Aziz Laghdir; Yves Fortin; Carmen Mariella De la Cruz; Hernández, Roger E.
2008-01-01
The objective of this study was to develop an accurate and simple method for measuring the engineering coefficients of the 3D elasticity tensor of wood. A method using a semi-ring extensometer (SRE) and a compression specimen (6-specimen technique) is proposed. The SRE is made of a semi-ring stainless steel blade pin-jointed to two aluminum fixing plates, and two resistance strain gauges bonded to the top and bottom faces of the blade at mid-span position. Groups of five matched compression s...
3D reconstruction of tensors and vectors
Defrise, Michel; Gullberg, Grant T.
2005-02-17
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.
Overall Dynamic Properties of 3-D periodic elastic composites
Srivastava, Ankit
2011-01-01
A method for the homogenization of 3-D periodic elastic composites is presented. It allows for the evaluation of the averaged overall frequency dependent dynamic material constitutive tensors relating the averaged dynamic ?eld variable tensors of velocity, strain, stress, and linear momentum. The formulation is based on micromechanical modeling of a representative unit cell of a composite proposed by Nemat-Nasser & Hori (1993), Nemat-Nasser et. al. (1982) and Mura (1987) and is the 3-D generalization of the 1-D elastodynamic homogenization scheme presented by Nemat-Nasser & Srivastava (2011). We show that for 3-D periodic composites the overall compliance (stiffness) tensor is hermitian, irrespective of whether the corresponding unit cell is geometrically or materially symmetric.Overall mass density is shown to be a tensor and, like the overall compliance tensor, always hermitian. The average strain and linear momentum tensors are, however, coupled and the coupling tensors are shown to be each others'...
3D Shape Similarity Using Vectors of Locally Aggregated Tensors
Tabia, Hedi; Picard, David; Laga, Hamid; Gosselin, Philippe-Henri
2013-01-01
IEEE International Conference on Image Processing 2013 International audience In this paper, we present an efficient 3D object retrieval method invariant to scale, orientation and pose. Our approach is based on the dense extraction of discriminative local descriptors extracted from 2D views. We aggregate the descriptors into a single vector signature using tensor products. The similarity between 3D models can then be efficiently computed with a simple dot product. Experiments on the SHR...
Causal Dynamical Triangulation of 3D Tensor Model
Kawabe, Hiroshi
2016-01-01
We extend the string field theory of the two dimensional (2D) generalized causal dynamical triangulation (GCDT) with the Ishibashi-Kawai (IK-) type interaction formulated by the matrix model, to the three dimensional (3D) model of the surface field theory. Based on the loop gas model, we construct a tensor model for the discretized surface field and then apply it the stochastic quantization method. In the double scaling limit, the model is characterized by two scaling dimensions $D$ and $D_N$, the power indices of the minimal length as the scaling parameter. The continuum GCDT model with the IK-type interaction is realized with the similar restriction in the $D_N$-$D$ space, to the 2D model. The distinct property in the 3D model is that the quantum effect contains the IK-type interaction only, while the ordinary splitting interaction is excluded.
Local Tensor Radiation Conditions For Elastic Waves
Krenk, S.; Kirkegaard, Poul Henning
2001-01-01
A local boundary condition is formulated, representing radiation of elastic waves from an arbitrary point source. The boundary condition takes the form of a tensor relation between the stress at a point on an arbitrarily oriented section and the velocity and displacement vectors at the point....... The tensor relation generalizes the traditional normal incidence impedance condition by accounting for the angle between wave propagation and the surface normal and by including a generalized stiffness term due to spreading of the waves. The effectiveness of the local tensor radiation condition...
General Expression of Elastic Tensor for Anisotropic Materials
HUANG Bo
2005-01-01
In order to formulate a general expression of elastic tensor for anisotropic materials, a method of tensor derivative is used for determining relationship between fourth-order elastic tensor and second-order structure tensor that has satisfied material symmetrical conditions. From this general expression of elastic tensor, specific expressions of elastic tensor for different anisotropic materials, such as isotropic materials, transverse isotropic materials and orthogonal-anisotropic materials, can be deduced. This expression underlies the scalar description of anisotropic factors, which are used for classifying and analyzing anisotropic materials. Cubic crystals are analyzed macroscopically by means of the general expression and anisotropic factor.
3-D joint inversion of the magnetotelluric phase tensor and vertical magnetic transfer functions
Tietze, Kristina; Ritter, Oliver; Egbert, Gary D.
2015-11-01
With advancing computational resources, 3-D inversion techniques have become feasible in recent years and are now a more widely used tool for magnetotelluric (MT) data interpretation. Galvanic distortion caused by small-scale near-surface inhomogeneities remains an obstacle for 3-D MT inversion which so far has experienced little attention. If not considered properly, the effect on 3-D inversion can be immense and result in erroneous subsurface models and interpretations. To tackle the problem we implemented inversion of the distortion-free phase tensor into the ModEM inversion package. The dimensionless phase tensor components describe only variations of the conductivity structure. When inverting these data, particular care has to be taken of the conductivity structure in the a priori model, which provides the reference frame when transferring the information from phase tensors into absolute conductivity values. Our results obtained with synthetic data show that phase tensor inversion can recover the regional conductivity structure in presence of galvanic distortion if the a priori model provides a reasonable assumption for the regional resistivity average. Joint inversion of phase tensor data and vertical magnetic transfer functions improves recovery of the absolute resistivity structure and is less dependent on the prior model. We also used phase tensor inversion for a data set of more than 250 MT sites from the central San Andreas fault, California, where a number of sites showed significant galvanic distortion. We find the regional structure of the phase tensor inversion results compatible with previously obtained models from impedance inversion. In the vicinity of distorted sites, phase tensor inversion models exhibit more homogeneous/smoother conductivity structures.
Elasticity tensor and ultrasonic velocities for anisotropic cubic polycrystal
2008-01-01
The orientation distribution of crystallites in a polycrystal can be described by the orientation distribution function(ODF) . The ODF can be expanded under the Wigner D-bases. The expanded coefficients in the ODF are called the texture coefficients. In this paper,we use the Clebsch-Gordan expression to derive an explicit expression of the elasticity tensor for an anisotropic cubic polycrystal. The elasticity tensor contains three material constants and nine texture coefficients. In order to measure the nine texture coefficients by ultrasonic wave,we give relations between the nine texture coefficients and ultrasonic propagation velocities. We also give a numerical example to check the relations.
Second order Method for Solving 3D Elasticity Equations with Complex and Sharp Interfaces
Wang , Bao; Xia, Kelin; Wei, Guowei
2014-01-01
Elastic materials are ubiquitous in nature and indispensable components in man-made devices and equipments. When a device or equipment involves composite or multiple elastic materials, elasticity interface problems come into play. The solution of three dimensional (3D) elasticity interface problems is significantly more difficult than that of elliptic counterparts due to the coupled vector components and cross derivatives in the governing elasticity equation. This work introduces the matched ...
Centroid Moment Tensor Inversion in a 3D heterogeneous Earth: Application to the Australasian region
Hejrani, B.; Tkalcic, H.; Fichtner, A.
2015-12-01
Australia is surrounded by active complex tectonic belts causing significant seismicity. The recent expansion of permanent seismic networks in the Australasian region provides great opportunity to study Earth structure and a great variety of physical mechanisms responsible for earthquakes.On one hand, a better understanding of the Australasian lithosphere, which is now available through tomographic images from full waveform modelling (Fichtner et al. 2010), provides a powerful tool to scrutinize the determination of earthquake source parameters. Even at relatively long periods (40-200s), the 3D effects of regional structure were shown to significantly alter the global centroid moment tensor solutions (Hingee et al. 2012). Thus, we can now explore other types of uncertainties and test the accuracy of global centroid moment tensor (GCMT) solution for the earthquakes in the Australasian region while checking for the systematic inconsistencies in the solutions. This has a significant bearing on tectonic interpretations. For example, azimuth and plunge of fault planes can be investigated in search for systematic biases.On the other hand, the time has come to take a full advantage of the 3D Earth structural model and embrace ongoing advances in computational power and storage. We develop a semi-automated procedure to calculate the Centroid Moment Tensors in a 3D heterogeneous Earth. We utilize the reciprocity theorem to create Green's functions for point sources covering seismogenic zones of Australasia. We focus on improving the capacity of the method to fully complement the existing monitoring tools at Geosciences Australia. Furthermore, we investigate the effects of detailed velocity structure on Centroid location and double-couple percentages. Moreover Azimuth and Plunge of focal mechanisms in GCMT (Global CMT), were investigated in search for any systematic bias.References: Fichtner, A., Kennett, B.L.N., Igel, H., Bunge, H.-P., 2010. Full waveform tomography for
Motion-induced phase error estimation and correction in 3D diffusion tensor imaging.
Van, Anh T; Hernando, Diego; Sutton, Bradley P
2011-11-01
A multishot data acquisition strategy is one way to mitigate B0 distortion and T2∗ blurring for high-resolution diffusion-weighted magnetic resonance imaging experiments. However, different object motions that take place during different shots cause phase inconsistencies in the data, leading to significant image artifacts. This work proposes a maximum likelihood estimation and k-space correction of motion-induced phase errors in 3D multishot diffusion tensor imaging. The proposed error estimation is robust, unbiased, and approaches the Cramer-Rao lower bound. For rigid body motion, the proposed correction effectively removes motion-induced phase errors regardless of the k-space trajectory used and gives comparable performance to the more computationally expensive 3D iterative nonlinear phase error correction method. The method has been extended to handle multichannel data collected using phased-array coils. Simulation and in vivo data are shown to demonstrate the performance of the method. PMID:21652284
In this paper, we derive the Green tensor of anisotropic gradient elasticity with separable weak non-locality, a special version of Mindlin's form II anisotropic gradient elasticity theory with up to six independent length scale parameters. The framework models materials where anisotropy is twofold, namely the bulk material anisotropy and a weak non-local anisotropy relevant at the nano-scale. In contrast with classical anisotropic elasticity, it is found that both the Green tensor and its gradient are non-singular at the origin, and that they rapidly converge to their classical counterparts away from the origin. Therefore, the Green tensor of Mindlin's anisotropic gradient elasticity with separable weak non-locality can be used as a physically-based regularization of the classical Green tensor for materials with strong anisotropy. - Highlights: • Theory of Mindlin's anisotropic gradient elasticity with separable weak non-locality is presented. • The non-singular (3D) Green tensor is given. • The gradient of the non-singular Green tensor is calculated
Eshelby tensor for a crack in an orthotropic elastic medium
Gruescu, Cosmin; Monchiet, Vincent; Kondo, Djimedo
2005-06-01
In the present Note, we provide new analytical expressions of the components of Hill tensor P (or equivalently the Eshelby tensor S) associated to an arbitrarily oriented crack in orthotropic elastic medium. The crack is modelled as an infinite cylinder along a symmetry axis of the matrix, with low aspect ratio. The three dimensional results obtained show explicitly the interaction between the primary (structural) anisotropy and the crack-induced anisotropy. They are validated by comparison with existing results in the case where the crack is in a symmetry plane. To cite this article: C. Gruescu et al., C. R. Mecanique 333 (2005).
A BOUNDARY INTEGRAL METHOD FOR COMPUTING ELASTIC MOMENT TENSORS FOR ELLIPSES AND ELLIPSOIDS
Habib Ammari; Hyeonbae Kang; Hyundae Lee
2007-01-01
The concept of elastic moment tensor occurs in several interesting contexts, in particular in imaging small elastic inclusions and in asymptotic models of dilute elastic composites.In this paper, we compute the elastic moment tensors for ellipses and ellipsoids by using a systematic method based on layer potentials. Our computations reveal an underlying elegant relation between the elastic moment tensors and the single layer potential.
Proton chemical shift tensors determined by 3D ultrafast MAS double-quantum NMR spectroscopy
Zhang, Rongchun; Mroue, Kamal H.; Ramamoorthy, Ayyalusamy, E-mail: ramamoor@umich.edu [Biophysics and Department of Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1055 (United States)
2015-10-14
Proton NMR spectroscopy in the solid state has recently attracted much attention owing to the significant enhancement in spectral resolution afforded by the remarkable advances in ultrafast magic angle spinning (MAS) capabilities. In particular, proton chemical shift anisotropy (CSA) has become an important tool for obtaining specific insights into inter/intra-molecular hydrogen bonding. However, even at the highest currently feasible spinning frequencies (110–120 kHz), {sup 1}H MAS NMR spectra of rigid solids still suffer from poor resolution and severe peak overlap caused by the strong {sup 1}H–{sup 1}H homonuclear dipolar couplings and narrow {sup 1}H chemical shift (CS) ranges, which render it difficult to determine the CSA of specific proton sites in the standard CSA/single-quantum (SQ) chemical shift correlation experiment. Herein, we propose a three-dimensional (3D) {sup 1}H double-quantum (DQ) chemical shift/CSA/SQ chemical shift correlation experiment to extract the CS tensors of proton sites whose signals are not well resolved along the single-quantum chemical shift dimension. As extracted from the 3D spectrum, the F1/F3 (DQ/SQ) projection provides valuable information about {sup 1}H–{sup 1}H proximities, which might also reveal the hydrogen-bonding connectivities. In addition, the F2/F3 (CSA/SQ) correlation spectrum, which is similar to the regular 2D CSA/SQ correlation experiment, yields chemical shift anisotropic line shapes at different isotropic chemical shifts. More importantly, since the F2/F1 (CSA/DQ) spectrum correlates the CSA with the DQ signal induced by two neighboring proton sites, the CSA spectrum sliced at a specific DQ chemical shift position contains the CSA information of two neighboring spins indicated by the DQ chemical shift. If these two spins have different CS tensors, both tensors can be extracted by numerical fitting. We believe that this robust and elegant single-channel proton-based 3D experiment provides useful atomistic
Towards an Anisotropic Whole Mantle 3D Elastic Velocity Model
Panning, M. P.; Romanowicz, B.; Gung, Y.
2001-12-01
Many studies have documented the existence of anisotropy in the earth's upper mantle, concentrated in the top 200 km. This evidence comes from the study of surface waves as well as shear wave splitting. There is also evidence for shear wave splitting in D", at least in well sampled regions. There are some hints of anisotropy at the base of the transition zone. Tomographic models of the upper mantle have been developed with simplifying assumptions about the nature of the anisotropy, in order to minimize the number of free parameters in the inversions. Some assume transverse isotropy (e.g Ekström and Dziewonski, 1997), others include additional degrees of freedom with some realistic constraints on mineralogy (e.g. Montagner and Tanimoto, 1991). Our goal is to investigate anisotropy in the whole mantle, using the framework of waveform inversion, and the nonlinear asymptotic mode coupling theory (NACT), previously developed and applied to the construction of whole-mantle SH velocity models (Li and Romanowicz, 1996; Mégnin and Romanowicz, 2000). For this we require a 3 component dataset, and we have extended our automatic transverse (T) component wavepicking procedures to the vertical (Z) and longitudinal (L) component - a non-trivial task given the large number of phases present in the coupled P-SV system. A useful initial assumption, for which the theory has been readily adapted, is that of transverse isotropy. As a first step towards this, we have been investigating inversions using T component and Z,L component data separately. In particular, this allows us to explore the sampling that can be achieved with Z,L component data alone in the deepest part of the mantle. Indeed, D" is in general much better sampled in SH than in SV, owing to the availability of SHdiff at large distances, while SVdiff decays more rapidly due to mantle-core coupling. We present the results of our resolution experiments and discuss the differences between the 3D SV model obtained in well
Liang, Yun; Zhu, Hui; Friedman, Morton H.
2010-11-01
Intravascular ultrasound (IVUS) elastography is a promising tool for studying atherosclerotic plaque composition and assessing plaque vulnerability. Current IVUS elastography techniques can measure the 1D or 2D strain of the vessel wall using various motion tracking algorithms. Since biological soft tissue tends to deform non-uniformly in 3D, measurement of the complete 3D strain tensor is desirable for more rigorous analysis of arterial wall mechanics. In this paper, we extend our previously developed method of 2D arterial wall strain measurement based on non-rigid image registration into 3D strain measurement. The new technique registers two image volumes acquired from the same vessel segment under different levels of luminal pressure and longitudinal stress. The 3D displacement field obtained from the image registration is used to calculate the local 3D strain tensor. From the 3D strain tensor, radial, circumferential and longitudinal strain distributions can be obtained and displayed. This strain tensor measurement method is validated and evaluated using IVUS images of healthy porcine carotid arteries subjected to a luminal pressure increase and longitudinal stretch. The ability of the algorithm to overcome systematic noise was tested, as well as the consistency of the results under different longitudinal frame resolutions.
ELASTIC BEHAVIOR ANALYSIS OF 3D ANGLE-INTERLOCK WOVEN CERAMIC COMPOSITES
Chang Yanjun; Jiao Guiqiong; Wang Bo; Liu Wei
2006-01-01
A micromechanical model for elastic behavior analysis of angle-interlock woven ceramic composites is proposed in this paper. This model takes into account the actual fabric structure by considering the fiber undulation and continuity in space, the cavities between adjacent yarns and the actual cross-section geometry of the yarn. Based on the laminate theory, the elastic properties of 3D angle-interlock woven ceramic composites are predicted. Different numbers of interlaced wefts have almost the same elastic moduli. The thickness of ceramic matrix has little effect on elastic moduli. When the undulation ratio increases longitudinal modulus decreases and the other Young's moduli increase. Good agreement between theoretical predictions and experimental results demonstrates the feasibility of the proposed model in analyzing the elastic properties of3D angle-interlock woven ceramic composites. The results of this paper verify the fact that the method of analyzing polyester matrix composites is suitable for woven ceramic composites.
3D Elastic Registration of Ultrasound Images Based on Skeleton Feature
LI Dan-dan; LIU Zhi-Yan; SHEN Yi
2005-01-01
In order to eliminate displacement and elastic deformation between images of adjacent frames in course of 3D ultrasonic image reconstruction, elastic registration based on skeleton feature was adopt in this paper. A new automatically skeleton tracking extract algorithm is presented, which can extract connected skeleton to express figure feature. Feature points of connected skeleton are extracted automatically by accounting topical curvature extreme points several times. Initial registration is processed according to barycenter of skeleton. Whereafter, elastic registration based on radial basis function are processed according to feature points of skeleton. Result of example demonstrate that according to traditional rigid registration, elastic registration based on skeleton feature retain natural difference in shape for organ's different part, and eliminate slight elastic deformation between frames caused by image obtained process simultaneously. This algorithm has a high practical value for image registration in course of 3D ultrasound image reconstruction.
A comprehensive statistical framework for elastic shape analysis of 3D faces
Kurtek, Sebastian; Drira, Hassen
2015-01-01
We develop a comprehensive statistical framework for analyzing shapes of 3D faces. In particular, we adapt a recent elastic shape analysis framework to the case of hemispherical surfaces, and explore its use in a number of processing applications. This framework provides a parameterization-invariant, elastic Riemannian metric, which allows the development of mathematically rigorous tools for statistical analysis. Specifically, this paper describes methods for registration, comparison and defo...
Laplace-domain waveform modeling and inversion for the 3D acoustic-elastic coupled media
Shin, Jungkyun; Shin, Changsoo; Calandra, Henri
2016-06-01
Laplace-domain waveform inversion reconstructs long-wavelength subsurface models by using the zero-frequency component of damped seismic signals. Despite the computational advantages of Laplace-domain waveform inversion over conventional frequency-domain waveform inversion, an acoustic assumption and an iterative matrix solver have been used to invert 3D marine datasets to mitigate the intensive computing cost. In this study, we develop a Laplace-domain waveform modeling and inversion algorithm for 3D acoustic-elastic coupled media by using a parallel sparse direct solver library (MUltifrontal Massively Parallel Solver, MUMPS). We precisely simulate a real marine environment by coupling the 3D acoustic and elastic wave equations with the proper boundary condition at the fluid-solid interface. In addition, we can extract the elastic properties of the Earth below the sea bottom from the recorded acoustic pressure datasets. As a matrix solver, the parallel sparse direct solver is used to factorize the non-symmetric impedance matrix in a distributed memory architecture and rapidly solve the wave field for a number of shots by using the lower and upper matrix factors. Using both synthetic datasets and real datasets obtained by a 3D wide azimuth survey, the long-wavelength component of the P-wave and S-wave velocity models is reconstructed and the proposed modeling and inversion algorithm are verified. A cluster of 80 CPU cores is used for this study.
3D inversion of full gravity gradient tensor data using SL0 sparse recovery
Meng, Zhaohai
2016-04-01
We present a new method dedicated to the interpretation of full gravity gradient tensor data, based on SL0 sparse recovery inversion. The SL0 sparse recovery method aims to find out the minimum value of the objective function to fit the data function and to solve the non-zero solution to the objective function. Based on continuous iteration, we can easily obtain the final global minimum (namely the property and space attribute of the inversion target). We consider which type of tensor data combination produces the best inversion results based on the inversion results of different full gravity gradient tensor data combinations (separate tensor data and combined tensor data). We compare the recovered models obtained by inverting the different combinations of different gravity gradient tensor components to understand how different component combinations contribute to the resolution of the recovered model. Based on the comparison between the SL0 sparse recovery inversion results and the smoothest and focusing inversion results of the full gravity gradient tensor data, we show that SL0 sparse recovery inversion can obtain more stable and efficient inversion results with relatively sharp edge information, and that this method can also produce a stable solution of the inverse problem for complex geological structures. This new method to resolve very large full gravity gradient tensor datasets has the considerable advantage of being highly efficient; the full gravity gradient tensor inversion requires very little time. This new method is very effective in explaining the full gravity tensor which is very sensitive to small changes in local anomaly. The numerical simulation and inversion results of the compositional model indicates that including multiple components for inversion increases the resolution of the recovered density model and improves the structure delineation. We apply our inversion method to invert the gravity gradient tensor survey data from the Vinton salt
On Prediction of 3d Stress State in Elastic Shell by Higher-order Shell Formulations
Brank, Boštjan; Ibrahimbegović, Adnan; Bohinc, Uroš
2008-01-01
In this work we study the accuracy of modem higher-order shell finite element formulations in computation of 3d stress state in elastic shells. In that sense we compare three higher-order shell models: (i) with seven dislacement-like kinematic parameters, and (ii, iii) with six displacement-like kinematic parameters plus one strain-like kinematic parameter introduced by two different versions of enhanced assumed strain (EAS) concept. The finite element approximations of all shell models are b...
Freedman, Daniel A.; Roundy, D.; Arias, T. A.
2008-01-01
We present a study of the local strain effects associated with vacancy defects in strontium titanate and report the first calculations of elastic dipole tensors and chemical strains for point defects in perovskites. The combination of local and long-range results will enable determination of x-ray scattering signatures that can be compared with experiments. We find that the oxygen vacancy possesses a special property -- a highly anisotropic elastic dipole tensor which almost vanishes upon ave...
Moussawi, Ali
2015-02-24
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 of the constitutive compatibility method for tackling such an inverse problem, provided an appropriate domain decomposition technique is introduced. In the method described here, the statically admissible stress field that can be related through the known constitutive symmetry to the kinematic observations is sought through minimization of an objective function, which measures the violation of constitutive compatibility. After this stress reconstruction, the local material parameters are identified with the given kinematic observations using the constitutive equation. Here, we first adapt this method to solve 3D identification problems and then implement it within a domain decomposition framework which allows for reduced computational load when handling larger problems.
X-ray scattering in the elastic regime as source for 3D imaging reconstruction technique
Kocifaj, Miroslav; Mego, Michal
2015-11-01
X-ray beams propagate across a target object before they are projected onto a regularly spaced array of detectors to produce a routine X-ray image. A 3D attenuation coefficient distribution is obtained by tomographic reconstruction where scattering is usually regarded as a source of parasitic signals which increase the level of electromagnetic noise that is difficult to eliminate. However, the elastically scattered radiation could be a valuable source of information, because it can provide a 3D topology of electron densities and thus contribute significantly to the optical characterization of the scanned object. The scattering and attenuation data form a complementary base for concurrent retrieval of both electron density and attenuation coefficient distributions. In this paper we developed the 3D reconstruction method that combines both data inputs and produces better image resolution compared to traditional technology.
崔洁; 江权; 冯夏庭; 李邵军; 高红; 李帅军
2016-01-01
Discontinuities constitute an integral part of rock mass and inherently affect its anisotropic deformation behavior. This work focuses on the equivalent elastic deformation of rock mass with multiple persistent joint sets. A new method based on the space geometric and mechanical properties of the modified crack tensor is proposed, providing an analytical solution for the equivalent elastic compliance tensor of rock mass. A series of experiments validate the capability of the compliance tensor to accurately represent the deformation of rock mass with multiple persistent joint sets, based on conditions set by the basic hypothesis. The spatially varying rules of the equivalent elastic parameters of rock mass with a single joint set are analyzed to reveal the universal law of the stratified rock mass.
Numerical study of elastic turbulence in a 3D curvilinear micro-channel
Zhang, Hongna; Kunugi, Tomoaki; Li, Fengchen
2012-11-01
Elastic turbulence is an intriguing phenomenon of viscoelastic fluid flow, and dominated by the strong nonlinear elasticity due to the existence of flexible microstructures. It implies the possibility to generate a turbulent state (so-called an elastic turbulence) in the micro-scale devices by introducing the viscoelastic fluids, which could significantly enhance the mixing efficiency therein. Several experiments have been carried out to study its characteristics and underlying physics. However, the difficulty in measuring the flow information and behaviors of the microstructures, especially in the cross section normal to the mean flow direction, limits our current understanding and controlling. In the present study, the nondimensionalization method in which the characteristic velocity is defined as the ratio of the solution viscosity to the width of the channel was adopted to simulate the elastic turbulence in the micro-scale devices. And the elastic turbulent flow was obtained numerically in the 3D curvilinear micro-channel. Therein, the characteristics of the velocity field and polymer's behavior are discussed. Moreover, the energy transfer between the kinetic energy and the polymer's elastic energy is also investigated to understand its physical mechanism. Supported by the Japan Society for the Promotion of Science research fellowship and the Ministry of Education, Culture, Sports, Science and Technology via `Energy Science in the Age of Global Warming' of Global Center of Excellence (G-COE) program (J-051).
Ultrasound elastic tensor imaging: comparison with MR diffusion tensor imaging in the myocardium
Lee, Wei-Ning; Larrat, Benoît; Pernot, Mathieu; Tanter, Mickaël
2012-08-01
We have previously proven the feasibility of ultrasound-based shear wave imaging (SWI) to non-invasively characterize myocardial fiber orientation in both in vitro porcine and in vivo ovine hearts. The SWI-estimated results were in good correlation with histology. In this study, we proposed a new and robust fiber angle estimation method through a tensor-based approach for SWI, coined together as elastic tensor imaging (ETI), and compared it with magnetic resonance diffusion tensor imaging (DTI), a current gold standard and extensively reported non-invasive imaging technique for mapping fiber architecture. Fresh porcine (n = 5) and ovine (n = 5) myocardial samples (20 × 20 × 30 mm3) were studied. ETI was firstly performed to generate shear waves and to acquire the wave events at ultrafast frame rate (8000 fps). A 2.8 MHz phased array probe (pitch = 0.28 mm), connected to a prototype ultrasound scanner, was mounted on a customized MRI-compatible rotation device, which allowed both the rotation of the probe from -90° to 90° at 5° increments and co-registration between two imaging modalities. Transmural shear wave speed at all propagation directions realized was firstly estimated. The fiber angles were determined from the shear wave speed map using the least-squares method and eigen decomposition. The test myocardial sample together with the rotation device was then placed inside a 7T MRI scanner. Diffusion was encoded in six directions. A total of 270 diffusion-weighted images (b = 1000 s mm-2, FOV = 30 mm, matrix size = 60 × 64, TR = 6 s, TE = 19 ms, 24 averages) and 45 B0 images were acquired in 14 h 30 min. The fiber structure was analyzed by the fiber-tracking module in software, MedINRIA. The fiber orientation in the overlapped myocardial region which both ETI and DTI accessed was therefore compared, thanks to the co-registered imaging system. Results from all ten samples showed good correlation (r2 = 0.81, p 0.05, unpaired, one-tailed t-test, N = 10). In
Ultrasound elastic tensor imaging: comparison with MR diffusion tensor imaging in the myocardium
We have previously proven the feasibility of ultrasound-based shear wave imaging (SWI) to non-invasively characterize myocardial fiber orientation in both in vitro porcine and in vivo ovine hearts. The SWI-estimated results were in good correlation with histology. In this study, we proposed a new and robust fiber angle estimation method through a tensor-based approach for SWI, coined together as elastic tensor imaging (ETI), and compared it with magnetic resonance diffusion tensor imaging (DTI), a current gold standard and extensively reported non-invasive imaging technique for mapping fiber architecture. Fresh porcine (n = 5) and ovine (n = 5) myocardial samples (20 × 20 × 30 mm3) were studied. ETI was firstly performed to generate shear waves and to acquire the wave events at ultrafast frame rate (8000 fps). A 2.8 MHz phased array probe (pitch = 0.28 mm), connected to a prototype ultrasound scanner, was mounted on a customized MRI-compatible rotation device, which allowed both the rotation of the probe from −90° to 90° at 5° increments and co-registration between two imaging modalities. Transmural shear wave speed at all propagation directions realized was firstly estimated. The fiber angles were determined from the shear wave speed map using the least-squares method and eigen decomposition. The test myocardial sample together with the rotation device was then placed inside a 7T MRI scanner. Diffusion was encoded in six directions. A total of 270 diffusion-weighted images (b = 1000 s mm−2, FOV = 30 mm, matrix size = 60 × 64, TR = 6 s, TE = 19 ms, 24 averages) and 45 B0 images were acquired in 14 h 30 min. The fiber structure was analyzed by the fiber-tracking module in software, MedINRIA. The fiber orientation in the overlapped myocardial region which both ETI and DTI accessed was therefore compared, thanks to the co-registered imaging system. Results from all ten samples showed good correlation (r2 = 0.81, p 0.05, unpaired, one-tailed t-test, N = 10
2D Riemann-Christoffel curvature tensor via a 3D space using a specialized permutation scheme
Omerbashich, Mensur
2009-01-01
When a space in which Christoffel symbols of the second kind are symmetrical in lower indices exists, it makes for a supplement to the standard procedure when a 2D surface is normally induced from the geometry of the surrounding 3D space in which the surface is embedded. There it appears appropriate to use a scheme for straightforward permutation of indices of Gkij, when such a space would make this transformation possible, so as to obtain the components of the 2D Riemann-Christoffel tensor (here expressed in geodetic coordinates for an ellipsoid of revolution, of use in geophysics). By applying my scheme I find the corresponding indices in 2D and 3D supplement-spaces, and I compute components of the Riemann-Christoffel tensor. By operating over the elements of the projections alone, the all-known value of 1/MN for the Gaussian curvature on an ellipsoid of revolution is obtained. To further validate my scheme, I show that in such a 3D space the tangent vector to a PHI-curve for LAM=const1 would be parallel to...
Mathematical Description and Finite Element Equation of 3D Coupled Thermo-elastic Contact Problem
Shi Yu; Xiao Yougang; Chen Guoxin
2006-01-01
Through defining slide yield function and floating potential function of thermo-contact surface, the complementary equation of thermo-contact boundary has been reached, the fundamental equations to solve 3D thermo-contact coupled problem have been listed. On this foundation, the finite element equation and definite solution condition of contact heat transfer have been given out. Based on virtual work principle and contact element technology, the finite element equation of 3D elastic contact system has been deduced under the effect of thermal stress. The pseudo load brought by contact gap have been introduced into this equation in order to reflect the contact state change. During iteration, once contact rigidity matrix is formed, it won't change,which will make calculation reduce greatly.
2D Riemann-Christoffel curvature tensor via a 3D space using a specialized permutation scheme
Omerbashich, Mensur
2009-01-01
When a space in which Christoffel symbols of the second kind are symmetrical in lower indices exists, it makes for a supplement to the standard procedure when a 2D surface is normally induced from the geometry of the surrounding 3D space in which the surface is embedded. There it appears appropriate to use a scheme for straightforward permutation of indices of Gkij, when such a space would make this transformation possible, so as to obtain the components of the 2D Riemann-Christoffel tensor (...
3D PATTERN OF BRAIN ABNORMALITIES IN WILLIAMS SYNDROME VISUALIZED USING TENSOR-BASED MORPHOMETRY
Chiang, Ming-Chang; Reiss, Allan L.; Lee, Agatha D.; Bellugi, Ursula; Galaburda, Albert M.; Korenberg, Julie R.; Mills, Debra L.; Toga, Arthur W.; Thompson, Paul M.
2007-01-01
Williams syndrome (WS) is a neurodevelopmental disorder associated with deletion of ~20 contiguous genes in chromosome band 7q11.23. Individuals with WS exhibit mild to moderate mental retardation, but are relatively more proficient in specific language and musical abilities. We used tensor-based morphometry (TBM) to visualize the complex pattern of gray/white matter reductions in WS, based on fluid registration of structural brain images.
Jammed elastic shells - a 3D experimental soft frictionless granular system
Jose, Jissy; Blab, Gerhard A.; van Blaaderen, Alfons; Imhof, Arnout
2015-03-01
We present a new experimental system of monodisperse, soft, frictionless, fluorescent labelled elastic shells for the characterization of structure, universal scaling laws and force networks in 3D jammed matter. The interesting fact about these elastic shells is that they can reversibly deform and therefore serve as sensors of local stress in jammed matter. Similar to other soft particles, like emulsion droplets and bubbles in foam, the shells can be packed to volume fractions close to unity, which allows us to characterize the contact force distribution and universal scaling laws as a function of volume fraction, and to compare them with theoretical predictions and numerical simulations. However, our shells, unlike other soft particles, deform rather differently at large stresses. They deform without conserving their inner volume, by forming dimples at contact regions. At each contact one of the shells buckled with a dimple and the other remained spherical, closely resembling overlapping spheres. We conducted 3D quantitative analysis using confocal microscopy and image analysis routines specially developed for these particles. In addition, we analysed the randomness of the process of dimpling, which was found to be volume fraction dependent.
Panebianco, Valeria, E-mail: valeria.panebianco@gmail.com [Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Viale Regina Elena, 324, 00161 Rome (Italy); Barchetti, Flavio [Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Viale Regina Elena, 324, 00161 Rome (Italy); Sciarra, Alessandro [Department of Urology, Sapienza University of Rome (Italy); Marcantonio, Andrea; Zini, Chiara [Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Viale Regina Elena, 324, 00161 Rome (Italy); Salciccia, Stefano [Department of Urology, Sapienza University of Rome (Italy); Collettini, Federico [Department of Radiology, Charité, Berlin (Germany); Gentile, Vincenzo [Department of Urology, Sapienza University of Rome (Italy); Hamm, Bernard [Department of Radiology, Charité, Berlin (Germany); Catalano, Carlo [Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Viale Regina Elena, 324, 00161 Rome (Italy)
2013-10-01
Objectives: To evaluate if Diffusion Tensor Imaging technique (DTI) can improve the visualization of periprostatic nerve fibers describing the location and distribution of entire neurovascular plexus around the prostate in patients who are candidates for prostatectomy. Materials and methods: Magnetic Resonance Imaging (MRI), including a 2D T2-weighted FSE sequence in 3 planes, 3D T2-weighted and DTI using 16 gradient directions and b = 0 and 1000, was performed on 36 patients. Three out of 36 patients were excluded from the analysis due to poor image quality (blurring N = 2, artifact N = 1). The study was approved by local ethics committee and all patients gave an informed consent. Images were evaluated by two radiologists with different experience in MRI. DTI images were analyzed qualitatively using dedicated software. Also 2D and 3D T2 images were independently considered. Results: 3D-DTI allowed description of the entire plexus of the periprostatic nerve fibers in all directions, while 2D and 3D T2 morphological sequences depicted part of the fibers, in a plane by plane analysis of fiber courses. DTI demonstrated in all patients the dispersion of nerve fibers around the prostate on both sides including the significant percentage present in the anterior and anterolateral sectors. Conclusions: DTI offers optimal representation of the widely distributed periprostatic plexus. If validated, it may help guide nerve-sparing radical prostatectomy.
Objectives: To evaluate if Diffusion Tensor Imaging technique (DTI) can improve the visualization of periprostatic nerve fibers describing the location and distribution of entire neurovascular plexus around the prostate in patients who are candidates for prostatectomy. Materials and methods: Magnetic Resonance Imaging (MRI), including a 2D T2-weighted FSE sequence in 3 planes, 3D T2-weighted and DTI using 16 gradient directions and b = 0 and 1000, was performed on 36 patients. Three out of 36 patients were excluded from the analysis due to poor image quality (blurring N = 2, artifact N = 1). The study was approved by local ethics committee and all patients gave an informed consent. Images were evaluated by two radiologists with different experience in MRI. DTI images were analyzed qualitatively using dedicated software. Also 2D and 3D T2 images were independently considered. Results: 3D-DTI allowed description of the entire plexus of the periprostatic nerve fibers in all directions, while 2D and 3D T2 morphological sequences depicted part of the fibers, in a plane by plane analysis of fiber courses. DTI demonstrated in all patients the dispersion of nerve fibers around the prostate on both sides including the significant percentage present in the anterior and anterolateral sectors. Conclusions: DTI offers optimal representation of the widely distributed periprostatic plexus. If validated, it may help guide nerve-sparing radical prostatectomy
Spatial Parallelism of a 3D Finite Difference, Velocity-Stress Elastic Wave Propagation Code
MINKOFF,SUSAN E.
1999-12-09
Finite difference methods for solving the wave equation more accurately capture the physics of waves propagating through the earth than asymptotic solution methods. Unfortunately. finite difference simulations for 3D elastic wave propagation are expensive. We model waves in a 3D isotropic elastic earth. The wave equation solution consists of three velocity components and six stresses. The partial derivatives are discretized using 2nd-order in time and 4th-order in space staggered finite difference operators. Staggered schemes allow one to obtain additional accuracy (via centered finite differences) without requiring additional storage. The serial code is most unique in its ability to model a number of different types of seismic sources. The parallel implementation uses the MP1 library, thus allowing for portability between platforms. Spatial parallelism provides a highly efficient strategy for parallelizing finite difference simulations. In this implementation, one can decompose the global problem domain into one-, two-, and three-dimensional processor decompositions with 3D decompositions generally producing the best parallel speed up. Because i/o is handled largely outside of the time-step loop (the most expensive part of the simulation) we have opted for straight-forward broadcast and reduce operations to handle i/o. The majority of the communication in the code consists of passing subdomain face information to neighboring processors for use as ''ghost cells''. When this communication is balanced against computation by allocating subdomains of reasonable size, we observe excellent scaled speed up. Allocating subdomains of size 25 x 25 x 25 on each node, we achieve efficiencies of 94% on 128 processors. Numerical examples for both a layered earth model and a homogeneous medium with a high-velocity blocky inclusion illustrate the accuracy of the parallel code.
