dahlke 7...laser generated 3D volumetric images on a rotating double helix, (where the 3D displays are computer controlled for group viewing with the naked eye

  2. 3D-Printed Millimeter Wave Structures

    Science.gov (United States)

    2016-03-14

    demonstrates the resolution of the printer with a 10 micron nozzle. Figure 2: Measured loss tangent of SEBS and SBS samples. 3D - Printed Millimeter... 3D printing of styrene-butadiene-styrene (SBS) and styrene ethylene/butylene-styrene (SEBS) is used to demonstrate the feasibility of 3D - printed ...Additionally, a dielectric lens is printed which improves the antenna gain of an open-ended WR-28 waveguide from 7 to 8.5 dBi. Keywords: 3D printing

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

    Science.gov (United States)

    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

  4. 3D Printing and Its Urologic Applications

    Science.gov (United States)

    Soliman, Youssef; Feibus, Allison H; Baum, Neil

    2015-01-01

    3D printing is the development of 3D objects via an additive process in which successive layers of material are applied under computer control. This article discusses 3D printing, with an emphasis on its historical context and its potential use in the field of urology. PMID:26028997

  5. Beowulf 3D: a case study

    Science.gov (United States)

    Engle, Rob

    2008-02-01

    This paper discusses the creative and technical challenges encountered during the production of "Beowulf 3D," director Robert Zemeckis' adaptation of the Old English epic poem and the first film to be simultaneously released in IMAX 3D and digital 3D formats.

  6. Expanding Geometry Understanding with 3D Printing

    Science.gov (United States)

    Cochran, Jill A.; Cochran, Zane; Laney, Kendra; Dean, Mandi

    2016-01-01

    With the rise of personal desktop 3D printing, a wide spectrum of educational opportunities has become available for educators to leverage this technology in their classrooms. Until recently, the ability to create physical 3D models was well beyond the scope, skill, and budget of many schools. However, since desktop 3D printers have become readily…

  7. Imaging a Sustainable Future in 3D

    Science.gov (United States)

    Schuhr, W.; Lee, J. D.; Kanngieser, E.

    2012-07-01

    It is the intention of this paper, to contribute to a sustainable future by providing objective object information based on 3D photography as well as promoting 3D photography not only for scientists, but also for amateurs. Due to the presentation of this article by CIPA Task Group 3 on "3D Photographs in Cultural Heritage", the presented samples are masterpieces of historic as well as of current 3D photography concentrating on cultural heritage. In addition to a report on exemplarily access to international archives of 3D photographs, samples for new 3D photographs taken with modern 3D cameras, as well as by means of a ground based high resolution XLITE staff camera and also 3D photographs taken from a captive balloon and the use of civil drone platforms are dealt with. To advise on optimum suited 3D methodology, as well as to catch new trends in 3D, an updated synoptic overview of the 3D visualization technology, even claiming completeness, has been carried out as a result of a systematic survey. In this respect, e.g., today's lasered crystals might be "early bird" products in 3D, which, due to lack in resolution, contrast and color, remember to the stage of the invention of photography.

  8. 3D Printing and Its Urologic Applications.

    Science.gov (United States)

    Soliman, Youssef; Feibus, Allison H; Baum, Neil

    2015-01-01

    3D printing is the development of 3D objects via an additive process in which successive layers of material are applied under computer control. This article discusses 3D printing, with an emphasis on its historical context and its potential use in the field of urology.

  9. Expanding Geometry Understanding with 3D Printing

    Science.gov (United States)

    Cochran, Jill A.; Cochran, Zane; Laney, Kendra; Dean, Mandi

    2016-01-01

    With the rise of personal desktop 3D printing, a wide spectrum of educational opportunities has become available for educators to leverage this technology in their classrooms. Until recently, the ability to create physical 3D models was well beyond the scope, skill, and budget of many schools. However, since desktop 3D printers have become readily…

  10. 3D immersive and interactive learning

    CERN Document Server

    Cai, Yiyu

    2014-01-01

    This book reviews innovative uses of 3D for immersive and interactive learning, covering gifted programs, normal stream and special needs education. Reports on curriculum-based 3D learning in classrooms, and co-curriculum-based 3D student research projects.

  11. DISOCCLUSION OF 3D LIDAR POINT CLOUDS USING RANGE IMAGES

    Directory of Open Access Journals (Sweden)

    P. Biasutti

    2017-05-01

    Full Text Available This paper proposes a novel framework for the disocclusion of mobile objects in 3D LiDAR scenes aquired via street-based Mobile Mapping Systems (MMS. Most of the existing lines of research tackle this problem directly in the 3D space. This work promotes an alternative approach by using a 2D range image representation of the 3D point cloud, taking advantage of the fact that the problem of disocclusion has been intensively studied in the 2D image processing community over the past decade. First, the point cloud is turned into a 2D range image by exploiting the sensor’s topology. Using the range image, a semi-automatic segmentation procedure based on depth histograms is performed in order to select the occluding object to be removed. A variational image inpainting technique is then used to reconstruct the area occluded by that object. Finally, the range image is unprojected as a 3D point cloud. Experiments on real data prove the effectiveness of this procedure both in terms of accuracy and speed.

  12. 3D NETWORK ANALYSIS FOR INDOOR SPACE APPLICATIONS

    Directory of Open Access Journals (Sweden)

    E. Tsiliakou

    2016-10-01

    Full Text Available Indoor space differs from outdoor environments, since it is characterized by a higher level of structural complexity, geometry, as well as topological relations. Indoor space can be considered as the most important component in a building’s conceptual modelling, on which applications such as indoor navigation, routing or analysis are performed. Therefore, the conceptual meaning of sub spaces or the activities taking place in physical building boundaries (e.g. walls, require the comprehension of the building’s indoor hierarchical structure. The scope of this paper is to perform 3D network analysis in a building’s interior and is structured as follows: In Section 1 the definition of indoor space is provided and indoor navigation requirements are analysed. Section 2 describes the processes of indoor space modeling, as well as routing applications. In Section 3, a case study is examined involving a 3D building model generated in CityEngine (exterior shell and ArcScene (interior parts, in which the use of commercially available software tools (ArcGIS, ESRI, in terms of indoor routing and 3D network analysis, are explored. The fundamentals of performing 3D analysis with the ArcGIS Network Analyst extension were tested. Finally a geoprocessing model was presented, which was specifically designed to be used to interactively find the best route in ArcScene. The paper ends with discussion and concluding remarks on Section 4.

  13. 3D Network Analysis for Indoor Space Applications

    Science.gov (United States)

    Tsiliakou, E.; Dimopoulou, E.

    2016-10-01

    Indoor space differs from outdoor environments, since it is characterized by a higher level of structural complexity, geometry, as well as topological relations. Indoor space can be considered as the most important component in a building's conceptual modelling, on which applications such as indoor navigation, routing or analysis are performed. Therefore, the conceptual meaning of sub spaces or the activities taking place in physical building boundaries (e.g. walls), require the comprehension of the building's indoor hierarchical structure. The scope of this paper is to perform 3D network analysis in a building's interior and is structured as follows: In Section 1 the definition of indoor space is provided and indoor navigation requirements are analysed. Section 2 describes the processes of indoor space modeling, as well as routing applications. In Section 3, a case study is examined involving a 3D building model generated in CityEngine (exterior shell) and ArcScene (interior parts), in which the use of commercially available software tools (ArcGIS, ESRI), in terms of indoor routing and 3D network analysis, are explored. The fundamentals of performing 3D analysis with the ArcGIS Network Analyst extension were tested. Finally a geoprocessing model was presented, which was specifically designed to be used to interactively find the best route in ArcScene. The paper ends with discussion and concluding remarks on Section 4.

  14. Disocclusion of 3d LIDAR Point Clouds Using Range Images

    Science.gov (United States)

    Biasutti, P.; Aujol, J.-F.; Brédif, M.; Bugeau, A.

    2017-05-01

    This paper proposes a novel framework for the disocclusion of mobile objects in 3D LiDAR scenes aquired via street-based Mobile Mapping Systems (MMS). Most of the existing lines of research tackle this problem directly in the 3D space. This work promotes an alternative approach by using a 2D range image representation of the 3D point cloud, taking advantage of the fact that the problem of disocclusion has been intensively studied in the 2D image processing community over the past decade. First, the point cloud is turned into a 2D range image by exploiting the sensor's topology. Using the range image, a semi-automatic segmentation procedure based on depth histograms is performed in order to select the occluding object to be removed. A variational image inpainting technique is then used to reconstruct the area occluded by that object. Finally, the range image is unprojected as a 3D point cloud. Experiments on real data prove the effectiveness of this procedure both in terms of accuracy and speed.

  15. Topological nodal line semimetals

    Science.gov (United States)

    Fang, Chen; Weng, Hongming; Dai, Xi; Fang, Zhong

    2016-11-01

    We review the recent, mainly theoretical, progress in the study of topological nodal line semimetals in three dimensions. In these semimetals, the conduction and the valence bands cross each other along a one-dimensional curve in the three-dimensional Brillouin zone, and any perturbation that preserves a certain symmetry group (generated by either spatial symmetries or time-reversal symmetry) cannot remove this crossing line and open a full direct gap between the two bands. The nodal line(s) is hence topologically protected by the symmetry group, and can be associated with a topological invariant. In this review, (i) we enumerate the symmetry groups that may protect a topological nodal line; (ii) we write down the explicit form of the topological invariant for each of these symmetry groups in terms of the wave functions on the Fermi surface, establishing a topological classification; (iii) for certain classes, we review the proposals for the realization of these semimetals in real materials; (iv) we discuss different scenarios that when the protecting symmetry is broken, how a topological nodal line semimetal becomes Weyl semimetals, Dirac semimetals, and other topological phases; and (v) we discuss the possible physical effects accessible to experimental probes in these materials. Project partially supported by the National Key Research and Development Program of China (Grant Nos. 2016YFA0302400 and 2016YFA0300604), partially by the National Natural Science Foundation of China (Grant Nos. 11274359 and 11422428), the National Basic Research Program of China (Grant No. 2013CB921700), and the “Strategic Priority Research Program (B)” of the Chinese Academy of Sciences (Grant No. XDB07020100).

  16. Topology optimization for acoustic problems

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard

    2006-01-01

    In this paper a method to control acoustic properties in a room with topology optimization is presented. It is shown how the squared sound pressure amplitude in a certain part of a room can be minimized by distribution of material in a design domain along the ceiling in 2D and 3D. Nice 0-1 designs...

