A theory of general solutions of 3D problems in 1D hexagonal quasicrystals
International Nuclear Information System (INIS)
Gao Yang; Xu Sipeng; Zhao Baosheng
2008-01-01
A theory of general solutions of three-dimensional (3D) problems is developed for the coupled equilibrium equations in 1D hexagonal quasicrystals (QCs), and two new general solutions, which are called generalized Lekhnitskii-Hu-Nowacki (LHN) and Elliott-Lodge (E-L) solutions, respectively, are presented based on three theorems. As a special case, the generalized LHN solution is obtained from our previous general solution by introducing three high-order displacement functions. For further simplification, considering three cases in which three characteristic roots are distinct or possibly equal to each other, the generalized E-L solution shall take different forms, and be expressed in terms of four quasi-harmonic functions which are very simple and useful. It is proved that the general solution presented by Peng and Fan is consistent with one case of the generalized E-L solution, while does not include the other two cases. It is important to note that generalized LHN and E-L solutions are complete in z-convex domains, while incomplete in the usual non-z-convex domains
Vatankhah, Saeed; Renaut, Rosemary A.; Ardestani, Vahid E.
2018-04-01
We present a fast algorithm for the total variation regularization of the 3-D gravity inverse problem. Through imposition of the total variation regularization, subsurface structures presenting with sharp discontinuities are preserved better than when using a conventional minimum-structure inversion. The associated problem formulation for the regularization is nonlinear but can be solved using an iteratively reweighted least-squares algorithm. For small-scale problems the regularized least-squares problem at each iteration can be solved using the generalized singular value decomposition. This is not feasible for large-scale, or even moderate-scale, problems. Instead we introduce the use of a randomized generalized singular value decomposition in order to reduce the dimensions of the problem and provide an effective and efficient solution technique. For further efficiency an alternating direction algorithm is used to implement the total variation weighting operator within the iteratively reweighted least-squares algorithm. Presented results for synthetic examples demonstrate that the novel randomized decomposition provides good accuracy for reduced computational and memory demands as compared to use of classical approaches.
International Nuclear Information System (INIS)
Riemke, Richard Allan
2001-01-01
The Reactor Excursion and Leak Analysis Program with 3D capability (RELAP5-3D) is a reactor system analysis code that has been developed at the Idaho National Engineering and Environmental Laboratory (INEEL) for the U. S. Department of Energy (DOE). The 3D capability in RELAP5-3D includes 3D hydrodynamics and 3D neutron kinetics. Assessment, verification, and validation of the 3D capability in RELAP5-3D is discussed in the literature. Additional assessment, verification, and validation of the 3D capability of RELAP5-3D will be presented in other papers in this users seminar. As with any software, user problems occur. User problems usually fall into the categories of input processing failure, code execution failure, restart/renodalization failure, unphysical result, and installation. This presentation will discuss some of the more generic user problems that have been reported on RELAP5-3D as well as their resolution
Energy Technology Data Exchange (ETDEWEB)
Riemke, Richard Allan
2002-09-01
The Reactor Excursion and Leak Analysis Program with 3D capability1 (RELAP5-3D) is a reactor system analysis code that has been developed at the Idaho National Engineering and Environmental Laboratory (INEEL) for the U. S. Department of Energy (DOE). The 3D capability in RELAP5-3D includes 3D hydrodynamics2 and 3D neutron kinetics3,4. Assessment, verification, and validation of the 3D capability in RELAP5-3D is discussed in the literature5,6,7,8,9,10. Additional assessment, verification, and validation of the 3D capability of RELAP5-3D will be presented in other papers in this users seminar. As with any software, user problems occur. User problems usually fall into the categories of input processing failure, code execution failure, restart/renodalization failure, unphysical result, and installation. This presentation will discuss some of the more generic user problems that have been reported on RELAP5-3D as well as their resolution.
a Proposal for Generalization of 3d Models
Uyar, A.; Ulugtekin, N. N.
2017-11-01
In recent years, 3D models have been created of many cities around the world. Most of the 3D city models have been introduced as completely graphic or geometric models, and the semantic and topographic aspects of the models have been neglected. In order to use 3D city models beyond the task, a generalization is necessary. CityGML is an open data model and XML-based format for the storage and exchange of virtual 3D city models. Level of Details (LoD) which is an important concept for 3D modelling, can be defined as outlined degree or prior representation of real-world objects. The paper aim is first describes some requirements of 3D model generalization, then presents problems and approaches that have been developed in recent years. In conclude the paper will be a summary and outlook on problems and future work.
A Harmonic Algorithm for the 3D Strip Packing Problem
N. Bansal (Nikhil); X. Han; K. Iwama; M. Sviridenko; G. Zhang (Guochuan)
2013-01-01
htmlabstractIn the three-dimensional (3D) strip packing problem, we are given a set of 3D rectangular items and a 3D box $B$. The goal is to pack all the items in $B$ such that the height of the packing is minimized. We consider the most basic version of the problem, where the items must be packed
Nonconformity problem in 3D Grid decomposition
Czech Academy of Sciences Publication Activity Database
Kolcun, Alexej
2002-01-01
Roč. 10, č. 1 (2002), s. 249-253 ISSN 1213-6972. [International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision 2002/10./. Plzeň, 04.02.2002-08.02.2002] R&D Projects: GA ČR GA105/99/1229; GA ČR GA105/01/1242 Institutional research plan: CEZ:AV0Z3086906 Keywords : structured mesh * decomposition * nonconformity Subject RIV: BA - General Mathematics
Unitarity problems in 3D gravity theories
Alkac, Gokhan; Basanisi, Luca; Kilicarslan, Ercan; Tekin, Bayram
2017-07-01
We revisit the problem of the bulk-boundary unitarity clash in 2 +1 -dimensional gravity theories, which has been an obstacle in providing a viable dual two-dimensional conformal field theory for bulk gravity in anti-de Sitter (AdS) spacetime. Chiral gravity, which is a particular limit of cosmological topologically massive gravity (TMG), suffers from perturbative log-modes with negative energies inducing a nonunitary logarithmic boundary field theory. We show here that any f (R ) extension of TMG does not improve the situation. We also study the perturbative modes in the metric formulation of minimal massive gravity—originally constructed in a first-order formulation—and find that the massive mode has again negative energy except in the chiral limit. We comment on this issue and also discuss a possible solution to the problem of negative-energy modes. In any of these theories, the infinitesimal dangerous deformations might not be integrable to full solutions; this suggests a linearization instability of AdS spacetime in the direction of the perturbative log-modes.
New computational methodology for large 3D neutron transport problems
International Nuclear Information System (INIS)
Dahmani, M.; Roy, R.; Koclas, J.
2004-01-01
We present a new computational methodology, based on 3D characteristics method, dedicated to solve very large 3D problems without spatial homogenization. In order to eliminate the input/output problems occurring when solving these large problems, we set up a new computing scheme that requires more CPU resources than the usual one, based on sweeps over large tracking files. The huge capacity of storage needed in some problems and the related I/O queries needed by the characteristics solver are replaced by on-the-fly recalculation of tracks at each iteration step. Using this technique, large 3D problems are no longer I/O-bound, and distributed CPU resources can be efficiently used. (authors)
International Nuclear Information System (INIS)
2005-01-01
This article presents the general problems as natural disasters, consequences of global climate change, public health, the danger of criminal actions, the availability to information about problems of environment
Topology optimization of 3D Stokes flow problems
DEFF Research Database (Denmark)
Gersborg-Hansen, Allan; Sigmund, Ole; Bendsøe, Martin P.
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...... particular at micro scales since they are easily manufacturable and maintenance free. Here we consider topology optimization of 3D Stokes flow problems which is a reasonable fluid model to use at small scales. The presentation elaborates on effects caused by 3D fluid modelling on the design. Numerical...
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 present talk is concerned with the application of topology optimization to creeping flow problems in 3D. This research is driven by the fact that topology optimization has proven very successful as a tool in academic and industrial design problems. Success stories are reported from such diverse...
A 3D stylized half-core CANDU benchmark problem
International Nuclear Information System (INIS)
Pounders, Justin M.; Rahnema, Farzad; Serghiuta, Dumitru; Tholammakkil, John
2011-01-01
A 3D stylized half-core Canadian deuterium uranium (CANDU) reactor benchmark problem is presented. The benchmark problem is comprised of a heterogeneous lattice of 37-element natural uranium fuel bundles, heavy water moderated, heavy water cooled, with adjuster rods included as reactivity control devices. Furthermore, a 2-group macroscopic cross section library has been developed for the problem to increase the utility of this benchmark for full-core deterministic transport methods development. Monte Carlo results are presented for the benchmark problem in cooled, checkerboard void, and full coolant void configurations.
An analytical statistical approach to the 3D reconstruction problem
Energy Technology Data Exchange (ETDEWEB)
Cierniak, Robert [Czestochowa Univ. of Technology (Poland). Inst. of Computer Engineering
2011-07-01
The presented here approach is concerned with the reconstruction problem for 3D spiral X-ray tomography. The reconstruction problem is formulated taking into considerations the statistical properties of signals obtained in X-ray CT. Additinally, image processing performed in our approach is involved in analytical methodology. This conception significantly improves quality of the obtained after reconstruction images and decreases the complexity of the reconstruction problem in comparison with other approaches. Computer simulations proved that schematically described here reconstruction algorithm outperforms conventional analytical methods in obtained image quality. (orig.)
2D and 3D Traveling Salesman Problem
Haxhimusa, Yll; Carpenter, Edward; Catrambone, Joseph; Foldes, David; Stefanov, Emil; Arns, Laura; Pizlo, Zygmunt
2011-01-01
When a two-dimensional (2D) traveling salesman problem (TSP) is presented on a computer screen, human subjects can produce near-optimal tours in linear time. In this study we tested human performance on a real and virtual floor, as well as in a three-dimensional (3D) virtual space. Human performance on the real floor is as good as that on a…
A highly simplified 3D BWR benchmark problem
International Nuclear Information System (INIS)
Douglass, Steven; Rahnema, Farzad
2010-01-01
The resurgent interest in reactor development associated with the nuclear renaissance has paralleled significant advancements in computer technology, and allowed for unprecedented computational power to be applied to the numerical solution of neutron transport problems. The current generation of core-level solvers relies on a variety of approximate methods (e.g. nodal diffusion theory, spatial homogenization) to efficiently solve reactor problems with limited computer power; however, in recent years, the increased availability of high-performance computer systems has created an interest in the development of new methods and codes (deterministic and Monte Carlo) to directly solve whole-core reactor problems with full heterogeneity (lattice and core level). This paper presents the development of a highly simplified heterogeneous 3D benchmark problem with physics characteristic of boiling water reactors. The aim of this work is to provide a problem for developers to use to validate new whole-core methods and codes which take advantage of the advanced computational capabilities that are now available. Additionally, eigenvalues and an overview of the pin fission density distribution are provided for the benefit of the reader. (author)
Krylov Techniques for 3D Problems in Transport Theory
International Nuclear Information System (INIS)
Ruben Panta Pazos
2006-01-01
When solving integral-differential equations by means of numerical methods one has to deal with large systems of linear equations, such as happens in transport theory [10]. Many iterative techniques are now used in Transport Theory in order to solve problems of 2D and 3D dimensions. In this paper, we choose two problems to solve the following transport equation, [Equation] where x: represents the spatial variable, μ: the cosine of the angle, ψ: the angular flux, h(x, μ): is the collision frequency, k(x, μ, μ'): the scattering kernel, q(x, μ): the source. The aim of this work is the straightforward application of the Krylov spaces technique [2] to the governing equation or to its discretizations derived of the discrete ordinates method (choosing a finite number of directions and then approximating the integral term by means of a proper sum). The equation (1) can be written in functional form as [Equation] with ψ in the Hilbert space L 2 ([0,a] x [-1,1])., and q is the source function. The operator derived from a discrete ordinates scheme that approximates the operator [Equation] generates the following subspace [Equation] i.e. the subspace generated by the iterations of order 0, 1, 2,..., m-1 of the source function q. Two methods are specially outstanding, the Lanczos method to solve the problem given by equation (2) with certain boundary conditions, and the conjugate gradient method to solve the same problem with identical boundary conditions. We discuss and accelerate the basic iterative method [8]. An important conclusion is the generation of these methods to solve linear systems in Hilbert spaces, if verify the convergence conditions, which are outlined in this work. The first problem is a cubic domain with two regions, one with a source near the vertex at the origin and the shield region. In this case, the Cartesian planes (specifically 0 < x < L, 0 < y < L, 0 < z < L) are reflexive boundaries and the rest faces of the cube are vacuum boundaries. The
Solution accelerators for large scale 3D electromagnetic inverse problems
International Nuclear Information System (INIS)
Newman, Gregory A.; Boggs, Paul T.
2004-01-01
We provide a framework for preconditioning nonlinear 3D electromagnetic inverse scattering problems using nonlinear conjugate gradient (NLCG) and limited memory (LM) quasi-Newton methods. Key to our approach is the use of an approximate adjoint method that allows for an economical approximation of the Hessian that is updated at each inversion iteration. Using this approximate Hessian as a preconditoner, we show that the preconditioned NLCG iteration converges significantly faster than the non-preconditioned iteration, as well as converging to a data misfit level below that observed for the non-preconditioned method. Similar conclusions are also observed for the LM iteration; preconditioned with the approximate Hessian, the LM iteration converges faster than the non-preconditioned version. At this time, however, we see little difference between the convergence performance of the preconditioned LM scheme and the preconditioned NLCG scheme. A possible reason for this outcome is the behavior of the line search within the LM iteration. It was anticipated that, near convergence, a step size of one would be approached, but what was observed, instead, were step lengths that were nowhere near one. We provide some insights into the reasons for this behavior and suggest further research that may improve the performance of the LM methods
Analysis of the NEACRP PWR rod ejection benchmark problems with DIF3D-K
International Nuclear Information System (INIS)
Kim, M.H.
1994-01-01
Analyses of the NEACRP PWR rod ejection transient benchmark problems with the DIF3D-K nodal kinetics code are presented. The DIF3D-K results are shown to be in generally good agreement with results obtained using other codes, in particular reference results previously generated with the PANTHER code. The sensitivity of the transient results to the DIF3D-K input parameters (such as time step size, radial and axial node sizes, and the mesh structure employed for fuel pin heat conduction calculation) are evaluated and discussed. In addition, the potential in reducing computational effort by application of the improved quasistatic scheme (IQS) to these rod ejection transients, which involve very significant flux shape changes and thermal-hydraulic feedback is evaluated
Definition of new 3D invariants. Applications to pattern recognition problems with neural networks
International Nuclear Information System (INIS)
Proriol, J.
1996-01-01
We propose a definition of new 3D invariants. Usual pattern recognition methods use 2D descriptions of 3D objects, we propose a 2D approximation of the defined 3D invariants which can be used with neural networks to solve pattern recognition problems. We describe some methods to use the 2 D approximants. This work is an extension of previous 3D invariants used to solve some high energy physics problems. (author)
Generalized 3D Zernike functions for analytic construction of band-limited line-detecting wavelets
Janssen, A.J.E.M.
2015-01-01
We consider 3D versions of the Zernike polynomials that are commonly used in 2D in optics and lithography. We generalize the 3D Zernike polynomials to functions that vanish to a prescribed degree $\\alpha\\geq0$ at the rim of their supporting ball $\\rho\\leq1$. The analytic theory of the 3D generalized
Inverse problems in vision and 3D tomography
Mohamad-Djafari, Ali
2013-01-01
The concept of an inverse problem is a familiar one to most scientists and engineers, particularly in the field of signal and image processing, imaging systems (medical, geophysical, industrial non-destructive testing, etc.) and computer vision. In imaging systems, the aim is not just to estimate unobserved images, but also their geometric characteristics from observed quantities that are linked to these unobserved quantities through the forward problem. This book focuses on imagery and vision problems that can be clearly written in terms of an inverse problem where an estimate for the image a
Generalized Hough transform based time invariant action recognition with 3D pose information
Muench, David; Huebner, Wolfgang; Arens, Michael
2014-10-01
Human action recognition has emerged as an important field in the computer vision community due to its large number of applications such as automatic video surveillance, content based video-search and human robot interaction. In order to cope with the challenges that this large variety of applications present, recent research has focused more on developing classifiers able to detect several actions in more natural and unconstrained video sequences. The invariance discrimination tradeoff in action recognition has been addressed by utilizing a Generalized Hough Transform. As a basis for action representation we transform 3D poses into a robust feature space, referred to as pose descriptors. For each action class a one-dimensional temporal voting space is constructed. Votes are generated from associating pose descriptors with their position in time relative to the end of an action sequence. Training data consists of manually segmented action sequences. In the detection phase valid human 3D poses are assumed as input, e.g. originating from 3D sensors or monocular pose reconstruction methods. The human 3D poses are normalized to gain view-independence and transformed into (i) relative limb-angle space to ensure independence of non-adjacent joints or (ii) geometric features. In (i) an action descriptor consists of the relative angles between limbs and their temporal derivatives. In (ii) the action descriptor consists of different geometric features. In order to circumvent the problem of time-warping we propose to use a codebook of prototypical 3D poses which is generated from sample sequences of 3D motion capture data. This idea is in accordance with the concept of equivalence classes in action space. Results of the codebook method are presented using the Kinect sensor and the CMU Motion Capture Database.
IMPSOR, 3-D Boundary Problems Solution for Thermal Conductivity Calculation
International Nuclear Information System (INIS)
Wilson, D.G.; Williams, M.A.
1994-01-01
1 - Description of program or function: IMPSOR implements finite difference methods for multidimensional moving boundary problems with Dirichlet or Neumann boundary conditions. The geometry of the spatial domain is a rectangular parallelepiped with dimensions specified by the user. Dirichlet or Neumann boundary conditions may be specified on each face of the box independently. The user defines the initial and boundary conditions as well as the thermal and physical properties of the problem and several parameters for the numerical method, e.g. degree of implicitness, time-step size. 2 - Method of solution: The spatial domain is partitioned and the governing equation discretized, which yields a nonlinear system of equations at each time-step. This nonlinear system is solved using a successive over-relaxation (SOR) algorithm. For a given node, the previous iteration's temperature and thermal conductivity values are used for advanced points with current values at previous points. This constitutes a Gauss-Seidel iteration. Most of the computing time used by the numerical method is spent in the iterative solution of the nonlinear system. The SOR scheme employed is designed to accommodate vectorization on a Cray X-MP. 3 - Restrictions on the complexity of the problem: Maximum of 70,000 nodes
Generalized balanced power diagrams for 3D representations of polycrystals
DEFF Research Database (Denmark)
Alpers, Andreas; Brieden, Andreas; Gritzmann, Peter
2015-01-01
Characterizing the grain structure of polycrystalline material is an important task in material science. The present paper introduces the concept of generalized balanced power diagrams as a concise alternative to voxelated mappings. Here, each grain is represented by (measured approximations of...
Numerical nonlinear complex geometrical optics algorithm for the 3D Calderón problem
DEFF Research Database (Denmark)
Delbary, Fabrice; Knudsen, Kim
2014-01-01
to the generalized Laplace equation. The 3D problem was solved in theory in late 1980s using complex geometrical optics solutions and a scattering transform. Several approximations to the reconstruction method have been suggested and implemented numerically in the literature, but here, for the first time, a complete...... computer implementation of the full nonlinear algorithm is given. First a boundary integral equation is solved by a Nystrom method for the traces of the complex geometrical optics solutions, second the scattering transform is computed and inverted using fast Fourier transform, and finally a boundary value...
Generalized 3D Zernike functions for analytic construction of band-limited line-detecting wavelets
Janssen, Augustus J. E. M.
2015-01-01
We consider 3D versions of the Zernike polynomials that are commonly used in 2D in optics and lithography. We generalize the 3D Zernike polynomials to functions that vanish to a prescribed degree $\\alpha\\geq0$ at the rim of their supporting ball $\\rho\\leq1$. The analytic theory of the 3D generalized Zernike functions is developed, with attention for computational results for their Fourier transform, Funk and Radon transform, and scaling operations. The Fourier transform of generalized 3D Zern...
Iterative observer based method for source localization problem for Poisson equation in 3D
Majeed, Muhammad Usman
2017-07-10
A state-observer based method is developed to solve point source localization problem for Poisson equation in a 3D rectangular prism with available boundary data. The technique requires a weighted sum of solutions of multiple boundary data estimation problems for Laplace equation over the 3D domain. The solution of each of these boundary estimation problems involves writing down the mathematical problem in state-space-like representation using one of the space variables as time-like. First, system observability result for 3D boundary estimation problem is recalled in an infinite dimensional setting. Then, based on the observability result, the boundary estimation problem is decomposed into a set of independent 2D sub-problems. These 2D problems are then solved using an iterative observer to obtain the solution. Theoretical results are provided. The method is implemented numerically using finite difference discretization schemes. Numerical illustrations along with simulation results are provided.
The boundary element method applied to 3D magneto-electro-elastic dynamic problems
Igumnov, L. A.; Markov, I. P.; Kuznetsov, Iu A.
2017-11-01
Due to the coupling properties, the magneto-electro-elastic materials possess a wide number of applications. They exhibit general anisotropic behaviour. Three-dimensional transient analyses of magneto-electro-elastic solids can hardly be found in the literature. 3D direct boundary element formulation based on the weakly-singular boundary integral equations in Laplace domain is presented in this work for solving dynamic linear magneto-electro-elastic problems. Integral expressions of the three-dimensional fundamental solutions are employed. Spatial discretization is based on a collocation method with mixed boundary elements. Convolution quadrature method is used as a numerical inverse Laplace transform scheme to obtain time domain solutions. Numerical examples are provided to illustrate the capability of the proposed approach to treat highly dynamic problems.
Iterative observer based method for source localization problem for Poisson equation in 3D
Majeed, Muhammad Usman; Laleg-Kirati, Taous-Meriem
2017-01-01
A state-observer based method is developed to solve point source localization problem for Poisson equation in a 3D rectangular prism with available boundary data. The technique requires a weighted sum of solutions of multiple boundary data
3D Modeling and Simulation for Electromagnetic Non-Destructive Testing- Problems and Limitations
International Nuclear Information System (INIS)
Ilham Mukriz Zainal Abidin; Nurul Ain Ahmad Latif
2011-01-01
Non-Destructive Testing (NDT) plays a critical role in nuclear power plants (NPPs) for life cycle management; such testing requires specialists with various NDT related expertise with specific equipment. This paper will discuss the importance of 3D modeling and simulation for electromagnetic NDT for critical and complex components in terms of engineering reasoning and physical trials. Results from simulation are presented which show the link established between the measurements and information relating to defects, such as 3D shape, size and location, which facilitates not only forward problem but also inverse modeling involving experimental system specification and configuration; and pattern recognition for 3D defect information. Subsequently, the problems and limitations pertinent to 3D modeling and simulation are then highlighted and areas of improvement are discussed. (author)
Q-S synchronization in 3D Henon-like map and generalized Henon map via a scalar controller
International Nuclear Information System (INIS)
Yan Zhenya
2005-01-01
In this Letter, a generalized, systematic and automatic backstepping scheme is developed to investigate the Q-S synchronization of two identical 3a discrete-time dynamical systems and two different 3D discrete-time dynamical systems. With the aid of symbolic-numeric computation, we use the proposed scheme to illustrate chaos synchronization between two identical 3D generalized Henon map and Q-S synchronization between two different 3D generalized Henon map and Henon-like map via a scalar controller, respectively. Moreover numerical simulations are used to verify the effectiveness of the proposed scheme. In addition, the scheme can be also applied to investigate the tracking problem in the discrete-time systems and to generate automatically the scalar controller in computer with the aid of symbolic-numeric computation
A fast nonlinear conjugate gradient based method for 3D frictional contact problems
Zhao, J.; Vollebregt, E.A.H.; Oosterlee, C.W.
2014-01-01
This paper presents a fast numerical solver for a nonlinear constrained optimization problem, arising from a 3D frictional contact problem. It incorporates an active set strategy with a nonlinear conjugate gradient method. One novelty is to consider the tractions of each slip element in a polar
A fast nonlinear conjugate gradient based method for 3D concentrated frictional contact problems
J. Zhao (Jing); E.A.H. Vollebregt (Edwin); C.W. Oosterlee (Cornelis)
2015-01-01
htmlabstractThis paper presents a fast numerical solver for a nonlinear constrained optimization problem, arising from 3D concentrated frictional shift and rolling contact problems with dry Coulomb friction. The solver combines an active set strategy with a nonlinear conjugate gradient method. One
Reconstruction formula for a 3-d phaseless inverse scattering problem for the Schrodinger equation
Klibanov, Michael V.; Romanov, Vladimir G.
2014-01-01
The inverse scattering problem of the reconstruction of the unknown potential with compact support in the 3-d Schr\\"odinger equation is considered. Only the modulus of the scattering complex valued wave field is known, whereas the phase is unknown. It is shown that the unknown potential can be reconstructed via the inverse Radon transform. Therefore, a long standing problem posed in 1977 by K. Chadan and P.C. Sabatier in their book "Inverse Problems in Quantum Scattering Theory" is solved.
International Nuclear Information System (INIS)
Staraselski, Y; Brahme, A; Inal, K; Mishra, R K
2015-01-01
This paper presents the first application of three-dimensional (3D) cross-correlation microstructure reconstruction implemented for a representative volume element (RVE) to facilitate the microstructure engineering of materials. This has been accomplished by developing a new methodology for reconstructing 3D microstructure using experimental two-dimensional electron backscatter diffraction data. The proposed methodology is based on the analytical representation of the generalized form of the two-point correlation function—the distance-disorientation function (DDF). Microstructure reconstruction is accomplished by extending the simulated annealing techniques to perform three term reconstruction with a minimization of the DDF. The new 3D microstructure reconstruction algorithm is employed to determine the 3D RVE containing all of the relevant microstructure information for accurately computing the mechanical response of solids, especially when local microstructural variations influence the global response of the material as in the case of fracture initiation. (paper)
Analytical Lie-algebraic solution of a 3D sound propagation problem in the ocean
Energy Technology Data Exchange (ETDEWEB)
Petrov, P.S., E-mail: petrov@poi.dvo.ru [Il' ichev Pacific Oceanological Institute, 43 Baltiyskaya str., Vladivostok, 690041 (Russian Federation); Prants, S.V., E-mail: prants@poi.dvo.ru [Il' ichev Pacific Oceanological Institute, 43 Baltiyskaya str., Vladivostok, 690041 (Russian Federation); Petrova, T.N., E-mail: petrova.tn@dvfu.ru [Far Eastern Federal University, 8 Sukhanova str., 690950, Vladivostok (Russian Federation)
2017-06-21
The problem of sound propagation in a shallow sea with variable bottom slope is considered. The sound pressure field produced by a time-harmonic point source in such inhomogeneous 3D waveguide is expressed in the form of a modal expansion. The expansion coefficients are computed using the adiabatic mode parabolic equation theory. The mode parabolic equations are solved explicitly, and the analytical expressions for the modal coefficients are obtained using a Lie-algebraic technique. - Highlights: • A group-theoretical approach is applied to a problem of sound propagation in a shallow sea with variable bottom slope. • An analytical solution of this problem is obtained in the form of modal expansion with analytical expressions of the coefficients. • Our result is the only analytical solution of the 3D sound propagation problem with no translational invariance. • This solution can be used for the validation of the numerical propagation models.
Co-simulation coupling spectral/finite elements for 3D soil/structure interaction problems
Zuchowski, Loïc; Brun, Michael; De Martin, Florent
2018-05-01
The coupling between an implicit finite elements (FE) code and an explicit spectral elements (SE) code has been explored for solving the elastic wave propagation in the case of soil/structure interaction problem. The coupling approach is based on domain decomposition methods in transient dynamics. The spatial coupling at the interface is managed by a standard coupling mortar approach, whereas the time integration is dealt with an hybrid asynchronous time integrator. An external coupling software, handling the interface problem, has been set up in order to couple the FE software Code_Aster with the SE software EFISPEC3D.
Efficient solution of 3D Ginzburg-Landau problem for mesoscopic superconductors
International Nuclear Information System (INIS)
Pereira, Paulo J; Moshchalkov, Victor V; Chibotaru, Liviu F
2014-01-01
The recently proposed approach for the solution of Ginzburg-Landau (GL) problem for 2D samples of arbitrary shape is, in this article, extended over 3D samples having the shape of (i) a prism with arbitrary base and (ii) a solid of revolution with arbitrary profile. Starting from the set of Laplace operator eigenfunctions of a 2D object, we construct an approximation to or the exact eigenfunctions of the Laplace operator of a 3D structure by applying an extrusion or revolution to these solutions. This set of functions is used as the basis to construct the solutions of the linearized GL equation. These solutions are then used as basis for the non-linear GL equation much like the famous LCAO method. To solve the non-linear equation, we used the Newton-Raphson method starting from the solution of the linear equation, i.e., the nucleation distribution of superconducting condensate. The vector potential approximations typically used in 2D cases, i.e., considering it as corresponding to applied constant field, are in the 3D case harder to justify. For that reason, we use a locally corrected Nystrom method to solve the second Ginzburg-Landau equation. The complete solution of GL problem is then achieved by solving self-consistently both equations
A new general purpose event horizon finder for 3D numerical spacetimes
International Nuclear Information System (INIS)
Diener, Peter
2003-01-01
I present a new general purpose event horizon finder for full 3D numerical spacetimes. It works by evolving a complete null surface backwards in time. The null surface is described as the zero-level set of a scalar function, which in principle is defined everywhere. This description of the surface allows the surface, trivially, to change topology, making this event horizon finder able to handle numerical spacetimes where two (or more) black holes merge into a single final black hole
Narayan, Ramesh; Zhu, Yucong; Psaltis, Dimitrios; Saḑowski, Aleksander
2016-03-01
We describe Hybrid Evaluator for Radiative Objects Including Comptonization (HEROIC), an upgraded version of the relativistic radiative post-processor code HERO described in a previous paper, but which now Includes Comptonization. HEROIC models Comptonization via the Kompaneets equation, using a quadratic approximation for the source function in a short characteristics radiation solver. It employs a simple form of accelerated lambda iteration to handle regions of high scattering opacity. In addition to solving for the radiation field, HEROIC also solves for the gas temperature by applying the condition of radiative equilibrium. We present benchmarks and tests of the Comptonization module in HEROIC with simple 1D and 3D scattering problems. We also test the ability of the code to handle various relativistic effects using model atmospheres and accretion flows in a black hole space-time. We present two applications of HEROIC to general relativistic magnetohydrodynamics simulations of accretion discs. One application is to a thin accretion disc around a black hole. We find that the gas below the photosphere in the multidimensional HEROIC solution is nearly isothermal, quite different from previous solutions based on 1D plane parallel atmospheres. The second application is to a geometrically thick radiation-dominated accretion disc accreting at 11 times the Eddington rate. Here, the multidimensional HEROIC solution shows that, for observers who are on axis and look down the polar funnel, the isotropic equivalent luminosity could be more than 10 times the Eddington limit, even though the spectrum might still look thermal and show no signs of relativistic beaming.
International Nuclear Information System (INIS)
Lu Yanlin; Zhou Xiao; Qu Jiadi; Dou Yikang; He Yinbiao
2005-01-01
An efficient scheme, 3-D thermal weight function (TWF) method, and a novel numerical technique, multiple virtual crack extension (MVCE) technique, were developed for determination of histories of transient stress intensity factor (SIF) distributions along 3-D crack fronts of a body subjected to thermal shock. The TWF is a universal function, which is dependent only on the crack configuration and body geometry. TWF is independent of time during thermal shock, so the whole history of transient SIF distributions along crack fronts can be directly calculated through integration of the products of TWF and transient temperatures and temperature gradients. The repeated determinations of the distributions of stresses (or displacements) fields for individual time instants are thus avoided in the TWF method. An expression of the basic equation for the 3-D universal weight function method for Mode I in an isotropic elastic body is derived. This equation can also be derived from Bueckner-Rice's 3-D WF formulations in the framework of transformation strain. It can be understood from this equation that the so-called thermal WF is in fact coincident with the mechanical WF except for some constants of elasticity. The details and formulations of the MVCE technique are given for elliptical cracks. The MVCE technique possesses several advantages. The specially selected linearly independent VCE modes can directly be used as shape functions for the interpolation of unknown SIFs. As a result, the coefficient matrix of the final system of equations in the MVCE method is a triple-diagonal matrix and the values of the coefficients on the main diagonal are large. The system of equations has good numerical properties. The number of linearly independent VCE modes that can be introduced in a problem is unlimited. Complex situations in which the SIFs vary dramatically along crack fronts can be numerically well simulated by the MVCE technique. An integrated system of programs for solving the
Spherical cavity-expansion forcing function in PRONTO 3D for application to penetration problems
Energy Technology Data Exchange (ETDEWEB)
Warren, T.L.; Tabbara, M.R.
1997-05-01
In certain penetration events the primary mode of deformation of the target can be approximated by known analytical expressions. In the context of an analysis code, this approximation eliminates the need for modeling the target as well as the need for a contact algorithm. This technique substantially reduces execution time. In this spirit, a forcing function which is derived from a spherical-cavity expansion analysis has been implemented in PRONTO 3D. This implementation is capable of computing the structural and component responses of a projectile due to three dimensional penetration events. Sample problems demonstrate good agreement with experimental and analytical results.
A MATLAB Script for Solving 2D/3D Minimum Compliance Problems using Anisotropic Mesh Adaptation
DEFF Research Database (Denmark)
Jensen, Kristian Ejlebjerg
2017-01-01
We present a pure MATLAB implementation for solving 2D/3D compliance minimization problems using the density method. A filtered design variable with a minimum length is computed using a Helmholtz-type differential equation. The optimality criteria is used as optimizer and to avoid local minima we...... apply continuation of an exponent that controls the stiffness associated with intermediate design variables. We constrain the volume from above and use the implementation to show that optimizations with dynamic meshes can save significant amounts of computational time compared to fixed meshes without...
International Nuclear Information System (INIS)
Hadek, J.; Kral, P.; Macek, J.
2001-01-01
The paper gives a brief survey of the 6 th three-dimensional AER dynamic benchmark calculation results received with the codes DYN3D and RELAPS-3D at NRI Rez. This benchmark was defined at the 10 th AER Symposium. Its initiating event is a double ended break in the steam line of steam generator No. I in a WWER-440/213 plant at the end of the first fuel cycle and in hot full power conditions. Stationary and burnup calculations as well as tuning of initial state before the transient were performed with the code DYN3D. Transient calculations were made with the system code RELAPS-3D.The KASSETA library was used for the generation of reactor core neutronic parameters. The detailed six loops model of NPP Dukovany was adopted for the 6 th AER dynamic benchmark purposes. The RELAPS-3D full core neutronic model was connected with seven coolant channels thermal-hydraulic model of the core (Authors)
International Nuclear Information System (INIS)
Boman, R.; Papeleux, L.; Ponthot, J. P.
2007-01-01
In this paper, the Arbitrary Lagrangian Eulerian formalism is used to compute the steady state of a 2D metal cutting operation and a 3D U-shaped cold roll forming process. Compared to the Lagrangian case, this method allows the use of a refined mesh near the tools, leading to an accurate representation of the chip formation (metal cutting) and the bending of the sheet (roll forming) with a limited computational time. The main problem of this kind of simulation is the rezoning of the nodes on the free surfaces of the sheet. A modified iterative isoparametric smoother is used to manage this geometrically complex and CPU expensive task
Adaptive unified continuum FEM modeling of a 3D FSI benchmark problem.
Jansson, Johan; Degirmenci, Niyazi Cem; Hoffman, Johan
2017-09-01
In this paper, we address a 3D fluid-structure interaction benchmark problem that represents important characteristics of biomedical modeling. We present a goal-oriented adaptive finite element methodology for incompressible fluid-structure interaction based on a streamline diffusion-type stabilization of the balance equations for mass and momentum for the entire continuum in the domain, which is implemented in the Unicorn/FEniCS software framework. A phase marker function and its corresponding transport equation are introduced to select the constitutive law, where the mesh tracks the discontinuous fluid-structure interface. This results in a unified simulation method for fluids and structures. We present detailed results for the benchmark problem compared with experiments, together with a mesh convergence study. Copyright © 2016 John Wiley & Sons, Ltd.
Numerical modeling of time domain 3-D problems in accelerator physics
International Nuclear Information System (INIS)
Harfoush, F.A.; Jurgens, T.G.
1990-06-01
Time domain analysis is relevant in particle accelerators to study the electromagnetic field interaction of a moving source particle on a lagging test particle as the particles pass an accelerating cavity or some other structure. These fields are called wake fields. The travelling beam inside a beam pipe may undergo more complicated interactions with its environment due to the presence of other irregularities like wires, thin slots, joints and other types of obstacles. Analytical solutions of such problems is impossible and one has to resort to a numerical method. In this paper we present results of our first attempt to model these problems in 3-D using our finite difference time domain (FDTD) code. 10 refs., 9 figs
International Nuclear Information System (INIS)
Hassan, E M; Kalamkarov, A L; Georgiades, A V; Challagulla, K S
2009-01-01
A comprehensive micromechanical model for smart 3D composite structures reinforced with a periodic grid of generally orthotropic cylindrical reinforcements that also exhibit piezoelectric behavior is developed. The original boundary value problem characterizing the piezothermoelastic behavior of these structures is decoupled into a set of three simpler unit cell problems dealing, separately, with the elastic, piezoelectric and thermal expansion characteristics of the smart composite. The technique used is that of asymptotic homogenization and the solution of the unit cell problems permits determination of the effective elastic, piezoelectric and thermal expansion coefficients. The general orthotropy of the constituent materials is very important from the practical viewpoint and makes the analysis much more complicated. Several examples of practical interest are used to illustrate the work including smart 3D composites with cubic and conical embedded grids as well as diagonally reinforced smart structures. It is also shown in this work that in the limiting particular case of 2D grid-reinforced structures with isotropic reinforcements our results converge to earlier published results
Prigozhin, Leonid; Sokolovsky, Vladimir
2018-05-01
We consider the fast Fourier transform (FFT) based numerical method for thin film magnetization problems (Vestgården and Johansen 2012 Supercond. Sci. Technol. 25 104001), compare it with the finite element methods, and evaluate its accuracy. Proposed modifications of this method implementation ensure stable convergence of iterations and enhance its efficiency. A new method, also based on the FFT, is developed for 3D bulk magnetization problems. This method is based on a magnetic field formulation, different from the popular h-formulation of eddy current problems typically employed with the edge finite elements. The method is simple, easy to implement, and can be used with a general current–voltage relation; its efficiency is illustrated by numerical simulations.
Embedding SAS approach into conjugate gradient algorithms for asymmetric 3D elasticity problems
Energy Technology Data Exchange (ETDEWEB)
Chen, Hsin-Chu; Warsi, N.A. [Clark Atlanta Univ., GA (United States); Sameh, A. [Univ. of Minnesota, Minneapolis, MN (United States)
1996-12-31
In this paper, we present two strategies to embed the SAS (symmetric-and-antisymmetric) scheme into conjugate gradient (CG) algorithms to make solving 3D elasticity problems, with or without global reflexive symmetry, more efficient. The SAS approach is physically a domain decomposition scheme that takes advantage of reflexive symmetry of discretized physical problems, and algebraically a matrix transformation method that exploits special reflexivity properties of the matrix resulting from discretization. In addition to offering large-grain parallelism, which is valuable in a multiprocessing environment, the SAS scheme also has the potential for reducing arithmetic operations in the numerical solution of a reasonably wide class of scientific and engineering problems. This approach can be applied directly to problems that have global reflexive symmetry, yielding smaller and independent subproblems to solve, or indirectly to problems with partial symmetry, resulting in loosely coupled subproblems. The decomposition is achieved by separating the reflexive subspace from the antireflexive one, possessed by a special class of matrices A, A {element_of} C{sup n x n} that satisfy the relation A = PAP where P is a reflection matrix (symmetric signed permutation matrix).
Fall, Mandiaye; Boutami, Salim; Glière, Alain; Stout, Brian; Hazart, Jerome
2013-06-01
A combination of the multilevel fast multipole method (MLFMM) and boundary element method (BEM) can solve large scale photonics problems of arbitrary geometry. Here, MLFMM-BEM algorithm based on a scalar and vector potential formulation, instead of the more conventional electric and magnetic field formulations, is described. The method can deal with multiple lossy or lossless dielectric objects of arbitrary geometry, be they nested, in contact, or dispersed. Several examples are used to demonstrate that this method is able to efficiently handle 3D photonic scatterers involving large numbers of unknowns. Absorption, scattering, and extinction efficiencies of gold nanoparticle spheres, calculated by the MLFMM, are compared with Mie's theory. MLFMM calculations of the bistatic radar cross section (RCS) of a gold sphere near the plasmon resonance and of a silica coated gold sphere are also compared with Mie theory predictions. Finally, the bistatic RCS of a nanoparticle gold-silver heterodimer calculated with MLFMM is compared with unmodified BEM calculations.
3D overlapped grouping Ga for optimum 2D guillotine cutting stock problem
Directory of Open Access Journals (Sweden)
Maged R. Rostom
2014-09-01
Full Text Available The cutting stock problem (CSP is one of the significant optimization problems in operations research and has gained a lot of attention for increasing efficiency in industrial engineering, logistics and manufacturing. In this paper, new methodologies for optimally solving the cutting stock problem are presented. A modification is proposed to the existing heuristic methods with a hybrid new 3-D overlapped grouping Genetic Algorithm (GA for nesting of two-dimensional rectangular shapes. The objective is the minimization of the wastage of the sheet material which leads to maximizing material utilization and the minimization of the setup time. The model and its results are compared with real life case study from a steel workshop in a bus manufacturing factory. The effectiveness of the proposed approach is shown by comparing and shop testing of the optimized cutting schedules. The results reveal its superiority in terms of waste minimization comparing to the current cutting schedules. The whole procedure can be completed in a reasonable amount of time by the developed optimization program.
Häyrynen, Teppo; Osterkryger, Andreas Dyhl; de Lasson, Jakob Rosenkrantz; Gregersen, Niels
2017-09-01
Recently, an open geometry Fourier modal method based on a new combination of an open boundary condition and a non-uniform k-space discretization was introduced for rotationally symmetric structures, providing a more efficient approach for modeling nanowires and micropillar cavities [J. Opt. Soc. Am. A33, 1298 (2016)JOAOD61084-752910.1364/JOSAA.33.001298]. Here, we generalize the approach to three-dimensional (3D) Cartesian coordinates, allowing for the modeling of rectangular geometries in open space. The open boundary condition is a consequence of having an infinite computational domain described using basis functions that expand the whole space. The strength of the method lies in discretizing the Fourier integrals using a non-uniform circular "dartboard" sampling of the Fourier k space. We show that our sampling technique leads to a more accurate description of the continuum of the radiation modes that leak out from the structure. We also compare our approach to conventional discretization with direct and inverse factorization rules commonly used in established Fourier modal methods. We apply our method to a variety of optical waveguide structures and demonstrate that the method leads to a significantly improved convergence, enabling more accurate and efficient modeling of open 3D nanophotonic structures.
3D General Circulation Model of the Middle Atmosphere of Jupiter
Zube, Nicholas Gerard; Zhang, Xi; Li, Cheng; Le, Tianhao
2017-10-01
The characteristics of Jupiter’s large-scale stratospheric circulation remain largely unknown. Detailed distributions of temperature and photochemical species have been provided by recent observations [1], but have not yet been accurately reproduced by middle atmosphere general circulation models (GCM). Jupiter’s stratosphere and upper troposphere are influenced by radiative forcing from solar insolation and infrared cooling from hydrogen and hydrocarbons, as well as waves propagating from the underlying troposphere [2]. The relative significance of radiative and mechanical forcing on stratospheric circulation is still being debated [3]. Here we present a 3D GCM of Jupiter’s atmosphere with a correlated-k radiative transfer scheme. The simulation results are compared with observations. We analyze the impact of model parameters on the stratospheric temperature distribution and dynamical features. Finally, we discuss future tracer transport and gravity wave parameterization schemes that may be able to accurately simulate the middle atmosphere dynamics of Jupiter and other giant planets.[1] Kunde et al. 2004, Science 305, 1582.[2] Zhang et al. 2013a, EGU General Assembly, EGU2013-5797-2.[3] Conrath 1990, Icarus, 83, 255-281.
Ngom, Ndèye Fatou; Monga, Olivier; Ould Mohamed, Mohamed Mahmoud; Garnier, Patricia
2012-02-01
This paper focuses on the modeling of soil microstructures using generalized cylinders, with a specific application to pore space. The geometric modeling of these microstructures is a recent area of study, made possible by the improved performance of computed tomography techniques. X-scanners provide very-high-resolution 3D volume images ( 3-5μm) of soil samples in which pore spaces can be extracted by thresholding. However, in most cases, the pore space defines a complex volume shape that cannot be approximated using simple analytical functions. We propose representing this shape using a compact, stable, and robust piecewise approximation by means of generalized cylinders. This intrinsic shape representation conserves its topological and geometric properties. Our algorithm includes three main processing stages. The first stage consists in describing the volume shape using a minimum number of balls included within the shape, such that their union recovers the shape skeleton. The second stage involves the optimum extraction of simply connected chains of balls. The final stage copes with the approximation of each simply optimal chain using generalized cylinders: circular generalized cylinders, tori, cylinders, and truncated cones. This technique was applied to several data sets formed by real volume computed tomography soil samples. It was possible to demonstrate that our geometric representation supplied a good approximation of the pore space. We also stress the compactness and robustness of this method with respect to any changes affecting the initial data, as well as its coherence with the intuitive notion of pores. During future studies, this geometric pore space representation will be used to simulate biological dynamics.
Memory allocation and computations for Laplace’s equation of 3-D arbitrary boundary problems
Directory of Open Access Journals (Sweden)
Tsay Tswn-Syau
2017-01-01
Full Text Available Computation iteration schemes and memory allocation technique for finite difference method were presented in this paper. The transformed form of a groundwater flow problem in the generalized curvilinear coordinates was taken to be the illustrating example and a 3-dimensional second order accurate 19-point scheme was presented. Traditional element-by-element methods (e.g. SOR are preferred since it is simple and memory efficient but time consuming in computation. For efficient memory allocation, an index method was presented to store the sparse non-symmetric matrix of the problem. For computations, conjugate-gradient-like methods were reported to be computationally efficient. Among them, using incomplete Choleski decomposition as preconditioner was reported to be good method for iteration convergence. In general, the developed index method in this paper has the following advantages: (1 adaptable to various governing and boundary conditions, (2 flexible for higher order approximation, (3 independence of problem dimension, (4 efficient for complex problems when global matrix is not symmetric, (5 convenience for general sparse matrices, (6 computationally efficient in the most time consuming procedure of matrix multiplication, and (7 applicable to any developed matrix solver.
A novel numerical flux for the 3D Euler equations with general equation of state
Toro, Eleuterio F.
2015-09-30
Here we extend the flux vector splitting approach recently proposed in (E F Toro and M E Vázquez-Cendón. Flux splitting schemes for the Euler equations. Computers and Fluids. Vol. 70, Pages 1-12, 2012). The scheme was originally presented for the 1D Euler equations for ideal gases and its extension presented in this paper is threefold: (i) we solve the three-dimensional Euler equations on general meshes; (ii) we use a general equation of state; and (iii) we achieve high order of accuracy in both space and time through application of the semi-discrete ADER methodology on general meshes. The resulting methods are systematically assessed for accuracy, robustness and efficiency on a carefully selected suite of test problems. Formal high accuracy is assessed through convergence rates studies for schemes of up to 4th order of accuracy in both space and time on unstructured meshes.