Simulation domain size requirements for elastic response of 3D polycrystalline materials
Ozturk, Tugce; Stein, Clayton; Pokharel, Reeju; Hefferan, Christopher; Tucker, Harris; Jha, Sushant; John, Reji; Lebensohn, Ricardo A.; Kenesei, Peter; Suter, Robert M.; Rollett, Anthony D.
2016-01-01
A fast Fourier transform (FFT) based spectral algorithm is used to compute the full field mechanical response of polycrystalline microstructures. The field distributions in a specific region are used to determine the sensitivity of the method to the number of surrounding grains through quantification of the divergence of the field values from the largest simulation domain, as successively smaller surrounding volumes are included in the simulation. The analysis considers a mapped 3D structure where the location of interest is taken to be a particular pair of surface grains that enclose a small fatigue crack, and synthetically created statistically representative microstructures to further investigate the effect of anisotropy, loading condition, loading direction, and texture. The synthetic structures are generated via DREAM3D and the measured material is a cyclically loaded, Ni-based, low solvus high refractory (LSHR) superalloy that was characterized via 3D high energy x-ray diffraction microscopy (HEDM). Point-wise comparison of distributions in the grain pairs shows that, in order to obtain a Pearson correlation coefficient larger than 99%, the domain must extend to at least the third nearest neighbor. For an elastic FFT calculation, the stress-strain distributions are not sensitive to the shape of the domain. The main result is that convergence can be specified in terms of the number of grains surrounding a region of interest.
Irreducible decomposition of strain gradient tensor in isotropic strain gradient elasticity
Lazar, Markus
2016-01-01
In isotropic strain gradient elasticity, we decompose the strain gradient tensor into its irreducible pieces under the n-dimensional orthogonal group O(n). Using the Young tableau method for traceless tensors, four irreducible pieces (n>2), which are canonical, are obtained. In three dimensions, the strain gradient tensor can be decomposed into four irreducible pieces with 7+5+3+3 independent components whereas in two dimensions, the strain gradient tensor can be decomposed into three irreducible pieces with 2+2+2 independent components. The knowledge of these irreducible pieces is extremely useful when setting up constitutive relations and strain energy.
Green-Naghdi rate of the Kirchhoff stress and deformation rate: the elasticity tensor
Bellini, Chiara; Federico, Salvatore
2015-06-01
The elasticity tensor providing the power-conjugation of the Green-Naghdi rate of the Kirchhoff stress and the deformation rate is required, e.g. by the commercially available Finite Element package ABAQUS/Standard for the material user subroutine UMAT, used to input material behaviours other than those included in the libraries of the package. This elasticity tensor had been studied in the literature, but its symmetries have only been briefly discussed, and only its component form in Cartesian coordinates was known. In this work, we derived a covariant, component-free expression of this elasticity tensor and thoroughly studied its symmetries. We found that, although symmetry on both pair of feet (indices) has been deemed to be desirable in the literature, the expression of the tensor available to-date in fact possesses only symmetry on the first pair of feet (indices), whereas the second pair lacks symmetry, and therefore carries a skew-symmetric contribution. This contribution is unnecessary, as it is automatically filtered in the contraction of the elasticity tensor with the symmetric deformation rate tensor. In order to avoid carrying this unnecessary skew-symmetric contribution in the computations, we employ a tensor identity that naturally symmetrises the second pair of feet of the elasticity tensor. We demonstrated the validity and robustness of the implementation of the user-defined material based on this tensor representation by simulating a benchmark problem consisting in biaxial tests of porcine and human atrial tissue, with material properties taken from previously performed experiments. We compared the results obtained by means of our user-defined material and those obtained through an equivalent built-in material, and obtained identical results.
Compact Vectors of Locally Aggregated Tensors for 3D shape retrieval
Tabia, Hedi; Picard, David; Laga, Hamid; Gosselin, Philippe-Henri
2013-01-01
International audience During the last decade, a significant attention has been paid, by the computer vision and the computer graphics communities, to three dimensional (3D) object retrieval. Shape retrieval methods can be divided into three main steps: the shape descriptors extraction, the shape signatures and their associated similarity measures, and the machine learning relevance functions. While the first and the last points have vastly been addressed in recent years, in this paper, we...
GREEN＇S FUNCTION AND EFFECTIVE ELASTIC STIFFNESS TENSOR FOR ARBITRARY AGGREGATES OF CUBIC CRYSTALS
HuangMojia; ZhengChaomei
2004-01-01
A closed but approximate formula of Green's function for an arbitrary aggregate of cubic crystallites is given to derive the effective elastic stiffness tensor of the polycrystal. This formula, which includes three elastic constants of single cubic crystal and five texture coefficients,accounts for the effects of the orientation distribution function (ODF) up to terms linear in the texture coefficients. Thus it is expected that our formula would be applicable to arbitrary aggregates with weak texture or to materials such as aluminum whose single crystal has weak anisotropy.Three examples are presented to compare predictions from our formula with those from Nishioka and Lothe's formula and Synge's contour integral through numerical integration. As an application of Green's function, we briefly describe the procedure of deriving the effective elastic stiffness tensor for an orthorhombic aggregate of cubic crystallites. The comparison of the computational results given by the finite element method and our effective elastic stiffness tensor is made by an example.
Spatio-Temporal Video Object Segmentation via Scale-Adaptive 3D Structure Tensor
Hai-Yun Wang
2004-06-01
Full Text Available To address multiple motions and deformable objects' motions encountered in existing region-based approaches, an automatic video object (VO segmentation methodology is proposed in this paper by exploiting the duality of image segmentation and motion estimation such that spatial and temporal information could assist each other to jointly yield much improved segmentation results. The key novelties of our method are (1 scale-adaptive tensor computation, (2 spatial-constrained motion mask generation without invoking dense motion-field computation, (3 rigidity analysis, (4 motion mask generation and selection, and (5 motion-constrained spatial region merging. Experimental results demonstrate that these novelties jointly contribute much more accurate VO segmentation both in spatial and temporal domains.
Yu eCai
2011-10-01
Full Text Available High resolution diffusion tensor imaging (DTI can provide important information on brain development, yet it is challenging in live neonatal rats due to the small size of neonatal brain and motion-sensitive nature of DTI. Imaging in live neonatal rats has clear advantages over fixed brain scans, as longitudinal and functional studies would be feasible to understand neuro-developmental abnormalities. In this study, we developed imaging strategies that can be used to obtain high resolution 3D DTI images in live neonatal rats at postnatal day 5 (PND5 and postnatal day 14 (PND14, using only 3 hours of imaging acquisition time. An optimized 3D DTI pulse sequence and appropriate animal setup to minimize physiological motion artifacts are the keys to successful high resolution 3D DTI imaging. Thus, a 3D RARE DTI sequence with twin navigator echoes was implemented to accelerate imaging acquisition time and minimize motion artifacts. It has been suggested that neonatal mammals possess a unique ability to tolerate mild to moderate hypothermia and hypoxia without long term impact. Thus, we additionally utilized this ability to minimize motion artifacts in MR images by carefully suppressing the respiratory rate to around 15/min for PND5 and 30/min for PND14 using mild to moderate hypothermia. These imaging strategies have been successfully implemented to study how the effect of cocaine exposure in dams might affect brain development in their rat pups. Image quality resulting from this in vivo DTI study was comparable to ex vivo scans. FA values were also similar between the live and fixed brain scans. The capability of acquiring high quality in vivo DTI imaging offers a valuable opportunity to study many neurological disorders in brain development in an authentic living environment.
Mollemans, W.; Schutyser, F.; Nadjmi, N.; Maes, F.; Suetens, P.
2006-03-01
In this paper we present an extensive quantitative validation on 3D facial soft tissue simulation for maxillofacial surgery planning. The study group contained 10 patients. In previous work we presented a new Mass Tensor Model to simulate the new facial appearance after maxillofacial surgery in a fast way. 10 patients were preoperatively CT-scanned and the surgical intervention was planned. 4 months after surgery, a post-operative control CT was acquired. In this study, the simulated facial outlook is compared with post-operative image data. After defining corresponding points between the predicted and actual post-operative facial skin surface, using a variant of the non-rigid TPS-RPM algorithm, distances between these correspondences are quantified and visualized in 3D. As shown, the average median distance measures only 0.60 mm and the average 90% percentile stays below 1.5 mm. We can conclude that our model clearly provides an accurate prediction of the real post-operative outcome and is therefore suitable for use in clinical practice.
Ice-shelf forced vibrations modelled with a full 3-D elastic model
Y. V. Konovalov
2014-12-01
Full Text Available Ice-shelf forced vibrations modelling was performed using a full 3-D finite-difference elastic model, which takes into account sub-ice seawater flow. The sub-ice seawater flow was described by the wave equation, so the ice-shelf flexures result from the hydrostatic pressure perturbations in sub-ice seawater layer. The numerical experiments were performed for idealized ice-shelf geometry, which was considered in the numerical experiments in Holdsworth and Glynn (1978. The ice-plate vibrations were modelled for harmonic ingoing pressure perturbations and for a wide spectrum of the ocean swell periodicities, ranging from infragravity wave periods down to periods of a few seconds (0.004–0.2 Hz. The spectrums for the vibration amplitudes were obtained in this range and are published in this manuscript. The spectrums contain distinct resonant peaks, which corroborate the ability of resonant-like motion in suitable conditions of the forcing. The impact of local irregularities in the ice-shelf geometry to the amplitude spectrums was investigated for idealized sinusoidal perturbations of the ice surface and the sea bottom. The results of the numerical experiments presented in this manuscript, are approximately in agreement with the results obtained by the thin-plate model in the research carried out by Holdsworth and Glynn (1978. In addition, the full model allows to observe 3-D effects, for instance, vertical distribution of the stress components in the plate. In particular, the model reveals the increasing in shear stress, which is neglected in the thin-plate approximation, from the terminus towards the grounding zone with the maximum at the grounding line in the case of considered high-frequency forcing. Thus, the high-frequency forcing can reinforce the tidal impact to the ice-shelf grounding zone additionally exciting the ice fracture there.
Clochard, V.
1998-12-02
3D VSP imaging is nowadays a strategic requirement by petroleum companies. It is used to precise in details the geology close to the well. Because of the lack of redundancy and limited coverage in the data. this kind of technology is more restrictive than surface seismic which allows an investigation at a higher scale. Our contribution was to develop an elastic quantitative imagine (GRT migration) which can be applied to 3 components borehole dataset. The method is similar to the Kirchhoff migration using sophistical weighting of the seismic amplitudes. In reality. GRT migration uses pre-calculated Green functions (travel time. amplitude. polarization). The maps are obtained by 3D ray tracing (wavefront construction) in the velocity model. The migration algorithm works with elementary and independent tasks. which is useful to process different kind of dataset (fixed or moving geophone antenna). The study has been followed with validations using asymptotic analytical solution. The ability of reconstruction in 3D borehole survey has been tested in the Overthrust synthetic model. The application to a real circular 3D VSP shows various problems like velocity model building, anisotropy factor and the preprocessing (deconvolution. wave mode separation) which can destroy seismic amplitudes. An isotropic 3 components preprocessing of the whole dataset allows a better lateral reconstruction. The choice of a big migration aperture can help the reconstruction of strong geological dip in spite of migration smiles. Finally, the methodology can be applied to PS converted waves. (author)
Petit, J.L.
1997-07-21
This thesis is devoted to the inversion of VSP (vertical seismic profile) seismic data in order to determine the elastic properties of horizontally stratified media. The VSP records are computed using the full wave elastic modelling in isotropic and transversely isotropic media using Hankel transform, a finite difference scheme and an inverse Hankel transform algorithm, and the propagation equations are determined and numerically solved; the importance of considering a 3D wave propagation model instead of a 1 D one is emphasized. The theoretical VSP inverse problem is then considered, with the seismic waveform inversion set as a least-squares problem, consisting in recovering the distribution of physical parameters which minimize the misfit between calculated and observed VSP. The corresponding problem requires the knowledge of the source function
Park, Kwan Soo; Lee, Sam Sun; Huh, Kyung Hoe; Yi, Wan Jin; Heo, Min Suk; Choi, Soon Chul [Department of Oral and Maxillofacial Radiology, School of Dentistry, Seoul National University, Seoul (Korea, Republic of)
2008-06-15
To investigate the relationship between 3D bone architectural parameters and direction-related elastic moduli of cancellous bone of mandibular condyle. Two micro-pigs (Micro-pigR, PWG Genetics Korea) were used. Each pig was about 12 months old and weighing around 44 kg. 31 cylindrical bone specimen were obtained from cancellous bone of condyles for 3D analysis and measured by micro-computed tomography. Six parameters were trabecular thickness (Tb.Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI), degree of anisotropy (DA) and 3-dimensional fractal dimension (3DFD). Elastic moduli of three orthogonal directions (superiorinferior (SI), medial-lateral (ML), andterior-posterior (AP) direction) were calculated through finite element analysis. Elastic modulus of superior-inferior direction was higher than those of other directions. Elastic moduli of 3 orthogonal directions showed different correlation with 3D architectural parameters. Elastic moduli of SI and ML directions showed significant strong to moderate correlation with BV/TV, SMI and 3DFD. Elastic modulus of cancellous bone of pig mandibular condyle was highest in the SI direction and it was supposed that the change into plate-like structure of trabeculae was mainly affected by increase of trabeculae of SI and ML directions.
Embedding SAS approach into conjugate gradient algorithms for asymmetric 3D elasticity problems
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).
Barth, Andreas
2016-04-01
On January 6, 2016 the Democratic People's Republic of Korea (DPRK) carried out an announced nuclear test, which was the fourth after tests conducted in 2006, 2009, and 2013. An important task in discriminating a man-made explosion and a natural tectonic earthquake is the analysis of seismic waveforms. To determine the isotropic and non-isotropic characteristics of the detonation source, I invert long-period seismic data for the full seismic moment tensor to match the observed seismic signals by synthetic waveforms based on a 3D earth model. Here, I show that the inversion of long-period seismic data of the 2016 test reveals a clear explosive (isotropic) component combined with a significant release of shear energy by the double-couple part of the moment tensor. The short- and long-period waveforms of the recent test are very similar to the previous ones. First data show that the energy release of the recent event on long periods greater than 10 s is enlarged by 20-30% compared to the nuclear test in 2013. As shown previously, the double-couple part of the 2009 event was lower by a factor of 0.55 compared to the explosion in 2013, while the isotropic parts of the nuclear tests in 2009 and 2013 were similar (Barth, 2014). However, the recent test again shows a rather small double-couple part, indicating a lower amount of shear-energy radiation than in 2013. This highlights the importance of considering the release of shear energy in understanding near source damaging effects and the containment of nuclear explosions.
Chu, Chunlei
2009-01-01
We present two Lax‐Wendroff type high‐order time stepping schemes and apply them to solving the 3D elastic wave equation. The proposed schemes have the same format as the Taylor series expansion based schemes, only with modified temporal extrapolation coefficients. We demonstrate by both theoretical analysis and numerical examples that the modified schemes significantly improve the stability conditions.
The influence of 3d-metal alloy additions on the elastic and thermodynamic properties of CuPd3
Huang Shuo; Zhang Chuan-Hui; Sun Jing; Shen Jiang
2013-01-01
Embedded-atom method (EAM) potentials are used to investigate the effects of alloying (e.g.3d-metals) on the trends of elastic and thermodynamic properties for CuPd3 alloy.Our calculated lattice parameter,cohesive energy,and elastic constants of CuPd3 are consistent with the available experimental and theoretical data.The results of elastic constants indicate that all these alloys are mechanically stable.Further mechanical behavior analysis shows that the additions of Cr,Fe,Co,and Ni could improve the hardness of CuPd3 while V could well increase its ductility.Moreover,in order to evaluate the thermodynamic contribution of 3d-metals,the Debye temperature,phonon density of states,and vibrational entropy for CuMPd6 alloy are also investigated.
Revealing the z~2.5 Cosmic Web With 3D Lyman-Alpha Forest Tomography: A Deformation Tensor Approach
Lee, Khee-Gan
2016-01-01
Studies of cosmological objects should take into account their positions within the cosmic web of large-scale structure. Unfortunately, the cosmic web has only been extensively mapped at low-redshifts ($z1$, the required galaxy densities are inaccessible for the foreseeable future, but 3D reconstructions of Lyman-$\\alpha$ forest absorption in closely-separated background QSOs and star-forming galaxies already offer a detailed window into $z\\sim2-3$ large-scale structure. We quantify the utility of such maps for studying the cosmic web by using realistic $z=2.5$ Ly$\\alpha$ forest simulations matched to observational properties of upcoming surveys. A deformation tensor-based analysis is used to classify voids, sheets, filaments and nodes in the flux, which is compared to those determined from the underlying dark matter field. We find an extremely good correspondence, with $70\\%$ of the volume in the flux maps correctly classified relative to the dark matter web, and $99\\%$ classified to within 1 eigenvalue. Thi...
Simultaneous elastic parameter inversion in 2-D/3-D TTI medium combined later arrival times
Bai, Chao-ying; Wang, Tao; Yang, Shang-bei; Li, Xing-wang; Huang, Guo-jiao
2016-04-01
Traditional traveltime inversion for anisotropic medium is, in general, based on a "weak" assumption in the anisotropic property, which simplifies both the forward part (ray tracing is performed once only) and the inversion part (a linear inversion solver is possible). But for some real applications, a general (both "weak" and "strong") anisotropic medium should be considered. In such cases, one has to develop a ray tracing algorithm to handle with the general (including "strong") anisotropic medium and also to design a non-linear inversion solver for later tomography. Meanwhile, it is constructive to investigate how much the tomographic resolution can be improved by introducing the later arrivals. For this motivation, we incorporated our newly developed ray tracing algorithm (multistage irregular shortest-path method) for general anisotropic media with a non-linear inversion solver (a damped minimum norm, constrained least squares problem with a conjugate gradient approach) to formulate a non-linear inversion solver for anisotropic medium. This anisotropic traveltime inversion procedure is able to combine the later (reflected) arrival times. Both 2-D/3-D synthetic inversion experiments and comparison tests show that (1) the proposed anisotropic traveltime inversion scheme is able to recover the high contrast anomalies and (2) it is possible to improve the tomographic resolution by introducing the later (reflected) arrivals, but not as expected in the isotropic medium, because the different velocity (qP, qSV and qSH) sensitivities (or derivatives) respective to the different elastic parameters are not the same but are also dependent on the inclination angle.
Geodynamic background of the 2008 Wenchuan earthquake based on 3D visco-elastic numerical modelling
Liu, Chang; Zhu, Bojing; Yang, Xiaolin; Shi, Yaolin
2016-03-01
The 2008 Wenchuan earthquake (Mw7.9) occurred in the Longmen Shan fault zone. The stress change and crustal deformation during the accumulation period is computed using 3D finite element modelling assuming visco-elastic rheology. Our results support that the eastward movement of the Tibetan Plateau resulting from the India-Eurasia collision is obstructed at the Longmen Shan fault zone by the strong Yangtze craton. In response, the Tibetan ductile crust thickens and accumulates at the contact between the Tibetan Plateau and the Sichuan Basin. This process implies a strong uplift with the rate of about 1.8 mm/a of the upper crust and induces a stress concentration nearly at the bottom of the Longmen Shan fault zone. We believe that the stress concentration in the Longmen Shan fault zone provides a very important geodynamic background of the 2008 Wenchuan earthquake. Using numerical experiments we find that the key factor controlling this stress concentration process is the large viscosity contrast in the middle and lower crusts between the Tibetan Plateau and the Sichuan Basin. The results show that large viscosity contrast in the middle and lower crusts accelerates the stress concentration in the Longmen Shan fault zone. Fast moving lower crustal flow accelerates this stress accumulation process. During the inter-seismic period, spatially the maximum stress accumulation rate of the eastern margin of the Tibetan Plateau is located nearly at the bottom of the brittle upper crust of the Longmen Shan fault zone. The spatial distribution of the stress accumulation along the strike of the Longmen Shan fault zone is as follows: the normal stress decreases while the shear stress increases from southwest to northeast along the Longmen Shan fault zone. This stress distribution explains the thrust motion in the SW and strike-slip motion in the NE during the 2008 Wenchuan earthquake.
Levashov, Valentin A
2015-01-01
It is possible to associate with every atom or molecule in a liquid its own atomic stress tensor. These atomic stress tensors can be used to describe liquids' structures and to investigate the connection between structural and dynamic properties. In particular, atomic stresses allow to address atomic scale correlations relevant to the Green-Kubo expression for viscosity. Previously correlations between the atomic stresses of different atoms were studied using the Cartesian representation of the stress tensors or the representation based on spherical harmonics. In this paper we address structural correlations in a model 3D binary liquid using the eigenvalues and eigenvectors of the atomic stress tensors. Thus correlations relevant to the Green-Kubo expression for viscosity are interpreted in a simple geometric way. On decrease of temperature the changes in the relevant stress correlation function between different atoms are significantly more pronounced than the changes in the pair density function. We demonst...
Saxena, Nishank; Mavko, Gary
2016-03-01
Estimation of elastic rock moduli using 2D plane strain computations from thin sections has several numerical and analytical advantages over using 3D rock images, including faster computation, smaller memory requirements, and the availability of cheap thin sections. These advantages, however, must be weighed against the estimation accuracy of 3D rock properties from thin sections. We present a new method for predicting elastic properties of natural rocks using thin sections. Our method is based on a simple power-law transform that correlates computed 2D thin section moduli and the corresponding 3D rock moduli. The validity of this transform is established using a dataset comprised of FEM-computed elastic moduli of rock samples from various geologic formations, including Fontainebleau sandstone, Berea sandstone, Bituminous sand, and Grossmont carbonate. We note that using the power-law transform with a power-law coefficient between 0.4-0.6 contains 2D moduli to 3D moduli transformations for all rocks that are considered in this study. We also find that reliable estimates of P-wave (Vp) and S-wave velocity (Vs) trends can be obtained using 2D thin sections.
Tensor Analyzing Powers for Quasi-Elastic Electron Scattering from Deuterium
Z.-L. Zhou; M. Bouwhuis; M. Ferro-Luzzi; E. Passchier; R. Alarcon; M. Anghinolfi; H. Arenhoevel; R. van Bommel; T. Botto; J.F.J. van den Brand; H.J. Bulten; S. Choi; J. Comfort; S.M. Dolfini; R. Ent; C. Gaulard; D.W. Higinbotham; C.W. de Ja ger; E. Konstantinov; J. Lang; W. Leidemann; D.J. de Lange; M.A. Miller; D. Niko lenko; N. Papadakis; I. Passchier; H.R. Poolman; S.G. Popov; I. Rachek; M. Ripan i; E. Six; J.J.M. Steijger; M. Taiuti; O. Unal; N. Vodinas; H. de Vries
1999-01-01
We report on a first measurement of tensor analyzing powers in quasi-elastic electron-deuteron scattering at an average three-momentum transfer of 1.7 fm{sup -1}. Data sensitive to the spin-dependent nucleon density in the deuteron were obtained for missing momenta up to 150 MeV/c with a tensor polarized {sup 2}H target internal to an electron storage ring. The data are well described by a calculation that includes the effects of final-state interaction, meson-exchange and isobar currents, and leading-order relativistic contributions.
Studying conformally flat spacetimes with an elastic stress energy tensor using 1+3 formalism
Brito, I
2012-01-01
Conformally flat spacetimes with an elastic stress energy tensor given by a diagonal trace-free anisotropic pressure tensor are investigated using 1+3 formalism. We show how the null tetrad Ricci components are related to the pressure components and energy density. The 1+3 Bianchi and Jacobi identities and Einstein field equations are written for this particular case. In general the commutators must be considered since they supply potentially new information on higher order derivatives of the 1+3 quantities. We solve the system for the non rotating case which consist of ODEs of a spatial coordinate.
Integral identities for a semi-infinite interfacial crack in 2D and 3D elasticity
Piccolroaz, Andrea
2011-01-01
The paper is concerned with the problem of a semi-infinite crack at the interface between two dissimilar elastic half-spaces, loaded by a general asymmetrical system of forces distributed along the crack faces. On the basis of the weight function approach and the fundamental reciprocal identity (Betti formula), we formulate the elasticity problem in terms of singular integral equations relating the applied loading and the resulting crack opening. Such formulation is fundamental in the theory of elasticity and extensively used to solve several problems in linear elastic fracture mechanics (for instance various classic crack problems in homogeneous and heterogeneous media). This formulation is also crucial in important recent multiphysics applications, where the elastic problem is coupled with other concurrent physical phenomena. A paradigmatic example is hydraulic fracturing, where the elasticity equations are coupled with fluid dynamics.
ELATE: an open-source online application for analysis and visualization of elastic tensors.
Gaillac, Romain; Pullumbi, Pluton; Coudert, François-Xavier
2016-07-13
We report on the implementation of a tool for the analysis of second-order elastic stiffness tensors, provided with both an open-source Python module and a standalone online application allowing the visualization of anisotropic mechanical properties. After describing the software features, how we compute the conventional elastic constants and how we represent them graphically, we explain our technical choices for the implementation. In particular, we focus on why a Python module is used to generate the HTML web page with embedded Javascript for dynamical plots. PMID:27199239
ELATE: an open-source online application for analysis and visualization of elastic tensors
Gaillac, Romain; Pullumbi, Pluton; Coudert, François-Xavier
2016-07-01
We report on the implementation of a tool for the analysis of second-order elastic stiffness tensors, provided with both an open-source Python module and a standalone online application allowing the visualization of anisotropic mechanical properties. After describing the software features, how we compute the conventional elastic constants and how we represent them graphically, we explain our technical choices for the implementation. In particular, we focus on why a Python module is used to generate the HTML web page with embedded Javascript for dynamical plots.
Levine, Lyle; Okoro, Chukwudi; Lee, I-Fang; Phan, Thien; Kassner, Michael; Xu, Ruqing; Tischler, Jon; Liu, Wenjun
2014-01-01
The use of depth resolved, submicrometer X-ray beams for studying deformation microstructures in plastically deformed metals has come a long way over the past 5 years. We can identify phases, measure crystallographic orientations, and measure lattice constants from buried, submicrometer sample volumes throughout extended sample regions within single crystal and polycrystalline samples. In special cases, we can also measure both deviatoric and complete elastic strain tensors with reliable unce...
无
2010-01-01
The squirrel-cage elastic support is one of the most important components of an aero-engine rotor system.A proper structural design will favor the static and dynamic performances of the system.In view of the deficiency of the current shape optimization techniques,a new mapping approach is proposed to define shape design variables based on the parametric equations of 3D curves and surfaces.It is then applied for the slot shape optimization of a squirrel-cage elastic support.To this end,an automatic design procedure that integrates the Genetic Algorithm (GA) is developed to solve the problem.Two typical examples with different shape constraints are considered.Numerical results provide reasonable optimum designs for the improvement of stiffness and strength of the squirrel-cage elastic support.
Elasticity of 3D networks with rigid filaments and compliant crosslinks
Heidemann, Knut M; Rehfeldt, Florian; Schmidt, Christoph F; Wardetzky, Max
2014-01-01
Disordered filamentous networks with compliant crosslinks exhibit a low linear elastic shear modulus at small strains, but stiffen dramatically at high strains. Experiments have shown that the elastic modulus can increase by up to three orders of magnitude while the networks withstand relatively large stresses without rupturing. Here, we perform an analytical and numerical study on model networks in three dimensions. Our model consists of a collection of randomly oriented rigid filaments connected by flexible crosslinks that are modeled as wormlike chains. Due to zero probability of filament intersection in three dimensions, our model networks are by construction prestressed in terms of initial tension in the crosslinks. We demonstrate how the linear elastic modulus can be related to the prestress in these network. Under the assumption of affine deformations in the limit of infinite crosslink density, we show analytically that the nonlinear elastic regime in 1- and 2-dimensional networks is characterized by p...
Scheunert, M.; Ullmann, A.; Afanasjew, M.; Börner, R.-U.; Siemon, B.; Spitzer, K.
2016-06-01
We present an inversion concept for helicopter-borne frequency-domain electromagnetic (HEM) data capable of reconstructing 3-D conductivity structures in the subsurface. Standard interpretation procedures often involve laterally constrained stitched 1-D inversion techniques to create pseudo-3-D models that are largely representative for smoothly varying conductivity distributions in the subsurface. Pronounced lateral conductivity changes may, however, produce significant artifacts that can lead to serious misinterpretation. Still, 3-D inversions of entire survey data sets are numerically very expensive. Our approach is therefore based on a cut-&-paste strategy whereupon the full 3-D inversion needs to be applied only to those parts of the survey where the 1-D inversion actually fails. The introduced 3-D Gauss-Newton inversion scheme exploits information given by a state-of-the-art (laterally constrained) 1-D inversion. For a typical HEM measurement, an explicit representation of the Jacobian matrix is inevitable which is caused by the unique transmitter-receiver relation. We introduce tensor quantities which facilitate the matrix assembly of the forward operator as well as the efficient calculation of the Jacobian. The finite difference forward operator incorporates the displacement currents because they may seriously affect the electromagnetic response at frequencies above 100. Finally, we deliver the proof of concept for the inversion using a synthetic data set with a noise level of up to 5%.
Shiann-Jong Lee
2010-01-01
Full Text Available Moment tensor inversion is a routine procedure to obtain information on an earthquake source for moment magnitude and focal mechanism. However, the inversion quality is usually controlled by factors such as knowledge of an earthquake location and the suitability of a 1-D velocity model used. Here we present an improved method to invert the moment tensor solution for local earthquakes. The proposed method differs from routine centroid-moment-tensor inversion of the Broadband Array in Taiwan for Seismology in three aspects. First, the inversion is repeated in the neighborhood of an _ hypocenter on a grid basis. Second, it utilizes _ functions based on a true three-dimensional velocity model. And third, it incorporates most of the input waveforms from strong-motion records. The proposed grid-based moment tensor inversion is applied to a local earthquake that occurred near the Taipei basin on 23 October 2004 to demonstrate its effectiveness and superiority over methods used in previous studies. By using the grid-based moment tensor inversion technique and 3-D _ functions, the earthquake source parameters, including earthquake location, moment magnitude and focal mechanism, are accurately found that are sufficiently consistent with regional ground motion observations up to a frequency of 1.0 Hz. This approach can obtain more precise source parameters for other earthquakes in or near a well-modeled basin and crustal structure.
Levashov, V. A.
2016-03-01
It is possible to associate with every atom or molecule in a liquid its own atomic stress tensor. These atomic stress tensors can be used to describe liquids' structures and to investigate the connection between structural and dynamic properties. In particular, atomic stresses allow to address atomic scale correlations relevant to the Green-Kubo expression for viscosity. Previously correlations between the atomic stresses of different atoms were studied using the Cartesian representation of the stress tensors or the representation based on spherical harmonics. In this paper we address structural correlations in a 3D model binary liquid using the eigenvalues and eigenvectors of the atomic stress tensors. This approach allows to interpret correlations relevant to the Green-Kubo expression for viscosity in a simple geometric way. On decrease of temperature the changes in the relevant stress correlation function between different atoms are significantly more pronounced than the changes in the pair density function. We demonstrate that this behaviour originates from the orientational correlations between the eigenvectors of the atomic stress tensors. We also found correlations between the eigenvalues of the same atomic stress tensor. For the studied system, with purely repulsive interactions between the particles, the eigenvalues of every atomic stress tensor are positive and they can be ordered: λ1 ≥ λ2 ≥ λ3 ≥ 0. We found that, for the particles of a given type, the probability distributions of the ratios (λ2/λ1) and (λ3/λ2) are essentially identical to each other in the liquids state. We also found that λ2 tends to be equal to the geometric average of λ1 and λ3. In our view, correlations between the eigenvalues may represent "the Poisson ratio effect" at the atomic scale.
Oh, Ju-Won
2016-07-04
Multiparameter full waveform inversion (FWI) applied to an elastic orthorhombic model description of the subsurface requires in theory a nine-parameter representation of each pixel of the model. Even with optimal acquisition on the Earth surface that includes large offsets, full azimuth, and multicomponent sensors, the potential for trade-off between the elastic orthorhombic parameters are large. The first step to understanding such trade-off is analysing the scattering potential of each parameter, and specifically, its scattering radiation patterns. We investigate such radiation patterns for diffraction and for scattering from a horizontal reflector considering a background isotropic model. The radiation patterns show considerable potential for trade-off between the parameters and the potentially limited resolution in their recovery. The radiation patterns of C11, C22, and C33 are well separated so that we expect to recover these parameters with limited trade-offs. However, the resolution of their recovery represented by recovered range of model wavenumbers varies between these parameters. We can only invert for the short wavelength components (reflection) of C33 while we can mainly invert for the long wavelength components (transmission) of the elastic coefficients C11 and C22 if we have large enough offsets. The elastic coefficients C13, C23, and C12 suffer from strong trade-offs with C55, C44, and C66, respectively. The trade-offs between C13 and C55, as well as C23 and C44, can be partially mitigated if we acquire P–SV and SV–SV waves. However, to reduce the trade-offs between C12 and C66, we require credible SH–SH waves. The analytical radiation patterns of the elastic constants are supported by numerical gradients of these parameters.
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.
Force sensing using 3D displacement measurements in linear elastic bodies
Feng, Xinzeng; Hui, Chung-Yuen
2016-07-01
In cell traction microscopy, the mechanical forces exerted by a cell on its environment is usually determined from experimentally measured displacement by solving an inverse problem in elasticity. In this paper, an innovative numerical method is proposed which finds the "optimal" traction to the inverse problem. When sufficient regularization is applied, we demonstrate that the proposed method significantly improves the widely used approach using Green's functions. Motivated by real cell experiments, the equilibrium condition of a slowly migrating cell is imposed as a set of equality constraints on the unknown traction. Our validation benchmarks demonstrate that the numeric solution to the constrained inverse problem well recovers the actual traction when the optimal regularization parameter is used. The proposed method can thus be applied to study general force sensing problems, which utilize displacement measurements to sense inaccessible forces in linear elastic bodies with a priori constraints.
A 3D Orthotropic Strain-Rate Dependent Elastic Damage Material Model.
English, Shawn Allen
2014-09-01
A three dimensional orthotropic elastic constitutive model with continuum damage and cohesive based fracture is implemented for a general polymer matrix composite lamina. The formulation assumes the possibility of distributed (continuum) damage followed b y localized damage. The current damage activation functions are simply partially interactive quadratic strain criteria . However, the code structure allows for changes in the functions without extraordinary effort. The material model formulation, implementation, characterization and use cases are presented.
3D printed elastic honeycombs with graded density for tailorable energy absorption
Bates, Simon R. G.; Farrow, Ian R.; Trask, Richard S.
2016-04-01
This work describes the development and experimental analysis of hyperelastic honeycombs with graded densities, for the purpose of energy absorption. Hexagonal arrays are manufactured from thermoplastic polyurethane (TPU) via fused filament fabrication (FFF) 3D printing and the density graded by varying cell wall thickness though the structures. Manufactured samples are subject to static compression tests and their energy absorbing potential analysed via the formation of energy absorption diagrams. It is shown that by grading the density through the structure, the energy absorption profile of these structures can be manipulated such that a wide range of compression energies can be efficiently absorbed.
Energy dependence of the tensor polarisation t20 in π+-d elastic scattering
The tensor polarisation t20 of the recoil deuterons from π+-d elastic scattering has been measured between Tsub(π)=110 and 150 MeV. An excitation curve of t20 shows a clear peak near the mass 2.14 GeV with a structure 20 MeV wide. The angular distributions at 117, 134 and 151 MeV confirm the rapidly changing behaviour with energy. A phase-shift analysis of all π+-d scattering data in this energy range has been performed. The strong energy and angular dependence is believed to manifest evidence for non-conventional dynamics. (author)
Abbott, D
2000-01-01
Tensor polarization observables (t20, t21 and t22) have been measured in elastic electron-deuteron scattering for six values of momentum transfer between 0.66 and 1.7 (GeV/c)^2. The experiment was performed at the Jefferson Laboratory in Hall C using the electron HMS Spectrometer, a specially designed deuteron magnetic channel and the recoil deuteron polarimeter POLDER. The new data determine to much larger Q^2 the deuteron charge form factors G_C and G_Q. They are in good agreement with relativistic calculations and disagree with pQCD predictions.
Garçon, M; Ahmidouch, A; Anklin, H; Arvieux, J; Ball, J; Beedoe, S; Beise, E J; Bimbot, L; Böglin, W; Breuer, H; Carlini, R; Chant, N S; Danagulyan, S; Dow, K; Ducret, J E; Dunne, J; Ewell, L A; Eyraud, L; Furget, C; Gilman, R; Glashausser, C; Gueye, P; Gustafsson, K K; Hafidi, K; Honegger, A; Jourdan, J; Kox, S; Kumbartzki, G; Lü, L; Lung, A; Mack, D; Markowitz, P; McIntyre, J; Meekins, D; Merchez, F; Mitchell, J; Möhring, R H; Mtingwa, S; Mrktchyan, H; Pitz, D; Qin, L; Ransome, R; Real, J S; Roos, P G; Rutt, P; Schmidt, W; Sawafta, R; Stepanyan, S; Stephenson, E J; Tieulent, R; Tomasi-Gustafsson, E; Turchinetz, W E; Vansyoc, K; Volmer, J; Voutier, E; Vulcan, W; Williamson, C; Wood, S A; Yan, C; Zhao, J; Zhao, W
1999-01-01
In elastic electron-deuteron scattering, the tensor polarization moments t sub 2 sub 0 , t sub 2 sub 1 and t sub 2 sub 2 , together with the unpolarized cross-sections, have been measured up to a momentum transfer of 1.8 (GeV/c) sup 2 , or 6.8 fm sup - sup 1. The experiment was performed at Jefferson Laboratory using the recoil deuteron polarimeter POLDER. Preliminary results are presented and discussed, especially in view of their significance concerning the applicability of perturbative QCD to this exclusive process.
SHELL-5, Elastic Stress Analysis of 3-D Thin Shells Using Finite Elements Method
1 - Description of problem or function: SHELL5 performs an elastic stress analysis of smoothly curved, arbitrarily shaped, three- dimensional thin shells with any desired distributions of material properties, boundary constraints, and mechanical, thermal, and displacement loading conditions. 2 - Method of solution: SHELL5 uses the finite-element method to formulate a triangular plate element whose membrane displacement fields are linear polynomial functions and bending displacement field is a cubic polynomial function. The shell surface is approximated by a network of these plate elements of arbitrary orientation. Five degrees of freedom (3 displacements and 2 bending rotations) are obtained at each nodal point. The direct solution of the resulting system of equilibrium equations is obtained by the segment block tridiagonal Gaussian elimination method. 3 - Restrictions on the complexity of the problem - Maxima of: 1000 nodal points, 2000 elements, The maximum difference allowed for coupled nodal point indexes is 23
Pathak, Himanshu; Singh, Akhilendra; Singh, Indra Vir
2016-06-01
In this work, finite element method (FEM) and element free Galerkin method (EFGM) are coupled for solving 3D crack domains subjected to cyclic thermal load of constant amplitude. Crack growth contours and fatigue life have been obtained for each of the considered numerical examples. Thermo-elastic problems are decoupled into thermal and elastic problems . Firstly, the unknown temperature field is obtained by solving heat conduction equation, then, it is used as the input load in the elastic problem to calculate the displacement and stress fields. The geometrical discontinuity across crack surface is modelled by extrinsically enriched EFGM and the remaining part of the domain is approximated by standard finite element method. At the crack interface, a ramp function based interpolation scheme has been implemented. This coupled approach combines the advantages of both EFGM and FEM. A linear successive crack increment approach is used to model crack growth. The growing crack surface is traced by level set function. Standard Paris law is used for life estimation of the three-dimensional crack models. Different cases of planar and non-planar crack problems have been solved and their results are compared with the results obtained using extended finite element method to check accuracy, efficiency and robustness of the coupled FE-EFG approach implemented in this study.