  17. Wafer level 3-D ICs process technology

    CERN Document Server

    Tan, Chuan Seng; Reif, L Rafael

    2009-01-01

    This book focuses on foundry-based process technology that enables the fabrication of 3-D ICs. The core of the book discusses the technology platform for pre-packaging wafer lever 3-D ICs. However, this book does not include a detailed discussion of 3-D ICs design and 3-D packaging. This is an edited book based on chapters contributed by various experts in the field of wafer-level 3-D ICs process technology. They are from academia, research labs and industry.

  18. View-based 3-D object retrieval

    CERN Document Server

    Gao, Yue

    2014-01-01

    Content-based 3-D object retrieval has attracted extensive attention recently and has applications in a variety of fields, such as, computer-aided design, tele-medicine,mobile multimedia, virtual reality, and entertainment. The development of efficient and effective content-based 3-D object retrieval techniques has enabled the use of fast 3-D reconstruction and model design. Recent technical progress, such as the development of camera technologies, has made it possible to capture the views of 3-D objects. As a result, view-based 3-D object retrieval has become an essential but challenging res

  19. Investigating Mobile Stereoscopic 3D Touchscreen Interaction

    OpenAIRE

    Colley, Ashley; Hakkila, Jonna; SCHOENING, Johannes; Posti, Maaret

    2013-01-01

    3D output is no longer limited to large screens in cinemas or living rooms. Nowadays more and more mobile devices are equipped with autostereoscopic 3D (S3D) touchscreens. As a consequence interaction with 3D content now also happens whilst users are on the move. In this paper we carried out a user study with 27 participants to assess how mobile interaction, i.e. whilst walking, with mobile S3D devices, differs from interaction with 2D mobile touchscreens. We investigate the difference in tou...

  20. The Topology of Three-Dimensional Symmetric Tensor Fields

    Science.gov (United States)

    Lavin, Yingmei; Levy, Yuval; Hesselink, Lambertus

    1994-01-01

    We study the topology of 3-D symmetric tensor fields. The goal is to represent their complex structure by a simple set of carefully chosen points and lines analogous to vector field topology. The basic constituents of tensor topology are the degenerate points, or points where eigenvalues are equal to each other. First, we introduce a new method for locating 3-D degenerate points. We then extract the topological skeletons of the eigenvector fields and use them for a compact, comprehensive description of the tensor field. Finally, we demonstrate the use of tensor field topology for the interpretation of the two-force Boussinesq problem.

  1. Case study: Beauty and the Beast 3D: benefits of 3D viewing for 2D to 3D conversion

    Science.gov (United States)

    Handy Turner, Tara

    2010-02-01

    From the earliest stages of the Beauty and the Beast 3D conversion project, the advantages of accurate desk-side 3D viewing was evident. While designing and testing the 2D to 3D conversion process, the engineering team at Walt Disney Animation Studios proposed a 3D viewing configuration that not only allowed artists to "compose" stereoscopic 3D but also improved efficiency by allowing artists to instantly detect which image features were essential to the stereoscopic appeal of a shot and which features had minimal or even negative impact. At a time when few commercial 3D monitors were available and few software packages provided 3D desk-side output, the team designed their own prototype devices and collaborated with vendors to create a "3D composing" workstation. This paper outlines the display technologies explored, final choices made for Beauty and the Beast 3D, wish-lists for future development and a few rules of thumb for composing compelling 2D to 3D conversions.

  2. Monopole-Based Scenarios of Confinement and Deconfinement in 3D and 4D

    Directory of Open Access Journals (Sweden)

    Dmitry Antonov

    2017-06-01

    Full Text Available This review discusses confinement, as well as the topological and critical phenomena, in the gauge theories which provide the condensation of magnetic monopoles. These theories include the 3D SU(N Georgi-Glashow model, the 4D [U(1] N - 1 -invariant compact QED , and the [U(1] N - 1 -invariant dual Abelian Higgs model. After a general introduction to the string models of confinement, an analytic description of this penomenon is provided at the example of the 3D SU(N Georgi-Glashow model, with a special emphasis placed on the so-called Casimir scaling of k-string tensions in that model. We further discuss the string representation of the 3D [U(1] N - 1 -invariant compact QED, as well as of its 4D generalization with the inclusion of the Θ -term. We compare topological effects, which appear in the latter case, with those that take place in the 3D QED extended by the Chern-Simons term. We further discuss the string representation of the ’t Hooft-loop average in the [U(1] N - 1 -invariant dual Abelian Higgs model extended by the Θ -term, along with the topological effects caused by this term. These topological effects are compared with those occurring in the 3D dual Abelian Higgs model (i.e., the dual Landau-Ginzburg theory extended by the Chern-Simons term. In the second part of the review, we discuss critical properties of the weakly-coupled 3D confining theories. These theories include the 3D compact QED, along with its fermionic extension, and the 3D Georgi-Glashow model.

  3. Universality of the topology of period doubling dynamical systems

    Energy Technology Data Exchange (ETDEWEB)

    Beiersdorfer, P.

    1983-10-01

    The evolution of the topology of the invariant manifolds of the attractors of 3-D autonomous dynamical systems during period doubling is shown to be universal. The overall topology of the nth attractor is shown to depend only on the topology of the first attractor at birth.

  4. Web-based interactive visualization of 3D video mosaics using X3D standard

    Institute of Scientific and Technical Information of China (English)

    CHON Jaechoon; LEE Yang-Won; SHIBASAKI Ryosuke

    2006-01-01

    We present a method of 3D image mosaicing for real 3D representation of roadside buildings, and implement a Web-based interactive visualization environment for the 3D video mosaics created by 3D image mosaicing. The 3D image mosaicing technique developed in our previous work is a very powerful method for creating textured 3D-GIS data without excessive data processing like the laser or stereo system. For the Web-based open access to the 3D video mosaics, we build an interactive visualization environment using X3D, the emerging standard of Web 3D. We conduct the data preprocessing for 3D video mosaics and the X3D modeling for textured 3D data. The data preprocessing includes the conversion of each frame of 3D video mosaics into concatenated image files that can be hyperlinked on the Web. The X3D modeling handles the representation of concatenated images using necessary X3D nodes. By employing X3D as the data format for 3D image mosaics, the real 3D representation of roadside buildings is extended to the Web and mobile service systems.

  5. Topological insulators and topological superconductors

    CERN Document Server

    Bernevig, Andrei B

    2013-01-01

    This graduate-level textbook is the first pedagogical synthesis of the field of topological insulators and superconductors, one of the most exciting areas of research in condensed matter physics. Presenting the latest developments, while providing all the calculations necessary for a self-contained and complete description of the discipline, it is ideal for graduate students and researchers preparing to work in this area, and it will be an essential reference both within and outside the classroom. The book begins with simple concepts such as Berry phases, Dirac fermions, Hall conductance and its link to topology, and the Hofstadter problem of lattice electrons in a magnetic field. It moves on to explain topological phases of matter such as Chern insulators, two- and three-dimensional topological insulators, and Majorana p-wave wires. Additionally, the book covers zero modes on vortices in topological superconductors, time-reversal topological superconductors, and topological responses/field theory and topolo...

  6. User-centered 3D geovisualisation

    DEFF Research Database (Denmark)

    Nielsen, Anette Hougaard

    2004-01-01

    3D Geovisualisation is a multidisciplinary science mainly utilizing geographically related data, developing software systems for 3D visualisation and producing relevant models. In this paper the connection between geoinformation stored as 3D objects and the end user is of special interest....... In a broader perspective, the overall aim is to develop a language in 3D Geovisualisation gained through usability projects and the development of a theoretical background. A conceptual level of user-centered 3D Geovisualisation is introduced by applying a categorisation originating from Virtual Reality....... The conceptual level is used to structure and organise user-centered 3D Geovisualisation into four categories: representation, rendering, interface and interaction. The categories reflect a process of development of 3D Geovisualisation where objects can be represented verisimilar to the real world...

  7. 3D laptop for defense applications

    Science.gov (United States)

    Edmondson, Richard; Chenault, David

    2012-06-01

    Polaris Sensor Technologies has developed numerous 3D display systems using a US Army patented approach. These displays have been developed as prototypes for handheld controllers for robotic systems and closed hatch driving, and as part of a TALON robot upgrade for 3D vision, providing depth perception for the operator for improved manipulation and hazard avoidance. In this paper we discuss the prototype rugged 3D laptop computer and its applications to defense missions. The prototype 3D laptop combines full temporal and spatial resolution display with the rugged Amrel laptop computer. The display is viewed through protective passive polarized eyewear, and allows combined 2D and 3D content. Uses include robot tele-operation with live 3D video or synthetically rendered scenery, mission planning and rehearsal, enhanced 3D data interpretation, and simulation.

  8. Topological Methods for Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Berres, Anne Sabine [Los Alamos National Lab. (LANL), Los Alamos, NM (United Stat

    2016-04-07

    This slide presentation describes basic topological concepts, including topological spaces, homeomorphisms, homotopy, betti numbers. Scalar field topology explores finding topological features and scalar field visualization, and vector field topology explores finding topological features and vector field visualization.

  9. Volume-Preserving Mapping and Registration for Collective Data Visualization.

    Science.gov (United States)

    Hu, Jiaxi; Zou, Guangyu Jeff; Hua, Jing

    2014-12-01

    In order to visualize and analyze complex collective data, complicated geometric structure of each data is desired to be mapped onto a canonical domain to enable map-based visual exploration. This paper proposes a novel volume-preserving mapping and registration method which facilitates effective collective data visualization. Given two 3-manifolds with the same topology, there exists a mapping between them to preserve each local volume element. Starting from an initial mapping, a volume restoring diffeomorphic flow is constructed as a compressible flow based on the volume forms at the manifold. Such a flow yields equality of each local volume element between the original manifold and the target at its final state. Furthermore, the salient features can be used to register the manifold to a reference template by an incompressible flow guided by a divergence-free vector field within the manifold. The process can retain the equality of local volume elements while registering the manifold to a template at the same time. An efficient and practical algorithm is also presented to generate a volume-preserving mapping and a salient feature registration on discrete 3D volumes which are represented with tetrahedral meshes embedded in 3D space. This method can be applied to comparative analysis and visualization of volumetric medical imaging data across subjects. We demonstrate an example application in multimodal neuroimaging data analysis and collective data visualization.