A general 3-D nonlinear magnetostrictive constitutive model for soft ferromagnetic materials
International Nuclear Information System (INIS)
Zhou Haomiao; Zhou Youhe; Zheng Xiaojing; Ye Qiang; Wei Jing
2009-01-01
In this paper, a new general nonlinear magnetostrictive constitutive model is proposed for soft ferromagnetic materials, and it can predict magnetostrictive strain and magnetization curves under various pre-stresses. From the viewpoint of magnetic domain, it is based on the important physical fact that a nonlinear part of the elastic strain produced by magnetic domain wall motion under a pre-stress is responsible for the change of the maximum magnetostrictive strain in accordance with the pre-stress. Then the reduction of magnetostrictive strain from the maximum is caused by the domain rotation. Meanwhile, the magnetization under various pre-stresses in this model is introduced by magnetostrictive effect under the same pre-stress. A simplified 3-D model is put forward by means of linearizing the nonlinear function, i.e. the nonlinear part of the elastic strain produced by domain wall motion, and by using the quartic of magnetization to describe domain rotation. Besides, for the convenience of engineering applications, two-dimensional (plate or film) and one-dimensional (rod) models are also given for isotropic materials and their application ranges are discussed too. In comparison with the experimental data of Kuruzar and Jiles, it is found that this model can predict magnetostrictive strain and magnetization curves under various pre-stresses. The numerical simulation further illustrates that the new model can effectively describe the effects of the pre-stress or residual stress on the magnetization and magnetostrictive strain curves. Additionally, this model can be degenerated to the existing magnetostrictive constitutive model for giant magnetostrictive materials (GMM), i.e. a special soft ferromagnetic material
Energy Technology Data Exchange (ETDEWEB)
Leonard, P.J.; Lai, H.C.; Eastham, J.F.; Al-Akayshee, Q.H. [Univ. of Bath (United Kingdom)
1996-05-01
This paper describes an efficient scheme for incorporating multiple wire wound coils into 3D finite element models. The scheme is based on the magnetic scalar representation with an additional basis for each coil. There are no restrictions on the topology of coils with respect to ferromagnetic and conductor regions. Reduced scalar regions and cuts are automatically generated.
Vajdic, Stevan M.; Katz, Henry E.; Downing, Andrew R.; Brooks, Michael J.
1994-09-01
A 3D relational image matching/fusion algorithm is introduced. It is implemented in the domain of medical imaging and is based on Artificial Intelligence paradigms--in particular, knowledge base representation and tree search. The 2D reference and target images are selected from 3D sets and segmented into non-touching and non-overlapping regions, using iterative thresholding and/or knowledge about the anatomical shapes of human organs. Selected image region attributes are calculated. Region matches are obtained using a tree search, and the error is minimized by evaluating a `goodness' of matching function based on similarities of region attributes. Once the matched regions are found and the spline geometric transform is applied to regional centers of gravity, images are ready for fusion and visualization into a single 3D image of higher clarity.
Chen, Meixiong; Yuan, Jie; Long, Xingwu; Kang, Zhenglong; Wang, Zhiguo; Li, Yingying
2013-12-01
A general beam position controlling method for 3D optical systems based on the method of solving ray matrix equations has been proposed in this paper. As a typical 3D optical system, nonplanar ring resonator of Zero-Lock Laser Gyroscopes has been chosen as an example to show its application. The total mismatching error induced by Faraday-wedge in nonplanar ring resonator has been defined and eliminated quite accurately with the error less than 1 μm. Compared with the method proposed in Ref. [14], the precision of the beam position controlling has been improved by two orders of magnitude. The novel method can be used to implement automatic beam position controlling in 3D optical systems with servo circuit. All those results have been confirmed by related alignment experiments. The results in this paper are important for beam controlling, ray tracing, cavity design and alignment in 3D optical systems.
Directory of Open Access Journals (Sweden)
H. Tashakkori
2016-10-01
Full Text Available Search and rescue procedures for indoor environments are quite complicated due to the fact that much of the indoor information is unavailable to rescuers before physical entrance to the incident scene. Thus, decision making regarding the number of crew required and the way they should be dispatched in the building considering the various access points and complexities in the buildings in order to cover the search area in minimum time is dependent on prior knowledge and experience of the emergency commanders. Hence, this paper introduces the Search and Rescue Problem (SRP which aims at finding best search and rescue routes that minimize the overall search time in the buildings. 3D BIM-oriented indoor GIS is integrated in the indoor route graph to find accurate routes based on the building geometric and semantic information. An Ant Colony Based Algorithm is presented that finds the number of first responders required and their individual routes to search all rooms and points of interest inside the building to minimize the overall time spent by all rescuers inside the disaster area. The evaluation of the proposed model for a case study building shows a significant improve in search and rescue time which will lead to a higher chance of saving lives and less exposure of emergency crew to danger.
Tashakkori, H.; Rajabifard, A.; Kalantari, M.
2016-10-01
Search and rescue procedures for indoor environments are quite complicated due to the fact that much of the indoor information is unavailable to rescuers before physical entrance to the incident scene. Thus, decision making regarding the number of crew required and the way they should be dispatched in the building considering the various access points and complexities in the buildings in order to cover the search area in minimum time is dependent on prior knowledge and experience of the emergency commanders. Hence, this paper introduces the Search and Rescue Problem (SRP) which aims at finding best search and rescue routes that minimize the overall search time in the buildings. 3D BIM-oriented indoor GIS is integrated in the indoor route graph to find accurate routes based on the building geometric and semantic information. An Ant Colony Based Algorithm is presented that finds the number of first responders required and their individual routes to search all rooms and points of interest inside the building to minimize the overall time spent by all rescuers inside the disaster area. The evaluation of the proposed model for a case study building shows a significant improve in search and rescue time which will lead to a higher chance of saving lives and less exposure of emergency crew to danger.
A general synthesis strategy for the multifunctional 3D polypyrrole foam of thin 2D nanosheets
Xue, Jiangli; Mo, Maosong; Liu, Zhuming; Ye, Dapeng; Cheng, Zhihua; Xu, Tong; Qu, Liangti
2018-05-01
A 3D macroporous conductive polymer foam of thin 2D polypyrrole (PPy) nanosheets is developed by adopting a novel intercalation of guest (monomer Py) between the layers of the lamellar host (3D vanadium oxide foam) template-replication strategy. The 3D PPy foam of thin 2D nanosheets exhibits diverse functions including reversible compressibility, shape memory, absorption/adsorption and mechanically deformable supercapacitor characteristics. The as-prepared 3D PPy foam of thin nanosheets is highly light weight with a density of 12 mg·cm-3 which can bear the large compressive strain up to 80% whether in wet or dry states; and can absorb organic solutions or extract dye molecules fast and efficiently. In particular, the PPy nanosheet-based foamas a mechanically deformable electrode material for supercapacitors exhibits high specific capacitance of 70 F·g-1 at a fast charge-discharge rate of 50 mA·g-1, superior to that of any other typical pure PPy-based capacitor. We envision that the strategy presented here should be applicable to fabrication of a wide variety of organic polymer foams and hydrogels of low-dimensional nanostructures and even inorganic foams and hydrogels of low-dimensional nanostructures, and thus allow for exploration of their advanced physical and chemical properties.
DEFF Research Database (Denmark)
Häyrynen, Teppo; Østerkryger, Andreas Dyhl; de Lasson, Jakob Rosenkrantz
2017-01-01
Recently, an open geometry Fourier modal method based on a new combination ofan open boundary condition and a non-uniform $k$-space discretization wasintroduced for rotationally symmetric structures providing a more efficientapproach for modeling nanowires and micropillar cavities [J. Opt. Soc. A...... moreaccurate and efficient modeling of open 3D nanophotonic structures....
International Nuclear Information System (INIS)
Jayaraman, Jambunatha; Lima Rodrigues, R. de
1994-01-01
In the context of the 3 D generalized SUSY model oscillator Hamiltonian of Celka and Hussin (CH), a generalized Dirac oscillator interaction is studied, that leads, in the non-relativistic limit considered for both signs of energy, to the CH's generalized 3 D SUSY oscillator. The relevance of this interaction to the CH's SUSY model and the SUSY breaking dependent on the Wigner parameter is brought out. (author). 6 refs
Mansour , Salwa; Muhieddine , Mohamad; Canot , Édouard; March , Ramiro J.
2014-01-01
International audience; This paper is motivated by the studies of agricultural and archaeological soils. We introduce a numerical strategy in 3D axisymmetric coordinate system to estimate the thermophysical properties of a saturated porous medium (volumetric heat capacity, thermal conductivity and porosity) where a phase change problem (liquid/vapor) appears due to strong heating. The estimation of these thermophysical properties is done by inverse problem knowing the heating curves at select...
General 3D Lumped Thermal Model with Various Boundary Conditions for High Power IGBT Modules
DEFF Research Database (Denmark)
Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede
2016-01-01
Accurate thermal dynamics modeling of high power Insulated Gate Bipolar Transistor (IGBT) modules is important information for the reliability analysis and thermal design of power electronic systems. However, the existing thermal models have their limits to correctly predict these complicated...... thermal behaviors in the IGBTs. In this paper, a new three-dimensional (3D) lumped thermal model is proposed, which can easily be characterized from Finite Element Methods (FEM) based simulation and acquire the thermal distribution in critical points. Meanwhile the boundary conditions including...... the cooling system and power losses are modeled in the 3D thermal model, which can be adapted to different real field applications of power electronic converters. The accuracy of the proposed thermal model is verified by experimental results....
A 3D moisture-stress FEM analysis for time dependent problems in timber structures
Fortino, Stefania; Mirianon, Florian; Toratti, Tomi
2009-11-01
This paper presents a 3D moisture-stress numerical analysis for timber structures under variable humidity and load conditions. An orthotropic viscoelastic-mechanosorptive material model is specialized on the basis of previous models. Both the constitutive model and the equations needed to describe the moisture flow across the structure are implemented into user subroutines of the Abaqus finite element code and a coupled moisture-stress analysis is performed for several types of mechanical loads and moisture changes. The presented computational approach is validated by analyzing some wood tests described in the literature and comparing the computational results with the reported experimental data.
International Nuclear Information System (INIS)
Bencik, M.; Hadek, J.
2011-01-01
The paper gives a brief survey of the seventh three-dimensional AER dynamic benchmark calculation results received with the codes DYN3D and RELAP5-3D at Nuclear Research Institute Rez. This benchmark was defined at the twentieth AER Symposium in Hanassari (Finland). It is focused on investigation of transient behaviour in a WWER-440 nuclear power plant. Its initiating event is opening of the main isolation valve and re-connection of the loop with its main circulation pump in operation. The WWER-440 plant is at the end of the first fuel cycle and in hot full power conditions. Stationary and burnup calculations were performed with the code DYN3D. Transient calculation was made with the system code RELAP5-3D. The two-group homogenized cross sections library HELGD05 created by HELIOS code was used for the generation of reactor core neutronic parameters. The detailed six loops model of NPP Dukovany was adopted for the seventh AER dynamic benchmark purposes. The RELAP5-3D full core neutronic model was coupled with 49 core thermal-hydraulic channels and 8 reflector channels connected with the three-dimensional model of the reactor vessel. The detailed nodalization of reactor downcomer, lower and upper plenum was used. Mixing in lower and upper plenum was simulated. The first part of paper contains a brief characteristic of RELAP5-3D system code and a short description of NPP input deck and reactor core model. The second part shows the time dependencies of important global and local parameters. (Authors)
International Nuclear Information System (INIS)
Xu Mingyu; Lin Tengjiao; Li Runfang; Du Xuesong; Li Shuian; Yang Yu
2005-01-01
There are some complex operating cases such as high temperature and high pressure during the operating process of nuclear reactor pressure vessel. It is necessary to carry out mechanical analysis and experimental investigation for its sealing ability. On the basis of the self-developed program for 3-D transient sealing analysis for nuclear reactor pressure vessel, some specific measures are presented to enhance the calculation efficiency in several aspects such as the non-linear solution of elasto-plastic problem, the mixed solution algorithm for contact problem as well as contract heat transfer problem and linear equation set solver. The 3-D transient sealing analysis program is amended and complemented, with which the sealing analysis result of the pressure vessel model can be obtained. The calculation results have good regularity and the calculation efficiency is twice more than before. (authors)
TRIO a general computer code for reactor 3-D flows analysis. Application to a LMFBR hot plenum
International Nuclear Information System (INIS)
Magnaud, J.P.; Rouzaud, P.
1985-09-01
TRIO is a code developed at CEA to investigate general incompressible 2D and 3D viscous flows. Two calculations are presented: the lid driven cubic cavity at Re=400; steady state (velocity and temperature field) of a LMFBR hot plenum, carried out in order to prepare the calculation of a cold shock consecutive to a reactor scram. 8 refs., 26 figs.
Directory of Open Access Journals (Sweden)
Slavcheva Galina Stanislavovna
2018-06-01
Full Text Available The paper considers the problem of creating a wider class of building materials used for 3D printing. From the point of view of classical rheology of disperse systems, the application of 3D printing technology in construction has been analyzed. Theoretical analysis of the models of rheological behavior is performed according to state of their structure and the dynamic of the 3D printing processes such as mixing, pumping, extrusion, multilayer casting and structural built-up in the printing layers. The main factors and criteria for the stability of heterogeneous disperse systems in dynamic and static 3D printing processes have been identified. The general scientific concept for optimization of admixtures for 3D printable materials has been developed in terms of viscosity, consistency, and parameters of flocculation and structural built-up. The technological tools to control rheological behavior of visco-plastic admixtures are identified in all stages of 3D printing. The relevant considerations include the concentration, size, morphology, chemical and mineralogical composition, the physical and chemical activity of the solid phase’s surface, and the ionic composition, viscosity, and density of the liquid phase. It is shown that the practical engineering solutions to control the rheology, structure formation, properties of 3D printing admixtures and materials must be based on traditional factors as well as with the use of «nano» tools. According to the nanotechnological principle «bottom-up», a set of «nano» tools is proposed to control such admixture properties as extrudability, formability, and buildability. In conclusion the scientific and technical tasks to be researched have been formulated.
On the Critical One Component Regularity for 3-D Navier-Stokes System: General Case
Chemin, Jean-Yves; Zhang, Ping; Zhang, Zhifei
2017-06-01
Let us consider initial data {v_0} for the homogeneous incompressible 3D Navier-Stokes equation with vorticity belonging to {L^{3/2}\\cap L^2}. We prove that if the solution associated with {v_0} blows up at a finite time {T^\\star}, then for any p in {]4,∞[}, and any unit vector e of {R^3}, the L p norm in time with value in \\dot{H}^{1/2 + 2/p } of {(v|e)_{R^3}} blows up at {T^\\star}.
Automatic contact algorithm in ppercase[dyna3d] for crashworthiness and impact problems
International Nuclear Information System (INIS)
Whirley, Robert G.; Engelmann, Bruce E.
1994-01-01
This paper presents a new approach for the automatic definition and treatment of mechanical contact in explicit non-linear finite element analysis. Automatic contact offers the benefits of significantly reduced model construction time and fewer opportunities for user error, but faces significant challenges in reliability and computational costs. Key aspects of the proposed new method include automatic identification of adjacent and opposite surfaces in the global search phase, and the use of a well-defined surface normal which allows a consistent treatment of shell intersection and corner contact conditions without adhoc rules. The paper concludes with three examples which illustrate the performance of the newly proposed algorithm in the public ppercase[dyna3d] code. ((orig.))
International Nuclear Information System (INIS)
Kılıç, Emre; Eibert, Thomas F.
2015-01-01
An approach combining boundary integral and finite element methods is introduced for the solution of three-dimensional inverse electromagnetic medium scattering problems. Based on the equivalence principle, unknown equivalent electric and magnetic surface current densities on a closed surface are utilized to decompose the inverse medium problem into two parts: a linear radiation problem and a nonlinear cavity problem. The first problem is formulated by a boundary integral equation, the computational burden of which is reduced by employing the multilevel fast multipole method (MLFMM). Reconstructed Cauchy data on the surface allows the utilization of the Lorentz reciprocity and the Poynting's theorems. Exploiting these theorems, the noise level and an initial guess are estimated for the cavity problem. Moreover, it is possible to determine whether the material is lossy or not. In the second problem, the estimated surface currents form inhomogeneous boundary conditions of the cavity problem. The cavity problem is formulated by the finite element technique and solved iteratively by the Gauss–Newton method to reconstruct the properties of the object. Regularization for both the first and the second problems is achieved by a Krylov subspace method. The proposed method is tested against both synthetic and experimental data and promising reconstruction results are obtained
Energy Technology Data Exchange (ETDEWEB)
Kılıç, Emre, E-mail: emre.kilic@tum.de; Eibert, Thomas F.
2015-05-01
An approach combining boundary integral and finite element methods is introduced for the solution of three-dimensional inverse electromagnetic medium scattering problems. Based on the equivalence principle, unknown equivalent electric and magnetic surface current densities on a closed surface are utilized to decompose the inverse medium problem into two parts: a linear radiation problem and a nonlinear cavity problem. The first problem is formulated by a boundary integral equation, the computational burden of which is reduced by employing the multilevel fast multipole method (MLFMM). Reconstructed Cauchy data on the surface allows the utilization of the Lorentz reciprocity and the Poynting's theorems. Exploiting these theorems, the noise level and an initial guess are estimated for the cavity problem. Moreover, it is possible to determine whether the material is lossy or not. In the second problem, the estimated surface currents form inhomogeneous boundary conditions of the cavity problem. The cavity problem is formulated by the finite element technique and solved iteratively by the Gauss–Newton method to reconstruct the properties of the object. Regularization for both the first and the second problems is achieved by a Krylov subspace method. The proposed method is tested against both synthetic and experimental data and promising reconstruction results are obtained.
Problem Solving with General Semantics.
Hewson, David
1996-01-01
Discusses how to use general semantics formulations to improve problem solving at home or at work--methods come from the areas of artificial intelligence/computer science, engineering, operations research, and psychology. (PA)
A Direct Numerical Reconstruction Algorithm for the 3D Calderón Problem
DEFF Research Database (Denmark)
Delbary, Fabrice; Hansen, Per Christian; Knudsen, Kim
2011-01-01
In three dimensions Calderón's problem was addressed and solved in theory in the 1980s in a series of papers, but only recently the numerical implementation of the algorithm was initiated. The main ingredients in the solution of the problem are complex geometrical optics solutions to the conducti...
International Nuclear Information System (INIS)
Capilla, M.; Talavera, C.F.; Ginestar, D.; Verdú, G.
2012-01-01
Highlights: ► The multidimensional P L approximation to the nuclear transport equation is reviewed. ► A nodal collocation method is developed for the spatial discretization of P L equations. ► Advantages of the method are lower dimension and good characterists of the associated algebraic eigenvalue problem. ► The P L nodal collocation method is implemented into the computer code SHNC. ► The SHNC code is verified with 2D and 3D benchmark eigenvalue problems from Takeda and Ikeda, giving satisfactory results. - Abstract: P L equations are classical approximations to the neutron transport equations, which are obtained expanding the angular neutron flux in terms of spherical harmonics. These approximations are useful to study the behavior of reactor cores with complex fuel assemblies, for the homogenization of nuclear cross-sections, etc., and most of these applications are in three-dimensional (3D) geometries. In this work, we review the multi-dimensional P L equations and describe a nodal collocation method for the spatial discretization of these equations for arbitrary odd order L, which is based on the expansion of the spatial dependence of the fields in terms of orthonormal Legendre polynomials. The performance of the nodal collocation method is studied by means of obtaining the k eff and the stationary power distribution of several 3D benchmark problems. The solutions are obtained are compared with a finite element method and a Monte Carlo method.
Bouallègue, Fayçal Ben; Crouzet, Jean-François; Comtat, Claude; Fourcade, Marjolaine; Mohammadi, Bijan; Mariano-Goulart, Denis
2007-07-01
This paper presents an extended 3-D exact rebinning formula in the Fourier space that leads to an iterative reprojection algorithm (iterative FOREPROJ), which enables the estimation of unmeasured oblique projection data on the basis of the whole set of measured data. In first approximation, this analytical formula also leads to an extended Fourier rebinning equation that is the basis for an approximate reprojection algorithm (extended FORE). These algorithms were evaluated on numerically simulated 3-D positron emission tomography (PET) data for the solution of the truncation problem, i.e., the estimation of the missing portions in the oblique projection data, before the application of algorithms that require complete projection data such as some rebinning methods (FOREX) or 3-D reconstruction algorithms (3DRP or direct Fourier methods). By taking advantage of all the 3-D data statistics, the iterative FOREPROJ reprojection provides a reliable alternative to the classical FOREPROJ method, which only exploits the low-statistics nonoblique data. It significantly improves the quality of the external reconstructed slices without loss of spatial resolution. As for the approximate extended FORE algorithm, it clearly exhibits limitations due to axial interpolations, but will require clinical studies with more realistic measured data in order to decide on its pertinence.
3D Reconnection and SEP Considerations in the CME-Flare Problem
Moschou, S. P.; Cohen, O.; Drake, J. J.; Sokolov, I.; Borovikov, D.; Alvarado Gomez, J. D.; Garraffo, C.
2017-12-01
Reconnection is known to play a major role in particle acceleration in both solar and astrophysical regimes, yet little is known about its connection with the global scales and its comparative contribution in the generation of SEPs with respect to other acceleration mechanisms, such as the shock at a fast CME front, in the presence of a global structure such as a CME. Coupling efforts, combining both particle and global scales, are necessary to answer questions about the fundamentals of the energetic processes evolved. We present such a coupling modeling effort that looks into particle acceleration through reconnection in a self-consistent CME-flare model in both particle and fluid regimes. Of special interest is the supra-thermal component of the acceleration due to the reconnection that will at a later time interact colliding with the solar atmospheric material of the more dense chromospheric layer and radiate in hard X- and γ-rays for super-thermal electrons and protons respectively. Two cutting edge computational codes are used to capture the global CME and flare dynamics, specifically a two fluid MHD code and a 3D PIC code for the flare scales. Finally, we are connecting the simulations with current observations in different wavelengths in an effort to shed light to the unified CME-flare picture.
Lattice Boltzmann Model of 3D Multiphase Flow in Artery Bifurcation Aneurysm Problem
Directory of Open Access Journals (Sweden)
Aizat Abas
2016-01-01
Full Text Available This paper simulates and predicts the laminar flow inside the 3D aneurysm geometry, since the hemodynamic situation in the blood vessels is difficult to determine and visualize using standard imaging techniques, for example, magnetic resonance imaging (MRI. Three different types of Lattice Boltzmann (LB models are computed, namely, single relaxation time (SRT, multiple relaxation time (MRT, and regularized BGK models. The results obtained using these different versions of the LB-based code will then be validated with ANSYS FLUENT, a commercially available finite volume- (FV- based CFD solver. The simulated flow profiles that include velocity, pressure, and wall shear stress (WSS are then compared between the two solvers. The predicted outcomes show that all the LB models are comparable and in good agreement with the FVM solver for complex blood flow simulation. The findings also show minor differences in their WSS profiles. The performance of the parallel implementation for each solver is also included and discussed in this paper. In terms of parallelization, it was shown that LBM-based code performed better in terms of the computation time required.
Summary of Documentation for DYNA3D-ParaDyn's Software Quality Assurance Regression Test Problems
Energy Technology Data Exchange (ETDEWEB)
Zywicz, Edward [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2016-08-18
The Software Quality Assurance (SQA) regression test suite for DYNA3D (Zywicz and Lin, 2015) and ParaDyn (DeGroot, et al., 2015) currently contains approximately 600 problems divided into 21 suites, and is a required component of ParaDyn’s SQA plan (Ferencz and Oliver, 2013). The regression suite allows developers to ensure that software modifications do not unintentionally alter the code response. The entire regression suite is run prior to permanently incorporating any software modification or addition. When code modifications alter test problem results, the specific cause must be determined and fully understood before the software changes and revised test answers can be incorporated. The regression suite is executed on LLNL platforms using a Python script and an associated data file. The user specifies the DYNA3D or ParaDyn executable, number of processors to use, test problems to run, and other options to the script. The data file details how each problem and its answer extraction scripts are executed. For each problem in the regression suite there exists an input deck, an eight-processor partition file, an answer file, and various extraction scripts. These scripts assemble a temporary answer file in a specific format from the simulation results. The temporary and stored answer files are compared to a specific level of numerical precision, and when differences are detected the test problem is flagged as failed. Presently, numerical results are stored and compared to 16 digits. At this accuracy level different processor types, compilers, number of partitions, etc. impact the results to various degrees. Thus, for consistency purposes the regression suite is run with ParaDyn using 8 processors on machines with a specific processor type (currently the Intel Xeon E5530 processor). For non-parallel regression problems, i.e., the two XFEM problems, DYNA3D is used instead. When environments or platforms change, executables using the current source code and the new
Bulat, Adrian; Tzimiropoulos, Georgios
2017-01-01
This paper investigates how far a very deep neural network is from attaining close to saturating performance on existing 2D and 3D face alignment datasets. To this end, we make the following 5 contributions: (a) we construct, for the first time, a very strong baseline by combining a state-of-the-art architecture for landmark localization with a state-of-the-art residual block, train it on a very large yet synthetically expanded 2D facial landmark dataset and finally evaluate it on all other 2...
A novel numerical flux for the 3D Euler equations with general equation of state
Toro, Eleuterio F.; Castro, Cristó bal E.; Bok Jik, Lee
2015-01-01
Euler equations for ideal gases and its extension presented in this paper is threefold: (i) we solve the three-dimensional Euler equations on general meshes; (ii) we use a general equation of state; and (iii) we achieve high order of accuracy in both
E.J. Spee (Edwin); P.M. de Zeeuw (Paul); J.G. Verwer (Jan); J.G. Blom (Joke); W. Hundsdorfer (Willem)
1996-01-01
textabstractAtmospheric air quality modeling relies in part on numerical simulation. Required numerical simulations are often hampered by lack of computer capacity and computational speed. This problem is most severe in the field of global modeling where transport and exchange of trace constituents
International Nuclear Information System (INIS)
Meneses, Anderson Alvarenga de Moura; Araujo, Lenilson Moreira; Nast, Fernando Nogueira; Da Silva, Patrick Vasconcelos; Schirru, Roberto
2018-01-01
Highlights: •Metaheuristics were applied to Loading Pattern Optimization problems and compared. •The problems are based on data of the benchmarks IAEA and BIBLIS. •The metaheuristics compared were PSO, Cross-Entropy, PBIL and Artificial Bee Colony. •Angra 1 NPP data were also used for further comparison of the algorithms. -- Abstract: The Loading Pattern Optimization (LPO) of a Nuclear Power Plant (NPP), or in-core fuel management optimization, is a real-world and prominent problem in Nuclear Engineering with the goal of finding an optimal (or near-optimal) Loading Pattern (LP), in terms of energy production, within adequate safety margins. Most of the reactor models used in the LPO problem are particular cases, such as research or power reactors with technical data that cannot be made available for several reasons, which makes the reproducibility of tests unattainable. In the present article we report the results of LPO of problems based upon reactor physics benchmarks. Since such data are well-known and widely available in the literature, it is possible to reproduce tests for comparison of techniques. We performed the LPO with the data of the benchmarks IAEA-3D and BIBLIS-2D. The Reactor Physics code RECNOD, which was used in previous works for the optimization of Angra 1 NPP in Brazil, was also used for further comparison. Four Optimization Metaheuristics (OMHs) were applied to those problems: Particle Swarm Optimization (PSO), Cross-Entropy algorithm (CE), Artificial Bee Colony (ABC) and Population-Based Incremental Learning (PBIL). For IAEA-3D, the best algorithm was the ABC. For BIBLIS-2D, PBIL was the best OMH. For Angra 1 / RECNOD optimization problem, PBIL, ABC and CE were the best OMHs.
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.
International Nuclear Information System (INIS)
Mair, H.D.; Ciorau, P.; Owen, D.; Hazelton, T.; Dunning, G.
2000-01-01
Two ultrasonic simulation packages: Imagine 3D and SIMSCAN have specifically been developed to solve the inverse problem for blade root and rotor steeple of low-pressure turbine. The software was integrated with the 3D drawing of the inspected parts, and with the dimensions of linear phased-array probes. SIMSCAN simulates the inspection scenario in both optional conditions: defect location and probe movement/refracted angle range. The results are displayed into Imagine 3-D, with a variety of options: rendering, display 1:1, grid, generated UT beam. The results are very useful for procedure developer, training and to optimize the phased-array probe inspection sequence. A spreadsheet is generated to correlate the defect coordinates with UT data (probe position, skew and refracted angle, UT path, and probe movement). The simulation models were validated during experimental work with phased-array systems. The accuracy in probe position is ±1 mm, and the refracted/skew angle is within ±0.5 deg. . Representative examples of phased array focal laws/probe movement for a specific defect location, are also included
Perturbation-polynomial expansion formulation of 3-D eddy current problems
International Nuclear Information System (INIS)
Yeh, H.T.
1977-01-01
A pulsed magnetic field is required in Tokamak fusion machines. Eddy currents produced by the pulsed field may produce undesirable effects, e.g., in the mechanical loading of the vacuum vessel, heating in the magnet and structure, and field ripple in the plasma region. A method has been developed earlier to calculate the eddy current produced in a thin object by the linear ramping of a magnetic dipole. We report here extension of the method to calculate the eddy current induced in three-dimensional objects and by pulse coils of general shape. Examples are given
3D Discrete element approach to the problem on abutment pressure in a gently dipping coal seam
Klishin, S. V.; Revuzhenko, A. F.
2017-09-01
Using the discrete element method, the authors have carried out 3D implementation of the problem on strength loss in surrounding rock mass in the vicinity of a production heading and on abutment pressure in a gently dripping coal seam. The calculation of forces at the contacts between particles accounts for friction, rolling resistance and viscosity. Between discrete particles modeling coal seam, surrounding rock mass and broken rocks, an elastic connecting element is introduced to allow simulating coherent materials. The paper presents the kinematic patterns of rock mass deformation, stresses in particles and the graph of the abutment pressure behavior in the coal seam.
A Generalized FDM for solving the Poisson's Equation on 3D Irregular Domains
Directory of Open Access Journals (Sweden)
J. Izadian
2014-01-01
Full Text Available In this paper a new method for solving the Poisson's equation with Dirichlet conditions on irregular domains is presented. For this purpose a generalized finite differences method is applied for numerical differentiation on irregular meshes. Three examples on cylindrical and spherical domains are considered. The numerical results are compared with analytical solution. These results show the performance and efficiency of the proposed method.
Energy Technology Data Exchange (ETDEWEB)
Shu, Yu-Chen, E-mail: ycshu@mail.ncku.edu.tw [Department of Mathematics, National Cheng Kung University, Tainan 701, Taiwan (China); Mathematics Division, National Center for Theoretical Sciences (South), Tainan 701, Taiwan (China); Chern, I-Liang, E-mail: chern@math.ntu.edu.tw [Department of Applied Mathematics, National Chiao Tung University, Hsin Chu 300, Taiwan (China); Department of Mathematics, National Taiwan University, Taipei 106, Taiwan (China); Mathematics Division, National Center for Theoretical Sciences (Taipei Office), Taipei 106, Taiwan (China); Chang, Chien C., E-mail: mechang@iam.ntu.edu.tw [Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan (China); Department of Mathematics, National Taiwan University, Taipei 106, Taiwan (China)
2014-10-15
Most elliptic interface solvers become complicated for complex interface problems at those “exceptional points” where there are not enough neighboring interior points for high order interpolation. Such complication increases especially in three dimensions. Usually, the solvers are thus reduced to low order accuracy. In this paper, we classify these exceptional points and propose two recipes to maintain order of accuracy there, aiming at improving the previous coupling interface method [26]. Yet the idea is also applicable to other interface solvers. The main idea is to have at least first order approximations for second order derivatives at those exceptional points. Recipe 1 is to use the finite difference approximation for the second order derivatives at a nearby interior grid point, whenever this is possible. Recipe 2 is to flip domain signatures and introduce a ghost state so that a second-order method can be applied. This ghost state is a smooth extension of the solution at the exceptional point from the other side of the interface. The original state is recovered by a post-processing using nearby states and jump conditions. The choice of recipes is determined by a classification scheme of the exceptional points. The method renders the solution and its gradient uniformly second-order accurate in the entire computed domain. Numerical examples are provided to illustrate the second order accuracy of the presently proposed method in approximating the gradients of the original states for some complex interfaces which we had tested previous in two and three dimensions, and a real molecule ( (1D63)) which is double-helix shape and composed of hundreds of atoms.
Energy Technology Data Exchange (ETDEWEB)
Delbos, F.
2004-11-01
Reflexion tomography allows the determination of a subsurface velocity model from the travel times of seismic waves. The introduction of a priori information in this inverse problem can lead to the resolution of a constrained non-linear least-squares problem. The goal of the thesis is to improve the resolution techniques of this optimization problem, whose main difficulties are its ill-conditioning, its large scale and an expensive cost function in terms of CPU time. Thanks to a detailed study of the problem and to numerous numerical experiments, we justify the use of a sequential quadratic programming method, in which the tangential quadratic programs are solved by an original augmented Lagrangian method. We show the global linear convergence of the latter. The efficiency and robustness of the approach are demonstrated on several synthetic examples and on two real data cases. (author)
Energy Technology Data Exchange (ETDEWEB)
Delbos, F
2004-11-01
Reflexion tomography allows the determination of a subsurface velocity model from the travel times of seismic waves. The introduction of a priori information in this inverse problem can lead to the resolution of a constrained non-linear least-squares problem. The goal of the thesis is to improve the resolution techniques of this optimization problem, whose main difficulties are its ill-conditioning, its large scale and an expensive cost function in terms of CPU time. Thanks to a detailed study of the problem and to numerous numerical experiments, we justify the use of a sequential quadratic programming method, in which the tangential quadratic programs are solved by an original augmented Lagrangian method. We show the global linear convergence of the latter. The efficiency and robustness of the approach are demonstrated on several synthetic examples and on two real data cases. (author)
Chu, Chunlei
2009-01-01
We analyze the dispersion properties and stability conditions of the high‐order convolutional finite difference operators and compare them with the conventional finite difference schemes. We observe that the convolutional finite difference method has better dispersion properties and becomes more efficient than the conventional finite difference method with the increasing order of accuracy. This makes the high‐order convolutional operator a good choice for anisotropic elastic wave simulations on rotated staggered grids since its enhanced dispersion properties can help to suppress the numerical dispersion error that is inherent in the rotated staggered grid structure and its efficiency can help us tackle 3D problems cost‐effectively.
International Nuclear Information System (INIS)
Gado, J.
1986-02-01
The four group, 2D and 3D hexagonal geometry HTGR benchmark problems and a 2D hexagonal geometry PWR (WWER) benchmark problem have been solved by using the finite element diffusion code DIFGEN. The hexagons (or hexagonal prisms) were subdivided into first order or second order triangles or quadrilaterals (or triangular or quadrilateral prisms). In the 2D HTGR case of the number of the inserted absorber rods was also varied (7, 6, 0 or 37 rods). The calculational results are in a good agreement with the results of other calculations. The larger systematic series of DIFGEN calculations have given a quantitative picture on the convergence properties of various finite element modellings of hexagonal grids in DIFGEN. (orig.)
Koldan, Jelena; Puzyrev, Vladimir; de la Puente, Josep; Houzeaux, Guillaume; Cela, José María
2014-06-01
We present an elaborate preconditioning scheme for Krylov subspace methods which has been developed to improve the performance and reduce the execution time of parallel node-based finite-element (FE) solvers for 3-D electromagnetic (EM) numerical modelling in exploration geophysics. This new preconditioner is based on algebraic multigrid (AMG) that uses different basic relaxation methods, such as Jacobi, symmetric successive over-relaxation (SSOR) and Gauss-Seidel, as smoothers and the wave front algorithm to create groups, which are used for a coarse-level generation. We have implemented and tested this new preconditioner within our parallel nodal FE solver for 3-D forward problems in EM induction geophysics. We have performed series of experiments for several models with different conductivity structures and characteristics to test the performance of our AMG preconditioning technique when combined with biconjugate gradient stabilized method. The results have shown that, the more challenging the problem is in terms of conductivity contrasts, ratio between the sizes of grid elements and/or frequency, the more benefit is obtained by using this preconditioner. Compared to other preconditioning schemes, such as diagonal, SSOR and truncated approximate inverse, the AMG preconditioner greatly improves the convergence of the iterative solver for all tested models. Also, when it comes to cases in which other preconditioners succeed to converge to a desired precision, AMG is able to considerably reduce the total execution time of the forward-problem code-up to an order of magnitude. Furthermore, the tests have confirmed that our AMG scheme ensures grid-independent rate of convergence, as well as improvement in convergence regardless of how big local mesh refinements are. In addition, AMG is designed to be a black-box preconditioner, which makes it easy to use and combine with different iterative methods. Finally, it has proved to be very practical and efficient in the
Hervy, B.; Billen, R.; Laroche, F.; Carré, C.; Servières, M.; Van Ruymbeke, M.; Tourre, V.; Delfosse, V.; Kerouanton, J.-L.
2012-10-01
Museums are filled with hidden secrets. One of those secrets lies behind historical mock-ups whose signification goes far behind a simple representation of a city. We face the challenge of designing, storing and showing knowledge related to these mock-ups in order to explain their historical value. Over the last few years, several mock-up digitalisation projects have been realised. Two of them, Nantes 1900 and Virtual Leodium, propose innovative approaches that present a lot of similarities. This paper presents a framework to go one step further by analysing their data modelling processes and extracting what could be a generalized approach to build a numerical mock-up and the knowledge database associated. Geometry modelling and knowledge modelling influence each other and are conducted in a parallel process. Our generalized approach describes a global overview of what can be a data modelling process. Our next goal is obviously to apply this global approach on other historical mock-up, but we also think about applying it to other 3D objects that need to embed semantic data, and approaching historically enriched 3D city models.
The Stagger-grid: A grid of 3D stellar atmosphere models. I. Methods and general properties
Magic, Z.; Collet, R.; Asplund, M.; Trampedach, R.; Hayek, W.; Chiavassa, A.; Stein, R. F.; Nordlund, Å.
2013-09-01
Aims: We present the Stagger-grid, a comprehensive grid of time-dependent, three-dimensional (3D), hydrodynamic model atmospheres for late-type stars with realistic treatment of radiative transfer, covering a wide range in stellar parameters. This grid of 3D models is intended for various applications besides studies of stellar convection and atmospheres per se, including stellar parameter determination, stellar spectroscopy and abundance analysis, asteroseismology, calibration of stellar evolution models, interferometry, and extrasolar planet search. In this introductory paper, we describe the methods we applied for the computation of the grid and discuss the general properties of the 3D models as well as of their temporal and spatial averages (here denoted ⟨3D⟩ models). Methods: All our models were generated with the Stagger-code, using realistic input physics for the equation of state (EOS) and for continuous and line opacities. Our ~ 220 grid models range in effective temperature, Teff, from 4000 to 7000 K in steps of 500 K, in surface gravity, log g, from 1.5 to 5.0 in steps of 0.5 dex, and metallicity, [Fe/H], from - 4.0 to + 0.5 in steps of 0.5 and 1.0 dex. Results: We find a tight scaling relation between the vertical velocity and the surface entropy jump, which itself correlates with the constant entropy value of the adiabatic convection zone. The range in intensity contrast is enhanced at lower metallicity. The granule size correlates closely with the pressure scale height sampled at the depth of maximum velocity. We compare the ⟨3D⟩ models with currently widely applied one-dimensional (1D) atmosphere models, as well as with theoretical 1D hydrostatic models generated with the same EOS and opacity tables as the 3D models, in order to isolate the effects of using self-consistent and hydrodynamic modeling of convection, rather than the classical mixing length theory approach. For the first time, we are able to quantify systematically over a broad
Biyabani, S. R.
1994-01-01
INS3D computes steady-state solutions to the incompressible Navier-Stokes equations. The INS3D approach utilizes pseudo-compressibility combined with an approximate factorization scheme. This computational fluid dynamics (CFD) code has been verified on problems such as flow through a channel, flow over a backwardfacing step and flow over a circular cylinder. Three dimensional cases include flow over an ogive cylinder, flow through a rectangular duct, wind tunnel inlet flow, cylinder-wall juncture flow and flow through multiple posts mounted between two plates. INS3D uses a pseudo-compressibility approach in which a time derivative of pressure is added to the continuity equation, which together with the momentum equations form a set of four equations with pressure and velocity as the dependent variables. The equations' coordinates are transformed for general three dimensional applications. The equations are advanced in time by the implicit, non-iterative, approximately-factored, finite-difference scheme of Beam and Warming. The numerical stability of the scheme depends on the use of higher-order smoothing terms to damp out higher-frequency oscillations caused by second-order central differencing. The artificial compressibility introduces pressure (sound) waves of finite speed (whereas the speed of sound would be infinite in an incompressible fluid). As the solution converges, these pressure waves die out, causing the derivation of pressure with respect to time to approach zero. Thus, continuity is satisfied for the incompressible fluid in the steady state. Computational efficiency is achieved using a diagonal algorithm. A block tri-diagonal option is also available. When a steady-state solution is reached, the modified continuity equation will satisfy the divergence-free velocity field condition. INS3D is capable of handling several different types of boundaries encountered in numerical simulations, including solid-surface, inflow and outflow, and far
Yan, Yiming; Su, Nan; Zhao, Chunhui; Wang, Liguo
2017-09-19
In this paper, a novel framework of the 3D reconstruction of buildings is proposed, focusing on remote sensing super-generalized stereo-pairs (SGSPs). As we all know, 3D reconstruction cannot be well performed using nonstandard stereo pairs, since reliable stereo matching could not be achieved when the image-pairs are collected at a great difference of views, and we always failed to obtain dense 3D points for regions of buildings, and cannot do further 3D shape reconstruction. We defined SGSPs as two or more optical images collected in less constrained views but covering the same buildings. It is even more difficult to reconstruct the 3D shape of a building by SGSPs using traditional frameworks. As a result, a dynamic multi-projection-contour approximating (DMPCA) framework was introduced for SGSP-based 3D reconstruction. The key idea is that we do an optimization to find a group of parameters of a simulated 3D model and use a binary feature-image that minimizes the total differences between projection-contours of the building in the SGSPs and that in the simulated 3D model. Then, the simulated 3D model, defined by the group of parameters, could approximate the actual 3D shape of the building. Certain parameterized 3D basic-unit-models of typical buildings were designed, and a simulated projection system was established to obtain a simulated projection-contour in different views. Moreover, the artificial bee colony algorithm was employed to solve the optimization. With SGSPs collected by the satellite and our unmanned aerial vehicle, the DMPCA framework was verified by a group of experiments, which demonstrated the reliability and advantages of this work.
On generalized operator quasi-equilibrium problems
Kum, Sangho; Kim, Won Kyu
2008-09-01
In this paper, we will introduce the generalized operator equilibrium problem and generalized operator quasi-equilibrium problem which generalize the operator equilibrium problem due to Kazmi and Raouf [K.R. Kazmi, A. Raouf, A class of operator equilibrium problems, J. Math. Anal. Appl. 308 (2005) 554-564] into multi-valued and quasi-equilibrium problems. Using a Fan-Browder type fixed point theorem in [S. Park, Foundations of the KKM theory via coincidences of composites of upper semicontinuous maps, J. Korean Math. Soc. 31 (1994) 493-519] and an existence theorem of equilibrium for 1-person game in [X.-P. Ding, W.K. Kim, K.-K. Tan, Equilibria of non-compact generalized games with L*-majorized preferences, J. Math. Anal. Appl. 164 (1992) 508-517] as basic tools, we prove new existence theorems on generalized operator equilibrium problem and generalized operator quasi-equilibrium problem which includes operator equilibrium problems.
DIF3D: a code to solve one-, two-, and three-dimensional finite-difference diffusion theory problems
International Nuclear Information System (INIS)
Derstine, K.L.
1984-04-01
The mathematical development and numerical solution of the finite-difference equations are summarized. The report provides a guide for user application and details the programming structure of DIF3D. Guidelines are included for implementing the DIF3D export package on several large scale computers. Optimized iteration methods for the solution of large-scale fast-reactor finite-difference diffusion theory calculations are presented, along with their theoretical basis. The computational and data management considerations that went into their formulation are discussed. The methods utilized include a variant of the Chebyshev acceleration technique applied to the outer fission source iterations and an optimized block successive overrelaxation method for the within-group iterations. A nodal solution option intended for analysis of LMFBR designs in two- and three-dimensional hexagonal geometries is incorporated in the DIF3D package and is documented in a companion report, ANL-83-1
General Research and Development problems in dismantling
International Nuclear Information System (INIS)
Lorin, C.
1993-01-01
R and D studies for dismantling nuclear facilities have been conducted in several domains: safety evaluation (3D cameras, gamma camera, gamma low level control bench, alpha measures); general studies (such as the Baladin software, an expert system for dismantling); decontamination techniques (utilisation of acid or base liquids, laser, ...); cutting techniques and tools (remote controlled grinder, remote controlled robot, carrier crane); robotics for remote operations and handling; waste processing
3D adaptive finite element method for a phase field model for the moving contact line problems
Shi, Yi
2013-08-01
In this paper, we propose an adaptive finite element method for simulating the moving contact line problems in three dimensions. The model that we used is the coupled Cahn-Hilliard Navier-Stokes equations with the generalized Navier boundary condition(GNBC) proposed in [18]. In our algorithm, to improve the efficiency of the simulation, we use the residual type adaptive finite element algorithm. It is well known that the phase variable decays much faster away from the interface than the velocity variables. There- fore we use an adaptive strategy that will take into account of such difference. Numerical experiments show that our algorithm is both efficient and reliable. © 2013 American Institute of Mathematical Sciences.
Nadeem, Qurrat-Ul-Ain
2015-05-07
Previous studies have confirmed the adverse impact of fading correlation on the mutual information (MI) of two-dimensional (2D) multiple-input multiple-output (MIMO) systems. More recently, the trend is to enhance the system performance by exploiting the channel’s degrees of freedom in the elevation, which necessitates the derivation and characterization of three-dimensional (3D) channels in the presence of spatial correlation. In this paper, an exact closed-form expression for the Spatial Correlation Function (SCF) is derived for 3D MIMO channels. This novel SCF is developed for a uniform linear array of antennas with nonisotropic antenna patterns. The proposed method resorts to the spherical harmonic expansion (SHE) of plane waves and the trigonometric expansion of Legendre and associated Legendre polynomials. The resulting expression depends on the underlying arbitrary angular distributions and antenna patterns through the Fourier Series (FS) coefficients of power azimuth and elevation spectrums. The novelty of the proposed method lies in the SCF being valid for any 3D propagation environment. The developed SCF determines the covariance matrices at the transmitter and the receiver that form the Kronecker channel model. In order to quantify the effects of correlation on the system performance, the information-theoretic deterministic equivalents of the MI for the Kronecker model are utilized in both mono-user and multi-user cases. Numerical results validate the proposed analytical expressions and elucidate the dependence of the system performance on azimuth and elevation angular spreads and antenna patterns. Some useful insights into the behaviour of MI as a function of downtilt angles are provided. The derived model will help evaluate the performance of correlated 3D MIMO channels in the future.