Lyle E. Levine
2015-11-01
Full Text Available Nondestructive measurements of the full elastic strain and stress tensors from individual dislocation cells distributed along the full extent of a 50 µm-long polycrystalline copper via in Si is reported. Determining all of the components of these tensors from sub-micrometre regions within deformed metals presents considerable challenges. The primary issues are ensuring that different diffraction peaks originate from the same sample volume and that accurate determination is made of the peak positions from plastically deformed samples. For these measurements, three widely separated reflections were examined from selected, individual grains along the via. The lattice spacings and peak positions were measured for multiple dislocation cell interiors within each grain and the cell-interior peaks were sorted out using the measured included angles. A comprehensive uncertainty analysis using a Monte Carlo uncertainty algorithm provided uncertainties for the elastic strain tensor and stress tensor components.
Elastic and inelastic neutron scattering studies on 3d and 4f magnetic compounds
First, some theoretical aspects of neutron scattering techniques are given, and the cyrogenic equipment and the neutron spectrometers employed are described. Experiments on a 3-d Ising system are described, performed at very low temperatures and in a magnetic field. Experimental proof has been obtained for the theoretical prediction that the critical behaviour of a d-dimensional Ising system in a transverse magnetic field near T=0 is identical to that of a d+1 dimensional Ising system as a function of temperature in zero field. Experiments are described on a Ni2+ compound which represents a good example of a 1-d antiferromagnetic Heisenberg (HAF), spin s=1, system. The results give evidence for the so called 'Haldane conjecture', a theory which predicts that the ground state of HAF systems with integer spin is a nonmagnetic many-body singlet. The excited states are separated from the ground state by an energy gap. Contrastingly, half-integer spin systems are predicted to have no such gap. A short introduction is given to phenomena in rare earth, 4f compunds, like the Kondo effect and heavy fermion behaviour. Experimental results on the RE hexaborides are reported, among which CeB6, a typical Kondo system with complex magnetic orderings. Furthermore, inelastic neutron scattering experiments on NdB6 and CeB6, performed in order to get insight in the various reaction mechanisms, are presented. Finally a report is given on magnetic correlations and excitations in two nonmagnetically ordered heavy fermion compounds, CeCu6 and CeRu2Si2 and their interpretation in the light of existing theories. 201 refs.; 61 figs.; 4 tabs
Wang, S.; De Hoop, M. V.; Xia, J.; Li, X.
2011-12-01
We consider the modeling of elastic seismic wave propagation on a rectangular domain via the discretization and solution of the inhomogeneous coupled Helmholtz equation in 3D, by exploiting a parallel multifrontal sparse direct solver equipped with Hierarchically Semi-Separable (HSS) structure to reduce the computational complexity and storage. In particular, we are concerned with solving this equation on a large domain, for a large number of different forcing terms in the context of seismic problems in general, and modeling in particular. We resort to a parsimonious mixed grid finite differences scheme for discretizing the Helmholtz operator and Perfect Matched Layer boundaries, resulting in a non-Hermitian matrix. We make use of a nested dissection based domain decomposition, and introduce an approximate direct solver by developing a parallel HSS matrix compression, factorization, and solution approach. We cast our massive parallelization in the framework of the multifrontal method. The assembly tree is partitioned into local trees and a global tree. The local trees are eliminated independently in each processor, while the global tree is eliminated through massive communication. The solver for the inhomogeneous equation is a parallel hybrid between multifrontal and HSS structure. The computational complexity associated with the factorization is almost linear with the size of the Helmholtz matrix. Our numerical approach can be compared with the spectral element method in 3D seismic applications.
Assi, Hisham
2016-01-01
Numerical simulation of wave propagation in an infinite medium is made possible by surrounding a finite region by a perfectly matched layer (PML). Using this approach a generalized three-dimensional (3D) formulation is proposed for time-domain modeling of elastic wave propagation in an unbounded lossless anisotropic medium. The formulation is based on a second-order approach that has the advantages of, physical relationship to the underlying equations, and amenability to be implemented in common numerical schemes. Specifically, our formulation uses three second-order equations of the displacement field and nine auxiliary equations, along with the three time histories of the displacement field. The properties of the PML, which are controlled by a complex two-parameter stretch function, are such that it acts as near perfect absorber. Using finite element method (FEM) 3D numerical results are presented for a highly anisotropic medium. An extension of the formulation to the particular case of a Kelvin-Vogit visco...
Revealing the z~2.5 Cosmic Web With 3D Lyman-Alpha Forest Tomography: A Deformation Tensor Approach
Lee, Khee-Gan; White, Martin
2016-01-01
Studies of cosmological objects should take into account their positions within the cosmic web of large-scale structure. Unfortunately, the cosmic web has only been extensively mapped at low-redshifts ($z1$, the required galaxy densities are inaccessible for the foreseeable future, but 3D reconstructions of Lyman-$\\alpha$ forest absorption in closely-separated background QSOs and star-forming galaxies already offer a detailed window into $z\\sim2-3$ large-scale structure. We quantify the utili...
Borisov, Dmitry; Singh, Satish C.; Fuji, Nobuaki
2015-09-01
Seismic full waveform inversion is an objective method to estimate elastic properties of the subsurface and is an important area of research, particularly in seismic exploration community. It is a data-fitting approach, where the difference between observed and synthetic data is minimized iteratively. Due to a very high computational cost, the practical implementation of waveform inversion has so far been restricted to a 2-D geometry with different levels of physics incorporated in it (e.g. elasticity/viscoelasticity) or to a 3-D geometry but using an acoustic approximation. However, the earth is three-dimensional, elastic and heterogeneous and therefore a full 3-D elastic inversion is required in order to obtain more accurate and valuable models of the subsurface. Despite the recent increase in computing power, the application of 3-D elastic full waveform inversion to real-scale problems remains quite challenging on the current computer architecture. Here, we present an efficient method to perform 3-D elastic full waveform inversion for time-lapse seismic data using a finite-difference injection method. In this method, the wavefield is computed in the whole model and is stored on a surface above a finite volume where the model is perturbed and localized inversion is performed. Comparison of the final results using the 3-D finite-difference injection method and conventional 3-D inversion performed within the whole volume shows that our new method provides significant reductions in computational time and memory requirements without any notable loss in accuracy. Our approach shows a big potential for efficient reservoir monitoring in real time-lapse experiments.
Martin, O. J. F.; Gay-Balmaz, P.
2002-01-01
We describe a library to compute various types of Green's tensor for three-dimensional electromagnetic scattering calculations. This library includes the retarded and non-retarded (quasi-static) Green's tensors for infinite homogeneous space and the non-retarded Green's tensor associated with a surface. Both standard and filtered Green's tensor can be computed. Filtered Green's tensor can be used to accurately investigate high permittivity scatterers with the coupled-dipole approximation. (C)...
Liu, Xiaolong; Eckert, Andreas; Connolly, Peter
2016-06-01
Buckle folds of sedimentary strata commonly feature a variety of different fracture sets. Some fracture sets including outer arc tensile fractures and inner arc shear fractures at the fold hinge zones are well understood by the extensional and compressional strain/stress pattern. However, other commonly observed fracture sets, including tensile fractures parallel to the fold axis, tensile fractures cutting through the limb, extensional faults at the fold hinge, and other shear fractures of various orientations in the fold limb, fail to be intuitively explained by the strain/stress regimes during the buckling process. To obtain a better understanding of the conditions for the initiation of the various fractures sets associated with single-layer cylindrical buckle folds, a 3D finite element modeling approach using a Maxwell visco-elastic rheology is utilized. The influences of three model parameters with significant influence on fracture initiation are considered: burial depth, viscosity, and permeability. It is concluded that these parameters are critical for the initiation of major fracture sets at the hinge zone with varying degrees. The numerical simulation results further show that the buckling process fails to explain most of the fracture sets occurring in the limb unless the process of erosional unloading as a post-fold phenomenon is considered. For fracture sets that only develop under unrealistic boundary conditions, the results demonstrate that their development is realistic for a perclinal fold geometry. In summary, a more thorough understanding of fractures sets associated with buckle folds is obtained based on the simulation of in-situ stress conditions during the structural development of buckle folds.
Full text: Due to its low yield, the mb 3.9 North Korean nuclear test on 9 October 2006 could not be verified undoubtedly using solely seismic methods. The low signal-to-noise ratio (SNR) limits conventional discrimination methods such as P/S amplitude-ratios, and thus we perform a moment tensor inversion (MTI) to estimate the explosive (isotropic) component of the event. Long-period recordings are mainly controlled by the seismic source mechanism, while at shorter periods variations of the crustal structure have a stronger influence on the waveforms. On the other hand, long periods have a lower SNR than shorter periods. To obtain a good SNR for source-sensitive periods, we use an intermediate pass-band (T = 10-50 s) and include a regional 3D velocity structure deduced from the Crust 2.0 model to calculate synthetic waveforms. We study the influence of the crustal model on the inversion result using regional recordings with source-receiver distances up to 3000 km and compare the results with a tectonic mb 4.0 event that occurred in a distance of 34 km on 16 April 2002. We observe a higher isotropic part (Miso) for the nuclear test compared to the tectonic event. However, the absolute value of Miso cannot be determined because a trade-off with the inversion damping exists. To study the influence of seismic noise on Miso, we add artificial noise to the recordings of the tectonic event. Compared with the MTI of the original data we also find an increased Miso, but with other dependencies on the damping compared to the nuclear explosion data. We show trade-off curves of damping versus model length (as a function of MW) that can be a helpful tool for a timely verification of nuclear tests. (author)
Gao, Yurui; Parvathaneni, Prasanna; Schilling, Kurt G.; Wang, Feng; Stepniewska, Iwona; Xu, Zhoubing; Choe, Ann S.; Ding, Zhaohua; Gore, John C.; Chen, Li min; Landman, Bennett A.; Anderson, Adam W.
2016-03-01
Modern magnetic resonance imaging (MRI) brain atlases are high quality 3-D volumes with specific structures labeled in the volume. Atlases are essential in providing a common space for interpretation of results across studies, for anatomical education, and providing quantitative image-based navigation. Extensive work has been devoted to atlas construction for humans, macaque, and several non-primate species (e.g., rat). One notable gap in the literature is the common squirrel monkey - for which the primary published atlases date from the 1960's. The common squirrel monkey has been used extensively as surrogate for humans in biomedical studies, given its anatomical neuro-system similarities and practical considerations. This work describes the continued development of a multi-modal MRI atlas for the common squirrel monkey, for which a structural imaging space and gray matter parcels have been previously constructed. This study adds white matter tracts to the atlas. The new atlas includes 49 white matter (WM) tracts, defined using diffusion tensor imaging (DTI) in three animals and combines these data to define the anatomical locations of these tracks in a standardized coordinate system compatible with previous development. An anatomist reviewed the resulting tracts and the inter-animal reproducibility (i.e., the Dice index of each WM parcel across animals in common space) was assessed. The Dice indices range from 0.05 to 0.80 due to differences of local registration quality and the variation of WM tract position across individuals. However, the combined WM labels from the 3 animals represent the general locations of WM parcels, adding basic connectivity information to the atlas.
Petrov, P.; Newman, G. A.
2010-12-01
-Fourier domain we had developed 3D code for full-wave field simulation in the elastic media which take into account nonlinearity introduced by free-surface effects. Our approach is based on the velocity-stress formulation. In the contrast to conventional formulation we defined the material properties such as density and Lame constants not at nodal points but within cells. This second order finite differences method formulated in the cell-based grid, generate numerical solutions compatible with analytical ones within the range errors determinate by dispersion analysis. Our simulator will be embedded in an inversion scheme for joint seismic- electromagnetic imaging. It also offers possibilities for preconditioning the seismic wave propagation problems in the frequency domain. References. Shin, C. & Cha, Y. (2009), Waveform inversion in the Laplace-Fourier domain, Geophys. J. Int. 177(3), 1067- 1079. Shin, C. & Cha, Y. H. (2008), Waveform inversion in the Laplace domain, Geophys. J. Int. 173(3), 922-931. Commer, M. & Newman, G. (2008), New advances in three-dimensional controlled-source electromagnetic inversion, Geophys. J. Int. 172(2), 513-535. Newman, G. A., Commer, M. & Carazzone, J. J. (2010), Imaging CSEM data in the presence of electrical anisotropy, Geophysics, in press.
De Silva, R. T.; Pasbakhsh, Pooria; Goh, K. L.;
2014-01-01
A real-structure based 3-D micromechanical computational model of poly (lactic acid) nanocomposites reinforced by randomly oriented halloysite nanotubes (HNTs) was developed and compared with an idealized model (conventional model) and experimental results. The developed idealized model consists of...
3D tensor tractography (DTT) has been applied to central nervous system (CNS) diseases to depict neuronal fibers. In this study with 3 tesla MRI, we have evaluated DTT to predict outcome of motor function in patients with lacunar infarcts. Fifteen patients with New lacunar infarcts, underwent DTTs with at least one in the acute (mean 1.4 days) and another in the subacute phase (mean 18.7 days). Patients were separated to 2 groups, recovery and non-recovery. Patients in former group had almost complete recovery in motor function 3 month later, while those to latter had a residual hemiparesis. Motor function was assessed with MMT score, which was uniquely stratefied into 12 levels by a modified MMT (manual muscle testing) protocol. DTT was implemented with 3 tesla MRI (Signa Excite; GE) and analyzed with dTV. IISR which was produced by the Department of Radiology, Tokyo University. The pyramidal tract was delineated by setting each region of interest (ROI), with the cerebral peduncle as the seed point and the motor cortex as the target point. The number of pyramidal fibers was identified as drawn lines obtained from a result display. The ratio of the number of fibers (RF) was calculated based on the number of fibers in the injured side relative to the number of fibers in the intact side x 100. In acute phase mean RFs the recovery (70.8±21.6%) and non-recovery (63.5±23.4%) groups were not significantly different. RF of recovery group in subacute phase was 100.5±28.3%, which was significantly higher with that in acute phase, meanwhile there was no significance difference between RFs of non-recovery group in two phases. In addition there was a significant correlation (R2=0.89) between MMT score 3 month later and RF in subacute phase in all patients group. There seems to be a correlation between long-term recovery of motor function and increased numbers in pyramidal fibers defected by DTT. Therefore, DTT may have a potential use in predicting the outcome of patients
Morita, Yasuyuki; Kawase, Naoki; Ju, Yang; Yamauchi, Takashi
2016-07-01
Cells maintain homeostasis and perform various functions by interacting mechanically with a cell-adhesive matrix. Regarding cellular differentiation, it has been found that matrix elasticity can determine the differentiation lineage of mesenchymal stem cells (MSCs). Direct quantitative measurements of the mechanical interaction between MSCs and matrix for differentiation, however, have yet to be reported. Herein, the displacement field of the cell-adhesive matrix was observed quantitatively using a digital volume correlation (DVC) method. Maximum displacement and cellular traction stress were analyzed when the MSC differentiated into a neuron-like cell or an osteoblast-like cell on a soft or hard elastic matrix, respectively. The function of non-muscle myosin II (NMM II), which plays an important role in intracellular cytoskeletal dynamics, was investigated during cellular differentiation. The mechanical interaction (maximum displacement and subjected area of the matrix) between the cell and matrix was dependent on matrix elasticity. It has also been shown that the mechanical interaction between the intracellular cytoskeleton and cell-adhesion matrix is indispensable for cellular differentiation. This work provides the first quantitative visualization of the mechanical interaction between MSCs and the cell-adhesion matrix for differentiation. PMID:26945874
Levashov, Valentin A.
2015-01-01
It is possible to associate with every atom or molecule in a liquid its own atomic stress tensor. These atomic stress tensors can be used to describe liquids' structures and to investigate the connection between structural and dynamic properties. In particular, atomic stresses allow to address atomic scale correlations relevant to the Green-Kubo expression for viscosity. Previously correlations between the atomic stresses of different atoms were studied using the Cartesian representation of t...
Obermann, Anne; Planès, Thomas; Hadziioannou, Céline; Campillo, Michel
2016-07-01
In the context of seismic monitoring, recent studies made successful use of seismic coda waves to locate medium changes on the horizontal plane. Locating the depth of the changes, however, remains a challenge. In this paper, we use 3-D wavefield simulations to address two problems: firstly, we evaluate the contribution of surface and body wave sensitivity to a change at depth. We introduce a thin layer with a perturbed velocity at different depths and measure the apparent relative velocity changes due to this layer at different times in the coda and for different degrees of heterogeneity of the model. We show that the depth sensitivity can be modelled as a linear combination of body- and surface-wave sensitivity. The lapse-time dependent sensitivity ratio of body waves and surface waves can be used to build 3-D sensitivity kernels for imaging purposes. Secondly, we compare the lapse-time behavior in the presence of a perturbation in horizontal and vertical slabs to address, for instance, the origin of the velocity changes detected after large earthquakes.
This technical note demonstrates the relevance of the isotropic 3D T2 turbo-spin-echo (TSE) sequence with short-term inversion recovery (STIR) and variable flip angle RF excitations (SPACE: Sampling Perfection with Application optimized Contrasts using different flip angle Evolutions) for high-resolution brachial plexus imaging. The sequence was used in 11 patients in the diagnosis of brachial plexus pathologies involving primary and secondary tumors, and in six volunteers. We show that 3D STIR imaging is not only a reliable alternative to 2D STIR imaging, but it also better evaluates the anatomy, nerve site compression and pathology of the plexus, especially to depict space-occupying tumors along its course. Finally, due to its appropriate contrast we describe how 3D-STIR can be used as a high-resolution mask to be fused with fraction of anisotropy (FA) maps calculated from diffusion tensor imaging (DTI) data of the plexus. (orig.)
Viallon, M.; Vargas, M.I.; Jlassi, H.; Loevblad, K.O.; Delavelle, J. [University Hospital of Geneva, Department of Radiology, Geneva (Switzerland)
2008-05-15
This technical note demonstrates the relevance of the isotropic 3D T2 turbo-spin-echo (TSE) sequence with short-term inversion recovery (STIR) and variable flip angle RF excitations (SPACE: Sampling Perfection with Application optimized Contrasts using different flip angle Evolutions) for high-resolution brachial plexus imaging. The sequence was used in 11 patients in the diagnosis of brachial plexus pathologies involving primary and secondary tumors, and in six volunteers. We show that 3D STIR imaging is not only a reliable alternative to 2D STIR imaging, but it also better evaluates the anatomy, nerve site compression and pathology of the plexus, especially to depict space-occupying tumors along its course. Finally, due to its appropriate contrast we describe how 3D-STIR can be used as a high-resolution mask to be fused with fraction of anisotropy (FA) maps calculated from diffusion tensor imaging (DTI) data of the plexus. (orig.)
Bending analysis of a general cross-ply laminate using 3D elasticity solution and layerwise theory
Yazdani Sarvestani, H.; Naghashpour, A.; Heidari-Rarani, M.
2015-12-01
In this study, the analytical solution of interlaminar stresses near the free edges of a general (symmetric and unsymmetric layups) cross-ply composite laminate subjected to pure bending loading is presented based on Reddy's layerwise theory (LWT) for the first time. First, the reduced form of displacement field is obtained for a general cross-ply composite laminate subjected to a bending moment by elasticity theory. Then, first-order shear deformation theory of plates and LWT is utilized to determine the global and local deformation parameters appearing in the displacement fields, respectively. One of the main advantages of the developed solution based on the LWT is exact prediction of interlaminar stresses at the boundary layer regions. To show the accuracy of this solution, three-dimensional elasticity bending problem of a laminated composite is solved for special set of boundary conditions as well. Finally, LWT results are presented for edge-effect problems of several symmetric and unsymmetric cross-ply laminates under the bending moment. The obtained results indicate high stress gradients of interlaminar stresses near the edges of laminates.
Gras, Renaud
2015-03-01
Performing a single but complex mechanical test on small structures rather than on coupons to probe multiple strain states/histories for identification purposes is nowadays possible thanks to full-field measurements. The aim is to identify many parameters thanks to the heterogeneity of mechanical fields. Such an approach is followed herein, focusing on a blade root made of 3D woven composite. The performed test, which is analyzed using global Digital Image Correlation (DIC), provides heterogeneous kinematic fields due to the particular shape of the sample. This displacement field is further processed to identify the four in-plane material parameters of the macroscopic equivalent orthotropic behavior. The key point, which may limit the ability to draw reliable conclusions, is the presence of acquisition noise in the original images that has to be tracked along the DIC/identification processing to provide uncertainties on the identified parameters. A further regularization based on a priori knowledge is finally introduced to compensate for possible lack of experimental information needed for completing the identification.
The source mechanisms of microseismics in hydraulic fracturing present guiding significance to the research on source types, crustal stress analysis and crack prediction. Numerical simulations based on various source mechanisms can be used to investigate the stress characteristics and response characteristics of different source types. In this paper, a method based on the seismic moment tensor (SMT) and elastic wave equation (EWE) was presented for forward modeling. Additionally, we have given the expressions of nine couples of force which can be combined into different kinds of source types. The calculations of wave fields and records with three basic types of sources showed the features in homogeneous isotropic and anisotropic media by the finite-difference (FD) method. Lastly, analysis of the relationship between the polarizing angle and incident angle provided us with some evidence to distinguish the type of media in single media. The work offers methods of instruction for identification and interpretation in microseismic monitoring. (paper)
Ju Wei; Sun Weifeng; Ma Xiaojing; Jiang Hui
2016-07-01
Future earthquake potential in the Bohai–Zhangjiakou Seismotectonic Zone (BZSZ) in North Chinadeserves close attention. Tectonic stress accumulation state is an important indicator for earthquakes;therefore, this study aims to analyse the stress accumulation state in the BZSZ via three-dimensionalvisco-elastic numerical modelling. The results reveal that the maximum shear stress in the BZSZ increasesgradually as the depth increases, and the stress range is wider in the lower layer. In the upper layer, themaximum shear stress is high in the Zhangjiakou area, whereas in the lower layer, relatively high valuesoccur in the Penglai–Yantai area, which may be affected by the depth of the Moho surface. Besides,weak fault zones will be easily fractured when the maximum shear stress is not sufficiently high due totheir low strengths, resulting in earthquakes. Therefore, based on the modelling results, the upper layerof the Zhangjiakou area and the lower layer of the Penglai–Yantai area in the BZSZ in North China aremore likely to experience earthquakes.
Ha, Jiho; Shin, Sungryul; Shin, Changsoo; Chung, Wookeen
2015-05-01
Because complex mixed waves are typically generated in elastic media, wavefield decomposition is required for such media to obtain migration images accurately. In isotropic media, this is achieved according to the Helmholtz decomposition theorem; in particular, the divergence operator is commonly applied to P-wavefield decomposition. In this study, two types of elastic reverse-time migration algorithms are proposed for decomposition of the P-wavefield without requiring the divergence operator. The first algorithm involves formulation of the stress tensor by spatially differentiated displacement according to the stress-strain relationship and is utilized to construct an imaging condition for the decomposed P-wavefield. We demonstrate this approach through numerical testing. The second algorithm allows us to obtain emphasized interfaces through the application of the absolute value function to decomposed wavefield in imaging condition. Because reverse-time migration can be defined by a zero-lag cross-correlation relationship between the partial-derivative wavefield and the observed wavefield data, we derive the virtual source to construct the partial-derivative wavefield based on a 2D staggered-grid finite-difference modeling method in the time domain. The explicitly computed partial-derivative wavefield from virtual sources with the stress tensor is in agreement with the partial-derivative wavefield directly computed from residual by between with and without a perturbation point in the subsurface. Moreover, the back-propagation technique is used to enhance the computational efficiency. To validate our two types of imaging conditions, numerical tests are conducted. The migration images created according to our imaging conditions can represent the subsurface structure accurately. Thus, we can confirm the feasibility of obtaining migration images of the decomposed P-wavefield without requiring the application of the divergence operator.
Bignardi, S.; Mantovani, A.; Abu Zeid, N.
2016-08-01
OpenHVSR is a computer program developed in the Matlab environment, designed for the simultaneous modeling and inversion of large Horizontal-to-Vertical Spectral Ratio (HVSR or H/V) datasets in order to construct 2D/3D subsurface models (topography included). The program is designed to provide a high level of interactive experience to the user and still to be of intuitive use. It implements several effective and established tools already present in the code ModelHVSR by Herak (2008), and many novel features such as: -confidence evaluation on lateral heterogeneity -evaluation of frequency dependent single parameter impact on the misfit function -relaxation of Vp/Vs bounds to allow for water table inclusion -a new cost function formulation which include a slope dependent term for fast matching of peaks, which greatly enhances convergence in case of low quality HVSR curves inversion -capability for the user of editing the subsurface model at any time during the inversion and capability to test the changes before acceptance. In what follows, we shall present many features of the program and we shall show its capabilities on both simulated and real data. We aim to supply a powerful tool to the scientific and professional community capable of handling large sets of HSVR curves, to retrieve the most from their microtremor data within a reduced amount of time and allowing the experienced scientist the necessary flexibility to integrate into the model their own geological knowledge of the sites under investigation. This is especially desirable now that microtremor testing has become routinely used. After testing the code over different datasets, both simulated and real, we finally decided to make it available in an open source format. The program is available by contacting the authors.
Ichimura, Tsuyoshi; Agata, Ryoichiro; Hori, Takane; Hirahara, Kazuro; Hashimoto, Chihiro; Hori, Muneo; Fukahata, Yukitoshi
2016-07-01
As a result of the accumulation of high-resolution observation data, 3-D high-fidelity crustal structure data for large domains are becoming available. However, it has been difficult to use such data to perform elastic/viscoelastic crustal deformation analyses in large domains with quality assurance of the numerical simulation that guarantees convergence of the numerical solution with respect to the discretization size because the costs of analysis are significantly high. This paper proposes a method of constructing a high-fidelity crustal structure finite element (FE) model using high-fidelity crustal structure data and fast FE analysis to reduce the costs of analysis (based on automatic FE model generation for parallel computation, OpenMP/MPI hybrid parallel computation on distributed memory computers, a geometric multigrid, variable preconditioning and multiple precision arithmetic). Using the proposed methods, we construct 10 billion degree-of-freedom high-fidelity crustal structure FE models for the entire Japan, and conduct elastic/viscoelastic crustal deformation analysis using this model with enough high accuracy of the numerical simulation.
Jechumtálová, Zuzana; Bulant, P.
Prague : Charles University, 2012, s. 17-27 R&D Projects: GA ČR GAP210/10/1728 Institutional support: RVO:67985530 Keywords : ray tracing * 3-D velocity model * earthquake mechanism * amplitude inversion Subject RIV: DC - Siesmology, Volcanology, Earth Structure
Jechumtálová, Zuzana; Bulant, P.
Prague : Charles University, 2013, s. 253-269 R&D Projects: GA ČR GAP210/10/1728 Institutional support: RVO:67985530 Keywords : ray tracing * 3-D velocity model * earthquake mechanism * amplitude inversion Subject RIV: DC - Siesmology, Volcanology, Earth Structure
Jechumtálová, Zuzana; Bulant, P.
2014-01-01
Roč. 18, č. 3 (2014), s. 511-531. ISSN 1383-4649 R&D Projects: GA ČR GAP210/10/1728 EU Projects: European Commission(XE) 230669 - AIM Institutional support: RVO:67985530 Keywords : ray tracing * 1-D and 3-D velocity models * earthquake mechanism * amplitude inversion * Dobrá Voda earthquakes Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.386, year: 2014
We present a newly developed combined scanning particle tracking velocimetry (SPTV) and scanning laser-induced fluorescence (SLIF) technique. The new method allows for the first time to measure the full velocity gradient tensor and the three-dimensional density field simultaneously in a refractive index matched environment. The data thus obtained will be valuable in investigating the interaction between turbulence, i.e. the dynamics of vorticity and strain, and the density field. In this study, we describe the implementation of the measurement system in detail. As a showcase, the new technique is applied to a gravity current flow and the measured data are validated by imposing various checks. Further results are presented that illustrate the capability of the SPTV/SLIF technique in the investigation of interface dynamics. (paper)
3D Face Recognition Using Facial Curves Elastic Matching%基于面部曲线弹性匹配的三维人脸识别方法
潘仁林; 达飞鹏; 邹红艳; 王朝阳
2014-01-01
提出一种基于面部径向曲线弹性匹配的三维人脸识别方法。使用人脸曲面上的多条曲线表征人脸曲面，提取三维人脸上从鼻尖点发射的多条面部径向曲线，对其进行分层弹性匹配和点距对应匹配，根据人脸不同部位受表情影响程度不同，对不同曲线识别相似度赋予不同权重进行加权融合作为总相似度用于识别。测试结果表明该方法具有很好的识别性能，并且对表情、遮挡和噪声具有较好的鲁棒性。%A 3D face recognition algorithm based on facial curves elastic matching is presented in this paper. Facial surfaces are approximated with indexed sets of level curves. Firstly, the radial curves emanating from the nose tip are extracted after 3D faces are preprocessed. Secondly, the curves of the probe face match the curves of gallery face using the improved hierarchical matching method and the two curves are matched exploiting the distance between the point and nose tip. Finally, the similarities of different curves are weighted fused according to the different degree influenced by expression as sum similarity which is used for matching. Experiment results verify that the proposed method can obtain better recognition rate, and is robust to occlusion, spikes and expression.
Zhou, Li; Zhang, Wei; Shen, Yang; Chen, Xiaofei; Zhang, Jie
2016-06-01
With dense seismic arrays and advanced imaging methods, regional three-dimensional (3D) Earth models have become more accurate. It is now increasingly feasible and advantageous to use a 3D Earth model to better locate earthquakes and invert their source mechanisms by fitting synthetics to observed waveforms. In this study, we develop an approach to determine both the earthquake location and source mechanism from waveform information. The observed waveforms are filtered in different frequency bands and separated into windows for the individual phases. Instead of picking the arrival times, the traveltime differences are measured by cross-correlation between synthetic waveforms based on the 3D Earth model and observed waveforms. The earthquake location is determined by minimizing the cross-correlation traveltime differences. We then fix the horizontal location of the earthquake and perform a grid search in depth to determine the source mechanism at each point by fitting the synthetic and observed waveforms. This new method is verified by a synthetic test with noise added to the synthetic waveforms and a realistic station distribution. We apply this method to a series of M W3.4-5.6 earthquakes in the Longmenshan fault (LMSF) zone, a region with rugged topography between the eastern margin of the Tibetan plateau and the western part of the Sichuan basin. The results show that our solutions result in improved waveform fits compared to the source parameters from the catalogs we used and the location can be better constrained than the amplitude-only approach. Furthermore, the source solutions with realistic topography provide a better fit to the observed waveforms than those without the topography, indicating the need to take the topography into account in regions with rugged topography.
Applications of tensor analysis
McConnell, A J
2011-01-01
Standard work applies tensorial methods to subjects within realm of advanced college mathematics. Text explains fundamental ideas and notation of tensor theory; covers geometrical treatment of tensor algebra; introduces theory of differentiation of tensors; and applies mathematics to dynamics, electricity, elasticity and hydrodynamics. 685 exercises, most with answers.
Erba, Alessandro
2016-05-18
Symmetry features of the internal-strain tensor of crystals (whose components are mixed second-energy derivatives with respect to atomic displacements and lattice strains) are formally presented, which originate from translational-invariance, atomic equivalences, and atomic invariances. A general computational scheme is devised, and implemented into the public Crystal program, for the quantum-mechanical evaluation of the internal-strain tensor of crystals belonging to any space-group, which takes full-advantage of the exploitation of these symmetry-features. The gain in computing time due to the full symmetry exploitation is documented to be rather significant not just for high-symmetry crystalline systems such as cubic, hexagonal or trigonal, but also for low-symmetry ones such as monoclinic and orthorhombic. The internal-strain tensor is used for the evaluation of the nuclear relaxation term of the fourth-rank elastic and third-rank piezoelectric tensors of crystals, where, apart from a reduction of the computing time, the exploitation of symmetry is documented to remarkably increase the numerical precision of computed coefficients. PMID:27150599
Combinatorial 3D Mechanical Metamaterials
Coulais, Corentin; Teomy, Eial; de Reus, Koen; Shokef, Yair; van Hecke, Martin
2015-03-01
We present a class of elastic structures which exhibit 3D-folding motion. Our structures consist of cubic lattices of anisotropic unit cells that can be tiled in a complex combinatorial fashion. We design and 3d-print this complex ordered mechanism, in which we combine elastic hinges and defects to tailor the mechanics of the material. Finally, we use this large design space to encode smart functionalities such as surface patterning and multistability.
Deuteron tensor and vector analyzing powers have been measured for the first time in p-d vector elastic scattering at 800 MeV proton laboratory energy for a-t range between 0.032 and 1.038 (GeV/c)2. The data provide a very sensitive test of the multiple scattering theory at intermediate energies. The inclusion of the noneikonal correction in the Glauber diffraction theory is essential in the description of the data, especially for-t approx. >= 0.2(GeV/c)2, where discrepancies of up to 150% are observed with the theory based on the eikonal approximation. (orig.)
Soutas-Little, Robert William
2010-01-01
According to the author, elasticity may be viewed in many ways. For some, it is a dusty, classical subject . . . to others it is the paradise of mathematics."" But, he concludes, the subject of elasticity is really ""an entity itself,"" a unified subject deserving comprehensive treatment. He gives elasticity that full treatment in this valuable and instructive text. In his preface, Soutas-Little offers a brief survey of the development of the theory of elasticity, the major mathematical formulation of which was developed in the 19th century after the first concept was proposed by Robert Hooke
Ivankina, T. I.; Kern, H.; Lokajíček, Tomáš; Nikitin, A. N.
s. l. : European Seismological Comission, 2010. ---. [European Seismological Comission General Assembly /32./. 06.09.2010-10.09.2010, Montpellier] R&D Projects: GA AV ČR IAA300130906 Institutional research plan: CEZ:AV0Z30130516 Keywords : Fine-grained biotite gneiss * neutron diffraction * elastic anisotropy lattice preferred orientation * shape preferred orientation Subject RIV: DC - Siesmology, Volcanology, Earth Structure
Tensorial analysis of Eshelby stresses in 3D supercooled liquids
Lemaître, Anaël
2015-10-01
It was recently proposed that the local rearrangements governing relaxation in supercooled liquids impress on the liquid medium long-ranged (Eshelby) stress fluctuations that accumulate over time. From this viewpoint, events must be characterized by elastic dipoles, which are second order tensors, and Eshelby fields are expected to show up in stress and stress increment correlations, which are fourth order tensor fields. We construct here an analytical framework that permits analyzing such tensorial correlations in isotropic media in view of accessing Eshelby fields. Two spherical bases are introduced, which correspond to Cartesian and spherical coordinates for tensors. We show how they can be used to decompose stress correlations and thus test such properties as isotropy and power-law scalings. Eshelby fields and the predicted stress correlations in an infinite medium are shown to belong to an algebra that can conveniently be described using the spherical tensor bases. Using this formalism, we demonstrate that the inherent stress field of 3D supercooled liquids is power law correlated and carries the signature of Eshelby fields, thus supporting the idea that relaxation events give rise to Eshelby stresses that accumulate over time.
Tensorial analysis of Eshelby stresses in 3D supercooled liquids.
Lemaître, Anaël
2015-10-28
It was recently proposed that the local rearrangements governing relaxation in supercooled liquids impress on the liquid medium long-ranged (Eshelby) stress fluctuations that accumulate over time. From this viewpoint, events must be characterized by elastic dipoles, which are second order tensors, and Eshelby fields are expected to show up in stress and stress increment correlations, which are fourth order tensor fields. We construct here an analytical framework that permits analyzing such tensorial correlations in isotropic media in view of accessing Eshelby fields. Two spherical bases are introduced, which correspond to Cartesian and spherical coordinates for tensors. We show how they can be used to decompose stress correlations and thus test such properties as isotropy and power-law scalings. Eshelby fields and the predicted stress correlations in an infinite medium are shown to belong to an algebra that can conveniently be described using the spherical tensor bases. Using this formalism, we demonstrate that the inherent stress field of 3D supercooled liquids is power law correlated and carries the signature of Eshelby fields, thus supporting the idea that relaxation events give rise to Eshelby stresses that accumulate over time. PMID:26520535
Zhang, Mian; Huang, Cheng-li
2012-08-01
Generalized spherical harmonics (GSH) are usually applied on the problems where the Earth model is elliptical and elastic stress tensor is involved in, as stress tensor can’t be represented in vector spherical harmonics. However, the divergence of the te ns or and a vector dot - product with the tensor are only needed on computation rotation modes of the Earth which can be written in the vector spherical harmonics. We extend the equations on the spherical Earth to asymmetric 3D model by means of linear operator method. This method doesn’t use the complicated generalized spherical harmonics nor Wigner 3 - j symbol. As a validation of this method, the practical calculation of rotational modes of 3D Earth will be made and discussed.
Ichimura, Tsuyoshi; Agata, Ryoichiro; Hori, Takane; Hirahara, Kazuro; Hashimoto, Chihiro; Hori, Muneo; Fukahata, Yukitoshi
2016-04-01
As a result of the accumulation of high-resolution observation data, three-dimensional high-fidelity crustal structure data for large domains are becoming available. However, it has been difficult to use such data to perform elastic/viscoelastic crustal deformation analyses in large domains with quality assurance of the numerical simulation that guarantees convergence of the numerical solution with respect to the discretisation size, because the costs of analysis are significantly high. This paper proposes a method of constructing a high-fidelity crustal structure finite element (FE) model using high-fidelity crustal structure data and fast FE analysis to reduce the costs of analysis (based on automatic FE model generation for parallel computation, OpenMP/MPI hybrid parallel computation on distributed memory computers, a geometric multigrid, variable preconditioning, and multiple precision arithmetic). Using the proposed methods, we construct 10 billion degree-of-freedom high-fidelity crustal structure FE models for the entire Japan, and conduct elastic/viscoelastic crustal deformation analysis using this model with enough high accuracy of the numerical simulation.
Thizy, C.; Eliot, F.; Ballhause, D.; Olympio, K. R.; Kluge, R.; Shannon, A.; Laduree, G.; Logut, D.; Georges, M. P.