  10. Reconnection Experiments with Flux Ropes near 3D Magnetic Nulls

    Science.gov (United States)

    Vrublevskis, A.; Egedal, J.; Le, A.

    2012-12-01

    Magnetic reconnection has been predominantly investigated in two dimensions. However, depending on the topology and geometry of the magnetic field, a rich collection of magnetic reconnection scenarios is possible in 3D including reconnection at magnetic nulls. Nulls have been reported in the solar corona [1] and in Earth's magnetosphere [2], yet there are a limited number of laboratory observations. At the Versatile Toroidal Facility (VTF) we have implemented a new magnetic geometry with a pair of 3D null points in the background toroidal field. We form a flux rope along the background field and observe it to rapidly restructure and rewire as the nulls develop. We can adjust the topology of the configuration from one where a field line connects the nulls to one where the nulls are no longer linked. A suit of diagnostics will be deployed and results presented for the dynamics of the flux rope. [1] Fletcher et al., Astrophys. J. 554, 451(2001) [2] Xiao et al., Nat. Phys. 2, 478 (2006)

  11. RT3D tutorials for GMS users

    Energy Technology Data Exchange (ETDEWEB)

    Clement, T.P. [Pacific Northwest National Lab., Richland, WA (United States); Jones, N.L. [Brigham Young Univ., Provo, UT (United States)

    1998-02-01

    RT3D (Reactive Transport in 3-Dimensions) is a computer code that solves coupled partial differential equations that describe reactive-flow and transport of multiple mobile and/or immobile species in a three dimensional saturated porous media. RT3D was developed from the single-species transport code, MT3D (DoD-1.5, 1997 version). As with MT3D, RT3D also uses the USGS groundwater flow model MODFLOW for computing spatial and temporal variations in groundwater head distribution. This report presents a set of tutorial problems that are designed to illustrate how RT3D simulations can be performed within the Department of Defense Groundwater Modeling System (GMS). GMS serves as a pre- and post-processing interface for RT3D. GMS can be used to define all the input files needed by RT3D code, and later the code can be launched from within GMS and run as a separate application. Once the RT3D simulation is completed, the solution can be imported to GMS for graphical post-processing. RT3D v1.0 supports several reaction packages that can be used for simulating different types of reactive contaminants. Each of the tutorials, described below, provides training on a different RT3D reaction package. Each reaction package has different input requirements, and the tutorials are designed to describe these differences. Furthermore, the tutorials illustrate the various options available in GMS for graphical post-processing of RT3D results. Users are strongly encouraged to complete the tutorials before attempting to use RT3D and GMS on a routine basis.

  12. 3D change detection - Approaches and applications

    Science.gov (United States)

    Qin, Rongjun; Tian, Jiaojiao; Reinartz, Peter

    2016-12-01

    Due to the unprecedented technology development of sensors, platforms and algorithms for 3D data acquisition and generation, 3D spaceborne, airborne and close-range data, in the form of image based, Light Detection and Ranging (LiDAR) based point clouds, Digital Elevation Models (DEM) and 3D city models, become more accessible than ever before. Change detection (CD) or time-series data analysis in 3D has gained great attention due to its capability of providing volumetric dynamics to facilitate more applications and provide more accurate results. The state-of-the-art CD reviews aim to provide a comprehensive synthesis and to simplify the taxonomy of the traditional remote sensing CD techniques, which mainly sit within the boundary of 2D image/spectrum analysis, largely ignoring the particularities of 3D aspects of the data. The inclusion of 3D data for change detection (termed 3D CD), not only provides a source with different modality for analysis, but also transcends the border of traditional top-view 2D pixel/object-based analysis to highly detailed, oblique view or voxel-based geometric analysis. This paper reviews the recent developments and applications of 3D CD using remote sensing and close-range data, in support of both academia and industry researchers who seek for solutions in detecting and analyzing 3D dynamics of various objects of interest. We first describe the general considerations of 3D CD problems in different processing stages and identify CD types based on the information used, being the geometric comparison and geometric-spectral analysis. We then summarize relevant works and practices in urban, environment, ecology and civil applications, etc. Given the broad spectrum of applications and different types of 3D data, we discuss important issues in 3D CD methods. Finally, we present concluding remarks in algorithmic aspects of 3D CD.

  13. Beginning topology

    CERN Document Server

    Goodman, Sue E

    2009-01-01

    Beginning Topology is designed to give undergraduate students a broad notion of the scope of topology in areas of point-set, geometric, combinatorial, differential, and algebraic topology, including an introduction to knot theory. A primary goal is to expose students to some recent research and to get them actively involved in learning. Exercises and open-ended projects are placed throughout the text, making it adaptable to seminar-style classes. The book starts with a chapter introducing the basic concepts of point-set topology, with examples chosen to captivate students' imaginations while i

  14. Superconducting quantum criticality of topological surface states at three loops

    Science.gov (United States)

    Zerf, Nikolai; Lin, Chien-Hung; Maciejko, Joseph

    2016-11-01

    The semimetal-superconductor quantum phase transition on the two-dimensional (2D) surface of a 3D topological insulator is conjectured to exhibit an emergent N =2 supersymmetry, based on a one-loop renormalization group (RG) analysis in the ɛ expansion. We provide additional support for this conjecture by performing a three-loop RG analysis and showing that the supersymmetric fixed point found at this order survives the extrapolation to 2D. We compute critical exponents to order ɛ3, obtaining the more accurate value ν ≈0.985 for the correlation length exponent and confirming that the fermion and boson anomalous dimensions remain unchanged beyond one loop, as expected from non-renormalization theorems in supersymmetric theories. We further couple the system to a dynamical U(1) gauge field, and argue that the transition becomes fluctuation-induced first order in an appropriate type-I regime. We discuss implications of this result for quantum phase transitions between certain symmetry-preserving correlated surface states of 3D topological insulators.

  15. Methodologies for digital 3D acquisition and representation of mosaics

    Science.gov (United States)

    Manferdini, Anna Maria; Cipriani, Luca; Kniffitz, Linda

    2011-07-01

    Despite the recent improvements and widespread of digital technologies and their applications in the field of Cultural Heritage, nowadays Museums and Institutions still aren't encouraged to adopt digital procedures as a standard practice to collect data upon the heritage they are called to preserve and promote. One of the main reasons for this lack can be singled out in the high costs connected with these procedures and with their increasing due to difficulties connected with digital survey of artifacts and artworks which present evident intrinsic complexities and peculiarities that cannot be reconnected to recurrences. The aim of this paper is to show the results of a research conducted in order to find the most suitable digital methodology and procedure to be adopted to collect geometric and radiometric data upon mosaics that can straightforward both the preservation of the consistency of information about its geometry and the management of huge amount of data. One of the most immediate application of digital 3d survey of mosaics is the substitution of plaster casts that are usually built to add the third dimension to pictorial or photographic surveys before restoration interventions in order to document their conservation conditions and ease reconstruction procedures. Moreover, digital 3d surveys of mosaics allow to reproduce restoration interventions in digital environment able to perform reliable preliminary evaluations; in addition, 3d reality-based models of mosaics can be used within digital catalogues or for digital exhibitions and reconstruction aims.

  16. 3D Systems” ‘Stuck in the Middle’ of the 3D Printer Boom?

    NARCIS (Netherlands)

    A. Hoffmann (Alan)

    2014-01-01

    textabstract3D Systems, the pioneer of 3D printing, predicted a future where "kids from 8 to 80" could design and print their ideas at home. By 2013, 9 years after the creation of the first working 3D printer, there were more than 30 major 3D printing companies competing for market share. 3DS and it

  17. 3D-Barolo: 3D fitting tool for the kinematics of galaxies

    NARCIS (Netherlands)

    Di Teodoro, E. M.; Fraternali, F.

    3D-Barolo (3D-Based Analysis of Rotating Object via Line Observations) or BBarolo is a tool for fitting 3D tilted-ring models to emission-line datacubes. BBarolo works with 3D FITS files, i.e. image arrays with two spatial and one spectral dimensions. BBarolo recovers the true rotation curve and

  18. 3D Systems” ‘Stuck in the Middle’ of the 3D Printer Boom?

    NARCIS (Netherlands)

    A. Hoffmann (Alan)

    2014-01-01

    textabstract3D Systems, the pioneer of 3D printing, predicted a future where "kids from 8 to 80" could design and print their ideas at home. By 2013, 9 years after the creation of the first working 3D printer, there were more than 30 major 3D printing companies competing for market share. 3DS and

  19. Stability Criteria of 3D Inviscid Shears

    CERN Document Server

    Li, Y Charles

    2009-01-01

    The classical plane Couette flow, plane Poiseuille flow, and pipe Poiseuille flow share some universal 3D steady coherent structure in the form of "streak-roll-critical layer". As the Reynolds number approaches infinity, the steady coherent structure approaches a 3D limiting shear of the form ($U(y,z), 0, 0$) in velocity variables. All such 3D shears are steady states of the 3D Euler equations. This raises the importance of investigating the stability of such inviscid 3D shears in contrast to the classical Rayleigh theory of inviscid 2D shears. Several general criteria of stability for such inviscid 3D shears are derived. In the Appendix, an argument is given to show that a 2D limiting shear can only be the classical laminar shear.

  20. 3D-tulostus : case Printrbot

    OpenAIRE

    Arvekari, Lassi

    2013-01-01

    Opinnäytetyön tavoitteena on selvittää 3D-tulostustekniikan perusteita ja 3D-tulostuksen nykytilannetta. 3D-tulostukseen sopivien mallien luomista tutkitaan ja mallin tekemiseen on etsitty toimivia ohjesääntöjä. Tärkeä osa työtä on tutkia mitä vaiheita 3D-tulostimen hankinnassa kotikäyttöön tulee vastaan. Käytännön kokeita varten opinnäytetyössä on case Printrbot, jossa on tutustuttu edulliseen 3D-tulostuslaitteeseen kokoonpanosta lähtien. Työn kuluessa selvisi että edulliset 3D-tulos...

  1. Towards Automatic Semantic Labelling of 3D City Models

    Science.gov (United States)

    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.

  2. Field topologies in ideal and near-ideal magnetohydrodynamics and vortex dynamics

    Science.gov (United States)

    Low, B. C.