Fakis, Demetrios; Kalvouridis, Tilemahos
2017-09-01
The regular polygon problem of (N+1) bodies deals with the dynamics of a small body, natural or artificial, in the force field of N big bodies, the ν=N-1 of which have equal masses and form an imaginary regular ν -gon, while the Nth body with a different mass is located at the center of mass of the system. In this work, instead of considering Newtonian potentials and forces, we assume that the big bodies create quasi-homogeneous potentials, in the sense that we insert to the inverse square Newtonian law of gravitation an inverse cube corrective term, aiming to approximate various phenomena due to their shape or to the radiation emitting from the primaries. Based on this new consideration, we apply a general methodology in order to investigate by means of the zero-velocity surfaces, the regions where 3D motions of the small body are allowed, their evolutions and parametric variations, their topological bifurcations, as well as the existing trapping domains of the particle. Here we note that this process is definitely a fundamental step of great importance in the study of many dynamical systems characterized by a Jacobian-type integral of motion in the long way of searching for solutions of any kind.
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...
Milton, Graeme W.; Camar-Eddine, Mohamed
2018-05-01
For a composite containing one isotropic elastic material, with positive Lame moduli, and void, with the elastic material occupying a prescribed volume fraction f, and with the composite being subject to an average stress, σ0 , Gibiansky, Cherkaev, and Allaire provided a sharp lower bound Wf(σ0) on the minimum compliance energy σ0 :ɛ0 , in which ɛ0 is the average strain. Here we show these bounds also provide sharp bounds on the possible (σ0 ,ɛ0) -pairs that can coexist in such composites, and thus solve the weak G-closure problem for 3d-printed materials. The materials we use to achieve the extremal (σ0 ,ɛ0) -pairs are denoted as near optimal pentamodes. We also consider two-phase composites containing this isotropic elasticity material and a rigid phase with the elastic material occupying a prescribed volume fraction f, and with the composite being subject to an average strain, ɛ0. For such composites, Allaire and Kohn provided a sharp lower bound W˜f(ɛ0) on the minimum elastic energy σ0 :ɛ0 . We show that these bounds also provide sharp bounds on the possible (σ0 ,ɛ0) -pairs that can coexist in such composites of the elastic and rigid phases, and thus solve the weak G-closure problem in this case too. The materials we use to achieve these extremal (σ0 ,ɛ0) -pairs are denoted as near optimal unimodes.
International Nuclear Information System (INIS)
Holt, L.; Rohde, U.; Seidl, M.; Schubert, A.; Van Uffelen, P.; Macián-Juan, R.
2015-01-01
Highlights: • A general coupling interface was developed for couplings of the TRANSURANUS code. • With this new tool simplified fuel behavior models in codes can be replaced. • Applicable e.g. for several reactor types and from normal operation up to DBA. • The general coupling interface was applied to the reactor dynamics code DYN3D. • The new coupled code system DYN3D–TRANSURANUS was successfully tested for RIA. - Abstract: A general interface is presented for coupling the TRANSURANUS fuel performance code with thermal hydraulics system, sub-channel thermal hydraulics, computational fluid dynamics (CFD) or reactor dynamics codes. As first application the reactor dynamics code DYN3D was coupled at assembly level in order to describe the fuel behavior in more detail. In the coupling, DYN3D provides process time, time-dependent rod power and thermal hydraulics conditions to TRANSURANUS, which in case of the two-way coupling approach transfers parameters like fuel temperature and cladding temperature back to DYN3D. Results of the coupled code system are presented for the reactivity transient scenario, initiated by control rod ejection. More precisely, the two-way coupling approach systematically calculates higher maximum values for the node fuel enthalpy. These differences can be explained thanks to the greater detail in fuel behavior modeling. The numerical performance for DYN3D–TRANSURANUS was proved to be fast and stable. The coupled code system can therefore improve the assessment of safety criteria, at a reasonable computational cost
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 have...
Dimensional reduction of a generalized flux problem
International Nuclear Information System (INIS)
Moroz, A.
1992-01-01
In this paper, a generalized flux problem with Abelian and non-Abelian fluxes is considered. In the Abelian case we shall show that the generalized flux problem for tight-binding models of noninteracting electrons on either 2n- or (2n + 1)-dimensional lattice can always be reduced to an n-dimensional hopping problem. A residual freedom in this reduction enables one to identify equivalence classes of hopping Hamiltonians which have the same spectrum. In the non-Abelian case, the reduction is not possible in general unless the flux tensor factorizes into an Abelian one times are element of the corresponding algebra
International Nuclear Information System (INIS)
Chu, M.S.; Ichiguchi, K.
2005-05-01
Formation of a method for the systematic computation of the growth rate of the weakly unstable RWM in 3D configurations by using results from ideal stability codes is presented. It is shown that the growth rate of the RWM is approximately given by the rate at which the available free energy for the ideal external kink mode can be dissipated by the resistive wall. The eigenfunction is also approximated by that of the external kink mode. This formulation is demonstrated by coupling to the ideal MHD code KSTEP with computation of the dissipation on the resistive wall. Results of the stability of the RWM in LHD plasmas and discussion on the validity and improvement to the computation are also included. (author)
Energy Technology Data Exchange (ETDEWEB)
Iliesiu, Luca [Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (United States); Kos, Filip; Poland, David [Department of Physics, Yale University, New Haven, CT 06520 (United States); Pufu, Silviu S. [Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (United States); Simmons-Duffin, David [School of Natural Sciences, Institute for Advanced Study, Princeton, NJ 08540 (United States); Yacoby, Ran [Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (United States)
2016-03-17
We study the conformal bootstrap for a 4-point function of fermions 〈ψψψψ〉 in 3D. We first introduce an embedding formalism for 3D spinors and compute the conformal blocks appearing in fermion 4-point functions. Using these results, we find general bounds on the dimensions of operators appearing in the ψ×ψ OPE, and also on the central charge C{sub T}. We observe features in our bounds that coincide with scaling dimensions in the Gross-Neveu models at large N. We also speculate that other features could coincide with a fermionic CFT containing no relevant scalar operators.
Algorithm for the Stochastic Generalized Transportation Problem
Directory of Open Access Journals (Sweden)
Marcin Anholcer
2012-01-01
Full Text Available The equalization method for the stochastic generalized transportation problem has been presented. The algorithm allows us to find the optimal solution to the problem of minimizing the expected total cost in the generalized transportation problem with random demand. After a short introduction and literature review, the algorithm is presented. It is a version of the method proposed by the author for the nonlinear generalized transportation problem. It is shown that this version of the method generates a sequence of solutions convergent to the KKT point. This guarantees the global optimality of the obtained solution, as the expected cost functions are convex and twice differentiable. The computational experiments performed for test problems of reasonable size show that the method is fast. (original abstract
A generalization of the convex Kakeya problem
Ahn, Heekap; Bae, Sangwon; Cheong, Otfried; Gudmundsson, Joachim; Tokuyama, Takeshi; Vigneron, Antoine E.
2012-01-01
We consider the following geometric alignment problem: Given a set of line segments in the plane, find a convex region of smallest area that contains a translate of each input segment. This can be seen as a generalization of Kakeya's problem
International Nuclear Information System (INIS)
Holt, L.; Rohde, U.; Seidl, M.; Schubert, A.; Van Uffelen, P.
2013-01-01
Several institutions plan to couple the fuel performance code TRANSURANUS developed by the European Institute for Transuranium Elements with their own codes. One of these codes is the reactor dynamic code DYN3D maintained by the Helmholtz-Zentrum Dresden - Rossendorf. DYN3D was developed originally for VVER type reactors and was extended later to western type reactors. Usually, the fuel rod behavior is modeled in thermal hydraulics and neutronic codes in a simplified manner. The main idea of this coupling is to describe the fuel rod behavior in the frame of core safety analysis in a more detailed way, e.g. including the influence of the high burn-up structure, geometry changes and fission gas release. It allows to take benefit from the improved computational power and software achieved over the last two decades. The coupling interface was developed in a general way from the beginning. Thence it can be easily used also by other codes for a coupling with TRANSURANUS. The user can choose between a one-way as well as a two-way online coupling option. For a one-way online coupling, DYN3D provides only the time-dependent rod power and thermal hydraulics conditions to TRANSURANUS, but the fuel performance code doesn’t transfer any variable back to DYN3D. In a two-way online coupling, TRANSURANUS in addition transfers parameters like fuel temperature and cladding temperature back to DYN3D. This list of variables can be extended easily by geometric and further variables of interest. First results of the code system DYN3D-TRANSURANUS will be presented for a control rod ejection transient in a modern western type reactor. Pre-analyses show already that a detailed fuel rod behavior modeling will influence the thermal hydraulics and thence also the neutronics due to the Doppler reactivity effect of the fuel temperature. The coupled code system has therefore a potential to improve the assessment of safety criteria. The developed code system DYN3D-TRANSURANUS can be used also
International Nuclear Information System (INIS)
Crosetto, D.
1992-12-01
Experience demonstrates that fine tuning on the trigger of an experiment is often achieved only after running the experiment and analyzing the first data acquired. It is desirable that identification and, consequently, selection of interesting events be made on a more refined identification of particles. Use of an innovative parallel-processing system architecture together with an instruction set allows identification of objects (particles) among the data coming from a calorimeter in a programmable manner, utilizing the information related to their shape in two- or three-dimensional form, rather than applying only a programmable threshold proportional to their energy. The architecture is flexible, allowing execution of simple algorithms as well as complex pattern recognition algorithms. It is scalable in the sense that the same hardware can be used for small or large calorimeters having a slow or fast event rate. The simple printed circuit board (accommodating 16 x 3D-Flow processors) on a 4 in. x 4 in. board described herein uses the same hardware to build a large Level-1 programmable trigger (by interconnecting many boards in a matrix array) and is capable of implementing simple or complex pattern recognition algorithms at different event input rates (by cascading boards one on top of another). With the same hardware one can build low-cost, programmable Level-1 triggers for a small and low-event-rate calorimeter, or high-performance, programmable Level-1 triggers for a large calorimeter capable of sustaining up to 60 million events per second
Directory of Open Access Journals (Sweden)
Hüseyin Eldem
2017-08-01
Full Text Available Traveling Salesman Problem (TSP is a problem in combinatorial optimization that should be solved by a salesperson who has to travel all cities at the minimum cost (minimum route and return to the starting city (node. Todays, to resolve the minimum cost of this problem, many optimization algorithms have been used. The major ones are these metaheuristic algorithms. In this study, one of the metaheuristic methods, Ant Colony Optimization (ACO method (Max-Min Ant System – MMAS, was used to solve the Non-Euclidean TSP, which consisted of sets of different count points coincidentally located on the surface of a sphere. In this study seven point sets were used which have different point count. The performance of the MMAS method solving Non-Euclidean TSP problem was demonstrated by different experiments. Also, the results produced by ACO are compared with Discrete Cuckoo Search Algorithm (DCS and Genetic Algorithm (GA that are in the literature. The experiments for TSP on a sphere, show that ACO’s average results were better than the GA’s average results and also best results of ACO successful than the DCS.
Transfer of Problem Solving Skills from Touchscreen to 3D Model by 3- to 6-Year-Olds.
Tarasuik, Joanne; Demaria, Ana; Kaufman, Jordy
2017-01-01
Although much published research purports that young children struggle to solve problems from screen-based media and to transfer learning from a virtual to a physical modality, Huber et al. (2016)'s recent study on children solving the Tower of Hanoi (ToH) problem on a touchscreen app offers a clear counter example. Huber et al. (2016) reported that children transferred learning from media to the physical world. As this finding arguably differs from that of prior research in this area, the current study tests whether the Huber et al. (2016) results could be replicated. Additionally, we extended the scope of the Huber et al. (2016) work by testing a broader age range, including children as young as 3 years, and using a culturally distinct participant pool. The results of the current study verified Huber et al.'s (2016) conclusion that 4- to 6-year-old children are capable of transferring the ToH learning from touchscreen devices to the physical version of the puzzle. Children under 4 years of age, in contrast, showed little ability to improve at the ToH problem regardless of the practice modality-suggesting that a different problem-solving task is required to probe very young children's ability to learn from touchscreen apps.
International Nuclear Information System (INIS)
Barnes, D.C.; Brackbill, J.U.
1977-01-01
A numerical study of the equilibrium and stability properties of the Scyllac experiment at Los Alamos is described. The formulation of the numerical method, which is an extension of the ICED-ALE method to magnetohydrodynamic flow in three dimensions, is given. The properties of the method are discussed, including low computational diffusion, local conservation, and implicit formulation in the time variable. Also discussed are the problems encountered in applying boundary conditions and computing equilibria. The results of numerical computations of equilibria indicate that the helical field amplitudes must be doubled from their design values to produce equilibrium in the Scyllac experiment. This is consistent with other theoretical and experimental results
Beckstein, Pascal; Galindo, Vladimir; Vukčević, Vuko
2017-09-01
Eddy-current problems occur in a wide range of industrial and metallurgical applications where conducting material is processed inductively. Motivated by realising coupled multi-physics simulations, we present a new method for the solution of such problems in the finite volume framework of foam-extend, an extended version of the very popular OpenFOAM software. The numerical procedure involves a semi-coupled multi-mesh approach to solve Maxwell's equations for non-magnetic materials by means of the Coulomb gauged magnetic vector potential A and the electric scalar potential ϕ. The concept is further extended on the basis of the impressed and reduced magnetic vector potential and its usage in accordance with Biot-Savart's law to achieve a very efficient overall modelling even for complex three-dimensional geometries. Moreover, we present a special discretisation scheme to account for possible discontinuities in the electrical conductivity. To complement our numerical method, an extensive validation is completing the paper, which provides insight into the behaviour and the potential of our approach.
Generalized network improvement and packing problems
Holzhauser, Michael
2016-01-01
Michael Holzhauser discusses generalizations of well-known network flow and packing problems by additional or modified side constraints. By exploiting the inherent connection between the two problem classes, the author investigates the complexity and approximability of several novel network flow and packing problems and presents combinatorial solution and approximation algorithms. Contents Fractional Packing and Parametric Search Frameworks Budget-Constrained Minimum Cost Flows: The Continuous Case Budget-Constrained Minimum Cost Flows: The Discrete Case Generalized Processing Networks Convex Generalized Flows Target Groups Researchers and students in the fields of mathematics, computer science, and economics Practitioners in operations research and logistics The Author Dr. Michael Holzhauser studied computer science at the University of Kaiserslautern and is now a research fellow in the Optimization Research Group at the Department of Mathematics of the University of Kaiserslautern.
Costiner, Sorin; Taasan, Shlomo
1994-01-01
This paper presents multigrid (MG) techniques for nonlinear eigenvalue problems (EP) and emphasizes an MG algorithm for a nonlinear Schrodinger EP. The algorithm overcomes the mentioned difficulties combining the following techniques: an MG projection coupled with backrotations for separation of solutions and treatment of difficulties related to clusters of close and equal eigenvalues; MG subspace continuation techniques for treatment of the nonlinearity; an MG simultaneous treatment of the eigenvectors at the same time with the nonlinearity and with the global constraints. The simultaneous MG techniques reduce the large number of self consistent iterations to only a few or one MG simultaneous iteration and keep the solutions in a right neighborhood where the algorithm converges fast.
Prevalence of alcohol problems in general practice
DEFF Research Database (Denmark)
Rambaldi, A; Todisco, N; Gluud, C
1996-01-01
The Michigan Alcoholism Screening Test (MAST) and the response to a question about heavy alcohol consumption were used to assess the prevalence of alcohol problems in consecutive patients (77 males and 46 females) consulting a general practitioner in an urban area in the South of Italy (Castellam...... as a screening question in order to detect alcohol problems and give advice regarding reduction of alcohol consumption....
3D IBFV : Hardware-Accelerated 3D Flow Visualization
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
Generalized production planning problem under interval uncertainty
Directory of Open Access Journals (Sweden)
Samir A. Abass
2010-06-01
Full Text Available Data in many real life engineering and economical problems suffer from inexactness. Herein we assume that we are given some intervals in which the data can simultaneously and independently perturb. We consider the generalized production planning problem with interval data. The interval data are in both of the objective function and constraints. The existing results concerning the qualitative and quantitative analysis of basic notions in parametric production planning problem. These notions are the set of feasible parameters, the solvability set and the stability set of the first kind.
A general heuristic for genome rearrangement problems.
Dias, Ulisses; Galvão, Gustavo Rodrigues; Lintzmayer, Carla Négri; Dias, Zanoni
2014-06-01
In this paper, we present a general heuristic for several problems in the genome rearrangement field. Our heuristic does not solve any problem directly, it is rather used to improve the solutions provided by any non-optimal algorithm that solve them. Therefore, we have implemented several algorithms described in the literature and several algorithms developed by ourselves. As a whole, we implemented 23 algorithms for 9 well known problems in the genome rearrangement field. A total of 13 algorithms were implemented for problems that use the notions of prefix and suffix operations. In addition, we worked on 5 algorithms for the classic problem of sorting by transposition and we conclude the experiments by presenting results for 3 approximation algorithms for the sorting by reversals and transpositions problem and 2 approximation algorithms for the sorting by reversals problem. Another algorithm with better approximation ratio can be found for the last genome rearrangement problem, but it is purely theoretical with no practical implementation. The algorithms we implemented in addition to our heuristic lead to the best practical results in each case. In particular, we were able to improve results on the sorting by transpositions problem, which is a very special case because many efforts have been made to generate algorithms with good results in practice and some of these algorithms provide results that equal the optimum solutions in many cases. Our source codes and benchmarks are freely available upon request from the authors so that it will be easier to compare new approaches against our results.
Omelyan, Igor; Kovalenko, Andriy
2015-04-14
We developed a generalized solvation force extrapolation (GSFE) approach to speed up multiple time step molecular dynamics (MTS-MD) of biomolecules steered with mean solvation forces obtained from the 3D-RISM-KH molecular theory of solvation (three-dimensional reference interaction site model with the Kovalenko-Hirata closure). GSFE is based on a set of techniques including the non-Eckart-like transformation of coordinate space separately for each solute atom, extension of the force-coordinate pair basis set followed by selection of the best subset, balancing the normal equations by modified least-squares minimization of deviations, and incremental increase of outer time step in motion integration. Mean solvation forces acting on the biomolecule atoms in conformations at successive inner time steps are extrapolated using a relatively small number of best (closest) solute atomic coordinates and corresponding mean solvation forces obtained at previous outer time steps by converging the 3D-RISM-KH integral equations. The MTS-MD evolution steered with GSFE of 3D-RISM-KH mean solvation forces is efficiently stabilized with our optimized isokinetic Nosé-Hoover chain (OIN) thermostat. We validated the hybrid MTS-MD/OIN/GSFE/3D-RISM-KH integrator on solvated organic and biomolecules of different stiffness and complexity: asphaltene dimer in toluene solvent, hydrated alanine dipeptide, miniprotein 1L2Y, and protein G. The GSFE accuracy and the OIN efficiency allowed us to enlarge outer time steps up to huge values of 1-4 ps while accurately reproducing conformational properties. Quasidynamics steered with 3D-RISM-KH mean solvation forces achieves time scale compression of conformational changes coupled with solvent exchange, resulting in further significant acceleration of protein conformational sampling with respect to real time dynamics. Overall, this provided a 50- to 1000-fold effective speedup of conformational sampling for these systems, compared to conventional MD
Generalized Riemann problem for reactive flows
International Nuclear Information System (INIS)
Ben-Artzi, M.
1989-01-01
A generalized Riemann problem is introduced for the equations of reactive non-viscous compressible flow in one space dimension. Initial data are assumed to be linearly distributed on both sides of a jump discontinuity. The resolution of the singularity is studied and the first-order variation (in time) of flow variables is given in exact form. copyright 1989 Academic Press, Inc
van Haver, Sven; Janssen, Olaf T. A.; Braat, Joseph J. M.; Janssen, Augustus J. E. M.; Urbach, H. Paul; Pereira, Silvania F.
2008-03-01
In this paper we introduce a new mask imaging algorithm that is based on the source point integration method (or Abbe method). The method presented here distinguishes itself from existing methods by exploiting the through-focus imaging feature of the Extended Nijboer-Zernike (ENZ) theory of diffraction. An introduction to ENZ-theory and its application in general imaging is provided after which we describe the mask imaging scheme that can be derived from it. The remainder of the paper is devoted to illustrating the advantages of the new method over existing methods (Hopkins-based). To this extent several simulation results are included that illustrate advantages arising from: the accurate incorporation of isolated structures, the rigorous treatment of the object (mask topography) and the fully vectorial through-focus image formation of the ENZ-based algorithm.
International Nuclear Information System (INIS)
Chin, Yong Ho; Kim, Kwang-Je; Xie, Ming.
1992-08-01
In the previous paper, we have derived a dispersion relation for the free electron laser (FEL) gain in the exponential regime taking account the diffraction and electron's betatron oscillation. Here, we compare the growth rates obtained by solving the dispersion relation with those obtained by simulation calculation for the waterbag and the Gaussian models for the electron's transverse phase space distribution. The agreement is found to be good except for the limiting case where the Rayleigh length is much longer than the gain length (1-D limit). We also generalize the analysis to the case where the electron beam cross section is elliptical as is usually the case in storage rings, and derive the first-order dispersion relation
Rodriguez, Rudy U; Kemper, Nathan; Breathwaite, Erick; Dutta, Sucharita M; Hsu, Erin L; Hsu, Wellington K; Francis, Michael P
2016-07-26
Bone repair frequently requires time-consuming implant construction, particularly when using un-formed implants with poor handling properties. We therefore developed osteoinductive, micro-fibrous surface patterned demineralized bone matrix (DBM) fibers for engineering both defect-matched and general three-dimensional implants. Implant molds were filled with demineralized human cortical bone fibers there were compressed and lyophilized, forming mechanically strong shaped DBM scaffolds. Enzyme linked immunosorbent assays and mass spectrometry confirmed that DBM fibers contained abundant osteogenic growth factors (bone morphogenetic proteins, insulin-like growth factor-I) and extracellular matrix proteins. Mercury porosimetry and mechanical testing showed interconnected pores within the mechanically stable, custom DBM fiber scaffolds. Mesenchymal stem cells readily attached to the DBM and showed increasing metabolic activity over time. DBM fibers further increased alkaline phosphatase activity in C2C12 cells. In vivo, DBM implants elicited osteoinductive potential in a mouse muscle pouch, and also promoted spine fusion in a rat arthrodesis model. DBM fibers can be engineered into custom-shaped, osteoinductive and osteoconductive implants with potential for repairing osseous defects with precise fitment, potentially reducing operating time. By providing pre-formed and custom implants, this regenerative allograft may improve patient outcomes following surgical bone repair, while further advancing personalized orthopedic and craniomaxillofacial medicine using three-dimensional-printed tissue molds.
Generalized Benders’ Decomposition for topology optimization problems
DEFF Research Database (Denmark)
Munoz Queupumil, Eduardo Javier; Stolpe, Mathias
2011-01-01
) problems with discrete design variables to global optimality. We present the theoretical aspects of the method, including a proof of finite convergence and conditions for obtaining global optimal solutions. The method is also linked to, and compared with, an Outer-Approximation approach and a mixed 0......–1 semi definite programming formulation of the considered problem. Several ways to accelerate the method are suggested and an implementation is described. Finally, a set of truss topology optimization problems are numerically solved to global optimality.......This article considers the non-linear mixed 0–1 optimization problems that appear in topology optimization of load carrying structures. The main objective is to present a Generalized Benders’ Decomposition (GBD) method for solving single and multiple load minimum compliance (maximum stiffness...
3D composite image, 3D MRI, 3D SPECT, hydrocephalus
International Nuclear Information System (INIS)
Mito, T.; Shibata, I.; Sugo, N.; Takano, M.; Takahashi, H.
2002-01-01
The three-dimensional (3D)SPECT imaging technique we have studied and published for the past several years is an analytical tool that permits visual expression of the cerebral circulation profile in various cerebral diseases. The greatest drawback of SPECT is that the limitation on precision of spacial resolution makes intracranial localization impossible. In 3D SPECT imaging, intracranial volume and morphology may vary with the threshold established. To solve this problem, we have produced complimentarily combined SPECT and helical-CT 3D images by means of general-purpose visualization software for intracranial localization. In hydrocephalus, however, the key subject to be studied is the profile of cerebral circulation around the ventricles of the brain. This suggests that, for displaying the cerebral ventricles in three dimensions, CT is a difficult technique whereas MRI is more useful. For this reason, we attempted to establish the profile of cerebral circulation around the cerebral ventricles by the production of combined 3D images of SPECT and MRI. In patients who had shunt surgery for hydrocephalus, a difference between pre- and postoperative cerebral circulation profiles was assessed by a voxel distribution curve, 3D SPECT images, and combined 3D SPECT and MRI images. As the shunt system in this study, an Orbis-Sigma valve of the automatic cerebrospinal fluid volume adjustment type was used in place of the variable pressure type Medos valve currently in use, because this device requires frequent changes in pressure and a change in pressure may be detected after MRI procedure. The SPECT apparatus used was PRISM3000 of the three-detector type, and 123I-IMP was used as the radionuclide in a dose of 222 MBq. MRI data were collected with an MAGNEXa+2 with a magnetic flux density of 0.5 tesla under the following conditions: field echo; TR 50 msec; TE, 10 msec; flip, 30ueK; 1 NEX; FOV, 23 cm; 1-mm slices; and gapless. 3D images are produced on the workstation TITAN
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
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
Directory of Open Access Journals (Sweden)
Hai Ming Wong
2017-06-01
Full Text Available Faculty of Dentistry of the University of Hong Kong has introduced innovative blended problem-based learning (PBL with the aid of 3D electronic models (e-models to Bachelor of Dental Surgery (BDS curriculum. Statistical results of pre- and post-semester questionnaire surveys illustrated compatibility of e-models in PBL settings. The students’ importance ratings of two objectives “Complete assigned tasks on time” and “Active listener”, and twenty-two facilitator evaluation items including critical thinking and group problem-solving skills had increased significantly. The students’ PBL preparation behavior, attentions to problem understanding, problem analysis, and learning resource quality were also found to be related to online support of e-models and its software. Qualitative analysis of open-ended questions with visual text analytic software “Leximancer” improved validity of statistical results. Using e-model functions in treatment planning, problem analysis and giving instructions provided a method of informative communication. Therefore, it is critical for the faculty to continuously provide facilitator training and quality online e-model resources to the students.
Lobb's Generalization of Catalan's Parenthesization Problem
Koshy, Thomas
2009-01-01
A. Lobb discovered an interesting generalization of Catalan's parenthesization problem, namely: Find the number L(n, m) of arrangements of n + m positive ones and n - m negative ones such that every partial sum is nonnegative, where 0 = m = n. This article uses Lobb's formula, L(n, m) = (2m + 1)/(n + m + 1) C(2n, n + m), where C is the usual…
Generalized Darcy–Oseen resolvent problem
Czech Academy of Sciences Publication Activity Database
Medková, Dagmar; Ptashnyk, M.; Varnhorn, W.
2016-01-01
Roč. 39, č. 6 (2016), s. 1621-1630 ISSN 0170-4214 Institutional support: RVO:67985840 Keywords : Darcy-Oseen resolvent problem * semipermeable membrane * Brinkman-Darcy equations * fluid flow between free-fluid domains and porous media Subject RIV: BA - General Mathematics Impact factor: 1.017, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/mma.3872/abstract
A generalization of the convex Kakeya problem
Ahn, Heekap
2012-01-01
We consider the following geometric alignment problem: Given a set of line segments in the plane, find a convex region of smallest area that contains a translate of each input segment. This can be seen as a generalization of Kakeya\\'s problem of finding a convex region of smallest area such that a needle can be turned through 360 degrees within this region. Our main result is an optimal Θ(n log n)-time algorithm for our geometric alignment problem, when the input is a set of n line segments. We also show that, if the goal is to minimize the perimeter of the region instead of its area, then the optimum placement is when the midpoints of the segments coincide. Finally, we show that for any compact convex figure G, the smallest enclosing disk of G is a smallest-perimeter region containing a translate of any rotated copy of G. © 2012 Springer-Verlag Berlin Heidelberg.
PROBLEMS OF GENERAL PRACTICE IN RURAL CALIFORNIA
Carey, Hollis L.; Andrews, Carroll B.
1949-01-01
Medical care for rural populations is an important problem facing the medical profession nationally and locally. The mechanism for solution lies in the existing American Medical Association and California Medical Association committees on rural medical service and further development of “local health councils.” Additional emphasis on training of physicians for general practice is essential through medical school graduate and postgraduate periods. The problem of providing additional adequately equipped and staffed hospitals must receive much consideration. Recognizing that passiveness invites aggressive non-medical agencies to foster bureaucratic dictation inimical to the practice of medicine, the rural physician must act through medical and community organizations to correct weaknesses in the structure of medical practice. PMID:18116230
Gambling Problems in the General Danish Population
DEFF Research Database (Denmark)
Harrison, Glenn W.; Jessen, Lasse J.; Lau, Morten
We compare several popular survey instruments for measuring gambling behavior and gambling propensity to assess if they differ in their classification of individuals in the general adult Danish population. We also examine correlations with standard survey instruments for alcohol use, anxiety......, depression and impulsivity. A feature of our design is that nobody was excluded on the basis of their response to a “trigger,” “gateway” or “diagnostic item” question about previous gambling history. Our sample consists of 8,405 adult Danes. We administered the Focal Adult Gambling Screen to all subjects...... and estimate prevalence of gambling problems using sample weights and controlling for sample selection. We find that 95.4% of the population has no detectable risk, 2.9% has an early risk, 0.8% has an intermediate risk, 0.7% has an advanced risk, and 0.2% can be classified as problem gamblers...
Averaged description of 3D MHD equilibrium
International Nuclear Information System (INIS)
Medvedev, S.Yu.; Drozdov, V.V.; Ivanov, A.A.; Martynov, A.A.; Pashekhonov, Yu.Yu.; Mikhailov, M.I.
2001-01-01
A general approach by S.A.Galkin et al. in 1991 to 2D description of MHD equilibrium and stability in 3D systems was proposed. The method requires a background 3D equilibrium with nested flux surfaces to generate the metric of a Riemannian space in which the background equilibrium is described by the 2D equation of Grad-Shafranov type. The equation can be solved then varying plasma profiles and shape to get approximate 3D equilibria. In the framework of the method both planar axis conventional stellarators and configurations with spatial magnetic axis can be studied. In the present report the formulation and numerical realization of the equilibrium problem for stellarators with planar axis is reviewed. The input background equilibria with nested flux surfaces are taken from vacuum magnetic field approximately described by analytic scalar potential
Ruiz-Blanco, Yasser B; Paz, Waldo; Green, James; Marrero-Ponce, Yovani
2015-05-16
The exponential growth of protein structural and sequence databases is enabling multifaceted approaches to understanding the long sought sequence-structure-function relationship. Advances in computation now make it possible to apply well-established data mining and pattern recognition techniques to these data to learn models that effectively relate structure and function. However, extracting meaningful numerical descriptors of protein sequence and structure is a key issue that requires an efficient and widely available solution. We here introduce ProtDCal, a new computational software suite capable of generating tens of thousands of features considering both sequence-based and 3D-structural descriptors. We demonstrate, by means of principle component analysis and Shannon entropy tests, how ProtDCal's sequence-based descriptors provide new and more relevant information not encoded by currently available servers for sequence-based protein feature generation. The wide diversity of the 3D-structure-based features generated by ProtDCal is shown to provide additional complementary information and effectively completes its general protein encoding capability. As demonstration of the utility of ProtDCal's features, prediction models of N-linked glycosylation sites are trained and evaluated. Classification performance compares favourably with that of contemporary predictors of N-linked glycosylation sites, in spite of not using domain-specific features as input information. ProtDCal provides a friendly and cross-platform graphical user interface, developed in the Java programming language and is freely available at: http://bioinf.sce.carleton.ca/ProtDCal/ . ProtDCal introduces local and group-based encoding which enhances the diversity of the information captured by the computed features. Furthermore, we have shown that adding structure-based descriptors contributes non-redundant additional information to the features-based characterization of polypeptide systems. This
3-D neutron transport benchmarks
International Nuclear Information System (INIS)
Takeda, T.; Ikeda, H.
1991-03-01
A set of 3-D neutron transport benchmark problems proposed by the Osaka University to NEACRP in 1988 has been calculated by many participants and the corresponding results are summarized in this report. The results of K eff , control rod worth and region-averaged fluxes for the four proposed core models, calculated by using various 3-D transport codes are compared and discussed. The calculational methods used were: Monte Carlo, Discrete Ordinates (Sn), Spherical Harmonics (Pn), Nodal Transport and others. The solutions of the four core models are quite useful as benchmarks for checking the validity of 3-D neutron transport codes
Anholonomic Cauchy problem in general relativity
International Nuclear Information System (INIS)
Stachel, J.
1980-01-01
The Lie derivative approach to the Cauchy problem in general relativity is applied to the evolution along an arbitrary timelike vector field for the case where the dynamical degrees of freedom are chosen as the (generally anholonomic) metric of the hypersurface elements orthogonal to the vector field. Generalizations of the shear, rotation, and acceleration are given for a nonunit timelike vector field, and applied to the three-plus-one breakup of the Riemann tensor into components parallel and orthogonal to the vector field, resulting in the anholonomic Gauss--Codazzi equations. A similar breakup of the Einstein field equations results in the form of the constraint and evolution equations for the anholonomic case. The results are applied to the case of a space--time with a timelike Killing vector field (stationary field) to demonstrate their utility. Other possible applications, such as in the numerical integration of the field equations, are mentioned. Definitions are given of three-index shear, rotation, and acceleration tensors, and their use in a two-plus-two decomposition of the Riemann tensor and field equations is indicated
Directory of Open Access Journals (Sweden)
Felician ALECU
2010-01-01
Full Text Available Many professionals and 3D artists consider Blender as being the best open source solution for 3D computer graphics. The main features are related to modeling, rendering, shading, imaging, compositing, animation, physics and particles and realtime 3D/game creation.
Castineira, D.; Jha, B.; Juanes, R.
2016-12-01
Carbon Capture and Sequestration (CCS) is regarded as a promising technology to mitigate rising CO2 concentrations in the atmosphere from industrial emissions. However, as a result of the inherent uncertainty that is present in geological structures, assessing the stability of geological faults and quantifying the potential for induced seismicity is a fundamental challenge for practical implementation of CCS. Here we present a formal framework for the solution of the inverse problem associated with coupled flow and geomechanics models of CO2 injection and subsurface storage. Our approach builds from the application of Gaussian Processes, MCMC and posterior predictive analysis to evaluate relevant earthquake attributes (earthquake time, location and magnitude) in 3D synthetic models of CO2 storage under geologic, observational and operational uncertainty. In our approach, we first conduct hundreds of simulations of a high-fidelity 3D computational model for CO2 injection into a deep saline aquifer, dominated by an anticline structure and a fault. This ensemble of realizations accounts for uncertainty in the model parameters (including fault geomechanical and rock properties) and observations (earthquake time, location and magnitude). We apply Gaussian processes (GP) to generate a valid surrogate that closely approximates the behavior of the high fidelity (and computationally intensive) model, and apply hyperparameter optimization and cross-validation techniques in the solution of this multidimensional data-fit problem. The net result of this process is the generation of a fast model that can be effectively used for Bayesian analysis. We then implement Markov chain Monte Carlo (MCMC) to determine the posterior distribution of the model uncertain parameters (given some prior distributions for those parameters and given the likelihood defined in this case by the GP model). Our results show that the resulting posterior distributions correctly converge towards the "true
PLOT3D Export Tool for Tecplot
Alter, Stephen
2010-01-01
The PLOT3D export tool for Tecplot solves the problem of modified data being impossible to output for use by another computational science solver. The PLOT3D Exporter add-on enables the use of the most commonly available visualization tools to engineers for output of a standard format. The exportation of PLOT3D data from Tecplot has far reaching effects because it allows for grid and solution manipulation within a graphical user interface (GUI) that is easily customized with macro language-based and user-developed GUIs. The add-on also enables the use of Tecplot as an interpolation tool for solution conversion between different grids of different types. This one add-on enhances the functionality of Tecplot so significantly, it offers the ability to incorporate Tecplot into a general suite of tools for computational science applications as a 3D graphics engine for visualization of all data. Within the PLOT3D Export Add-on are several functions that enhance the operations and effectiveness of the add-on. Unlike Tecplot output functions, the PLOT3D Export Add-on enables the use of the zone selection dialog in Tecplot to choose which zones are to be written by offering three distinct options - output of active, inactive, or all zones (grid blocks). As the user modifies the zones to output with the zone selection dialog, the zones to be written are similarly updated. This enables the use of Tecplot to create multiple configurations of a geometry being analyzed. For example, if an aircraft is loaded with multiple deflections of flaps, by activating and deactivating different zones for a specific flap setting, new specific configurations of that aircraft can be easily generated by only writing out specific zones. Thus, if ten flap settings are loaded into Tecplot, the PLOT3D Export software can output ten different configurations, one for each flap setting.
Directory of Open Access Journals (Sweden)
SAVYTSKYI M. V.
2016-03-01
Full Text Available Raising of problem. Today, in all spheres of our life we can constate the permanent search for new, modern methods and technologies that meet the principles of sustainable development. New approaches need to be, on the one hand more effective in terms of conservation of exhaustible resources of our planet, have minimal impact on the environment and on the other hand to ensure a higher quality of the final product. Construction is not exception. One of the new promising technology is the technology of 3D -printing of individual structures and buildings in general. 3Dprinting - is the process of real object recreating on the model of 3D. Unlike conventional printer which prints information on a sheet of paper, 3D-printer allows you to display three-dimensional information, i.e. creates certain physical objects. Currently, 3D-printer finds its application in many areas of production: machine building elements, a variety of layouts, interior elements, various items. But due to the fact that this technology is fairly new, it requires the creation of detailed and accurate technologies, efficient equipment and materials, and development of common vocabulary and regulatory framework in this field. Research Aim. The analysis of existing methods of creating physical objects using 3D-printing and the improvement of technology and equipment for the printing of buildings and structures. Conclusion. 3D-printers building is a new generation of equipment for the construction of buildings, structures, and structural elements. A variety of building printing technics opens up wide range of opportunities in the construction industry. At this stage, printers design allows to create low-rise buildings of different configurations with different mortars. The scientific novelty of this work is to develop proposals to improve the thermal insulation properties of constructed 3D-printing objects and technological equipment. The list of key terms and notions of construction
Luciani, S.; LeNiliot, C.
2008-11-01
Two-phase and boiling flow instabilities are complex, due to phase change and the existence of several interfaces. To fully understand the high heat transfer potential of boiling flows in microscale's geometry, it is vital to quantify these transfers. To perform this task, an experimental device has been designed to observe flow patterns. Analysis is made up by using an inverse method which allows us to estimate the local heat transfers while boiling occurs inside a microchannel. In our configuration, the direct measurement would impair the accuracy of the searched heat transfer coefficient because thermocouples implanted on the surface minichannels would disturb the established flow. In this communication, we are solving a 3D IHCP which consists in estimating using experimental data measurements the surface temperature and the surface heat flux in a minichannel during convective boiling under several gravity levels (g, 1g, 1.8g). The considered IHCP is formulated as a mathematical optimization problem and solved using the boundary element method (BEM).
International Nuclear Information System (INIS)
Fevotte, F.; Lathuiliere, B.
2013-01-01
The large increase in computing power over the past few years now makes it possible to consider developing 3D full-core heterogeneous deterministic neutron transport solvers for reference calculations. Among all approaches presented in the literature, the method first introduced in [1] seems very promising. It consists in iterating over resolutions of 2D and ID MOC problems by taking advantage of prismatic geometries without introducing approximations of a low order operator such as diffusion. However, before developing a solver with all industrial options at EDF, several points needed to be clarified. In this work, we first prove the convergence of this iterative process, under some assumptions. We then present our high-performance, parallel implementation of this algorithm in the MICADO solver. Benchmarking the solver against the Takeda case shows that the 2D-1D coupling algorithm does not seem to affect the spatial convergence order of the MOC solver. As for performance issues, our study shows that even though the data distribution is suited to the 2D solver part, the efficiency of the ID part is sufficient to ensure a good parallel efficiency of the global algorithm. After this study, the main remaining difficulty implementation-wise is about the memory requirement of a vector used for initialization. An efficient acceleration operator will also need to be developed. (authors)
Energy Technology Data Exchange (ETDEWEB)
Alday, Luis F.; Genolini, Pietro Benetti; Bullimore, Mathew; Loon, Mark van [Mathematical Institute, University of Oxford, Andrew Wiles Building,Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG (United Kingdom)
2017-04-28
We explore aspects of the correspondence between Seifert 3-manifolds and 3d N=2 supersymmetric theories with a distinguished abelian flavour symmetry. We give a prescription for computing the squashed three-sphere partition functions of such 3d N=2 theories constructed from boundary conditions and interfaces in a 4d N=2{sup ∗} theory, mirroring the construction of Seifert manifold invariants via Dehn surgery. This is extended to include links in the Seifert manifold by the insertion of supersymmetric Wilson-’t Hooft loops in the 4d N=2{sup ∗} theory. In the presence of a mass parameter for the distinguished flavour symmetry, we recover aspects of refined Chern-Simons theory with complex gauge group, and in particular construct an analytic continuation of the S-matrix of refined Chern-Simons theory.
What is 3D good for? A review of human performance on stereoscopic 3D displays
McIntire, John P.; Havig, Paul R.; Geiselman, Eric E.
2012-06-01
This work reviews the human factors-related literature on the task performance implications of stereoscopic 3D displays, in order to point out the specific performance benefits (or lack thereof) one might reasonably expect to observe when utilizing these displays. What exactly is 3D good for? Relative to traditional 2D displays, stereoscopic displays have been shown to enhance performance on a variety of depth-related tasks. These tasks include judging absolute and relative distances, finding and identifying objects (by breaking camouflage and eliciting perceptual "pop-out"), performing spatial manipulations of objects (object positioning, orienting, and tracking), and navigating. More cognitively, stereoscopic displays can improve the spatial understanding of 3D scenes or objects, improve memory/recall of scenes or objects, and improve learning of spatial relationships and environments. However, for tasks that are relatively simple, that do not strictly require depth information for good performance, where other strong cues to depth can be utilized, or for depth tasks that lie outside the effective viewing volume of the display, the purported performance benefits of 3D may be small or altogether absent. Stereoscopic 3D displays come with a host of unique human factors problems including the simulator-sickness-type symptoms of eyestrain, headache, fatigue, disorientation, nausea, and malaise, which appear to effect large numbers of viewers (perhaps as many as 25% to 50% of the general population). Thus, 3D technology should be wielded delicately and applied carefully; and perhaps used only as is necessary to ensure good performance.
Energy Technology Data Exchange (ETDEWEB)
Pei, Du; Ye, Ke [Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, CA, 91125 (United States)
2016-11-02
We test the 3d-3d correspondence for theories that are labeled by Lens spaces. We find a full agreement between the index of the 3d N=2 “Lens space theory” T[L(p,1)] and the partition function of complex Chern-Simons theory on L(p,1). In particular, for p=1, we show how the familiar S{sup 3} partition function of Chern-Simons theory arises from the index of a free theory. For large p, we find that the index of T[L(p,1)] becomes a constant independent of p. In addition, we study T[L(p,1)] on the squashed three-sphere S{sub b}{sup 3}. This enables us to see clearly, at the level of partition function, to what extent G{sub ℂ} complex Chern-Simons theory can be thought of as two copies of Chern-Simons theory with compact gauge group G.
NIF Ignition Target 3D Point Design
Energy Technology Data Exchange (ETDEWEB)
Jones, O; Marinak, M; Milovich, J; Callahan, D
2008-11-05
We have developed an input file for running 3D NIF hohlraums that is optimized such that it can be run in 1-2 days on parallel computers. We have incorporated increasing levels of automation into the 3D input file: (1) Configuration controlled input files; (2) Common file for 2D and 3D, different types of capsules (symcap, etc.); and (3) Can obtain target dimensions, laser pulse, and diagnostics settings automatically from NIF Campaign Management Tool. Using 3D Hydra calculations to investigate different problems: (1) Intrinsic 3D asymmetry; (2) Tolerance to nonideal 3D effects (e.g. laser power balance, pointing errors); and (3) Synthetic diagnostics.
3D accelerator magnet calculations using MAGNUS-3D
International Nuclear Information System (INIS)
Pissanetzky, S.; Miao, Y.
1989-01-01
The steady trend towards increased magnetic and geometric complexity in the design of accelerator magnets has caused a need for reliable 3D computer models and a better understanding of the behavior of magnetic system in three dimensions. The capabilities of the MAGNUS-3D family of programs are ideally suited to solve this class of problems and provide insight into 3D effects. MAGNUS-3D can solve any problem of magnetostatics involving permanent magnets, nonlinear ferromagnetic materials and electric conductors. MAGNUS-3D uses the finite element method and the two-scalar-potentials formulation of Maxwell's equations to obtain the solution, which can then be used interactively to obtain tables of field components at specific points or lines, plots of field lines, function graphs representing a field component plotted against a coordinate along any line in space (such as the beam line), and views of the conductors, the mesh and the magnetic bodies. The magnetic quantities that can be calculated include the force or torque on conductors or magnetic parts, the energy, the flux through a specified surface, line integrals of any field component along any line in space, and the average field or potential harmonic coefficients. We describe the programs with emphasis placed on their use for accelerator magnet design, and present an advanced example of actual calculations. (orig.)
A generalization of the convex Kakeya problem
Ahn, Heekap
2013-09-19
Given a set of line segments in the plane, not necessarily finite, what is a convex region of smallest area that contains a translate of each input segment? This question can be seen as a generalization of Kakeya\\'s problem of finding a convex region of smallest area such that a needle can be rotated through 360 degrees within this region. We show that there is always an optimal region that is a triangle, and we give an optimal Θ(nlogn)-time algorithm to compute such a triangle for a given set of n segments. We also show that, if the goal is to minimize the perimeter of the region instead of its area, then placing the segments with their midpoint at the origin and taking their convex hull results in an optimal solution. Finally, we show that for any compact convex figure G, the smallest enclosing disk of G is a smallest-perimeter region containing a translate of every rotated copy of G. © 2013 Springer Science+Business Media New York.
Stereoscopic 3D graphics generation
Li, Zhi; Liu, Jianping; Zan, Y.
1997-05-01
Stereoscopic display technology is one of the key techniques of areas such as simulation, multimedia, entertainment, virtual reality, and so on. Moreover, stereoscopic 3D graphics generation is an important part of stereoscopic 3D display system. In this paper, at first, we describe the principle of stereoscopic display and summarize some methods to generate stereoscopic 3D graphics. Secondly, to overcome the problems which came from the methods of user defined models (such as inconvenience, long modifying period and so on), we put forward the vector graphics files defined method. Thus we can design more directly; modify the model simply and easily; generate more conveniently; furthermore, we can make full use of graphics accelerator card and so on. Finally, we discuss the problem of how to speed up the generation.
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....
Wright, Lael; Shaw, Daniel; Gaidds, Kimberly; Lyman, Gregory; Sorey, Timothy
2018-01-01
Although solving an engineering design project problem with limited resources or structural capabilities of materials can be part of the challenge, students making their own parts can support creativity. The authors of this article found an exciting solution: 3D printers are not only one of several tools for making but also facilitate a creative…
Directory of Open Access Journals (Sweden)
Roberto Rinaldi
2014-12-01
Full Text Available After an experimental phase of many years, 3D filming is now effective and successful. Improvements are still possible, but the film industry achieved memorable success on 3D movie’s box offices due to the overall quality of its products. Special environments such as space (“Gravity” and the underwater realm look perfect to be reproduced in 3D. “Filming in space” was possible in “Gravity” using special effects and computer graphic. The underwater realm is still difficult to be handled. Underwater filming in 3D was not that easy and effective as filming in 2D, since not long ago. After almost 3 years of research, a French, Austrian and Italian team realized a perfect tool to film underwater, in 3D, without any constrains. This allows filmmakers to bring the audience deep inside an environment where they most probably will never have the chance to be.