2013-04-01
Thermo-elastic distortions of composite structures have been measured by a holographic camera using a BSO photorefractive crystal as the recording medium. The first test campaign (Phase 1) was performed on CFRP struts with titanium end-fittings glued to the tips of the strut. The samples were placed in a vacuum chamber. The holographic camera was located outside the chamber and configured with two illuminations to measure the relative out-of-plane and in-plane (in one direction) displacements. The second test campaign (Phase 2) was performed on a structure composed of a large Silicon Carbide base plate supported by 3 GFRP struts with glued Titanium end-fittings. Thermo-elastic distortions have been measured with the same holographic camera used in phase 1, but four illuminations, instead of two, have been used to provide the three components of displacement. This technique was specially developed and validated during the phase 2 in CSL laboratory. The system has been designed to measure an object size of typically 250x250 mm2; the measurement range is such that the sum of the largest relative displacements in the three measurement directions is maximum 20 μm. The validation of the four-illuminations technique led to measurement uncertainties of 120 nm for the relative in-plane and out-of-plane displacements, 230 nm for the absolute in-plane displacement and 400 nm for the absolute out-of-plane displacement. For both campaigns, the test results have been compared to the predictions obtained by finite element analyses and the correlation of these results was good.
Ando, R.
2014-12-01
The boundary integral equation method formulated in the real space and time domain (BIEM-ST) has been used as a powerful tool to analyze the earthquake rupture dynamics on non-planar faults. Generally, BIEM is more accurate than volumetric methods such as the finite difference method and the finite difference method. With the recent development of the high performance computing environment, the earthquake rupture simulation studies have been conducted considering three dimensional realistic fault geometry models. However, the utility of BIEM-ST has been limited due to its heavy computational demanding increased depending on square of time steps (N2), which was needed to evaluate the historic integration. While BIEM can be efficient with the spectral domain formulation, the applications of such a method are limited to planar fault cases. In this study, we propose a new method to reduce the calculation time of BIEM-ST to linear of time step (N) without degrading the accuracy in the 3 dimensional modeling space. We extends the method proposed earlier for the case of the 2 dimensional framework, applying the asymptotic expressions of the elasto-dynamic Green's functions. This method uses the physical nature of the stress Green's function as dividing the causality cone according to the distances from the wave-fronts. The scalability of this method is shown on the parallel computing environment of the distributed memory. We demonstrate the applicability to analyses of subduction earthquake cases, suffering long time from the numerical limitations of previously available BIEMs. We analyze the dynamic rupture processes on dipping reverse faults embed in a three dimensional elastic half space.
DYNA3D, 3-D Finite Elements for Dynamic Response of Inelastic Solids
1 - Description of program or function: DYNA3D is an explicit, three- dimensional, finite element program for analyzing the large deformation dynamic response of inelastic solids and structures. DYNA3D contain 30 material models and 10 equations of state (EOS) to cover a wide range of material behavior. The material models implemented are: elastic, orthotropic elastic, kinematic/isotropic plasticity, thermo-elastoplastic, soil and crushable foam, linear viscoelastic, Blatz-Ko rubber, high explosive burn, hydrodynamic without deviatoric stresses, elastoplastic hydrodynamic, temperature dependent elastoplastic, isotropic elastoplastic, isotropic elastoplastic with failure, soil and crushable foam with failure, Johnson/Cook plasticity model, pseudo TENSOR geological model, elastoplastic with fracture, power law isotropic plasticity, strain rate dependent plasticity, rigid, thermal orthotropic, composite damage model, thermal orthotropic with 12 curves, piecewise linear isotropic plasticity, and inviscid two invariant geologic cap, orthotropic crushable model, Moonsy-Rivlin rubber, resultant plasticity, closed form update shell plasticity, and Frazer-Nash rubber model. The IBM 3090 version does not contain the last two models mentioned. The hydrodynamic material models determine only the deviatoric stresses. Pressure is determined by one of ten equations of state including linear polynomial, JWL high explosive, Sack 'Tuesday' high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, tabulated, and TENSOR pore collapse. DYNA3D generates three binary output databases. One contains information for complete states at infrequent intervals; 50 to 100 states is typical. The second contains information for a subset of nodes and elements at frequent intervals; 1,000 to 10,000 states is typical. The last contains interfaces data for contact surfaces. 2 - Method of solution: A contact
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
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
Modelling elasticity in solids using active cubes - application to simulated operations
Bro-Nielsen, Morten
The paper describes an approach to elastic modelling of human tissue based on the use of 3D solid active models-active cubes (M. Bro-Nielsen, 1994)-and a shape description based on the metric tensor in a solid. Active cubes are used because they provide a natural parameterization of the surface and....... The application of this approach to modelling the elastic deformation of human tissue in response to movement of bones is demonstrated...
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.
This book explains modeling of solid works 3D and application of 3D CAD/CAM. The contents of this book are outline of modeling such as CAD and 2D and 3D, solid works composition, method of sketch, writing measurement fixing, selecting projection, choosing condition of restriction, practice of sketch, making parts, reforming parts, modeling 3D, revising 3D modeling, using pattern function, modeling necessaries, assembling, floor plan, 3D modeling method, practice floor plans for industrial engineer data aided manufacturing, processing of CAD/CAM interface.
A strain tensor that couples to the Madelung stress tensor
Delphenich, D H
2013-01-01
Ordinarily, the stress tensor that one derives for a Madelung fluid is not regarded as being coupled to a strain tensor, which is consistent with the fluid hypothesis. However, based upon earlier work regarding the geometric nature of the quantum potential, one can, in fact, define a strain tensor, which is not, however, due to a deformation of a spatial region, but to a deformation of a frame field on that region. When one expresses the Madelung stress tensor as a function of the strain tensor and its derivatives, one then defines a constitutive law for the Madelung medium that might lead to a more detailed picture of its elementary structure. It is pointed out that the resulting constitutive law is strongly analogous to laws that were presented by Kelvin and Tait for the bending and torsion of elastic wires and plates, as well as the Einstein equations for gravitation if one takes the viewpoint of metric elasticity.
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.
3d-3d correspondence revisited
Chung, Hee-Joong; Dimofte, Tudor; Gukov, Sergei; Sułkowski, Piotr
2016-04-01
In fivebrane compactifications on 3-manifolds, we point out the importance of all flat connections in the proper definition of the effective 3d {N}=2 theory. The Lagrangians of some theories with the desired properties can be constructed with the help of homological knot invariants that categorify colored Jones polynomials. Higgsing the full 3d theories constructed this way recovers theories found previously by Dimofte-Gaiotto-Gukov. We also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.
Brdnik, Lovro
2015-01-01
Diplomsko delo analizira trenutno stanje 3D tiskalnikov na trgu. Prikazan je razvoj in principi delovanja 3D tiskalnikov. Predstavljeni so tipi 3D tiskalnikov, njihove prednosti in slabosti. Podrobneje je predstavljena zgradba in delovanje koračnih motorjev. Opravljene so meritve koračnih motorjev. Opisana je programska oprema za rokovanje s 3D tiskalniki in komponente, ki jih potrebujemo za izdelavo. Diploma se oklepa vprašanja, ali je izdelava 3D tiskalnika bolj ekonomična kot pa naložba v ...
Meulien Ohlmann, Odile
2013-02-01
Today the industry offers a chain of 3D products. Learning to "read" and to "create in 3D" becomes an issue of education of primary importance. 25 years professional experience in France, the United States and Germany, Odile Meulien set up a personal method of initiation to 3D creation that entails the spatial/temporal experience of the holographic visual. She will present some different tools and techniques used for this learning, their advantages and disadvantages, programs and issues of educational policies, constraints and expectations related to the development of new techniques for 3D imaging. Although the creation of display holograms is very much reduced compared to the creation of the 90ies, the holographic concept is spreading in all scientific, social, and artistic activities of our present time. She will also raise many questions: What means 3D? Is it communication? Is it perception? How the seeing and none seeing is interferes? What else has to be taken in consideration to communicate in 3D? How to handle the non visible relations of moving objects with subjects? Does this transform our model of exchange with others? What kind of interaction this has with our everyday life? Then come more practical questions: How to learn creating 3D visualization, to learn 3D grammar, 3D language, 3D thinking? What for? At what level? In which matter? for whom?
DYNA3D2000*, Explicit 3-D Hydrodynamic FEM Program
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
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....
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.
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'
Hundebøl, Jesper
wave of new building information modelling tools demands further investigation, not least because of industry representatives' somewhat coarse parlance: Now the word is spreading -3D digital modelling is nothing less than a revolution, a shift of paradigm, a new alphabet... Research qeustions. Based...... on empirical probes (interviews, observations, written inscriptions) within the Danish construction industry this paper explores the organizational and managerial dynamics of 3D Digital Modelling. The paper intends to - Illustrate how the network of (non-)human actors engaged in the promotion (and arrest) of 3......D Modelling (in Denmark) stabilizes - Examine how 3D Modelling manifests itself in the early design phases of a construction project with a view to discuss the effects hereof for i.a. the management of the building process. Structure. The paper introduces a few, basic methodological concepts...
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.
3D, 9-C anisotropic seismic modeling and inversion
Rusmanugroho, Herurisa
The most complete representation of an elastic medium consists of an elastic tensor with 21 independent moduli. All 21 can be estimated from compressional and shear wave polarization and slowness vectors corresponding to wide apertures of polar and azimuth angles. In isotropic media, when seismic source and receiver components have the same orientation (such as XX and YY), the reflection amplitude contours align approximately perpendicular to the particle motions. The mixed components (such as XY and YX) have amplitude patterns that are in symmetrical pairs of either the same, or of opposite, polarity on either side of the diagonal of the 9-C response matrix. In anisotropic media, amplitude variations with azimuth show the same basic patterns and symmetries as for isotropic, but with a superimposed tendency for alignment parallel to the strike of the vertical cracks. Solutions for elastic tensor elements from synthetic slowness and polarization data calculated directly from the Christoffel equation are more sensitive to the polar angle aperture than to the azimuth aperture. Nine-component synthetic elastic vertical seismic profile data for a model with triclinic symmetry calculated by finite-differencing allows estimation of the elastic 21 tensor elements in the vicinity of a three-component borehole receiver. Wide polar angle and azimuth apertures are needed for accurately estimating the elastic tensor elements. The tensor elements become less independent as the data apertures decrease. Results obtained by extracting slowness and polarization data from the corresponding synthetic seismograms show similar results. The inversion algorithm has produced good results from field vertical seismic profile data set from the Weyburn Field in Southern Saskatchewan in Canada. Synthetic nine-component seismograms calculated from the extracted tensor are able to explain most of the significant features in the field data. The inverted stiffness elastic tensor shows orthorhombic
Alaoui-Ismaili, N.; Guy, P.; Chassignole, B.
2014-02-01
The aim of this work is to measure the complex elastic tensor and Euler angles in very complex anisotropic media like austenitic steel welds, by inverse problem resolution from experimental data. The obtained experimental characteristics of the anisotropic material will be injected in a FE code developed by EDF enabling the simulation of an actual ultrasonic NDE of welds. The present work aims to provide reliable input data to the 3D future development of the code. In particular, this complex elastic tensor will allow to predict by modeling beam skewing ant attenuation in an austenitic weld. The investigation of such anisotropic media is very complex because of the directional dependency of the elastic stiffness tensor. Then we will discuss the use of a hybrid genetic algorithm to overcome this difficulty. The identification method is based on waveforms spectra reconstruction associated to a physical model describing wave propagation in plates, during underwater measurements. The entire procedure is qualified and validated using simulated data. Moreover, a comparison of the estimated elastic coefficients with literature values and ultrasonic measurements obtained in transmission is also given, at the end of the paper.
Alaoui-Ismaili, N. [INSA-Lyon, MATEIS, UMR5510 Villeurbanne, F-69621 (France); Guy, P. [INSA-Lyon, LVA, EA677 Villeurbanne, F-69621 (France); Chassignole, B. [EDF R and D, Moret sur Loing, F77818 (France)
2014-02-18
The aim of this work is to measure the complex elastic tensor and Euler angles in very complex anisotropic media like austenitic steel welds, by inverse problem resolution from experimental data. The obtained experimental characteristics of the anisotropic material will be injected in a FE code developed by EDF enabling the simulation of an actual ultrasonic NDE of welds. The present work aims to provide reliable input data to the 3D future development of the code. In particular, this complex elastic tensor will allow to predict by modeling beam skewing ant attenuation in an austenitic weld. The investigation of such anisotropic media is very complex because of the directional dependency of the elastic stiffness tensor. Then we will discuss the use of a hybrid genetic algorithm to overcome this difficulty. The identification method is based on waveforms spectra reconstruction associated to a physical model describing wave propagation in plates, during underwater measurements. The entire procedure is qualified and validated using simulated data. Moreover, a comparison of the estimated elastic coefficients with literature values and ultrasonic measurements obtained in transmission is also given, at the end of the paper.
3D Spectroscopic Instrumentation
Bershady, Matthew A
2009-01-01
In this Chapter we review the challenges of, and opportunities for, 3D spectroscopy, and how these have lead to new and different approaches to sampling astronomical information. We describe and categorize existing instruments on 4m and 10m telescopes. Our primary focus is on grating-dispersed spectrographs. We discuss how to optimize dispersive elements, such as VPH gratings, to achieve adequate spectral resolution, high throughput, and efficient data packing to maximize spatial sampling for 3D spectroscopy. We review and compare the various coupling methods that make these spectrographs ``3D,'' including fibers, lenslets, slicers, and filtered multi-slits. We also describe Fabry-Perot and spatial-heterodyne interferometers, pointing out their advantages as field-widened systems relative to conventional, grating-dispersed spectrographs. We explore the parameter space all these instruments sample, highlighting regimes open for exploitation. Present instruments provide a foil for future development. We give an...
Halskov, Kim; Johansen, Stine Liv; Bach Mikkelsen, Michelle
2014-01-01
Three-dimensional projection installations are particular kinds of augmented spaces in which a digital 3-D model is projected onto a physical three-dimensional object, thereby fusing the digital content and the physical object. Based on interaction design research and media studies, this article...... contributes to the understanding of the distinctive characteristics of such a new medium, and identifies three strategies for designing 3-D projection installations: establishing space; interplay between the digital and the physical; and transformation of materiality. The principal empirical case, From...... Fingerplan to Loop City, is a 3-D projection installation presenting the history and future of city planning for the Copenhagen area in Denmark. The installation was presented as part of the 12th Architecture Biennale in Venice in 2010....
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
Iliesiu, Luca; Kos, Filip; Poland, David; Pufu, Silviu S.; Simmons-Duffin, David; Yacoby, Ran
2016-03-01
We study the conformal bootstrap for a 4-point function of fermions 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 T . We observe features in our bounds that coincide with scaling dimensions in the GrossNeveu models at large N . We also speculate that other features could coincide with a fermionic CFT containing no relevant scalar operators.
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....
Kotek, L.
2015-01-01
This paper is about 3D scan of plaster dental casts. The main aim of the work is a hardware and software proposition of 3D scan system for scanning of dental casts. There were used camera, projector and rotate table for this scanning system. Surface triangulation was used, taking benefits of projections of structured light on object, which is being scanned. The rotate table is controlled by PC. The camera, projector and rotate table are synchronized by PC. Controlling of stepper motor is prov...
Ms. Swapnali R. Ghadge
2013-01-01
In today’s ever-shifting media landscape, it can be a complex task to find effective ways to reach your desired audience. As traditional media such as television continue to lose audience share, one venue in particular stands out for its ability to attract highly motivated audiences and for its tremendous growth potential the 3D Internet. The concept of '3D Internet' has recently come into the spotlight in the R&D arena, catching the attention of many people, and leading to a lot o...
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...
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...
M.M. Voormolen
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
Klusoň, Jindřich
2010-01-01
Computer animation has a growing importance and application in the world. With expansion of technologies increases quality of the final animation as well as number of 3D animation software. This thesis is currently mapped animation software for creating animation in film, television industry and video games which are advisable users requirements. Of them were selected according to criteria the best - Autodesk Maya 2011. This animation software is unique with tools for creating special effects...
Andringa, Roel; de Roo, Mees; Hohm, Olaf; Sezgin, Ergin; Townsend, Paul K
2009-01-01
We construct the N=1 three-dimensional supergravity theory with cosmological, Einstein-Hilbert, Lorentz Chern-Simons, and general curvature squared terms. We determine the general supersymmetric configuration, and find a family of supersymmetric adS vacua with the supersymmetric Minkowski vacuum as a limiting case. Linearizing about the Minkowski vacuum, we find three classes of unitary theories; one is the supersymmetric extension of the recently discovered `massive 3D gravity'. Another is a `new topologically massive supergravity' (with no Einstein-Hilbert term) that propagates a single (2,3/2) helicity supermultiplet.
Andringa, Roel; Bergshoeff, Eric A; De Roo, Mees; Hohm, Olaf [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Sezgin, Ergin [George and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Townsend, Paul K, E-mail: E.A.Bergshoeff@rug.n, E-mail: O.Hohm@rug.n, E-mail: sezgin@tamu.ed, E-mail: P.K.Townsend@damtp.cam.ac.u [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)
2010-01-21
We construct the N=1 three-dimensional supergravity theory with cosmological, Einstein-Hilbert, Lorentz Chern-Simons, and general curvature squared terms. We determine the general supersymmetric configuration, and find a family of supersymmetric adS vacua with the supersymmetric Minkowski vacuum as a limiting case. Linearizing about the Minkowski vacuum, we find three classes of unitary theories; one is the supersymmetric extension of the recently discovered 'massive 3D gravity'. Another is a 'new topologically massive supergravity' (with no Einstein-Hilbert term) that propagates a single (2,3/2) helicity supermultiplet.
Ms. Swapnali R. Ghadge
2013-08-01
Full Text Available In today’s ever-shifting media landscape, it can be a complex task to find effective ways to reach your desired audience. As traditional media such as television continue to lose audience share, one venue in particular stands out for its ability to attract highly motivated audiences and for its tremendous growth potential the 3D Internet. The concept of '3D Internet' has recently come into the spotlight in the R&D arena, catching the attention of many people, and leading to a lot of discussions. Basically, one can look into this matter from a few different perspectives: visualization and representation of information, and creation and transportation of information, among others. All of them still constitute research challenges, as no products or services are yet available or foreseen for the near future. Nevertheless, one can try to envisage the directions that can be taken towards achieving this goal. People who take part in virtual worlds stay online longer with a heightened level of interest. To take advantage of that interest, diverse businesses and organizations have claimed an early stake in this fast-growing market. They include technology leaders such as IBM, Microsoft, and Cisco, companies such as BMW, Toyota, Circuit City, Coca Cola, and Calvin Klein, and scores of universities, including Harvard, Stanford and Penn State.
The structures of linear chain Fe(II) spin-crossover compounds of α,β- and α,ω-bis (tetrazol-1-yl)alkane type ligands are described in relation to their magnetic properties. The first threefold interlocked 3-D catenane Fe(II) spin-transition system, [p-tris(1,4-bis(tetrazol-1-yl)butane-N1,N1') iron(II)] bis(perchlorate), will be discussed. An analysis is made among the structures and the cooperativity of the spin-crossover behavior of polynuclear Fe(II) spin-transition materials. Refs. 42 (author)
A spin-4 analog of 3D massive gravity
Bergshoeff, Eric A.; Kovacevic, Marija; Rosseel, Jan; Townsend, Paul K.; Yin, Yihao
2011-01-01
A sixth-order, but ghost-free, gauge-invariant action is found for a fourth-rank symmetric tensor potential in a three-dimensional (3D) Minkowski spacetime. It propagates two massive modes of spin 4 that are interchanged by parity and is thus a spin-4 analog of linearized 'new massive gravity'. Also
Holographic renormalization of 3D minimal massive gravity
Alishahiha, Mohsen; Qaemmaqami, Mohammad; Naseh, Ali; Shirzad, Ahmad
2016-01-01
We study holographic renormalization of 3D minimal massive gravity using the Chern-Simons-like formulation of the model. We explicitly present Gibbons- Hawking term as well as all counterterms needed to make the action finite in terms of dreibein and spin-connection. This can be used to find correlation functions of stress tensor of holographic dual field theory.
NIKE3D, Static and Dynamic Response of 3-D Solids
1 - Description of program or function: NIKE3D is a vectorized, fully implicit, three-dimensional, finite-element program for analyzing the finite-strain, static and dynamic response of inelastic solids, shells, and beams. Capabilities currently available include sliding interfaces, body force loads due to base acceleration, body force loads due to spinning (geometry dependent), concentrated nodal loads, pressure boundary conditions (geometry dependent), displacement boundary conditions, thermal stresses, plot-file generation, and problem restart. 2 - Method of solution: Spatial discretization is accomplished using eight-node solid elements that are integrated using a two-point Gauss quadrature rule, four-node shell elements that use a 2x2 Gauss integration in the surface and from 1 to 5 integration points through the thickness, and two-node thick beam elements using from 1 to 5 integration points in each local direction of the cross section at the center of the beam. Elastic, orthotropic elastic, elastic-plastic, thermo-elastic-plastic, soil and crushable foam, linear viscoelastic, thermo-orthotropic elastic, and thermo-elastic- creep material models are implemented. An incremental-interactive numerical algorithm, based on the Green-Naghdi and Jaumann stress rate formulations, is implemented in NIKE3D. Five iterative schemes are available including the BFGS quasi-Newton method, Broyden's quasi-Newton method, modified Newton-Raphson, full Newton, and full Newton with line search
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
Szkandera, Jan
2009-01-01
Tato bakalářská práce se zabývá návrhem a realizací systému, který umožní obraz scény zobrazovaný na ploše vnímat prostorově. Prostorové vnímání 2D obrazové informace je umožněno jednak stereopromítáním a jednak tím, že se obraz mění v závislosti na poloze pozorovatele. Tato práce se zabývá hlavně druhým z těchto problémů. This Bachelor's thesis goal is to design and realize system, which allows user to perceive 2D visual information as three-dimensional. 3D visual preception of 2D image i...
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
X3D: Extensible 3D Graphics Standard
Daly, Leonard; Brutzman, Don
2007-01-01
The article of record as published may be located at http://dx.doi.org/10.1109/MSP.2007.905889 Extensible 3D (X3D) is the open standard for Web-delivered three-dimensional (3D) graphics. It specifies a declarative geometry definition language, a run-time engine, and an application program interface (API) that provide an interactive, animated, real-time environment for 3D graphics. The X3D specification documents are freely available, the standard can be used without paying any royalties,...
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
Aboufadel, Edward F.
2014-01-01
The purpose of this short paper is to describe a project to manufacture a regular octohedron on a 3D printer. We assume that the reader is familiar with the basics of 3D printing. In the project, we use fundamental ideas to calculate the vertices and faces of an octohedron. Then, we utilize the OPENSCAD program to create a virtual 3D model and an STereoLithography (.stl) file that can be used by a 3D printer.
Higher derivative extensions of 3 d Chern–Simons models: conservation laws and stability
Kaparulin, D. S.; Karataeva, I. Yu.; Lyakhovich, S. L.
2015-01-01
We consider the class of higher derivative $3d$ vector field models with the field equation operator being a polynomial of the Chern-Simons operator. For $n$-th order theory of this type, we provide a general receipt for constructing $n$-parameter family of conserved second rank tensors. The family includes the canonical energy-momentum tensor, which is unbounded, while there are bounded conserved tensors that provide classical stability of the system for certain combinations of the parameter...
Rodrigues, Marcos; Robinson, Alan; Alboul, Lyuba; Brink, Willie
2006-01-01
3D face recognition is an open field. In this paper we present a method for 3D facial recognition based on Principal Components Analysis. The method uses a relatively large number of facial measurements and ratios and yields reliable recognition. We also highlight our approach to sensor development for fast 3D model acquisition and automatic facial feature extraction.
3-D contextual Bayesian classifiers
Larsen, Rasmus
distribution for the pixel values as well as a prior distribution for the configuration of class variables within the cross that is made of a pixel and its four nearest neighbours. We will extend these algorithms to 3-D, i.e. we will specify a simultaneous Gaussian distribution for a pixel and its 6 nearest 3......-D neighbours, and generalise the class variable configuration distributions within the 3-D cross given in 2-D algorithms. The new 3-D algorithms are tested on a synthetic 3-D multivariate dataset....
Taming Supersymmetric Defects in 3d-3d Correspondence
Gang, Dongmin; Romo, Mauricio; Yamazaki, Masahito
2015-01-01
We study knots in 3d Chern-Simons theory with complex gauge group $SL(N,\\mathbb{C})$, in the context of its relation with 3d $\\mathcal{N}=2$ theory (the so-called 3d-3d correspondence). The defect has either co-dimension 2 or co-dimension 4 inside the 6d $(2,0)$ theory, which is compactified on a 3-manifold $\\hat{M}$. We identify such defects in various corners of the 3d-3d correspondence, namely in 3d $SL(N,\\mathbb{C})$ Chern-Simons theory, in 3d $\\mathcal{N}=2$ theory, in 5d $\\mathcal{N}=2$ super Yang-Mills theory, and in the M-theory holographic dual. We can make quantitative checks of the 3d-3d correspondence by computing partition functions at each of these theories. This Letter is a companion to a longer paper, which contains more details and more results.
Burgos, Gaël.; Capdeville, Yann; Guillot, Laurent
2016-06-01
We investigate the effect of small-scale heterogeneities close to a seismic explosive source, at intermediate periods (20-50 s), with an emphasis on the resulting nonisotropic far-field radiation. First, using a direct numerical approach, we show that small-scale elastic heterogeneities located in the near-field of an explosive source, generate unexpected phases (i.e., long period S waves). We then demonstrate that the nonperiodic homogenization theory applied to 2-D and 3-D elastic models, with various pattern of small-scale heterogeneities near the source, leads to accurate waveforms at a reduced computational cost compared to direct modeling. Further, it gives an interpretation of how nearby small-scale features interact with the source at low frequencies, through an explicit correction to the seismic moment tensor. In 2-D simulations, we find a deviatoric contribution to the moment tensor, as high as 21% for near-source heterogeneities showing a 25% contrast of elastic values (relative to a homogeneous background medium). In 3-D this nonisotropic contribution reaches 27%. Second, we analyze intermediate-periods regional seismic waveforms associated with some underground nuclear explosions conducted at the Nevada National Security Site and invert for the full moment tensor, in order to quantify the relative contribution of the isotropic and deviatoric components of the tensor. The average value of the deviatoric part is about 35%. We conclude that the interactions between an explosive source and small-scale local heterogeneities of moderate amplitude may lead to a deviatoric contribution to the seismic moment, close to what is observed using regional data from nuclear test explosions.
3D Cell Culture in Alginate Hydrogels
Therese Andersen
2015-03-01
Full Text Available This review compiles information regarding the use of alginate, and in particular alginate hydrogels, in culturing cells in 3D. Knowledge of alginate chemical structure and functionality are shown to be important parameters in design of alginate-based matrices for cell culture. Gel elasticity as well as hydrogel stability can be impacted by the type of alginate used, its concentration, the choice of gelation technique (ionic or covalent, and divalent cation chosen as the gel inducing ion. The use of peptide-coupled alginate can control cell–matrix interactions. Gelation of alginate with concomitant immobilization of cells can take various forms. Droplets or beads have been utilized since the 1980s for immobilizing cells. Newer matrices such as macroporous scaffolds are now entering the 3D cell culture product market. Finally, delayed gelling, injectable, alginate systems show utility in the translation of in vitro cell culture to in vivo tissue engineering applications. Alginate has a history and a future in 3D cell culture. Historically, cells were encapsulated in alginate droplets cross-linked with calcium for the development of artificial organs. Now, several commercial products based on alginate are being used as 3D cell culture systems that also demonstrate the possibility of replacing or regenerating tissue.
Rubber Impact on 3D Textile Composites
Heimbs, Sebastian; Van Den Broucke, Björn; Duplessis Kergomard, Yann; Dau, Frederic; Malherbe, Benoit
2012-06-01
A low velocity impact study of aircraft tire rubber on 3D textile-reinforced composite plates was performed experimentally and numerically. In contrast to regular unidirectional composite laminates, no delaminations occur in such a 3D textile composite. Yarn decohesions, matrix cracks and yarn ruptures have been identified as the major damage mechanisms under impact load. An increase in the number of 3D warp yarns is proposed to improve the impact damage resistance. The characteristic of a rubber impact is the high amount of elastic energy stored in the impactor during impact, which was more than 90% of the initial kinetic energy. This large geometrical deformation of the rubber during impact leads to a less localised loading of the target structure and poses great challenges for the numerical modelling. A hyperelastic Mooney-Rivlin constitutive law was used in Abaqus/Explicit based on a step-by-step validation with static rubber compression tests and low velocity impact tests on aluminium plates. Simulation models of the textile weave were developed on the meso- and macro-scale. The final correlation between impact simulation results on 3D textile-reinforced composite plates and impact test data was promising, highlighting the potential of such numerical simulation tools.
Bjoerck, A.; Thor, S.E. [Aeronautical Research Inst. of Sweden, Bromma (Sweden)
1996-12-01
The JOULE II project `Dynamic stall and 3D effects` started in January 1994 and was completed in September 1995. The objective of the project has been to increase the understanding of the three-dimensional and unsteady aerodynamics of stall controlled HAWT`s. The objectives have also been to develop `engineering models` suitable for inclusion into aero-elastic codes. The project included the participation of 13 parties within Europe. This paper describes an overview of the work carried out within the project and key results. 3 refs, 4 figs
Harvesting vibrations via 3D phononic isolators
Psarobas, Ioannis E.; Yannopapas, Vassilios; Matikas, Theodore E.
2016-05-01
We report on the existence of unidirectional phononic band gaps that may span over extended regions of the Brillouin zone and can find application in trapping elastic (acoustic) waves in properly designed multilayered 3D structures. Phononic isolators operate as a result of asymmetrical wave transmission through a slab of a crystallographic phononic structure with broken mirror symmetry. Due to the use of lossless materials in the crystal, the absorption rate is dramatically enhanced when the proposed isolator is placed next to a vibrational harvesting cell. xml:lang="fr"
Asymptotic expansion of the multi-orientable random tensor model
Fusy, Eric
2014-01-01
Three-dimensional random tensor models are a natural generalization of the celebrated matrix models. The associated tensor graphs, or 3D maps, can be classified with respect to a particular integer or half-integer, the degree of the respective graph. In this paper we analyze the general term of the asymptotic expansion in N, the size of the tensor, of a particular random tensor model, the multi-orientable tensor model. We perform their enumeration and we establish which are the dominant configurations of a given degree.
Three-dimensional conjugate gradients inversion of magnetotelluric impedance tensor
Complete text of publication follows. We have developed a three-dimensional conjugate gradients inversion algorithm of magnetotelluric (MT) impedance tensor. This inversion algorithm can be used to invert 3D MT area data and 2D MT profile data. The importance of including the on-diagonal impedance tensor terms, Zxx and Zyy, in 3D inversion is considered in the synthetic example. The results from the 3D inversion of synthetic 3D area data indicate that the results using all impedance tensor elements, Zxx, Zxy, Zyx and Zyy, in the inversion are better than those without using on-diagonal elements. Therefore, 3D inversion should include all tensor elements if possible. The results from the 3D inversion of synthetic 2D profile data show that reasonable images for structures beneath and near a single MT profile can be obtained if all tensor elements are used in the inversion of the profile data. Currently, most of MT data are still collected on 2D profiles. This inversion algorithm of impedance tensor can promote the practical application of 3D MT inversion. We also use this inversion algorithm to invert the real data in the kayabe area in Japan. From the trial inversion with the synthetic and real data, the validity and practicability of this inversion algorithm is verified.
On microcontinuum field theories: the Eshelby stress tensor and incompatibility conditions
Lazar, Markus; Maugin, Gerard A.
2015-01-01
We investigate linear theories of incompatible micromorphic elasticity, incompatible microstretch elasticity, incompatible micropolar elasticity and the incompatible dilatation theory of elasticity (elasticity with voids). The incompatibility conditions and Bianchi identities are derived and discussed. The Eshelby stress tensor (static energy momentum) is calculated for such inhomogeneous media with microstructure. Its divergence gives the driving forces for dislocations, disclinations, point...
Tensor Target Polarization at TRIUMF
Smith, G
2014-10-27
The first measurements of tensor observables in $\\pi \\vec{d}$ scattering experiments were performed in the mid-80's at TRIUMF, and later at SIN/PSI. The full suite of tensor observables accessible in $\\pi \\vec{d}$ elastic scattering were measured: $T_{20}$, $T_{21}$, and $T_{22}$. The vector analyzing power $iT_{11}$ was also measured. These results led to a better understanding of the three-body theory used to describe this reaction. %Some measurements were also made in the absorption and breakup channels. A direct measurement of the target tensor polarization was also made independent of the usual NMR techniques by exploiting the (nearly) model-independent result for the tensor analyzing power at 90$^\\circ _{cm}$ in the $\\pi \\vec{d} \\rightarrow 2p$ reaction. This method was also used to check efforts to enhance the tensor polarization by RF burning of the NMR spectrum. A brief description of the methods developed to measure and analyze these experiments is provided.
3D Printing Functional Nanocomposites
Leong, Yew Juan
2016-01-01
3D printing presents the ability of rapid prototyping and rapid manufacturing. Techniques such as stereolithography (SLA) and fused deposition molding (FDM) have been developed and utilized since the inception of 3D printing. In such techniques, polymers represent the most commonly used material for 3D printing due to material properties such as thermo plasticity as well as its ability to be polymerized from monomers. Polymer nanocomposites are polymers with nanomaterials composited into the ...
3D Elevation Program—Virtual USA in 3D
Lukas, Vicki; Stoker, J.M.
2016-01-01
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, 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
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
Larsen, Rasmus
1997-01-01
. This includes the specification of a Gaussian distribution for the pixel values as well as a prior distribution for the configuration of class variables within the cross that is m ade of a pixel and its four nearest neighbours. We will extend this algorithm to 3-D, i.e. we will specify a simultaneous Gaussian...... distr ibution for a pixel and its 6 nearest 3-D neighbours, and generalise the class variable configuration distribution within the 3-D cross. The algorithm is tested on a synthetic 3-D multivariate dataset....
3D Bayesian contextual classifiers
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....
Interactive 3D multimedia content
Cellary, Wojciech
2012-01-01
The book describes recent research results in the areas of modelling, creation, management and presentation of interactive 3D multimedia content. The book describes the current state of the art in the field and identifies the most important research and design issues. Consecutive chapters address these issues. These are: database modelling of 3D content, security in 3D environments, describing interactivity of content, searching content, visualization of search results, modelling mixed reality content, and efficient creation of interactive 3D content. Each chapter is illustrated with example a
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
The 3D model: explaining densification and deformation mechanisms by using 3D parameter plots.
Picker, Katharina M
2004-04-01
The aim of the study was to analyze very differently deforming materials using 3D parameter plots and consequently to gain deeper insights into the densification and deformation process described with the 3D model in order to define an ideal tableting excipient. The excipients used were dicalcium phosphate dihydrate (DCPD), sodium chloride (NaCl), microcrystalline cellulose (MCC), xylitol, mannitol, alpha-lactose monohydrate, maltose, hydroxypropyl methylcellulose (HPMC), sodium carboxymethylcellulose (NaCMC), cellulose acetate (CAC), maize starch, potato starch, pregelatinized starch, and maltodextrine. All of the materials were tableted to graded maximum relative densities (rhorel, max) using an eccentric tableting machine. The data which resulted, namely force, displacement, and time, were analyzed by the application of 3D modeling. Different particle size fractions of DCPD, CAC, and MCC were analyzed in addition. Brittle deforming materials such as DCPD exhibited a completely different 3D parameter plot, with low time plasticity, d, and low pressure plasticity, e, and a strong decrease in omega values when densification increased, in contrast to the plastically deforming MCC, which had much higher d, e, and omega values. e and omega values changed only slightly when densification increased for MCC. NaCl showed less of a decrease in omega values than DCPD did, and the d and e values were between those of MCC and DCPD. The sugar alcohols, xylitol and mannitol, behaved in a similar fashion to sodium chloride. This is also valid for the crystalline sugars, alpha-lactose monohydrate, and maltose. However, the sugars are more brittle than the sugar alcohols. The cellulose derivatives, HPMC, NaCMC, and CAC, are as plastic as MCC, however, their elasticity depends on substitution indicated by lower (more elastic) or higher (less elastic) omega values. The native starches, maize starch and potato starch, are very elastic, and pregelatinized starch and maltodextrine are
The physical property tensors of one-dimensional quasicrystals
Li Cui-Lian; Liu You-Yan
2004-01-01
According to the group representation theory, we derive the character formulae of representation-matrices of the physical property tensors for the one-dimensional (1D) quasicrystals. Based on this, we have calculated the numbers of independent components of representation-matrices for thermal expansion coefficient tensors, piezoelectric coefficient tensors and elastic constant tensors under 31 point-groups for the 1D quasicrystals. Moreover, we have deduced the particular matrix forms of these tensors under the 31 point-groups. This is an important complement of quasicrystal physical property.
3-D Experimental Fracture Analysis at High Temperature
John H. Jackson; Albert S. Kobayashi
2001-09-14
T*e, which is an elastic-plastic fracture parameter based on incremental theory of plasticity, was determined numerically and experimentally. The T*e integral of a tunneling crack in 2024-T3 aluminum, three point bend specimen was obtained through a hybrid analysis of moire interferometry and 3-D elastic-plastic finite element analysis. The results were verified by the good agreement between the experimentally and numerically determined T*e on the specimen surface.
Goda, Ibrahim; Ganghoffer, Jean-François
2015-11-01
The purpose of this paper is to develop a homogeneous, orthotropic couple-stress continuum model as a substitute of the 3D periodic heterogeneous cellular solid model of vertebral trabecular bone. Vertebral trabecular bone is modeled as a porous material with an idealized periodic structure made of 3D open cubic cells, which is effectively orthotropic. The chosen architecture is based on studies of samples taken from the central part of vertebral bodies. The effective properties are obtained based on the response of the representative volume element under prescribed boundary conditions. Mixed boundary conditions comprising both traction and displacement boundary conditions are applied on the structure boundaries. In this contribution, the effective mechanical constants of the effective couple-stress continuum are deduced by an equivalent strain energy method. The characteristic lengths for bending and torsion are identified from the resulting homogenized orthotropic moduli. We conduct this study computationally using a finite element approach. Vertebral trabecular bone is modeled either as a cellular solid or as a two-phase material consisting of bone tissue (stiff phase) forming a trabecular network, and a surrounding soft tissue referring to the bone marrow present in the pores. Both the bone tissue forming the network and the pores are assumed to be homogeneous linear elastic, and isotropic media. The scale effects on the predicted couple stress moduli of these networks are investigated by varying the size of the bone specimens over which the boundary conditions are applied. The analysis using mixed boundary conditions gives results that are independent of unit cell size when computing the first couple stress tensor, while it is dependent on the cell size as to the second couple stress tensor moduli. This study provides overall guidance on how the size of the trabecular specimen influence couple stresses elastic moduli of cellular materials, with focus on bones
无
2003-01-01
The disadvantage remaining in 3D scanning system and its reasons are discussed. A new host-and-slave structure with high speed image acquisition and processing system is proposed to quicken the image processing and improve the performance of 3D scanning system.