    2015-01-01

    Magnetic field topology frozen in ideal magnetohydrodynamics (MHD) and its breakage in near-ideal MHD are reviewed in two parts, clarifying and expanding basic concepts. The first part gives a physically complete description of the frozen field topology derived from magnetic flux conservation as the fundamental property, treating four conceptually related topics: Eulerian and Lagrangian descriptions of three dimensional (3D) MHD, Chandrasekhar-Kendall and Euler-potential field representations, magnetic helicity, and inviscid vortex dynamics as a fluid system in physical contrast to ideal MHD. A corollary of these developments clarifies the challenge of achieving a high degree of the frozen-in condition in numerical MHD. The second part treats field-topology breakage centered around the Parker Magnetostatic Theorem on a general incompatibility of a continuous magnetic field with the dual demand of force-free equilibrium and an arbitrarily prescribed, 3D field topology. Preserving field topology as a global constraint readily results in formation of tangential magnetic discontinuities, or, equivalently, electric current-sheets of zero thickness. A similar incompatibility is present in the steady force-thermal balance of a heated radiating fluid subject to an anisotropic thermal flux conducted strictly along its frozen-in magnetic field in the low- β limit. In a weakly resistive fluid the thinning of current sheets by these general incompatibilities inevitably results in sheet dissipation, resistive heating and topological changes in the field notwithstanding the small resistivity. Strong Faraday induction drives but also macroscopically limits this mode of energy dissipation, trapping or storing free energy in self-organized ideal-MHD structures. This property of MHD turbulence captured by the Taylor hypothesis is reviewed in relation to the Sun's corona, calling for a basic quantitative description of the breakdown of flux conservation in the low-resistivity limit

  3. Analysis of 3D-printed metal for rapid-prototyped reflective terahertz optics

    Science.gov (United States)

    Headland, Daniel; Withayachumnankul, Withawat; Webb, Michael; Ebendorff-Heidepriem, Heike; Luiten, Andre; Abbott, Derek

    2016-07-01

    We explore the potential of 3D metal printing to realize complex conductive terahertz devices. Factors impacting performance such as printing resolution, surface roughness, oxidation, and material loss are investigated via analytical, numerical, and experimental approaches. The high degree of control offered by a 3D-printed topology is exploited to realize a zone plate operating at 530 GHz. Reflection efficiency at this frequency is found to be over 90%. The high-performance of this preliminary device suggest that 3D metal printing can play a strong role in guided-wave and general beam control devices in the terahertz range.

  4. Analysis of 3D-printed metal for rapid-prototyped reflective terahertz optics

    CERN Document Server

    Headland, Daniel; Webb, Michael; Ebendorff-Heidepriem, Heike; Luiten, Andre; Abbott, Derek

    2016-01-01

    We explore the potential of 3D metal printing to realize complex conductive terahertz devices. Factors impacting performance such as printing resolution, surface roughness, oxidation, and material loss are investigated via analytical, numerical, and experimental approaches. The high degree of control offered by a 3D-printed topology is exploited to realize a zone plate operating at 530 GHz. Reflection efficiency at this frequency is found to be over 90%. The high-performance of this preliminary device suggest that 3D metal printing can play a strong role in guided-wave and general beam control devices in the terahertz range.

  5. ERP system for 3D printing industry

    Directory of Open Access Journals (Sweden)

    Deaky Bogdan

    2017-01-01

    Full Text Available GOCREATE is an original cloud-based production management and optimization service which helps 3D printing service providers to use their resources better. The proposed Enterprise Resource Planning system can significantly increase income through improved productivity. With GOCREATE, the 3D printing service providers get a much higher production efficiency at a much lower licensing cost, to increase their competitiveness in the fast growing 3D printing market.

  6. Reconhecimento de faces 3D com Kinect

    OpenAIRE

    Cardia Neto, João Baptista [UNESP

    2014-01-01

    For person identification, facil recognition has several advantages over other biometric traits due mostly to its high universelly, collectability, and acceptability. When dealing with 2D face images several problems arise related to pose, illumination, and facial expressions. To increase the performance of facial recognition, 3D mehtods have been proposed and developedm since working with 3D objects allow us to handle better the aforementioned problems. With 3D object, it is possible to rota...

  7. Ultrasonic Sensor Based 3D Mapping & Localization

    Directory of Open Access Journals (Sweden)

    Shadman Fahim Ahmad

    2016-04-01

    Full Text Available This article provides a basic level introduction to 3D mapping using sonar sensors and localization. It describes the methods used to construct a low-cost autonomous robot along with the hardware and software used as well as an insight to the background of autonomous robotic 3D mapping and localization. We have also given an overview to what the future prospects of the robot may hold in 3D based mapping.

  8. Twisted gauge theories in 3D Walker-Wang models

    CERN Document Server

    Wang, Zitao

    2016-01-01

    Three dimensional gauge theories with a discrete gauge group can emerge from spin models as a gapped topological phase with fractional point excitations (gauge charge) and loop excitations (gauge flux). It is known that 3D gauge theories can be "twisted", in the sense that the gauge flux loops can have nontrivial braiding statistics among themselves and such twisted gauge theories are realized in models discovered by Dijkgraaf and Witten. A different framework to systematically construct three dimensional topological phases was proposed by Walker and Wang and a series of examples have been studied. Can the Walker Wang construction be used to realize the topological order in twisted gauge theories? This is not immediately clear because the Walker-Wang construction is based on a loop condensation picture while the Dijkgraaf-Witten theory is based on a membrane condensation picture. In this paper, we show that the answer to this question is Yes, by presenting an explicit construction of the Walker Wang models wh...

  9. Topology evolutions of silhouettes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    We give the topology changing of the silhouette in 3D space while others study the projections in an image. Silhouettes play a crucial role in visualization, graphics and vision. This work focuses on the global behaviors of silhouettes, especially their topological evolutions, such as splitting, merging, appearing and disappearing. The dynamics of silhouettes are governed by the topology, the curvature of the surface, and the view point. In this paper, we work on a more theoretical level to give enumerative properties of the silhouette including: the integration of signed geodesic curvature along a silhouette is equal to the view cone angle; in elliptic regions, no silhouette can be contained in another one; in hyperbolic regions, ifa silhouette is homotopic to a point, then it has at least 4 cusps; finally, critical events can only happen when the view point is on the aspect surfaces (ruled surface of the asymptotic lines of parabolic points with surface itself). We also introduce a method to visualize the evolution of silhouettes, especially all the critical events where the topologies of the silhouettes change. The results have broad applications in computer vision for recognition, graphics for rendering and visualization.

  10. Ekologinen 3D-tulostettava asuste

    OpenAIRE

    Paulasaari, Laura

    2014-01-01

    Tämän opinnäytetyön aiheena oli ekologisuus 3D-tulostuksessa ja sen hyödynnettävyys erityisesti asustesuunnittelussa. Työn tarkoituksena oli selvittää, kuinka 3D-tulostusta voi tehdä ekologisemmin ja mitä vaihtoehtoja kuluttajalle tällä hetkellä on. Työ tehtiin Young skills –osuuskunnalle. 3D-tulostuksella on mahdollisuus antaa todella paljon tulevaisuuden tuotantomenetelmille ja se vapauttaa tuotteiden muotoilua täysin uudella tavalla. 3D-tulostuksen avulla voidaan keskittyä enemmän esim...

  11. Perspectives on Materials Science in 3D

    DEFF Research Database (Denmark)

    Juul Jensen, Dorte

    2016-01-01

    Materials characterization in 3D has opened a new era in materials science, which is discussed in this paper. The original motivations and visions behind the development of one of the new 3D techniques, namely the three dimensional x-ray diffraction (3DXRD) method, are presented and the route...... to its implementation is described. The present status of materials science in 3D is illustrated by examples related to recrystallization. Finally, challenges and suggestions for the future success for 3D Materials Science relating to hardware evolution, data analysis, data exchange and modeling...

  12. Virtual Realization using 3D Password

    Directory of Open Access Journals (Sweden)

    A.B.Gadicha

    2012-03-01

    Full Text Available Current authentication systems suffer from many weaknesses. Textual passwords are commonly used; however, users do not follow their requirements. Users tend to choose meaningful words from dictionaries, which make textual passwords easy to break and vulnerable to dictionary or brute force attacks. Many available graphical passwords have a password space that is less than or equal to the textual password space. Smart cards or tokens can be stolen. Many biometric authentications have been proposed; however, users tend to resist using biometrics because of their intrusiveness and the effect on their privacy. Moreover, biometrics cannot be revoked. In this paper, we present and evaluate our contribution, i.e., the 3D password. The 3D password is a multifactor authentication scheme. To be authenticated, we present a 3D virtual environment where the user navigates and interacts with various objects. The sequence of actions and interactions toward the objects inside the 3D environment constructs the user’s 3D password. The 3D password can combine most existing authentication schemes such as textual passwords, graphical passwords, and various types of biometrics into a 3D virtual environment. The design of the 3D virtual environment and the type of objects selected determine the 3D password key space.

  13. Dimensional accuracy of 3D printed vertebra

    Science.gov (United States)

    Ogden, Kent; Ordway, Nathaniel; Diallo, Dalanda; Tillapaugh-Fay, Gwen; Aslan, Can

    2014-03-01

    3D printer applications in the biomedical sciences and medical imaging are expanding and will have an increasing impact on the practice of medicine. Orthopedic and reconstructive surgery has been an obvious area for development of 3D printer applications as the segmentation of bony anatomy to generate printable models is relatively straightforward. There are important issues that should be addressed when using 3D printed models for applications that may affect patient care; in particular the dimensional accuracy of the printed parts needs to be high to avoid poor decisions being made prior to surgery or therapeutic procedures. In this work, the dimensional accuracy of 3D printed vertebral bodies derived from CT data for a cadaver spine is compared with direct measurements on the ex-vivo vertebra and with measurements made on the 3D rendered vertebra using commercial 3D image processing software. The vertebra was printed on a consumer grade 3D printer using an additive print process using PLA (polylactic acid) filament. Measurements were made for 15 different anatomic features of the vertebral body, including vertebral body height, endplate width and depth, pedicle height and width, and spinal canal width and depth, among others. It is shown that for the segmentation and printing process used, the results of measurements made on the 3D printed vertebral body are substantially the same as those produced by direct measurement on the vertebra and measurements made on the 3D rendered vertebra.