3D-Printable Antimicrobial Composite Resins
Yue, Jun; Zhao, Pei; Gerasimov, Jennifer Y.; van de Lagemaat, Marieke; Grotenhuis, Arjen; Rustema-Abbing, Minie; van der Mei, Henny C.; Busscher, Henk J.; Herrmann, Andreas; Ren, Yijin
2015-01-01
3D printing is seen as a game-changing manufacturing process in many domains, including general medicine and dentistry, but the integration of more complex functions into 3D-printed materials remains lacking. Here, it is expanded on the repertoire of 3D-printable materials to include antimicrobial
International Nuclear Information System (INIS)
Illerhaus, Bernhard; Goebbels, Juergen; Onel, Yener; Sauerwein, Christoph
2008-01-01
Mobile tomographs often have the problem that high spatial resolution is impossible owing to the position or setup of the tomograph. While the tree tomograph developed by Messrs. Isotopenforschung Dr. Sauerwein GmbH worked well in practice, it is no longer used as the spatial resolution and measuring time are insufficient for many modern applications. The paper shows that the mechanical base of the method is sufficient for 3D CT measurements with modern detectors and X-ray tubes. CT measurements with very good statistics take less than 10 min. This means that mobile systems can be used, e.g. in examinations of non-transportable cultural objects or monuments. Enhancement of the spatial resolution of mobile tomographs capable of measuring in any position is made difficult by the fact that the tomograph has moving parts and will therefore have weight shifts. With the aid of tomographies whose spatial resolution is far higher than the mechanical accuracy, a correction method is presented for direct integration of the Feldkamp algorithm [de
Djajadiningrat, J.P.
2003-01-01
This article introduces you to the basics of 3D files in general and the 3D Metafile (3DMF), QuickDraw 3D's native 3D format, in particular. It shows how you can use AppleScript to easily convert a raw 3D text file into a 3DMF readable by the QuickDraw 3D Viewer or any other QuickDraw 3D compatible
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...... 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...
Rinaldi, Roberto
2014-01-01
After an experimental phase of many years, 3D filming is now effective and successful. Improvements are still possible, but the film industry achieved memorable success on 3D movie’s box offices due to the overall quality of its products. Special environments such as space (“Gravity” ) and the underwater realm look perfect to be reproduced in 3D. “Filming in space” was possible in “Gravity” using special effects and computer graphic. The underwater realm is still difficult to be handled. Unde...
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'
Dynamic problem of generalized thermoelastic diffusive medium
Energy Technology Data Exchange (ETDEWEB)
Kumar, Rajneesh; Kansal, Tarun [Kurukshetra University, Kurukshetra (India)
2010-01-15
The equations of generalized thermoelastic diffusion, based on the theory of Lord and Shulman with one relaxation time, are derived for anisotropic media with rotation. The variational principle and reciprocity theorem for the governing equations are derived. The propagation of leaky Rayleigh waves in a viscous fluid layer overlying a homogeneous isotropic, generalized thermoelastic diffusive half space with rotating frame of reference is studied
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...
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...
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.
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.
The Esri 3D city information model
International Nuclear Information System (INIS)
Reitz, T; Schubiger-Banz, S
2014-01-01
With residential and commercial space becoming increasingly scarce, cities are going vertical. Managing the urban environments in 3D is an increasingly important and complex undertaking. To help solving this problem, Esri has released the ArcGIS for 3D Cities solution. The ArcGIS for 3D Cities solution provides the information model, tools and apps for creating, analyzing and maintaining a 3D city using the ArcGIS platform. This paper presents an overview of the 3D City Information Model and some sample use cases
General inverse problems for regular variation
DEFF Research Database (Denmark)
Damek, Ewa; Mikosch, Thomas Valentin; Rosinski, Jan
2014-01-01
Regular variation of distributional tails is known to be preserved by various linear transformations of some random structures. An inverse problem for regular variation aims at understanding whether the regular variation of a transformed random object is caused by regular variation of components ...
The Twin Prime Problem and Generalizations
Indian Academy of Sciences (India)
IAS Admin
theory. Though several sophisticated tools were discov- ered, the problem defied many attempts to ... number theory and algebraic geometry. Thus ... goal to discuss some of these below. ..... values of d) ϱ2(d) by setting ϱ2(p) = νp(H) − 1 and.
International Nuclear Information System (INIS)
Hahn, D.; Mery, D.
2003-01-01
In order to evaluate the sensitivity of defect inspection systems, it is convenient to examine simulated data. This gives the possibility to tune the parameters of the inspection method and to test the performance of the system in critical cases. In this paper, a practical method for the simulation of defects in radioscopic images of aluminium castings is presented. The approach simulates only the flaws and not the whole radioscopic image of the object under test. A 3D mesh is used to model a flaw with complex geometry, which is projected and superimposed onto real radioscopic images of a homogeneous object according to the exponential attenuation law for X- rays. The new grey value of a pixel, where the 3D flaw is projected, depends only on four parameters: (a) the grey value of the original X-ray image without flaw; (b) the linear absorption coefficient of the examined material; (c) the maximal thickness observable in the radioscopic image; and (d) the length of the intersection of the 3D flaw with the modelled X-ray beam, that is projected into the pixel. A simulation of a complex flaw modelled as a 3D mesh can be performed in any position of the castings by using the algorithm described in this paper. This allows the evaluation of the performance of defect inspection systems in cases where the detection is known to be difficult. In this paper, we show experimental results on real X-ray images of aluminium wheels, in which 3D flaws like blowholes, cracks and inclusions are simulated
3-D bioprinting law regulation perspectives.
Pashkov, Vitalii; Harkusha, Andrii
Achieved level of technical progress moves us closer and closer to practical use of 3-d bioprinting technologies in real life. Such perspective raise a wide variety of crucial legal issues from the acceptable model of regulation of the science and its' societal effects to problems of the commercialization of the technology and potential restrictions of its use. Some key points on concept of legal regulation of abovementioned sphere is a base of this study. Scientific discussion on 3-D bioprinting, European Union`s and US experience in patenting of 3-D bioprinting technologies, European Medicine Agency (EMA) or the US Food and Drug Administration (FDA) regulations, European Medical Technology Industry Association (EUCOMED) Acts. Article is based on dialectical, comparative, analytic, synthetic and comprehensive research methods. General debate of last few years comes down to an attempt to resolve hesitation between legal attempts for regulation of 3-D biobrinting and concept of complete prohibition of such activities. An adequate response to the mentioned challenge is a reasonable position between some aspects of prohibition and self-regulation, resulting in a moderate number of regulations and standards for developing and marketing. Such regulations may concern an intellectual property (IP) rights, regulation of distribution, premarket restrictions, control mechanism etc. Scientific approach and regulatory settlement of 3-D bioprinting sphere must unite to achieve a fair balance between the interests of humanity and of individuals - on the one hand, and development of science and business benefits for stakeholders - on the other. The main instruments for this must be balanced regulation of intellectual property (IP) rights, regulation of access and distribution, premarket restrictions, control mechanism etc.
DYNA3D2000*, Explicit 3-D Hydrodynamic FEM Program
International Nuclear Information System (INIS)
Lin, J.
2002-01-01
1 - Description of program or function: DYNA3D2000 is a nonlinear explicit finite element code for analyzing 3-D structures and solid continuum. The code is vectorized and available on several computer platforms. The element library includes continuum, shell, beam, truss and spring/damper elements to allow maximum flexibility in modeling physical problems. Many materials are available to represent a wide range of material behavior, including elasticity, plasticity, composites, thermal effects and rate dependence. In addition, DYNA3D has a sophisticated contact interface capability, including frictional sliding, single surface contact and automatic contact generation. 2 - Method of solution: Discretization of a continuous model transforms partial differential equations into algebraic equations. A numerical solution is then obtained by solving these algebraic equations through a direct time marching scheme. 3 - Restrictions on the complexity of the problem: Recent software improvements have eliminated most of the user identified limitations with dynamic memory allocation and a very large format description that has pushed potential problem sizes beyond the reach of most users. The dominant restrictions remain in code execution speed and robustness, which the developers constantly strive to improve
PIXIE3D: An efficient, fully implicit, parallel, 3D extended MHD code for fusion plasma modeling
International Nuclear Information System (INIS)
Chacon, L.
2007-01-01
PIXIE3D is a modern, parallel, state-of-the-art extended MHD code that employs fully implicit methods for efficiency and accuracy. It features a general geometry formulation, and is therefore suitable for the study of many magnetic fusion configurations of interest. PIXIE3D advances the state of the art in extended MHD modeling in two fundamental ways. Firstly, it employs a novel conservative finite volume scheme which is remarkably robust and stable, and demands very small physical and/or numerical dissipation. This is a fundamental requirement when one wants to study fusion plasmas with realistic conductivities. Secondly, PIXIE3D features fully-implicit time stepping, employing Newton-Krylov methods for inverting the associated nonlinear systems. These methods have been shown to be scalable and efficient when preconditioned properly. Novel preconditioned ideas (so-called physics based), which were prototypes in the context of reduced MHD, have been adapted for 3D primitive-variable resistive MHD in PIXIE3D, and are currently being extended to Hall MHD. PIXIE3D is fully parallel, employing PETSc for parallelism. PIXIE3D has been thoroughly benchmarked against linear theory and against other available extended MHD codes on nonlinear test problems (such as the GEM reconnection challenge). We are currently in the process of extending such comparisons to fusion-relevant problems in realistic geometries. In this talk, we will describe both the spatial discretization approach and the preconditioning strategy employed for extended MHD in PIXIE3D. We will report on recent benchmarking studies between PIXIE3D and other 3D extended MHD codes, and will demonstrate its usefulness in a variety of fusion-relevant configurations such as Tokamaks and Reversed Field Pinches. (Author)
Cinema, Fermi Problems and General Education
Efthimiou, C. J.; Llewellyn, R. A.
2007-01-01
During the past few years the authors have developed a new approach to the teaching of physical science, a general education course typically found in the curricula of nearly every college and university. This approach, called "Physics in Films" (Efthimiou and Llewellyn 2006 Phys. Teach. 44 28-33), uses scenes from popular films to illustrate…
3D Printing of Fluid Flow Structures
Taira, Kunihiko; Sun, Yiyang; Canuto, Daniel
2017-01-01
We discuss the use of 3D printing to physically visualize (materialize) fluid flow structures. Such 3D models can serve as a refreshing hands-on means to gain deeper physical insights into the formation of complex coherent structures in fluid flows. In this short paper, we present a general procedure for taking 3D flow field data and producing a file format that can be supplied to a 3D printer, with two examples of 3D printed flow structures. A sample code to perform this process is also prov...
Manabe, Yoshitsugu; Imura, Masataka; Tsuchiya, Masanobu; Yasumuro, Yoshihiro; Chihara, Kunihiro
2003-01-01
Wearable 3D measurement realizes to acquire 3D information of an objects or an environment using a wearable computer. Recently, we can send voice and sound as well as pictures by mobile phone in Japan. Moreover it will become easy to capture and send data of short movie by it. On the other hand, the computers become compact and high performance. And it can easy connect to Internet by wireless LAN. Near future, we can use the wearable computer always and everywhere. So we will be able to send the three-dimensional data that is measured by wearable computer as a next new data. This paper proposes the measurement method and system of three-dimensional data of an object with the using of wearable computer. This method uses slit light projection for 3D measurement and user"s motion instead of scanning system.
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...... important to appreciate the analysis. Before turning to the presentation of preliminary findings and a discussion of 3D digital modelling, it begins, however, with an outline of industry specific ICT strategic issues. Paper type. Multi-site field study...
Energy Technology Data Exchange (ETDEWEB)
Toksoz, M. Nafi
2001-03-31
Completed a theoretical analysis of phase screen propagators to answer several critical questions: the existence of a singularity in the Green's function for the case of a zero vertical wavenumber, the stability and accuracy of such propagators, and the effects of backscattering for large contrast heterogeneous media. The theory is based on separating the wavefield into forescattering and backscattering parts. The approach is robust and appropriate for earth structures with high velocity contrast. This theory also resolves the apparent singularity problem that has persisted in generalized screen propagator formulations. With this formulation we studied the effects of the commonly used approximations as a function of the degree of velocity contrast in the media.
Aspects of defects in 3d-3d correspondence
International Nuclear Information System (INIS)
Gang, Dongmin; Kim, Nakwoo; Romo, Mauricio; Yamazaki, Masahito
2016-01-01
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=2T_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.
Directory of Open Access Journals (Sweden)
R. Catanese
2013-07-01
Full Text Available 3D architectural mapping is a video projection technique that can be done with a survey of a chosen building in order to realize a perfect correspondence between its shapes and the images in projection. As a performative kind of audiovisual artifact, the real event of the 3D mapping is a combination of a registered video animation file with a real architecture. This new kind of visual art is becoming very popular and its big audience success testifies new expressive chances in the field of urban design. My case study has been experienced in Pisa for the Luminara feast in 2012.
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....
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 ...... 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....
Directory of Open Access Journals (Sweden)
Francisco R. Feito Higueruela
2010-04-01
Full Text Available Applications of Geographical Information Systems on several Archeology fields have been increasing during the last years. Recent avances in these technologies make possible to work with more realistic 3D models. In this paper we introduce a new paradigm for this system, the GIS Thetrahedron, in which we define the fundamental elements of GIS, in order to provide a better understanding of their capabilities. At the same time the basic 3D characteristics of some comercial and open source software are described, as well as the application to some samples on archeological researchs
Using a general problem-solving strategy to promote transfer.
Youssef-Shalala, Amina; Ayres, Paul; Schubert, Carina; Sweller, John
2014-09-01
Cognitive load theory was used to hypothesize that a general problem-solving strategy based on a make-as-many-moves-as-possible heuristic could facilitate problem solutions for transfer problems. In four experiments, school students were required to learn about a topic through practice with a general problem-solving strategy, through a conventional problem solving strategy or by studying worked examples. In Experiments 1 and 2 using junior high school students learning geometry, low knowledge students in the general problem-solving group scored significantly higher on near or far transfer tests than the conventional problem-solving group. In Experiment 3, an advantage for a general problem-solving group over a group presented worked examples was obtained on far transfer tests using the same curriculum materials, again presented to junior high school students. No differences between conditions were found in Experiments 1, 2, or 3 using test problems similar to the acquisition problems. Experiment 4 used senior high school students studying economics and found the general problem-solving group scored significantly higher than the conventional problem-solving group on both similar and transfer tests. It was concluded that the general problem-solving strategy was helpful for novices, but not for students that had access to domain-specific knowledge. PsycINFO Database Record (c) 2014 APA, all rights reserved.
M.M. Voormolen (Marco)
2007-01-01
textabstractThree dimensional (3D) echocardiography has recently developed from an experimental technique in the â€™90 towards an imaging modality for the daily clinical practice. This dissertation describes the considerations, implementation, validation and clinical application of a unique
ORMGEN3D, 3-D Crack Geometry FEM Mesh Generator
International Nuclear Information System (INIS)
Bass, B.R.; Bryson, J.W.
1994-01-01
1 - Description of program or function: ORMGEN3D is a finite element mesh generator for computational fracture mechanics analysis. The program automatically generates a three-dimensional finite element model for six different crack geometries. These geometries include flat plates with straight or curved surface cracks and cylinders with part-through cracks on the outer or inner surface. Mathematical or user-defined crack shapes may be considered. The curved cracks may be semicircular, semi-elliptical, or user-defined. A cladding option is available that allows for either an embedded or penetrating crack in the clad material. 2 - Method of solution: In general, one eighth or one-quarter of the structure is modelled depending on the configuration or option selected. The program generates a core of special wedge or collapsed prism elements at the crack front to introduce the appropriate stress singularity at the crack tip. The remainder of the structure is modelled with conventional 20-node iso-parametric brick elements. Element group I of the finite element model consists of an inner core of special crack tip elements surrounding the crack front enclosed by a single layer of conventional brick elements. Eight element divisions are used in a plane orthogonal to the crack front, while the number of element divisions along the arc length of the crack front is user-specified. The remaining conventional brick elements of the model constitute element group II. 3 - Restrictions on the complexity of the problem: Maxima of 5,500 nodes, 4 layers of clad elements
Directory of Open Access Journals (Sweden)
L. V. Eppelbaum
2008-11-01
Full Text Available Thousands of sinkholes have appeared in the Dead Sea (DS coastal area in Israel and Jordan during two last decades. The sinkhole development is recently associated with the buried evaporation karst at the depth of 25–50 m from earth's surface caused by the drop of the DS level at the rate of 0.8–1.0 m/yr. Drop in the Dead Sea level has changed hydrogeological conditions in the subsurface and caused surface to collapse. The pre-existing cavern was detected using microgravity mapping in the Nahal Hever South site where seven sinkholes of 1–2 m diameter had been opened. About 5000 gravity stations were observed in the area of 200×200 m^{2} by the use of Scintrex CG-3M AutoGrav gravimeter. Besides the conventional set of corrections applied in microgravity investigations, a correction for a strong gravity horizontal gradient (DS Transform Zone negative gravity anomaly influence was inserted. As a result, residual gravity anomaly of –(0.08÷0.14 mGal was revealed. The gravity field analysis was supported by resistivity measurements. We applied the Emigma 7.8 gravity software to create the 3-D physical-geological models of the sinkholes development area. The modeling was confirmed by application of the GSFC program developed especially for 3-D combined gravity-magnetic modeling in complicated environments. Computed numerous gravity models verified an effective applicability of the microgravity technology for detection of karst cavities and estimation of their physical-geological parameters. A volume of the karst was approximately estimated as 35 000 m^{3}. The visual analysis of large sinkhole clusters have been forming at the microgravity anomaly site, confirmed the results of microgravity mapping and 3-D modeling.
The Human Mind As General Problem Solver
Gurr, Henry
2011-10-01
Since leaving U Cal Irvine Neutrino Research, I have been a University Physics Teacher, and an Informal Researcher Of Human Functionality. My talk will share what I discovered about the best ways to learn, many of which are regularities that are to be expected from the Neuronal Network Properties announced in the publications of physicist John Joseph Hopfield. Hopfield's Model of mammalian brain-body, provides solid instructive understanding of how best Learn, Solve Problems, Live! With it we understand many otherwise puzzling features of our intellect! Examples Why 1) Analogies and metaphors powerful in class instruction, ditto poems. 2) Best learning done in physical (Hands-On) situations with tight immediate dynamical feedback such as seen in learning to ride bike, drive car, speak language, etc. 3) Some of the best learning happens in seeming random exploration, bump around, trial and error. 4) Scientific discoveries happen, with no apparent effort, at odd moments. 5) Important discoveries DEPEND on considerable frustrating effort, then Flash of Insight AHA EURIKA.
Cevidanes, Lucia; Tucker, Scott; Styner, Martin; Kim, Hyungmin; Chapuis, Jonas; Reyes, Mauricio; Proffit, William; Turvey, Timothy; Jaskolka, Michael
2010-01-01
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 ...
Strong Duality and Optimality Conditions for Generalized Equilibrium Problems
Directory of Open Access Journals (Sweden)
D. H. Fang
2013-01-01
Full Text Available We consider a generalized equilibrium problem involving DC functions. By using the properties of the epigraph of the conjugate functions, some sufficient and/or necessary conditions for the weak and strong duality results and optimality conditions for generalized equilibrium problems are provided.
Problem solving therapy - use and effectiveness in general practice.
Pierce, David
2012-09-01
Problem solving therapy (PST) is one of the focused psychological strategies supported by Medicare for use by appropriately trained general practitioners. This article reviews the evidence base for PST and its use in the general practice setting. Problem solving therapy involves patients learning or reactivating problem solving skills. These skills can then be applied to specific life problems associated with psychological and somatic symptoms. Problem solving therapy is suitable for use in general practice for patients experiencing common mental health conditions and has been shown to be as effective in the treatment of depression as antidepressants. Problem solving therapy involves a series of sequential stages. The clinician assists the patient to develop new empowering skills, and then supports them to work through the stages of therapy to determine and implement the solution selected by the patient. Many experienced GPs will identify their own existing problem solving skills. Learning about PST may involve refining and focusing these skills.
Personal Investigator: A Therapeutic 3D Game for Adolescent Psychotherapy
Coyle, David; Matthews, Mark; Sharry, John; Nisbet, Andy; Doherty, Gavin
2005-01-01
Although mental health problems increase markedly during adolescent years, therapists often find it difficult to engage withadolescents. The majority of disturbed adolescents do not receive professional mental health care and of those who do fewerstill will fully engage with the therapeutic process (Offer et al. 1991; US Surgeon General 1999). Personal Investigator (PI) is a3D computer game specifically designed to help adolescents overcome mental health problems such as depression and helpth...
MAGNUS-3D: Accelerator magnet calculations in 3-dimensions
Pissanetzky, S.
1988-12-01
MAGNUS-3D is a professional finite element code for nonlinear magnetic engineering. MAGNUS-3D can solve numerically any general problem of linear or nonlinear magnetostatics in three dimensions. The problem is formulated in a domain with Dirichlet, Neumann or periodic boundary conditions, that can contain any combination of conductors of any shape in space, nonlinear magnetic materials with magnetic properties specified by magnetization tables, and nonlinear permanent magnets with any given demagnetization curve. MAGNUS-3D uses the two-scalar-potentials formulation of Magnetostatics and the finite element method, has an automatic 3D mesh generator, and advanced post-processing features that include graphics on a variety of supported devices, tabulation, and calculation of design quantities required in Magnetic Engineering. MAGNUS-3D is a general purpose 3D code, but it has been extensively used for accelerator work and many special features required for accelerator engineering have been incorporated into the code. One of such features is the calculation of field harmonic coefficients averaged in the direction of the beam, so important for the design of magnet ends. Another feature is its ability to calculate line integrals of any field component along the direction of the beam, or plot the field as a function of the z coordinate. MAGNUS-3D has found applications to the design of accelerator magnets and spectrometers, steering magnets, wigglers and undulators for free electron lasers, microtrons and magnets for synchrotron light sources, as well as magnets for NMR and medical applications, recording heads and various magnetic devices. There are three more programs closely associated with MAGNUS-3D. MAGNUS-GKS is the graphical postprocessor for the package; it supports a numer of output devices, including color vector or bit map devices. WIRE is an independent program that can calculate the field produced by any configuration of electric conductors in space, at any
Optimizing visual comfort for stereoscopic 3D display based on color-plus-depth signals.
Shao, Feng; Jiang, Qiuping; Fu, Randi; Yu, Mei; Jiang, Gangyi
2016-05-30
Visual comfort is a long-facing problem in stereoscopic 3D (S3D) display. In this paper, targeting to produce S3D content based on color-plus-depth signals, a general framework for depth mapping to optimize visual comfort for S3D display is proposed. The main motivation of this work is to remap the depth range of color-plus-depth signals to a new depth range that is suitable to comfortable S3D display. Towards this end, we first remap the depth range globally based on the adjusted zero disparity plane, and then present a two-stage global and local depth optimization solution to solve the visual comfort problem. The remapped depth map is used to generate the S3D output. We demonstrate the power of our approach on perceptually uncomfortable and comfortable stereoscopic images.
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...... facilitated discussions during the course as well as through a survey distributed to the participating students. The analysis of the experiences shows a mixed picture consisting of both benefits and limits to the experimental technique. A discussion about the applicability of the technique and about...
3D treatment planning systems.
Saw, Cheng B; Li, Sicong
2018-01-01
Three-dimensional (3D) treatment planning systems have evolved and become crucial components of modern radiation therapy. The systems are computer-aided designing or planning softwares that speed up the treatment planning processes to arrive at the best dose plans for the patients undergoing radiation therapy. Furthermore, the systems provide new technology to solve problems that would not have been considered without the use of computers such as conformal radiation therapy (CRT), intensity-modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT). The 3D treatment planning systems vary amongst the vendors and also the dose delivery systems they are designed to support. As such these systems have different planning tools to generate the treatment plans and convert the treatment plans into executable instructions that can be implemented by the dose delivery systems. The rapid advancements in computer technology and accelerators have facilitated constant upgrades and the introduction of different and unique dose delivery systems than the traditional C-arm type medical linear accelerators. The focus of this special issue is to gather relevant 3D treatment planning systems for the radiation oncology community to keep abreast of technology advancement by assess the planning tools available as well as those unique "tricks or tips" used to support the different dose delivery systems. Copyright © 2018 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.
Maintaining and troubleshooting your 3D printer
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
Turovets, Sergei; Volkov, Vasily; Zherdetsky, Aleksej; Prakonina, Alena; Malony, Allen D
2014-01-01
The Electrical Impedance Tomography (EIT) and electroencephalography (EEG) forward problems in anisotropic inhomogeneous media like the human head belongs to the class of the three-dimensional boundary value problems for elliptic equations with mixed derivatives. We introduce and explore the performance of several new promising numerical techniques, which seem to be more suitable for solving these problems. The proposed numerical schemes combine the fictitious domain approach together with the finite-difference method and the optimally preconditioned Conjugate Gradient- (CG-) type iterative method for treatment of the discrete model. The numerical scheme includes the standard operations of summation and multiplication of sparse matrices and vector, as well as FFT, making it easy to implement and eligible for the effective parallel implementation. Some typical use cases for the EIT/EEG problems are considered demonstrating high efficiency of the proposed numerical technique.
Marinin, I. V.; Kabanikhin, S. I.; Krivorotko, O. I.; Karas, A.; Khidasheli, D. G.
2012-04-01
We consider new techniques and methods for earthquake and tsunami related problems, particularly - inverse problems for the determination of tsunami source parameters, numerical simulation of long wave propagation in soil and water and tsunami risk estimations. In addition, we will touch upon the issue of database management and destruction scenario visualization. New approaches and strategies, as well as mathematical tools and software are to be shown. The long joint investigations by researchers of the Institute of Mathematical Geophysics and Computational Mathematics SB RAS and specialists from WAPMERR and Informap have produced special theoretical approaches, numerical methods, and software tsunami and earthquake modeling (modeling of propagation and run-up of tsunami waves on coastal areas), visualization, risk estimation of tsunami, and earthquakes. Algorithms are developed for the operational definition of the origin and forms of the tsunami source. The system TSS numerically simulates the source of tsunami and/or earthquakes and includes the possibility to solve the direct and the inverse problem. It becomes possible to involve advanced mathematical results to improve models and to increase the resolution of inverse problems. Via TSS one can construct maps of risks, the online scenario of disasters, estimation of potential damage to buildings and roads. One of the main tools for the numerical modeling is the finite volume method (FVM), which allows us to achieve stability with respect to possible input errors, as well as to achieve optimum computing speed. Our approach to the inverse problem of tsunami and earthquake determination is based on recent theoretical results concerning the Dirichlet problem for the wave equation. This problem is intrinsically ill-posed. We use the optimization approach to solve this problem and SVD-analysis to estimate the degree of ill-posedness and to find the quasi-solution. The software system we developed is intended to
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
Directory of Open Access Journals (Sweden)
Jan Benacka
2009-06-01
Full Text Available In the article, the formulas for orthographic parallel projection of 3D bodies on computer screen are derived using secondary school vector algebra. The spreadsheet implementation is demonstrated in six applications that project bodies with increasing intricacy – a convex body (cube with non-solved visibility, convex bodies (cube, chapel with solved visibility, a coloured convex body (chapel with solved visibility, and a coloured non-convex body (church with solved visibility. The projections are revolvable in horizontal and vertical plane, and they are changeable in size. The examples show an unusual way of using spreadsheets as a 3D computer graphics tool. The applications can serve as a simple introduction to the general principles of computer graphics, to the graphics with spreadsheets, and as a tool for exercising stereoscopic vision. The presented approach is usable at visualising 3D scenes within some topics of secondary school curricula as solid geometry (angles and distances of lines and planes within simple bodies or analytic geometry in space (angles and distances of lines and planes in E3, and even at university level within calculus at visualising graphs of z = f(x,y functions. Examples are pictured.
Improving automated 3D reconstruction methods via vision metrology
Toschi, Isabella; Nocerino, Erica; Hess, Mona; Menna, Fabio; Sargeant, Ben; MacDonald, Lindsay; Remondino, Fabio; Robson, Stuart
2015-05-01
This paper aims to provide a procedure for improving automated 3D reconstruction methods via vision metrology. The 3D reconstruction problem is generally addressed using two different approaches. On the one hand, vision metrology (VM) systems try to accurately derive 3D coordinates of few sparse object points for industrial measurement and inspection applications; on the other, recent dense image matching (DIM) algorithms are designed to produce dense point clouds for surface representations and analyses. This paper strives to demonstrate a step towards narrowing the gap between traditional VM and DIM approaches. Efforts are therefore intended to (i) test the metric performance of the automated photogrammetric 3D reconstruction procedure, (ii) enhance the accuracy of the final results and (iii) obtain statistical indicators of the quality achieved in the orientation step. VM tools are exploited to integrate their main functionalities (centroid measurement, photogrammetric network adjustment, precision assessment, etc.) into the pipeline of 3D dense reconstruction. Finally, geometric analyses and accuracy evaluations are performed on the raw output of the matching (i.e. the point clouds) by adopting a metrological approach. The latter is based on the use of known geometric shapes and quality parameters derived from VDI/VDE guidelines. Tests are carried out by imaging the calibrated Portable Metric Test Object, designed and built at University College London (UCL), UK. It allows assessment of the performance of the image orientation and matching procedures within a typical industrial scenario, characterised by poor texture and known 3D/2D shapes.
International Nuclear Information System (INIS)
Way, M. J.; Aleinov, I.; Amundsen, David S.; Chandler, M. A.; Genio, A. D. Del; Fujii, Y.; Kelley, M.; Kiang, N. Y.; Sohl, L.; Tsigaridis, K.; Clune, T. L.
2017-01-01
Resolving Orbital and Climate Keys of Earth and Extraterrestrial Environments with Dynamics (ROCKE-3D) is a three-dimensional General Circulation Model (GCM) developed at the NASA Goddard Institute for Space Studies for the modeling of atmospheres of solar system and exoplanetary terrestrial planets. Its parent model, known as ModelE2, is used to simulate modern Earth and near-term paleo-Earth climates. ROCKE-3D is an ongoing effort to expand the capabilities of ModelE2 to handle a broader range of atmospheric conditions, including higher and lower atmospheric pressures, more diverse chemistries and compositions, larger and smaller planet radii and gravity, different rotation rates (from slower to more rapid than modern Earth’s, including synchronous rotation), diverse ocean and land distributions and topographies, and potential basic biosphere functions. The first aim of ROCKE-3D is to model planetary atmospheres on terrestrial worlds within the solar system such as paleo-Earth, modern and paleo-Mars, paleo-Venus, and Saturn’s moon Titan. By validating the model for a broad range of temperatures, pressures, and atmospheric constituents, we can then further expand its capabilities to those exoplanetary rocky worlds that have been discovered in the past, as well as those to be discovered in the future. We also discuss the current and near-future capabilities of ROCKE-3D as a community model for studying planetary and exoplanetary atmospheres.
Way, M. J.; Aleinov, I.; Amundsen, David S.; Chandler, M. A.; Clune, T. L.; Del Genio, A.; Fujii, Y.; Kelley, M.; Kiang, N. Y.; Sohl, L.;
2017-01-01
Resolving Orbital and Climate Keys of Earth and Extraterrestrial Environments with Dynamics (ROCKE-3D) is a three-dimensional General Circulation Model (GCM) developed at the NASA Goddard Institute for Space Studies for the modeling of atmospheres of solar system and exoplanetary terrestrial planets. Its parent model, known as ModelE2, is used to simulate modern Earth and near-term paleo-Earth climates. ROCKE-3D is an ongoing effort to expand the capabilities of ModelE2 to handle a broader range of atmospheric conditions, including higher and lower atmospheric pressures, more diverse chemistries and compositions, larger and smaller planet radii and gravity, different rotation rates (from slower to more rapid than modern Earth's, including synchronous rotation), diverse ocean and land distributions and topographies, and potential basic biosphere functions. The first aim of ROCKE-3D is to model planetary atmospheres on terrestrial worlds within the solar system such as paleo-Earth, modern and paleo-Mars, paleo-Venus, and Saturn's moon Titan. By validating the model for a broad range of temperatures, pressures, and atmospheric constituents, we can then further expand its capabilities to those exoplanetary rocky worlds that have been discovered in the past, as well as those to be discovered in the future. We also discuss the current and near-future capabilities of ROCKE-3D as a community model for studying planetary and exoplanetary atmospheres.
Resolving Orbital and Climate Keys of Earth and Extraterrestrial Environments with Dynamics (ROCKE-3D) 1.0: A General Circulation Model for Simulating the Climates of Rocky Planets
Energy Technology Data Exchange (ETDEWEB)
Way, M. J.; Aleinov, I.; Amundsen, David S.; Chandler, M. A.; Genio, A. D. Del; Fujii, Y.; Kelley, M.; Kiang, N. Y.; Sohl, L.; Tsigaridis, K. [NASA Goddard Institute for Space Studies, New York, NY 10025 (United States); Clune, T. L. [Global Modeling and Assimilation Office, NASA Goddard Space Flight Center (United States)
2017-07-01
Resolving Orbital and Climate Keys of Earth and Extraterrestrial Environments with Dynamics (ROCKE-3D) is a three-dimensional General Circulation Model (GCM) developed at the NASA Goddard Institute for Space Studies for the modeling of atmospheres of solar system and exoplanetary terrestrial planets. Its parent model, known as ModelE2, is used to simulate modern Earth and near-term paleo-Earth climates. ROCKE-3D is an ongoing effort to expand the capabilities of ModelE2 to handle a broader range of atmospheric conditions, including higher and lower atmospheric pressures, more diverse chemistries and compositions, larger and smaller planet radii and gravity, different rotation rates (from slower to more rapid than modern Earth’s, including synchronous rotation), diverse ocean and land distributions and topographies, and potential basic biosphere functions. The first aim of ROCKE-3D is to model planetary atmospheres on terrestrial worlds within the solar system such as paleo-Earth, modern and paleo-Mars, paleo-Venus, and Saturn’s moon Titan. By validating the model for a broad range of temperatures, pressures, and atmospheric constituents, we can then further expand its capabilities to those exoplanetary rocky worlds that have been discovered in the past, as well as those to be discovered in the future. We also discuss the current and near-future capabilities of ROCKE-3D as a community model for studying planetary and exoplanetary atmospheres.
Computational Complexity of Some Problems on Generalized Cellular Automations
Directory of Open Access Journals (Sweden)
P. G. Klyucharev
2012-03-01
Full Text Available We prove that the preimage problem of a generalized cellular automation is NP-hard. The results of this work are important for supporting the security of the ciphers based on the cellular automations.
Procrustes Problems for General, Triangular, and Symmetric Toeplitz Matrices
Directory of Open Access Journals (Sweden)
Juan Yang
2013-01-01
Full Text Available The Toeplitz Procrustes problems are the least squares problems for the matrix equation AX=B over some Toeplitz matrix sets. In this paper the necessary and sufficient conditions are obtained about the existence and uniqueness for the solutions of the Toeplitz Procrustes problems when the unknown matrices are constrained to the general, the triangular, and the symmetric Toeplitz matrices, respectively. The algorithms are designed and the numerical examples show that these algorithms are feasible.
Higher-Order Generalized Invexity in Control Problems
Directory of Open Access Journals (Sweden)
S. K. Padhan
2011-01-01
Full Text Available We introduce a higher-order duality (Mangasarian type and Mond-Weir type for the control problem. Under the higher-order generalized invexity assumptions on the functions that compose the primal problems, higher-order duality results (weak duality, strong duality, and converse duality are derived for these pair of problems. Also, we establish few examples in support of our investigation.
Man, David Wai Kwong; Poon, Wai Sang; Lam, Chow
2013-01-01
People with traumatic brain injury (TBI) often experience cognitive deficits in attention, memory, executive functioning and problem-solving. The purpose of the present research study was to examine the effectiveness of an artificial intelligent virtual reality (VR)-based vocational problem-solving skill training programme designed to enhance employment opportunities for people with TBI. This was a prospective randomized controlled trial (RCT) comparing the effectiveness of the above programme with that of the conventional psycho-educational approach. Forty participants with mild (n = 20) or moderate (n = 20) brain injury were randomly assigned to each training programme. Comparisons of problem-solving skills were performed with the Wisconsin Card Sorting Test, the Tower of London Test and the Vocational Cognitive Rating Scale. Improvement in selective memory processes and perception of memory function were found. Across-group comparison showed that the VR group performed more favourably than the therapist-led one in terms of objective and subjective outcome measures and better vocational outcomes. These results support the potential use of a VR-based approach in memory training in people with MCI. Further VR applications, limitations and future research are described.
A general approach to posterior contraction in nonparametric inverse problems
Knapik, Bartek; Salomond, Jean Bernard
In this paper, we propose a general method to derive an upper bound for the contraction rate of the posterior distribution for nonparametric inverse problems. We present a general theorem that allows us to derive contraction rates for the parameter of interest from contraction rates of the related
Numerical solution of pipe flow problems for generalized Newtonian fluids
International Nuclear Information System (INIS)
Samuelsson, K.
1993-01-01
In this work we study the stationary laminar flow of incompressible generalized Newtonian fluids in a pipe with constant arbitrary cross-section. The resulting nonlinear boundary value problems can be written in a variational formulation and solved using finite elements and the augmented Lagrangian method. The solution of the boundary value problem is obtained by finding a saddle point of the augmented Lagrangian. In the algorithm the nonlinear part of the equations is treated locally and the solution is obtained by iteration between this nonlinear problem and a global linear problem. For the solution of the linear problem we use the SSOR preconditioned conjugate gradient method. The approximating problem is solved on a sequence of adaptively refined grids. A scheme for adjusting the value of the crucial penalization parameter of the augmented Lagrangian is proposed. Applications to pipe flow and a problem from the theory of capacities are given. (author) (34 refs.)
Generalized Nash equilibrium problems, bilevel programming and mpec
Lalitha, CS
2017-01-01
The book discusses three classes of problems: the generalized Nash equilibrium problems, the bilevel problems and the mathematical programming with equilibrium constraints (MPEC). These problems interact through their mathematical analysis as well as their applications. The primary aim of the book is to present the modern tool of variational analysis and optimization, which are used to analyze these three classes of problems. All contributing authors are respected academicians, scientists and researchers from around the globe. These contributions are based on the lectures delivered by experts at CIMPA School, held at the University of Delhi, India, from 25 November–6 December 2013, and peer-reviewed by international experts. The book contains five chapters. Chapter 1 deals with nonsmooth, nonconvex bilevel optimization problems whose feasible set is described by using the graph of the solution set mapping of a parametric optimization problem. Chapter 2 describes a constraint qualification to MPECs considere...
3D Printing and 3D Bioprinting in Pediatrics.
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.
3D Printing and 3D Bioprinting in Pediatrics
Vijayavenkataraman, Sanjairaj; Fuh, Jerry Y H; Lu, Wen Feng
2017-01-01
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.
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
3D radiative transfer in stellar atmospheres
International Nuclear Information System (INIS)
Carlsson, M
2008-01-01
Three-dimensional (3D) radiative transfer in stellar atmospheres is reviewed with special emphasis on the atmospheres of cool stars and applications. A short review of methods in 3D radiative transfer shows that mature methods exist, both for taking into account radiation as an energy transport mechanism in 3D (magneto-) hydrodynamical simulations of stellar atmospheres and for the diagnostic problem of calculating the emergent spectrum in more detail from such models, both assuming local thermodynamic equilibrium (LTE) and in non-LTE. Such methods have been implemented in several codes, and examples of applications are given.
2014-05-01
1 Potential Cost Savings with 3D Printing Combined With 3D Imaging and CPLM for Fleet Maintenance and Revitalization David N. Ford...2014 4. TITLE AND SUBTITLE Potential Cost Savings with 3D Printing Combined With 3D Imaging and CPLM for Fleet Maintenance and Revitalization 5a...Manufacturing ( 3D printing ) 2 Research Context Problem: Learning curve savings forecasted in SHIPMAIN maintenance initiative have not materialized
3D Volume Rendering and 3D Printing (Additive Manufacturing).
Katkar, Rujuta A; Taft, Robert M; Grant, Gerald T
2018-07-01
Three-dimensional (3D) volume-rendered images allow 3D insight into the anatomy, facilitating surgical treatment planning and teaching. 3D printing, additive manufacturing, and rapid prototyping techniques are being used with satisfactory accuracy, mostly for diagnosis and surgical planning, followed by direct manufacture of implantable devices. The major limitation is the time and money spent generating 3D objects. Printer type, material, and build thickness are known to influence the accuracy of printed models. In implant dentistry, the use of 3D-printed surgical guides is strongly recommended to facilitate planning and reduce risk of operative complications. Copyright © 2018 Elsevier Inc. All rights reserved.
3D game environments create professional 3D game worlds
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
Generalized coherent states for the Coulomb problem in one dimension
International Nuclear Information System (INIS)
Nouri, S.
2002-01-01
A set of generalized coherent states for the one-dimensional Coulomb problem in coordinate representation is constructed. At first, we obtain a mapping for proper transformation of the one-dimensional Coulomb problem into a nonrotating four-dimensional isotropic harmonic oscillator in the hyperspherical space, and the generalized coherent states for the one-dimensional Coulomb problem is then obtained in exact closed form. This exactly soluble model can provide an adequate means for a quantum coherency description of the Coulomb problem in one dimension, sample for coherent aspects of the exciton model in one-dimension example in high-temperature superconductivity, semiconductors, and polymers. Also, it can be useful for investigating the coherent scattering of the Coulomb particles in one dimension
International Nuclear Information System (INIS)
Dossett, Jason N.; Moldenhauer, Jacob; Ishak, Mustapha
2011-01-01
We use cosmological constraints from current data sets and a figure of merit approach in order to probe any deviations from general relativity at cosmological scales. The figure of merit approach is used to study and compare the constraining power of various combinations of data sets on the modified gravity (MG) parameters. We use the recently refined HST-COSMOS weak-lensing tomography data, the ISW-galaxy cross correlations from 2MASS and SDSS luminous red galaxy surveys, the matter power spectrum from SDSS-DR7 (MPK), the WMAP7 temperature and polarization spectra, the baryon acoustic oscillations from Two-Degree Field and SDSS-DR7, and the Union2 compilation of type Ia supernovae, in addition to other bounds from Hubble parameter measurements and big bang nucleosynthesis. We use three parametrizations of MG parameters that enter the perturbed field equations. In order to allow for variations of the parameters with the redshift and scale, the first two parametrizations use recently suggested functional forms while the third is based on binning methods. Using the first parametrization, we find that the CMB+ISW+WL combination provides the strongest constraints on the MG parameters followed by CMB+WL or CMB+MPK+ISW. Using the second parametrization or the binning methods, we find that the combination CMB+MPK+ISW consistently provides some of the strongest constraints. This shows that the constraints are parametrization dependent. We find that adding up current data sets does not improve consistently the uncertainties on MG parameters due to tensions between the best-fit MG parameters preferred by different data sets. Furthermore, some functional forms imposed by the parametrizations can lead to an exacerbation of these tensions. Next, unlike some studies that used the CFHTLS lensing data, we do not find any deviation from general relativity using the refined HST-COSMOS data, confirming previous claims in those studies that their result may have been due to some
Wani, M. Arif; Batchelor, Bruce G.
1992-03-01
Deriving generalized representation of 3-D objects for analysis and recognition is a very difficult task. Three types of representations based on type of an object is used in this paper. Objects which have well-defined geometrical shapes are segmented by using a fast edge region based segmentation technique. The segmented image is represented by plan and elevation of each part of the object if the object parts are symmetrical about their central axis. The plan and elevation concept enables representing and analyzing such objects quickly and efficiently. The second type of representation is used for objects having parts which are not symmetrical about their central axis. The segmented surface patches of such objects are represented by the 3-D boundary and the surface features of each segmented surface. Finally, the third type of representation is used for objects which don't have well-defined geometrical shapes (for example a loaf of bread). These objects are represented and analyzed from its features which are derived using a multiscale contour based technique. Anisotropic Gaussian smoothing technique is introduced to segment the contours at various scales of smoothing. A new merging technique is used which enables getting the current best estimate of break points at each scale. This new technique enables elimination of loss of accuracy of localization effects at coarser scales without using scale space tracking approach.
Carter, Luke
2015-01-01
3D printers are a way of producing a 3D model of an item from a digital file. The model builds up in successive layers of material placed by the printer controlled by the information in the computer file. In this article the author argues that 3D printers are one of the greatest technological advances of recent times. He discusses practical uses…
Allahyari, Morehshin; Rourke, Daniel; Rasch, Miriam
The 3D Additivist Cookbook, devised and edited by Morehshin Allahyari & Daniel Rourke, is a free compendium of imaginative, provocative works from over 100 world-leading artists, activists and theorists. The 3D Additivist Cookbook contains .obj and .stl files for the 3D printer, as well as critical
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...
International Nuclear Information System (INIS)
Shinn, J.L.; Yee, H.C.; Uenishi, K.; NASA, Ames Research Center, Moffett Field, CA; Vigyan Research Associates, Inc., Hampton, VA)
1987-01-01
A semiimplicit high-resolution shock-capturing method for multidimensional systems of hyperbolic conservation laws with stiff source terms has been developed by Yee and Shinn (1987). The goal of this work is to extend this method to solve the three-dimensional fully coupled Navier-Stokes equations for a hypersonic chemically reacting flow in generalized coordinates. In this formulation, the global continuity equation was replaced by all the species continuity equations. The shock-capturing technique is a second-order-accurate, symmetric total-variation-diminishing method which accounts fully and directly for the coupling among the fluid and all the species. To verify the current approach, it was implemented into an existing computer code which contained the MacCormack method. Test results for a five-species reacting flow are shown to be oscillation-free around the shock, and the time spent per iteration only doubles when compared to the result using classical way of supplying numerical dissipation. The extra computation is more than justified by the elimination of spurious oscillation and nonlinear instability associated with the classical shock-capturing schemes in computing hypersonic reacting flows. 27 references
Methodology for the Efficient Progressive Distribution and Visualization of 3D Building Objects
Directory of Open Access Journals (Sweden)
Bo Mao
2016-10-01
Full Text Available Three-dimensional (3D, city models have been applied in a variety of fields. One of the main problems in 3D city model utilization, however, is the large volume of data. In this paper, a method is proposed to generalize the 3D building objects in 3D city models at different levels of detail, and to combine multiple Levels of Detail (LODs for a progressive distribution and visualization of the city models. First, an extended structure for multiple LODs of building objects, BuildingTree, is introduced that supports both single buildings and building groups; second, constructive solid geometry (CSG representations of buildings are created and generalized. Finally, the BuildingTree is stored in the NoSQL database MongoDB for dynamic visualization requests. The experimental results indicate that the proposed progressive method can efficiently visualize 3D city models, especially for large areas.
Seismic processing using Parallel 3D FMM
Borlaug, Idar
2007-01-01
This thesis develops and tests 3D Fast Marching Method (FMM) algorithm and apply these to seismic simulations. The FMM is a general method for monotonically advancing fronts, originally developed by Sethian. It calculates the first arrival time for an advancing front or wave. FMM methods are used for a variety of applications including, fatigue cracks in materials, lymph node segmentation in CT images, computing skeletons and centerlines in 3D objects and for finding salt formations in seismi...