ECT Team, Purdue
2015-01-01
Building Bytes, by Brian Peters, is a project that uses desktop 3D printers to print bricks for architecture. Instead of using an expensive custom-made printer, it uses a normal standard 3D printer which is available for everyone and makes it more accessible and also easier for fabrication.
MT3D was first developed by Chunmiao Zheng in 1990 at S.S. Papadopulos & Associates, Inc. with partial support from the U.S. Environmental Protection Agency (USEPA). Starting in 1990, MT3D was released as a pubic domain code from the USEPA. Commercial versions with enhanced capab...
Strictly nonnegative tensors and nonnegative tensor partition
HU ShengLong; HUANG ZhengHai; QI LiQun
2014-01-01
We introduce a new class of nonnegative tensors—strictly nonnegative tensors.A weakly irreducible nonnegative tensor is a strictly nonnegative tensor but not vice versa.We show that the spectral radius of a strictly nonnegative tensor is always positive.We give some necessary and su？cient conditions for the six wellconditional classes of nonnegative tensors,introduced in the literature,and a full relationship picture about strictly nonnegative tensors with these six classes of nonnegative tensors.We then establish global R-linear convergence of a power method for finding the spectral radius of a nonnegative tensor under the condition of weak irreducibility.We show that for a nonnegative tensor T,there always exists a partition of the index set such that every tensor induced by the partition is weakly irreducible;and the spectral radius of T can be obtained from those spectral radii of the induced tensors.In this way,we develop a convergent algorithm for finding the spectral radius of a general nonnegative tensor without any additional assumption.Some preliminary numerical results show the feasibility and effectiveness of the algorithm.
Wood, Jo; Kirschenbauer, Sabine; Döllner, Jürgen;
2005-01-01
The notion of three-dimensionality is applied to five stages of the visualization pipeline. While 3D visulization is most often associated with the visual mapping and representation of data, this chapter also identifies its role in the management and assembly of data, and in the media used...... to display 3D imagery. The extra cartographic degree of freedom offered by using 3D is explored and offered as a motivation for employing 3D in visualization. The use of VR and the construction of virtual environments exploit navigational and behavioral realism, but become most usefil when combined...... with abstracted representations embedded in a 3D space. The interactions between development of geovisualization, the technology used to implement it and the theory surrounding cartographic representation are explored. The dominance of computing technologies, driven particularly by the gaming industry...
Finding Apparent Horizons in Dynamic 3D Numerical Spacetimes
Anninos, P.; Camarda, K.; Libson, J.; Masso, J.; Seidel, E; Suen, W.
1996-01-01
We have developed a general method for finding apparent horizons in 3D numerical relativity. Instead of solving for the partial differential equation describing the location of the apparent horizons, we expand the closed 2D surfaces in terms of symmetric trace--free tensors and solve for the expansion coefficients using a minimization procedure. Our method is applied to a number of different spacetimes, including numerically constructed spacetimes containing highly distorted axisymmetric blac...
Reeb Graph for Automatic 3D Cephalometry
Mestiri Makram
2014-03-01
Full Text Available The purpose of this study is to present a method of three-dimensional computed tomographic (3D-CT cephalometrics and its use to study cranio/maxilla-facial malformations. We propose a system for automatic localization of cephalometric landmarks using reeb graphs. Volumetric images of a patient were reconstructed into 3D mesh. The proposed method is carried out in three steps: we begin by applying 3d mesh skull simplification, this mesh was reconstructed from a head volumetric medical image, and then we extract a reeb graph. Reeb graph mesh extraction represents a skeleton composed in a number of nodes and arcs. We are interested in the node position; we noted that some reeb nodes could be considered as cephalometric landmarks under specific conditions. The third step is to identify these nodes automatically by using elastic mesh registration using “thin plate” transformation and clustering. Preliminary results show a landmarks recognition rate of more than 90%, very close to the manually provided landmarks positions made by a medical stuff.
PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITHOUT TURB3D)
Buning, P.
1994-01-01
PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into
PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITH TURB3D)
Buning, P.
1994-01-01
PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into
ADT-3D Tumor Detection Assistant in 3D
Jaime Lazcano Bello
2008-12-01
Full Text Available The present document describes ADT-3D (Three-Dimensional Tumor Detector Assistant, a prototype application developed to assist doctors diagnose, detect and locate tumors in the brain by using CT scan. The reader may find on this document an introduction to tumor detection; ADT-3D main goals; development details; description of the product; motivation for its development; result’s study; and areas of applicability.
Unassisted 3D camera calibration
Atanassov, Kalin; Ramachandra, Vikas; Nash, James; Goma, Sergio R.
2012-03-01
With the rapid growth of 3D technology, 3D image capture has become a critical part of the 3D feature set on mobile phones. 3D image quality is affected by the scene geometry as well as on-the-device processing. An automatic 3D system usually assumes known camera poses accomplished by factory calibration using a special chart. In real life settings, pose parameters estimated by factory calibration can be negatively impacted by movements of the lens barrel due to shaking, focusing, or camera drop. If any of these factors displaces the optical axes of either or both cameras, vertical disparity might exceed the maximum tolerable margin and the 3D user may experience eye strain or headaches. To make 3D capture more practical, one needs to consider unassisted (on arbitrary scenes) calibration. In this paper, we propose an algorithm that relies on detection and matching of keypoints between left and right images. Frames containing erroneous matches, along with frames with insufficiently rich keypoint constellations, are detected and discarded. Roll, pitch yaw , and scale differences between left and right frames are then estimated. The algorithm performance is evaluated in terms of the remaining vertical disparity as compared to the maximum tolerable vertical disparity.
Grutle, Øyvind Kallevik
2015-01-01
3D printers have in recent years become extremely popular. Even though 3D printing technology have existed since the late 1980's, it is now considered one of the most significant technological breakthroughs of the twenty-first century. Several different 3D printing processes have been invented during the years. But it is the fused deposition modeling (FDM) which was one of the first invented that is considered the most popular today. Even though the FDM process is the most popular, it still s...
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
Lin, Zeyu
2014-01-01
3D printing technology is introduced and defined in this Thesis. Some methods of 3D printing are illustrated and their principles are explained with pictures. Most of the essential parts are presented with pictures and their effects are explained within the whole system. Problems on Up! Plus 3D printer are solved and a DIY product is made with this machine. The processes of making product are recorded and the items which need to be noticed during the process are the highlight in this th...
Tuotekehitysprojekti: 3D-tulostin
Pihlajamäki, Janne
2011-01-01
Opinnäytetyössä tutustuttiin 3D-tulostamisen teknologiaan. Työssä käytiin läpi 3D-tulostimesta tehty tuotekehitysprojekti. Sen lisäksi esiteltiin yleisellä tasolla tuotekehitysprosessi ja syntyneiden tulosten mahdollisia suojausmenetelmiä. Tavoitteena tässä työssä oli kehittää markkinoilta jo löytyvää kotitulostin-tasoista 3D-laiteteknologiaa lähemmäksi ammattilaistason ratkaisua. Tavoitteeseen pyrittiin keskittymällä parantamaan laitteella saavutettavaa tulostustarkkuutta ja -nopeutt...
无
2002-01-01
This paper presents a principle and a method of col or 3D laser scanning measurement. Based on the fundamental monochrome 3D measureme nt study, color information capture, color texture mapping, coordinate computati on and other techniques are performed to achieve color 3D measurement. The syste m is designed and composed of a line laser light emitter, one color CCD camera, a motor-driven rotary filter, a circuit card and a computer. Two steps in captu ring object's images in the measurement process: Firs...
3-D neutron transport benchmarks
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 Keff, 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
Puntar, Matej
2012-01-01
The purpose of this thesis is the presentation of already established and new technologies of displaying 3D content in a web browser. The thesis begins with a short presentation of the history of 3D content available on the internet and its development together with advantages and disadvantages of individual technologies. The latter two are described in detail as well is their use and the differences among them. Special emphasis has been given to WebGL, the newest technology of 3D conte...
Gravitational Superenergy Tensor
Mashhoon, Bahram; McClune, James C.; Quevedo, Hernando
1996-01-01
We provide a physical basis for the local gravitational superenergy tensor. Furthermore, our gravitoelectromagnetic deduction of the Bel-Debever-Robinson superenergy tensor permits the identification of the gravitational stress-energy tensor. This {\\it local} gravitational analog of the Maxwell stress-energy tensor is illustrated for a plane gravitational wave.
Yang, Xu; Zhang, Yong; Yang, Chenghua; Xu, Lu; Wang, Qiang; Zhao, Yuan
2016-06-01
Conventional three dimensional (3D) ghost imaging measures range of target based on pulse fight time measurement method. Due to the limit of data acquisition system sampling rate, range resolution of the conventional 3D ghost imaging is usually low. In order to take off the effect of sampling rate to range resolution of 3D ghost imaging, a heterodyne 3D ghost imaging (HGI) system is presented in this study. The source of HGI is a continuous wave laser instead of pulse laser. Temporal correlation and spatial correlation of light are both utilized to obtain the range image of target. Through theory analysis and numerical simulations, it is demonstrated that HGI can obtain high range resolution image with low sampling rate.
Conducting polymer 3D microelectrodes
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...
Main: TATCCAYMOTIFOSRAMY3D [PLACE
Full Text Available TATCCAYMOTIFOSRAMY3D S000256 01-August-2006 (last modified) kehi TATCCAY motif found in rice (O. ... otif and G motif (see S000130) are responsible for sugar ... repression (Toyofuku et al. 1998); GATA; amylase; ...
The 3S1-3D1 mixing parameter ε1 and the 3PJ phase shifts in the N-N system at low energy are investigated in the three nucleon system. The sensitivity of polarization transfer coefficients in p-d elastic scattering is determined by rigorous Faddeev calculations using Paris and Bonn potentials. The experimental results of Kysup(y') favours the tensor force component of the Bonn A potential. (orig.)
Hess, Siegfried
2015-01-01
This book presents the science of tensors in a didactic way. The various types and ranks of tensors and the physical basis is presented. Cartesian Tensors are needed for the description of directional phenomena in many branches of physics and for the characterization the anisotropy of material properties. The first sections of the book provide an introduction to the vector and tensor algebra and analysis, with applications to physics, at undergraduate level. Second rank tensors, in particular their symmetries, are discussed in detail. Differentiation and integration of fields, including generalizations of the Stokes law and the Gauss theorem, are treated. The physics relevant for the applications in mechanics, quantum mechanics, electrodynamics and hydrodynamics is presented. The second part of the book is devoted to tensors of any rank, at graduate level. Special topics are irreducible, i.e. symmetric traceless tensors, isotropic tensors, multipole potential tensors, spin tensors, integration and spin-...
Lading, Brian; Larsen, Rasmus; Åström, Kalle
2006-01-01
We build a 3d face shape model, including inter- and intra-shape variations, derive the analytical jacobian of its resulting 2d rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations.}......We build a 3d face shape model, including inter- and intra-shape variations, derive the analytical jacobian of its resulting 2d rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations.}...
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...
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.
Design of manufacturable 3D extremal elastic microstructure
Andreassen, Erik; Lazarov, Boyan Stefanov; Sigmund, Ole
2014-01-01
, and the deviations are due to the imposed manufacturing constraints. The designs are generated using topology optimization. Due to high resolution and the imposed robustness requirement they are manufacturable without any need for post-processing. This has been validated by the manufacturing of an...
3D viscous-spring artificial boundary in time domain
Liu Jingbo; Du Yixin; Du Xiuli; Wang Zhenyu; Wu Jun
2006-01-01
After a brief review of studies on artificial boundaries in dynamic soil-structure interaction, a three-dimensional viscous-spring artificial boundary (VSAB) in the time domain is developed in this paper. First, the 3D VSAB equations in the normal and tangential directions are derived based on the elastic wave motion theory. Secondly, a numerical simulation technique of wave motion equations along with the VSAB condition in the time domain is studied. Finally, numerical examples of some classical elastic wave motion problems are presented and the results are compared with the associated theoretical solutions, demonstrating that high precision and adequate stability can be achieved by using the proposed 3D VSAB. The proposed 3D VSAB can be conveniently incorporated in the general finite element program, which is commonly used to study dynamic soil-structure interaction problems.
Brox, Thomas; Weickert, Joachim; Burgeth, Bernhard; Mrázek, Pavel
2004-01-01
In this article we introduce nonlinear versions of the popular structure tensor, also known as second moment matrix. These nonlinear structure tensors replace the Gaussian smoothing of the classical structure tensor by discontinuity-preserving nonlinear diffusions. While nonlinear diffusion is a well-established tool for scalar and vector-valued data, it has not often been used for tensor images so far. Two types of nonlinear diffusion processes for tensor data are studied: an isotropic one w...
Pomeron as a Reggeized Tensor Glueball
MA Wei-Xing; A.W.Thomas; SHEN Peng-Nian; ZHOU Li-Juan
2001-01-01
We study gluonic content of the pomeron and propose that the pomeron could be a reggeized tensor glueball ζ(2230) with quantum numbers IG JPc = 0+2++.This conjecture is examined in high energy proton-proton elastic scattering,and the calculations lend a favorable support to our physical idea.``
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
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.
Remote 3D Medical Consultation
Welch, Greg; Sonnenwald, Diane H.; Fuchs, Henry; Cairns, Bruce; Mayer-Patel, Ketan; Yang, Ruigang; State, Andrei; Towles, Herman; Ilie, Adrian; Krishnan, Srinivas; Söderholm, Hanna M.
Two-dimensional (2D) video-based telemedical consultation has been explored widely in the past 15-20 years. Two issues that seem to arise in most relevant case studies are the difficulty associated with obtaining the desired 2D camera views, and poor depth perception. To address these problems we are exploring the use of a small array of cameras to synthesize a spatially continuous range of dynamic three-dimensional (3D) views of a remote environment and events. The 3D views can be sent across wired or wireless networks to remote viewers with fixed displays or mobile devices such as a personal digital assistant (PDA). The viewpoints could be specified manually or automatically via user head or PDA tracking, giving the remote viewer virtual head- or hand-slaved (PDA-based) remote cameras for mono or stereo viewing. We call this idea remote 3D medical consultation (3DMC). In this article we motivate and explain the vision for 3D medical consultation; we describe the relevant computer vision/graphics, display, and networking research; we present a proof-of-concept prototype system; and we present some early experimental results supporting the general hypothesis that 3D remote medical consultation could offer benefits over conventional 2D televideo.
Materialedreven 3d digital formgivning
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...
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...
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...
DYADIC METHOD FOR TENSOR FUNCTIONS
黄永念; 鲁昊
2002-01-01
In this paper, we discuss tensor functions by dyadic representation of tensor. Two different cases of scalar invariants and two different cases of tensor invariants are calculated. It is concluded that there are six independent scale invariants for a symmetrical tensor and an antisymmetrical tensor, and there are twelve invariants for two symmetrical tensors and an antisymmetrical tensor. And we present a new list of tensor invariants for the tensor-valued isotropic function.
Modification of 3D milling machine to 3D printer
Halamíček, Lukáš
2015-01-01
Tato práce se zabývá přestavbou gravírovací frézky na 3D tiskárnu. V první části se práce zabývá možnými technologiemi 3D tisku a možností jejich využití u přestavby. Dále jsou popsány a vybrány vhodné součásti pro přestavbu. V další části je realizováno řízení ohřevu podložky, trysky a řízení posuvu drátu pomocí softwaru TwinCat od společnosti Beckhoff na průmyslovém počítači. Výsledkem práce by měla být oživená 3D tiskárna. This thesis deals with rebuilding of engraving machine to 3D pri...
3D Imager and Method for 3D imaging
Kumar, P.; Staszewski, R.; Charbon, E.
2013-01-01
3D imager comprising at least one pixel, each pixel comprising a photodetectorfor detecting photon incidence and a time-to-digital converter system configured for referencing said photon incidence to a reference clock, and further comprising a reference clock generator provided for generating the re
TRAB-3D is a reactor dynamics code with three-dimensional neutronics coupled to core and circuit thermal-hydraulics. The code, entirely developed at VTT, can be used in transient and accident analyses of boiling (BWR) and pressurized water (PWR) reactors with rectangular fuel bundle geometry. The validation history of TRAB-3D includes calculation of international benchmark exercises, as well as comparisons with measured data from real plant transients. The most recent validation case is a load rejection test performed at the Olkiluoto 1 nuclear power plant in 1998 in connection with the power uprating project. The fact that there is local power measurement data available from this test makes it a suitable case for three-dimensional core model validation. The agreement between the results of the TRAB-3D calculation and the measurements is very good. (orig.)
Becker, T; Roth, M M; Becker, Thomas; Fabrika, Sergei; Roth, Martin M.
2003-01-01
The quantitative spectroscopy of stellar objects in complex environments is mainly limited by the ability of separating the object from the background. Standard slit spectroscopy, restricting the field of view to one dimension, is obviously not the proper technique in general. The emerging Integral Field (3D) technique with spatially resolved spectra of a two-dimensional field of view provides a great potential for applying advanced subtraction methods. In this paper an image reconstruction algorithm to separate point sources and a smooth background is applied to 3D data. Several performance tests demonstrate the photometric quality of the method. The algorithm is applied to real 3D observations of a sample Planetary Nebula in M31, whose spectrum is contaminated by the bright and complex galaxy background. The ability of separating sources is also studied in a crowded stellar field in M33.
Walder, Christian; Breidt, Martin; Bulthoff, Heinrich;
2009-01-01
We present a novel algorithm for the markerless tracking of deforming surfaces such as faces. We acquire a sequence of 3D scans along with color images at 40Hz. The data is then represented by implicit surface and color functions, using a novel partition-of-unity type method of efficiently...... combining local regressors using nearest neighbor searches. Both these functions act on the 4D space of 3D plus time, and use temporal information to handle the noise in individual scans. After interactive registration of a template mesh to the first frame, it is then automatically deformed to track...... the scanned surface, using the variation of both shape and color as features in a dynamic energy minimization problem. Our prototype system yields high-quality animated 3D models in correspondence, at a rate of approximately twenty seconds per timestep. Tracking results for faces and other objects...
Pihl, Michael Johannes
The main purpose of this PhD project is to develop an ultrasonic method for 3D vector flow imaging. The motivation is to advance the field of velocity estimation in ultrasound, which plays an important role in the clinic. The velocity of blood has components in all three spatial dimensions, yet...... conventional methods can estimate only the axial component. Several approaches for 3D vector velocity estimation have been suggested, but none of these methods have so far produced convincing in vivo results nor have they been adopted by commercial manufacturers. The basis for this project is the Transverse...... on the TO fields are suggested. They can be used to optimize the TO method. In the third part, a TO method for 3D vector velocity estimation is proposed. It employs a 2D phased array transducer and decouples the velocity estimation into three velocity components, which are estimated simultaneously based on 5...
3D-grafiikkamoottori mobiililaitteille
Vahlman, Lauri
2014-01-01
Tässä insinöörityössä käydään läpi mobiililaitteille suunnatun yksinkertaisen 3D-grafiikkamoottorin suunnittelu ja toteutus käyttäen OpenGL ES -rajapintaa. Työssä esitellään grafiikkamoottorin toteutuksessa käytettyjä tekniikoita sekä tutustutaan moottorin rakenteeseen ja toteutuksellisiin yksityiskohtiin. Työn alkupuolella tutustutaan myös modernin 3D-grafiikan yleisiin periaatteisiin ja toimintaan sekä käydään läpi 3D-grafiikkaan liittyviä suorituskykyongelmia. Työn loppupuolella esitel...
3D Computations and Experiments
Couch, R; Faux, D; Goto, D; Nikkel, D
2004-04-05
This project consists of two activities. Task A, Simulations and Measurements, combines all the material model development and associated numerical work with the materials-oriented experimental activities. The goal of this effort is to provide an improved understanding of dynamic material properties and to provide accurate numerical representations of those properties for use in analysis codes. Task B, ALE3D Development, involves general development activities in the ALE3D code with the focus of improving simulation capabilities for problems of mutual interest to DoD and DOE. Emphasis is on problems involving multi-phase flow, blast loading of structures and system safety/vulnerability studies.
Focused high energy ion beam micromachining is the newest of the micromachining techniques. There are about 50 scanning proton microprobe facilities worldwide, but so far only few of them showed activity in this promising field. High energy ion beam micromachining using a direct-write scanning MeV ion beam is capable of producing 3D microstructures and components with well defined lateral and depth geometry. The technique has high potential in the manufacture of 3D molds, stamps, and masks for X-ray lithography (LIGA), and also in the rapid prototyping of microcomponents either for research purposes or for components testing prior to batch production. (R.P.)
Manos, Harry
2016-01-01
Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the "TPT" theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity…
Lading, Brian; Larsen, Rasmus; Åström, Kalle
2006-01-01
We build a 3d face shape model, including inter- and intra-shape variations, derive the analytical jacobian of its resulting 2d rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations.}
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
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…
Pedersen, Pernille Klarskov; Strikwerda, Andrew; Wang, Tianwu;
2013-01-01
We present a characterization of THz beams generated in both a two-color air plasma and in a LiNbO3 crystal. Using a commercial THz camera, we record intensity images as a function of distance through the beam waist, from which we extract 2D beam profiles and visualize our measurements into 3D beam...
Krajnović, Davor
2016-01-01
Thanks to a technique that reveals galaxies in 3D, astronomers can now show that many galaxies have been wrongly classified. Davor Krajnovi\\'c argues that the classification scheme proposed 85 years ago by Edwin Hubble now needs to be revised.
3D electrohydrodynamic simulation of electrowetting displays
The fluid dynamic behavior within a pixel of an electrowetting display (EWD) is thoroughly investigated through a 3D simulation. By coupling the electrohydrodynamic (EHD) force deduced from the Maxwell stress tensor with the laminar phase field of the oil–water dual phase, the complete switch processes of an EWD, including the break-up and the electrowetting stages in the switch-on process (with voltage) and the oil spreading in the switch-off process (without voltage), are successfully simulated. By considering the factor of the change in the apparent contact angle at the contact line, the electro–optic performance obtained from the simulation is found to agree well with its corresponding experiment. The proposed model is used to parametrically predict the effect of interfacial (e.g. contact angle of grid) and geometric (e.g. oil thickness and pixel size) properties on the defects of an EWD, such as oil dewetting patterns, oil overflow, and oil non-recovery. With the help of the defect analysis, a highly stable EWD is both experimentally realized and numerically analyzed. (paper)
Introduction to Tensor Calculus
Sochi, Taha
2016-01-01
These are general notes on tensor calculus which can be used as a reference for an introductory course on tensor algebra and calculus. A basic knowledge of calculus and linear algebra with some commonly used mathematical terminology is presumed.
Priprava 3D modelov za 3D tisk
Pikovnik, Tomaž
2015-01-01
Po mnenju nekaterih strokovnjakov bo aditivna proizvodnja (ali 3D tiskanje) spremenila proizvodnjo industrijo, saj si bo vsak posameznik lahko natisnil svoj objekt po želji. V diplomski nalogi so predstavljene nekatere tehnologije aditivne proizvodnje. V nadaljevanju diplomske naloge je predstavljena izdelava makete hiše v merilu 1:100, vse od modeliranja do tiskanja. Poseben poudarek je posvečen predelavi modela, da je primeren za tiskanje, kjer je razvit pristop za hitrejše i...
Post processing of 3D models for 3D printing
Pikovnik, Tomaž
2015-01-01
According to the opinion of some experts the additive manufacturing or 3D printing will change manufacturing industry, because any individual could print their own model according to his or her wishes. In this graduation thesis some of the additive manufacturing technologies are presented. Furthermore in the production of house scale model in 1:100 is presented, starting from modeling to printing. Special attention is given to postprocessing of the building model elements us...
3D Cameras: 3D Computer Vision of Wide Scope
May, Stefan; Pervoelz, Kai; Surmann, Hartmut
2007-01-01
First of all, a short comparison of range sensors and their underlying principles was given. The chapter further focused on 3D cameras. The latest innovations have given a significant improvement for the measurement accuracy, wherefore this technology has attracted attention in the robotics community. This was also the motivation for the examination in this chapter. On this account, several applications were presented, which represents common problems in the domain of autonomous robotics. For...
Equations of motion for anisotropic nonlinear elastic continuum in gravitational field
Equations of motion for anisotropic nonlinear elastic continuum in the gravitational field are written in the form convenient for numerical calculations. The energy-stress tensor is expressed through scalar and tensor products of three vectors frozen in the continuum. Examples of expansion of the energy-stress tensor into scalar and tensor invariants corresponding to some crystal classes are given. 47 refs
Higher derivative extensions of 3 d Chern-Simons models: conservation laws and stability
Kaparulin, D. S.; Karataeva, I. Yu.; Lyakhovich, S. L.
2015-11-01
We consider the class of higher derivative 3 d vector field models with the field equation operator being a polynomial of the Chern-Simons operator. For the nth-order theory of this type, we provide a general recipe for constructing n-parameter family of conserved second rank tensors. The family includes the canonical energy-momentum tensor, which is unbounded, while there are bounded conserved tensors that provide classical stability of the system for certain combinations of the parameters in the Lagrangian. We also demonstrate the examples of consistent interactions which are compatible with the requirement of stability.
Higher derivative extensions of 3d Chern-Simons models: conservation laws and stability
Kaparulin, D.S.; Karataeva, I.Yu.; Lyakhovich, S.L. [Tomsk State University, Physics Faculty, Tomsk (Russian Federation)
2015-11-15
We consider the class of higher derivative 3d vector field models with the field equation operator being a polynomial of the Chern-Simons operator. For the nth-order theory of this type, we provide a general recipe for constructing n-parameter family of conserved second rank tensors. The family includes the canonical energy-momentum tensor, which is unbounded, while there are bounded conserved tensors that provide classical stability of the system for certain combinations of the parameters in the Lagrangian. We also demonstrate the examples of consistent interactions which are compatible with the requirement of stability. (orig.)
Higher derivative extensions of 3d Chern-Simons models: conservation laws and stability
We consider the class of higher derivative 3d vector field models with the field equation operator being a polynomial of the Chern-Simons operator. For the nth-order theory of this type, we provide a general recipe for constructing n-parameter family of conserved second rank tensors. The family includes the canonical energy-momentum tensor, which is unbounded, while there are bounded conserved tensors that provide classical stability of the system for certain combinations of the parameters in the Lagrangian. We also demonstrate the examples of consistent interactions which are compatible with the requirement of stability. (orig.)
Higher derivative extensions of $3d$ Chern-Simons models: conservation laws and stability
Kaparulin, D S; Lyakhovich, S L
2015-01-01
We consider the class of higher derivative $3d$ vector field models with the field equation operator being a polynomial of the Chern-Simons operator. For $n$-th order theory of this type, we provide a general receipt for constructing $n$-parameter family of conserved second rank tensors. The family includes the canonical energy-momentum tensor, which is unbounded, while there are bounded conserved tensors that provide classical stability of the system for certain combinations of the parameters in the Lagrangian. We also demonstrate the examples of consistent interactions which are compatible with the requirement of stability.
Bergshoeff, Eric; Merbis, Wout; Routh, Alasdair J.; Townsend, Paul K.
2015-01-01
Consistency of Einstein's gravitational field equation G(mu nu) proportional to T-mu nu imposes a "conservation condition" on the T-tensor that is satisfied by (i) matter stress tensors, as a consequence of the matter equations of motion and (ii) identically by certain other tensors, such as the met
Renormalizable Tensor Field Theories
Geloun, Joseph Ben
2016-01-01
Extending tensor models at the field theoretical level, tensor field theories are nonlocal quantum field theories with Feynman graphs identified with simplicial complexes. They become relevant for addressing quantum topology and geometry in any dimension and therefore form an interesting class of models for studying quantum gravity. We review the class of perturbatively renormalizable tensor field theories and some of their features.
Introduction to linear elasticity
Gould, Phillip L
2013-01-01
Introduction to Linear Elasticity, 3rd Edition, provides an applications-oriented grounding in the tensor-based theory of elasticity for students in mechanical, civil, aeronautical, and biomedical engineering, as well as materials and earth science. The book is distinct from the traditional text aimed at graduate students in solid mechanics by introducing the subject at a level appropriate for advanced undergraduate and beginning graduate students. The author's presentation allows students to apply the basic notions of stress analysis and move on to advanced work in continuum mechanics, plasticity, plate and shell theory, composite materials, viscoelasticity and finite method analysis. This book also: Emphasizes tensor-based approach while still distilling down to explicit notation Provides introduction to theory of plates, theory of shells, wave propagation, viscoelasticity and plasticity accessible to advanced undergraduate students Appropriate for courses following emerging trend of teaching solid mechan...
Large deformations of a new class of incompressible elastic bodies
Bustamante, R.; Orellana, O.; Meneses, R.; Rajagopal, K. R.
2016-06-01
The consequences of the constraint of incompressibility is studied for a new class of constitutive relation for elastic bodies, for which the left Cauchy-Green tensor is a function of the Cauchy stress tensor. The requirement of incompressibility is imposed directly in the constitutive relation, and it is not necessary to assume a priori that the stress tensor should be divided into two parts, a constraint stress and a constitutively specified part, as in the classical theory of nonlinear elasticity.
3-D Relativistic MHD Simulations
Nishikawa, K.-I.; Frank, J.; Koide, S.; Sakai, J.-I.; Christodoulou, D. M.; Sol, H.; Mutel, R. L.
1998-12-01
We present 3-D numerical simulations of moderately hot, supersonic jets propagating initially along or obliquely to the field lines of a denser magnetized background medium with Lorentz factors of W = 4.56 and evolving in a four-dimensional spacetime. The new results are understood as follows: Relativistic simulations have consistently shown that these jets are effectively heavy and so they do not suffer substantial momentum losses and are not decelerated as efficiently as their nonrelativistic counterparts. In addition, the ambient magnetic field, however strong, can be pushed aside with relative ease by the beam, provided that the degrees of freedom associated with all three spatial dimensions are followed self-consistently in the simulations. This effect is analogous to pushing Japanese ``noren'' or vertical Venetian blinds out of the way while the slats are allowed to bend in 3-D space rather than as a 2-D slab structure.
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.
Forensic 3D Scene Reconstruction
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
Forensic 3D Scene Reconstruction
LITTLE,CHARLES Q.; PETERS,RALPH R.; RIGDON,J. BRIAN; SMALL,DANIEL E.
1999-10-12
Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and contribute quantitative measurements such as accurate relative positioning of crime scene objects, would be an asset to law enforcement agents in collecting and recording significant forensic data. The purpose of this project is to develop a feasible prototype of a fast, accurate, 3D measurement and imaging system that would support law enforcement agents to quickly document and accurately record a crime scene.
[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.
Rivasseau, Vincent
2016-01-01
This note is a sequel to the previous series "Tensor Track I-III". Assuming some familiarity with the tensor track approach to quantum gravity, we provide a brief introduction to the developments of the last two years and to their corresponding bibliography. They center around understanding the interface between random matrices and random tensors through the intermediate field representation, finding new types of $1/N$ expansions by enhancing sub-leading tensor interactions, exploring the renormalization group flows in the tensor theory space, and developing the constructive aspects of the theory.
A spin-4 analog of 3D massive gravity
Bergshoeff, Eric A; Rosseel, Jan; Townsend, Paul K; Yin, Yihao
2011-01-01
A 6th-order, but ghost-free, gauge-invariant action is found for a 4th-rank symmetric tensor potential in a three-dimensional (3D) Minkowski spacetime. It propagates two massive modes of spin 4 that are interchanged by parity, and is thus a spin-4 analog of linearized "new massive gravity". Also found are ghost-free spin-4 analogs of linearized "topologically massive gravity" and "new topologically massive gravity", of 5th- and 8th-order respectively.
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.
INGRID, 3-D Mesh Generator for Program DYNA3D and NIKE3D and FACET and TOPAZ3D
1 - Description of program or function: INGRID is a general-purpose, three-dimensional mesh generator developed for use with finite element, nonlinear, structural dynamics codes. INGRID generates the large and complex input data files for DYNA3D (NESC 9909), NIKE3D (NESC 9725), FACET, and TOPAZ3D. One of the greatest advantages of INGRID is that virtually any shape can be described without resorting to wedge elements, tetrahedrons, triangular elements or highly distorted quadrilateral or hexahedral elements. Other capabilities available are in the areas of geometry and graphics. Exact surface equations and surface intersections considerably improve the ability to deal with accurate models, and a hidden line graphics algorithm is included which is efficient on the most complicated meshes. The most important new capability is associated with the boundary conditions, loads, and material properties required by nonlinear mechanics programs. Commands have been designed for each case to minimize user effort. This is particularly important since special processing is almost always required for each load or boundary condition. 2 - Method of solution: Geometries are described primarily using the index space notation of the INGEN program (NESC 975) with an additional type of notation, index progression. Index progressions provide a concise and simple method for describing complex structures; the concept was developed to facilitate defining multiple regions in index space. Rather than specifying the minimum and maximum indices for a region, one specifies the progression of indices along the I, J and K directions, respectively. The index progression method allows the analyst to describe most geometries including nodes and elements with roughly the same amount of input as a solids modeler
Järvinen, Manu
2009-01-01
Opinnäytetyössä tutkittiin tehokasta tapaa toteuttaa minuutin mittainen animaatio Scene.org Awards -tapahtuman avajaisseremoniaan. Kyseinen video toteutettiin osana opinnäytetyötä. Työhön osallistui tekijän lisäksi 3D-mallintaja sekä muusikko. Työkaluina käytettiin pääasiassa Autodesk 3ds Max-, sekä Adobe After Effects- ja Adobe Photoshop -ohjelmia. Opinnäytetyö koostuu animaatioprojektin tuotantoputken ja tiedostonhallintamallin perinpohjaisesta läpikäymisestä sekä sen asian tutkimisesta...
Manos, Harry
2016-03-01
Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the TPT theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity well tailored to specific class lessons. Most of the supplies are readily available in the home or at school: rubbing alcohol, a rag, two colors of spray paint, art brushes, and masking tape. The cost of these supplies, if you don't have them, is less than 20.
吕铁雄
2011-01-01
难度:★★★★☆词数:450 建议阅读时间:8分钟 Most people see out of two eyes. This is a basic fact of humanity,but it’s what makes possible the illusion of depth(纵深幻觉) that 3-D movies create. Human eyes are spaced about two inches apart, meaning that each eye gives the brain a slightly different perspective(透视感)on the same object. The brain then uses this variance to quickly determine an object’s distance.
Virtual 3-D Facial Reconstruction
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.
Charting the complete elastic properties of inorganic crystalline compounds
de Jong, Maarten; Chen, Wei; Angsten, Thomas; Jain, Anubhav; Notestine, Randy; Gamst, Anthony; Sluiter, Marcel; Ande, Chaitanya Krishna; Zwaag, Sybrand van der; Plata, Jose J.; Toher, Cormac; Curtarolo, Stefano; Ceder, Gerbrand; Persson, Kristin A.; Asta, Mark
2014-01-01
The elastic constant tensor of an inorganic compound provides a complete description of the response of the material to external stresses in the elastic limit. It thus provides fundamental insight into the nature of the bonding in the material, and it is known to correlate with many mechanical properties. Despite the importance of the elastic constant tensor, it has been measured for a very small fraction of all known inorganic compounds, a situation that limits the ability of materials scien...
Positional Awareness Map 3D (PAM3D)
Hoffman, Monica; Allen, Earl L.; Yount, John W.; Norcross, April Louise
2012-01-01
The Western Aeronautical Test Range of the National Aeronautics and Space Administration s Dryden Flight Research Center needed to address the aging software and hardware of its current situational awareness display application, the Global Real-Time Interactive Map (GRIM). GRIM was initially developed in the late 1980s and executes on older PC architectures using a Linux operating system that is no longer supported. Additionally, the software is difficult to maintain due to its complexity and loss of developer knowledge. It was decided that a replacement application must be developed or acquired in the near future. The replacement must provide the functionality of the original system, the ability to monitor test flight vehicles in real-time, and add improvements such as high resolution imagery and true 3-dimensional capability. This paper will discuss the process of determining the best approach to replace GRIM, and the functionality and capabilities of the first release of the Positional Awareness Map 3D.
Statistical skull models from 3D X-ray images
Berar, M; Bailly, G; Payan, Y; Berar, Maxime; Desvignes, Michel; Payan, Yohan
2006-01-01
We present 2 statistical models of the skull and mandible built upon an elastic registration method of 3D meshes. The aim of this work is to relate degrees of freedom of skull anatomy, as static relations are of main interest for anthropology and legal medicine. Statistical models can effectively provide reconstructions together with statistical precision. In our applications, patient-specific meshes of the skull and the mandible are high-density meshes, extracted from 3D CT scans. All our patient-specific meshes are registrated in a subject-shared reference system using our 3D-to-3D elastic matching algorithm. Registration is based upon the minimization of a distance between the high density mesh and a shared low density mesh, defined on the vertexes, in a multi resolution approach. A Principal Component analysis is performed on the normalised registrated data to build a statistical linear model of the skull and mandible shape variation. The accuracy of the reconstruction is under the millimetre in the shape...
3D Printable Graphene Composite
Wei, Xiaojun; Li, Dong; Jiang, Wei; Gu, Zheming; Wang, Xiaojuan; Zhang, Zengxing; Sun, Zhengzong
2015-07-01
In human being’s history, both the Iron Age and Silicon Age thrived after a matured massive processing technology was developed. Graphene is the most recent superior material which could potentially initialize another new material Age. However, while being exploited to its full extent, conventional processing methods fail to provide a link to today’s personalization tide. New technology should be ushered in. Three-dimensional (3D) printing fills the missing linkage between graphene materials and the digital mainstream. Their alliance could generate additional stream to push the graphene revolution into a new phase. Here we demonstrate for the first time, a graphene composite, with a graphene loading up to 5.6 wt%, can be 3D printable into computer-designed models. The composite’s linear thermal coefficient is below 75 ppm·°C-1 from room temperature to its glass transition temperature (Tg), which is crucial to build minute thermal stress during the printing process.
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. PMID:23635097
3D Ion Temperature Reconstruction
Tanabe, Hiroshi; You, Setthivoine; Balandin, Alexander; Inomoto, Michiaki; Ono, Yasushi
2009-11-01
The TS-4 experiment at the University of Tokyo collides two spheromaks to form a single high-beta compact toroid. Magnetic reconnection during the merging process heats and accelerates the plasma in toroidal and poloidal directions. The reconnection region has a complex 3D topology determined by the pitch of the spheromak magnetic fields at the merging plane. A pair of multichord passive spectroscopic diagnostics have been established to measure the ion temperature and velocity in the reconnection volume. One setup measures spectral lines across a poloidal plane, retrieving velocity and temperature from Abel inversion. The other, novel setup records spectral lines across another section of the plasma and reconstructs velocity and temperature from 3D vector and 2D scalar tomography techniques. The magnetic field linking both measurement planes is determined from in situ magnetic probe arrays. The ion temperature is then estimated within the volume between the two measurement planes and at the reconnection region. The measurement is followed over several repeatable discharges to follow the heating and acceleration process during the merging reconnection.