  14. Illustrating Mathematics using 3D Printers

    OpenAIRE

    Knill, Oliver; Slavkovsky, Elizabeth

    2013-01-01

    3D printing technology can help to visualize proofs in mathematics. In this document we aim to illustrate how 3D printing can help to visualize concepts and mathematical proofs. As already known to educators in ancient Greece, models allow to bring mathematics closer to the public. The new 3D printing technology makes the realization of such tools more accessible than ever. This is an updated version of a paper included in book Low-Cost 3D Printing for science, education and Sustainable Devel...

  15. Calibration for 3D Structured Light Measurement

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A calibration procedure was developed for three-dimensional(3D) binocular structured light measurement systems. In virtue of a specially designed pattern, matching points in stereo images are extracted. And then sufficient 3D space points are obtained through pairs of images with the intrinsic and extrinsic parameters of each camera estimated prior and consequently some lights are calibrated by means of multi point fitting. Finally, a mathematical model is applied to interpolate and approximate all dynamic scanning lights based on geometry. The process of calibration method is successfully used in the binocular 3D measurement system based on structured lights and the 3D reconstruction results are satisfying.

  16. Getting started in 3D with Maya

    CERN Document Server

    Watkins, Adam

    2012-01-01

    Deliver professional-level 3D content in no time with this comprehensive guide to 3D animation with Maya. With over 12 years of training experience, plus several award winning students under his belt, author Adam Watkins is the ideal mentor to get you up to speed with 3D in Maya. Using a structured and pragmatic approach Getting Started in 3D with Maya begins with basic theory of fundamental techniques, then builds on this knowledge using practical examples and projects to put your new skills to the test. Prepared so that you can learn in an organic fashion, each chapter builds on the know

  17. Holography in 3D AdS gravity with torsion

    CERN Document Server

    Blagojević, Milutin; Miskovic, Olivera; Olea, Rodrigo

    2013-01-01

    Basic aspects of the AdS/CFT correspondence are studied in the framework of 3-dimensional gravity with torsion. After choosing a consistent holographic ansatz, we formulate an improved approach to the Noether--Ward identities for the boundary theory. The method is applied first to the topological Mielke--Baekler model, and then to the more interesting (parity-preserving) 3-dimensional gravity with propagating torsion. In both cases, we find the finite holographic energy-momentum and spin currents and obtain the associated (anomalous) Noether--Ward identities.

  18. FastScript3D - A Companion to Java 3D

    Science.gov (United States)

    Koenig, Patti

    2005-01-01

    FastScript3D is a computer program, written in the Java 3D(TM) programming language, that establishes an alternative language that helps users who lack expertise in Java 3D to use Java 3D for constructing three-dimensional (3D)-appearing graphics. The FastScript3D language provides a set of simple, intuitive, one-line text-string commands for creating, controlling, and animating 3D models. The first word in a string is the name of a command; the rest of the string contains the data arguments for the command. The commands can also be used as an aid to learning Java 3D. Developers can extend the language by adding custom text-string commands. The commands can define new 3D objects or load representations of 3D objects from files in formats compatible with such other software systems as X3D. The text strings can be easily integrated into other languages. FastScript3D facilitates communication between scripting languages [which enable programming of hyper-text markup language (HTML) documents to interact with users] and Java 3D. The FastScript3D language can be extended and customized on both the scripting side and the Java 3D side.

  19. 3D dendritic gold nanostructures: seeded growth of a multi-generation fractal architecture.

    Science.gov (United States)

    Pan, Ming; Xing, Shuangxi; Sun, Ting; Zhou, Wenwen; Sindoro, Melinda; Teo, Hui Hian; Yan, Qingyu; Chen, Hongyu

    2010-10-14

    In this report, we focus on the synthetic challenges for nanoscale 3D fractal architectures, namely the multi-generation growth with control in both size uniformity and colloidal stability; by directing the simultaneous growth of Au and polyaniline on Au seeds, fractal nanoparticles can be achieved with a topology distinctively different from those of spheres, cubes or rods.

  20. Condensation of handles in the interface of 3D Ising model

    OpenAIRE

    Caselle, M.; Gliozzi, F.; Vinti, S.

    1993-01-01

    We analyze the microscopic, topological structure of the interface between domains of opposite magnetization in 3D Ising model near the critical point. This interface exhibits a fractal behaviour with a high density of handles. The mean area is an almost linear function of the genus. The entropy exponent is affected by strong finite-size effects.

  1. Modelling and analysing 3D buildings with a primal/dual data structure

    NARCIS (Netherlands)

    Boguslawski, P.; Gold, C.; Ledoux, H.

    2011-01-01

    While CityGML permits us to represent 3D city models, its use for applications where spatial analysis and/or real-time modifications are required is limited since at this moment the possibility to store topological relationships between the elements is rather limited and often not exploited. We pres

  2. Modelling and analysing 3D buildings with a primal/dual data structure

    NARCIS (Netherlands)

    Boguslawski, P.; Gold, C.; Ledoux, H.

    2011-01-01

    While CityGML permits us to represent 3D city models, its use for applications where spatial analysis and/or real-time modifications are required is limited since at this moment the possibility to store topological relationships between the elements is rather limited and often not exploited. We

  3. An aerial 3D printing test mission

    Science.gov (United States)

    Hirsch, Michael; McGuire, Thomas; Parsons, Michael; Leake, Skye; Straub, Jeremy

    2016-05-01

    This paper provides an overview of an aerial 3D printing technology, its development and its testing. This technology is potentially useful in its own right. In addition, this work advances the development of a related in-space 3D printing technology. A series of aerial 3D printing test missions, used to test the aerial printing technology, are discussed. Through completing these test missions, the design for an in-space 3D printer may be advanced. The current design for the in-space 3D printer involves focusing thermal energy to heat an extrusion head and allow for the extrusion of molten print material. Plastics can be used as well as composites including metal, allowing for the extrusion of conductive material. A variety of experiments will be used to test this initial 3D printer design. High altitude balloons will be used to test the effects of microgravity on 3D printing, as well as parabolic flight tests. Zero pressure balloons can be used to test the effect of long 3D printing missions subjected to low temperatures. Vacuum chambers will be used to test 3D printing in a vacuum environment. The results will be used to adapt a current prototype of an in-space 3D printer. Then, a small scale prototype can be sent into low-Earth orbit as a 3-U cube satellite. With the ability to 3D print in space demonstrated, future missions can launch production hardware through which the sustainability and durability of structures in space will be greatly improved.

  4. A Unified 3D Mesh Segmentation Framework Based on Markov Random Field

    Directory of Open Access Journals (Sweden)

    Z.F. Shi

    2012-04-01

    Full Text Available 3D Mesh segmentation has become an important research field in computer graphics during the past decades. Many geometry based and semantic oriented approaches for 3D mesh segmentation has been presented. In this paper, we present a definition of mesh segmentation according to labeling problem. Inspired by the Markov Random Field (MRF based image segmentation, we propose a new framework of 3D mesh segmentation based on MRF and use graph cuts to solve it. Any features of 3D mesh can be integrated into the segmentation framework. Experimental results show that the noise and over-segmentation are avoided. It also demonstrates that the proposed scheme has the capability of combining the geometric and topology information of the 3D mesh.

  5. FARGO3D: A new GPU-oriented MHD code

    CERN Document Server

    Benítez-Llambay, Pablo

    2016-01-01

    We present the FARGO3D code, recently publicly released. It is a magnetohydrodynamics code developed with special emphasis on protoplanetary disks physics and planet-disk interactions, and parallelized with MPI. The hydrodynamics algorithms are based on finite difference upwind, dimensionally split methods. The magnetohydrodynamics algorithms consist of the constrained transport method to preserve the divergence-free property of the magnetic field to machine accuracy, coupled to a method of characteristics for the evaluation of electromotive forces and Lorentz forces. Orbital advection is implemented, and an N-body solver is included to simulate planets or stars interacting with the gas. We present our implementation in detail and present a number of widely known tests for comparison purposes. One strength of FARGO3D is that it can run on both "Graphical Processing Units" (GPUs) or "Central Processing unit" (CPUs), achieving large speed up with respect to CPU cores. We describe our implementation choices, whi...

  6. Three-Phase Modulated Pole Machine Topologies Utilizing Mutual Flux Paths

    DEFF Research Database (Denmark)

    Washington, Jamie G.; Atkinson, Glynn J.; Baker, Nick J.

    2012-01-01

    This paper discusses three-phase topologies for modulated pole machines (MPMs). The authors introduce a new threephase topology, which takes advantage of mutual flux paths; this is analyzed using 3-D finite-element methods and compared to a three-phase topology using three single-phase units...... both performance and constructional benefits over prior MPM topologies....

  7. The 3D-city model

    DEFF Research Database (Denmark)

    Holmgren, Steen; Rüdiger, Bjarne; Tournay, Bruno

    2001-01-01

    We have worked with the construction and use of 3D city models for about ten years. This work has given us valuable experience concerning model methodology. In addition to this collection of knowledge, our perception of the concept of city models has changed radically. In order to explain...... of 3D city models....

  8. 3D, or Not to Be?

    Science.gov (United States)

    Norbury, Keith

    2012-01-01

    It may be too soon for students to be showing up for class with popcorn and gummy bears, but technology similar to that behind the 3D blockbuster movie "Avatar" is slowly finding its way into college classrooms. 3D classroom projectors are taking students on fantastic voyages inside the human body, to the ruins of ancient Greece--even to faraway…

  9. User-centered 3D geovisualisation

    DEFF Research Database (Denmark)

    Nielsen, Anette Hougaard

    2004-01-01

    . In a broader perspective, the overall aim is to develop a language in 3D Geovisualisation gained through usability projects and the development of a theoretical background. A conceptual level of user-centered 3D Geovisualisation is introduced by applying a categorisation originating from Virtual Reality...

  10. 3D Printing. What's the Harm?

    Science.gov (United States)

    Love, Tyler S.; Roy, Ken

    2016-01-01

    Health concerns from 3D printing were first documented by Stephens, Azimi, Orch, and Ramos (2013), who found that commercially available 3D printers were producing hazardous levels of ultrafine particles (UFPs) and volatile organic compounds (VOCs) when plastic materials were melted through the extruder. UFPs are particles less than 100 nanometers…

  11. 3D Printing of Molecular Models

    Science.gov (United States)

    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,…

  12. 3D printing of functional structures

    NARCIS (Netherlands)

    Krijnen, Gijsbertus J.M.