Pathways for Learning from 3D Technology
Carrier, L. Mark; Rab, Saira S.; Rosen, Larry D.; Vasquez, Ludivina; Cheever, Nancy A.
2016-01-01
The purpose of this study was to find out if 3D stereoscopic presentation of information in a movie format changes a viewer's experience of the movie content. Four possible pathways from 3D presentation to memory and learning were considered: a direct connection based on cognitive neuroscience research; a connection through "immersion" in that 3D presentations could provide additional sensorial cues (e.g., depth cues) that lead to a higher sense of being surrounded by the stimulus; a connection through general interest such that 3D presentation increases a viewer’s interest that leads to greater attention paid to the stimulus (e.g., "involvement"); and a connection through discomfort, with the 3D goggles causing discomfort that interferes with involvement and thus with memory. The memories of 396 participants who viewed two-dimensional (2D) or 3D movies at movie theaters in Southern California were tested. Within three days of viewing a movie, participants filled out an online anonymous questionnaire that queried them about their movie content memories, subjective movie-going experiences (including emotional reactions and "presence") and demographic backgrounds. The responses to the questionnaire were subjected to path analyses in which several different links between 3D presentation to memory (and other variables) were explored. The results showed there were no effects of 3D presentation, either directly or indirectly, upon memory. However, the largest effects of 3D presentation were on emotions and immersion, with 3D presentation leading to reduced positive emotions, increased negative emotions and lowered immersion, compared to 2D presentations. PMID:28078331
International Nuclear Information System (INIS)
Bergmann, Ryan M.; Vujić, Jasmina L.
2015-01-01
Highlights: • WARP, a GPU-accelerated Monte Carlo neutron transport code, has been developed. • The NVIDIA OptiX high-performance ray tracing library is used to process geometric data. • The unionized cross section representation is modified for higher performance. • Reference remapping is used to keep the GPU busy as neutron batch population reduces. • Reference remapping is done using a key-value radix sort on neutron reaction type. - Abstract: In recent supercomputers, general purpose graphics processing units (GPGPUs) are a significant faction of the supercomputer’s total computational power. GPGPUs have different architectures compared to central processing units (CPUs), and for Monte Carlo neutron transport codes used in nuclear engineering to take advantage of these coprocessor cards, transport algorithms must be changed to execute efficiently on them. WARP is a continuous energy Monte Carlo neutron transport code that has been written to do this. The main thrust of WARP is to adapt previous event-based transport algorithms to the new GPU hardware; the algorithmic choices for all parts of which are presented in this paper. It is found that remapping history data references increases the GPU processing rate when histories start to complete. The main reason for this is that completed data are eliminated from the address space, threads are kept busy, and memory bandwidth is not wasted on checking completed data. Remapping also allows the interaction kernels to be launched concurrently, improving efficiency. The OptiX ray tracing framework and CUDPP library are used for geometry representation and parallel dataset-side operations, ensuring high performance and reliability
Investigation of Free Particle Propagator with Generalized Uncertainty Problem
International Nuclear Information System (INIS)
Hassanabadi, H.; Ghobakhloo, F.
2016-01-01
We consider the Schrödinger equation with a generalized uncertainty principle for a free particle. We then transform the problem into a second-order ordinary differential equation and thereby obtain the corresponding propagator. The result of ordinary quantum mechanics is recovered for vanishing minimal length parameter.
A generalization of the finiteness problem in local cohomology ...
Indian Academy of Sciences (India)
(Math. Sci.) Vol. 119, No. 2, April 2009, pp. 159–164. © Printed in India. A generalization of the finiteness problem in local cohomology modules. AMIR MAFI. Department of Mathematics, University of Kurdistan, P.O. Box 416, Sanandaj, Iran. Institute for Studies in Theoretical Physics and Mathematics, P.O. Box 19395-5746,.
Problem-Based Learning in a General Psychology Course.
Willis, Sandra A.
2002-01-01
Describes the adoption of problem-based learning (PBL) techniques in a general psychology course. States that the instructor used a combination of techniques, including think-pair-share, lecture/discussion, and PBL. Notes means and standard deviations for graded components of PBL format versus lecture/discussion format. (Contains 18 references.)…
Energy-momentum distribution: A crucial problem in general relativity
Sharif, M.; Fatima, T.
2005-01-01
This paper is aimed to elaborate the problem of energy–momentum in general relativity. In this connection, we use the prescriptions of Einstein, Landau–Lifshitz, Papapetrou and Möller to compute the energy–momentum densities for two exact solutions of Einstein field equations. The space–times under
Municipal solid waste management problems: an applied general equilibrium analysis
Bartelings, H.
2003-01-01
Keywords: Environmental policy; General equilibrium modeling; Negishi format; Waste management policies; Market distortions.
About 40% of the entire budget spent on environmental problems in the
Jacobi-Davidson methods for generalized MHD-eigenvalue problems
J.G.L. Booten; D.R. Fokkema; G.L.G. Sleijpen; H.A. van der Vorst (Henk)
1995-01-01
textabstractA Jacobi-Davidson algorithm for computing selected eigenvalues and associated eigenvectors of the generalized eigenvalue problem $Ax = lambda Bx$ is presented. In this paper the emphasis is put on the case where one of the matrices, say the B-matrix, is Hermitian positive definite. The
Czech Academy of Sciences Publication Activity Database
Hnětynková, Iveta; Plešinger, M.; Strakoš, Z.
2015-01-01
Roč. 36, č. 2 (2015), s. 417-434 ISSN 0895-4798 R&D Projects: GA ČR GA13-06684S Grant - others:GA MŠk(CZ) EE2.3.30.0065; GA MŠk(CZ) LL1202 Keywords : total least squares problem * multiple right-hand sides * core problem * Golub-Kahan bidiagonalization * generalized Jacobi matrices Subject RIV: BA - General Mathematics Impact factor: 1.883, year: 2015
Application of Neutrosophic Set Theory in Generalized Assignment Problem
Directory of Open Access Journals (Sweden)
Supriya Kar
2015-09-01
Full Text Available This paper presents the application of Neutrosophic Set Theory (NST in solving Generalized Assignment Problem (GAP. GAP has been solved earlier under fuzzy environment. NST is a generalization of the concept of classical set, fuzzy set, interval-valued fuzzy set, intuitionistic fuzzy set. Elements of Neutrosophic set are characterized by a truth-membership function, falsity and also indeterminacy which is a more realistic way of expressing the parameters in real life problem. Here the elements of the cost matrix for the GAP are considered as neutrosophic elements which have not been considered earlier by any other author. The problem has been solved by evaluating score function matrix and then solving it by Extremum Difference Method (EDM [1] to get the optimal assignment. The method has been demonstrated by a suitable numerical example.
Polymorphic Uncertain Linear Programming for Generalized Production Planning Problems
Directory of Open Access Journals (Sweden)
Xinbo Zhang
2014-01-01
Full Text Available A polymorphic uncertain linear programming (PULP model is constructed to formulate a class of generalized production planning problems. In accordance with the practical environment, some factors such as the consumption of raw material, the limitation of resource and the demand of product are incorporated into the model as parameters of interval and fuzzy subsets, respectively. Based on the theory of fuzzy interval program and the modified possibility degree for the order of interval numbers, a deterministic equivalent formulation for this model is derived such that a robust solution for the uncertain optimization problem is obtained. Case study indicates that the constructed model and the proposed solution are useful to search for an optimal production plan for the polymorphic uncertain generalized production planning problems.
Measuring Visual Closeness of 3-D Models
Gollaz Morales, Jose Alejandro
2012-09-01
Measuring visual closeness of 3-D models is an important issue for different problems and there is still no standardized metric or algorithm to do it. The normal of a surface plays a vital role in the shading of a 3-D object. Motivated by this, we developed two applications to measure visualcloseness, introducing normal difference as a parameter in a weighted metric in Metro’s sampling approach to obtain the maximum and mean distance between 3-D models using 3-D and 6-D correspondence search structures. A visual closeness metric should provide accurate information on what the human observers would perceive as visually close objects. We performed a validation study with a group of people to evaluate the correlation of our metrics with subjective perception. The results were positive since the metrics predicted the subjective rankings more accurately than the Hausdorff distance.
Lightning fast animation in Element 3D
Audronis, Ty
2014-01-01
An easy-to-follow and all-inclusive guide, in which the underlying principles of 3D animation as well as their importance are explained in detail. The lessons are designed to teach you how to think of 3D animation in such a way that you can troubleshoot any problem, or animate any scene that comes your way.If you are a Digital Artist, Animation Artist, or a Game Programmer and you want to become an expert in Element 3D, this is the book for you. Although there are a lot of basics for beginners in this book, it includes some advanced techniques for both animating in Element 3D, and overcoming i
Kulikov, anton I.; Doronila, Paul R.; Nguyen, Viet T.; Jackson, Randal K.; Greene, William M.; Hussey, Kevin J.; Garcia, Christopher M.; Lopez, Christian A.
2013-01-01
Eyes on the Earth 3D software gives scientists, and the general public, a realtime, 3D interactive means of accurately viewing the real-time locations, speed, and values of recently collected data from several of NASA's Earth Observing Satellites using a standard Web browser (climate.nasa.gov/eyes). Anyone with Web access can use this software to see where the NASA fleet of these satellites is now, or where they will be up to a year in the future. The software also displays several Earth Science Data sets that have been collected on a daily basis. This application uses a third-party, 3D, realtime, interactive game engine called Unity 3D to visualize the satellites and is accessible from a Web browser.
3-D Whole-Core Transport Calculation with 3D/2D Rotational Plane Slicing Method
Energy Technology Data Exchange (ETDEWEB)
Yoo, Han Jong; Cho, Nam Zin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)
2014-10-15
Use of the method of characteristics (MOC) is very popular due to its capability of heterogeneous geometry treatment and widely used for 2-D core calculation, but direct extension of MOC to 3-D core is not so attractive due to huge calculational cost. 2-D/1-D fusion method was very successful for 3-D calculation of current generation reactor types (highly heterogeneous in radial direction but piece-wise homogeneous in axial direction). In this paper, 2-D MOC concept is extended to 3-D core calculation with little modification of an existing 2-D MOC code. The key idea is to suppose 3-D geometry as a set of many 2-D planes like a phone-directory book. Dividing 3-D structure into a large number of 2-D planes and solving each plane with a simple 2-D SN transport method would give the solution of a 3-D structure. This method was developed independently at KAIST but it is found that this concept is similar with that of 'plane tracing' in the MCCG-3D code. The method developed was tested on the 3-D C5G7 OECD/NEA benchmark problem and compared with the 2-D/1-D fusion method. Results show that the proposed method is worth investigating further. A new approach to 3-D whole-core transport calculation is described and tested. By slicing 3-D structure along characteristic planes and solving each 2-D plane problem, we can get 3-D solution. The numerical test results indicate that the new method is comparable with the 2D/1D fusion method and outperforms other existing methods. But more fair comparison should be done in similar discretization level.
Fostering Persistence: 3D Printing and the Unforeseen Impact on Equity
FitzPatrick, Daniel L.; Dominguez, Victoria S.
2017-01-01
Teaching persistence and problem solving must begin with selecting a problem that can be solved mathematically, that allows for multiple methods of solving, and that generally captures the attention and curiosity of the student (Marcus and Fey 2003; NCTM 1991; Van de Walle 2003). This article shows how a STEM three-dimensional (3D) printing…
Stochastic programming problems with generalized integrated chance constraints
Czech Academy of Sciences Publication Activity Database
Branda, Martin
2012-01-01
Roč. 61, č. 8 (2012), s. 949-968 ISSN 0233-1934 R&D Projects: GA ČR GAP402/10/1610 Grant - others:SVV(CZ) 261315/2010 Institutional support: RVO:67985556 Keywords : chance constraints * integrated chance constraints * penalty functions * sample approximations * blending problem Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.707, year: 2012 http://library.utia.cas.cz/separaty/2012/E/branda-stochastic programming problems with generalized integrated.pdf
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.
3D Elevation Program—Virtual USA in 3D
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.
3D IBFV : hardware-accelerated 3D flow visualization
Telea, A.C.; Wijk, van J.J.
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 presented by van Wijk (2001) for 2D flow visualization in two main directions. First, we decompose the 3D
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
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...
Hanafy, Sherif M.
2014-01-01
Objective: Collect 3D seismic data at Qademah Fault location to 1. 3D traveltime tomography 2. 3D surface wave migration 3. 3D phase velocity 4. Possible reflection processing Acquisition Date: 26 – 28 September 2014 Acquisition Team: Sherif, Kai, Mrinal, Bowen, Ahmed Acquisition Layout: We used 288 receiver arranged in 12 parallel lines, each line has 24 receiver. Inline offset is 5 m and crossline offset is 10 m. One shot is fired at each receiver location. We use the 40 kgm weight drop as seismic source, with 8 to 15 stacks at each shot location.
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....
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
A New Inexact Inverse Subspace Iteration for Generalized Eigenvalue Problems
Directory of Open Access Journals (Sweden)
Fatemeh Mohammad
2014-05-01
Full Text Available In this paper, we represent an inexact inverse subspace iteration method for computing a few eigenpairs of the generalized eigenvalue problem $Ax = \\lambda Bx$[Q.~Ye and P.~Zhang, Inexact inverse subspace iteration for generalized eigenvalue problems, Linear Algebra and its Application, 434 (2011 1697-1715]. In particular, the linear convergence property of the inverse subspace iteration is preserved.
Teknologi 3D dalam Proses Pembuatan Komik
Directory of Open Access Journals (Sweden)
Johanes Baptista Permadi
2011-04-01
Full Text Available Comic has been people’s favorite since 1930. As the growth of years and technology, the demands in designing comic were also increasing. To fulfill the demands, comic authors spent their times to draw so that they have no time to discover other element besides technical. Therefore, it is important if the comic author helped by 3D technology to accelerate technical process so that the comic authors will get extra time to develop other elements like concept and story. Data is gathered from interviews with both semi-professional and professional comic authors who are having problems being solved. Solving problems are conducted by using 3D software to draw picture of distorted space. And then two semi-professional comic authors will try to draw distorted space in tracing the picture from 3D software to see how many times needed to draw hard part traditionally.
3D face analysis for demographic biometrics
Energy Technology Data Exchange (ETDEWEB)
Tokola, Ryan A [ORNL; Mikkilineni, Aravind K [ORNL; Boehnen, Chris Bensing [ORNL
2015-01-01
Despite being increasingly easy to acquire, 3D data is rarely used for face-based biometrics applications beyond identification. Recent work in image-based demographic biometrics has enjoyed much success, but these approaches suffer from the well-known limitations of 2D representations, particularly variations in illumination, texture, and pose, as well as a fundamental inability to describe 3D shape. This paper shows that simple 3D shape features in a face-based coordinate system are capable of representing many biometric attributes without problem-specific models or specialized domain knowledge. The same feature vector achieves impressive results for problems as diverse as age estimation, gender classification, and race classification.
Towards next generation 3D cameras
Gupta, Mohit
2017-03-01
We are in the midst of a 3D revolution. Robots enabled by 3D cameras are beginning to autonomously drive cars, perform surgeries, and manage factories. However, when deployed in the real-world, these cameras face several challenges that prevent them from measuring 3D shape reliably. These challenges include large lighting variations (bright sunlight to dark night), presence of scattering media (fog, body tissue), and optically complex materials (metal, plastic). Due to these factors, 3D imaging is often the bottleneck in widespread adoption of several key robotics technologies. I will talk about our work on developing 3D cameras based on time-of-flight and active triangulation that addresses these long-standing problems. This includes designing `all-weather' cameras that can perform high-speed 3D scanning in harsh outdoor environments, as well as cameras that recover shape of objects with challenging material properties. These cameras are, for the first time, capable of measuring detailed (robotic inspection and assembly systems.
Problem drinking - detection and assessment in general practice.
Demirkol, Apo; Haber, Paul; Conigrave, Katherine
2011-08-01
Alcohol has long been an integral part of the social life of many Australians. However, alcohol is associated with significant harm to drinkers, and also to nondrinkers. This article explores the role of the general practitioner in the detection and assessment of problem drinking. Excessive alcohol use is a major public health problem and the majority of people who drink excessively go undetected. General practitioners are in a good position to detect excessive alcohol consumption; earlier intervention can help improve outcomes. AUDIT-C is an effective screening tool for the detection of problem drinking. National Health and Medical Research Council guidelines suggest that no more than two standard drinks on each occasion will keep lifetime risk of death from alcohol related disease or injury at a low level. Once an alcohol problem is detected it is important to assess for alcohol dependence, other substance use, motivation to change, psychiatric comorbidities and examination and investigation findings that may be associated with excessive alcohol use. A comprehensive assessment of the impact and risk of harm of the patient's drinking to themselves and others is vital, and may require several consultations.
AUTOMATIC 3D MAPPING USING MULTIPLE UNCALIBRATED CLOSE RANGE IMAGES
Directory of Open Access Journals (Sweden)
M. Rafiei
2013-09-01
Full Text Available Automatic three-dimensions modeling of the real world is an important research topic in the geomatics and computer vision fields for many years. By development of commercial digital cameras and modern image processing techniques, close range photogrammetry is vastly utilized in many fields such as structure measurements, topographic surveying, architectural and archeological surveying, etc. A non-contact photogrammetry provides methods to determine 3D locations of objects from two-dimensional (2D images. Problem of estimating the locations of 3D points from multiple images, often involves simultaneously estimating both 3D geometry (structure and camera pose (motion, it is commonly known as structure from motion (SfM. In this research a step by step approach to generate the 3D point cloud of a scene is considered. After taking images with a camera, we should detect corresponding points in each two views. Here an efficient SIFT method is used for image matching for large baselines. After that, we must retrieve the camera motion and 3D position of the matched feature points up to a projective transformation (projective reconstruction. Lacking additional information on the camera or the scene makes the parallel lines to be unparalleled. The results of SfM computation are much more useful if a metric reconstruction is obtained. Therefor multiple views Euclidean reconstruction applied and discussed. To refine and achieve the precise 3D points we use more general and useful approach, namely bundle adjustment. At the end two real cases have been considered to reconstruct (an excavation and a tower.
Lonigan, Christopher J; Spiegel, Jamie A; Goodrich, J Marc; Morris, Brittany M; Osborne, Colleen M; Lerner, Matthew D; Phillips, Beth M
2017-11-01
Findings from prior research have consistently indicated significant associations between self-regulation and externalizing behaviors. Significant associations have also been reported between children's language skills and both externalizing behaviors and self-regulation. Few studies to date, however, have examined these relations longitudinally, simultaneously, or with respect to unique clusters of externalizing problems. The current study examined the influence of preschool self-regulation on general and specific externalizing behavior problems in early elementary school and whether these relations were independent of associations between language, self-regulation, and externalizing behaviors in a sample of 815 children (44% female). Additionally, given a general pattern of sex differences in the presentations of externalizing behavior problems, self-regulation, and language skills, sex differences for these associations were examined. Results indicated unique relations of preschool self-regulation and language with both general externalizing behavior problems and specific problems of inattention. In general, self-regulation was a stronger longitudinal correlate of externalizing behavior for boys than it was for girls, and language was a stronger longitudinal predictor of hyperactive/impulsive behavior for girls than it was for boys.
3D Viscoelastic Traction Force Microscopy
Toyjanova, Jennet; Hannen, Erin; Bar-Kochba, Eyal; Darling, Eric M.; Henann, David L.; Franck, Christian
2014-01-01
Native cell-material interactions occur on materials differing in their structural composition, chemistry, and physical compliance. While the last two decades have shown the importance of traction forces during cell-material interactions, they have been almost exclusively presented on purely elastic in-vitro materials. Yet, most bodily tissue materials exhibit some level of viscoelasticity, which could play an important role in how cells sense and transduce tractions. To expand the realm of cell traction measurements and to encompass all materials from elastic to viscoelastic, this paper presents a general, and comprehensive approach for quantifying 3D cell tractions in viscoelastic materials. This methodology includes the experimental characterization of the time-dependent material properties for any viscoelastic material with the subsequent mathematical implementation of the determined material model into a 3D traction force microscopy (3D TFM) framework. Utilizing this new 3D viscoelastic TFM (3D VTFM) approach, we quantify the influence of viscosity on the overall material traction calculations and quantify the error associated with omitting time-dependent material effects, as is the case for all other TFM formulations. We anticipate that the 3D VTFM technique will open up new avenues of cell-material investigations on even more physiologically relevant time-dependent materials including collagen and fibrin gels. PMID:25170569
Endodontic applications of 3D printing.
Anderson, J; Wealleans, J; Ray, J
2018-02-27
Computer-aided design (CAD) and computer-aided manufacturing (CAM) technologies can leverage cone beam computed tomography data for production of objects used in surgical and nonsurgical endodontics and in educational settings. The aim of this article was to review all current applications of 3D printing in endodontics and to speculate upon future directions for research and clinical use within the specialty. A literature search of PubMed, Ovid and Scopus was conducted using the following terms: stereolithography, 3D printing, computer aided rapid prototyping, surgical guide, guided endodontic surgery, guided endodontic access, additive manufacturing, rapid prototyping, autotransplantation rapid prototyping, CAD, CAM. Inclusion criteria were articles in the English language documenting endodontic applications of 3D printing. Fifty-one articles met inclusion criteria and were utilized. The endodontic literature on 3D printing is generally limited to case reports and pre-clinical studies. Documented solutions to endodontic challenges include: guided access with pulp canal obliteration, applications in autotransplantation, pre-surgical planning and educational modelling and accurate location of osteotomy perforation sites. Acquisition of technical expertise and equipment within endodontic practices present formidable obstacles to widespread deployment within the endodontic specialty. As knowledge advances, endodontic postgraduate programmes should consider implementing 3D printing into their curriculums. Future research directions should include clinical outcomes assessments of treatments employing 3D printed objects. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.
On drawing complicated 3D surfaces
International Nuclear Information System (INIS)
Nikitin, I.N.; Talanov, V.V.
1994-01-01
The problem of constructing images of complicated 3D surfaces - world sheet of strings is considered. The world sheet representation in the form of a frame of points determined with a specified supporting curve is described. The images of the world sheets of free string are constructed using various graphical technologies. 15 refs., 6 figs
An Enhanced Genetic Algorithm for the Generalized Traveling Salesman Problem
Directory of Open Access Journals (Sweden)
H. Jafarzadeh
2017-12-01
Full Text Available The generalized traveling salesman problem (GTSP deals with finding the minimum-cost tour in a clustered set of cities. In this problem, the traveler is interested in finding the best path that goes through all clusters. As this problem is NP-hard, implementing a metaheuristic algorithm to solve the large scale problems is inevitable. The performance of these algorithms can be intensively promoted by other heuristic algorithms. In this study, a search method is developed that improves the quality of the solutions and competition time considerably in comparison with Genetic Algorithm. In the proposed algorithm, the genetic algorithms with the Nearest Neighbor Search (NNS are combined and a heuristic mutation operator is applied. According to the experimental results on a set of standard test problems with symmetric distances, the proposed algorithm finds the best solutions in most cases with the least computational time. The proposed algorithm is highly competitive with the published until now algorithms in both solution quality and running time.
Directory of Open Access Journals (Sweden)
Yukinori Kawae
2016-12-01
Full Text Available In 2015, in collaboration with the Czech Institute of Egyptology, we, a Japanese consortium, initiated the Abusir 3D Survey (A-3DS for the 3D documentation of the site’s pyramids, which have not been updated since the time of the architectural investigations of Vito Maragioglio and Celeste Rinaldi in the 1960s to the 1970s. The first season of our project focused on the exterior of Neferirkare’s pyramid, the largest pyramid at Abusir. By developing a strategic mathematical 3D survey plan, step-by-step 3D documentation to suit specific archaeological needs, and producing a new display method for the 3D data, we successfully measured the dimensions of the pyramid in a cost-effective way.
Advanced 3-D Ultrasound Imaging
DEFF Research Database (Denmark)
Rasmussen, Morten Fischer
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...... a channel limited 2-D transducer array and the conventional 3-D beamforming technique, Parallel Beamforming. The first part of the scientific contributions demonstrate that 3-D synthetic aperture imaging achieves a better image quality than the Parallel Beamforming technique. Data were obtained using both...
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...... are (vx, vy, vz) = (-0.03, 95, 1.0) ± (9, 6, 1) cm/s compared with the expected (0, 96, 0) cm/s. Afterwards, 3D vector flow images from a cross-sectional plane of the vessel are presented. The out of plane velocities exhibit the expected 2D circular-symmetric parabolic shape. The experimental results...... verify that the 3D TO method estimates the complete 3D velocity vectors, and that the method is suitable for 3D vector flow imaging....
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.
E3D, 3-D Elastic Seismic Wave Propagation Code
International Nuclear Information System (INIS)
Larsen, S.; Harris, D.; Schultz, C.; Maddix, D.; Bakowsky, T.; Bent, L.
2004-01-01
1 - Description of program or function: E3D is capable of simulating seismic wave propagation in a 3D heterogeneous earth. Seismic waves are initiated by earthquake, explosive, and/or other sources. These waves propagate through a 3D geologic model, and are simulated as synthetic seismograms or other graphical output. 2 - Methods: The software simulates wave propagation by solving the elasto-dynamic formulation of the full wave equation on a staggered grid. The solution scheme is 4-order accurate in space, 2-order accurate in time
Butterfly effect in 3D gravity
Qaemmaqami, Mohammad M.
2017-11-01
We study the butterfly effect by considering shock wave solutions near the horizon of the anti-de Sitter black hole in some three-dimensional gravity models including 3D Einstein gravity, minimal massive 3D gravity, new massive gravity, generalized massive gravity, Born-Infeld 3D gravity, and new bigravity. We calculate the butterfly velocities of these models and also we consider the critical points and different limits in some of these models. By studying the butterfly effect in the generalized massive gravity, we observe a correspondence between the butterfly velocities and right-left moving degrees of freedom or the central charges of the dual 2D conformal field theories.
3D gaze tracking system for NVidia 3D Vision®.
Wibirama, Sunu; Hamamoto, Kazuhiko
2013-01-01
Inappropriate parallax setting in stereoscopic content generally causes visual fatigue and visual discomfort. To optimize three dimensional (3D) effects in stereoscopic content by taking into account health issue, understanding how user gazes at 3D direction in virtual space is currently an important research topic. In this paper, we report the study of developing a novel 3D gaze tracking system for Nvidia 3D Vision(®) to be used in desktop stereoscopic display. We suggest an optimized geometric method to accurately measure the position of virtual 3D object. Our experimental result shows that the proposed system achieved better accuracy compared to conventional geometric method by average errors 0.83 cm, 0.87 cm, and 1.06 cm in X, Y, and Z dimensions, respectively.
3D analysis of semiconductor devices: A combination of 3D imaging and 3D elemental analysis
Fu, Bianzhu; Gribelyuk, Michael A.
2018-04-01
3D analysis of semiconductor devices using a combination of scanning transmission electron microscopy (STEM) Z-contrast tomography and energy dispersive spectroscopy (EDS) elemental tomography is presented. 3D STEM Z-contrast tomography is useful in revealing the depth information of the sample. However, it suffers from contrast problems between materials with similar atomic numbers. Examples of EDS elemental tomography are presented using an automated EDS tomography system with batch data processing, which greatly reduces the data collection and processing time. 3D EDS elemental tomography reveals more in-depth information about the defect origin in semiconductor failure analysis. The influence of detector shadowing and X-rays absorption on the EDS tomography's result is also discussed.
3-D image reconstruction in radiology
International Nuclear Information System (INIS)
Grangeat, P.
1999-01-01
In this course, we present highlights on fully 3-D image reconstruction algorithms used in 3-D X-ray Computed Tomography (3-D-CT) and 3-D Rotational Radiography (3-D-RR). We first consider the case of spiral CT with a one-row detector. Starting from the 2-D fan-beam inversion formula for a circular trajectory, we introduce spiral CT 3-D image reconstruction algorithm using axial interpolation for each transverse slice. In order to improve the X-ray detection efficiency and to speed the acquisition process, the future is to use multi-row detectors associated with small angle cone-beam geometry. The generalization of the 2-D fan-beam image reconstruction algorithm to cone beam defined direct inversion formula referred as Feldkamp's algorithm for a circular trajectory and Wang's algorithm for a spiral trajectory. However, large area detectors does exist such as Radiological Image Intensifiers or in a near future solid state detectors. To get a larger zoom effect, it defines a cone-beam geometry associated with a large aperture angle. For this case, we introduce indirect image reconstruction algorithm by plane re-binning in the Radon domain. We will present some results from a prototype MORPHOMETER device using the RADON reconstruction software. Lastly, we consider the special case of 3-D Rotational Digital Subtraction Angiography with a restricted number of views. We introduce constraint optimization algorithm using quadratic, entropic or half-quadratic constraints. Generalized ART (Algebraic Reconstruction Technique) iterative reconstruction algorithm can be derived from the Bregman algorithm. We present reconstructed vascular trees from a prototype MORPHOMETER device. (author)
A Generalized Cauchy Distribution Framework for Problems Requiring Robust Behavior
Directory of Open Access Journals (Sweden)
Carrillo RafaelE
2010-01-01
Full Text Available Statistical modeling is at the heart of many engineering problems. The importance of statistical modeling emanates not only from the desire to accurately characterize stochastic events, but also from the fact that distributions are the central models utilized to derive sample processing theories and methods. The generalized Cauchy distribution (GCD family has a closed-form pdf expression across the whole family as well as algebraic tails, which makes it suitable for modeling many real-life impulsive processes. This paper develops a GCD theory-based approach that allows challenging problems to be formulated in a robust fashion. Notably, the proposed framework subsumes generalized Gaussian distribution (GGD family-based developments, thereby guaranteeing performance improvements over traditional GCD-based problem formulation techniques. This robust framework can be adapted to a variety of applications in signal processing. As examples, we formulate four practical applications under this framework: (1 filtering for power line communications, (2 estimation in sensor networks with noisy channels, (3 reconstruction methods for compressed sensing, and (4 fuzzy clustering.
Building 3D models with modo 701
García, Juan Jiménez
2013-01-01
The book will focus on creating a sample application throughout the book, building gradually from chapter to chapter.If you are new to the 3D world, this is the key to getting started with a modern software in the modern visualization industry. Only minimal previous knowledge is needed.If you have some previous knowledge about 3D content creation, you will find useful tricks that will differentiate the learning experience from a typical user manual from this, a practical guide concerning the most common problems and situations and how to solve them.
A General Solution Framework for Component-Commonality Problems
Directory of Open Access Journals (Sweden)
Nils Boysen
2009-05-01
Full Text Available Component commonality - the use of the same version of a component across multiple products - is being increasingly considered as a promising way to offer high external variety while retaining low internal variety in operations. However, increasing commonality has both positive and negative cost effects, so that optimization approaches are required to identify an optimal commonality level. As components influence to a greater or lesser extent nearly every process step along the supply chain, it is not surprising that a multitude of diverging commonality problems is being investigated in literature, each of which are developing a specific algorithm designed for the respective commonality problem being considered. The paper on hand aims at a general framework which is flexible and efficient enough to be applied to a wide range of commonality problems. Such a procedure based on a two-stage graph approach is presented and tested. Finally, flexibility of the procedure is shown by customizing the framework to account for different types of commonality problems.
Generalized Artificial Life Structure for Time-dependent Problems
Institute of Scientific and Technical Information of China (English)
TSAU Minhe; KAO Weiwen; CHANG Albert
2009-01-01
In recent years, more attention has been paid on artificial life researches. Artificial life(AL) is a research on regulating gene parameters of digital organisms under complicated problematic environments through natural selections and evolutions to achieve the final emergence of intelligence. Most recent studies focused on solving certain real problems by artificial life methods, yet without much address on the AL life basic mechanism. The real problems are often very complicated, and the proposed methods sometimes seem too simple to handle those problems. This study proposed a new approach in AL research, named "generalized artificial life structure(GALS)", in which the traditional "gene bits" in genetic algorithms is first replaced by "gene parameters", which could appear anywhere in GALS. A modeling procedure is taken to normalize the input data, and AL "tissue" is innovated to make AL more complex. GALS is anticipated to contribute significantly to the fitness of AL evolution. The formation of"tissue" begins with some different AL basic cells, and then tissue is produced by the casual selections of one or several of these cells. As a result, the gene parameters, represented by "tissues", could become highly diversified. This diversification should have obvious effects on improving gene fitness. This study took the innovative method of GALS in a stock forecasting problem under a carefully designed manipulating platform. And the researching results verify that the GALS is successful in improving the gene evolution fitness.
The problem of time quantum mechanics versus general relativity
Anderson, Edward
2017-01-01
This book is a treatise on time and on background independence in physics. It first considers how time is conceived of in each accepted paradigm of physics: Newtonian, special relativity, quantum mechanics (QM) and general relativity (GR). Substantial differences are moreover uncovered between what is meant by time in QM and in GR. These differences jointly source the Problem of Time: Nine interlinked facets which arise upon attempting concurrent treatment of the QM and GR paradigms, as is required in particular for a background independent theory of quantum gravity. A sizeable proportion of current quantum gravity programs - e.g. geometrodynamical and loop quantum gravity approaches to quantum GR, quantum cosmology, supergravity and M-theory - are background independent in this sense. This book's foundational topic is thus furthermore of practical relevance in the ongoing development of quantum gravity programs. This book shows moreover that eight of the nine facets of the Problem of Time already occur upon ...
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
Spectrum of general surgical problems in the developmentally disabled adults
International Nuclear Information System (INIS)
Khalid, K.; Al-Salamah, Saleh M.
2006-01-01
This study highlights the spectrum of general surgical problems necessitating admission on intellectually disabled adult patients. Problems encountered in the management and the ways to overcome various difficulties are highlighted. Prospective collection of data on 63 consecutive developmentally disabled adult patients admitted to the Department of General Surgery, Riyadh Medical Complex (RMC), Riyadh, Kingdom of Saudi Arabia for various indications from January 2000 through December 2004. Demographic details, clinical presentation, diagnostic modalities, associated physical and neurological disabilities, coexisting medical condition, treatment options, morbidity and mortality were analyzed. Various difficulties encountered during the management and mean to overcome these problems are addressed. Sixty-three patients accounted for 71 admissions. Mean age was 26.7 years with a male preponderance (4.25:1). Fifty-four patients were admitted for various emergency conditions. History of pica could be obtained in 33% of the cases. Twenty-seven patients were admitted for acute abdomen. Volvulus of the colon (22.2%) and pseudo-obstruction (18.5%) were the most common causes of acute abdomen. Twenty-one patients were admitted with upper gastrointestinal bleeding. Reflux esophagitis was the most common cause of bleeding (62%). Overall morbidity was 41% for emergency admissions and 22% for elective surgery. Hospital mortality was 21.4% for emergency surgery. There was no death in elective cases. Developmentally disabled patients comprise a special class of patients with peculiar management problems. The treating clinician should be aware of various unexpected conditions not found as frequently in the normal patient population. Apparent lack of pain does not exclude an acute emergency. Possible surgical condition should be suspected if there is vomiting, abdominal distension, fever, increased irritability of recent onset. Male gender and history of pica are added risk factors
Directory of Open Access Journals (Sweden)
X. Zhao
2012-01-01
Full Text Available A combined interior point homotopy continuation method is proposed for solving general multiobjective programming problem. We prove the existence and convergence of a smooth homotopy path from almost any interior initial interior point to a solution of the KKT system under some basic assumptions.
Non-integrability of the generalized spring-pendulum problem
International Nuclear Information System (INIS)
Maciejewski, Andrzej J; Przybylska, Maria; Weil, Jacques-Arthur
2004-01-01
We investigate a generalization of the three-dimensional spring-pendulum system. The problem depends on two real parameters (k, a), where k is the Young modulus of the spring and a describes the nonlinearity of elastic forces. We show that this system is not integrable when k ≠ -a. We carefully investigated the case k = -a when the necessary condition for integrability given by the Morales-Ruiz-Ramis theory is satisfied. We discuss an application of the higher order variational equations for proving the non-integrability in this case
"Handling" seismic hazard: 3D printing of California Faults
Kyriakopoulos, C.; Potter, M.; Richards-Dinger, K. B.
2017-12-01
As earth scientists, we face the challenge of how to explain and represent our work and achievements to the general public. Nowadays, this problem is partially alleviated by the use of modern visualization tools such as advanced scientific software (Paraview.org), high resolution monitors, elaborate video simulations, and even 3D Virtual Reality goggles. However, the ability to manipulate and examine a physical object in 3D is still an important tool to connect better with the public. For that reason, we are presenting a scaled 3D printed version of the complex network of earthquake faults active in California based on that used by the Uniform California Earthquake Rupture Forecast 3 (UCERF3) (Field et al., 2013). We start from the fault geometry in the UCERF3.1 deformation model files. These files contain information such as the coordinates of the surface traces of the faults, dip angle, and depth extent. The fault specified in the above files are triangulated at 1km resolution and exported as a facet (.fac) file. The facet file is later imported into the Trelis 15.1 mesh generator (csimsoft.com). We use Trelis to perform the following three operations: First, we scale down the model so that 100 mm corresponds to 100km. Second, we "thicken" the walls of the faults; wall thickness of at least 1mm is necessary in 3D printing. We thicken fault geometry by 1mm on each side of the faults for a total of 2mm thickness. Third, we break down the model into parts that will fit the printing bed size ( 25 x 20mm). Finally, each part is exported in stereolithography format (.stl). For our project, we are using the 3D printing facility within the Creat'R Lab in the UC Riverside Orbach Science Library. The 3D printer is a MakerBot Replicator Desktop, 5th Generation. The resolution of print is 0.2mm (Standard quality). The printing material is the MakerBot PLA Filament, 1.75 mm diameter, large Spool, green. The most complex part of the display model requires approximately 17
This collaborative grant is developing 3D models of both mouse and human biology to investigate aspects of therapeutic vaccination in order to answer key questions relevant to human cancer immunotherapy.
Ahmed, Zeeshan
2010-01-01
In this short paper I briefly discuss 3D war Game based on artificial intelligence concepts called AI WAR. Going in to the details, I present the importance of CAICL language and how this language is used in AI WAR. Moreover I also present a designed and implemented 3D War Cybug for AI WAR using CAICL and discus the implemented strategy to defeat its enemies during the game life.
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...
Coupled Dictionary Learning for the Detail-Enhanced Synthesis of 3-D Facial Expressions.
Liang, Haoran; Liang, Ronghua; Song, Mingli; He, Xiaofei
2016-04-01
The desire to reconstruct 3-D face models with expressions from 2-D face images fosters increasing interest in addressing the problem of face modeling. This task is important and challenging in the field of computer animation. Facial contours and wrinkles are essential to generate a face with a certain expression; however, these details are generally ignored or are not seriously considered in previous studies on face model reconstruction. Thus, we employ coupled radius basis function networks to derive an intermediate 3-D face model from a single 2-D face image. To optimize the 3-D face model further through landmarks, a coupled dictionary that is related to 3-D face models and their corresponding 3-D landmarks is learned from the given training set through local coordinate coding. Another coupled dictionary is then constructed to bridge the 2-D and 3-D landmarks for the transfer of vertices on the face model. As a result, the final 3-D face can be generated with the appropriate expression. In the testing phase, the 2-D input faces are converted into 3-D models that display different expressions. Experimental results indicate that the proposed approach to facial expression synthesis can obtain model details more effectively than previous methods can.
3D seismic surveys for shallow targets
Energy Technology Data Exchange (ETDEWEB)
Lawton, D.C.; Stewart, R.R.; Bertram, M.B. [Calgary Univ., AB (Canada). Dept. of Geoscience, Consortium for Research in Elastic Wave Exploration Seismology
2008-07-01
Although 3D seismic surveys are generally used to map deep hydrocarbon plays, this study demonstrated that they can be useful for characterizing shallow targets, such as oilsands deposits. A high-resolution 3D seismic survey was undertaken to map shallow stratigraphy near Calgary, Alberta. The project demonstrated the efficacy of reflection seismic surveys for shallow targets ranging from 100 to 500 metres. The purpose of the program was to map shallow stratigraphy and structure to depths of up to 500m, and to investigate shallow aquifers in the study area. The results of the survey illustrated the opportunity that 3D seismic surveys provide for mapping shallow reflectors and the acquisition geometry needed to image them. Applications include mapping the distribution of shallow aquifers, delineating shallow coals and investigating oilsands deposits. 2 refs., 5 figs.
PARETO OPTIMAL SOLUTIONS FOR MULTI-OBJECTIVE GENERALIZED ASSIGNMENT PROBLEM
Directory of Open Access Journals (Sweden)
S. Prakash
2012-01-01
Full Text Available
ENGLISH ABSTRACT: The Multi-Objective Generalized Assignment Problem (MGAP with two objectives, where one objective is linear and the other one is non-linear, has been considered, with the constraints that a job is assigned to only one worker – though he may be assigned more than one job, depending upon the time available to him. An algorithm is proposed to find the set of Pareto optimal solutions of the problem, determining assignments of jobs to workers with two objectives without setting priorities for them. The two objectives are to minimise the total cost of the assignment and to reduce the time taken to complete all the jobs.
AFRIKAANSE OPSOMMING: ‘n Multi-doelwit veralgemeende toekenningsprobleem (“multi-objective generalised assignment problem – MGAP” met twee doelwitte, waar die een lineêr en die ander nielineêr is nie, word bestudeer, met die randvoorwaarde dat ‘n taak slegs toegedeel word aan een werker – alhoewel meer as een taak aan hom toegedeel kan word sou die tyd beskikbaar wees. ‘n Algoritme word voorgestel om die stel Pareto-optimale oplossings te vind wat die taaktoedelings aan werkers onderhewig aan die twee doelwitte doen sonder dat prioriteite toegeken word. Die twee doelwitte is om die totale koste van die opdrag te minimiseer en om die tyd te verminder om al die take te voltooi.
3D analysis methods - Study and seminar
International Nuclear Information System (INIS)
Daaviittila, A.
2003-10-01
The first part of the report results from a study that was performed as a Nordic co-operation activity with active participation from Studsvik Scandpower and Westinghouse Atom in Sweden, and VTT in Finland. The purpose of the study was to identify and investigate the effects rising from using the 3D transient com-puter codes in BWR safety analysis, and their influence on the transient analysis methodology. One of the main questions involves the critical power ratio (CPR) calculation methodology. The present way, where the CPR calculation is per-formed with a separate hot channel calculation, can be artificially conservative. In the investigated cases, no dramatic minimum CPR effect coming from the 3D calculation is apparent. Some cases show some decrease in the transient change of minimum CPR with the 3D calculation, which confirms the general thinking that the 1D calculation is conservative. On the other hand, the observed effect on neutron flux behaviour is quite large. In a slower transient the 3D effect might be stronger. The second part of the report is a summary of a related seminar that was held on the 3D analysis methods. The seminar was sponsored by the Reactor Safety part (NKS-R) of the Nordic Nuclear Safety Research Programme (NKS). (au)
Optimization of 3D Field Design
Logan, Nikolas; Zhu, Caoxiang
2017-10-01
Recent progress in 3D tokamak modeling is now leveraged to create a conceptual design of new external 3D field coils for the DIII-D tokamak. Using the IPEC dominant mode as a target spectrum, the Finding Optimized Coils Using Space-curves (FOCUS) code optimizes the currents and 3D geometry of multiple coils to maximize the total set's resonant coupling. The optimized coils are individually distorted in space, creating toroidal ``arrays'' containing a variety of shapes that often wrap around a significant poloidal extent of the machine. The generalized perturbed equilibrium code (GPEC) is used to determine optimally efficient spectra for driving total, core, and edge neoclassical toroidal viscosity (NTV) torque and these too provide targets for the optimization of 3D coil designs. These conceptual designs represent a fundamentally new approach to 3D coil design for tokamaks targeting desired plasma physics phenomena. Optimized coil sets based on plasma response theory will be relevant to designs for future reactors or on any active machine. External coils, in particular, must be optimized for reliable and efficient fusion reactor designs. Work supported by the US Department of Energy under DE-AC02-09CH11466.
3-D discrete shearlet transform and video processing.
Negi, Pooran Singh; Labate, Demetrio
2012-06-01
In this paper, we introduce a digital implementation of the 3-D shearlet transform and illustrate its application to problems of video denoising and enhancement. The shearlet representation is a multiscale pyramid of well-localized waveforms defined at various locations and orientations, which was introduced to overcome the limitations of traditional multiscale systems in dealing with multidimensional data. While the shearlet approach shares the general philosophy of curvelets and surfacelets, it is based on a very different mathematical framework, which is derived from the theory of affine systems and uses shearing matrices rather than rotations. This allows a natural transition from the continuous setting to the digital setting and a more flexible mathematical structure. The 3-D digital shearlet transform algorithm presented in this paper consists in a cascade of a multiscale decomposition and a directional filtering stage. The filters employed in this decomposition are implemented as finite-length filters, and this ensures that the transform is local and numerically efficient. To illustrate its performance, the 3-D discrete shearlet transform is applied to problems of video denoising and enhancement, and compared against other state-of-the-art multiscale techniques, including curvelets and surfacelets.
Immersive 3D geovisualisation in higher education
Philips, Andrea; Walz, Ariane; Bergner, Andreas; Graeff, Thomas; Heistermann, Maik; Kienzler, Sarah; Korup, Oliver; Lipp, Torsten; Schwanghart, Wolfgang; Zeilinger, Gerold
2014-05-01
Through geovisualisation we explore spatial data, we analyse it towards a specific questions, we synthesise results, and we present and communicate them to a specific audience (MacEachren & Kraak 1997). After centuries of paper maps, the means to represent and visualise our physical environment and its abstract qualities have changed dramatically since the 1990s - and accordingly the methods how to use geovisualisation in teaching. Whereas some people might still consider the traditional classroom as ideal setting for teaching and learning geographic relationships and its mapping, we used a 3D CAVE (computer-animated virtual environment) as environment for a problem-oriented learning project called "GEOSimulator". Focussing on this project, we empirically investigated, if such a technological advance like the CAVE make 3D visualisation, including 3D geovisualisation, not only an important tool for businesses (Abulrub et al. 2012) and for the public (Wissen et al. 2008), but also for educational purposes, for which it had hardly been used yet. The 3D CAVE is a three-sided visualisation platform, that allows for immersive and stereoscopic visualisation of observed and simulated spatial data. We examined the benefits of immersive 3D visualisation for geographic research and education and synthesized three fundamental technology-based visual aspects: First, the conception and comprehension of space and location does not need to be generated, but is instantaneously and intuitively present through stereoscopy. Second, optical immersion into virtual reality strengthens this spatial perception which is in particular important for complex 3D geometries. And third, a significant benefit is interactivity, which is enhanced through immersion and allows for multi-discursive and dynamic data exploration and knowledge transfer. Based on our problem-oriented learning project, which concentrates on a case study on flood risk management at the Wilde Weisseritz in Germany, a river
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
3D imaging, 3D printing and 3D virtual planning in endodontics.
Shah, Pratik; Chong, B S
2018-03-01
The adoption and adaptation of recent advances in digital technology, such as three-dimensional (3D) printed objects and haptic simulators, in dentistry have influenced teaching and/or management of cases involving implant, craniofacial, maxillofacial, orthognathic and periodontal treatments. 3D printed models and guides may help operators plan and tackle complicated non-surgical and surgical endodontic treatment and may aid skill acquisition. Haptic simulators may assist in the development of competency in endodontic procedures through the acquisition of psycho-motor skills. This review explores and discusses the potential applications of 3D printed models and guides, and haptic simulators in the teaching and management of endodontic procedures. An understanding of the pertinent technology related to the production of 3D printed objects and the operation of haptic simulators are also presented.