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
3D Printing of Graphene Aerogels.
Zhang, Qiangqiang; Zhang, Feng; Medarametla, Sai Pradeep; Li, Hui; Zhou, Chi; Lin, Dong
2016-04-01
3D printing of a graphene aerogel with true 3D overhang structures is highlighted. The aerogel is fabricated by combining drop-on-demand 3D printing and freeze casting. The water-based GO ink is ejected and freeze-cast into designed 3D structures. The lightweight (printed graphene aerogel presents superelastic and high electrical conduction. PMID:26861680
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
Photopolymers in 3D printing applications
Pandey, Ramji
2014-01-01
3D printing is an emerging technology with applications in several areas. The flexibility of the 3D printing system to use variety of materials and create any object makes it an attractive technology. Photopolymers are one of the materials used in 3D printing with potential to make products with better properties. Due to numerous applications of photopolymers and 3D printing technologies, this thesis is written to provide information about the various 3D printing technologies with particul...
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 ...
Decoupling braided tensor factors
It is shown that the braided tensor product algebra of two module algebras A1, A2 of a quasitriangular Hopf algebra is equal to the ordinary tensor product algebra of A1 with a subalgebra isomorphic to A2 and commuting with A1. As applications of the theorem the braided tensor product algebras of two or more quantum group covariant quantum space or deformed Heisenberg algebras are considered
RENORM tensor-Pomeron diffractive predictions
Goulianos, K
2016-01-01
Predictions of the elastic scattering, total-inetastic, and total proton-proton cross sections, based on a Regge theory inspired tensor-Pomeron implementation of the RENORM model for hadronic diffraction, are compared to the latest experimental measurements at the LHC. The measured cross sections are in good agreement within the experimental uncertainties of the data and the theoretical uncertainties of the model, reaching down to the ~1% level.
Advanced 3-D Ultrasound Imaging
Rasmussen, Morten Fischer
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...... and removes the need to integrate custom made electronics into the probe. A downside of row-column addressing 2-D arrays is the creation of secondary temporal lobes, or ghost echoes, in the point spread function. In the second part of the scientific contributions, row-column addressing of 2-D arrays...... was investigated. An analysis of how the ghost echoes can be attenuated was presented.Attenuating the ghost echoes were shown to be achieved by minimizing the first derivative of the apodization function. In the literature, a circular symmetric apodization function was proposed. A new apodization layout...
Conducting Polymer 3D Microelectrodes
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.
Cartesian tensors an introduction
Temple, G
2004-01-01
This undergraduate text provides an introduction to the theory of Cartesian tensors, defining tensors as multilinear functions of direction, and simplifying many theorems in a manner that lends unity to the subject. The author notes the importance of the analysis of the structure of tensors in terms of spectral sets of projection operators as part of the very substance of quantum theory. He therefore provides an elementary discussion of the subject, in addition to a view of isotropic tensors and spinor analysis within the confines of Euclidean space. The text concludes with an examination of t
Qian Chen
2008-08-18
The generation, motion, and interaction of dislocations play key roles during the plastic deformation process of crystalline solids. 3D Dislocation Dynamics has been employed as a mesoscale simulation algorithm to investigate the collective and cooperative behavior of dislocations. Most current research on 3D Dislocation Dynamics is based on the solutions available in the framework of classical isotropic elasticity. However, due to some degree of elastic anisotropy in almost all crystalline solids, it is very necessary to extend 3D Dislocation Dynamics into anisotropic elasticity. In this study, first, the details of efficient and accurate incorporation of the fully anisotropic elasticity into 3D discrete Dislocation Dynamics by numerically evaluating the derivatives of Green's functions are described. Then the intrinsic properties of perfect dislocations, including their stability, their core properties and disassociation characteristics, in newly discovered rare earth-based intermetallics and in conventional intermetallics are investigated, within the framework of fully anisotropic elasticity supplemented with the atomistic information obtained from the ab initio calculations. Moreover, the evolution and interaction of dislocations in these intermetallics as well as the role of solute segregation are presented by utilizing fully anisotropic 3D dislocation dynamics. The results from this work clearly indicate the role and the importance of elastic anisotropy on the evolution of dislocation microstructures, the overall ductility and the hardening behavior in these systems.
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
Relations between pressurized triaxial cavities and moment tensor distributions
Claudio Ferrari
2015-09-01
Full Text Available Pressurized cavities are commonly used to compute ground deformation in volcanic areas: the set of available solutions is limited and in some cases the moment tensors inferred from inversion of geodetic data cannot be associated with any of the available models. Two different source models (pure tensile source, TS and mixed tensile/shear source, MS are studied using a boundary element approach for rectangular dislocations buried in a homogeneous elastic medium employing a new C/C++ code which provides a new implementation of the dc3d Okada fortran code. Pressurized triaxial cavities are obtained assigning the overpressure in the middle of each boundary element distributed over the cavity surface. The MS model shows a moment domain very similar to triaxial ellipsoidal cavities. The TS and MS models are also compared in terms of the total volume increment limiting the analysis to cubic sources: the observed discrepancy (~10% is interpreted in terms of the different deformation of the source interior which provides significantly different internal contributions (~30%. Comparing the MS model with a Mogi source with the some volume, the overpressure of the latter must be ~37% greater than the former, in order to obtain the same surface deformation; however the outward expansion and the inner contraction separately differ by ~±10% and the total volume increments differ only by ~2%. Thus, the density estimations for the intrusion extracted from the MS model and the Mogi model are nearly identical.
Group-theoretical method for physical property tensors of quasicrystals
Gong Ping; Hu Cheng-Zheng; Zhou Xiang; Wang Ai-Jun; Miao Ling
2006-01-01
In addition to the phonon variable there is the phason variable in hydrodynamics for quasicrystals. These two kinds of hydrodynamic variables have different transformation properties. The phonon variable transforms under the vector representation, whereas the phason variable transforms under another related representation. Thus, a basis (or a set of basis functions) in the representation space should include such two kinds of variables. This makes it more difficult to determine the physical property tensors of quasicrystals. In this paper the group-theoretical method is given to determine the physical property tensors of quasicrystals. As an illustration of this method we calculate the third-order elasticity tensors of quasicrystals with five-fold symmetry by means of basis functions. It follows that the linear phonon elasticity is isotropic, but the nonlinear phonon elasticity is anisotropic for pentagonal quasicrystals. Meanwhile, the basis functions are constructed for all noncrystallographic point groups of quasicrystals.
Microstructural Assessment of Cancellous Bone Using 3D Microtomography
Cancellous bones have a porous microstructure and can be modeled as linear elastic solid, heterogeneous and anisotropic. Few studies regarding the morphometric analysis of trabecular bone samples with 3D microtomography have been published so far. The technique has spread worldwide for the characterization of trabecular structures in studies related to bone quality and its relationship with metabolic diseases bone like osteoporosis. In our study cancellous bone samples with cubic and cylindrical geometry were extracted from bovine femur were used to investigate the structural arrangement of bone through high resolution x-ray 3D microtomography (μCT). Four trabecular microstructural parameters (tissue volume, bone volume, bone volume fraction and tissue surface) were measured by 2D (stereological method) and 3D morphometric analysis using the software CTan Analyser supplied by the manufacturer of the microtomograph (SkyScan, model 1172, Belgium). The measurements were done in three main directions (superior-inferior, medial-lateral and anterior-posterior) to investigate the correlation between the 2D and 3D morphometric analysis. The results show a high correlation between the analysis. The x-ray 3D microtomography technique has a great potential for the assessment of bone quality.
3D Interpolation Method for CT Images of the Lung
Noriaki Asada
2003-06-01
Full Text Available A 3-D image can be reconstructed from numerous CT images of the lung. The procedure reconstructs a solid from multiple cross section images, which are collected during pulsation of the heart. Thus the motion of the heart is a special factor that must be taken into consideration during reconstruction. The lung exhibits a repeating transformation synchronized to the beating of the heart as an elastic body. There are discontinuities among neighboring CT images due to the beating of the heart, if no special techniques are used in taking CT images. The 3-D heart image is reconstructed from numerous CT images in which both the heart and the lung are taken. Although the outline shape of the reconstructed 3-D heart is quite unnatural, the envelope of the 3-D unnatural heart is fit to the shape of the standard heart. The envelopes of the lung in the CT images are calculated after the section images of the best fitting standard heart are located at the same positions of the CT images. Thus the CT images are geometrically transformed to the optimal CT images fitting best to the standard heart. Since correct transformation of images is required, an Area oriented interpolation method proposed by us is used for interpolation of transformed images. An attempt to reconstruct a 3-D lung image by a series of such operations without discontinuity is shown. Additionally, the same geometrical transformation method to the original projection images is proposed as a more advanced method.
3D multiplexed immunoplasmonics microscopy
Bergeron, Éric; Patskovsky, Sergiy; Rioux, David; Meunier, Michel
2016-07-01
Selective labelling, identification and spatial distribution of cell surface biomarkers can provide important clinical information, such as distinction between healthy and diseased cells, evolution of a disease and selection of the optimal patient-specific treatment. Immunofluorescence is the gold standard for efficient detection of biomarkers expressed by cells. However, antibodies (Abs) conjugated to fluorescent dyes remain limited by their photobleaching, high sensitivity to the environment, low light intensity, and wide absorption and emission spectra. Immunoplasmonics is a novel microscopy method based on the visualization of Abs-functionalized plasmonic nanoparticles (fNPs) targeting cell surface biomarkers. Tunable fNPs should provide higher multiplexing capacity than immunofluorescence since NPs are photostable over time, strongly scatter light at their plasmon peak wavelengths and can be easily functionalized. In this article, we experimentally demonstrate accurate multiplexed detection based on the immunoplasmonics approach. First, we achieve the selective labelling of three targeted cell surface biomarkers (cluster of differentiation 44 (CD44), epidermal growth factor receptor (EGFR) and voltage-gated K+ channel subunit KV1.1) on human cancer CD44+ EGFR+ KV1.1+ MDA-MB-231 cells and reference CD44- EGFR- KV1.1+ 661W cells. The labelling efficiency with three stable specific immunoplasmonics labels (functionalized silver nanospheres (CD44-AgNSs), gold (Au) NSs (EGFR-AuNSs) and Au nanorods (KV1.1-AuNRs)) detected by reflected light microscopy (RLM) is similar to the one with immunofluorescence. Second, we introduce an improved method for 3D localization and spectral identification of fNPs based on fast z-scanning by RLM with three spectral filters corresponding to the plasmon peak wavelengths of the immunoplasmonics labels in the cellular environment (500 nm for 80 nm AgNSs, 580 nm for 100 nm AuNSs and 700 nm for 40 nm × 92 nm AuNRs). Third, the developed
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...
NIF Ignition Target 3D Point Design
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 multiplexed immunoplasmonics microscopy.
Bergeron, Éric; Patskovsky, Sergiy; Rioux, David; Meunier, Michel
2016-07-21
Selective labelling, identification and spatial distribution of cell surface biomarkers can provide important clinical information, such as distinction between healthy and diseased cells, evolution of a disease and selection of the optimal patient-specific treatment. Immunofluorescence is the gold standard for efficient detection of biomarkers expressed by cells. However, antibodies (Abs) conjugated to fluorescent dyes remain limited by their photobleaching, high sensitivity to the environment, low light intensity, and wide absorption and emission spectra. Immunoplasmonics is a novel microscopy method based on the visualization of Abs-functionalized plasmonic nanoparticles (fNPs) targeting cell surface biomarkers. Tunable fNPs should provide higher multiplexing capacity than immunofluorescence since NPs are photostable over time, strongly scatter light at their plasmon peak wavelengths and can be easily functionalized. In this article, we experimentally demonstrate accurate multiplexed detection based on the immunoplasmonics approach. First, we achieve the selective labelling of three targeted cell surface biomarkers (cluster of differentiation 44 (CD44), epidermal growth factor receptor (EGFR) and voltage-gated K(+) channel subunit KV1.1) on human cancer CD44(+) EGFR(+) KV1.1(+) MDA-MB-231 cells and reference CD44(-) EGFR(-) KV1.1(+) 661W cells. The labelling efficiency with three stable specific immunoplasmonics labels (functionalized silver nanospheres (CD44-AgNSs), gold (Au) NSs (EGFR-AuNSs) and Au nanorods (KV1.1-AuNRs)) detected by reflected light microscopy (RLM) is similar to the one with immunofluorescence. Second, we introduce an improved method for 3D localization and spectral identification of fNPs based on fast z-scanning by RLM with three spectral filters corresponding to the plasmon peak wavelengths of the immunoplasmonics labels in the cellular environment (500 nm for 80 nm AgNSs, 580 nm for 100 nm AuNSs and 700 nm for 40 nm × 92 nm AuNRs). Third
ORMGEN3D, 3-D Crack Geometry FEM Mesh Generator
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
3D multiplexed immunoplasmonics microscopy
Bergeron, Éric; Patskovsky, Sergiy; Rioux, David; Meunier, Michel
2016-07-01
Selective labelling, identification and spatial distribution of cell surface biomarkers can provide important clinical information, such as distinction between healthy and diseased cells, evolution of a disease and selection of the optimal patient-specific treatment. Immunofluorescence is the gold standard for efficient detection of biomarkers expressed by cells. However, antibodies (Abs) conjugated to fluorescent dyes remain limited by their photobleaching, high sensitivity to the environment, low light intensity, and wide absorption and emission spectra. Immunoplasmonics is a novel microscopy method based on the visualization of Abs-functionalized plasmonic nanoparticles (fNPs) targeting cell surface biomarkers. Tunable fNPs should provide higher multiplexing capacity than immunofluorescence since NPs are photostable over time, strongly scatter light at their plasmon peak wavelengths and can be easily functionalized. In this article, we experimentally demonstrate accurate multiplexed detection based on the immunoplasmonics approach. First, we achieve the selective labelling of three targeted cell surface biomarkers (cluster of differentiation 44 (CD44), epidermal growth factor receptor (EGFR) and voltage-gated K+ channel subunit KV1.1) on human cancer CD44+ EGFR+ KV1.1+ MDA-MB-231 cells and reference CD44- EGFR- KV1.1+ 661W cells. The labelling efficiency with three stable specific immunoplasmonics labels (functionalized silver nanospheres (CD44-AgNSs), gold (Au) NSs (EGFR-AuNSs) and Au nanorods (KV1.1-AuNRs)) detected by reflected light microscopy (RLM) is similar to the one with immunofluorescence. Second, we introduce an improved method for 3D localization and spectral identification of fNPs based on fast z-scanning by RLM with three spectral filters corresponding to the plasmon peak wavelengths of the immunoplasmonics labels in the cellular environment (500 nm for 80 nm AgNSs, 580 nm for 100 nm AuNSs and 700 nm for 40 nm × 92 nm AuNRs). Third, the developed
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.
A t20 tensor polarimeter using the 3He(d,p)4He reaction as analyzer has been designed and constructed. Upon its calibration, with a deuteron beam of known polarization, it has been used for measurements of the recoil deuteron polarization from πd elastic scattering. The polarimeter was designed such that the cylindrical symmetry required for the polarimeter could be constructed for any given incident deuteron beam geometry, and was aligned independently on such experimental parameters as the position of the beam centroid, beam intensity distribution, etc. There are contributions from it11 and t22, and therefore most likely from t21 as well, is such symmetry is not maintained. It was found that if the incident deuteron intensity distribution is cylindrically symmetric, then contributions from these components can be neglected on average, provided the polarimeter face is larger than the beam size and the beam centroid is placed on the symmetry axis
Yue, Jinlong; Tardieu, Marion; Julea, Felicia; Chami, Linda; Lucidarme, Olivier; Maître, Xavier; Pellot-Barakat, Claire
2015-01-01
Ultrasound Supersonic Shear Wave Elastog-raphy (SSWE) as well as Magnetic Resonance Elastography (MRE) allow accessing the mechanical properties of human tissues. SSWE is usually performed using a 2D probe. 3D SSWE is now available but needs to be validated. We compared 3D SSWE with both 2D SSWE and MRE which is inherently 3D on a breast phantom. We found that 3D SSWE is reproducible and provides elasticity estimates comparable to those obtained with the validated 2D SSWE. We also showed that...
The advanced simulation of fatigue crack growth in complex 3D structures
Kolk, Karsten; Kuhn, Guenther [Institute of Applied Mechanics, Erlangen (Germany)
2006-12-15
An advanced incremental crack growth algorithm for the three-dimensional (3D) simulation of fatigue crack growth in complex 3D structures with linear elastic material behavior is presented. To perform the crack growth simulation as effectively as possible an accurate stress analysis is done by the boundary-element method (BEM) in terms of the 3D dual BEM. The question concerning a reliable 3D crack growth criterion is answered based on experimental observations. All criteria under consideration are numerically realized by a predictor-corrector procedure. The agreement between numerically determined and experimentally observed crack fronts will be shown on both fracture specimens and an industrial application. (orig.)
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
3D Printing Making the Digital Real .
Miss Prachi More
2013-07-01
Full Text Available 3D printing is quickly expanding field, with the popularity and uses for 3D printers growing every day. 3D printing can be used to prototype, create replacement parts, and is even versatile enough to print prostheses and medical implants. It will have a growing impact on our world, as more and more people gain access to these amazing machines.[1] In this article, we would like to attempt to give an introduction of the technology. 3Dimensions printing is a method of converting a virtual 3D model into a physical object. 3D printing is a category of rapid prototyping technology. 3D printers typically work by printing successive layers on top of the previous to build up a three dimensional object. 3D printing is a revolutionary method for creating 3D models with the use of inkjet technology.[7
Sliding Adjustment for 3D Video Representation
Galpin Franck
2002-01-01
Full Text Available This paper deals with video coding of static scenes viewed by a moving camera. We propose an automatic way to encode such video sequences using several 3D models. Contrary to prior art in model-based coding where 3D models have to be known, the 3D models are automatically computed from the original video sequence. We show that several independent 3D models provide the same functionalities as one single 3D model, and avoid some drawbacks of the previous approaches. To achieve this goal we propose a novel algorithm of sliding adjustment, which ensures consistency of successive 3D models. The paper presents a method to automatically extract the set of 3D models and associate camera positions. The obtained representation can be used for reconstructing the original sequence, or virtual ones. It also enables 3D functionalities such as synthetic object insertion, lightning modification, or stereoscopic visualization. Results on real video sequences are presented.
3D Flash LIDAR Space Laser Project
National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) is a small business that has developed 3D Flash LIDAR systems for space and terrestrial applications. 3D Flash LIDAR is...
3D Additive Manufacturing Symposium & Workshop
Unver, Ertu; Taylor, Andrew
2015-01-01
The IMI /3M BIC 3D Additive Manufacturing Symposium and Workshop was hosted by 3M Buckley Innovation Centre on March 17th 2015. The event was attended by the major players in precision engineering, 3D additive design and manufacturing: Representatives from EOS, Renishaw, HK 3D Printing IMI Plc Senior Management team, design engineers, programmers and academics from the University of Huddersfield School of Art Design & Architecture, 3M Buckley centre 3D printing management and designers shared...
Face Detection with a 3D Model
Barbu, Adrian; Lay, Nathan; Gramajo, Gary
2014-01-01
This paper presents a part-based face detection approach where the spatial relationship between the face parts is represented by a hidden 3D model with six parameters. The computational complexity of the search in the six dimensional pose space is addressed by proposing meaningful 3D pose candidates by image-based regression from detected face keypoint locations. The 3D pose candidates are evaluated using a parameter sensitive classifier based on difference features relative to the 3D pose. A...
3D PHOTOGRAPHS IN CULTURAL HERITAGE
Schuhr, W.; J. D. Lee; Kiel, St.
2013-01-01
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 interpret...
3D textiles for composite reinforcements
Fangueiro, Raúl; Mingxing, Z.; Hong, H; Soutinho, Hélder Filipe Cunha; Gonçalves, P.; Araújo, Mário Duarte de
2010-01-01
This paper presents an overview on the last developments on 3D textile structures for composite reinforcements. The application of innovative 3D shaped weft-knitted preforms in GFRP tube joints is presented and discussed. Moreover, the mechanical behaviour of 3D hybrid basalt fiber reinforced composite material sis also presented and 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
Senovilla, J M M
2000-01-01
A purely algebraic construction of super-energy tensors for arbitrary fields is presented in any dimensions. These tensors have good mathematical and physical properties, and they can be used in any theory having as basic arena an n-dimensional manifold with a metric of Lorentzian signature. In general, the completely timelike component of these s-e tensors has the mathematical features of an energy density: they are positive definite and satisfy the dominant property. Similarly, the super-momentum vectors have mathematical properties of s-e flux vectors. The classical Bel-Robinson tensor is included in our general definition. The energy-momentum and super-energy tensors of physical fields are also obtained, and the procedure is illustrated by writing down these tensors explicitly for the cases of scalar, electromagnetic, and Proca fields. Moreover, `(super)$^k$-energy' tensors are defined and shown to be meaningful and in agreement for the different physical fields. In flat spacetimes, they provide infinitel...
3-D Perspective Pasadena, California
2000-01-01
This perspective view shows the western part of the city of Pasadena, California, looking north towards the San Gabriel Mountains. Portions of the cities of Altadena and La Canada, Flintridge are also shown. The image was created from three datasets: the Shuttle Radar Topography Mission (SRTM) supplied the elevation data; Landsat data from November 11, 1986 provided the land surface color (not the sky) and U.S. Geological Survey digital aerial photography provides the image detail. The Rose Bowl, surrounded by a golf course, is the circular feature at the bottom center of the image. The Jet Propulsion Laboratory is the cluster of large buildings north of the Rose Bowl at the base of the mountains. A large landfill, Scholl Canyon, is the smooth area in the lower left corner of the scene. This image shows the power of combining data from different sources to create planning tools to study problems that affect large urban areas. In addition to the well-known earthquake hazards, Southern California is affected by a natural cycle of fire and mudflows. Wildfires strip the mountains of vegetation, increasing the hazards from flooding and mudflows for several years afterwards. Data such as shown on this image can be used to predict both how wildfires will spread over the terrain and also how mudflows will be channeled down the canyons. The Shuttle Radar Topography Mission (SRTM), launched on February 11, 2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission was designed to collect three dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency
Esiselvitys elintarvikkeiden 3D-tulostamisesta
Teva, Arno
2015-01-01
Opinnäytetyön tavoitteena oli laatia esiselvitys 3D-tulostamisesta elintarvikealalla. 3D-tulostaminen on uusi ja jatkuvasti kehittyvä ala, joka tulee vaikuttamaan myös elintarvikealan kehittymiseen. Työn tarkoituksena oli selvittää elintarvikenäkökulmasta 3D-tulostamiseen liittyviä tekijöitä. Aiheen toimeksiantajana oli Hämeen ammattikorkeakoulu ja kohderyhmänä elintarvikealan Pk-yritykset. Opinnäytetyössä esitellään yleisimpiä 3D-tulostusmenetelmiä ja selvitetään 3D-tulostamista tietokone...
Črešnik, Igor
2015-01-01
V diplomskem delu predstavljamo pripravo modela na 3D-tisk. V prvem delu smo preleteli zgodovino tiska. Predstavili smo tehnologijo 3D-tiska ter različne tehnike tiskanja, ki jih uporabljajo določeni tiskalniki. V nadaljevanju smo pregledali različne tipe 3D-tiskalnikov, ki se uporabljajo za domačo ali komercialno uporabo ter izpostavili njihove prednosti in slabosti. V zadnjem delu diplomskega dela smo na praktičnem primeru 3D-modela hiše prikazali proces priprave modela za 3D-tisk. Pri delu...
3D-tulostimien tutkiminen painotalolle
Toivonen, Aleksi
2014-01-01
Opinnäytetyön tavoitteena oli perehtyä 3D-tulostamiseen ja tutkia painotaloon sopivia 3D-tulostimia ja 3D-tulostamiseen liittyviä tekniikoita. Opinnäytetyön tavoitteena oli myös pohtia painotalolle mahdollisia 3D-tulostamiseen liittyviä tuotekonsepteja yrityksille ja yksityisille kuluttajille. Painoalan yrityksen tarkoituksena on sijoittaa lähitulevaisuudessa 3D-tulostimeen, joten opinnäytetyö oli ajankohtainen tutkimustyö yritykselle. Opinnäytetyön toimeksiantajana toimi painoalan yritys. ...
BUILDING A HOMEMADE 3D PRINTER
Tunc, Baran
2015-01-01
3D printing has been attracted much attention around the world due to its high potential of new application fields. In this respect, developing and inventing new filament materials for 3D printers or new techniques of 3D printing are the main interest of the many materials scientists. This paper reports a comprehensive overview of 3D printing followed by a summary of my ongoing study of building a composite homemade 3D printer. At this stage of this study, a CNC router was successfully conver...
Taylor, Andrew; Unver, Ertu
2015-01-01
This 3D Printing our Future:Now talk and visual presentation was given to delegates at the IMI 3D Workshop held at 3M Buckley Innovation Centre on 17th March 2015. The event was hosted by 3Mbuckley Innovation Centre for IMI plc a global engineering company, 3M, and leading 3D additive manufacturing technology providers: EOS, Renishaw and HK 3D printing to disseminate and share their experience on the latest 3D additive design and manufacturing technologies available to the engineering an...
Investigating Mobile Stereoscopic 3D Touchscreen Interaction
Colley, Ashley; Hakkila, Jonna; SCHOENING, Johannes; Posti, Maaret
2013-01-01
3D output is no longer limited to large screens in cinemas or living rooms. Nowadays more and more mobile devices are equipped with autostereoscopic 3D (S3D) touchscreens. As a consequence interaction with 3D content now also happens whilst users are on the move. In this paper we carried out a user study with 27 participants to assess how mobile interaction, i.e. whilst walking, with mobile S3D devices, differs from interaction with 2D mobile touchscreens. We investigate the difference in tou...
Scopigno, Roberto
2005-01-01
Nearly all of our cultural heritage is inherently three-dimensional. Recent hard- and software developments enabled 3D computer graphics to be one of the most powerful means to represent complex data sets. The ViHAP3D project (ViHAP3D is an acronym for Virtual Heritage - High Quality 3D Acquisition and Presentation) aimed therefore at preserving, presenting, accessing, and promoting cultural heritage using interactive, high-quality 3D graphics. The vision of the project was to create an exact...
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.
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
Web-based interactive visualization of 3D video mosaics using X3D standard
CHON Jaechoon; LEE Yang-Won; SHIBASAKI Ryosuke
2006-01-01
We present a method of 3D image mosaicing for real 3D representation of roadside buildings, and implement a Web-based interactive visualization environment for the 3D video mosaics created by 3D image mosaicing. The 3D image mosaicing technique developed in our previous work is a very powerful method for creating textured 3D-GIS data without excessive data processing like the laser or stereo system. For the Web-based open access to the 3D video mosaics, we build an interactive visualization environment using X3D, the emerging standard of Web 3D. We conduct the data preprocessing for 3D video mosaics and the X3D modeling for textured 3D data. The data preprocessing includes the conversion of each frame of 3D video mosaics into concatenated image files that can be hyperlinked on the Web. The X3D modeling handles the representation of concatenated images using necessary X3D nodes. By employing X3D as the data format for 3D image mosaics, the real 3D representation of roadside buildings is extended to the Web and mobile service systems.
Feature Surfaces in Symmetric Tensor Fields Based on Eigenvalue Manifold.
Palacios, Jonathan; Yeh, Harry; Wang, Wenping; Zhang, Yue; Laramee, Robert S; Sharma, Ritesh; Schultz, Thomas; Zhang, Eugene
2016-03-01
Three-dimensional symmetric tensor fields have a wide range of applications in solid and fluid mechanics. Recent advances in the (topological) analysis of 3D symmetric tensor fields focus on degenerate tensors which form curves. In this paper, we introduce a number of feature surfaces, such as neutral surfaces and traceless surfaces, into tensor field analysis, based on the notion of eigenvalue manifold. Neutral surfaces are the boundary between linear tensors and planar tensors, and the traceless surfaces are the boundary between tensors of positive traces and those of negative traces. Degenerate curves, neutral surfaces, and traceless surfaces together form a partition of the eigenvalue manifold, which provides a more complete tensor field analysis than degenerate curves alone. We also extract and visualize the isosurfaces of tensor modes, tensor isotropy, and tensor magnitude, which we have found useful for domain applications in fluid and solid mechanics. Extracting neutral and traceless surfaces using the Marching Tetrahedra method can cause the loss of geometric and topological details, which can lead to false physical interpretation. To robustly extract neutral surfaces and traceless surfaces, we develop a polynomial description of them which enables us to borrow techniques from algebraic surface extraction, a topic well-researched by the computer-aided design (CAD) community as well as the algebraic geometry community. In addition, we adapt the surface extraction technique, called A-patches, to improve the speed of finding degenerate curves. Finally, we apply our analysis to data from solid and fluid mechanics as well as scalar field analysis. PMID:26441450
Tensor Network Skeletonization
Ying, Lexing
2016-01-01
We introduce a new coarse-graining algorithm, tensor network skeletonization, for the numerical computation of tensor networks. This approach utilizes a structure-preserving skeletonization procedure to remove short-range correlations effectively at every scale. This approach is first presented in the setting of 2D statistical Ising model and is then extended to higher dimensional tensor networks and disordered systems. When applied to the Euclidean path integral formulation, this approach also gives rise to new efficient representations of the ground states for 1D and 2D quantum Ising models.
Hur, J.; Chun, Y.D.; Lee, J.; Hyun, D.S. [Hanyang Univ., Seoul (Korea, Republic of). Dept. of Electrical Engineering
1998-09-01
The distribution of radial force density in brushless permanent magnet DC motor is not uniform in axial direction. The analysis of radial force density has to consider the 3-D shape of teeth and overhand, because the radial force density causes vibration and acts on the surface of teeth inconstantly. For the analysis, a new 3-D equivalent magnetic circuit network method is used to account the rotor movement without remesh. The radial force density is calculated and analyzed by Maxwell stress tensor and discrete Fourier transform (DFT) respectively. The results of 3-D equivalent magnetic circuit method have been compared with the results of 3-D FEM.
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.
Jean Imbs; Isabelle Mejean
2010-01-01
We estimate the aggregate export and import price elasticities implied by a Constant Elasticity of Substitution (CES) demand system, for more than 30 countries at various stages of development. Trade elasticities are given by weighted averages of sector-specific elasticities of substitution, that we estimate structurally. Both weights and substitution elasticities can be chosen to compute the response of trade to specific shocks to relative prices, bilateral or global. We document considerabl...
3D laptop for defense applications
Edmondson, Richard; Chenault, David
2012-06-01
Polaris Sensor Technologies has developed numerous 3D display systems using a US Army patented approach. These displays have been developed as prototypes for handheld controllers for robotic systems and closed hatch driving, and as part of a TALON robot upgrade for 3D vision, providing depth perception for the operator for improved manipulation and hazard avoidance. In this paper we discuss the prototype rugged 3D laptop computer and its applications to defense missions. The prototype 3D laptop combines full temporal and spatial resolution display with the rugged Amrel laptop computer. The display is viewed through protective passive polarized eyewear, and allows combined 2D and 3D content. Uses include robot tele-operation with live 3D video or synthetically rendered scenery, mission planning and rehearsal, enhanced 3D data interpretation, and simulation.
User-centered 3D geovisualisation
Nielsen, Anette Hougaard
2004-01-01
3D Geovisualisation is a multidisciplinary science mainly utilizing geographically related data, developing software systems for 3D visualisation and producing relevant models. In this paper the connection between geoinformation stored as 3D objects and the end user is of special interest....... In a broader perspective, the overall aim is to develop a language in 3D Geovisualisation gained through usability projects and the development of a theoretical background. A conceptual level of user-centered 3D Geovisualisation is introduced by applying a categorisation originating from Virtual Reality....... The conceptual level is used to structure and organise user-centered 3D Geovisualisation into four categories: representation, rendering, interface and interaction. The categories reflect a process of development of 3D Geovisualisation where objects can be represented verisimilar to the real world...
3D Chaotic Functions for Image Encryption
Pawan N. Khade
2012-05-01
Full Text Available This paper proposes the chaotic encryption algorithm based on 3D logistic map, 3D Chebyshev map, and 3D, 2D Arnolds cat map for color image encryption. Here the 2D Arnolds cat map is used for image pixel scrambling and 3D Arnolds cat map is used for R, G, and B component substitution. 3D Chebyshev map is used for key generation and 3D logistic map is used for image scrambling. The use of 3D chaotic functions in the encryption algorithm provide more security by using the, shuffling and substitution to the encrypted image. The Chebyshev map is used for public key encryption and distribution of generated private keys.
Preservation of tensor sum and tensor product continuous functions
C. S. Kubrusly
2011-02-01
Full Text Available This note deals with preservation of tensor sum and tensor product of Hilbert space operators. Basic operations with tensor sum are presented. The main result addresses to the problem of transferring properties from a pair of operators to their tensor sum and to their tensor product. Sufficient conditions are given to ensure that properties preserved by ordinary sum and ordinary product are preserved by tensor sum and tensor product, which are equally relevant for both finite-dimensional and infinite-dimensional spaces.
Development Of 3D Woven Fabric Based Pressure Switch
Shaker Khubab
2015-06-01
Full Text Available This paper introduces a 3D woven fabric-based approach for the development of pressure switch. A fabric substrate, being elastic and extendable is very useful in addition to its high breaking strength and low cost. The developed resistive-type switch is based on the multilayer interlock 3D fabrics. In the top and bottom layers, certain number of conductive yarns are woven separated by cotton yarns in both transversal and thickness direction. Application of pressure makes the layers of conductive yarn to come in contact, resulting in a short circuit, which may be recorded using multi-meters. Removing the pressure cause the connection points to separate away and it depends on the weave design. Such switch can be used as an on/off switch for usage in security systems, can be sewn into carpets and wearable garments for a number of purposes.
COMPACTLY SUPPORTED NON-TENSOR PRODUCT FORM TWO-DIMENSION WAVELET FINITE ELEMENT
JIN Jian-ming; XUE Peng-xiang; XU Ying-xiang; ZHU Ya-li
2006-01-01
Some theorems of compactly supported non-tensor product form two-dimension Daubechies wavelet were analysed carefully. Compactly supported non-tensor product form two-dimension wavelet was constructed, then non-tensor product form two dimension wavelet finite element was used to solve the deflection problem of elastic thin plate.The error order was researched. A numerical example was given at last.
Comprehensive Aerodynamic Analysis of a 10 MW Wind Turbine Rotor Using 3D CFD
Zahle, Frederik; Bak, Christian; Sørensen, Niels N.;
2014-01-01
This article describes a comprehensive aerodynamic analysis carried out on the DTU 10 MW Reference Wind Turbine (DTU 10MW RWT), in which 3D CFD simulations were used to analyse the rotor performance and derive airfoil aerodynamic characteristics for use in aero-elastic simulation tools. The 3D CFD...... airfoil data derived using the Azimuthal Averaging Technique (AAT) was compared to airfoil data based on 2D CFD simulations on airfoil sections in combination with an array of 3D-correction engineering models, which indicated that the model by Chaviaropoulos and Hansen was in best agreement with the 3D...... CFD predictions. BEM simulations on the DTU 10MW RWT using the AAT-based airfoil data were carried out and compared to BEM simulations using the original airfoil data and the 3D CFD results, which showed clear improvements, particularly on the inner part of the rotor. Finally, 3D unsteady Detached...
Symmetric Tensor Decomposition
Brachat, Jerome; Comon, Pierre; Mourrain, Bernard;
2010-01-01
We present an algorithm for decomposing a symmetric tensor, of dimension n and order d, as a sum of rank-1 symmetric tensors, extending the algorithm of Sylvester devised in 1886 for binary forms. We recall the correspondence between the decomposition of a homogeneous polynomial in n variables of...... polynomial equations of small degree in non-generic cases. We propose a new algorithm for symmetric tensor decomposition, based on this characterization and on linear algebra computations with Hankel matrices. The impact of this contribution is two-fold. First it permits an efficient computation of the...... decomposition of any tensor of sub-generic rank, as opposed to widely used iterative algorithms with unproved global convergence (e.g. Alternate Least Squares or gradient descents). Second, it gives tools for understanding uniqueness conditions and for detecting the rank....
Chung, Daniel J H
2016-01-01
We reformulate gauge theories in analogy with the vierbein formalism of general relativity. More specifically, we reformulate gauge theories such that their gauge dynamical degrees of freedom are local fields that transform linearly under the dual representation of the charged matter field. These local fields, which naively have the interpretation of non-local operators similar to Wilson lines, satisfy constraint equations. A set of basis tensor fields are used to solve these constraint equations, and their field theory is constructed. A new local symmetry in terms of the basis tensor fields is used to make this field theory local and maintain a Hamiltonian that is bounded from below. The field theory of the basis tensor fields is what we call the basis tensor gauge theory.
Optimized designs for 2D and 3D thermoelastic structures
Pedersen, Pauli; Pedersen, Niels Leergaard
2011-01-01
energy density (or uniform von Mises stress) is presented and applied, and it is shown by examples that the obtained designs are close to fulfilling also strength maximization. Explicit formulas for equivalent thermoelastic loads in 2D and 3D finite element analysis are derived and applied, including the...... proved for thermoelastic structures by compliance sensitivity analysis that return localized determination of sensitivities.The compliance is not identical to the total elastic energy (twice strain energy). An explicit formula for the difference is derived and numerically illustrated with examples. In...
Interactive Volume Rendering of Diffusion Tensor Data
Hlawitschka, Mario; Weber, Gunther; Anwander, Alfred; Carmichael, Owen; Hamann, Bernd; Scheuermann, Gerik
2007-03-30
As 3D volumetric images of the human body become an increasingly crucial source of information for the diagnosis and treatment of a broad variety of medical conditions, advanced techniques that allow clinicians to efficiently and clearly visualize volumetric images become increasingly important. Interaction has proven to be a key concept in analysis of medical images because static images of 3D data are prone to artifacts and misunderstanding of depth. Furthermore, fading out clinically irrelevant aspects of the image while preserving contextual anatomical landmarks helps medical doctors to focus on important parts of the images without becoming disoriented. Our goal was to develop a tool that unifies interactive manipulation and context preserving visualization of medical images with a special focus on diffusion tensor imaging (DTI) data. At each image voxel, DTI provides a 3 x 3 tensor whose entries represent the 3D statistical properties of water diffusion locally. Water motion that is preferential to specific spatial directions suggests structural organization of the underlying biological tissue; in particular, in the human brain, the naturally occuring diffusion of water in the axon portion of neurons is predominantly anisotropic along the longitudinal direction of the elongated, fiber-like axons [MMM+02]. This property has made DTI an emerging source of information about the structural integrity of axons and axonal connectivity between brain regions, both of which are thought to be disrupted in a broad range of medical disorders including multiple sclerosis, cerebrovascular disease, and autism [Mos02, FCI+01, JLH+99, BGKM+04, BJB+03].