    2016-01-01

    The technology colloquial known as ‘3D printing’ has developed in such diversity in printing technologies and application fields that meanwhile it seems anything is possible. However, clearly the ideal 3D Printer, with high resolution, multi-material capability, fast printing, etc. is yet to be deve

  13. 3D printing of functional structures

    NARCIS (Netherlands)

    Krijnen, Gijsbertus J.M.

    The technology colloquial known as ‘3D printing’ has developed in such diversity in printing technologies and application fields that meanwhile it seems anything is possible. However, clearly the ideal 3D Printer, with high resolution, multi-material capability, fast printing, etc. is yet to be

  14. 3D Printed Block Copolymer Nanostructures

    Science.gov (United States)

    Scalfani, Vincent F.; Turner, C. Heath; Rupar, Paul A.; Jenkins, Alexander H.; Bara, Jason E.

    2015-01-01

    The emergence of 3D printing has dramatically advanced the availability of tangible molecular and extended solid models. Interestingly, there are few nanostructure models available both commercially and through other do-it-yourself approaches such as 3D printing. This is unfortunate given the importance of nanotechnology in science today. In this…

  15. 3D elastic control for mobile devices.

    Science.gov (United States)

    Hachet, Martin; Pouderoux, Joachim; Guitton, Pascal

    2008-01-01

    To increase the input space of mobile devices, the authors developed a proof-of-concept 3D elastic controller that easily adapts to mobile devices. This embedded device improves the completion of high-level interaction tasks such as visualization of large documents and navigation in 3D environments. It also opens new directions for tomorrow's mobile applications.

  16. Parametrizable cameras for 3D computational steering

    NARCIS (Netherlands)

    Mulder, J.D.; Wijk, J.J. van

    1997-01-01

    We present a method for the definition of multiple views in 3D interfaces for computational steering. The method uses the concept of a point-based parametrizable camera object. This concept enables a user to create and configure multiple views on his custom 3D interface in an intuitive graphical man

  17. 3D printing of functional structures

    NARCIS (Netherlands)

    Krijnen, G.J.M.

    2016-01-01

    The technology colloquial known as ‘3D printing’ has developed in such diversity in printing technologies and application fields that meanwhile it seems anything is possible. However, clearly the ideal 3D Printer, with high resolution, multi-material capability, fast printing, etc. is yet to be deve

  18. 3D Printed Block Copolymer Nanostructures

    Science.gov (United States)

    Scalfani, Vincent F.; Turner, C. Heath; Rupar, Paul A.; Jenkins, Alexander H.; Bara, Jason E.

    2015-01-01

    The emergence of 3D printing has dramatically advanced the availability of tangible molecular and extended solid models. Interestingly, there are few nanostructure models available both commercially and through other do-it-yourself approaches such as 3D printing. This is unfortunate given the importance of nanotechnology in science today. In this…

  19. 3D Printing of Molecular Models

    Science.gov (United States)

    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,…

  20. 3D Printing. What's the Harm?

    Science.gov (United States)

    Love, Tyler S.; Roy, Ken

    2016-01-01

    Health concerns from 3D printing were first documented by Stephens, Azimi, Orch, and Ramos (2013), who found that commercially available 3D printers were producing hazardous levels of ultrafine particles (UFPs) and volatile organic compounds (VOCs) when plastic materials were melted through the extruder. UFPs are particles less than 100 nanometers…

  1. 3D background aerodynamics using CFD

    DEFF Research Database (Denmark)

    Sørensen, Niels N.

    2002-01-01

    3D rotor computations for the Greek Geovilogiki (GEO) 44 meter rotor equipped with 19 meters blades are performed. The lift and drag polars are extracted at five spanvise locations r/R= (.37, .55, .71, .82, .93) based on identification of stagnationpoints between 2D and 3D computations. The inner...

  2. Integration of real-time 3D image acquisition and multiview 3D display

    Science.gov (United States)

    Zhang, Zhaoxing; Geng, Zheng; Li, Tuotuo; Li, Wei; Wang, Jingyi; Liu, Yongchun

    2014-03-01

    Seamless integration of 3D acquisition and 3D display systems offers enhanced experience in 3D visualization of the real world objects or scenes. The vivid representation of captured 3D objects displayed on a glasses-free 3D display screen could bring the realistic viewing experience to viewers as if they are viewing real-world scene. Although the technologies in 3D acquisition and 3D display have advanced rapidly in recent years, effort is lacking in studying the seamless integration of these two different aspects of 3D technologies. In this paper, we describe our recent progress on integrating a light-field 3D acquisition system and an autostereoscopic multiview 3D display for real-time light field capture and display. This paper focuses on both the architecture design and the implementation of the hardware and the software of this integrated 3D system. A prototype of the integrated 3D system is built to demonstrate the real-time 3D acquisition and 3D display capability of our proposed system.

  3. 2D/3D switchable displays

    Science.gov (United States)

    Dekker, T.; de Zwart, S. T.; Willemsen, O. H.; Hiddink, M. G. H.; IJzerman, W. L.

    2006-02-01

    A prerequisite for a wide market acceptance of 3D displays is the ability to switch between 3D and full resolution 2D. In this paper we present a robust and cost effective concept for an auto-stereoscopic switchable 2D/3D display. The display is based on an LCD panel, equipped with switchable LC-filled lenticular lenses. We will discuss 3D image quality, with the focus on display uniformity. We show that slanting the lenticulars in combination with a good lens design can minimize non-uniformities in our 20" 2D/3D monitors. Furthermore, we introduce fractional viewing systems as a very robust concept to further improve uniformity in the case slanting the lenticulars and optimizing the lens design are not sufficient. We will discuss measurements and numerical simulations of the key optical characteristics of this display. Finally, we discuss 2D image quality, the switching characteristics and the residual lens effect.

  4. Density-Based 3D Shape Descriptors

    Directory of Open Access Journals (Sweden)

    Schmitt Francis

    2007-01-01

    Full Text Available We propose a novel probabilistic framework for the extraction of density-based 3D shape descriptors using kernel density estimation. Our descriptors are derived from the probability density functions (pdf of local surface features characterizing the 3D object geometry. Assuming that the shape of the 3D object is represented as a mesh consisting of triangles with arbitrary size and shape, we provide efficient means to approximate the moments of geometric features on a triangle basis. Our framework produces a number of 3D shape descriptors that prove to be quite discriminative in retrieval applications. We test our descriptors and compare them with several other histogram-based methods on two 3D model databases, Princeton Shape Benchmark and Sculpteur, which are fundamentally different in semantic content and mesh quality. Experimental results show that our methodology not only improves the performance of existing descriptors, but also provides a rigorous framework to advance and to test new ones.

  5. Fabrication of 3D Silicon Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Kok, A.; Hansen, T.E.; Hansen, T.A.; Lietaer, N.; Summanwar, A.; /SINTEF, Oslo; Kenney, C.; Hasi, J.; /SLAC; Da Via, C.; /Manchester U.; Parker, S.I.; /Hawaii U.

    2012-06-06

    Silicon sensors with a three-dimensional (3-D) architecture, in which the n and p electrodes penetrate through the entire substrate, have many advantages over planar silicon sensors including radiation hardness, fast time response, active edge and dual readout capabilities. The fabrication of 3D sensors is however rather complex. In recent years, there have been worldwide activities on 3D fabrication. SINTEF in collaboration with Stanford Nanofabrication Facility have successfully fabricated the original (single sided double column type) 3D detectors in two prototype runs and the third run is now on-going. This paper reports the status of this fabrication work and the resulted yield. The work of other groups such as the development of double sided 3D detectors is also briefly reported.

  6. Maintaining and troubleshooting your 3D printer

    CERN Document Server

    Bell, Charles

    2014-01-01

    Maintaining and Troubleshooting Your 3D Printer by Charles Bell is your guide to keeping your 3D printer running through preventive maintenance, repair, and diagnosing and solving problems in 3D printing. If you've bought or built a 3D printer such as a MakerBot only to be confounded by jagged edges, corner lift, top layers that aren't solid, or any of a myriad of other problems that plague 3D printer enthusiasts, then here is the book to help you get past all that and recapture the joy of creative fabrication. The book also includes valuable tips for builders and those who want to modify the

  7. 3D Visualization Development of SIUE Campus

    Science.gov (United States)

    Nellutla, Shravya

    Geographic Information Systems (GIS) has progressed from the traditional map-making to the modern technology where the information can be created, edited, managed and analyzed. Like any other models, maps are simplified representations of real world. Hence visualization plays an essential role in the applications of GIS. The use of sophisticated visualization tools and methods, especially three dimensional (3D) modeling, has been rising considerably due to the advancement of technology. There are currently many off-the-shelf technologies available in the market to build 3D GIS models. One of the objectives of this research was to examine the available ArcGIS and its extensions for 3D modeling and visualization and use them to depict a real world scenario. Furthermore, with the advent of the web, a platform for accessing and sharing spatial information on the Internet, it is possible to generate interactive online maps. Integrating Internet capacity with GIS functionality redefines the process of sharing and processing the spatial information. Enabling a 3D map online requires off-the-shelf GIS software, 3D model builders, web server, web applications and client server technologies. Such environments are either complicated or expensive because of the amount of hardware and software involved. Therefore, the second objective of this research was to investigate and develop simpler yet cost-effective 3D modeling approach that uses available ArcGIS suite products and the free 3D computer graphics software for designing 3D world scenes. Both ArcGIS Explorer and ArcGIS Online will be used to demonstrate the way of sharing and distributing 3D geographic information on the Internet. A case study of the development of 3D campus for the Southern Illinois University Edwardsville is demonstrated.

  8. The psychology of the 3D experience

    Science.gov (United States)

    Janicke, Sophie H.; Ellis, Andrew

    2013-03-01

    With 3D televisions expected to reach 50% home saturation as early as 2016, understanding the psychological mechanisms underlying the user response to 3D technology is critical for content providers, educators and academics. Unfortunately, research examining the effects of 3D technology has not kept pace with the technology's rapid adoption, resulting in large-scale use of a technology about which very little is actually known. Recognizing this need for new research, we conducted a series of studies measuring and comparing many of the variables and processes underlying both 2D and 3D media experiences. In our first study, we found narratives within primetime dramas had the power to shift viewer attitudes in both 2D and 3D settings. However, we found no difference in persuasive power between 2D and 3D content. We contend this lack of effect was the result of poor conversion quality and the unique demands of 3D production. In our second study, we found 3D technology significantly increased enjoyment when viewing sports content, yet offered no added enjoyment when viewing a movie trailer. The enhanced enjoyment of the sports content was shown to be the result of heightened emotional arousal and attention in the 3D condition. We believe the lack of effect found for the movie trailer may be genre-related. In our final study, we found 3D technology significantly enhanced enjoyment of two video games from different genres. The added enjoyment was found to be the result of an increased sense of presence.