2D to 3D conversion implemented in different hardware
Ramos-Diaz, Eduardo; Gonzalez-Huitron, Victor; Ponomaryov, Volodymyr I.; Hernandez-Fragoso, Araceli
2015-02-01
Conversion of available 2D data for release in 3D content is a hot topic for providers and for success of the 3D applications, in general. It naturally completely relies on virtual view synthesis of a second view given by original 2D video. Disparity map (DM) estimation is a central task in 3D generation but still follows a very difficult problem for rendering novel images precisely. There exist different approaches in DM reconstruction, among them manually and semiautomatic methods that can produce high quality DMs but they demonstrate hard time consuming and are computationally expensive. In this paper, several hardware implementations of designed frameworks for an automatic 3D color video generation based on 2D real video sequence are proposed. The novel framework includes simultaneous processing of stereo pairs using the following blocks: CIE L*a*b* color space conversions, stereo matching via pyramidal scheme, color segmentation by k-means on an a*b* color plane, and adaptive post-filtering, DM estimation using stereo matching between left and right images (or neighboring frames in a video), adaptive post-filtering, and finally, the anaglyph 3D scene generation. Novel technique has been implemented on DSP TMS320DM648, Matlab's Simulink module over a PC with Windows 7, and using graphic card (NVIDIA Quadro K2000) demonstrating that the proposed approach can be applied in real-time processing mode. The time values needed, mean Similarity Structural Index Measure (SSIM) and Bad Matching Pixels (B) values for different hardware implementations (GPU, Single CPU, and DSP) are exposed in this paper.
Reactive flow simulation in complex 3D geometries using the COM3D code
International Nuclear Information System (INIS)
Breitung, W.; Kotchourko, A.; Veser, A.; Scholtyssek, W.
1999-01-01
The COM3D code, under development at the Forschungszentrum Karlsruhe (FZK), is a 3-d CFD code to describe turbulent combustion phenomena in complex geometries. It is intended to be part of the advanced integral code system for containment analysis (INCA) which includes in addition GASFLOW for distribution calculations, V3D for slow combustion and DET3D for detonation analysis. COM3D uses a TVD-solver and optional models for turbulence, chemistry and thermodynamics. The hydrodynamic model considers mass, momentum and energy conservation. Advanced procedures were provided to facilitate grid-development for complex 3-d structures. COM3D was validated on experiments performed on different scales with generally good agreement for important physical quantities. The code was applied to combustion analysis of a large PWR. The initial conditions were obtained from a GASFLOW distribution analysis for a LOOP scenario. Results are presented concerning flame propagation and pressure evolution in the containment which clearly demonstrate the effects of internal structures, their influence on turbulence formation and consequences for local loads. (author)
Origins and development of the Cauchy problem in general relativity
International Nuclear Information System (INIS)
Ringström, Hans
2015-01-01
The seminal work of Yvonne Choquet-Bruhat published in 1952 demonstrates that it is possible to formulate Einstein's equations as an initial value problem. The purpose of this article is to describe the background to and impact of this achievement, as well as the result itself. In some respects, the idea of viewing the field equations of general relativity as a system of evolution equations goes back to Einstein himself; in an argument justifying that gravitational waves propagate at the speed of light, Einstein used a special choice of coordinates to derive a system of wave equations for the linear perturbations on a Minkowski background. Over the following decades, Hilbert, de Donder, Lanczos, Darmois and many others worked to put Einstein's ideas on a more solid footing. In fact, the issue of local uniqueness (giving a rigorous justification for the statement that the speed of propagation of the gravitational field is bounded by that of light) was already settled in the 1930s by the work of Stellmacher. However, the first person to demonstrate both local existence and uniqueness in a setting in which the notion of finite speed of propagation makes sense was Yvonne Choquet-Bruhat. In this sense, her work lays the foundation for the formulation of Einstein's equations as an initial value problem. Following a description of the results of Choquet-Bruhat, we discuss the development of three research topics that have their origin in her work. The first one is local existence. One reason for addressing it is that it is at the heart of the original paper. Moreover, it is still an active and important research field, connected to the problem of characterizing the asymptotic behaviour of solutions that blow up in finite time. As a second topic, we turn to the questions of global uniqueness and strong cosmic censorship. These questions are of fundamental importance to anyone interested in justifying that the Cauchy problem makes sense globally. They are
YouDash3D: exploring stereoscopic 3D gaming for 3D movie theaters
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.
Directory of Open Access Journals (Sweden)
Jürgen eSchmidhuber
2013-06-01
Full Text Available Most of computer science focuses on automatically solving given computational problems. I focus on automatically inventing or discovering problems in a way inspired by the playful behavior of animals and humans, to train a more and more general problem solver from scratch in an unsupervised fashion. Consider the infinite set of all computable descriptions of tasks with possibly computable solutions. The novel algorithmic framework POWERPLAY (2011 continually searches the space of possible pairs of new tasks and modifications of the current problem solver, until it finds a more powerful problem solver that provably solves all previously learned tasks plus the new one, while the unmodified predecessor does not. Wow-effects are achieved by continually making previously learned skills more efficient such that they require less time and space. New skills may (partially re-use previously learned skills. POWERPLAY's search orders candidate pairs of tasks and solver modifications by their conditional computational (time & space complexity, given the stored experience so far. The new task and its corresponding task-solving skill are those first found and validated. The computational costs of validating new tasks need not grow with task repertoire size. POWERPLAY's ongoing search for novelty keeps breaking the generalization abilities of its present solver. This is related to Goedel's sequence of increasingly powerful formal theories based on adding formerly unprovable statements to the axioms without affecting previously provable theorems. The continually increasing repertoire of problem solving procedures can be exploited by a parallel search for solutions to additional externally posed tasks. POWERPLAY may be viewed as a greedy but practical implementation of basic principles of creativity. A first experimental analysis can be found in separate papers [58, 56, 57].
Energy Technology Data Exchange (ETDEWEB)
Imahori, S; Kotera, Y; Nakanishi, T [Japan Energy Development Co. Ltd., Tokyo (Japan)
1997-05-27
Honjo mining area where investigations are conducted is hilly and has a complicated terrain with gas pipes buried in the ground just under the access road disabling the proper positioning of shock-generating large excavators or vibrators. Auger`s shallow hole shooting method is used in this survey to execute blastings at 639 points. In this method using charge depths of 4m, different from the conventional method using deeper charge depths (20-25m), surface waves prevail in the shot records giving rise to a new problem of removing them in the stage of data processing. The 2D filter that is a powerful tool in 2D data processing is not available in a 3D-survey where the tracing intervals are irregular in the shot records. In the effort of this time, a window length as a parameter in the direction of time is specified, and the F-X dip filtering method is employed in which any event that linearly continues beyond a certain number of traces in the said window is eliminated as a linear noise. It is recommended that the weighting function be changed in the direction of space since surface wave velocities are different at different locations. 1 fig., 1 tab.
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...
Modification of 3D milling machine to 3D printer
Taska, Abraham
2014-01-01
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...
DEFF Research Database (Denmark)
Holbek, Simon
, 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...... 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...... hampers the task of real-time processing. In a second study, some of the issue with the 2-D matrix array are solved by introducing a 2-D row-column (RC) addressing array with only 62 + 62 elements. It is investigated both through simulations and via experimental setups in various flow conditions...
Modified and fuzzified general problem solver for 'monkey and banana' problem
International Nuclear Information System (INIS)
Sano, Norihide; Takahashi, Ryoichi.
1994-01-01
Automatic operation is important for the in-service inspection of nuclear power stations of the decommission of retired plants. Master and slave control will be introduced for work-robot control. It is desirable that the slave possess problem-solving capabilities. In this paper we assume that the slave incorporates the general problem solver (GPS) algorithm. In view of having solved the 'monkey and banana' problem, the slave system is regarded as reasonable alternative which incorporates the capability of problem-solving. Basically, the GPS solves a problem by reducing the difference between the initial state and goal state, and hence the performance of GPS depends on selection of the difference to be reduced. The conventional GPS is given the order of importance of the differences in advance. In this study, the GPS was improved by making use of the rules which determine the order. When several choices are available for the given difference, a fuzzified decision to determine the necessary action is made, as demonstrated in this paper. (author)
3D Deep Learning Angiography (3D-DLA) from C-arm Conebeam CT.
Montoya, J C; Li, Y; Strother, C; Chen, G-H
2018-05-01
Deep learning is a branch of artificial intelligence that has demonstrated unprecedented performance in many medical imaging applications. Our purpose was to develop a deep learning angiography method to generate 3D cerebral angiograms from a single contrast-enhanced C-arm conebeam CT acquisition in order to reduce image artifacts and radiation dose. A set of 105 3D rotational angiography examinations were randomly selected from an internal data base. All were acquired using a clinical system in conjunction with a standard injection protocol. More than 150 million labeled voxels from 35 subjects were used for training. A deep convolutional neural network was trained to classify each image voxel into 3 tissue types (vasculature, bone, and soft tissue). The trained deep learning angiography model was then applied for tissue classification into a validation cohort of 8 subjects and a final testing cohort of the remaining 62 subjects. The final vasculature tissue class was used to generate the 3D deep learning angiography images. To quantify the generalization error of the trained model, we calculated the accuracy, sensitivity, precision, and Dice similarity coefficients for vasculature classification in relevant anatomy. The 3D deep learning angiography and clinical 3D rotational angiography images were subjected to a qualitative assessment for the presence of intersweep motion artifacts. Vasculature classification accuracy and 95% CI in the testing dataset were 98.7% (98.3%-99.1%). No residual signal from osseous structures was observed for any 3D deep learning angiography testing cases except for small regions in the otic capsule and nasal cavity compared with 37% (23/62) of the 3D rotational angiographies. Deep learning angiography accurately recreated the vascular anatomy of the 3D rotational angiography reconstructions without a mask. Deep learning angiography reduced misregistration artifacts induced by intersweep motion, and it reduced radiation exposure
3D Printed Bionic Nanodevices.
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
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
A Generalized Mathematical Model for the Fracture Problem of the Suspended Highway
Directory of Open Access Journals (Sweden)
Zhao Ying
2017-01-01
Full Text Available In order to answer dangling fracture problems of highway, the suspended pavement equivalent for non - suspended pavement, through the special boundary conditions has been suspended highway stress field of expression, in accordance with the 3D fracture model of crack formation, and establish a vacant, a general mathematics model for fracture problems of highway and analysis in highway suspended segment weight and vehicle load limit of highway capacity of Pu For overturning road inPu is less than the force of carrying more than compared to the work and fruit Bridge Hydropower Station Road engineering examples to verify suspended highway should force field expressions for the correctness and applicability. The results show that: when the hanging ratio R 0. 243177 limits of Pu design axle load 100kN. When the vertical crack in the vacant in the direction of length greater than 0. 1, the ultimate bearing capacity is less than the design axle load 100kN; when the hanging ratio R is less than 0. 5, the road to local fracture, the ultimate bearing capacity of suspended stress field expressions in solution; when the hanging ratio is greater than or equal to 0. 5, the road does not reach the limit bearing capacity of the whole body; torque shear surface of the effect is far less than the bending moments on shear planes.
An efficient iterative method for the generalized Stokes problem
Energy Technology Data Exchange (ETDEWEB)
Sameh, A. [Univ. of Minnesota, Twin Cities, MN (United States); Sarin, V. [Univ. of Illinois, Urbana, IL (United States)
1996-12-31
This paper presents an efficient iterative scheme for the generalized Stokes problem, which arises frequently in the simulation of time-dependent Navier-Stokes equations for incompressible fluid flow. The general form of the linear system is where A = {alpha}M + vT is an n x n symmetric positive definite matrix, in which M is the mass matrix, T is the discrete Laplace operator, {alpha} and {nu} are positive constants proportional to the inverses of the time-step {Delta}t and the Reynolds number Re respectively, and B is the discrete gradient operator of size n x k (k < n). Even though the matrix A is symmetric and positive definite, the system is indefinite due to the incompressibility constraint (B{sup T}u = 0). This causes difficulties both for iterative methods and commonly used preconditioners. Moreover, depending on the ratio {alpha}/{nu}, A behaves like the mass matrix M at one extreme and the Laplace operator T at the other, thus complicating the issue of preconditioning.
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)
A point-centered diffusion differencing for unstructured meshes in 3-D
International Nuclear Information System (INIS)
Palmer, T.S.
1994-01-01
We describe a point-centered diffusion discretization for 3-D unstructured meshes of polyhedra. The method has several attractive qualities, including second-order accuracy and preservation of linear solutions. A potential drawback to the scheme is that the diffusion matrix is asymmetric, in general. Results of numerical test problems illustrate the behavior of the scheme
Computation of 3D form factors in complex environments
International Nuclear Information System (INIS)
Coulon, N.
1989-01-01
The calculation of radiant interchange among opaque surfaces in a complex environment poses the general problem of determining the visible and hidden parts of the environment. In many thermal engineering applications, surfaces are separated by radiatively non-participating media and may be idealized as diffuse emitters and reflectors. Consenquently the net radiant energy fluxes are intimately related to purely geometrical quantities called form factors, that take into account hidden parts: the problem is reduced to the form factor evaluation. This paper presents the method developed for the computation of 3D form factors in the finite-element module of the system TRIO, which is a general computer code for thermal and fluid flow analysis. The method is derived from an algorithm devised for synthetic image generation. A comparison is performed with the standard contour integration method also implemented and suited to convex geometries. Several illustrative examples of finite-element thermal calculations in radiating enclosures are given
Planetary Torque in 3D Isentropic Disks
International Nuclear Information System (INIS)
Fung, Jeffrey; Masset, Frédéric; Velasco, David; Lega, Elena
2017-01-01
Planetary migration is inherently a three-dimensional (3D) problem, because Earth-size planetary cores are deeply embedded in protoplanetary disks. Simulations of these 3D disks remain challenging due to the steep resolution requirements. Using two different hydrodynamics codes, FARGO3D and PEnGUIn, we simulate disk–planet interaction for a one to five Earth-mass planet embedded in an isentropic disk. We measure the torque on the planet and ensure that the measurements are converged both in resolution and between the two codes. We find that the torque is independent of the smoothing length of the planet’s potential ( r s ), and that it has a weak dependence on the adiabatic index of the gaseous disk ( γ ). The torque values correspond to an inward migration rate qualitatively similar to previous linear calculations. We perform additional simulations with explicit radiative transfer using FARGOCA, and again find agreement between 3D simulations and existing torque formulae. We also present the flow pattern around the planets that show active flow is present within the planet’s Hill sphere, and meridional vortices are shed downstream. The vertical flow speed near the planet is faster for a smaller r s or γ , up to supersonic speeds for the smallest r s and γ in our study.
Planetary Torque in 3D Isentropic Disks
Energy Technology Data Exchange (ETDEWEB)
Fung, Jeffrey [Department of Astronomy, University of California at Berkeley, Campbell Hall, Berkeley, CA 94720-3411 (United States); Masset, Frédéric; Velasco, David [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Av. Universidad s/n, 62210 Cuernavaca, Mor. (Mexico); Lega, Elena, E-mail: jeffrey.fung@berkeley.edu [Université de la Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange UMR 7293, Nice (France)
2017-03-01
Planetary migration is inherently a three-dimensional (3D) problem, because Earth-size planetary cores are deeply embedded in protoplanetary disks. Simulations of these 3D disks remain challenging due to the steep resolution requirements. Using two different hydrodynamics codes, FARGO3D and PEnGUIn, we simulate disk–planet interaction for a one to five Earth-mass planet embedded in an isentropic disk. We measure the torque on the planet and ensure that the measurements are converged both in resolution and between the two codes. We find that the torque is independent of the smoothing length of the planet’s potential ( r {sub s}), and that it has a weak dependence on the adiabatic index of the gaseous disk ( γ ). The torque values correspond to an inward migration rate qualitatively similar to previous linear calculations. We perform additional simulations with explicit radiative transfer using FARGOCA, and again find agreement between 3D simulations and existing torque formulae. We also present the flow pattern around the planets that show active flow is present within the planet’s Hill sphere, and meridional vortices are shed downstream. The vertical flow speed near the planet is faster for a smaller r {sub s} or γ , up to supersonic speeds for the smallest r {sub s} and γ in our study.
DEFF Research Database (Denmark)
Pedersen, Pernille Klarskov; Strikwerda, Andrew; Jepsen, Peter Uhd
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...
3D Printing: Exploring Capabilities
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…
Modified and fuzzified general problem solver for 'monkey and banana' problem, 2
International Nuclear Information System (INIS)
Sano, Norihide; Takahashi, Ryoichi.
1991-01-01
The automatic operation is important for the in-service inspection of the operating nuclear power station or the decommission of retired plants. The master and slave control will be introduced for work-robot control. It is desirable that the slave involves the capability of problem solving. This paper assumed that the slave involved the general problem solver algorithm. In view of having solved the puzzle of the 'monkey and banana', the slave system is regarded as the reasonable alternative which incorporates the capability of problem solving. Basically, the GPS solves a problem by reducing the difference between an initial state and a goal state, and hence the performance of GPS depends on selecting the difference to be reduced. The usual GPS is given in advance the ordering which indicates the importance of the differences. In this paper, the GPS was improved by making use of the rules which decide the order. When several choices are found on the given difference, the fuzzified decision to determine the action is demonstrated in this paper. (author)
Modified and fuzzified general problem solver for the 'monkey and banana' problem, 1
International Nuclear Information System (INIS)
Sano, Norihide; Takahashi, Ryoichi.
1991-01-01
The master-and-slave control system should be extensively implemented for the in-service inspection of operating nuclear power stations or the decommission of retired plants. The performance of this system depends on the intelligent slave. In this paper the degree of intelligence is approximated by the given amount of prior knowledge or suggestions. This paper aims at improving the general problem solver (GPS) by incorporating the learning process in order to solve the puzzle of the 'monkey and banana'. The monkey in this puzzle may be a reasonable alternative to represent the intelligent slave. Also, this paper deals with fuzzified problem solving since the master's command is not always crisp to the slave. (author)
AxiSEM3D: broadband seismic wavefields in 3-D aspherical Earth models
Leng, K.; Nissen-Meyer, T.; Zad, K. H.; van Driel, M.; Al-Attar, D.
2017-12-01
Seismology is the primary tool for data-informed inference of Earth structure and dynamics. Simulating seismic wave propagation at a global scale is fundamental to seismology, but remains as one of most challenging problems in scientific computing, because of both the multiscale nature of Earth's interior and the observable frequency band of seismic data. We present a novel numerical method to simulate global seismic wave propagation in realistic 3-D Earth models. Our method, named AxiSEM3D, is a hybrid of spectral element method and pseudospectral method. It reduces the azimuthal dimension of wavefields by means of a global Fourier series parameterization, of which the number of terms can be locally adapted to the inherent azimuthal smoothness of the wavefields. AxiSEM3D allows not only for material heterogeneities, such as velocity, density, anisotropy and attenuation, but also for finite undulations on radial discontinuities, both solid-solid and solid-fluid, and thereby a variety of aspherical Earth features such as ellipticity, topography, variable crustal thickness, and core-mantle boundary topography. Such interface undulations are equivalently interpreted as material perturbations of the contiguous media, based on the "particle relabelling transformation". Efficiency comparisons show that AxiSEM3D can be 1 to 3 orders of magnitude faster than conventional 3-D methods, with the speedup increasing with simulation frequency and decreasing with model complexity, but for all realistic structures the speedup remains at least one order of magnitude. The observable frequency range of global seismic data (up to 1 Hz) has been covered for wavefield modelling upon a 3-D Earth model with reasonable computing resources. We show an application of surface wave modelling within a state-of-the-art global crustal model (Crust1.0), with the synthetics compared to real data. The high-performance C++ code is released at github.com/AxiSEM3D/AxiSEM3D.
3D Face modeling using the multi-deformable method.
Hwang, Jinkyu; Yu, Sunjin; Kim, Joongrock; Lee, Sangyoun
2012-09-25
In this paper, we focus on the problem of the accuracy performance of 3D face modeling techniques using corresponding features in multiple views, which is quite sensitive to feature extraction errors. To solve the problem, we adopt a statistical model-based 3D face modeling approach in a mirror system consisting of two mirrors and a camera. The overall procedure of our 3D facial modeling method has two primary steps: 3D facial shape estimation using a multiple 3D face deformable model and texture mapping using seamless cloning that is a type of gradient-domain blending. To evaluate our method's performance, we generate 3D faces of 30 individuals and then carry out two tests: accuracy test and robustness test. Our method shows not only highly accurate 3D face shape results when compared with the ground truth, but also robustness to feature extraction errors. Moreover, 3D face rendering results intuitively show that our method is more robust to feature extraction errors than other 3D face modeling methods. An additional contribution of our method is that a wide range of face textures can be acquired by the mirror system. By using this texture map, we generate realistic 3D face for individuals at the end of the paper.
3D Data Acquisition Platform for Human Activity Understanding
2016-03-02
SECURITY CLASSIFICATION OF: In this project, we incorporated motion capture devices, 3D vision sensors, and EMG sensors to cross validate...multimodality data acquisition, and address fundamental research problems of representation and invariant description of 3D data, human motion modeling and...applications of human activity analysis, and computational optimization of large-scale 3D data. The support for the acquisition of such research
On maximal massive 3D supergravity
Bergshoeff , Eric A; Hohm , Olaf; Rosseel , Jan; Townsend , Paul K
2010-01-01
ABSTRACT We construct, at the linearized level, the three-dimensional (3D) N = 4 supersymmetric " general massive supergravity " and the maximally supersymmetric N = 8 " new massive supergravity ". We also construct the maximally supersymmetric linearized N = 7 topologically massive supergravity, although we expect N = 6 to be maximal at the non-linear level. (Bergshoeff, Eric A) (Hohm, Olaf) (Rosseel, Jan) P.K.Townsend@da...
3D histomorphometric quantification from 3D computed tomography
International Nuclear Information System (INIS)
Oliveira, L.F. de; Lopes, R.T.
2004-01-01
The histomorphometric analysis is based on stereologic concepts and was originally applied to biologic samples. This technique has been used to evaluate different complex structures such as ceramic filters, net structures and cancellous objects that are objects with inner connected structures. The measured histomorphometric parameters of structure are: sample volume to total reconstructed volume (BV/TV), sample surface to sample volume (BS/BV), connection thickness (Tb Th ), connection number (Tb N ) and connection separation (Tb Sp ). The anisotropy was evaluated as well. These parameters constitute the base of histomorphometric analysis. The quantification is realized over cross-sections recovered by cone beam reconstruction, where a real-time microfocus radiographic system is used as tomographic system. The three-dimensional (3D) histomorphometry, obtained from tomography, corresponds to an evolution of conventional method that is based on 2D analysis. It is more coherent with morphologic and topologic context of the sample. This work shows result from 3D histomorphometric quantification to characterize objects examined by 3D computer tomography. The results, which characterizes the internal structures of ceramic foams with different porous density, are compared to results from conventional methods
Some problems in generalized electromagnetic thermoelasticity and wave propagation
International Nuclear Information System (INIS)
Mohamed, S.E.S.
2012-01-01
The first chapter contains a review of the classical theory of elasticity, the theory of thermodynamics, the theory of uncoupled thermoelasticity, the coupled theory of thermoelasticity, the generalized theory of thermoelasticity with one relaxation time, electromagneto thermoelasticity and an introduction to wave propagation in elastic media. Chapter two is devoted to the study of wave propagation for a problem of an infinitely long solid conducting circular cylinder whose lateral surface is traction free and subjected to a known surrounding temperatures in the presence of a uniform magnetic field in the direction of the axis of the cylinder. Laplace transform techniques are used to derive the solution in the Laplace transform domain. The inversion process is carried out using asymptotic expansions valid for short tines. Numerical results are computed for the temperature, displacement, stress,induced magnetic field and induced electric field distributions. The chapter contains also a study of the wave propagation in the elastic medium. In chapter three, we consider the two-dimensional problem of an infinitely long conducting solid cylinder. The lateral surface of the cylinder is taken to be traction free and is subjected to a known temperature distribution independent of z in the presence of a uniform magnetic field in the direction of the axis of the cylinder. Laplace transform techniques are used. The inversion process is carried out using a numerical method based on Fourier series expansions. Numerical results are computed and represented graphically. The chapter contains also a study of the wave propagation in the elastic medium. In chapter four, we consider a two-dimensional problem for an infinity long cylinder. The lateral surface of the cylinder is taken to be traction free and is subjected to a known temperature distribution independent of φ in the presence of a uniform electric field in the direction of the binomial of the cylinder axis. Laplace and
3-D Discrete Analytical Ridgelet Transform
Helbert , David; Carré , Philippe; Andrès , Éric
2006-01-01
International audience; In this paper, we propose an implementation of the 3-D Ridgelet transform: the 3-D discrete analytical Ridgelet transform (3-D DART). This transform uses the Fourier strategy for the computation of the associated 3-D discrete Radon transform. The innovative step is the definition of a discrete 3-D transform with the discrete analytical geometry theory by the construction of 3-D discrete analytical lines in the Fourier domain. We propose two types of 3-D discrete lines:...
Study of a 3D dosimetry system response: ARCCHECK®
Energy Technology Data Exchange (ETDEWEB)
Mazer, Amanda C.; Yoriyaz, Hélio, E-mail: amandamazer18@gmail.com, E-mail: hyoriyaz@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Nakandakari, Marcos V.N., E-mail: marcos.sake@gmail.com [Beneficência Portuguesa de São Paulo, SP (Brazil)
2017-07-01
Ionizing radiation therapies have improved over the years, becoming more specific for each patient. Thereby as the treatment planning system (TPS) complexities increases, the quality assurance (QA) methods have to be in a constant evolution. One of the techniques that demand great complexity is the Volumetric Modulated Arc Therapy (VMAT). One possible way to VMAT commissioning is using 3D dosimetry systems and recently a new 3D dosimetry system called ArcCheck had been developed and commercialized mainly for VMAT quality assurance. It is water-equivalent and composed by an array of 1386 diodes arranged in a spiral pattern. Since simulation methods, like Monte Carlo method, ensure highly accurate results, MCNP (A General Monte Carlo N-Particle Transport Code System) is totally reliable for problems that involve radiation transport. This work presents a preliminary study of the 3D dosimetry system ArcCheck by developing two computational models in MCNP6. In addition, experimental measures were acquired using the ArcCheck in a Linear Accelerator and then these values were compared with the results obtained by simulations of both models. The comparisons showed good reproducibility. (author)
Accurate 3D Mapping Algorithm for Flexible Antennas
Directory of Open Access Journals (Sweden)
Saed Asaly
2018-01-01
Full Text Available This work addresses the problem of performing an accurate 3D mapping of a flexible antenna surface. Consider a high-gain satellite flexible antenna; even a submillimeter change in the antenna surface may lead to a considerable loss in the antenna gain. Using a robotic subreflector, such changes can be compensated for. Yet, in order to perform such tuning, an accurate 3D mapping of the main antenna is required. This paper presents a general method for performing an accurate 3D mapping of marked surfaces such as satellite dish antennas. Motivated by the novel technology for nanosatellites with flexible high-gain antennas, we propose a new accurate mapping framework which requires a small-sized monocamera and known patterns on the antenna surface. The experimental result shows that the presented mapping method can detect changes up to 0.1-millimeter accuracy, while the camera is located 1 meter away from the dish, allowing an RF antenna optimization for Ka and Ku frequencies. Such optimization process can improve the gain of the flexible antennas and allow an adaptive beam shaping. The presented method is currently being implemented on a nanosatellite which is scheduled to be launched at the end of 2018.
Limited Data Problems for the Generalized Radon Transform in Rn
DEFF Research Database (Denmark)
Frikel, Jürgen; Quinto, Eric Todd
2016-01-01
We consider the generalized Radon transform (defined in terms of smooth weight functions) on hyperplanes in Rn. We analyze general filtered backprojection type reconstruction methods for limited data with filters given by general pseudodifferential operators. We provide microlocal characterizations...
3D space analysis of dental models
Chuah, Joon H.; Ong, Sim Heng; Kondo, Toshiaki; Foong, Kelvin W. C.; Yong, Than F.
2001-05-01
Space analysis is an important procedure by orthodontists to determine the amount of space available and required for teeth alignment during treatment planning. Traditional manual methods of space analysis are tedious and often inaccurate. Computer-based space analysis methods that work on 2D images have been reported. However, as the space problems in the dental arch exist in all three planes of space, a full 3D analysis of the problems is necessary. This paper describes a visualization and measurement system that analyses 3D images of dental plaster models. Algorithms were developed to determine dental arches. The system is able to record the depths of the Curve of Spee, and quantify space liabilities arising from a non-planar Curve of Spee, malalignment and overjet. Furthermore, the difference between total arch space available and the space required to arrange the teeth in ideal occlusion can be accurately computed. The system for 3D space analysis of the dental arch is an accurate, comprehensive, rapid and repeatable method of space analysis to facilitate proper orthodontic diagnosis and treatment planning.
Abstract generalized vector quasi-equilibrium problems in noncompact Hadamard manifolds
Directory of Open Access Journals (Sweden)
Haishu Lu
2017-05-01
Full Text Available Abstract This paper deals with the abstract generalized vector quasi-equilibrium problem in noncompact Hadamard manifolds. We prove the existence of solutions to the abstract generalized vector quasi-equilibrium problem under suitable conditions and provide applications to an abstract vector quasi-equilibrium problem, a generalized scalar equilibrium problem, a scalar equilibrium problem, and a perturbed saddle point problem. Finally, as an application of the existence of solutions to the generalized scalar equilibrium problem, we obtain a weakly mixed variational inequality and two mixed variational inequalities. The results presented in this paper unify and generalize many known results in the literature.
3D integrated superconducting qubits
Rosenberg, D.; Kim, D.; Das, R.; Yost, D.; Gustavsson, S.; Hover, D.; Krantz, P.; Melville, A.; Racz, L.; Samach, G. O.; Weber, S. J.; Yan, F.; Yoder, J. L.; Kerman, A. J.; Oliver, W. D.
2017-10-01
As the field of quantum computing advances from the few-qubit stage to larger-scale processors, qubit addressability and extensibility will necessitate the use of 3D integration and packaging. While 3D integration is well-developed for commercial electronics, relatively little work has been performed to determine its compatibility with high-coherence solid-state qubits. Of particular concern, qubit coherence times can be suppressed by the requisite processing steps and close proximity of another chip. In this work, we use a flip-chip process to bond a chip with superconducting flux qubits to another chip containing structures for qubit readout and control. We demonstrate that high qubit coherence (T1, T2,echo > 20 μs) is maintained in a flip-chip geometry in the presence of galvanic, capacitive, and inductive coupling between the chips.
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.
Directory of Open Access Journals (Sweden)
Demyanenko Olga
2018-01-01
Full Text Available The paper is aimed at developing scientifically proven compositions of mortars for 3D printing modified by a peat-based admixture with improved operational characteristics. The paper outlines the results of experimental research on hardened cement paste and concrete mixture with the use of modifying admixture MT-600 (thermally modified peat. It is found that strength of hardened cement paste increases at early age when using finely dispersed admixtures, which is the key factor for formation of construction and technical specifications of concrete for 3D printing technologies. The composition of new formations of hardened cement paste modified by MT-600 admixture were obtained, which enabled to suggest the possibility of their physico-chemical interaction while hardening.
Automated 3-D Radiation Mapping
International Nuclear Information System (INIS)
Tarpinian, J. E.
1991-01-01
This work describes an automated radiation detection and imaging system which combines several state-of-the-art technologies to produce a portable but very powerful visualization tool for planning work in radiation environments. The system combines a radiation detection system, a computerized radiation imaging program, and computerized 3-D modeling to automatically locate and measurements are automatically collected and imaging techniques are used to produce colored, 'isodose' images of the measured radiation fields. The isodose lines from the images are then superimposed over the 3-D model of the area. The final display shows the various components in a room and their associated radiation fields. The use of an automated radiation detection system increases the quality of radiation survey obtained measurements. The additional use of a three-dimensional display allows easier visualization of the area and associated radiological conditions than two-dimensional sketches
Forensic 3D Scene Reconstruction
International Nuclear Information System (INIS)
LITTLE, CHARLES Q.; PETERS, RALPH R.; RIGDON, J. BRIAN; SMALL, DANIEL E.
1999-01-01
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
Java 3D Interactive Visualization for Astrophysics
Chae, K.; Edirisinghe, D.; Lingerfelt, E. J.; Guidry, M. W.
2003-05-01
We are developing a series of interactive 3D visualization tools that employ the Java 3D API. We have applied this approach initially to a simple 3-dimensional galaxy collision model (restricted 3-body approximation), with quite satisfactory results. Running either as an applet under Web browser control, or as a Java standalone application, this program permits real-time zooming, panning, and 3-dimensional rotation of the galaxy collision simulation under user mouse and keyboard control. We shall also discuss applications of this technology to 3-dimensional visualization for other problems of astrophysical interest such as neutron star mergers and the time evolution of element/energy production networks in X-ray bursts. *Managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
3D neutron transport modelization
International Nuclear Information System (INIS)
Warin, X.
1996-12-01
Some nodal methods to solve the transport equation in 3D are presented. Two nodal methods presented at an OCDE congress are described: a first one is a low degree one called RTN0; a second one is a high degree one called BDM1. The two methods can be made faster with a totally consistent DSA. Some results of parallelization show that: 98% of the time is spent in sweeps; transport sweeps are easily parallelized. (K.A.)
Directory of Open Access Journals (Sweden)
Muhammad Zulkifl Hasan
2017-08-01
Full Text Available Solid free fabrication SFF are produced to enhance the printing instrument utilizing distinctive strategies like Piezo spout control multi-spout injet printers or STL arrange utilizing cutting information. The procedure is utilized to diminish the cost and enhance the speed of printing. A few techniques take long at last because of extra process like dry the printing. This study will concentrate on SFFS utilizing UV gum for 3D printing.
3D neutron transport modelization
Energy Technology Data Exchange (ETDEWEB)
Warin, X.
1996-12-01
Some nodal methods to solve the transport equation in 3D are presented. Two nodal methods presented at an OCDE congress are described: a first one is a low degree one called RTN0; a second one is a high degree one called BDM1. The two methods can be made faster with a totally consistent DSA. Some results of parallelization show that: 98% of the time is spent in sweeps; transport sweeps are easily parallelized. (K.A.). 10 refs.
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...... 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...
[Real time 3D echocardiography
Bauer, F.; Shiota, T.; Thomas, J. D.
2001-01-01
Three-dimensional representation of the heart is an old concern. Usually, 3D reconstruction of the cardiac mass is made by successive acquisition of 2D sections, the spatial localisation and orientation of which require complex guiding systems. More recently, the concept of volumetric acquisition has been introduced. A matricial emitter-receiver probe complex with parallel data processing provides instantaneous of a pyramidal 64 degrees x 64 degrees volume. The image is restituted in real time and is composed of 3 planes (planes B and C) which can be displaced in all spatial directions at any time during acquisition. The flexibility of this system of acquisition allows volume and mass measurement with greater accuracy and reproducibility, limiting inter-observer variability. Free navigation of the planes of investigation allows reconstruction for qualitative and quantitative analysis of valvular heart disease and other pathologies. Although real time 3D echocardiography is ready for clinical usage, some improvements are still necessary to improve its conviviality. Then real time 3D echocardiography could be the essential tool for understanding, diagnosis and management of patients.
Xie, Edwar; Deppe, Frank; Renger, Michael; Repp, Daniel; Eder, Peter; Fischer, Michael; Goetz, Jan; Pogorzalek, Stefan; Fedorov, Kirill G.; Marx, Achim; Gross, Rudolf
2018-05-01
Superconducting 3D microwave cavities offer state-of-the-art coherence times and a well-controlled environment for superconducting qubits. In order to realize at the same time fast readout and long-lived quantum information storage, one can couple the qubit to both a low-quality readout and a high-quality storage cavity. However, such systems are bulky compared to their less coherent 2D counterparts. A more compact and scalable approach is achieved by making use of the multimode structure of a 3D cavity. In our work, we investigate such a device where a transmon qubit is capacitively coupled to two modes of a single 3D cavity. External coupling is engineered so that the memory mode has an about 100 times larger quality factor than the readout mode. Using an all-microwave second-order protocol, we realize a lifetime enhancement of the stored state over the qubit lifetime by a factor of 6 with a fidelity of approximately 80% determined via quantum process tomography. We also find that this enhancement is not limited by fundamental constraints.
Binary pattern analysis for 3D facial action unit detection
Sandbach, Georgia; Zafeiriou, Stefanos; Pantic, Maja
2012-01-01
In this paper we propose new binary pattern features for use in the problem of 3D facial action unit (AU) detection. Two representations of 3D facial geometries are employed, the depth map and the Azimuthal Projection Distance Image (APDI). To these the traditional Local Binary Pattern is applied,
A General Theory of Markovian Time Inconsistent Stochastic Control Problems
DEFF Research Database (Denmark)
Björk, Tomas; Murgochi, Agatha
We develop a theory for stochastic control problems which, in various ways, are time inconsistent in the sense that they do not admit a Bellman optimality principle. We attach these problems by viewing them within a game theoretic framework, and we look for Nash subgame perfect equilibrium points...... examples of time inconsistency in the literature are easily seen to be special cases of the present theory. We also prove that for every time inconsistent problem, there exists an associated time consistent problem such that the optimal control and the optimal value function for the consistent problem...
3D - Acquisition systems - test in Chooz B nuclear plant
International Nuclear Information System (INIS)
Brillault, B.; Thibault, G.
1992-06-01
EDF needs 3D-acquisition systems to get the precise geometry of critical nuclear spaces in order to prepare computer simulations of operations in these areas. The simulations must lead to an increase of the efficiency of the operation. The acquisition of the 3-D geometry can be done using 3D-acquisition systems. To answer the needs of the Construction Division, four different systems are compared by the Research Division in Chooz B nuclear plant in order to determine the right solution for each 3D-acquisition problem
International Nuclear Information System (INIS)
Parzefall, Ulrich; Bates, Richard; Boscardin, Maurizio; Dalla Betta, Gian-Franco; Eckert, Simon; Eklund, Lars; Fleta, Celeste; Jakobs, Karl; Kuehn, Susanne; Lozano, Manuel; Pahn, Gregor; Parkes, Chris; Pellegrini, Giulio; Pennicard, David; Piemonte, Claudio; Ronchin, Sabina; Szumlak, Tomasz; Zoboli, Andrea; Zorzi, Nicola
2009-01-01
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 15 N eq /cm 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 15 N eq /cm 2 . The tests were performed with three systems: a highly focused IR-laser with 5μm spot size to make position-resolved scans of the charge collection efficiency, an Sr 90 β-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 the results obtained with 3D-STC-modules.
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
Kent, G. M.; Harding, A. J.; Babcock, J. M.; Orcutt, J. A.; Bazin, S.; Singh, S.; Detrick, R. S.; Canales, J. P.; Carbotte, S. M.; Diebold, J.
2002-12-01
Multichannel seismic (MCS) images of crustal magma chambers are ideal targets for advanced visualization techniques. In the mid-ocean ridge environment, reflections originating at the melt-lens are well separated from other reflection boundaries, such as the seafloor, layer 2A and Moho, which enables the effective use of transparency filters. 3-D visualization of seismic reflectivity falls into two broad categories: volume and surface rendering. Volumetric-based visualization is an extremely powerful approach for the rapid exploration of very dense 3-D datasets. These 3-D datasets are divided into volume elements or voxels, which are individually color coded depending on the assigned datum value; the user can define an opacity filter to reject plotting certain voxels. This transparency allows the user to peer into the data volume, enabling an easy identification of patterns or relationships that might have geologic merit. Multiple image volumes can be co-registered to look at correlations between two different data types (e.g., amplitude variation with offsets studies), in a manner analogous to draping attributes onto a surface. In contrast, surface visualization of seismic reflectivity usually involves producing "fence" diagrams of 2-D seismic profiles that are complemented with seafloor topography, along with point class data, draped lines and vectors (e.g. fault scarps, earthquake locations and plate-motions). The overlying seafloor can be made partially transparent or see-through, enabling 3-D correlations between seafloor structure and seismic reflectivity. Exploration of 3-D datasets requires additional thought when constructing and manipulating these complex objects. As numbers of visual objects grow in a particular scene, there is a tendency to mask overlapping objects; this clutter can be managed through the effective use of total or partial transparency (i.e., alpha-channel). In this way, the co-variation between different datasets can be investigated
Imaging chemical reactions - 3D velocity mapping
Chichinin, A. I.; Gericke, K.-H.; Kauczok, S.; Maul, C.
Visualising a collision between an atom or a molecule or a photodissociation (half-collision) of a molecule on a single particle and single quantum level is like watching the collision of billiard balls on a pool table: Molecular beams or monoenergetic photodissociation products provide the colliding reactants at controlled velocity before the reaction products velocity is imaged directly with an elaborate camera system, where one should keep in mind that velocity is, in general, a three-dimensional (3D) vectorial property which combines scattering angles and speed. If the processes under study have no cylindrical symmetry, then only this 3D product velocity vector contains the full information of the elementary process under study.
Deep imitation learning for 3D navigation tasks.
Hussein, Ahmed; Elyan, Eyad; Gaber, Mohamed Medhat; Jayne, Chrisina
2018-01-01
Deep learning techniques have shown success in learning from raw high-dimensional data in various applications. While deep reinforcement learning is recently gaining popularity as a method to train intelligent agents, utilizing deep learning in imitation learning has been scarcely explored. Imitation learning can be an efficient method to teach intelligent agents by providing a set of demonstrations to learn from. However, generalizing to situations that are not represented in the demonstrations can be challenging, especially in 3D environments. In this paper, we propose a deep imitation learning method to learn navigation tasks from demonstrations in a 3D environment. The supervised policy is refined using active learning in order to generalize to unseen situations. This approach is compared to two popular deep reinforcement learning techniques: deep-Q-networks and Asynchronous actor-critic (A3C). The proposed method as well as the reinforcement learning methods employ deep convolutional neural networks and learn directly from raw visual input. Methods for combining learning from demonstrations and experience are also investigated. This combination aims to join the generalization ability of learning by experience with the efficiency of learning by imitation. The proposed methods are evaluated on 4 navigation tasks in a 3D simulated environment. Navigation tasks are a typical problem that is relevant to many real applications. They pose the challenge of requiring demonstrations of long trajectories to reach the target and only providing delayed rewards (usually terminal) to the agent. The experiments show that the proposed method can successfully learn navigation tasks from raw visual input while learning from experience methods fail to learn an effective policy. Moreover, it is shown that active learning can significantly improve the performance of the initially learned policy using a small number of active samples.
SOCIAL NETWORK OPTIMIZATION A NEW METHAHEURISTIC FOR GENERAL OPTIMIZATION PROBLEMS
Directory of Open Access Journals (Sweden)
Hassan Sherafat
2017-12-01
Full Text Available In the recent years metaheuristics were studied and developed as powerful technics for hard optimization problems. Some of well-known technics in this field are: Genetic Algorithms, Tabu Search, Simulated Annealing, Ant Colony Optimization, and Swarm Intelligence, which are applied successfully to many complex optimization problems. In this paper, we introduce a new metaheuristic for solving such problems based on social networks concept, named as Social Network Optimization – SNO. We show that a wide range of np-hard optimization problems may be solved by SNO.
Institutional Problems and Solutions of General Education in Chinese Universities
Meng, Weiqing; Huang, Wei
2018-01-01
Embedding general education in the Chinese university education system is a considerably complex systemic project, and a lack of institutional arrangements beneficial to general education has always been a key barrier in implementation. Currently, the main institutional restricting factors for university general education include substantial…
Directory of Open Access Journals (Sweden)
Mohammed Zia
2018-03-01
Full Text Available The Equality-Generalized Travelling Salesman Problem (E-GTSP, which is an extension of the Travelling Salesman Problem (TSP, is stated as follows: given groups of points within a city, like banks, supermarkets, etc., find a minimum cost Hamiltonian cycle that visits each group exactly once. It can model many real-life combinatorial optimization scenarios more efficiently than TSP. This study presents five spatially driven search-algorithms for possible transformation of E-GTSP to TSP by considering the spatial spread of points in a given urban city. Presented algorithms are tested over 15 different cities, classified by their street-network’s fractal-dimension. Obtained results denote that the R-Search algorithm, which selects the points from each group based on their radial separation with respect to the start–end point, is the best search criterion for any E-GTSP to TSP conversion modelled for a city street network. An 8.8% length error has been reported for this algorithm.
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.
Interactive 3D Mars Visualization
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.
3D widefield light microscope image reconstruction without dyes
Larkin, S.; Larson, J.; Holmes, C.; Vaicik, M.; Turturro, M.; Jurkevich, A.; Sinha, S.; Ezashi, T.; Papavasiliou, G.; Brey, E.; Holmes, T.
2015-03-01
3D image reconstruction using light microscope modalities without exogenous contrast agents is proposed and investigated as an approach to produce 3D images of biological samples for live imaging applications. Multimodality and multispectral imaging, used in concert with this 3D optical sectioning approach is also proposed as a way to further produce contrast that could be specific to components in the sample. The methods avoid usage of contrast agents. Contrast agents, such as fluorescent or absorbing dyes, can be toxic to cells or alter cell behavior. Current modes of producing 3D image sets from a light microscope, such as 3D deconvolution algorithms and confocal microscopy generally require contrast agents. Zernike phase contrast (ZPC), transmitted light brightfield (TLB), darkfield microscopy and others can produce contrast without dyes. Some of these modalities have not previously benefitted from 3D image reconstruction algorithms, however. The 3D image reconstruction algorithm is based on an underlying physical model of scattering potential, expressed as the sample's 3D absorption and phase quantities. The algorithm is based upon optimizing an objective function - the I-divergence - while solving for the 3D absorption and phase quantities. Unlike typical deconvolution algorithms, each microscope modality, such as ZPC or TLB, produces two output image sets instead of one. Contrast in the displayed image and 3D renderings is further enabled by treating the multispectral/multimodal data as a feature set in a mathematical formulation that uses the principal component method of statistics.
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.
3D FaceCam: a fast and accurate 3D facial imaging device for biometrics applications
Geng, Jason; Zhuang, Ping; May, Patrick; Yi, Steven; Tunnell, David
2004-08-01
Human faces are fundamentally three-dimensional (3D) objects, and each face has its unique 3D geometric profile. The 3D geometric features of a human face can be used, together with its 2D texture, for rapid and accurate face recognition purposes. Due to the lack of low-cost and robust 3D sensors and effective 3D facial recognition (FR) algorithms, almost all existing FR systems use 2D face images. Genex has developed 3D solutions that overcome the inherent problems in 2D while also addressing limitations in other 3D alternatives. One important aspect of our solution is a unique 3D camera (the 3D FaceCam) that combines multiple imaging sensors within a single compact device to provide instantaneous, ear-to-ear coverage of a human face. This 3D camera uses three high-resolution CCD sensors and a color encoded pattern projection system. The RGB color information from each pixel is used to compute the range data and generate an accurate 3D surface map. The imaging system uses no moving parts and combines multiple 3D views to provide detailed and complete 3D coverage of the entire face. Images are captured within a fraction of a second and full-frame 3D data is produced within a few seconds. This described method provides much better data coverage and accuracy in feature areas with sharp features or details (such as the nose and eyes). Using this 3D data, we have been able to demonstrate that a 3D approach can significantly improve the performance of facial recognition. We have conducted tests in which we have varied the lighting conditions and angle of image acquisition in the "field." These tests have shown that the matching results are significantly improved when enrolling a 3D image rather than a single 2D image. With its 3D solutions, Genex is working toward unlocking the promise of powerful 3D FR and transferring FR from a lab technology into a real-world biometric solution.