Elasticity of plagioclase feldspars
Brown, J. Michael; Angel, Ross J.; Ross, Nancy L.
2016-02-01
Elastic properties are reported for eight plagioclase feldspars that span compositions from albite (NaSi3AlO8) to anorthite (CaSi2Al2O8). Surface acoustic wave velocities measured using Impulsive Stimulated Light Scattering and compliance sums from high-pressure X-ray compression studies accurately determine all 21 components of the elasticity tensor for these triclinic minerals. The overall pattern of elasticity and the changes in individual elastic components with composition can be rationalized on the basis of the evolution of crystal structures and chemistry across this solid-solution join. All plagioclase feldspars have high elastic anisotropy; a* (the direction perpendicular to the b and c axes) is the softest direction by a factor of 3 in albite. From albite to anorthite the stiffness of this direction undergoes the greatest change, increasing twofold. Small discontinuities in the elastic components, inferred to occur between the three plagioclase phases with distinct symmetry (C1>¯, I1>¯, and P1>¯), appear consistent with the nature of the underlying conformation of the framework-linked tetrahedra and the associated structural changes. Measured body wave velocities of plagioclase-rich rocks, reported over the last five decades, are consistent with calculated Hill-averaged velocities using the current moduli. This confirms long-standing speculation that previously reported elastic moduli for plagioclase feldspars are systematically in error. The current results provide greater assurance that the seismic structure of the middle and lower crusts can be accurately estimated on the basis of specified mineral modes, chemistry, and fabric.
3-D Technology Approaches for Biological Ecologies
Liu, Liyu; Austin, Robert; U. S-China Physical-Oncology Sciences Alliance (PS-OA) Team
Constructing three dimensional (3-D) landscapes is an inevitable issue in deep study of biological ecologies, because in whatever scales in nature, all of the ecosystems are composed by complex 3-D environments and biological behaviors. Just imagine if a 3-D technology could help complex ecosystems be built easily and mimic in vivo microenvironment realistically with flexible environmental controls, it will be a fantastic and powerful thrust to assist researchers for explorations. For years, we have been utilizing and developing different technologies for constructing 3-D micro landscapes for biophysics studies in in vitro. Here, I will review our past efforts, including probing cancer cell invasiveness with 3-D silicon based Tepuis, constructing 3-D microenvironment for cell invasion and metastasis through polydimethylsiloxane (PDMS) soft lithography, as well as explorations of optimized stenting positions for coronary bifurcation disease with 3-D wax printing and the latest home designed 3-D bio-printer. Although 3-D technologies is currently considered not mature enough for arbitrary 3-D micro-ecological models with easy design and fabrication, I hope through my talk, the audiences will be able to sense its significance and predictable breakthroughs in the near future. This work was supported by the State Key Development Program for Basic Research of China (Grant No. 2013CB837200), the National Natural Science Foundation of China (Grant No. 11474345) and the Beijing Natural Science Foundation (Grant No. 7154221).
FROM 3D MODEL DATA TO SEMANTICS
My Abdellah Kassimi
2012-01-01
Full Text Available The semantic-based 3D models retrieval systems have become necessary since the increase of 3D modelsdatabases. In this paper, we propose a new method for the mapping problem between 3D model data andsemantic data involved in semantic based retrieval for 3D models given by polygonal meshes. First, wefocused on extracting invariant descriptors from the 3D models and analyzing them to efficient semanticannotation and to improve the retrieval accuracy. Selected shape descriptors provide a set of termscommonly used to describe visually a set of objects using linguistic terms and are used as semanticconcept to label 3D model. Second, spatial relationship representing directional, topological anddistance relationships are used to derive other high-level semantic features and to avoid the problem ofautomatic 3D model annotation. Based on the resulting semantic annotation and spatial concepts, anontology for 3D model retrieval is constructed and other concepts can be inferred. This ontology is usedto find similar 3D models for a given query model. We adopted the query by semantic example approach,in which the annotation is performed mostly automatically. The proposed method is implemented in our3D search engine (SB3DMR, tested using the Princeton Shape Benchmark Database.
A hybrid method for the computation of quasi-3D seismograms.
Masson, Yder; Romanowicz, Barbara
2013-04-01
Green's functions are computed using 2D SEM simulation in a 1D Earth model. Such seismograms account for the 3D structure inside the region of interest in a quasi-exact manner. Later we plan to extrapolate the misfit function computed from such seismograms at the stations back into the SEM region in order to compute local adjoint kernels. This opens a new path toward regional adjoint tomography into the deep Earth. Capdeville, Y., et al. (2002). "Coupling the spectral element method with a modal solution for elastic wave propagation in global Earth models." Geophysical Journal International 152(1): 34-67. Lekic, V. and B. Romanowicz (2011). "Inferring upper-mantle structure by full waveform tomography with the spectral element method." Geophysical Journal International 185(2): 799-831. Nissen-Meyer, T., et al. (2007). "A two-dimensional spectral-element method for computing spherical-earth seismograms-I. Moment-tensor source." Geophysical Journal International 168(3): 1067-1092. Robertsson, J. O. A. and C. H. Chapman (2000). "An efficient method for calculating finite-difference seismograms after model alterations." Geophysics 65(3): 907-918. Tape, C., et al. (2009). "Adjoint tomography of the southern California crust." Science 325(5943): 988-992.
Analysis and modeling of coupled thermo-hydro-mechanical phenomena in 3D fractured media
negligible (matrix permeability may embody some finer fracturing in addition to pore space). When fracture flow is complemented by significant matrix permeability, it may be possible to avoid empirical connectivity-based corrections, which are used in the literature to account for non-percolation effects. The superposition approach is also applied here to coupled Hydro-Mechanical problems to obtain the equivalent coefficients of the 3D fractured medium, including the permeability tensor, but also elastic stiffness or compliance coefficients, as well as pressure-strain coupling coefficients (Biot). Finally, these results are used to develop a continuum equivalent model for 3D coupled Thermo-Hydro-Mechanics, including: hydro-mechanical coupling via tensorial Biot equations (non-orthotropic), a Darcian flow in an equivalent porous medium (anisotropic permeability), as well as thermal stresses and heat transport by diffusion and convection, taking into account the thermal expansivity of water. Transient simulations of the excavation of the FEBEX gallery, and of the heating due to hypothetical radioactive waste canisters, are conducted using the Comsol Multiphysics software (3D finite elements). The results of numerical simulations are analyzed for different cases and different ways of stressing the system. Finally, preliminary comparisons of simulations with time series data collected during the 'In-Situ Test' of FEBEX yield encouraging results. (author)
The Physics and Applications of a 3D Plasmonic Nanostructure
Terranova, Brandon B.
In this work, the dynamics of electromagnetic field interactions with free electrons in a 3D metallic nanostructure is evaluated theoretically. This dissertation starts by reviewing the relevant fundamentals of plasmonics and modern applications of plasmonic systems. Then, motivated by the need to have a simpler way of understanding the surface charge dynamics on complex plasmonic nanostructures, a new plasmon hybridization tree method is introduced. This method provides the plasmonicist with an intuitive way to determine the response of free electrons to incident light in complex nanostructures within the electrostatic regime. Next, a novel 3D plasmonic nanostructure utilizing reflective plasmonic coupling is designed to perform biosensing and plasmonic tweezing applications. By applying analytical and numerical methods, the effectiveness of this nanostructure at performing these applications is determined from the plasmonic response of the nanostructure to an excitation beam of coherent light. During this analysis, it was discovered that under certain conditions, this 3D nanostructure exhibits a plasmonic Fano resonance resulting from the interference of an in-plane dark mode and an out-of-plane bright mode. In evaluating this nanostructure for sensing changes in the local dielectric environment, a figure of merit of 68 is calculated, which is competitive with current localized surface plasmon resonance refractometric sensors. By evaluating the Maxwell stress tensor on a test particle in the vicinity of the nanostructure, it was found that under the right conditions, this plasmonic nanostructure design is capable of imparting forces greater than 10.5 nN on dielectric objects of nanoscale dimensions. The results obtained in these studies provides new routes to the design and engineering of 3D plasmonic nanostructures and Fano resonances in these systems. In addition, the nanostructure presented in this work and the design principles it utilizes have shown
Holography of 3D Asymptotically Flat Black Holes
Fareghbal, Reza
2014-01-01
We study the asymptotically flat rotating hairy black hole solution of a three-dimensional gravity theory which is given by taking flat-space limit (zero cosmological constant limit) of New Massive Gravity (NMG). We propose that the dual field theory of the flat-space limit of NMG can be described by a Contracted Conformal Field Theory (CCFT). Using Flat/CCFT correspondence we construct a stress tensor which yields the conserved charges of the asymptotically flat black hole solution. Furthermore, by taking appropriate limit of the Cardy formula in the parent CFT, we find a Cardy-like formula which reproduces the Wald's entropy of the 3D asymptotically flat black hole.
Massive fermion model in 3d and higher spin currents
Bonora, L; Prester, P Dominis; de Souza, B Lima; Smolic, I
2016-01-01
We analyze the 3d free massive fermion theory coupled to external sources. The presence of a mass explicitly breaks parity invariance. We calculate two- and three-point functions of a gauge current and the energy momentum tensor and, for instance, obtain the well-known result that in the IR limit (but also in the UV one) we reconstruct the relevant CS action. We then couple the model to higher spin currents and explicitly work out the spin 3 case. In the UV limit we obtain an effective action which was proposed many years ago as a possible generalization of spin 3 CS action. In the IR limit we derive a different higher spin action. This analysis can evidently be generalized to higher spins. We also discuss the conservation and properties of the correlators we obtain in the intermediate steps of our derivation.
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 it
Arvekari, Lassi
2013-01-01
Opinnäytetyön tavoitteena on selvittää 3D-tulostustekniikan perusteita ja 3D-tulostuksen nykytilannetta. 3D-tulostukseen sopivien mallien luomista tutkitaan ja mallin tekemiseen on etsitty toimivia ohjesääntöjä. Tärkeä osa työtä on tutkia mitä vaiheita 3D-tulostimen hankinnassa kotikäyttöön tulee vastaan. Käytännön kokeita varten opinnäytetyössä on case Printrbot, jossa on tutustuttu edulliseen 3D-tulostuslaitteeseen kokoonpanosta lähtien. Työn kuluessa selvisi että edulliset 3D-tulos...
Identification of the transition arrays 3d74s-3d74p in Br X and 3d64s-3d64p in Br XI
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 3d74s-3d74p transitions in Br X, from which 16 levels of the previously unknown 3d74s configuration could be established. We have also added 6 new 3d74p levels to the 99 previously known. For Br XI we have classified 9 lines as 3d64s-3d64p combinations. The line identifications have been corroborated by isoelectronic comparisons and theoretical calculations using the superposition-of-configurations technique. (orig.)
3D Dynamic Echocardiography with a Digitizer
Oshiro, Osamu; Matani, Ayumu; Chihara, Kunihiro
1998-05-01
In this paper,a three-dimensional (3D) dynamic ultrasound (US) imaging system,where a US brightness-mode (B-mode) imagetriggered with an R-wave of electrocardiogram (ECG)was obtained with an ultrasound diagnostic deviceand the location and orientation of the US probewere simultaneously measured with a 3D digitizer, is described.The obtained B-mode imagewas then projected onto a virtual 3D spacewith the proposed interpolation algorithm using a Gaussian operator.Furthermore, a 3D image was presented on a cathode ray tube (CRT)and stored in virtual reality modeling language (VRML).We performed an experimentto reconstruct a 3D heart image in systole using this system.The experimental results indicatethat the system enables the visualization ofthe 3D and internal structure of a heart viewed from any angleand has potential for use in dynamic imaging,intraoperative ultrasonography and tele-medicine.
Rubber Impact on 3D Textile Composites
Heimbs, Sebastian; Van Den Broucke, Björn; DUPLESSIS KERGOMARD, Yann; Dau, Frédéric; MALHERBE, Benoit
2012-01-01
A low velocity impact study of aircraft tire rubber on 3D textile-reinforced composite plates was performed experimentally and numerically. In contrast to regular unidirectional composite laminates, no delaminations occur in such a 3D textile composite. Yarn decohesions, matrix cracks and yarn ruptures have been identified as the major damage mechanisms under impact load. An increase in the number of 3D warp yarns is proposed to improve the impact damage resistance. The characteristic o...
Spatial data modelling for 3D GIS
Abdul-Rahman, Alias
2007-01-01
This book covers fundamental aspects of spatial data modelling specifically on the aspect of three-dimensional (3D) modelling and structuring. Realisation of ""true"" 3D GIS spatial system needs a lot of effort, and the process is taking place in various research centres and universities in some countries. The development of spatial data modelling for 3D objects is the focus of this book.
MMDB: 3D structures and macromolecular interactions
Madej, Thomas; Addess, Kenneth J.; Fong, Jessica H.; Geer, Lewis Y.; Geer, Renata C.; Lanczycki, Christopher J; Liu, Chunlei; Lu, Shennan; Marchler-Bauer, Aron; Panchenko, Anna R.; Chen, Jie; Thiessen, Paul A; Wang, Yanli; Zhang, Dachuan; Bryant, Stephen H.
2011-01-01
Close to 60% of protein sequences tracked in comprehensive databases can be mapped to a known three-dimensional (3D) structure by standard sequence similarity searches. Potentially, a great deal can be learned about proteins or protein families of interest from considering 3D structure, and to this day 3D structure data may remain an underutilized resource. Here we present enhancements in the Molecular Modeling Database (MMDB) and its data presentation, specifically pertaining to biologically...
Compression of 3D models with NURBS
Santa Cruz Ducci, Diego; Ebrahimi, Touradj
2005-01-01
With recent progress in computing, algorithmics and telecommunications, 3D models are increasingly used in various multimedia applications. Examples include visualization, gaming, entertainment and virtual reality. In the multimedia domain 3D models have been traditionally represented as polygonal meshes. This piecewise planar representation can be thought of as the analogy of bitmap images for 3D surfaces. As bitmap images, they enjoy great flexibility and are particularly well suited to des...
A 3D Finite Element Method for Flexible Multibody Systems
An efficient finite element (FE) formulation for the simulation of multibody systems is derived from Hamilton's principle. According to the classical assumptions of multibody systems, a large rotation formulation has been chosen, where large rotations and large displacements, but only small deformations of the single bodies are taken into account. The strain tensor is linearized with respect to a co-rotated frame. The present approach uses absolute coordinates for the degrees of freedom and forms an alternative to the floating frame of reference formulation that is based on relative coordinates and describes deformation with respect to a co-rotated frame. Due to the modified strain tensor, the present formulation distinguishes significantly from standard nodal based nonlinear FE methods. Constraints are defined in integral form for every pair of surfaces of two bodies. This leads to a small number of constraint equations and avoids artificial stress singularities. The resulting mass and stiffness matrices are constant apart from a transformation based on a single rotation matrix for each body. The particular structure of this transformation allows to prevent from the usually expensive factorization of the system Jacobian within implicit time--integration methods. The present method has been implemented and tested with the FE-package NGSolve and specific 3D examples are verified with a standard beam formulation
Volume-Rendering-Based Interactive 3D Measurement for Quantitative Analysis of 3D Medical Images
Yakang Dai; Jian Zheng; Yuetao Yang; Duojie Kuai; Xiaodong Yang
2013-01-01
3D medical images are widely used to assist diagnosis and surgical planning in clinical applications, where quantitative measurement of interesting objects in the image is of great importance. Volume rendering is widely used for qualitative visualization of 3D medical images. In this paper, we introduce a volume-rendering-based interactive 3D measurement framework for quantitative analysis of 3D medical images. In the framework, 3D widgets and volume clipping are integrated with volume render...
3D Printing Making the Digital Real .
Miss Prachi More
2013-01-01
3D printing is quickly expanding field, with the popularity and uses for 3D printers growing every day. 3D printing can be used to prototype, create replacement parts, and is even versatile enough to print prostheses and medical implants. It will have a growing impact on our world, as more and more people gain access to these amazing machines.[1] In this article, we would like to attempt to give an introduction of the technology. 3Dimensions printing is a method of converting a virtual 3D mod...
3D-tulostuksen viipalointiohjelmien vertailu
Virolainen, Ville
2015-01-01
Opinnäytetyön tavoitteena on selventää 3D-tulostamisen prosessia yksityisen käyttäjän näkökulmasta sekä luoda testitulostuksia, joiden perusteella pystytään vertailemaan prosessissa käytettävien viipalointiohjelmien toimintaa keskenään. Työssä perehdytään aluksi 3D-tulostuksen teoriataustaan, jonka jälkeen suoritetaan 3D-tulostimella testitulostukset käyttäen kolmea eri viipalointiohjelmaa. 3D-tulostamisella tarkoitetaan prosessia, jonka tarkoituksena on luoda kolmiulotteinen objekti käyt...
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...
Myllykoski, Joonas; Palonen, Teemu
2015-01-01
Tämän opinnäytetyön tavoitteena oli selvittää miten Tekla Structures ohjelmalla luotu 3D-malli saadaan tulostettua koulun 3D-tulostimella sekä tutkittiin voidaanko Tekla Structuresin ominaisuuksia hyödyntää 3D-tulostamisessa ja miten tulostus onnistuu autocadilla. Selvitimme myös mahdollisia 3D-tulostusteknologian sovelluksia tulevaisuuden rakennustuotannossa ja sen näkymiä rakennusteollisuudessa sekä erilaisia tulostus menetelmiä joita voitaisiin mahdollisesti hyödyntää rakennusteollisuudess...
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...
Interaktiivinen 3D HTML5-selaimissa
Aaltonen, Jani
2013-01-01
Insinöörityön tavoitteena oli tutkia Metropolia Ammattikorkeakoulun mahdollisuuksia tuottaa interaktiivista 3D:tä verkkoselaimiin WebGL:n avulla ja käyttäen ammattikorkeakoulun 3D-mallinnusohjelmaa. WebGL on ohjelmointirajapinta, jolla saadaan luotua 3D-grafiikkaa verkkoselaimeen ilman ylimääräisiä liitännäisiä. Insinöörityö tehtiin Metropolia Ammattikorkeakoululle, ja sen tuloksia käytetään sekä osana opetusta että mahdollisesti 3D-sisällön tuottamiseen ammattikorkeakoulua varten. Työssä...
Calibration for 3D Structured Light Measurement
无
2007-01-01
A calibration procedure was developed for three-dimensional(3D) binocular structured light measurement systems. In virtue of a specially designed pattern, matching points in stereo images are extracted. And then sufficient 3D space points are obtained through pairs of images with the intrinsic and extrinsic parameters of each camera estimated prior and consequently some lights are calibrated by means of multi point fitting. Finally, a mathematical model is applied to interpolate and approximate all dynamic scanning lights based on geometry. The process of calibration method is successfully used in the binocular 3D measurement system based on structured lights and the 3D reconstruction results are satisfying.
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
Can 3D Printing change your business?
Unver, Ertu
2013-01-01
This presentation is given to businesses / companies with an interest in 3D Printing and Additive Manufacturing in West Yorkshire, UK Organised by the Calderdale and Kirklees Manufacturing Alliance. http://www.ckma.co.uk/ by Dr Ertu Unver Senior Lecturer / Product Design / MA 3D Digital Design / University of Huddersfield Location : 3M BIC, Date : 11th April, Time : 5.30 – 8pm Additive manufacturing or 3D printing is a process of making a three-dimensional (3D) objects from...
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.
3D modelling for multipurpose cadastre
Abduhl Rahman, A.; P. J. M. Van Oosterom; T. C. Hua; Sharkawi, K.H.; E. E. Duncan; 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 cadastre since more and more related agencies attempt to develop or embed 3D components into the MPC. We also intend to describe the initiative by Malaysian national mapping and cadastral agency (...
FastScript3D - A Companion to Java 3D
Koenig, Patti
2005-01-01
FastScript3D is a computer program, written in the Java 3D(TM) programming language, that establishes an alternative language that helps users who lack expertise in Java 3D to use Java 3D for constructing three-dimensional (3D)-appearing graphics. The FastScript3D language provides a set of simple, intuitive, one-line text-string commands for creating, controlling, and animating 3D models. The first word in a string is the name of a command; the rest of the string contains the data arguments for the command. The commands can also be used as an aid to learning Java 3D. Developers can extend the language by adding custom text-string commands. The commands can define new 3D objects or load representations of 3D objects from files in formats compatible with such other software systems as X3D. The text strings can be easily integrated into other languages. FastScript3D facilitates communication between scripting languages [which enable programming of hyper-text markup language (HTML) documents to interact with users] and Java 3D. The FastScript3D language can be extended and customized on both the scripting side and the Java 3D side.
SKB is planning to perform a large-scale pillar stability experiment called APSE (Aespoe Pillar Stability Experiment) at Aespoe HRL. The study is focused on understanding and control of progressive rock failure in hard crystalline rock and damage caused by high stresses. The elastic thermo-mechanical modeling was carried out in three dimensions because of the complex test geometry and in-situ stress tensor by using a finite-difference modeling software FLAC3D. Cracking and damage formation were modeled in the area of interest (pillar between two large scale holes) in two dimensions by using the Particle Flow Code (PFC), which is based on particle mechanics. FLAC and PFC were coupled to minimize the computer resources and the computing time. According to the modeling the initial temperature rises from 15 deg C to about 65 deg C in the pillar area during the heating period of 120 days. The rising temperature due to thermal expansion induces stresses in the pillar area and after 120 days heating the stresses have increased about 33% from the excavation induced maximum stress of 150 MPa to 200 MPa in the end of the heating period. The results from FLAC3D model showed that only regions where the crack initiation stress has exceeded were identified and they extended to about two meters down the hole wall. These could be considered the areas where damage may occur during the in-situ test. When the other hole is pressurized with a 0.8 MPa confining pressure it yields that 5 MPa more stress is needed to damage the rock than without confining pressure. This makes the damaged area in some degree smaller. High compressive stresses in addition to some tensile stresses might induce some AE (acoustic emission) activity in the upper part of the hole from the very beginning of the test and are thus potential areas where AE activities may be detected. Monitoring like acoustic emissions will be measured during the test execution. The 2D coupled PFC-FLAC modeling indicated that
3D PDF - a means of public access to geological 3D - objects, using the example of GTA3D
Slaby, Mark-Fabian; Reimann, Rüdiger
2013-04-01
In geology, 3D modeling has become very important. In the past, two-dimensional data such as isolines, drilling profiles, or cross-sections based on those, were used to illustrate the subsurface geology, whereas now, we can create complex digital 3D models. These models are produced with special software, such as GOCAD ®. The models can be viewed, only through the software used to create them, or through viewers available for free. The platform-independent PDF (Portable Document Format), enforced by Adobe, has found a wide distribution. This format has constantly evolved over time. Meanwhile, it is possible to display CAD data in an Adobe 3D PDF file with the free Adobe Reader (version 7). In a 3D PDF, a 3D model is freely rotatable and can be assembled from a plurality of objects, which can thus be viewed from all directions on their own. In addition, it is possible to create moveable cross-sections (profiles), and to assign transparency to the objects. Based on industry-standard CAD software, 3D PDFs can be generated from a large number of formats, or even be exported directly from this software. In geoinformatics, different approaches to creating 3D PDFs exist. The intent of the Authority for Mining, Energy and Geology to allow free access to the models of the Geotectonic Atlas (GTA3D), could not be realized with standard software solutions. A specially designed code converts the 3D objects to VRML (Virtual Reality Modeling Language). VRML is one of the few formats that allow using image files (maps) as textures, and to represent colors and shapes correctly. The files were merged in Acrobat X Pro, and a 3D PDF was generated subsequently. A topographic map, a display of geographic directions and horizontal and vertical scales help to facilitate the use.
Fogtmann, Mads; Seshamani, Sharmishtaa; Kroenke, Christopher; Cheng, Xi; Chapman, Teresa; Wilm, Jakob; Rousseau, François; Studholme, Colin
2013-01-01
This paper presents an approach to 3-D diffusion tensor image (DTI) reconstruction from multi-slice diffusion weighted (DW) magnetic resonance imaging acquisitions of the moving fetal brain. Motion scatters the slice measurements in the spatial and spherical diffusion domain with respect to the underlying anatomy. Previous image registration techniques have been described to estimate the between slice fetal head motion, allowing the reconstruction of 3-D a diffusion estimate on a regular grid...
Solid friction at high sliding velocities: an explicit 3D dynamical SPH approach
Maveyraud, C.; Benz, W.; Ouillon, G.; Sornette, A.; Sornette, D.
1998-01-01
We present realistic 3D numerical simulations of elastic bodies sliding on top of each other in a regime of velocities ranging from meters to tens of meters per second using the so-called Smoothed Particle Hydrodynamics (SPH) method. Our investigations are restricted to regimes of pressure and roughness where only elastic deformations occur between asperities at the contact surface between the slider block and the substrate. In this regime, solid friction is due to the generation of vibration...
An aerial 3D printing test mission
Hirsch, Michael; McGuire, Thomas; Parsons, Michael; Leake, Skye; Straub, Jeremy
2016-05-01
This paper provides an overview of an aerial 3D printing technology, its development and its testing. This technology is potentially useful in its own right. In addition, this work advances the development of a related in-space 3D printing technology. A series of aerial 3D printing test missions, used to test the aerial printing technology, are discussed. Through completing these test missions, the design for an in-space 3D printer may be advanced. The current design for the in-space 3D printer involves focusing thermal energy to heat an extrusion head and allow for the extrusion of molten print material. Plastics can be used as well as composites including metal, allowing for the extrusion of conductive material. A variety of experiments will be used to test this initial 3D printer design. High altitude balloons will be used to test the effects of microgravity on 3D printing, as well as parabolic flight tests. Zero pressure balloons can be used to test the effect of long 3D printing missions subjected to low temperatures. Vacuum chambers will be used to test 3D printing in a vacuum environment. The results will be used to adapt a current prototype of an in-space 3D printer. Then, a small scale prototype can be sent into low-Earth orbit as a 3-U cube satellite. With the ability to 3D print in space demonstrated, future missions can launch production hardware through which the sustainability and durability of structures in space will be greatly improved.
3D ultrafast ultrasound imaging in vivo
Very high frame rate ultrasound imaging has recently allowed for the extension of the applications of echography to new fields of study such as the functional imaging of the brain, cardiac electrophysiology, and the quantitative imaging of the intrinsic mechanical properties of tumors, to name a few, non-invasively and in real time. In this study, we present the first implementation of Ultrafast Ultrasound Imaging in 3D based on the use of either diverging or plane waves emanating from a sparse virtual array located behind the probe. It achieves high contrast and resolution while maintaining imaging rates of thousands of volumes per second. A customized portable ultrasound system was developed to sample 1024 independent channels and to drive a 32 × 32 matrix-array probe. Its ability to track in 3D transient phenomena occurring in the millisecond range within a single ultrafast acquisition was demonstrated for 3D Shear-Wave Imaging, 3D Ultrafast Doppler Imaging, and, finally, 3D Ultrafast combined Tissue and Flow Doppler Imaging. The propagation of shear waves was tracked in a phantom and used to characterize its stiffness. 3D Ultrafast Doppler was used to obtain 3D maps of Pulsed Doppler, Color Doppler, and Power Doppler quantities in a single acquisition and revealed, at thousands of volumes per second, the complex 3D flow patterns occurring in the ventricles of the human heart during an entire cardiac cycle, as well as the 3D in vivo interaction of blood flow and wall motion during the pulse wave in the carotid at the bifurcation. This study demonstrates the potential of 3D Ultrafast Ultrasound Imaging for the 3D mapping of stiffness, tissue motion, and flow in humans in vivo and promises new clinical applications of ultrasound with reduced intra—and inter-observer variability. (fast track communication)
Maharramov, Musa
2013-01-01
This paper has evolved out of our previous work on static stress transfer, where we used the full-space elastostatic Green's tensor to compute the Coulomb stress transfer impact of the Landers earthquake on the Hector Mine event. In this work, we use the elastostatic Green's tensor for an arbitrary layered Earth model with free-surface boundary conditions to study the impact of elastic heterogeneity as well as source-fault slip and geometry on the stress transfer mechanism. Slip distribution and fault geometry of the source have a significant impact on the stress transfer, especially in case of spatially extended triggered events. Maximization of the Coulomb stress transfer function for known aftershocks provides a mechanism for inverting for the source event slip. Heterogeneity of the elastic earth parameters is shown to have a sizeable, but lower-magnitude, impact on the static stress transfer in 3D. The analysis is applied to Landers/Hector Mine and 100 small "aftershocks" of the Landers event. A computati...
Superintegrable potentials on 3D Riemannian and Lorentzian spaces with non-constant curvature
Ballesteros, Angel; Enciso, Alberto; Herranz, Francisco J.; Ragnisco, Orlando
2008-01-01
A quantum sl(2,R) coalgebra is shown to underly the construction of a large class of superintegrable potentials on 3D curved spaces, that include the non-constant curvature analogues of the spherical, hyperbolic and (anti-)de Sitter spaces. The connection and curvature tensors for these "deformed" spaces are fully studied by working on two different phase spaces. The former directly comes from a 3D symplectic realization of the deformed coalgebra, while the latter is obtained through a map le...
3D Motion Estimation and Motion Fusion by Affine Region Matching
魏国庆; 马颂德
1993-01-01
In this paper,a new method is presented for 3D motion estimation by image region correspondences using stereo cameras.Under the weak perspectivity assumption.we first employ the moment tensor theory (Cyganski and Orr[11]) to compute the monocular affine transformations relating images taken by the same camera at different time instants and the binocular affine transformations relating images taken by different cameras at the same time instant.We then show that 3D motion can be recovered from these 2D transformations.A space-time fusion strategy is proposed to aim at robust results.No knowledge of point correspondences if requred in the above processes and the computations involved are linear.To find corresponding image regions,new affine invariants,which show stronger invariance,are derived in term of tensor contraction theory.Experiments on real motion images are conducted to verify the proposed method.
Tensor numerical methods in quantum chemistry: from Hartree-Fock to excitation energies.
Khoromskaia, Venera; Khoromskij, Boris N
2015-12-21
We resume the recent successes of the grid-based tensor numerical methods and discuss their prospects in real-space electronic structure calculations. These methods, based on the low-rank representation of the multidimensional functions and integral operators, first appeared as an accurate tensor calculus for the 3D Hartree potential using 1D complexity operations, and have evolved to entirely grid-based tensor-structured 3D Hartree-Fock eigenvalue solver. It benefits from tensor calculation of the core Hamiltonian and two-electron integrals (TEI) in O(n log n) complexity using the rank-structured approximation of basis functions, electron densities and convolution integral operators all represented on 3D n × n × n Cartesian grids. The algorithm for calculating TEI tensor in a form of the Cholesky decomposition is based on multiple factorizations using algebraic 1D "density fitting" scheme, which yield an almost irreducible number of product basis functions involved in the 3D convolution integrals, depending on a threshold ε > 0. The basis functions are not restricted to separable Gaussians, since the analytical integration is substituted by high-precision tensor-structured numerical quadratures. The tensor approaches to post-Hartree-Fock calculations for the MP2 energy correction and for the Bethe-Salpeter excitation energies, based on using low-rank factorizations and the reduced basis method, were recently introduced. Another direction is towards the tensor-based Hartree-Fock numerical scheme for finite lattices, where one of the numerical challenges is the summation of electrostatic potentials of a large number of nuclei. The 3D grid-based tensor method for calculation of a potential sum on a L × L × L lattice manifests the linear in L computational work, O(L), instead of the usual O(L(3) log L) scaling by the Ewald-type approaches. PMID:26016539
3-D structures of planetary nebulae
Steffen, Wolfgang
2016-01-01
Recent advances in the 3-D reconstruction of planetary nebulae are reviewed. We include not only results for 3-D reconstructions, but also the current techniques in terms of general methods and software. In order to obtain more accurate reconstructions, we suggest to extend the widely used assumption of homologous nebula expansion to map spectroscopically measured velocity to position along the line of sight.
3D printing of functional structures
Krijnen, G.J.M.
2016-01-01
The technology colloquial known as ‘3D printing’ has developed in such diversity in printing technologies and application fields that meanwhile it seems anything is possible. However, clearly the ideal 3D Printer, with high resolution, multi-material capability, fast printing, etc. is yet to be deve
3D Printed Block Copolymer Nanostructures
Scalfani, Vincent F.; Turner, C. Heath; Rupar, Paul A.; Jenkins, Alexander H.; Bara, Jason E.
2015-01-01
The emergence of 3D printing has dramatically advanced the availability of tangible molecular and extended solid models. Interestingly, there are few nanostructure models available both commercially and through other do-it-yourself approaches such as 3D printing. This is unfortunate given the importance of nanotechnology in science today. In this…
Perception of detail in 3D images
Heyndrickx, I.; Kaptein, R.
2009-01-01
A lot of current 3D displays suffer from the fact that their spatial resolution is lower compared to their 2D counterparts. One reason for this is that the multiple views needed to generate 3D are often spatially multiplexed. Besides this, imperfect separation of the left- and right-eye view leads t
3D Reconstruction of NMR Images
Peter Izak; Milan Smetana; Libor Hargas; Miroslav Hrianka; Pavol Spanik
2007-01-01
This paper introduces experiment of 3D reconstruction NMR images scanned from magnetic resonance device. There are described methods which can be used for 3D reconstruction magnetic resonance images in biomedical application. The main idea is based on marching cubes algorithm. For this task was chosen sophistication method by program Vision Assistant, which is a part of program LabVIEW.
Stereo 3-D Vision in Teaching Physics
Zabunov, Svetoslav
2012-01-01
Stereo 3-D vision is a technology used to present images on a flat surface (screen, paper, etc.) and at the same time to create the notion of three-dimensional spatial perception of the viewed scene. A great number of physical processes are much better understood when viewed in stereo 3-D vision compared to standard flat 2-D presentation. The…
Norbury, Keith
2012-01-01
It may be too soon for students to be showing up for class with popcorn and gummy bears, but technology similar to that behind the 3D blockbuster movie "Avatar" is slowly finding its way into college classrooms. 3D classroom projectors are taking students on fantastic voyages inside the human body, to the ruins of ancient Greece--even to faraway…
Holmgren, Steen; Rüdiger, Bjarne; Tournay, Bruno
2001-01-01
We have worked with the construction and use of 3D city models for about ten years. This work has given us valuable experience concerning model methodology. In addition to this collection of knowledge, our perception of the concept of city models has changed radically. In order to explain...... of 3D city models....
Immersive 3D Geovisualization in Higher Education
Philips, Andrea; Walz, Ariane; Bergner, Andreas; Graeff, Thomas; Heistermann, Maik; Kienzler, Sarah; Korup, Oliver; Lipp, Torsten; Schwanghart, Wolfgang; Zeilinger, Gerold
2015-01-01
In this study, we investigate how immersive 3D geovisualization can be used in higher education. Based on MacEachren and Kraak's geovisualization cube, we examine the usage of immersive 3D geovisualization and its usefulness in a research-based learning module on flood risk, called GEOSimulator. Results of a survey among participating students…
Parametrizable cameras for 3D computational steering
Mulder, J.D.; Wijk, J.J. van
1997-01-01
We present a method for the definition of multiple views in 3D interfaces for computational steering. The method uses the concept of a point-based parametrizable camera object. This concept enables a user to create and configure multiple views on his custom 3D interface in an intuitive graphical man
Wow! 3D Content Awakens the Classroom
Gordon, Dan
2010-01-01
From her first encounter with stereoscopic 3D technology designed for classroom instruction, Megan Timme, principal at Hamilton Park Pacesetter Magnet School in Dallas, sensed it could be transformative. Last spring, when she began pilot-testing 3D content in her third-, fourth- and fifth-grade classrooms, Timme wasn't disappointed. Students…
3D background aerodynamics using CFD
Sørensen, Niels N.
2002-01-01
3D rotor computations for the Greek Geovilogiki (GEO) 44 meter rotor equipped with 19 meters blades are performed. The lift and drag polars are extracted at five spanvise locations r/R= (.37, .55, .71, .82, .93) based on identification of stagnationpoints between 2D and 3D computations. The inner...
3D directional coupler for impulse UWB
Le Kernec, Julien; KLEPAL, Martin; Sokol, Vratislav
2011-01-01
The AWS Group developed a UWB radar and UWB transceiver for indoor people location and tracking. A radar concept has been developed. This paper will describe step by step the realization of a UWB directional coupler with a novel 3-D architecture. This paper gives a walkthrough of our design of the 3-D directional coupler.
Limited Feedback for 3D Massive MIMO under 3D-UMa and 3D-UMi Scenarios
Zheng Hu
2015-01-01
Full Text Available For three-dimensional (3D massive MIMO utilizing the uniform rectangular array (URA in the base station (BS, we propose a limited feedback transmission scheme in which the channel state information (CSI feedback operations for horizontal domain and vertical domain are separate. Compared to the traditional feedback scheme, the scheme can reduce the feedback overhead, code word index search complexity, and storage requirement. Also, based on the zenith of departure angle (ZoD distribution in 3D-Urban Macro Cell (3D-UMa and 3D-Urban Micro Cell (3D-UMi scenarios, we propose the angle quantization codebook for vertical domain, while the codebook of long term evolution-advanced (LTE-Advanced is still adopted in horizontal domain to preserve compatibility with the LTE-Advanced. Based on the angle quantization codebook, the subsampled 3-bit DFT codebook is designed for vertical domain. The system-level simulation results reveal that, to compromise the feedback overhead and system performance, 2-bit codebook for 3D-UMa scenario and 3-bit codebook for 3D-UMi scenario can meet requirements in vertical domain. The feedback period for vertical domain can also be extended appropriately to reduce the feedback overhead.
Terajets produced by 3D dielectric cuboids
Pacheco-Peña, V; Minin, I V; Minin, O V
2014-01-01
The capability of generating terajets using 3D dielectric cuboids working at terahertz (THz) frequencies (as analogues of nanojets in the infrared band) are introduced and studied numerically. The focusing performance of the terajets are evaluated in terms of the transversal full width at half maximum along x- and y- directions using different refractive indexes for a 3D dielectric cuboid with a fixed geometry, obtaining a quasi-symmetric terajet with a subwavelength resolution of ~0.46{\\lambda}0 when the refractive index is n = 1.41. Moreover, the backscattering enhancement produced when metal particles are introduced in the terajet region is demonstrated for a 3D dielectric cuboid and compared with its 2D counterpart. The results of the jet generated for the 3D case are experimentally validated at sub-THz waves, demonstrating the ability to produce terajets using 3D cuboids.
Fabrication of 3D Silicon Sensors
Kok, A.; Hansen, T.E.; Hansen, T.A.; Lietaer, N.; Summanwar, A.; /SINTEF, Oslo; Kenney, C.; Hasi, J.; /SLAC; Da Via, C.; /Manchester U.; Parker, S.I.; /Hawaii U.