  9. 3D Shape Modeling Using High Level Descriptors

    DEFF Research Database (Denmark)

    Andersen, Vedrana

    The goal of this Ph.D. project is to investigate and improve the methods for describing the surface of 3D objects, with focus on modeling geometric texture on surfaces. Surface modeling being a large field of research, the work done during this project concentrated around a few smaller areas corr...... of my work involved developing feature-aware resizing of models with complex surfaces consisting of underlying shape and a distinctive texture detail. The aim was to deform an object while preserving the shape and size of the features....

  10. TopSig: Topology Preserving Document Signatures

    CERN Document Server

    Geva, Shlomo

    2012-01-01

    Performance comparisons between File Signatures and Inverted Files for text retrieval have previously shown several significant shortcomings of file signatures relative to inverted files. The inverted file approach underpins most state-of-the-art search engine algorithms, such as Language and Probabilistic models. It has been widely accepted that traditional file signatures are inferior alternatives to inverted files. This paper describes TopSig, a new approach to the construction of file signatures. Many advances in semantic hashing and dimensionality reduction have been made in recent times, but these were not so far linked to general purpose, signature file based, search engines. This paper introduces a different signature file approach that builds upon and extends these recent advances. We are able to demonstrate significant improvements in the performance of signature file based indexing and retrieval, performance that is comparable to that of state of the art inverted file based systems, including Langu...

  11. Magnetic and Magnetoresistive Properties of 3D Interconnected NiCo Nanowire Networks

    Science.gov (United States)

    da Câmara Santa Clara Gomes, Tristan; De La Torre Medina, Joaquín; Lemaitre, Matthieu; Piraux, Luc

    2016-10-01

    Track-etched polymer membranes with crossed nanochannels have been revealed to be most suitable as templates to produce large surface area and mechanically stable 3D interconnected nanowire (NW) networks by electrodeposition. Geometrically controlled NW superstructures made of NiCo ferromagnetic alloys exhibit appealing magnetoresistive properties. The combination of exact alloy compositions with the spatial arrangement of NWs in the 3D network is decisive to obtain specific magnetic and magneto-transport behavior. A proposed simple model based on topological aspects of the 3D NW networks is used to accurately determine the anisotropic magnetoresistance ratios. Despite of their complex topology, the microstructure of Co-rich NiCo NW networks display mixed fcc-hcp phases with the c-axis of the hcp phase oriented perpendicular to their axis. These interconnected NW networks have high potential as reliable and stable magnetic field sensors.

  12. A New Method of Identifying 3D Null Points in Solar Vector Magnetic Fields

    Institute of Scientific and Technical Information of China (English)

    Hui Zhao; Jing-Xiu Wang; Jun Zhang; Chi-Jie Xiao

    2005-01-01

    Employing the Poincaré index of isolated null-points in a vector field,we worked out a mathematical method of searching for 3D null-points in coronal magnetic fields. After introducing the relevant differential topology, we test the method by using the analytical model of Brown & Priest. The location of nullpoint identified by our method coincides precisely with the analytical solution.Finally we apply the method to the 3D coronal magnetic fields reconstructed from an observed MDI magnetogram of a super-active region (NOAA 10488). We find that the 3D null-point seems to be a key element in the magnetic topology associated with flare occurrence.

  13. Toric topology

    CERN Document Server

    Buchstaber, Victor M

    2015-01-01

    This book is about toric topology, a new area of mathematics that emerged at the end of the 1990s on the border of equivariant topology, algebraic and symplectic geometry, combinatorics, and commutative algebra. It has quickly grown into a very active area with many links to other areas of mathematics, and continues to attract experts from different fields. The key players in toric topology are moment-angle manifolds, a class of manifolds with torus actions defined in combinatorial terms. Construction of moment-angle manifolds relates to combinatorial geometry and algebraic geometry of toric v

  14. Topological Manifolds

    Directory of Open Access Journals (Sweden)

    Pąk Karol

    2015-02-01

    Full Text Available Let us recall that a topological space M is a topological manifold if M is second-countable Hausdorff and locally Euclidean, i.e. each point has a neighborhood that is homeomorphic to an open ball of E n for some n. However, if we would like to consider a topological manifold with a boundary, we have to extend this definition. Therefore, we introduce here the concept of a locally Euclidean space that covers both cases (with and without a boundary, i.e. where each point has a neighborhood that is homeomorphic to a closed ball of En for some n.

  15. Topological insulators

    CERN Document Server

    Franz, Marcel

    2013-01-01

    Topological Insulators, volume six in the Contemporary Concepts of Condensed Matter Series, describes the recent revolution in condensed matter physics that occurred in our understanding of crystalline solids. The book chronicles the work done worldwide that led to these discoveries and provides the reader with a comprehensive overview of the field. Starting in 2004, theorists began to explore the effect of topology on the physics of band insulators, a field previously considered well understood. However, the inclusion of topology brings key new elements into this old field. Whereas it was

  16. Topological fields

    CERN Document Server

    Warner, S

    1989-01-01

    Aimed at those acquainted with basic point-set topology and algebra, this text goes up to the frontiers of current research in topological fields (more precisely, topological rings that algebraically are fields).The reader is given enough background to tackle the current literature without undue additional preparation. Many results not in the text (and many illustrations by example of theorems in the text) are included among the exercises. Sufficient hints for the solution of the exercises are offered so that solving them does not become a major research effort for the reader. A comprehensive bibliography completes the volume.

  17. Topology optimization of flow problems

    DEFF Research Database (Denmark)

    Gersborg, Allan Roulund

    2007-01-01

    of the velocity field or mixing properties. To reduce the computational complexity of the topology optimization problems the primary focus is put on the Stokes equation in 2D and in 3D. However, the thesis also contains examples with the 2D Navier-Stokes equation as well as an example with convection dominated....... Although the study of the FVM is carried out using a simple heat conduction problem, the work illuminates and discusses the technicalities of employing the FVM in connection with topology optimization. Finally, parallelized solution methods are investigated using the high performance computing facility...

  18. Digital relief generation from 3D models

    Science.gov (United States)

    Wang, Meili; Sun, Yu; Zhang, Hongming; Qian, Kun; Chang, Jian; He, Dongjian

    2016-09-01

    It is difficult to extend image-based relief generation to high-relief generation, as the images contain insufficient height information. To generate reliefs from three-dimensional (3D) models, it is necessary to extract the height fields from the model, but this can only generate bas-reliefs. To overcome this problem, an efficient method is proposed to generate bas-reliefs and high-reliefs directly from 3D meshes. To produce relief features that are visually appropriate, the 3D meshes are first scaled. 3D unsharp masking is used to enhance the visual features in the 3D mesh, and average smoothing and Laplacian smoothing are implemented to achieve better smoothing results. A nonlinear variable scaling scheme is then employed to generate the final bas-reliefs and high-reliefs. Using the proposed method, relief models can be generated from arbitrary viewing positions with different gestures and combinations of multiple 3D models. The generated relief models can be printed by 3D printers. The proposed method provides a means of generating both high-reliefs and bas-reliefs in an efficient and effective way under the appropriate scaling factors.

  19. 3D imaging in forensic odontology.

    Science.gov (United States)

    Evans, Sam; Jones, Carl; Plassmann, Peter

    2010-06-16

    This paper describes the investigation of a new 3D capture method for acquiring and subsequent forensic analysis of bite mark injuries on human skin. When documenting bite marks with standard 2D cameras errors in photographic technique can occur if best practice is not followed. Subsequent forensic analysis of the mark is problematic when a 3D structure is recorded into a 2D space. Although strict guidelines (BAFO) exist, these are time-consuming to follow and, due to their complexity, may produce errors. A 3D image capture and processing system might avoid the problems resulting from the 2D reduction process, simplifying the guidelines and reducing errors. Proposed Solution: a series of experiments are described in this paper to demonstrate that the potential of a 3D system might produce suitable results. The experiments tested precision and accuracy of the traditional 2D and 3D methods. A 3D image capture device minimises the amount of angular distortion, therefore such a system has the potential to create more robust forensic evidence for use in courts. A first set of experiments tested and demonstrated which method of forensic analysis creates the least amount of intra-operator error. A second set tested and demonstrated which method of image capture creates the least amount of inter-operator error and visual distortion. In a third set the effects of angular distortion on 2D and 3D methods of image capture were evaluated.

  20. Medical 3D Printing for the Radiologist.

    Science.gov (United States)

    Mitsouras, Dimitris; Liacouras, Peter; Imanzadeh, Amir; Giannopoulos, Andreas A; Cai, Tianrun; Kumamaru, Kanako K; George, Elizabeth; Wake, Nicole; Caterson, Edward J; Pomahac, Bohdan; Ho, Vincent B; Grant, Gerald T; Rybicki, Frank J

    2015-01-01

    While use of advanced visualization in radiology is instrumental in diagnosis and communication with referring clinicians, there is an unmet need to render Digital Imaging and Communications in Medicine (DICOM) images as three-dimensional (3D) printed models capable of providing both tactile feedback and tangible depth information about anatomic and pathologic states. Three-dimensional printed models, already entrenched in the nonmedical sciences, are rapidly being embraced in medicine as well as in the lay community. Incorporating 3D printing from images generated and interpreted by radiologists presents particular challenges, including training, materials and equipment, and guidelines. The overall costs of a 3D printing laboratory must be balanced by the clinical benefits. It is expected that the number of 3D-printed models generated from DICOM images for planning interventions and fabricating implants will grow exponentially. Radiologists should at a minimum be familiar with 3D printing as it relates to their field, including types of 3D printing technologies and materials used to create 3D-printed anatomic models, published applications of models to date, and clinical benefits in radiology. Online supplemental material is available for this article. (©)RSNA, 2015.