Are 3-D Movies Bad for Your Eyes?
Full Text Available ... viewer has a problem with focusing or depth perception. Also, the techniques used to create the 3- ... or other conditions that persistently inhibit focusing, depth perception or normal 3-D vision, would have difficulty ...
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
Zhang, Tao; Hartl, Caroline; Frank, Kilian; Heuer-Jungemann, Amelie; Fischer, Stefan; Nickels, Philipp C; Nickel, Bert; Liedl, Tim
2018-05-18
3D crystals assembled entirely from DNA provide a route to design materials on a molecular level and to arrange guest particles in predefined lattices. This requires design schemes that provide high rigidity and sufficiently large open guest space. A DNA-origami-based "tensegrity triangle" structure that assembles into a 3D rhombohedral crystalline lattice with an open structure in which 90% of the volume is empty space is presented here. Site-specific placement of gold nanoparticles within the lattice demonstrates that these crystals are spacious enough to efficiently host 20 nm particles in a cavity size of 1.83 × 10 5 nm 3 , which would also suffice to accommodate ribosome-sized macromolecules. The accurate assembly of the DNA origami lattice itself, as well as the precise incorporation of gold particles, is validated by electron microscopy and small-angle X-ray scattering experiments. The results show that it is possible to create DNA building blocks that assemble into lattices with customized geometry. Site-specific hosting of nano objects in the optically transparent DNA lattice sets the stage for metamaterial and structural biology applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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.
3-D magnetic field calculations for wiggglers using MAGNUS-3D
International Nuclear Information System (INIS)
Pissanetzky, S.; Tompkins, P.
1988-01-01
The recent but steady trend toward increased magnetic and geometric complexity in the design of wigglers and undulators, of which tapered wigglers, hybrid structures, laced electromagnetic wigglers, magnetic cladding, twisters and magic structures are examples, has caused a need for reliable 3-D computer models and a better understanding of the behavior of magnetic systems in three dimensions. The capabilities of the MAGNUS-3D Group of Programs are ideally suited to solve this class of problems and provide insight into 3-D effects. MAGNUS-3D can solve any problem of Magnetostatics involving permanent magnets, linear or nonlinear ferromagnetic materials and electric conductors of any shape in space. The magnetic properties of permanent magnets are described by the complete nonlinear demagnetization curve as provided by the manufacturer, or, at the user's choice, by a simpler approximation involving the coercive force, the residual induction and the direction of magnetization. The ferromagnetic materials are described by a magnetization table and an accurate interpolation relation. An internal library with properties of common industrial steels is available. The conductors are independent of the mesh and are described in terms of conductor elements from an internal library
International Nuclear Information System (INIS)
Larry Lawrence; Bruce Miller
2004-01-01
The Lott Ranch 3D seismic prospect located in Garza County, Texas is a project initiated in September of 1991 by the J.M. Huber Corp., a petroleum exploration and production company. By today's standards the 126 square mile project does not seem monumental, however at the time it was conceived it was the most intensive land 3D project ever attempted. Acquisition began in September of 1991 utilizing GEO-SEISMIC, INC., a seismic data contractor. The field parameters were selected by J.M. Huber, and were of a radical design. The recording instruments used were GeoCor IV amplifiers designed by Geosystems Inc., which record the data in signed bit format. It would not have been practical, if not impossible, to have processed the entire raw volume with the tools available at that time. The end result was a dataset that was thought to have little utility due to difficulties in processing the field data. In 1997, Yates Energy Corp. located in Roswell, New Mexico, formed a partnership to further develop the project. Through discussions and meetings with Pinnacle Seismic, it was determined that the original Lott Ranch 3D volume could be vastly improved upon reprocessing. Pinnacle Seismic had shown the viability of improving field-summed signed bit data on smaller 2D and 3D projects. Yates contracted Pinnacle Seismic Ltd. to perform the reprocessing. This project was initiated with high resolution being a priority. Much of the potential resolution was lost through the initial summing of the field data. Modern computers that are now being utilized have tremendous speed and storage capacities that were cost prohibitive when this data was initially processed. Software updates and capabilities offer a variety of quality control and statics resolution, which are pertinent to the Lott Ranch project. The reprocessing effort was very successful. The resulting processed data-set was then interpreted using modern PC-based interpretation and mapping software. Production data, log data
Integrated Biogeomorphological Modeling Using Delft3D
Ye, Q.; Jagers, B.
2011-12-01
The skill of numerical morphological models has improved significantly from the early 2D uniform, total load sediment models (with steady state or infrequent wave updates) to recent 3D hydrodynamic models with multiple suspended and bed load sediment fractions and bed stratigraphy (online coupled with waves). Although there remain many open questions within this combined field of hydro- and morphodynamics, we observe an increasing need to include biological processes in the overall dynamics. In riverine and inter-tidal environments, there is often an important influence by riparian vegetation and macrobenthos. Over the past decade more and more researchers have started to extend the simulation environment with wrapper scripts and other quick code hacks to estimate their influence on morphological development in coastal, estuarine and riverine environments. Although one can in this way quickly analyze different approaches, these research tools have generally not been designed with reuse, performance and portability in mind. We have now implemented a reusable, flexible, and efficient two-way link between the Delft3D open source framework for hydrodynamics, waves and morphology, and the water quality and ecology modules. The same link will be used for 1D, 2D and 3D modeling on networks and both structured and unstructured grids. We will describe the concepts of the overall system, and illustrate it with some first results.
Development of 3D CFD code based on structured non-orthogonal grids
International Nuclear Information System (INIS)
Vaidya, Abhijeet Mohan; Maheshwari, Naresh Kumar; Rama Rao, A.
2016-01-01
Most of the nuclear industry problems involve complex geometries. Solution of flow and heat transfer over complex geometries is a very important requirement for designing new reactor systems. Hence development of a general purpose three dimensional (3D) CFD code is undertaken. For handling complex shape of computational domain, implementation on structured non-orthogonal coordinates is being done. The code is validated by comparing its results for 3D inclined lid driven cavity at different inclination angles and Reynolds numbers with OpenFOAM results. This paper contains formulation and validation of the new code developed. (author)
3D motion analysis via energy minimization
Energy Technology Data Exchange (ETDEWEB)
Wedel, Andreas
2009-10-16
This work deals with 3D motion analysis from stereo image sequences for driver assistance systems. It consists of two parts: the estimation of motion from the image data and the segmentation of moving objects in the input images. The content can be summarized with the technical term machine visual kinesthesia, the sensation or perception and cognition of motion. In the first three chapters, the importance of motion information is discussed for driver assistance systems, for machine vision in general, and for the estimation of ego motion. The next two chapters delineate on motion perception, analyzing the apparent movement of pixels in image sequences for both a monocular and binocular camera setup. Then, the obtained motion information is used to segment moving objects in the input video. Thus, one can clearly identify the thread from analyzing the input images to describing the input images by means of stationary and moving objects. Finally, I present possibilities for future applications based on the contents of this thesis. Previous work in each case is presented in the respective chapters. Although the overarching issue of motion estimation from image sequences is related to practice, there is nothing as practical as a good theory (Kurt Lewin). Several problems in computer vision are formulated as intricate energy minimization problems. In this thesis, motion analysis in image sequences is thoroughly investigated, showing that splitting an original complex problem into simplified sub-problems yields improved accuracy, increased robustness, and a clear and accessible approach to state-of-the-art motion estimation techniques. In Chapter 4, optical flow is considered. Optical flow is commonly estimated by minimizing the combined energy, consisting of a data term and a smoothness term. These two parts are decoupled, yielding a novel and iterative approach to optical flow. The derived Refinement Optical Flow framework is a clear and straight-forward approach to
Investigating the Problem of Skill Generalization: Literature Review III.
Haring, Norris
The third in a series of literature reviews, this monograph presents three articles on skill generalization among individuals with severe disabilities. Kathleen A. Liberty analyzes the results of 15 studies to determine how teaching self-control affected students' performance in training and generalization, "Behavior-Control of Stimulus Events to…
A branch-and-cut-and-price algorithm for the mixed capacitated general routing problem
DEFF Research Database (Denmark)
Bach, Lukas; Wøhlk, Sanne; Lysgaard, Jens
2016-01-01
In this paper, we consider the Mixed Capacitated General Routing Problem which is a combination of the Capacitated Vehicle Routing Problem and the Capacitated Arc Routing Problem. The problem is also known as the Node, Edge, and Arc Routing Problem. We propose a Branch-and-Cut-and-Price algorithm...
3D biometrics systems and applications
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
International Nuclear Information System (INIS)
Able, E.
1990-01-01
This paper reports on the development of telerobotic techniques that can be used in the nuclear industry. The approach has been to apply available equipment, modify available equipment, or design and build anew. The authors have successfully built an input controller which can be used with standard industrial robots, converting them into telerobots. A clean room industrial robot has been re-engineered into an advanced telerobot engineered for the nuclear industry, using a knowledge of radiation tolerance design principles and collaboration with the manufacturer. A powerful hydraulic manipulator has been built to respond to a need for more heavy duty devices for in-cell handling. A variety of easy to use 3-D TV systems has been developed
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.
3D reconstruction of tensors and vectors
International Nuclear Information System (INIS)
Defrise, Michel; Gullberg, Grant T.
2005-01-01
Here we have developed formulations for the reconstruction of 3D tensor fields from planar (Radon) and line-integral (X-ray) projections of 3D vector and tensor fields. Much of the motivation for this work is the potential application of MRI to perform diffusion tensor tomography. The goal is to develop a theory for the reconstruction of both Radon planar and X-ray or line-integral projections because of the flexibility of MRI to obtain both of these type of projections in 3D. The development presented here for the linear tensor tomography problem provides insight into the structure of the nonlinear MRI diffusion tensor inverse problem. A particular application of tensor imaging in MRI is the potential application of cardiac diffusion tensor tomography for determining in vivo cardiac fiber structure. One difficulty in the cardiac application is the motion of the heart. This presents a need for developing future theory for tensor tomography in a motion field. This means developing a better understanding of the MRI signal for diffusion processes in a deforming media. The techniques developed may allow the application of MRI tensor tomography for the study of structure of fiber tracts in the brain, atherosclerotic plaque, and spine in addition to fiber structure in the heart. However, the relations presented are also applicable to other fields in medical imaging such as diffraction tomography using ultrasound. The mathematics presented can also be extended to exponential Radon transform of tensor fields and to other geometric acquisitions such as cone beam tomography of tensor fields
Embedding complex objects with 3d printing
Hussain, Muhammad Mustafa
2017-10-12
A CMOS technology-compatible fabrication process for flexible CMOS electronics embedded during additive manufacturing (i.e. 3D printing). A method for such a process may include printing a first portion of a 3D structure; pausing the step of printing the 3D structure to embed the flexible silicon substrate; placing the flexible silicon substrate in a cavity of the first portion of the 3D structure to embed the flexible silicon substrate in the 3D structure; and resuming the step of printing the 3D structure to form the second portion of the 3D structure.
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
Simple shape space for 3D face registration
Košir, Andrej; Perkon, Igor; Bracun, Drago; Tasic, Jurij; Mozina, Janez
2009-09-01
Three dimensional (3D) face recognition is a topic getting increasing interest in biometric applications. In our research framework we developed a laser scanner that provides 3D cloud information and texture data. In a user scenario with cooperative subjects with indoor light conditions, we address three problems of 3D face biometrics: the face registration, the formulation of a shape space together with a special designed gradient algorithm and the impact of initial approximation to the convergence of a registration algorithm. By defining the face registration as a problem of aligning a 3D data cloud with a predefined reference template, we solve the registration problem with a second order gradient algorithm working on a shape space designed for reducing the computational complexity of the method.
On generalizations of network design problems with degree bounds
Bansal, N.; Khandekar, R.; Könemann, J.; Nagarajan, V.; Peis, B.
2013-01-01
Iterative rounding and relaxation have arguably become the method of choice in dealing with unconstrained and constrained network design problems. In this paper we extend the scope of the iterative relaxation method in two directions: (1) by handling more complex degree constraints in the minimum
On generalizations of network design problems with degree bounds
N. Bansal (Nikhil); R. Khandekar; J. Könemann (Jochen); V. Nagarajan; B. Peis
2013-01-01
htmlabstractIterative rounding and relaxation have arguably become the method of choice in dealing with unconstrained and constrained network design problems. In this paper we extend the scope of the iterative relaxation method in two directions: (1) by handling more complex degree constraints in
Optimal portfolio selection for general provisioning and terminal wealth problems
van Weert, K.; Dhaene, J.; Goovaerts, M.
2010-01-01
In Dhaene et al. (2005), multiperiod portfolio selection problems are discussed, using an analytical approach to find optimal constant mix investment strategies in a provisioning or a savings context. In this paper we extend some of these results, investigating some specific, real-life situations.
Optimal portfolio selection for general provisioning and terminal wealth problems
van Weert, K.; Dhaene, J.; Goovaerts, M.
2009-01-01
In Dhaene et al. (2005), multiperiod portfolio selection problems are discussed, using an analytical approach to find optimal constant mix investment strategies in a provisioning or savings context. In this paper we extend some of these results, investigating some specific, real-life situations. The
On a problem of Berenstein-Gay and its generalizations
International Nuclear Information System (INIS)
Volchkov, Valerii V; Volchkov, Vitaly V
2010-01-01
We obtain a solution of the Berenstein-Gay problem on the local analogue of spectral analysis on Riemannian symmetric spaces X of rank 1. The proof is based on constructing transmutation maps connected with eigenfunction expansions of the Laplace-Beltrami operator on X.
Natural fibre composites for 3D Printing
Pandey, Kapil
2015-01-01
3D printing has been common option for prototyping. Not all the materials are suitable for 3D printing. Various studies have been done and still many are ongoing regarding the suitability of the materials for 3D printing. This thesis work discloses the possibility of 3D printing of certain polymer composite materials. The main objective of this thesis work was to study the possibility for 3D printing the polymer composite material composed of natural fibre composite and various different ...
3D-printed upper limb prostheses: a review.
Ten Kate, Jelle; Smit, Gerwin; Breedveld, Paul
2017-04-01
This paper aims to provide an overview with quantitative information of existing 3D-printed upper limb prostheses. We will identify the benefits and drawbacks of 3D-printed devices to enable improvement of current devices based on the demands of prostheses users. A review was performed using Scopus, Web of Science and websites related to 3D-printing. Quantitative information on the mechanical and kinematic specifications and 3D-printing technology used was extracted from the papers and websites. The overview (58 devices) provides the general specifications, the mechanical and kinematic specifications of the devices and information regarding the 3D-printing technology used for hands. The overview shows prostheses for all different upper limb amputation levels with different types of control and a maximum material cost of $500. A large range of various prostheses have been 3D-printed, of which the majority are used by children. Evidence with respect to the user acceptance, functionality and durability of the 3D-printed hands is lacking. Contrary to what is often claimed, 3D-printing is not necessarily cheap, e.g., injection moulding can be cheaper. Conversely, 3D-printing provides a promising possibility for individualization, e.g., personalized socket, colour, shape and size, without the need for adjusting the production machine. Implications for rehabilitation Upper limb deficiency is a condition in which a part of the upper limb is missing as a result of a congenital limb deficiency of as a result of an amputation. A prosthetic hand can restore some of the functions of a missing limb and help the user in performing activities of daily living. Using 3D-printing technology is one of the solutions to manufacture hand prostheses. This overview provides information about the general, mechanical and kinematic specifications of all the devices and it provides the information about the 3D-printing technology used to print the hands.
Contribution of radiobiology to the problem of general fitness
International Nuclear Information System (INIS)
Vacha, J.
1976-01-01
On the basis of the present scarce literary data it can be taken as proved that between the numerous properties of the organism usually considered as biologically valuable (high fertility, longevity, higher body weight, resistance to fasting, radiation, and infection agents, certain favorable parameters of CNS) there exist many single and multiple positive correlations. The existence of these correlations allows for the introduction of the working concept of general fitness, stimulating further interdisciplinary research in this field important both in practice and theory. Most correlated manifestations of fitness demonstrated a masked influence of the organism's genotype even though the manner of this manifestation on the phenotype level remains considerably obscure. The efficiency of the haematopoietic system is doubtless one of the mechanisms of general fitness; it is determined by the very complex coordination of several cytokinetic parameters. Important factors are the efficiency of regulation mechanisms at CNS level, the endocrine system, and the regulators of cell populations. Generally highest fitness is connected with a ''balanced'' regulation type, which is characterized by optimal activation of the homeostatic regulation mechanism. In studying the causes of general fitness a systems approach is inevitable which evaluates the levels of individual factors not ''mechanically'' or linearly but from the point of view of the needs of the whole organism and with the application of concepts established by the systems theory (e.g. by the theory of automatic regulation). The sensitivity of an organism to irradiation with ionizing radiation turns out to be a suitable criterion of its general fitness. (author)
3-D discrete analytical ridgelet transform.
Helbert, David; Carré, Philippe; Andres, Eric
2006-12-01
In this paper, we propose an implementation of the 3-D Ridgelet transform: the 3-D discrete analytical Ridgelet transform (3-D DART). This transform uses the Fourier strategy for the computation of the associated 3-D discrete Radon transform. The innovative step is the definition of a discrete 3-D transform with the discrete analytical geometry theory by the construction of 3-D discrete analytical lines in the Fourier domain. We propose two types of 3-D discrete lines: 3-D discrete radial lines going through the origin defined from their orthogonal projections and 3-D planes covered with 2-D discrete line segments. These discrete analytical lines have a parameter called arithmetical thickness, allowing us to define a 3-D DART adapted to a specific application. Indeed, the 3-D DART representation is not orthogonal, It is associated with a flexible redundancy factor. The 3-D DART has a very simple forward/inverse algorithm that provides an exact reconstruction without any iterative method. In order to illustrate the potentiality of this new discrete transform, we apply the 3-D DART and its extension to the Local-DART (with smooth windowing) to the denoising of 3-D image and color video. These experimental results show that the simple thresholding of the 3-D DART coefficients is efficient.
Computer-controlled 3-D treatment delivery
International Nuclear Information System (INIS)
Fraass, Benedick A.
1995-01-01
Purpose/Objective: This course will describe the use of computer-controlled treatment delivery techniques for treatment of patients with sophisticated conformal therapy. In particular, research and implementation issues related to clinical use of computer-controlled conformal radiation therapy (CCRT) techniques will be discussed. The possible/potential advantages of CCRT techniques will be highlighted using results from clinical 3-D planning studies. Materials and Methods: In recent years, 3-D treatment planning has been used to develop and implement 3-D conformal therapy treatment techniques, and studies based on these conformal treatments have begun to show the promise of conformal therapy. This work has been followed by the development of commercially-available multileaf collimator and computer control systems for treatment machines. Using these (and other) CCRT devices, various centers are beginning to clinically use complex computer-controlled treatments. Both research and clinical CCRT treatment techniques will be discussed in this presentation. General concepts and requirements for CCRT will be mentioned. Developmental and clinical experience with CCRT techniques from a number of centers will be utilized. Results: Treatment planning, treatment preparation and treatment delivery must be approached in an integrated fashion in order to clinically implement CCRT treatment techniques, and the entire process will be discussed. Various CCRT treatment methodologies will be reviewed from operational, dosimetric, and technical points of view. The discussion will concentrate on CCRT techniques which are likely to see rather wide dissemination over the next several years, including particularly the use of multileaf collimators (MLC), dynamic and segmental conformal therapy, conformal field shaping, and other related techniques. More advanced CCRT techniques, such as the use of individualized intensity modulation of beams or segments, and the use of computer
Infrared problems in two-dimensional generalized σ-models
International Nuclear Information System (INIS)
Curci, G.; Paffuti, G.
1989-01-01
We study the correlations of the energy-momentum tensor for classically conformally invariant generalized σ-models in the Wilson operator-product-expansion approach. We find that these correlations are, in general, infrared divergent. The absence of infrared divergences is obtained, as one can expect, for σ-models on a group manifold or for σ-models with a string-like interpretation. Moreover, the infrared divergences spoil the naive scaling arguments used by Zamolodchikov in the demonstration of the C-theorem. (orig.)
3D Virtual Dig: a 3D Application for Teaching Fieldwork in Archaeology
Directory of Open Access Journals (Sweden)
Paola Di Giuseppantonio Di Franco
2012-12-01
Full Text Available Archaeology is a material, embodied discipline; communicating this experience is critical to student success. In the context of lower-division archaeology courses, the present study examines the efficacy of 3D virtual and 2D archaeological representations of digs. This presentation aims to show a 3D application created to teach the archaeological excavation process to freshmen students. An archaeological environment was virtually re-created in 3D, and inserted in a virtual reality software application that allows users to work with the reconstructed excavation area. The software was tested in class for teaching the basics of archaeological fieldwork. The application interface is user-friendly and especially easy for 21st century students. The study employed a pre-survey, post-test, and post-survey design, used to understand the students' previous familiarity with archaeology, and test their awareness after the use of the application. Their level of knowledge was then compared with that of those students who had accessed written material only. This case-study demonstrates how a digital approach to laboratory work can positively affect student learning. Increased abilities to complete ill-defined problems (characteristic of the high-order thinking in the field, can, in fact, be demonstrated. 3D Virtual reconstruction serves, then, as an important bridge from traditional coursework to fieldwork.
The global existence problem and cosmic censorship in general relativity
International Nuclear Information System (INIS)
Moncrief, V.; Eardley, D.M.
1981-01-01
Two global existence conjectures for the Einstein equations are formulated and their relevance to the cosmic censorship conjecture discussed. It is argued that the reformulation of the cosmic censorship conjecture as a global existence problem renders it more amenable to direct analytical attack. To demonstrate the facility of this approach the cosmological version of the global existence conjecture is proved for the Gowdy spacetimes on T 3 X R. (author)
Development of 3D browsing and interactive web system
Shi, Xiaonan; Fu, Jian; Jin, Chaolin
2017-09-01
In the current market, users need to download specific software or plug-ins to browse the 3D model, and browsing the system may be unstable, and it cannot be 3D model interaction issues In order to solve this problem, this paper presents a solution to the interactive browsing of the model in the server-side parsing model, and when the system is applied, the user only needs to input the system URL and upload the 3D model file to operate the browsing The server real-time parsing 3D model, the interactive response speed, these completely follows the user to walk the minimalist idea, and solves the current market block 3D content development question.
Computational optical tomography using 3-D deep convolutional neural networks
Nguyen, Thanh; Bui, Vy; Nehmetallah, George
2018-04-01
Deep convolutional neural networks (DCNNs) offer a promising performance for many image processing areas, such as super-resolution, deconvolution, image classification, denoising, and segmentation, with outstanding results. Here, we develop for the first time, to our knowledge, a method to perform 3-D computational optical tomography using 3-D DCNN. A simulated 3-D phantom dataset was first constructed and converted to a dataset of phase objects imaged on a spatial light modulator. For each phase image in the dataset, the corresponding diffracted intensity image was experimentally recorded on a CCD. We then experimentally demonstrate the ability of the developed 3-D DCNN algorithm to solve the inverse problem by reconstructing the 3-D index of refraction distributions of test phantoms from the dataset from their corresponding diffraction patterns.
Visualization of RELAP5-3D best estimate code
International Nuclear Information System (INIS)
Mesina, G.L.
2004-01-01
The Idaho National Engineering Laboratory has developed a number of nuclear plant analysis codes such as RELAP5-3D, SCDAP/RELAP5-3D, and FLUENT/RELAP5-3D that have multi-dimensional modeling capability. The output of these codes is very difficult to analyze without the aid of visualization tools. The RELAP5-3D Graphical User Interface (RGUI) displays these calculations on plant images, functional diagrams, graphs, and by other means. These representations of the data enhance the analysts' ability to recognize plant behavior visually and reduce the difficulty of analyzing complex three-dimensional models. This paper describes the Graphical User Interface system for the RELAP5-3D suite of Best Estimate codes. The uses of the Graphical User Interface are illustrated. Examples of user problems solved by use of this interface are given. (author)
General problems of dynamics and control of vibratory gyroscopes
CSIR Research Space (South Africa)
Shatalov, MY
2008-05-01
Full Text Available A general model of operation of vibratory gyroscopes, which is applicable to a broad class of instruments, including cylindrical, disc and micro-machined gyros, is formulated on the basis of analysis of dynamics and control of a hemispherical...
General Systems Theory Approaches to Organizations: Some Problems in Application
Peery, Newman S., Jr.
1975-01-01
Considers the limitations of General Systems Theory (GST) as a major paradigm within administrative theory and concludes that most systems formulations overemphasize growth and show little appreciation for intraorganizational conflict, diversity of values, and political action within organizations. Suggests that these limitations are mainly due to…
The problem of diagnostic variability in general practice.
Crombie, D L; Cross, K W; Fleming, D M
1992-08-01
The aim was to examine the scale, source, and relevance of variation between general practices in respect of the rates with which patients consulted with illnesses falling in each of several diagnostic groups. This study involved a general practice morbidity survey conducted over two years, 1970-72. All patients who consulted their general practitioners were identified and the number of these who consulted with diagnoses attributable to each of the 18 main chapters of the International classification of diseases were counted. Patients who consulted for more than one diagnosis within a chapter were counted once only; those who consulted for one or more diagnoses in each of several chapters were counted once for each chapter. This was a national survey involving general practitioners in England and Wales. The study involved 214,524 patients from 53 selected general practices (115 doctors) who were registered with their general practitioners for the whole of the year 1970-71 and for whom their morbidity data had been linked with their social data from the 1971 census. Using the numbers of patients on the practice lists as denominators, practice patient consulting rates (PPCR) were calculated for each practice and for each ICD chapter. Variability in chapter PPCR was examined by calculating coefficients of variation and, after allowance for random variation, coefficients of residual variation. There were large interpractice (doctor) variations in all chapter rates. These variations were only marginally attributable to: chance; different age, sex and social class mixes of practice populations; geographical locations; and practice organisation. The rates were, however, consistent from one year to the next for any one practice. Approximately half of the interpractice (doctor) diagnostic variability was associated with overall patient consulting behaviour. When the effects of this behaviour were discounted, any major residual diagnostic variability was confined largely to
Streamlining of the RELAP5-3D Code
International Nuclear Information System (INIS)
Mesina, George L; Hykes, Joshua; Guillen, Donna Post
2007-01-01
RELAP5-3D is widely used by the nuclear community to simulate general thermal hydraulic systems and has proven to be so versatile that the spectrum of transient two-phase problems that can be analyzed has increased substantially over time. To accommodate the many new types of problems that are analyzed by RELAP5-3D, both the physics and numerical methods of the code have been continuously improved. In the area of computational methods and mathematical techniques, many upgrades and improvements have been made decrease code run time and increase solution accuracy. These include vectorization, parallelization, use of improved equation solvers for thermal hydraulics and neutron kinetics, and incorporation of improved library utilities. In the area of applied nuclear engineering, expanded capabilities include boron and level tracking models, radiation/conduction enclosure model, feedwater heater and compressor components, fluids and corresponding correlations for modeling Generation IV reactor designs, and coupling to computational fluid dynamics solvers. Ongoing and proposed future developments include improvements to the two-phase pump model, conversion to FORTRAN 90, and coupling to more computer programs. This paper summarizes the general improvements made to RELAP5-3D, with an emphasis on streamlining the code infrastructure for improved maintenance and development. With all these past, present and planned developments, it is necessary to modify the code infrastructure to incorporate modifications in a consistent and maintainable manner. Modifying a complex code such as RELAP5-3D to incorporate new models, upgrade numerics, and optimize existing code becomes more difficult as the code grows larger. The difficulty of this as well as the chance of introducing errors is significantly reduced when the code is structured. To streamline the code into a structured program, a commercial restructuring tool, FOR( ) STRUCT, was applied to the RELAP5-3D source files. The
Crowdsourcing Based 3d Modeling
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.
CROWDSOURCING BASED 3D MODELING
Directory of Open Access Journals (Sweden)
A. Somogyi
2016-06-01
Full Text Available 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.
Neurotoxicity of general anesthetics: A modern view of the problem
Directory of Open Access Journals (Sweden)
A. M. Ovezov
2015-01-01
Full Text Available All general anesthetics routinely used in clinical practice are noted to have a neurotoxic effect on the brain in different animal species including primates. The negative effects observed both in young and sexually mature animals include apoptotic neuronal cell death, suppression of neurogenesis and gliogenesis, neuroinflammation, as well as learning and memory impairments. A number of epidemiologic surveys have established an association between anesthesia in patients younger than 3 to 4 years and subsequent learning disabilities and language disorders whereas others have not found this link. In middle-aged and elderly patients, anesthesia is frequently associated with the development of postoperative cognitive dysfunction. The key component of its pathogenesis (general anesthesia itself or other factors, such as operative injury, an inflammatory response, pain syndrome, intraoperative complications, underlying disease in a patient remains unelucidated. It is concluded that there is a need for additional experimental and clinical studies of the pathogenesis of these undesirable phenomena to be prevented and corrected.
TeCo3D: a 3D telecooperation application based on VRML and Java
Mauve, Martin
1998-12-01
In this paper we present a method for sharing collaboration- unaware VRML content, e.g. 3D models which were not specifically developed for use in a distributed environment. This functionality is an essential requirement for the inclusion of arbitrary VRML content, as generated by standard CAD or animation software, into teleconferencing sessions. We have developed a 3D TeleCooperation (TeCo3D) prototype to demonstrate the feasibility of our approach. The basic services provided by the prototype are the distribution of cooperation unaware VRML content, the sharing of user interactions, and the joint viewing of the content. In order to achieve maximum portability, the prototype was developed completely in Java. This paper presents general aspects of sharing VRML content as well as the concepts, the architecture and the services of the TeCo3D prototype. Our approach relies on existing VRML browsers as the VRML presentation and execution engines while reliable multicast is used as the means of communication to provide for scalability.
International Nuclear Information System (INIS)
Zakharov, A.V.; Singatullin, R.S.
1981-01-01
The inverse problem is solved in general relativity theory (GRT) consisting in determining the metric and potentials of an electromagnetic field by their values in the nonsingular point of the V 4 space and present functions, being the generalized momenta of a test charged particle. The Hamilton-Jacobi equation for a test charged particle in GRT is used. The general form of the generalized momentum dependence on the initial values is determined. It is noted that the inverse problem solution of dynamics in GRT contains arbitrariness which depends on the choice of the metric and potential values of the electromagnetic field in the nonsingular point [ru
Discussion of Source Reconstruction Models Using 3D MCG Data
Melis, Massimo De; Uchikawa, Yoshinori
In this study we performed the source reconstruction of magnetocardiographic signals generated by the human heart activity to localize the site of origin of the heart activation. The localizations were performed in a four compartment model of the human volume conductor. The analyses were conducted on normal subjects and on a subject affected by the Wolff-Parkinson-White syndrome. Different models of the source activation were used to evaluate whether a general model of the current source can be applied in the study of the cardiac inverse problem. The data analyses were repeated using normal and vector component data of the MCG. The results show that a distributed source model has the better accuracy in performing the source reconstructions, and that 3D MCG data allow finding smaller differences between the different source models.
Variational regularization of 3D data experiments with Matlab
Montegranario, Hebert
2014-01-01
Variational Regularization of 3D Data provides an introduction to variational methods for data modelling and its application in computer vision. In this book, the authors identify interpolation as an inverse problem that can be solved by Tikhonov regularization. The proposed solutions are generalizations of one-dimensional splines, applicable to n-dimensional data and the central idea is that these splines can be obtained by regularization theory using a trade-off between the fidelity of the data and smoothness properties.As a foundation, the authors present a comprehensive guide to the necessary fundamentals of functional analysis and variational calculus, as well as splines. The implementation and numerical experiments are illustrated using MATLAB®. The book also includes the necessary theoretical background for approximation methods and some details of the computer implementation of the algorithms. A working knowledge of multivariable calculus and basic vector and matrix methods should serve as an adequat...
3D-printing technologies for electrochemical applications.
Ambrosi, Adriano; Pumera, Martin
2016-05-21
Since its conception during the 80s, 3D-printing, also known as additive manufacturing, has been receiving unprecedented levels of attention and interest from industry and research laboratories. This is in addition to end users, who have benefited from the pervasiveness of desktop-size and relatively cheap printing machines available. 3D-printing enables almost infinite possibilities for rapid prototyping. Therefore, it has been considered for applications in numerous research fields, ranging from mechanical engineering, medicine, and materials science to chemistry. Electrochemistry is another branch of science that can certainly benefit from 3D-printing technologies, paving the way for the design and fabrication of cheaper, higher performing, and ubiquitously available electrochemical devices. Here, we aim to provide a general overview of the most commonly available 3D-printing methods along with a review of recent electrochemistry related studies adopting 3D-printing as a possible rapid prototyping fabrication tool.
Vrste i tehnike 3D modeliranja
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...
Kuvaus 3D-tulostamisesta hammastekniikassa
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...
Ptychography: early history and 3D scattering effects
Rodenburg, J. M.
2012-01-01
The coherent diffractive imaging method of ptychography is first reviewed from a general historical perspective. Much more recent progress in extending the method to the 3D scattering geometry and the super-resolution configuration is also described. Ptychography was originally conceived by Walter Hoppe as a solution to the X-ray or electron crystallography phase problem. Although the existence of this type of phase information was clearly evident in the early 1970s, the technique was not implemented at atomic-scale wavelengths until the 1990s, and then only in a way that was computationally inefficient, especially in view of the limited size of computers at that time. Fast and efficient ptychographic algorithms were developed much later, in the mid-2000s. The extremes of crystallography ptychography, which only requires two diffraction patterns, and the Wigner Distribution Deconvolution (WDDC) method, which needs a diffraction pattern for every pixel of the final reconstruction, are described. Very recent work relating to the application of serial iterative to 3D inversion are also described.
Implementing a 3D printing service in a biomedical library.
Walker, Verma
2017-01-01
Three-dimensional (3D) printing is opening new opportunities in biomedicine by enabling creative problem solving, faster prototyping of ideas, advances in tissue engineering, and customized patient solutions. The National Institutes of Health (NIH) Library purchased a Makerbot Replicator 2 3D printer to give scientists a chance to try out this technology. To launch the service, the library offered training, conducted a survey on service model preferences, and tracked usage and class attendance. 3D printing was very popular, with new lab equipment prototypes being the most common model type. Most survey respondents indicated they would use the service again and be willing to pay for models. There was high interest in training for 3D modeling, which has a steep learning curve. 3D printers also require significant care and repairs. NIH scientists are using 3D printing to improve their research, and it is opening new avenues for problem solving in labs. Several scientists found the 3D printer so helpful they bought one for their labs. Having a printer in a central and open location like a library can help scientists, doctors, and students learn how to use this technology in their work.
Implementing a 3D printing service in a biomedical library
Directory of Open Access Journals (Sweden)
Verma Walker, MLIS
2017-01-01
Full Text Available Three-dimensional (3D printing is opening new opportunities in biomedicine by enabling creative problem solving, faster prototyping of ideas, advances in tissue engineering, and customized patient solutions. The National Institutes of Health (NIH Library purchased a Makerbot Replicator 2 3D printer to give scientists a chance to try out this technology. To launch the service, the library offered training, conducted a survey on service model preferences, and tracked usage and class attendance. 3D printing was very popular, with new lab equipment prototypes being the most common model type. Most survey respondents indicated they would use the service again and be willing to pay for models. There was high interest in training for 3D modeling, which has a steep learning curve. 3D printers also require significant care and repairs. NIH scientists are using 3D printing to improve their research, and it is opening new avenues for problem solving in labs. Several scientists found the 3D printer so helpful they bought one for their labs. Having a printer in a central and open location like a library can help scientists, doctors, and students learn how to use this technology in their work.
General principles of neurotransmitter detection. Problems and application to catecholamines
International Nuclear Information System (INIS)
Taxi, Jacques
1976-01-01
The use of radioautography for neurotransmitter studies requires two preliminary conditions (in addition to the availability of tritiated molecules): there must be a selective uptake of the neurotransmitter itself, or of a related substance (precursor or false transmitter); the labelled substance must be preserved in situ by fixation and must not be removed by further treatments. Since the putative neurotransmitters are generally small, hydrosoluble molecules, they can be maintained in situ only if they are bound to structure made insoluble by the fixative. The technical indications are summarized so that the successive stages of experimentation can be considered in an attempt to answer the major questions posed by the experimenter
Ltaief, Hatem; Luszczek, Piotr R.; Haidar, Azzam; Dongarra, Jack
2012-01-01
This paper proposes an efficient implementation of the generalized symmetric eigenvalue problem on multicore architecture. Based on a four-stage approach and tile algorithms, the original problem is first transformed into a standard symmetric
Zantinge, E.M.; Verhaak, P.F.M.; Bakker, D.H. de; Kerssens, J.J.; Meer, K. van der; Bensing, J.M.
2007-01-01
OBJECTIVE: To investigate if general practitioners (GPs) with a higher workload are less inclined to encourage their patients to disclose psychological problems, and are less aware of their patients' psychological problems. METHODS: Data from 2095 videotaped consultations from a representative
General problems specific to hot nuclear materials research facilities
International Nuclear Information System (INIS)
Bart, G.
1996-01-01
During the sixties, governments have installed hot nuclear materials research facilities to characterize highly radioactive materials, to describe their in-pile behaviour, to develop and test new reactor core components, and to provide the industry with radioisotopes. Since then, the attitude towards the nuclear option has drastically changed and resources have become very tight. Within the changed political environment, the national research centres have defined new objectives. Given budgetary constraints, nuclear facilities have to co-operate internationally and to look for third party research assignments. The paper discusses the problems and needs within experimental nuclear research facilities as well as industrial requirements. Special emphasis is on cultural topics (definition of the scope of nuclear research facilities, the search for competitive advantages, and operational requirements), social aspects (overageing of personnel, recruitment, and training of new staff), safety related administrative and technical issues, and research needs for expertise and state of the art analytical infrastructure
General review on climate change problems: causes, potential effects
International Nuclear Information System (INIS)
Martellet, J.
1991-01-01
Greenhouse gases and greenhouse effect principles are reviewed and climate changes due to the human activities are discussed: identification of gases, human or natural causes, composition evolution in the atmosphere and relative roles of greenhouse gases. The various tools and calculations methods for evaluating the climate change due to greenhouse effect are presented. Several problems are stated: evolution of the climate structure in 2030, variations of the climatic extremes and the extreme phenomena, augmentation or diminution of the storms on a warmed planet, long term evolution of the climate. Some consequences of a climate change are reviewed: sea level raising, climate change effects on ecosystems. Precision and validity of these predictions are discussed; recommendations for diminishing the uncertainties are proposed
PLOT-3D, Graphics Subroutines for 3-D Surface Plots with Arbitrary Rotations
International Nuclear Information System (INIS)
Basinger, D.; Gvildys, J.
1975-01-01
1 - Description of problem or function: PLOT-3D is a package of sub- programs designed to draw three-dimensional surfaces from arrays of points (x,y,z). The surfaces can be drawn after arbitrary rotations about the three coordinate axes. 2 - Method of solution: PLOT-3D is a computer program to plot any surface for which each coordinate pair (x,y) is associated with a unique z in the set of points (x,y,z). It uses matrix transformation of the points to generate different views of the surface after arbitrary rotations about the three coordinate axes. Four versions of PLOT-3D are available. Output of version 1 and 3 is by film recorder. Output of version 2 and 4 is by CalComp plotter. Versions 3 and 4 do not draw lines which would be invisible to a viewer looking at an opaque surface, whereas versions 1 and 2 draw every line on the surface. 3 - Restrictions on the complexity of the problem: Versions 3 and 4 limit number of rows in arrays (x,y,z) to 100 and also number of columns in arrays (x,y,z) to 100
From 2D to 3D: Using Illumination Cones to Build 3d Face Model
International Nuclear Information System (INIS)
Xiao, S S; Jin, M
2006-01-01
To solve the problem derivate by lighting condition and position of the camera, a new method using illumination cones to build 3d face model has been proposed. Due to illumination variability, the same object can show dramatic difference even as being viewed in fixed pose. To handle this variability, an object recognition system must employ a representation that is either invariant to, or can model this variability. The proposed technique presents an appearance-based method for modeling the variability due to illumination in the images of objects. The method differs from past appearance-based methods. Evenmore, a small set of training images is used to generate a representation that the illumination cone models the complete set of images of an object with Lambertian reflectance surface under a combination of arbitrary point light sources at infinity. After building up the illumination cones, researches focus on how to present the 3d model of the face. Combining illumination and texture feature to build up 3d model of the face make it easy solving the problem in recognition of face under different pose
Evaluation of the 3d Urban Modelling Capabilities in Geographical Information Systems
Dogru, A. O.; Seker, D. Z.
2010-12-01
Geographical Information System (GIS) Technology, which provides successful solutions to basic spatial problems, is currently widely used in 3 dimensional (3D) modeling of physical reality with its developing visualization tools. The modeling of large and complicated phenomenon is a challenging problem in terms of computer graphics currently in use. However, it is possible to visualize that phenomenon in 3D by using computer systems. 3D models are used in developing computer games, military training, urban planning, tourism and etc. The use of 3D models for planning and management of urban areas is very popular issue of city administrations. In this context, 3D City models are produced and used for various purposes. However the requirements of the models vary depending on the type and scope of the application. While a high level visualization, where photorealistic visualization techniques are widely used, is required for touristy and recreational purposes, an abstract visualization of the physical reality is generally sufficient for the communication of the thematic information. The visual variables, which are the principle components of cartographic visualization, such as: color, shape, pattern, orientation, size, position, and saturation are used for communicating the thematic information. These kinds of 3D city models are called as abstract models. Standardization of technologies used for 3D modeling is now available by the use of CityGML. CityGML implements several novel concepts to support interoperability, consistency and functionality. For example it supports different Levels-of-Detail (LoD), which may arise from independent data collection processes and are used for efficient visualization and efficient data analysis. In one CityGML data set, the same object may be represented in different LoD simultaneously, enabling the analysis and visualization of the same object with regard to different degrees of resolution. Furthermore, two CityGML data sets
Gorczyk, W.; Vogt, K.
2017-12-01
Magma intrusion is a major material transfer process in Earth's continental crust. Yet, the mechanical behavior of the intruding magma and its host are a matter of debate. In this study, we present a series of numerical thermo-mechanical experiments on mafic magma emplacement in 3D.In our model, we place the magmatic source region (40 km diameter) at the base of the mantle lithosphere and connect it to the crust by a 3 km wide channel, which may have evolved at early stages of magmatism during rapid ascent of hot magmatic fluids/melts. Our results demonstrate continental crustal response due to magma intrusion. We observe change in intrusion geometries between dikes, cone-sheets, sills, plutons, ponds, funnels, finger-shaped and stock-like intrusions as well as injection time. The rheology and temperature of the host-rock are the main controlling factors in the transition between these different modes of intrusion. Viscous deformation in the warm and deep crust favours host rock displacement and magma pools along the crust-mantle boundary forming deep-seated plutons or magma ponds in the lower to middle-crust. Brittle deformation in the cool and shallow crust induces cone-shaped fractures in the host rock and enables emplacement of finger- or stock-like intrusions at shallow or intermediate depth. A combination of viscous and brittle deformation forms funnel-shaped intrusions in the middle-crust. Low-density source magma results in T-shaped intrusions in cross-section with magma sheets at the surface.
Parallel Processor for 3D Recovery from Optical Flow
Directory of Open Access Journals (Sweden)
Jose Hugo Barron-Zambrano
2009-01-01
Full Text Available 3D recovery from motion has received a major effort in computer vision systems in the recent years. The main problem lies in the number of operations and memory accesses to be performed by the majority of the existing techniques when translated to hardware or software implementations. This paper proposes a parallel processor for 3D recovery from optical flow. Its main feature is the maximum reuse of data and the low number of clock cycles to calculate the optical flow, along with the precision with which 3D recovery is achieved. The results of the proposed architecture as well as those from processor synthesis are presented.
Development of the Improving Process for the 3D Printed Structure
Kensuke Takagishi; Shinjiro Umezu
2017-01-01
The authors focus on the Fused Deposition Modeling (FDM) 3D printer because the FDM 3D printer can print the utility resin material. It can print with low cost and therefore it is the most suitable for home 3D printer. The FDM 3D printer has the problem that it produces layer grooves on the surface of the 3D printed structure. Therefore the authors developed the 3D-Chemical Melting Finishing (3D-CMF) for removing layer grooves. In this method, a pen-style device is filled with a chemical able...
3D super-virtual refraction interferometry
Lu, Kai
2014-08-05
Super-virtual refraction interferometry enhances the signal-to-noise ratio of far-offset refractions. However, when applied to 3D cases, traditional 2D SVI suffers because the stationary positions of the source-receiver pairs might be any place along the recording plane, not just along a receiver line. Moreover, the effect of enhancing the SNR can be limited because of the limitations in the number of survey lines, irregular line geometries, and azimuthal range of arrivals. We have developed a 3D SVI method to overcome these problems. By integrating along the source or receiver lines, the cross-correlation or the convolution result of a trace pair with the source or receiver at the stationary position can be calculated without the requirement of knowing the stationary locations. In addition, the amplitudes of the cross-correlation and convolution results are largely strengthened by integration, which is helpful to further enhance the SNR. In this paper, both synthetic and field data examples are presented, demonstrating that the super-virtual refractions generated by our method have accurate traveltimes and much improved SNR.
Fully 3D GPU PET reconstruction
Energy Technology Data Exchange (ETDEWEB)
Herraiz, J.L., E-mail: joaquin@nuclear.fis.ucm.es [Grupo de Fisica Nuclear, Departmento Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Espana, S. [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Cal-Gonzalez, J. [Grupo de Fisica Nuclear, Departmento Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Vaquero, J.J. [Departmento de Bioingenieria e Ingenieria Espacial, Universidad Carlos III, Madrid (Spain); Desco, M. [Departmento de Bioingenieria e Ingenieria Espacial, Universidad Carlos III, Madrid (Spain); Unidad de Medicina y Cirugia Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Udias, J.M. [Grupo de Fisica Nuclear, Departmento Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain)
2011-08-21
Fully 3D iterative tomographic image reconstruction is computationally very demanding. Graphics Processing Unit (GPU) has been proposed for many years as potential accelerators in complex scientific problems, but it has not been used until the recent advances in the programmability of GPUs that the best available reconstruction codes have started to be implemented to be run on GPUs. This work presents a GPU-based fully 3D PET iterative reconstruction software. This new code may reconstruct sinogram data from several commercially available PET scanners. The most important and time-consuming parts of the code, the forward and backward projection operations, are based on an accurate model of the scanner obtained with the Monte Carlo code PeneloPET and they have been massively parallelized on the GPU. For the PET scanners considered, the GPU-based code is more than 70 times faster than a similar code running on a single core of a fast CPU, obtaining in both cases the same images. The code has been designed to be easily adapted to reconstruct sinograms from any other PET scanner, including scanner prototypes.
Fully 3D GPU PET reconstruction
International Nuclear Information System (INIS)
Herraiz, J.L.; Espana, S.; Cal-Gonzalez, J.; Vaquero, J.J.; Desco, M.; Udias, J.M.
2011-01-01
Fully 3D iterative tomographic image reconstruction is computationally very demanding. Graphics Processing Unit (GPU) has been proposed for many years as potential accelerators in complex scientific problems, but it has not been used until the recent advances in the programmability of GPUs that the best available reconstruction codes have started to be implemented to be run on GPUs. This work presents a GPU-based fully 3D PET iterative reconstruction software. This new code may reconstruct sinogram data from several commercially available PET scanners. The most important and time-consuming parts of the code, the forward and backward projection operations, are based on an accurate model of the scanner obtained with the Monte Carlo code PeneloPET and they have been massively parallelized on the GPU. For the PET scanners considered, the GPU-based code is more than 70 times faster than a similar code running on a single core of a fast CPU, obtaining in both cases the same images. The code has been designed to be easily adapted to reconstruct sinograms from any other PET scanner, including scanner prototypes.
3D Printed Dry EEG Electrodes.
Krachunov, Sammy; Casson, Alexander J
2016-10-02
Electroencephalography (EEG) is a procedure that records brain activity in a non-invasive manner. The cost and size of EEG devices has decreased in recent years, facilitating a growing interest in wearable EEG that can be used out-of-the-lab for a wide range of applications, from epilepsy diagnosis, to stroke rehabilitation, to Brain-Computer Interfaces (BCI). A major obstacle for these emerging applications is the wet electrodes, which are used as part of the EEG setup. These electrodes are attached to the human scalp using a conductive gel, which can be uncomfortable to the subject, causes skin irritation, and some gels have poor long-term stability. A solution to this problem is to use dry electrodes, which do not require conductive gel, but tend to have a higher noise floor. This paper presents a novel methodology for the design and manufacture of such dry electrodes. We manufacture the electrodes using low cost desktop 3D printers and off-the-shelf components for the first time. This allows quick and inexpensive electrode manufacturing and opens the possibility of creating electrodes that are customized for each individual user. Our 3D printed electrodes are compared against standard wet electrodes, and the performance of the proposed electrodes is suitable for BCI applications, despite the presence of additional noise.
Directory of Open Access Journals (Sweden)
Sammy Krachunov
2016-10-01
Full Text Available Electroencephalography (EEG is a procedure that records brain activity in a non-invasive manner. The cost and size of EEG devices has decreased in recent years, facilitating a growing interest in wearable EEG that can be used out-of-the-lab for a wide range of applications, from epilepsy diagnosis, to stroke rehabilitation, to Brain-Computer Interfaces (BCI. A major obstacle for these emerging applications is the wet electrodes, which are used as part of the EEG setup. These electrodes are attached to the human scalp using a conductive gel, which can be uncomfortable to the subject, causes skin irritation, and some gels have poor long-term stability. A solution to this problem is to use dry electrodes, which do not require conductive gel, but tend to have a higher noise floor. This paper presents a novel methodology for the design and manufacture of such dry electrodes. We manufacture the electrodes using low cost desktop 3D printers and off-the-shelf components for the first time. This allows quick and inexpensive electrode manufacturing and opens the possibility of creating electrodes that are customized for each individual user. Our 3D printed electrodes are compared against standard wet electrodes, and the performance of the proposed electrodes is suitable for BCI applications, despite the presence of additional noise.
Human perception considerations for 3D content creation
Green, G. Almont
2011-03-01
Observation and interviews with people viewing autostereoscopic 3D imagery provides evidence that there are many human perception considerations required for 3D content creation. A study was undertaken whereby it was witnessed that certain test autostereoscopic imagery elicited a highly emotional response and engagement, while other test autostereoscopic imagery was given only a passing glance. That an image can be viewed with a certain level of stereopsis does not make it compelling. By taking into consideration the manner in which humans perceive depth and the space between objects, 3D content can achieve a level of familiarity and realness that is not possible with single perspective imagery. When human perception issues are ignored, 3D imagery can be undesirable to viewers and a negative bias against 3D imagery can occur. The preparation of 3D content is more important than the display technology. Where human perception, as it is used to interpret reality, is not mimicked in the creation of 3D content, the general public typically express a negative bias against that imagery (where choices are provided). For some, the viewing of 3D content that could not exist naturally, induces physical discomfort.
Bringing 3D Printing to Geophysical Science Education
Boghosian, A.; Turrin, M.; Porter, D. F.
2014-12-01
3D printing technology has been embraced by many technical fields, and is rapidly making its way into peoples' homes and schools. While there is a growing educational and hobbyist community engaged in the STEM focused technical and intellectual challenges associated with 3D printing, there is unrealized potential for the earth science community to use 3D printing to communicate scientific research to the public. Moreover, 3D printing offers scientists the opportunity to connect students and the public with novel visualizations of real data. As opposed to introducing terrestrial measurements through the use of colormaps and gradients, scientists can represent 3D concepts with 3D models, offering a more intuitive education tool. Furthermore, the tactile aspect of models make geophysical concepts accessible to a wide range of learning styles like kinesthetic or tactile, and learners including both visually impaired and color-blind students.We present a workflow whereby scientists, students, and the general public will be able to 3D print their own versions of geophysical datasets, even adding time through layering to include a 4th dimension, for a "4D" print. This will enable scientists with unique and expert insights into the data to easily create the tools they need to communicate their research. It will allow educators to quickly produce teaching aids for their students. Most importantly, it will enable the students themselves to translate the 2D representation of geophysical data into a 3D representation of that same data, reinforcing spatial reasoning.
3D Printing device adaptable to Computer Numerical Control (CNC)
GARDAN , Julien; Danesi , F.; Roucoules , Lionel; Schneider , A.
2014-01-01
This article presents the development of a 3D printing device for the additive manufacturing adapted to a CNC machining. The application involves the integration of a specific printing head. Additive manufacturing technology is most commonly used for modeling, prototyping, tooling through an exclusive machine or 3D printer. A global review and analysis of technologies show the additive manufacturing presents little independent solutions [6][9]. The problem studied especially the additive manu...
Will 3D printers manufacture your meals?
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.
Eesti 3D jaoks kitsas / Virge Haavasalu
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
Moussawi, Ali; Lubineau, Gilles; Xu, Jiangping; Pan, Bing
2015-01-01
Summary: The post-treatment of (3D) displacement fields for the identification of spatially varying elastic material parameters is a large inverse problem that remains out of reach for massive 3D structures. We explore here the potential
Multimodal Sensor-Based Semantic 3D Mapping for a Large-Scale Environment
Jeong, Jongmin; Yoon, Tae Sung; Park, Jin Bae
2018-01-01
Semantic 3D mapping is one of the most important fields in robotics, and has been used in many applications, such as robot navigation, surveillance, and virtual reality. In general, semantic 3D mapping is mainly composed of 3D reconstruction and semantic segmentation. As these technologies evolve, there has been great progress in semantic 3D mapping in recent years. Furthermore, the number of robotic applications requiring semantic information in 3D mapping to perform high-level tasks has inc...
3D-Printed Millimeter Wave Structures
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
Digital Dentistry — 3D Printing Applications
Zaharia Cristian; Gabor Alin-Gabriel; Gavrilovici Andrei; Stan Adrian Tudor; Idorasi Laura; Sinescu Cosmin; Negruțiu Meda-Lavinia
2017-01-01
Three-dimensional (3D) printing is an additive manufacturing method in which a 3D item is formed by laying down successive layers of material. 3D printers are machines that produce representations of objects either planned with a CAD program or scanned with a 3D scanner. Printing is a method for replicating text and pictures, typically with ink on paper. We can print different dental pieces using different methods such as selective laser sintering (SLS), stereolithography, fused deposition mo...
Detectors in 3D available for assessment
Re, Valerio
2014-01-01
This deliverable reports on 3D devices resulting from the vertical integration of pixel sensors and readout electronics. After 3D integration steps such as etching of through-silicon vias and backside metallization of readout integrated circuits, ASICs and sensors are interconnected to form a 3D pixel detector. Various 3D detectors have been devised in AIDA WP3 and their status and performance is assessed here.
Energy Technology Data Exchange (ETDEWEB)
Ratz, V.; Wech, T.; Schindele, A.; Dierks, A.; Sauer, A.; Reibetanz, J.; Borzi, A.; Bley, T.; Koestler, H.
2016-09-15
Epidemiological studies have estimated the incidence of chronic constipation to be up to 27% of the general population. The gold standard to evaluate affected patients is the dynamic entero-colpo-cysto-defecography. In the clinical routine 2 D MR-defecography is also performed, but only one to three 2 D slices at a temporal footprint of about one second are acquired. To improve the detection of lateral localized pathologies, we developed and implemented dynamic 3 D MR-defecography. Each 3 D block consisted of seven slices with an in-plane spatial resolution of 1.3 x 1.3 mm{sup 2} to 2.3 x 2.3 mm{sup 2} and an image update rate between 0.8 s and 1.3 s. We used a fast bSSFP sequence with a modified stack-of-stars sampling scheme for data acquisition and a modified FISTA compressed sensing algorithm to reconstruct the undersampled datasets. We performed a study including 6 patients to optimize the acquisition parameters with respect to image quality.
International Nuclear Information System (INIS)
Ratz, V.; Wech, T.; Schindele, A.; Dierks, A.; Sauer, A.; Reibetanz, J.; Borzi, A.; Bley, T.; Koestler, H.
2016-01-01
Epidemiological studies have estimated the incidence of chronic constipation to be up to 27% of the general population. The gold standard to evaluate affected patients is the dynamic entero-colpo-cysto-defecography. In the clinical routine 2 D MR-defecography is also performed, but only one to three 2 D slices at a temporal footprint of about one second are acquired. To improve the detection of lateral localized pathologies, we developed and implemented dynamic 3 D MR-defecography. Each 3 D block consisted of seven slices with an in-plane spatial resolution of 1.3 x 1.3 mm 2 to 2.3 x 2.3 mm 2 and an image update rate between 0.8 s and 1.3 s. We used a fast bSSFP sequence with a modified stack-of-stars sampling scheme for data acquisition and a modified FISTA compressed sensing algorithm to reconstruct the undersampled datasets. We performed a study including 6 patients to optimize the acquisition parameters with respect to image quality.
On a covariant 2+2 formulation of the initial value problem in general relativity
International Nuclear Information System (INIS)
Smallwood, J.
1980-03-01
The initial value problems in general relativity are considered from a geometrical standpoint with especial reference to the development of a covariant 2+2 formalism in which space-time is foliated by space-like 2-surfaces under the headings; the Cauchy problem in general relativity, the covariant 3+1 formulation of the Cauchy problem, characteristic and mixed initial value problems, on locally imbedding a family of null hypersurfaces, the 2+2 formalism, the 2+2 formulation of the Cauchy problem, the 2+2 formulation of the characteristic and mixed initial value problems, and a covariant Lagrangian 2+2 formulation. (U.K.)
Directory of Open Access Journals (Sweden)
Vahid Dadashi
2016-02-01
Full Text Available Abstract This paper is dedicated to the introduction a new class of equilibrium problems named generalized multivalued equilibrium-like problems which includes the classes of hemiequilibrium problems, equilibrium-like problems, equilibrium problems, hemivariational inequalities, and variational inequalities as special cases. By utilizing the auxiliary principle technique, some new predictor-corrector iterative algorithms for solving them are suggested and analyzed. The convergence analysis of the proposed iterative methods requires either partially relaxed monotonicity or jointly pseudomonotonicity of the bifunctions involved in generalized multivalued equilibrium-like problem. Results obtained in this paper include several new and known results as special cases.
Energy Technology Data Exchange (ETDEWEB)
Meissner, K. [Institut fuer Automatisierung und Informatik GmbH, Zentrum fuer industrielle Forschung und Entwicklung, Wernigerode (Germany); Hensel, H. [Hochschule Harz, Fachbereich Automatisierung und Informatik, Wernigerode (Germany)
2007-07-01
The current technological progress in the process industry results in a significant increase of the complexity of control systems. The amount of supervised information grows constantly for each operator because of a higher level of automation and an optimized information acquisition of the control systems. This development results in a cognitive overload of the operator which causes incorrect behaviour and responses in alert situations. In technical literature, several approaches are discussed to counteract this problem. This paper presents the newly developed 3-D Process Information Display (3D-PID) and describes which additional application areas as a primary representation method to the supervision of complex process conditions are imaginable. The 3D-PID is based on a cognitive scenic representation of the process values within a 3-D process room. Particularly the problem of the overview and detail presentation known from the literature is discussed. (orig.)
General solution to the E-B mixing problem
International Nuclear Information System (INIS)
Smith, Kendrick M.; Zaldarriaga, Matias
2007-01-01
We derive a general ansatz for optimizing pseudo-C l estimators used to measure cosmic microwave background anisotropy power spectra, and apply it to the recently proposed pure pseudo-C l formalism, to obtain an estimator which achieves near-optimal B-mode power spectrum errors for any specified noise distribution while minimizing leakage from ambiguous modes. Our technique should be relevant for upcoming cosmic microwave background polarization experiments searching for B-mode polarization. We compare our technique both to the theoretical limits based on a full Fisher matrix calculation and to the standard pseudo-C l technique. We demonstrate it by applying it to a fiducial survey with realistic inhomogeneous noise, complex boundaries, point source masking, and a noise level comparable to what is expected for next-generation experiments (∼5.75 μK-arcmin). For such an experiment our technique could improve the constraints on the amplitude of a gravity wave background by over a factor of 10 compared to what could be obtained using ordinary pseudo-C l , coming quite close to saturating the theoretical limit. Constraints on the amplitude of the lensing B-modes are improved by about a factor of 3
Generalized information theory: aims, results, and open problems
International Nuclear Information System (INIS)
Klir, George J.
2004-01-01
The principal purpose of this paper is to present a comprehensive overview of generalized information theory (GIT): a research program whose objective is to develop a broad treatment of uncertainty-based information, not restricted to classical notions of uncertainty. After a brief overview of classical information theories, a broad framework for formalizing uncertainty and the associated uncertainty-based information of a great spectrum of conceivable types is sketched. The various theories of imprecise probabilities that have already been developed within this framework are then surveyed, focusing primarily on some important unifying principles applying to all these theories. This is followed by introducing two higher levels of the theories of imprecise probabilities: (i) the level of measuring the amount of relevant uncertainty (predictive, retrodictive, prescriptive, diagnostic, etc.) in any situation formalizable in each given theory, and (ii) the level of some methodological principles of uncertainty, which are contingent upon the capability to measure uncertainty and the associated uncertainty-based information. Various issues regarding both the measurement of uncertainty and the uncertainty principles are discussed. Again, the focus is on unifying principles applicable to all the theories. Finally, the current status of GIT is assessed and future research in the area is discussed
3D modelling for multipurpose cadastre
Abduhl Rahman, A.; Van Oosterom, P.J.M.; Hua, T.C.; Sharkawi, K.H.; Duncan, E.E.; Azri, N.; Hassan, M.I.
2012-01-01
Three-dimensional (3D) modelling of cadastral objects (such as legal spaces around buildings, around utility networks and other spaces) is one of the important aspects for a multipurpose cadastre (MPC). This paper describes the 3D modelling of the objects for MPC and its usage to the knowledge of 3D
Expanding Geometry Understanding with 3D Printing
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…
3D Characterization of Recrystallization Boundaries
DEFF Research Database (Denmark)
Zhang, Yubin; Godfrey, Andrew William; MacDonald, A. Nicole
2016-01-01
A three-dimensional (3D) volume containing a recrystallizing grain and a deformed matrix in a partially recrystallized pure aluminum was characterized using the 3D electron backscattering diffraction technique. The 3D shape of a recrystallizing boundary, separating the recrystallizing grain...... on the formation of protrusions/retrusions....
Slope instability in complex 3D topography promoted by convergent 3D groundwater flow
Reid, M. E.; Brien, D. L.
2012-12-01
Slope instability in complex topography is generally controlled by the interaction between gravitationally induced stresses, 3D strengths, and 3D pore-fluid pressure fields produced by flowing groundwater. As an example of this complexity, coastal bluffs sculpted by landsliding commonly exhibit a progression of undulating headlands and re-entrants. In this landscape, stresses differ between headlands and re-entrants and 3D groundwater flow varies from vertical rainfall infiltration to lateral groundwater flow on lower permeability layers with subsequent discharge at the curved bluff faces. In plan view, groundwater flow converges in the re-entrant regions. To investigate relative slope instability induced by undulating topography, we couple the USGS 3D limit-equilibrium slope-stability model, SCOOPS, with the USGS 3D groundwater flow model, MODFLOW. By rapidly analyzing the stability of millions of potential failures, the SCOOPS model can determine relative slope stability throughout the 3D domain underlying a digital elevation model (DEM), and it can utilize both fully 3D distributions of pore-water pressure and material strength. The two models are linked by first computing a groundwater-flow field in MODFLOW, and then computing stability in SCOOPS using the pore-pressure field derived from groundwater flow. Using these two models, our analyses of 60m high coastal bluffs in Seattle, Washington showed augmented instability in topographic re-entrants given recharge from a rainy season. Here, increased recharge led to elevated perched water tables with enhanced effects in the re-entrants owing to convergence of groundwater flow. Stability in these areas was reduced about 80% compared to equivalent dry conditions. To further isolate these effects, we examined groundwater flow and stability in hypothetical landscapes composed of uniform and equally spaced, oscillating headlands and re-entrants with differing amplitudes. The landscapes had a constant slope for both
ACTUAL PERFORMANCE 3D RESTRICTIONS OF INVENTOR 2015
Directory of Open Access Journals (Sweden)
GOANȚĂ Adrian Mihai
2015-06-01
Full Text Available The work ranges between papers that leave detailed documentation based on the analysis of current performance 3D constraints, the Autodesk Inventor 2015 and draws a number of conclusions in general about this latest software. Basically, the author, after a presentation of the current situation and trends and future aided design, makes an analysis of how 3D constraint of the three-dimensional assemblies. Also some of the innovations introduced by this version are highlighted.
3D-CT angiography. Intracranial arterial lesions
Energy Technology Data Exchange (ETDEWEB)
Asato, Mikio; Tong, X.Q.; Tamura, Shozo [Miyazaki Medical Coll., Kiyotake (Japan)] [and others
1997-06-01
Since its introduction, three dimensional CT angiography (3D-CTA) on spiral (helical) CT has played an important role in clinical imaging. Initially it was reported to be useful in depicting aortic abnormalities, afterwards the merit in detecting intracranial aneurysm by 3D-CTA was also described. We have investigated the usefullness of 3D-CTA in detecting patients of intracranial aneurysm as well as arterio-venous malformation (AVM), Moyamoya disease and stenosis of middle cerebral artery, meanwhile the MR angiography (MRA) and digital subtraction angiography (DSA) examination of these patients were also studied as comparison to the 3D-CTA results. The sensitivity and specificity on investigating intracranial aneurysm were similar with other reports so far. 3D-CTA was possible to identify the feeding artery, nidus and draining vein of AVM, although DSA showed higher detectability. Occlusion of internal carotid artery and post-operative anastomosis in Moyamoya disease were all demonstrated by 3D-CTA, however the Moyamoya collaterals were shown better on MRA. 3D-CTA revealed the site of stenosis of middle cerebral artery in all of our cases, but in general maximum intensity projection (MIP) images can provide more exact information about the degree of stenosis. Five years has passed since the emergence of spiral CT and utilizing of 3D-CTA in clinical applications. With the development of hard and soft ware in the near future, it is possible to delineate more small vessels by 3D-CTA. We predict that 3D-CTA would be widely used for detecting vasculature of the whole body, and may take the place of conventional angiography in many cases. (author)
Quality assurance for 3D conformal radiation therapy
International Nuclear Information System (INIS)
Purdy, J.A.; Harms, W.B.
1998-01-01
Three-dimensional conformal radiation therapy (3D CRT) can be considered as an integrated process of treatment planning, delivery, and verification that attempts to conform the prescription dose closely to the target volume while limiting dose to critical normal structures. Requiring the prescription dose to conform as closely as possible to the target volume raises the level of the precision and accuracy requirements generally found in conventional radiation therapy. 3D CRT treatment planning requires robust patient immobilization/repositioning systems and volumetric image data (CT and/or MR) acquired in the treatment position. 3D treatment planning more explicitly details the particular of a patient's treatment than was ever possible with 2D treatment planning. In 1992, we implemented a formal 3D treatment planning service in our clinic and at the same time instituted a formal quality assurance (QA) program addressing the individual procedures that make up the 3D CRT process. Our 3D QA program includes systematic testing of the hardware and software used in the 3D treatment planning process, careful review of each patient's treatment plan, careful review of the physical implementation of the treatment plan, a peer review 3D QA Case Conference, and a formal continuing education program in 3D CRT for our radiation therapy staff. This broad 3D QA program requires the involvement of physicians, physicists, dosimetrists, and the treating radiation therapists that complete the team responsible for 3D CRT.3D CRT capabilities change the kinds of radiation therapy treatments that are possible and that changes the process with which treatment planning and treatment delivery are performed. There is no question that 3D CRT shows significant potential for improving the quality of radiation therapy and improving the efficiency with which it can be delivered. However, its implementation and wide spread use is still in its initial stages. The techniques used for 3D treatment
View-based 3-D object retrieval
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
Wafer level 3-D ICs process technology
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.
Case study: Beauty and the Beast 3D: benefits of 3D viewing for 2D to 3D conversion
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.
Construction of programmable interconnected 3D microfluidic networks
International Nuclear Information System (INIS)
Hunziker, Patrick R; Wolf, Marc P; Wang, Xueya; Zhang, Bei; Marsch, Stephan; Salieb-Beugelaar, Georgette B
2015-01-01
Microfluidic systems represent a key-enabling platform for novel diagnostic tools for use at the point-of-care in clinical contexts as well as for evolving single cell diagnostics. The design of 3D microfluidic systems is an active field of development, but construction of true interconnected 3D microfluidic networks is still a challenge, in particular when the goal is rapid prototyping, accurate design and flexibility. We report a novel approach for the construction of programmable 3D microfluidic systems consisting of modular 3D template casting of interconnected threads to allow user-programmable flow paths and examine its structural characteristics and its modular function. To overcome problems with thread template casting reported in the literature, low-surface-energy polymer threads were used, that allow solvent-free production. Connected circular channels with excellent roundness and low diameter variability were created. Variable channel termination allowed programming a flow path on-the-fly, thus rendering the resulting 3D microfluidic systems highly customizable even after production. Thus, construction of programmable/reprogrammable fully 3D microfluidic systems by template casting of a network of interconnecting threads is feasible, leads to high-quality and highly reproducible, complex 3D geometries. (paper)
Ekici, Didem Inel
2016-01-01
This study aimed to determine Turkish junior high-school students' perceptions of the general problem-solving process. The Turkish junior high-school students' perceptions of the general problem-solving process were examined in relation to their gender, grade level, age and their grade point with regards to the science course identified in the…
3DSEM: A 3D microscopy dataset
Directory of Open Access Journals (Sweden)
Ahmad P. Tafti
2016-03-01
Full Text Available The Scanning Electron Microscope (SEM as a 2D imaging instrument has been widely used in many scientific disciplines including biological, mechanical, and materials sciences to determine the surface attributes of microscopic objects. However the SEM micrographs still remain 2D images. To effectively measure and visualize the surface properties, we need to truly restore the 3D shape model from 2D SEM images. Having 3D surfaces would provide anatomic shape of micro-samples which allows for quantitative measurements and informative visualization of the specimens being investigated. The 3DSEM is a dataset for 3D microscopy vision which is freely available at [1] for any academic, educational, and research purposes. The dataset includes both 2D images and 3D reconstructed surfaces of several real microscopic samples. Keywords: 3D microscopy dataset, 3D microscopy vision, 3D SEM surface reconstruction, Scanning Electron Microscope (SEM
Rendering Large-Scale Terrain Models and Positioning Objects in Relation to 3D Terrain
National Research Council Canada - National Science Library
Hittner, Brian
2003-01-01
.... Rendering large scale landscapes based on 3D geometry generally did not occur because the scenes generated tended to use up too much system memory and overburden 3D graphics cards with too many polygons...
3D vision in a virtual reality robotics environment
Schutz, Christian L.; Natonek, Emerico; Baur, Charles; Hugli, Heinz
1996-12-01
Virtual reality robotics (VRR) needs sensing feedback from the real environment. To show how advanced 3D vision provides new perspectives to fulfill these needs, this paper presents an architecture and system that integrates hybrid 3D vision and VRR and reports about experiments and results. The first section discusses the advantages of virtual reality in robotics, the potential of a 3D vision system in VRR and the contribution of a knowledge database, robust control and the combination of intensity and range imaging to build such a system. Section two presents the different modules of a hybrid 3D vision architecture based on hypothesis generation and verification. Section three addresses the problem of the recognition of complex, free- form 3D objects and shows how and why the newer approaches based on geometric matching solve the problem. This free- form matching can be efficiently integrated in a VRR system as a hypothesis generation knowledge-based 3D vision system. In the fourth part, we introduce the hypothesis verification based on intensity images which checks object pose and texture. Finally, we show how this system has been implemented and operates in a practical VRR environment used for an assembly task.
de Kleijn, Bertram J; Kraeima, Joep; Wachters, Jasper E; van der Laan, Bernard F A M; Wedman, Jan; Witjes, M J H; Halmos, Gyorgy B
2018-02-01
We aimed to investigate the potential of 3D virtual planning of tracheostomy tube placement and 3D cannula design to prevent tracheostomy complications due to inadequate cannula position. 3D models of commercially available cannula were positioned in 3D models of the airway. In study (1), a cohort that underwent tracheostomy between 2013 and 2015 was selected (n = 26). The cannula was virtually placed in the airway in the pre-operative CT scan and its position was compared to the cannula position on post-operative CT scans. In study (2), a cohort with neuromuscular disease (n = 14) was analyzed. Virtual cannula placing was performed in CT scans and tested if problems could be anticipated. Finally (3), for a patient with Duchenne muscular dystrophy and complications of conventional tracheostomy cannula, a patient-specific cannula was 3D designed, fabricated, and placed. (1) The 3D planned and post-operative tracheostomy position differed significantly. (2) Three groups of patients were identified: (A) normal anatomy; (B) abnormal anatomy, commercially available cannula fits; and (C) abnormal anatomy, custom-made cannula, may be necessary. (3) The position of the custom-designed cannula was optimal and the trachea healed. Virtual planning of the tracheostomy did not correlate with actual cannula position. Identifying patients with abnormal airway anatomy in whom commercially available cannula cannot be optimally positioned is advantageous. Patient-specific cannula design based on 3D virtualization of the airway was beneficial in a patient with abnormal airway anatomy.
Directory of Open Access Journals (Sweden)
Phayap Katchang
2010-01-01
Full Text Available The purpose of this paper is to investigate the problem of finding a common element of the set of solutions for mixed equilibrium problems, the set of solutions of the variational inclusions with set-valued maximal monotone mappings and inverse-strongly monotone mappings, and the set of fixed points of a family of finitely nonexpansive mappings in the setting of Hilbert spaces. We propose a new iterative scheme for finding the common element of the above three sets. Our results improve and extend the corresponding results of the works by Zhang et al. (2008, Peng et al. (2008, Peng and Yao (2009, as well as Plubtieng and Sriprad (2009 and some well-known results in the literature.
3D electrical conductivity tomography of volcanoes
Soueid Ahmed, A.; Revil, A.; Byrdina, S.; Coperey, A.; Gailler, L.; Grobbe, N.; Viveiros, F.; Silva, C.; Jougnot, D.; Ghorbani, A.; Hogg, C.; Kiyan, D.; Rath, V.; Heap, M. J.; Grandis, H.; Humaida, H.
2018-05-01
Electrical conductivity tomography is a well-established galvanometric method for imaging the subsurface electrical conductivity distribution. We characterize the conductivity distribution of a set of volcanic structures that are different in terms of activity and morphology. For that purpose, we developed a large-scale inversion code named ECT-3D aimed at handling complex topographical effects like those encountered in volcanic areas. In addition, ECT-3D offers the possibility of using as input data the two components of the electrical field recorded at independent stations. Without prior information, a Gauss-Newton method with roughness constraints is used to solve the inverse problem. The roughening operator used to impose constraints is computed on unstructured tetrahedral elements to map complex geometries. We first benchmark ECT-3D on two synthetic tests. A first test using the topography of Mt. St Helens volcano (Washington, USA) demonstrates that we can successfully reconstruct the electrical conductivity field of an edifice marked by a strong topography and strong variations in the resistivity distribution. A second case study is used to demonstrate the versatility of the code in using the two components of the electrical field recorded on independent stations along the ground surface. Then, we apply our code to real data sets recorded at (i) a thermally active area of Yellowstone caldera (Wyoming, USA), (ii) a monogenetic dome on Furnas volcano (the Azores, Portugal), and (iii) the upper portion of the caldera of Kīlauea (Hawai'i, USA). The tomographies reveal some of the major structures of these volcanoes as well as identifying alteration associated with high surface conductivities. We also review the petrophysics underlying the interpretation of the electrical conductivity of fresh and altered volcanic rocks and molten rocks to show that electrical conductivity tomography cannot be used as a stand-alone technique due to the non-uniqueness in
Image based 3D city modeling : Comparative study
Directory of Open Access Journals (Sweden)
S. P. Singh
2014-06-01
Full Text Available 3D city model is a digital representation of the Earth’s surface and it’s related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India. This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can’t do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good
Virtual 3d City Modeling: Techniques and Applications
Singh, S. P.; Jain, K.; Mandla, V. R.
2013-08-01
3D city model is a digital representation of the Earth's surface and it's related objects such as Building, Tree, Vegetation, and some manmade feature belonging to urban area. There are various terms used for 3D city models such as "Cybertown", "Cybercity", "Virtual City", or "Digital City". 3D city models are basically a computerized or digital model of a city contains the graphic representation of buildings and other objects in 2.5 or 3D. Generally three main Geomatics approach are using for Virtual 3-D City models generation, in first approach, researcher are using Conventional techniques such as Vector Map data, DEM, Aerial images, second approach are based on High resolution satellite images with LASER scanning, In third method, many researcher are using Terrestrial images by using Close Range Photogrammetry with DSM & Texture mapping. We start this paper from the introduction of various Geomatics techniques for 3D City modeling. These techniques divided in to two main categories: one is based on Automation (Automatic, Semi-automatic and Manual methods), and another is Based on Data input techniques (one is Photogrammetry, another is Laser Techniques). After details study of this, finally in short, we are trying to give the conclusions of this study. In the last, we are trying to give the conclusions of this research paper and also giving a short view for justification and analysis, and present trend for 3D City modeling. This paper gives an overview about the Techniques related with "Generation of Virtual 3-D City models using Geomatics Techniques" and the Applications of Virtual 3D City models. Photogrammetry, (Close range, Aerial, Satellite), Lasergrammetry, GPS, or combination of these modern Geomatics techniques play a major role to create a virtual 3-D City model. Each and every techniques and method has some advantages and some drawbacks. Point cloud model is a modern trend for virtual 3-D city model. Photo-realistic, Scalable, Geo-referenced virtual 3
Advanced quadratures and periodic boundary conditions in parallel 3D Sn transport
International Nuclear Information System (INIS)
Manalo, K.; Yi, C.; Huang, M.; Sjoden, G.
2013-01-01
Significant updates in numerical quadratures have warranted investigation with 3D Sn discrete ordinates transport. We show new applications of quadrature departing from level symmetric ( 2 o) and Pn-Tn (>S 2 o). investigating 3 recently developed quadratures: Even-Odd (EO), Linear-Discontinuous Finite Element - Surface Area (LDFE-SA), and the non-symmetric Icosahedral Quadrature (IC). We discuss implementation changes to 3D Sn codes (applied to Hybrid MOC-Sn TITAN and 3D parallel PENTRAN) that can be performed to accommodate Icosahedral Quadrature, as this quadrature is not 90-degree rotation invariant. In particular, as demonstrated using PENTRAN, the properties of Icosahedral Quadrature are suitable for trivial application using periodic BCs versus that of reflective BCs. In addition to implementing periodic BCs for 3D Sn PENTRAN, we implemented a technique termed 'angular re-sweep' which properly conditions periodic BCs for outer eigenvalue iterative loop convergence. As demonstrated by two simple transport problems (3-group fixed source and 3-group reflected/periodic eigenvalue pin cell), we remark that all of the quadratures we investigated are generally superior to level symmetric quadrature, with Icosahedral Quadrature performing the most efficiently for problems tested. (authors)
Attila calculations for the 3-D C5G7 benchmark extension
International Nuclear Information System (INIS)
Wareing, T.A.; McGhee, J.M.; Barnett, D.A.; Failla, G.A.
2005-01-01
The performance of the Attila radiation transport software was evaluated for the 3-D C5G7 MOX benchmark extension, a follow-on study to the MOX benchmark developed by the 'OECD/NEA Expert Group on 3-D Radiation Transport Benchmarks'. These benchmarks were designed to test the ability of modern deterministic transport methods to model reactor problems without spatial homogenization. Attila is a general purpose radiation transport software package with an integrated graphical user interface (GUI) for analysis, set-up and postprocessing. Attila provides solutions to the discrete-ordinates form of the linear Boltzmann transport equation on a fully unstructured, tetrahedral mesh using linear discontinuous finite-element spatial differencing in conjunction with diffusion synthetic acceleration of inner iterations. The results obtained indicate that Attila can accurately solve the benchmark problem without spatial homogenization. (authors)
Repetto, P.; Martínez-García, E. E.; Rosado, M.; Gabbasov, R.
2018-06-01
In this paper, we derive a novel circular velocity relation for a test particle in a 3D gravitational potential applicable to every system of curvilinear coordinates, suitable to be reduced to orthogonal form. As an illustration of the potentiality of the determined circular velocity expression, we perform the rotation curves analysis of UGC 8490 and UGC 9753 and we estimate the total and dark matter mass of these two galaxies under the assumption that their respective dark matter haloes have spherical, prolate, and oblate spheroidal mass distributions. We employ stellar population synthesis models and the total H I density map to obtain the stellar and H I+He+metals rotation curves of both galaxies. The subtraction of the stellar plus gas rotation curves from the observed rotation curves of UGC 8490 and UGC 9753 generates the dark matter circular velocity curves of both galaxies. We fit the dark matter rotation curves of UGC 8490 and UGC 9753 through the newly established circular velocity formula specialized to the spherical, prolate, and oblate spheroidal mass distributions, considering the Navarro, Frenk, and White, Burkert, Di Cintio, Einasto, and Stadel dark matter haloes. Our principal findings are the following: globally, cored dark matter profiles Burkert and Einasto prevail over cuspy Navarro, Frenk, and White, and Di Cintio. Also, spherical/oblate dark matter models fit better the dark matter rotation curves of both galaxies than prolate dark matter haloes.
International Nuclear Information System (INIS)
Loubere, Raphael; Maire, Pierre-Henri; Vachal, Pavel
2013-01-01
The aim of the present work is the 3D extension of a general formalism to derive a staggered discretization for Lagrangian hydrodynamics on unstructured grids. The classical compatible discretization is used; namely, momentum equation is discretized using the fundamental concept of subcell forces. Specific internal energy equation is obtained using total energy conservation. The subcell force is derived by invoking the Galilean invariance and thermodynamic consistency. A general form of the subcell force is provided so that a cell entropy inequality is satisfied. The subcell force consists of a classical pressure term plus a tensorial viscous contribution proportional to the difference between the node velocity and the cell-centered velocity. This cell-centered velocity is an extra degree of freedom solved with a cell-centered approximate Riemann solver. The second law of thermodynamics is satisfied by construction of the local positive definite subcell tensor involved in the viscous term. A particular expression of this tensor is proposed. A more accurate extension of this discretization both in time and space is also provided using a piecewise linear reconstruction of the velocity field and a predictor-corrector time discretization. Numerical tests are presented in order to assess the efficiency of this approach in 3D. Sanity checks show that the 3D extension of the 2D approach reproduces 1D and 2D results. Finally, 3D problems such as Sedov, Noh, and Saltzman are simulated. (authors)
Critical bifurcation surfaces of 3D discrete dynamics
Directory of Open Access Journals (Sweden)
Michael Sonis
2000-01-01
Full Text Available This paper deals with the analytical representation of bifurcations of each 3D discrete dynamics depending on the set of bifurcation parameters. The procedure of bifurcation analysis proposed in this paper represents the 3D elaboration and specification of the general algorithm of the n-dimensional linear bifurcation analysis proposed by the author earlier. It is proven that 3D domain of asymptotic stability (attraction of the fixed point for a given 3D discrete dynamics is bounded by three critical bifurcation surfaces: the divergence, flip and flutter surfaces. The analytical construction of these surfaces is achieved with the help of classical Routh–Hurvitz conditions of asymptotic stability. As an application the adjustment process proposed by T. Puu for the Cournot oligopoly model is considered in detail.
Simulation analysis of turbine blade in 3D printing aquarium
Directory of Open Access Journals (Sweden)
Chen Dyi-Cheng
2017-01-01
Full Text Available 3D printing of the flexibility is the most admirable place, no matter when or where, as long as the machine can make the abstract design of finished products or difficult to process the finished product printed out as a sample. And in the product design, through the 3D print out the entity, to more specific observation of the advantages and disadvantages of finished products, which shorten the time of many creative research and development, but also relatively reduce the defective factors. As in recent years, 3D printing technology is progressing, material adhesion, precision and parts of the degree of cooperation has increased, coupled with many parts taking into account the cost, production and other issues, and then let a lot of light load small parts or special parts choose to use 3D to print the finished product to replace. This study focuses on the plastic turbine blades that drive water in the aquarium, but the 3D printing is done by stacking. However, the general stress analysis software can set the material to analyze the deformation results of the force, nor the 3D to analyze the software. Therefore, this study first analyzes the deformation of turbine blade by software, and then verifies the situation of 3D printing turbine blade, and then compares the actual results of software analysis and 3D printing. The results can provide the future of 3D product consider the strength factor. The study found that the spiral blade design allows the force points to be dispersed to avoid hard focus.
International Nuclear Information System (INIS)
Olivieri, E.; Scoppola, E.
1996-01-01
In this paper we consider aperiodic ergodic Markov chains with transition probabilities exponentially small in a large parameter β. We extend to the general, not necessarily reversible case the analysis, started in part I of this work, of the first exit problem from a general domain Q containing many stable equilibria (attracting equilibrium points for the β = ∞ dynamics). In particular we describe the tube of typical trajectories during the first excursion outside Q
FROMS3D: New Software for 3-D Visualization of Fracture Network System in Fractured Rock Masses
Noh, Y. H.; Um, J. G.; Choi, Y.
2014-12-01
A new software (FROMS3D) is presented to visualize fracture network system in 3-D. The software consists of several modules that play roles in management of borehole and field fracture data, fracture network modelling, visualization of fracture geometry in 3-D and calculation and visualization of intersections and equivalent pipes between fractures. Intel Parallel Studio XE 2013, Visual Studio.NET 2010 and the open source VTK library were utilized as development tools to efficiently implement the modules and the graphical user interface of the software. The results have suggested that the developed software is effective in visualizing 3-D fracture network system, and can provide useful information to tackle the engineering geological problems related to strength, deformability and hydraulic behaviors of the fractured rock masses.
Case report of asthma associated with 3D printing.
House, R; Rajaram, N; Tarlo, S M
2017-12-02
Three-dimensional (3D) printing is being increasingly used in manufacturing and by small business entrepreneurs and home hobbyists. Exposure to airborne emissions during 3D printing raises the issue of whether there may be adverse health effects associated with these emissions. We present a case of a worker who developed asthma while using 3D printers, which illustrates that respiratory problems may be associated with 3D printer emissions. The patient was a 28-year-old self-employed businessman with a past history of asthma in childhood, which had resolved completely by the age of eight. He started using 10 fused deposition modelling 3D printers with acrylonitrile-butadiene-styrene filaments in a small work area of approximately 3000 cubic feet. Ten days later, he began to experience recurrent chest tightness, shortness of breath and coughing at work. After 3 months, his work environment was modified by reducing the number of printers, changing to polylactic acid filaments and using an air purifier with an high-efficiency particulate air filter and organic cartridge. His symptoms improved gradually, although he still needed periodic treatment with a salbutamol inhaler. While still symptomatic, a methacholine challenge indicated a provocation concentration causing a 20% fall in FEV1 (PC20) of 4 mg/ml, consistent with mild asthma. Eventually, his symptoms resolved completely and a second methacholine challenge after symptom resolution was normal (PC20 > 16 mg/ml). This case indicates that workers may develop respiratory problems, including asthma when using 3D printers. Further investigation of the specific airborne emissions and health problems from 3D printing is warranted. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com
Identification of the transition arrays 3d74s-3d74p in Br X and 3d64s-3d64p in Br XI
International Nuclear Information System (INIS)
Zeng, X.T.; Jupen, C.; Bengtsson, P.; Engstroem, L.; Westerlind, M.; Martinson, I.
1991-01-01
We report a beam-foil study of multiply ionized bromine in the region 400-1300A, performed with 6 and 8 MeV Br ions from a tandem accelerator. At these energies transitions belonging to Fe-like Br X and Mn-like Br XI are expected to be prominent. We have identified 31 lines as 3d 7 4s-3d 7 4p transitions in Br X, from which 16 levels of the previously unknown 3d 7 4s configuration could be established. We have also added 6 new 3d 7 4p levels to the 99 previously known. For Br XI we have classified 9 lines as 3d 6 4s-3d 6 4p combinations. The line identifications have been corroborated by isoelectronic comparisons and theoretical calculations using the superposition-of-configurations technique. (orig.)
3D PHOTOGRAPHS IN CULTURAL HERITAGE
Directory of Open Access Journals (Sweden)
W. Schuhr
2013-07-01
Full Text Available This paper on providing "oo-information" (= objective object-information on cultural monuments and sites, based on 3D photographs is also a contribution of CIPA task group 3 to the 2013 CIPA Symposium in Strasbourg. To stimulate the interest in 3D photography for scientists as well as for amateurs, 3D-Masterpieces are presented. Exemplary it is shown, due to their high documentary value ("near reality", 3D photography support, e.g. the recording, the visualization, the interpretation, the preservation and the restoration of architectural and archaeological objects. This also includes samples for excavation documentation, 3D coordinate calculation, 3D photographs applied for virtual museum purposes and as educational tools. In addition 3D photography is used for virtual museum purposes, as well as an educational tool and for spatial structure enhancement, which in particular holds for inscriptions and in rock arts. This paper is also an invitation to participate in a systematic survey on existing international archives of 3D photographs. In this respect it is also reported on first results, to define an optimum digitization rate for analog stereo views. It is more than overdue, in addition to the access to international archives for 3D photography, the available 3D photography data should appear in a global GIS(cloud-system, like on, e.g., google earth. This contribution also deals with exposing new 3D photographs to document monuments of importance for Cultural Heritage, including the use of 3D and single lense cameras from a 10m telescope staff, to be used for extremely low earth based airborne 3D photography, as well as for "underwater staff photography". In addition it is reported on the use of captive balloon and drone platforms for 3D photography in Cultural Heritage. It is liked to emphasize, the still underestimated 3D effect on real objects even allows, e.g., the spatial perception of extremely small scratches as well as of nuances in
3D Systems” ‘Stuck in the Middle’ of the 3D Printer Boom?
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
3D Scientific Visualization with Blender
Kent, Brian R.
2015-03-01
This is the first book written on using Blender (an open source visualization suite widely used in the entertainment and gaming industries) for scientific visualization. It is a practical and interesting introduction to Blender for understanding key parts of 3D rendering and animation that pertain to the sciences via step-by-step guided tutorials. 3D Scientific Visualization with Blender takes you through an understanding of 3D graphics and modelling for different visualization scenarios in the physical sciences.
Remote Collaborative 3D Printing - Process Investigation
2016-04-01
COLLABORATIVE 3D PRINTING - PROCESS INVESTIGATION Cody M. Reese, PE CAD MODEL PRINT MODEL PRINT PREVIEW PRINTED PART AERIAL VIRTUAL This...REMOTE COLLABORATIVE 3D PRINTING - PROCESS INVESTIGATION 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Cody M. Reese...release; distribution is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT The Remote Collaborative 3D Printing project is a collaboration between
Microfabricating 3D Structures by Laser Origami
2011-11-09
10.1117/2.1201111.003952 Microfabricating 3D structures by laser origami Alberto Piqué, Scott Mathews, Andrew Birnbaum, and Nicholas Charipar A new...folding known as origami allows the transformation of flat patterns into 3D shapes. A similar approach can be used to generate 3D structures com... geometries . The overarching challenge is to move away from traditional planar semiconductor photolitho- graphic techniques, which severely limit the type of
3D Scientific Visualization with Blender
Kent, Brian R.
2015-03-01
This is the first book written on using Blender for scientific visualization. It is a practical and interesting introduction to Blender for understanding key parts of 3D rendering and animation that pertain to the sciences via step-by-step guided tutorials. 3D Scientific Visualization with Blender takes you through an understanding of 3D graphics and modelling for different visualization scenarios in the physical sciences.
International Nuclear Information System (INIS)
Hasegawa, Jun-ichi
1998-01-01
This paper presents an expert system called 3D-IMPRESS for supporting applications of three dimensional (3D) image processing. This system can automatically construct a 3D image processing procedure based on a pictorial example of the goal given by a user. In the paper, to evaluate the performance of the system, it was applied to construction of procedures for extracting specific component figures from practical chest X-ray CT images. (author)
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.
Perspectives on Materials Science in 3D
DEFF Research Database (Denmark)
Juul Jensen, Dorte
2012-01-01
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...
Getting started in 3D with Maya
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
Illustrating Mathematics using 3D Printers
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...
Xu, Minghui
2014-01-01
3D game has widely been accepted and loved by many game players. More and more different kinds of 3D games were developed to feed people’s needs. The most common programming language for development of 3D game is C++ nowadays. Python is a high-level scripting language. It is simple and clear. The concise syntax could speed up the development cycle. This project was to develop a 3D game using only Python. The game is about how a cat lives in the street. In order to live, the player need...
Dimensional accuracy of 3D printed vertebra
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.
Full-Angle Quaternions for Robustly Matching Vectors of 3D Rotations
Liwicki, Stephan; Pham, Minh-Tri; Zafeiriou, Stefanos; Pantic, Maja; Stenger, Björn
In this paper we introduce a new distance for robustly matching vectors of 3D rotations. A special representation of 3D rotations, which we coin full-angle quaternion (FAQ), allows us to express this distance as Euclidean. We apply the distance to the problems of 3D shape recognition from point
Directory of Open Access Journals (Sweden)
Lu-Chuan Ceng
2014-01-01
Full Text Available We first introduce and analyze one multistep iterative algorithm by hybrid shrinking projection method for finding a solution of the system of generalized equilibria with constraints of several problems: the generalized mixed equilibrium problem, finitely many variational inclusions, the minimization problem for a convex and continuously Fréchet differentiable functional, and the fixed-point problem of an asymptotically strict pseudocontractive mapping in the intermediate sense in a real Hilbert space. We prove strong convergence theorem for the iterative algorithm under suitable conditions. On the other hand, we also propose another multistep iterative algorithm involving no shrinking projection method and derive its weak convergence under mild assumptions.
Understanding 3D human torso shape via manifold clustering
Li, Sheng; Li, Peng; Fu, Yun
2013-05-01
Discovering the variations in human torso shape plays a key role in many design-oriented applications, such as suit designing. With recent advances in 3D surface imaging technologies, people can obtain 3D human torso data that provide more information than traditional measurements. However, how to find different human shapes from 3D torso data is still an open problem. In this paper, we propose to use spectral clustering approach on torso manifold to address this problem. We first represent high-dimensional torso data in a low-dimensional space using manifold learning algorithm. Then the spectral clustering method is performed to get several disjoint clusters. Experimental results show that the clusters discovered by our approach can describe the discrepancies in both genders and human shapes, and our approach achieves better performance than the compared clustering method.