  1. 3D Reconstruction Technique for Tomographic PIV

    Institute of Scientific and Technical Information of China (English)

    姜楠; 包全; 杨绍琼

    2015-01-01

    Tomographic particle image velocimetry(Tomo-PIV) is a state-of-the-art experimental technique based on a method of optical tomography to achieve the three-dimensional(3D) reconstruction for three-dimensional three-component(3D-3C) flow velocity measurements. 3D reconstruction for Tomo-PIV is carried out herein. Meanwhile, a 3D simplified tomographic reconstruction model reduced from a 3D volume light inten-sity field with 2D projection images into a 2D Tomo-slice plane with 1D projecting lines, i.e., simplifying this 3D reconstruction into a problem of 2D Tomo-slice plane reconstruction, is applied thereafter. Two kinds of the most well-known algebraic reconstruction techniques, algebraic reconstruction technique(ART) and multiple algebraic reconstruction technique(MART), are compared as well. The principles of the two reconstruction algorithms are discussed in detail, which has been performed by a series of simulation images, yielding the corresponding recon-struction images that show different features between the ART and MART algorithm, and then their advantages and disadvantages are discussed. Further discussions are made for the standard particle image reconstruction when the background noise of the pre-initial particle image has been removed. Results show that the particle image recon-struction has been greatly improved. The MART algorithm is much better than the ART. Furthermore, the computa-tional analyses of two parameters(the particle density and the number of cameras), are performed to study their effects on the reconstruction. Lastly, the 3D volume particle field is reconstructed by using the improved algorithm based on the simplified 3D tomographic reconstruction model, which proves that the algorithm simplification is feasible and it can be applied to the reconstruction of 3D volume particle field in a Tomo-PIV system.

  2. 3D object-oriented image analysis in 3D geophysical modelling

    DEFF Research Database (Denmark)

    Fadel, I.; van der Meijde, M.; Kerle, N.

    2015-01-01

    Non-uniqueness of satellite gravity interpretation has traditionally been reduced by using a priori information from seismic tomography models. This reduction in the non-uniqueness has been based on velocity-density conversion formulas or user interpretation of the 3D subsurface structures (objects......) based on the seismic tomography models and then forward modelling these objects. However, this form of object-based approach has been done without a standardized methodology on how to extract the subsurface structures from the 3D models. In this research, a 3D object-oriented image analysis (3D OOA......) approach was implemented to extract the 3D subsurface structures from geophysical data. The approach was applied on a 3D shear wave seismic tomography model of the central part of the East African Rift System. Subsequently, the extracted 3D objects from the tomography model were reconstructed in the 3D...

  3. Differential topology

    CERN Document Server

    Mukherjee, Amiya

    2015-01-01

    This book presents a systematic and comprehensive account of the theory of differentiable manifolds and provides the necessary background for the use of fundamental differential topology tools. The text includes, in particular, the earlier works of Stephen Smale, for which he was awarded the Fields Medal. Explicitly, the topics covered are Thom transversality, Morse theory, theory of handle presentation, h-cobordism theorem, and the generalised Poincaré conjecture. The material is the outcome of lectures and seminars on various aspects of differentiable manifolds and differential topology given over the years at the Indian Statistical Institute in Calcutta, and at other universities throughout India. The book will appeal to graduate students and researchers interested in these topics. An elementary knowledge of linear algebra, general topology, multivariate calculus, analysis, and algebraic topology is recommended.

  4. The reactor dynamics code DYN3D

    Energy Technology Data Exchange (ETDEWEB)

    Kliem, Soeren; Bilodid, Yuri; Fridman, Emil; Baier, Silvio; Grahn, Alexander; Gommlich, Andre; Nikitin, Evgeny; Rohde, Ulrich [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany)

    2016-05-15

    The article provides an overview on the code DYN3D which is a three-dimensional core model for steady-state, dynamic and depletion calculations in reactor cores with quadratic or hexagonal fuel assembly geometry being developed by the Helmholtz-Zentrum Dresden-Rossendorf for more than 20 years. The current paper gives an overview on the basic DYN3D models and the available code couplings. The verification and validation status is shortly outlined. The paper concludes with the current developments of the DYN3D code. For more detailed information the reader is referred to the publications cited in the corresponding chapters.

  5. Automatic balancing of 3D models

    DEFF Research Database (Denmark)

    Christiansen, Asger Nyman; Schmidt, Ryan; Bærentzen, Jakob Andreas

    2014-01-01

    3D printing technologies allow for more diverse shapes than are possible with molds and the cost of making just one single object is negligible compared to traditional production methods. However, not all shapes are suitable for 3D print. One of the remaining costs is therefore human time spent......, in these cases, we will apply a rotation of the object which only deforms the shape a little near the base. No user input is required but it is possible to specify manufacturing constraints related to specific 3D print technologies. Several models have successfully been balanced and printed using both polyjet...

  6. Participation and 3D Visualization Tools

    DEFF Research Database (Denmark)

    Mullins, Michael; Jensen, Mikkel Holm; Henriksen, Sune

    2004-01-01

    With a departure point in a workshop held at the VR Media Lab at Aalborg University , this paper deals with aspects of public participation and the use of 3D visualisation tools. The workshop grew from a desire to involve a broad collaboration between the many actors in the city through using new...... perceptions of architectural representation in urban design where 3D visualisation techniques are used. It is the authors? general finding that, while 3D visualisation media have the potential to increase understanding of virtual space for the lay public, as well as for professionals, the lay public require...

  7. Computer Modelling of 3D Geological Surface

    CERN Document Server

    Kodge, B G

    2011-01-01

    The geological surveying presently uses methods and tools for the computer modeling of 3D-structures of the geographical subsurface and geotechnical characterization as well as the application of geoinformation systems for management and analysis of spatial data, and their cartographic presentation. The objectives of this paper are to present a 3D geological surface model of Latur district in Maharashtra state of India. This study is undertaken through the several processes which are discussed in this paper to generate and visualize the automated 3D geological surface model of a projected area.

  8. RHOCUBE: 3D density distributions modeling code

    Science.gov (United States)

    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.

  9. A high capacity 3D steganography algorithm.

    Science.gov (United States)

    Chao, Min-Wen; Lin, Chao-hung; Yu, Cheng-Wei; Lee, Tong-Yee

    2009-01-01

    In this paper, we present a very high-capacity and low-distortion 3D steganography scheme. Our steganography approach is based on a novel multilayered embedding scheme to hide secret messages in the vertices of 3D polygon models. Experimental results show that the cover model distortion is very small as the number of hiding layers ranges from 7 to 13 layers. To the best of our knowledge, this novel approach can provide much higher hiding capacity than other state-of-the-art approaches, while obeying the low distortion and security basic requirements for steganography on 3D models.

  10. FUN3D Manual: 12.7

    Science.gov (United States)

    Biedron, Robert T.; Carlson, Jan-Renee; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bil; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; hide

    2015-01-01

    This manual describes the installation and execution of FUN3D version 12.7, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.

  11. FUN3D Manual: 12.9

    Science.gov (United States)

    Biedron, Robert T.; Carlson, Jan-Renee; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bil; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; hide

    2016-01-01

    This manual describes the installation and execution of FUN3D version 12.9, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.

  12. FUN3D Manual: 12.8

    Science.gov (United States)

    Biedron, Robert T.; Carlson, Jan-Renee; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bil; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; hide

    2015-01-01

    This manual describes the installation and execution of FUN3D version 12.8, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.

  13. FUN3D Manual: 13.1

    Science.gov (United States)

    Biedron, Robert T.; Carlson, Jan-Renee; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bil; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; hide

    2017-01-01

    This manual describes the installation and execution of FUN3D version 13.1, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.

  14. FUN3D Manual: 13.0

    Science.gov (United States)

    Biedron, Robert T.; Carlson, Jan-Renee; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bill; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; hide

    2016-01-01

    This manual describes the installation and execution of FUN3D version 13.0, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.

  15. 3D face modeling, analysis and recognition

    CERN Document Server

    Daoudi, Mohamed; Veltkamp, Remco

    2013-01-01

    3D Face Modeling, Analysis and Recognition presents methodologies for analyzing shapes of facial surfaces, develops computational tools for analyzing 3D face data, and illustrates them using state-of-the-art applications. The methodologies chosen are based on efficient representations, metrics, comparisons, and classifications of features that are especially relevant in the context of 3D measurements of human faces. These frameworks have a long-term utility in face analysis, taking into account the anticipated improvements in data collection, data storage, processing speeds, and application s

  16. Advanced 3D Printers for Cellular Solids

    Science.gov (United States)

    2016-06-30

    SECURITY CLASSIFICATION OF: Final Report for DURIP grant W911NF-14-1-0416 This DURIP grant has allowed for the purchase of three 3D printers ...06-2016 1-Aug-2014 31-Dec-2015 Final Report: Advanced 3D printers for Cellular Solids The views, opinions and/or findings contained in this report are...Papers published in non peer-reviewed journals: Final Report: Advanced 3D printers for Cellular Solids Report Title Final Report for DURIP grant W911NF

  17. 3D Printing the ATLAS' barrel toroid

    CERN Document Server

    Goncalves, Tiago Barreiro

    2016-01-01

    The present report summarizes my work as part of the Summer Student Programme 2016 in the CERN IR-ECO-TSP department (International Relations – Education, Communication & Outreach – Teacher and Student Programmes). Particularly, I worked closely with the S’Cool LAB team on a science education project. This project included the 3D designing, 3D printing, and assembling of a model of the ATLAS’ barrel toroid. A detailed description of the project' development is presented and a short manual on how to use 3D printing software and hardware is attached.

  18. 3D Immersive Visualization with Astrophysical Data

    Science.gov (United States)

    Kent, Brian R.

    2017-01-01

    We present the refinement of a new 3D immersion technique for astrophysical data visualization.Methodology to create 360 degree spherical panoramas is reviewed. The 3D software package Blender coupled with Python and the Google Spatial Media module are used together to create the final data products. Data can be viewed interactively with a mobile phone or tablet or in a web browser. The technique can apply to different kinds of astronomical data including 3D stellar and galaxy catalogs, images, and planetary maps.

  19. FUN3D Manual: 12.6

    Science.gov (United States)

    Biedron, Robert T.; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, William L.; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; Rumsey, Christopher L.; Thomas, James L.; Wood, William A.

    2015-01-01

    This manual describes the installation and execution of FUN3D version 12.6, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.

  20. FUN3D Manual: 12.5

    Science.gov (United States)

    Biedron, Robert T.; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, William L.; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; Rumsey, Christopher L.; Thomas, James L.; Wood, William A.

    2014-01-01

    This manual describes the installation and execution of FUN3D version 12.5, including optional dependent packages. FUN3D is a suite of computational uid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables ecient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.