2012-06-06
Silicon sensors with a three-dimensional (3-D) architecture, in which the n and p electrodes penetrate through the entire substrate, have many advantages over planar silicon sensors including radiation hardness, fast time response, active edge and dual readout capabilities. The fabrication of 3D sensors is however rather complex. In recent years, there have been worldwide activities on 3D fabrication. SINTEF in collaboration with Stanford Nanofabrication Facility have successfully fabricated the original (single sided double column type) 3D detectors in two prototype runs and the third run is now on-going. This paper reports the status of this fabrication work and the resulted yield. The work of other groups such as the development of double sided 3D detectors is also briefly reported.
Sillanpää, Otto
2014-01-01
Tässä opinnäytetyössä tutkitaan miten 3D-mallit saadaan sellaiseen muotoon, että ne olisivat käytettävissä eri pelimoottoreissa. Tutkimuksen tarkoituksena on selvittää, miten luodaan 3D-malleja pelimoottoreihin, sekä miten 3D-mallinnusohjelmat ja pelimoottorit eroavat toisistaan, kun käsitellään 3D-malleja. Tässä työssä pelimoottoreina toimivat Valven Source sekä Epic Gamesin Unreal Engine 3. 3D-mallinnusohjelmista käytössä olivat Autodeskin 3ds Max 2014 ja Blender Foundationin Blender 2.7...
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
6D Interpretation of 3D Gravity
Herfray, Yannick; Scarinci, Carlos
2016-01-01
We show that 3D gravity, in its pure connection formulation, admits a natural 6D interpretation. The 3D field equations for the connection are equivalent to 6D Hitchin equations for the Chern-Simons 3-form in the total space of the principal bundle over the 3-dimensional base. Turning this construction around one gets an explanation of why the pure connection formulation of 3D gravity exists. More generally, we interpret 3D gravity as the dimensional reduction of the 6D Hitchin theory. To this end, we show that any SU(2) invariant closed 3-form in the total space of the principal SU(2) bundle can be parametrised by a connection together with a 2-form field on the base. The dimensional reduction of the 6D Hitchin theory then gives rise to 3D gravity coupled to a topological 2-form field.
Tensors, relativity, and cosmology
Dalarsson, Mirjana
2015-01-01
Tensors, Relativity, and Cosmology, Second Edition, combines relativity, astrophysics, and cosmology in a single volume, providing a simplified introduction to each subject that is followed by detailed mathematical derivations. The book includes a section on general relativity that gives the case for a curved space-time, presents the mathematical background (tensor calculus, Riemannian geometry), discusses the Einstein equation and its solutions (including black holes and Penrose processes), and considers the energy-momentum tensor for various solutions. In addition, a section on relativistic astrophysics discusses stellar contraction and collapse, neutron stars and their equations of state, black holes, and accretion onto collapsed objects, with a final section on cosmology discussing cosmological models, observational tests, and scenarios for the early universe. This fully revised and updated second edition includes new material on relativistic effects, such as the behavior of clocks and measuring rods in m...
Relativistic segnificance of curvature tensors
G. P. Pokhariyal
1982-01-01
Full Text Available In thi paper new curvature tensors have been defined on the lines of Weyl's projective curvature tensor and it has been shown that the distribution (order in which the vectors in question are arranged before being acted upon by the tensor in question of vector field over the metric potentials and matter tensors plays an important role in shaping the various physical and geometrical properties of a tensor viz the formulation of gravitational waves, reduction of electromagnetic field to a purely electric field, vanishing of the contracted tensor in an Einstein Space and the cyclic property.
The psychology of the 3D experience
Janicke, Sophie H.; Ellis, Andrew
2013-03-01
With 3D televisions expected to reach 50% home saturation as early as 2016, understanding the psychological mechanisms underlying the user response to 3D technology is critical for content providers, educators and academics. Unfortunately, research examining the effects of 3D technology has not kept pace with the technology's rapid adoption, resulting in large-scale use of a technology about which very little is actually known. Recognizing this need for new research, we conducted a series of studies measuring and comparing many of the variables and processes underlying both 2D and 3D media experiences. In our first study, we found narratives within primetime dramas had the power to shift viewer attitudes in both 2D and 3D settings. However, we found no difference in persuasive power between 2D and 3D content. We contend this lack of effect was the result of poor conversion quality and the unique demands of 3D production. In our second study, we found 3D technology significantly increased enjoyment when viewing sports content, yet offered no added enjoyment when viewing a movie trailer. The enhanced enjoyment of the sports content was shown to be the result of heightened emotional arousal and attention in the 3D condition. We believe the lack of effect found for the movie trailer may be genre-related. In our final study, we found 3D technology significantly enhanced enjoyment of two video games from different genres. The added enjoyment was found to be the result of an increased sense of presence.
3D Visualization Development of SIUE Campus
Nellutla, Shravya
Geographic Information Systems (GIS) has progressed from the traditional map-making to the modern technology where the information can be created, edited, managed and analyzed. Like any other models, maps are simplified representations of real world. Hence visualization plays an essential role in the applications of GIS. The use of sophisticated visualization tools and methods, especially three dimensional (3D) modeling, has been rising considerably due to the advancement of technology. There are currently many off-the-shelf technologies available in the market to build 3D GIS models. One of the objectives of this research was to examine the available ArcGIS and its extensions for 3D modeling and visualization and use them to depict a real world scenario. Furthermore, with the advent of the web, a platform for accessing and sharing spatial information on the Internet, it is possible to generate interactive online maps. Integrating Internet capacity with GIS functionality redefines the process of sharing and processing the spatial information. Enabling a 3D map online requires off-the-shelf GIS software, 3D model builders, web server, web applications and client server technologies. Such environments are either complicated or expensive because of the amount of hardware and software involved. Therefore, the second objective of this research was to investigate and develop simpler yet cost-effective 3D modeling approach that uses available ArcGIS suite products and the free 3D computer graphics software for designing 3D world scenes. Both ArcGIS Explorer and ArcGIS Online will be used to demonstrate the way of sharing and distributing 3D geographic information on the Internet. A case study of the development of 3D campus for the Southern Illinois University Edwardsville is demonstrated.
Killing tensors and conformal Killing tensors from conformal Killing vectors
Koutras has proposed some methods to construct reducible proper conformal Killing tensors and Killing tensors (which are, in general, irreducible) when a pair of orthogonal conformal Killing vectors exist in a given space. We give the completely general result demonstrating that this severe restriction of orthogonality is unnecessary. In addition, we correct and extend some results concerning Killing tensors constructed from a single conformal Killing vector. A number of examples demonstrate that it is possible to construct a much larger class of reducible proper conformal Killing tensors and Killing tensors than permitted by the Koutras algorithms. In particular, by showing that all conformal Killing tensors are reducible in conformally flat spaces, we have a method of constructing all conformal Killing tensors, and hence all the Killing tensors (which will in general be irreducible) of conformally flat spaces using their conformal Killing vectors
Physical components of tensors
Altman, Wolf
2014-01-01
""This book provides a clear explanation of the mathematical properties of tensors, from a physical perspective. The book is rigorous and concise, yet easy to read and very accessible. The reader will enjoy the wide variety of examples and exercises with solution, which make the book very pedagogical. I believe this can be a very useful book for anyone interested in learning about the mathematics of tensors, no matter the field of study or research. I would definitely like to have this book on my shelf, and use it as a reference in my own lectures."" -Román Orús, Institut für Physik, Jo
Phan, A. H.; Tichavský, Petr; Cichocki, A.
Piscataway: IEEE Computer Society, 2015, s. 2169-2173. ISBN 978-1-4673-6997-8. ISSN 1520-6149. [2015 IEEE International Conference on Acoustics, Speech, and Signal Processing ICASSP 2015. Brisbane (AU), 19.04.2015-24.04.2015] R&D Projects: GA ČR(CZ) GA14-13713S Institutional support: RVO:67985556 Keywords : tensor decomposition * CANDECOMP/PARAFAC * tensor deconvolution Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2015/SI/tichavsky-0443717.pdf
Use of 3-D modeling in the early development phase of pectin tablets
Linda Salbu
2012-03-01
Full Text Available This study examines the contribution of a 3-D model in an early development of pectin tablets. The aim of this work was to extract as much information of the compression behavior from as few tablets as possible. Pectins with various degrees of methoxylation (DM were studied (4%-72%. The compressibility was evaluated using classic “in-die” Heckel and Kawakita analyses in addition to the 3-D modeling. For validation purposes well-known reference materials were included. 3-D modeling applied to data of single tablets yielded some information on their compressibility. When several tablets with different maximum relative densities (p rel, max were included, no additional information was obtained through classic evaluation. However, the 3-Dmodel provided additional information through the shape of the 3-D parameter plot. Pectins with a DM $ 25% consolidated predominantly by elastic deformation similarly to the 3-D parameter plot ofpregelatinized starch (PGS. The 3-D analysis also suggests some degree of fragmentation and, for some of the low-methoxylated pectins (DM <= 10%, viscoelastic deformation. This study showed that by applying 3-D modeling it is possible to differentiate between elastic and viscoelastic materials for tablets with different p rel,max values.
Hu Ying-Cai; Li Tong-Lin; Fan Cui-Song; Wang Da-Yong; Li Jian-Ping
2015-01-01
Scalar CSAMT is only suitable for measurements in one and two dimensions perpendicular to geological structures. For complex 3D geoelectric structure, tensor CSAMT is more suitable. In this paper, we discuss 3D tensor CSAMT forward modeling using the vector finite-element method. To verify the feasibility of the algorithm, we calculate the electric field, magnetic field, and tensor impedance of the 3D CSAMT far-zone field in layered media and compare them with theoretical solutions. In addition, a three-dimensional anomaly in half-space is also simulated, and the response characteristics of the impedance tensor and the apparent resistivity and impedance phase are analyzed. The results suggest that the vector finite-element method produces high-precision electromagnetic field and impedance tensor data, satisfies the electric field discontinuity, and does not require divergence correction using the vectorfi nite-element method.
Fundamental study on REV based on crack tensor at the Mizunami Underground Research Laboratory
The crack tensor model which is a kind of equivalent continuum model has been studied in rock mechanical investigation in the MIU. The fractured rock mass is modeled as the elastic continuum model with this crack tensor. In this study, this crack tensor based on the geological observation in the MIU project was calculated, and Representative Elementary Volume (REV) in the ventilation shaft and -300 m access/research gallery was studied based on the relative error of this crack tensor. As a result, the convergence of the relative error was faster in the -300 m access/research gallery than in the ventilation shaft. (author)
Semi- and virtual 3D dosimetry in clinical practice
Korreman, S. S.
2013-01-01
In this review, 3D dosimetry is divided in three categories; "true" 3D, semi-3D and virtual 3D. Virtual 3D involves the use of measurement arrays either before or after beam entry in the patient/phantom, whereas semi-3D involves use of measurement arrays in phantoms mimicking the patient. True 3D...
3D object-oriented image analysis in 3D geophysical modelling
Fadel, I.; van der Meijde, M.; Kerle, N.;
2015-01-01
Non-uniqueness of satellite gravity interpretation has traditionally been reduced by using a priori information from seismic tomography models. This reduction in the non-uniqueness has been based on velocity-density conversion formulas or user interpretation of the 3D subsurface structures (objects......) based on the seismic tomography models and then forward modelling these objects. However, this form of object-based approach has been done without a standardized methodology on how to extract the subsurface structures from the 3D models. In this research, a 3D object-oriented image analysis (3D OOA......) approach was implemented to extract the 3D subsurface structures from geophysical data. The approach was applied on a 3D shear wave seismic tomography model of the central part of the East African Rift System. Subsequently, the extracted 3D objects from the tomography model were reconstructed in the 3D...
3D Reconstruction Technique for Tomographic PIV
姜楠; 包全; 杨绍琼
2015-01-01
Tomographic particle image velocimetry(Tomo-PIV) is a state-of-the-art experimental technique based on a method of optical tomography to achieve the three-dimensional(3D) reconstruction for three-dimensional three-component(3D-3C) flow velocity measurements. 3D reconstruction for Tomo-PIV is carried out herein. Meanwhile, a 3D simplified tomographic reconstruction model reduced from a 3D volume light inten-sity field with 2D projection images into a 2D Tomo-slice plane with 1D projecting lines, i.e., simplifying this 3D reconstruction into a problem of 2D Tomo-slice plane reconstruction, is applied thereafter. Two kinds of the most well-known algebraic reconstruction techniques, algebraic reconstruction technique(ART) and multiple algebraic reconstruction technique(MART), are compared as well. The principles of the two reconstruction algorithms are discussed in detail, which has been performed by a series of simulation images, yielding the corresponding recon-struction images that show different features between the ART and MART algorithm, and then their advantages and disadvantages are discussed. Further discussions are made for the standard particle image reconstruction when the background noise of the pre-initial particle image has been removed. Results show that the particle image recon-struction has been greatly improved. The MART algorithm is much better than the ART. Furthermore, the computa-tional analyses of two parameters(the particle density and the number of cameras), are performed to study their effects on the reconstruction. Lastly, the 3D volume particle field is reconstructed by using the improved algorithm based on the simplified 3D tomographic reconstruction model, which proves that the algorithm simplification is feasible and it can be applied to the reconstruction of 3D volume particle field in a Tomo-PIV system.
Extra Dimensions: 3D in PDF Documentation
Experimental science is replete with multi-dimensional information which is often poorly represented by the two dimensions of presentation slides and print media. Past efforts to disseminate such information to a wider audience have failed for a number of reasons, including a lack of standards which are easy to implement and have broad support. Adobe's Portable Document Format (PDF) has in recent years become the de facto standard for secure, dependable electronic information exchange. It has done so by creating an open format, providing support for multiple platforms and being reliable and extensible. By providing support for the ECMA standard Universal 3D (U3D) and the ISO PRC file format in its free Adobe Reader software, Adobe has made it easy to distribute and interact with 3D content. Until recently, Adobe's Acrobat software was also capable of incorporating 3D content into PDF files from a variety of 3D file formats, including proprietary CAD formats. However, this functionality is no longer available in Acrobat X, having been spun off to a separate company. Incorporating 3D content now requires the additional purchase of a separate plug-in. In this talk we present alternatives based on open source libraries which allow the programmatic creation of 3D content in PDF format. While not providing the same level of access to CAD files as the commercial software, it does provide physicists with an alternative path to incorporate 3D content into PDF files from such disparate applications as detector geometries from Geant4, 3D data sets, mathematical surfaces or tesselated volumes.
Adaptive Multilinear Tensor Product Wavelets.
Weiss, Kenneth; Lindstrom, Peter
2016-01-01
Many foundational visualization techniques including isosurfacing, direct volume rendering and texture mapping rely on piecewise multilinear interpolation over the cells of a mesh. However, there has not been much focus within the visualization community on techniques that efficiently generate and encode globally continuous functions defined by the union of multilinear cells. Wavelets provide a rich context for analyzing and processing complicated datasets. In this paper, we exploit adaptive regular refinement as a means of representing and evaluating functions described by a subset of their nonzero wavelet coefficients. We analyze the dependencies involved in the wavelet transform and describe how to generate and represent the coarsest adaptive mesh with nodal function values such that the inverse wavelet transform is exactly reproduced via simple interpolation (subdivision) over the mesh elements. This allows for an adaptive, sparse representation of the function with on-demand evaluation at any point in the domain. We focus on the popular wavelets formed by tensor products of linear B-splines, resulting in an adaptive, nonconforming but crack-free quadtree (2D) or octree (3D) mesh that allows reproducing globally continuous functions via multilinear interpolation over its cells. PMID:26529742
Tensor Metrics and Charged Containers for 3D Q-space Sample Distribution
Knutsson, Hans; Westin, Carl-Fredrik
2013-01-01
This paper extends Jones’ popular electrostatic repulsion based algorithm for distribution of single-shell Q-space samples in two fundamental ways. The first alleviates the single-shell requirement enabling full Q-space sampling. Such an extension is not immediately obvious since it requires distributing samples evenly in 3 dimensions. The extension is as elegant as it is simple: Add a container volume of the desired shape having a constant charge density and a total charge equal to the negat...
An Improved Version of TOPAZ 3D
Krasnykh, Anatoly K
2003-01-01
An improved version of the TOPAZ 3D gun code is presented as a powerful tool for beam optics simulation. In contrast to the previous version of TOPAZ 3D, the geometry of the device under test is introduced into TOPAZ 3D directly from a CAD program, such as Solid Edge or AutoCAD. In order to have this new feature, an interface was developed, using the GiD software package as a meshing code. The article describes this method with two models to illustrate the results.
Matching Feature Points in 3D World
Avdiu, Blerta
2012-01-01
This thesis work deals with the most actual topic in Computer Vision field which is scene understanding and this using matching of 3D feature point images. The objective is to make use of Saab’s latest breakthrough in extraction of 3D feature points, to identify the best alignment of at least two 3D feature point images. The thesis gives a theoretical overview of the latest algorithms used for feature detection, description and matching. The work continues with a brief description of the simu...
3-D Human Modeling and Animation
Ratner, Peter
2012-01-01
3-D Human Modeling and Animation Third Edition All the tools and techniques you need to bring human figures to 3-D life Thanks to today's remarkable technology, artists can create and animate realistic, three-dimensional human figures that were not possible just a few years ago. This easy-to-follow book guides you through all the necessary steps to adapt your own artistic skill in figure drawing, painting, and sculpture to this exciting digital canvas. 3-D Human Modeling and Animation, Third Edition starts you off with simple modeling, then prepares you for more advanced techniques for crea
Zhang, Peter; Millos, Evangelous; Gu, Jason
2009-01-01
This chapter established an approach to solve the full 3D SLAM problem, applied to an underwater environment. First, a general approach to the 3D SLAM problem was presented, which included the models in 3D case, data association and estimation algorithm. For an underwater mobile robot, a new measurement system was designed for large area's globally-consistent SLAM: buoys for long-range estimation, and camera for short-range estimation and map building. Globally-consistent results could be obt...
Biedron, Robert T.; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, William L.; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; Rumsey, Christopher L.; Thomas, James L.; Wood, William A.
2014-01-01
This manual describes the installation and execution of FUN3D version 12.5, including optional dependent packages. FUN3D is a suite of computational uid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables ecient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.
Biedron, Robert T.; Carlson, Jan-Renee; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bill; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; Rumsey, Christopher L.; Thomas, James L.; Wood, William A.
2016-01-01
This manual describes the installation and execution of FUN3D version 13.0, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.
Biedron, Robert T.; Carlson, Jan-Renee; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bil; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; Rumsey, Christopher L.; Thomas, James L.; Wood, William A.
2016-01-01
This manual describes the installation and execution of FUN3D version 12.9, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.
Biedron, Robert T.; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bil; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; Rumsey, Christopher L.; Thomas, James L.; Wood, William A.
2014-01-01
This manual describes the installation and execution of FUN3D version 12.4, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixedelement unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.
Spagnuolo, Michela; Falcidieno, Bianca
2009-01-01
3D content is widely recognized as the next wave of digital media. The success of 3D communities and mapping applications (for example, Second Life and GoogleEarth) and the decreasing costs of producing 3D environments are leading analysts to predict a dramatic shift in how people see and navigate the Internet. Greg Sterling, founder of the research fi rm Sterling Market Intelligence, suggests that"the Internet could very well be on its way to shifting from a text-based environment to a visua...
Vataščinová, Lenka
2016-01-01
In my bachelor thesis, I am going to introduce the topic of 3D graphics in the game environment. Firstly, I will provide a brief introduction of history of 3D graphics in general, but with the emphasis on history of game industry in particular. Next, I will present 3D graphics of RPG games in particular, and I will analyse the graphical side of digital work production. The main contribution of this thesis is provided in the practical part, which deals with creation of an environment for an an...
An Improved Version of TOPAZ 3D
An improved version of the TOPAZ 3D gun code is presented as a powerful tool for beam optics simulation. In contrast to the previous version of TOPAZ 3D, the geometry of the device under test is introduced into TOPAZ 3D directly from a CAD program, such as Solid Edge or AutoCAD. In order to have this new feature, an interface was developed, using the GiD software package as a meshing code. The article describes this method with two models to illustrate the results
Robot Arms with 3D Vision Capabilities
Borangiu, Theodor; Alexandru DUMITRACHE
2010-01-01
This chapter presented two applications of 3D vision in industrial robotics. The first one allows 3D reconstruction of decorative objects using a laser-based profile scanner mounted on a 6-DOF industrial robot arm, while the scanned part is placed on a rotary table. The second application uses the same profile scanner for 3D robot guidance along a complex path, which is learned automatically using the laser sensor and then followed using a physical tool. While the laser sensor is an expensive...
Automatic balancing of 3D models
Christiansen, Asger Nyman; Schmidt, Ryan; Bærentzen, Jakob Andreas
2014-01-01
3D printing technologies allow for more diverse shapes than are possible with molds and the cost of making just one single object is negligible compared to traditional production methods. However, not all shapes are suitable for 3D print. One of the remaining costs is therefore human time spent......, in these cases, we will apply a rotation of the object which only deforms the shape a little near the base. No user input is required but it is possible to specify manufacturing constraints related to specific 3D print technologies. Several models have successfully been balanced and printed using both polyjet...
3D Printing the ATLAS' barrel toroid
Goncalves, Tiago Barreiro
2016-01-01
The present report summarizes my work as part of the Summer Student Programme 2016 in the CERN IR-ECO-TSP department (International Relations – Education, Communication & Outreach – Teacher and Student Programmes). Particularly, I worked closely with the S’Cool LAB team on a science education project. This project included the 3D designing, 3D printing, and assembling of a model of the ATLAS’ barrel toroid. A detailed description of the project' development is presented and a short manual on how to use 3D printing software and hardware is attached.
Participation and 3D Visualization Tools
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...
The reactor dynamics code DYN3D
The article provides an overview on the code DYN3D which is a three-dimensional core model for steady-state, dynamic and depletion calculations in reactor cores with quadratic or hexagonal fuel assembly geometry being developed by the Helmholtz-Zentrum Dresden-Rossendorf for more than 20 years. The current paper gives an overview on the basic DYN3D models and the available code couplings. The verification and validation status is shortly outlined. The paper concludes with the current developments of the DYN3D code. For more detailed information the reader is referred to the publications cited in the corresponding chapters.
3D-hahmojen toteutus mobiilipeliin
Kemppainen, Matti
2012-01-01
Mobiilipelien suosio on kasvanut räjähdysmäisesti viime vuosina älypuhelinten kehittymisen myötä. Tässä opinnäytetyössä selvitetään kolmiulotteisen pelihahmon toteutusprosessi mobiilipeliin. Lisäksi pohditaan maksullisten ja ilmaisten ohjelmien eroja toteutuksessa. Pelihahmojen toteutus perustuu mobiilipeliprojektiin peliyrityksessä, jossa työskentelin graafikkona. Ohjelmien vertailussa on mukana 3D Studio Max, Blender 3D, Photoshop ja GIMP. Käytännön osuudessa käydään läpi 3D-pelihahmon...
Pharmacophore definition and 3D searches.
Langer, T; Wolber, G
2004-12-01
The most common pharmacophore building concepts based on either 3D structure of the target or ligand information are discussed together with the application of such models as queries for 3D database search. An overview of the key techniques available on the market is given and differences with respect to algorithms used and performance obtained are highlighted. Pharmacophore modelling and 3D database search are shown to be successful tools for enriching screening experiments aimed at the discovery of novel bio-active compounds.: PMID:24981486
Computer Modelling of 3D Geological Surface
Kodge B. G.
2011-02-01
Full Text Available The geological surveying presently uses methods and tools for the computer modeling of 3D-structures of the geographical subsurface and geotechnical characterization as well as the application of geoinformation systems for management and analysis of spatial data, and their cartographic presentation. The objectives of this paper are to present a 3D geological surface model of Latur district in Maharashtra state of India. This study is undertaken through the several processes which are discussed in this paper to generate and visualize the automated 3D geological surface model of a projected area.
3D face modeling, analysis and recognition
Daoudi, Mohamed; Veltkamp, Remco
2013-01-01
3D Face Modeling, Analysis and Recognition presents methodologies for analyzing shapes of facial surfaces, develops computational tools for analyzing 3D face data, and illustrates them using state-of-the-art applications. The methodologies chosen are based on efficient representations, metrics, comparisons, and classifications of features that are especially relevant in the context of 3D measurements of human faces. These frameworks have a long-term utility in face analysis, taking into account the anticipated improvements in data collection, data storage, processing speeds, and application s
Computer Modelling of 3D Geological Surface
Kodge, B G
2011-01-01
The geological surveying presently uses methods and tools for the computer modeling of 3D-structures of the geographical subsurface and geotechnical characterization as well as the application of geoinformation systems for management and analysis of spatial data, and their cartographic presentation. The objectives of this paper are to present a 3D geological surface model of Latur district in Maharashtra state of India. This study is undertaken through the several processes which are discussed in this paper to generate and visualize the automated 3D geological surface model of a projected area.
3D tulostus - digitaalisesta mallista esineeksi
Muurinen, Kimmo
2013-01-01
Tässä opinnäytetyössä esitellään 3D tulostuksen tekniikka ja materiaaleja, suunnitellaan ja tuotetaan esimerkkikappaleen digitaalinen malli, sekä tulostetaan muovinen esine digi-taalisen mallin pohjalta. Työn tavoitteena on perehdyttää lukija prosessiin, jossa itse tuotettu digitaalinen malli tulostetaan käyttäen harrastajakäyttöön tarkoitettua edullista 3D tulostinta. Esimerkkikappaleen eri osien mallinnusprosessi näytetään kokonaisuudessaan ja kerro-taan perusteita 3D mallinnuksesta...
Ohkawa, Shinichi [Isehara Kyohdoh Hospital, Kanagawa (Japan); Hiramatsu, Kyoichi
1995-04-01
This report introduces a new 3D-MR cholangio-angiography technique using 3D Fast SE MR cholangiography and 3D phase contrast MR angiography for obstructive jaundice. In all eight cases, dilated biliary tracts as well as portal veins were clearly visualized in the same image. This new technique helped to determine the operability and surgical strategy for cases with obstructive jaundice. It also provided anatomical guidance for surgical procedures. This study suggests that this technique may replace the currently used modalities for obstructive jaundice. (author).
A high capacity 3D steganography algorithm.
Chao, Min-Wen; Lin, Chao-hung; Yu, Cheng-Wei; Lee, Tong-Yee
2009-01-01
In this paper, we present a very high-capacity and low-distortion 3D steganography scheme. Our steganography approach is based on a novel multilayered embedding scheme to hide secret messages in the vertices of 3D polygon models. Experimental results show that the cover model distortion is very small as the number of hiding layers ranges from 7 to 13 layers. To the best of our knowledge, this novel approach can provide much higher hiding capacity than other state-of-the-art approaches, while obeying the low distortion and security basic requirements for steganography on 3D models. PMID:19147891
Killing tensors and canonical geometry
The systematic derivation of constants of the motion, based on Killing tensors and the gauge covariant approach, is outlined. Quantum dots are shown to support second-, third- and fourth-rank Killing tensors. (paper)
HOSVD-Based 3D Active Appearance Model: Segmentation of Lung Fields in CT Images.
Wang, Qingzhu; Kang, Wanjun; Hu, Haihui; Wang, Bin
2016-07-01
An Active Appearance Model (AAM) is a computer vision model which can be used to effectively segment lung fields in CT images. However, the fitting result is often inadequate when the lungs are affected by high-density pathologies. To overcome this problem, we propose a Higher-order Singular Value Decomposition (HOSVD)-based Three-dimensional (3D) AAM. An evaluation was performed on 310 diseased lungs form the Lung Image Database Consortium Image Collection. Other contemporary AAMs operate directly on patterns represented by vectors, i.e., before applying the AAM to a 3D lung volume,it has to be vectorized first into a vector pattern by some technique like concatenation. However, some implicit structural or local contextual information may be lost in this transformation. According to the nature of the 3D lung volume, HOSVD is introduced to represent and process the lung in tensor space. Our method can not only directly operate on the original 3D tensor patterns, but also efficiently reduce the computer memory usage. The evaluation resulted in an average Dice coefficient of 97.0 % ± 0.59 %, a mean absolute surface distance error of 1.0403 ± 0.5716 mm, a mean border positioning errors of 0.9187 ± 0.5381 pixel, and a Hausdorff Distance of 20.4064 ± 4.3855, respectively. Experimental results showed that our methods delivered significant and better segmentation results, compared with the three other model-based lung segmentation approaches, namely 3D Snake, 3D ASM and 3D AAM. PMID:27277277
Ziegel, Johanna; Nyengaard, Jens Randel; Jensen, Eva B. Vedel
In the present paper, statistical procedures for estimating shape and orientation of arbitrary three-dimensional particles are developed. The focus of this work is on the case where the particles cannot be observed directly, but only via sections. Volume tensors are used for describing particle s...
We present a unified framework to describe lattice gauge theories by means of tensor networks: this framework is efficient as it exploits the high local symmetry content native to these systems by describing only the gauge invariant subspace. Compared to a standard tensor network description, the gauge invariant model allows one to increase real and imaginary time evolution up to a factor that is square of the dimension of the link variable. The gauge invariant tensor network description is based on the quantum link formulation, a compact and intuitive formulation for gauge theories on the lattice, which is alternative to and can be combined with the global symmetric tensor network description. We present some paradigmatic examples that show how this architecture might be used to describe the physics of condensed matter and high-energy physics systems. Finally, we present a cellular automata analysis which estimates the gauge invariant Hilbert space dimension as a function of the number of lattice sites that might guide the search for effective simplified models of complex theories. (paper)
XML3D and Xflow: combining declarative 3D for the Web with generic data flows.
Klein, Felix; Sons, Kristian; Rubinstein, Dmitri; Slusallek, Philipp
2013-01-01
Researchers have combined XML3D, which provides declarative, interactive 3D scene descriptions based on HTML5, with Xflow, a language for declarative, high-performance data processing. The result lets Web developers combine a 3D scene graph with data flows for dynamic meshes, animations, image processing, and postprocessing. PMID:24808080
Simplifying Tensor Polynomials with Indices
Balfagón, A
1998-01-01
We are presenting an algorithm capable of simplifying tensor polynomials with indices when the building tensors have index symmetry properties. These properties include simple symmetry, cyclicity and those due to the presence of partial and covariant derivatives. We are also including some examples using the Riemann tensor as a paradigm. The algorithm is part of a Mathematica package called Tools of Tensor Calculus (TTC) [web address: http//baldufa.upc.es/ttc
Diffusion tensor image registration using polynomial expansion
In this paper, we present a deformable registration framework for the diffusion tensor image (DTI) using polynomial expansion. The use of polynomial expansion in image registration has previously been shown to be beneficial due to fast convergence and high accuracy. However, earlier work was developed only for 3D scalar medical image registration. In this work, it is shown how polynomial expansion can be applied to DTI registration. A new measurement is proposed for DTI registration evaluation, which seems to be robust and sensitive in evaluating the result of DTI registration. We present the algorithms for DTI registration using polynomial expansion by the fractional anisotropy image, and an explicit tensor reorientation strategy is inherent to the registration process. Analytic transforms with high accuracy are derived from polynomial expansion and used for transforming the tensor's orientation. Three measurements for DTI registration evaluation are presented and compared in experimental results. The experiments for algorithm validation are designed from simple affine deformation to nonlinear deformation cases, and the algorithms using polynomial expansion give a good performance in both cases. Inter-subject DTI registration results are presented showing the utility of the proposed method. (paper)
Nonlaser-based 3D surface imaging
Lu, Shin-yee; Johnson, R.K.; Sherwood, R.J. [Lawrence Livermore National Lab., CA (United States)
1994-11-15
3D surface imaging refers to methods that generate a 3D surface representation of objects of a scene under viewing. Laser-based 3D surface imaging systems are commonly used in manufacturing, robotics and biomedical research. Although laser-based systems provide satisfactory solutions for most applications, there are situations where non laser-based approaches are preferred. The issues that make alternative methods sometimes more attractive are: (1) real-time data capturing, (2) eye-safety, (3) portability, and (4) work distance. The focus of this presentation is on generating a 3D surface from multiple 2D projected images using CCD cameras, without a laser light source. Two methods are presented: stereo vision and depth-from-focus. Their applications are described.
Curating Architectural 3D CAD Models
MacKenzie Smith
2009-06-01
Full Text Available Normal 0 Increasing demand to manage and preserve 3-dimensional models for a variety of physical phenomena (e.g., building and engineering designs, computer games, or scientific visualizations is creating new challenges for digital archives. Preserving 3D models requires identifying technical formats for the models that can be maintained over time, and the available formats offer different advantages and disadvantages depending on the intended future uses of the models. Additionally, the metadata required to manage 3D models is not yet standardized, and getting intellectual proposal rights for digital models is uncharted territory. The FACADE Project at MIT is investigating these challenges in the architecture, engineering and construction (AEC industry and has developed recommendations and systems to support digital archives in dealing with digital 3D models and related data. These results can also be generalized to other domains doing 3D modeling.
3D Visualization of Recent Sumatra Earthquake
Nayak, Atul; Kilb, Debi
2005-04-01
Scientists and visualization experts at the Scripps Institution of Oceanography have created an interactive three-dimensional visualization of the 28 March 2005 magnitude 8.7 earthquake in Sumatra. The visualization shows the earthquake's hypocenter and aftershocks recorded until 29 March 2005, and compares it with the location of the 26 December 2004 magnitude 9 event and the consequent seismicity in that region. The 3D visualization was created using the Fledermaus software developed by Interactive Visualization Systems (http://www.ivs.unb.ca/) and stored as a ``scene'' file. To view this visualization, viewers need to download and install the free viewer program iView3D (http://www.ivs3d.com/products/iview3d).
Transportstromen verschuiven door toepassing 3-D
Janssen, G.R.
2014-01-01
3-D printing is aan een gestage opmars bezig.ln een paar jaar tijd is er een miljardenmarkt ontstaan die exponentieel groeit. TNO deed onderzoek naar de impact van deze ontwikkelingen op supply chains.
3DSEM: A 3D microscopy dataset.
Tafti, Ahmad P; Kirkpatrick, Andrew B; Holz, Jessica D; Owen, Heather A; Yu, Zeyun
2016-03-01
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. PMID:26779561
Copper Electrodeposition for 3D Integration
Beica, Rozalia; Ritzdorf, Tom
2008-01-01
Two dimensional (2D) integration has been the traditional approach for IC integration. Due to increasing demands for providing electronic devices with superior performance and functionality in more efficient and compact packages, has driven the semiconductor industry to develop more advanced packaging technologies. Three-dimensional (3D) approaches address both miniaturization and integration required for advanced and portable electronic products. Vertical integration proved to be essential in achieving a greater integration flexibility of disparate technologies, reason for which a general trend of transition from 2D to 3D integration is currently being observed in the industry. 3D chip integration using through silicon via (TSV) copper is considered one of the most advanced technologies among all different types of 3D packaging technologies. Copper electrodeposition is one of technologies that enable the formation of TSV structures. Because of its well-known application for copper damascene, it was believed ...
3D-printed bioanalytical devices
Bishop, Gregory W.; Satterwhite-Warden, Jennifer E.; Kadimisetty, Karteek; Rusling, James F.
2016-07-01
While 3D printing technologies first appeared in the 1980s, prohibitive costs, limited materials, and the relatively small number of commercially available printers confined applications mainly to prototyping for manufacturing purposes. As technologies, printer cost, materials, and accessibility continue to improve, 3D printing has found widespread implementation in research and development in many disciplines due to ease-of-use and relatively fast design-to-object workflow. Several 3D printing techniques have been used to prepare devices such as milli- and microfluidic flow cells for analyses of cells and biomolecules as well as interfaces that enable bioanalytical measurements using cellphones. This review focuses on preparation and applications of 3D-printed bioanalytical devices.
Mobile 3D Viewer Supporting RFID System
Kim, J. J.; Yang, S. W.; Choi, Y. [Chungang Univ., Seoul (Korea, Republic of)
2007-07-01
As hardware capabilities of mobile devices are being rapidly enhanced, applications based upon mobile devices are also being developed in wider areas. In this paper, a prototype mobile 3D viewer with the object identification through RFID system is presented. To visualize 3D engineering data such as CAD data, we need a process to compute triangulated data from boundary based surface like B-rep solid or trimmed surfaces. Since existing rendering engines on mobile devices do not provide triangulation capability, mobile 3D programs have focused only on an efficient handling with pre-tessellated geometry. We have developed a light and fast triangulation process based on constrained Delaunay triangulation suitable for mobile devices in the previous research. This triangulation software is used as a core for the mobile 3D viewer on a PDA with RFID system that may have potentially wide applications in many areas.
Mobile 3D Viewer Supporting RFID System
As hardware capabilities of mobile devices are being rapidly enhanced, applications based upon mobile devices are also being developed in wider areas. In this paper, a prototype mobile 3D viewer with the object identification through RFID system is presented. To visualize 3D engineering data such as CAD data, we need a process to compute triangulated data from boundary based surface like B-rep solid or trimmed surfaces. Since existing rendering engines on mobile devices do not provide triangulation capability, mobile 3D programs have focused only on an efficient handling with pre-tessellated geometry. We have developed a light and fast triangulation process based on constrained Delaunay triangulation suitable for mobile devices in the previous research. This triangulation software is used as a core for the mobile 3D viewer on a PDA with RFID system that may have potentially wide applications in many areas
Pentingnya Pengetahuan Anatomi untuk 3D Artist
Anton Sugito Kurniawan
2011-03-01
Full Text Available No matter how far the current technological advances, anatomical knowledge will still be needed as a basis for making a good character design. Understanding anatomy will help us in the placement of the articulation of muscles and joints, thus more realistic modeling of 3d characters will be achieved in the form and movement. As a 3d character artist, anatomy should be able to inform in every aspect of our work. Each 3D/CG (Computer Graphics-artist needs to know how to use software applications, but what differentiates a 3d artist with a computer operator is an artistic vision and understanding of the basic shape of the human body. Artistic vision could not easily be taught, but a CG-artist may study it on their own from which so many reference sources may help understand and deepen their knowledge of anatomy.
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.
Networked 3D Virtual Museum System
无
2003-01-01
Virtual heritage has become increasingly important in the conservation, preservation, and interpretation of our cultural and natural history. Moreover, rapid advances in digital technologies in recent years offer virtual heritage new direction. This paper introduces our approach toward a networked 3D virtual museum system, especially, how to model, manage, present virtual heritages and furthermore how to use computer network for the share of virtual heritage in the networked virtual environment. This paper first addresses a 3D acquisition and processing technique for virtual heritage modeling and shows some illustrative examples. Then, this paper describes a management of virtual heritage assets that are composed by various rich media. This paper introduces our schemes to present the virtual heritages, which include 3D virtual heritage browser system, CAVE system, and immersive VR theater. Finally, this paper presents the new direction of networked 3D virtual museum of which main idea is remote guide of the virtual heritage using the mixed reality technique.
Advanced 3D Object Identification System Project
National Aeronautics and Space Administration — Optra will build an Advanced 3D Object Identification System utilizing three or more high resolution imagers spaced around a launch platform. Data from each imager...
3D-printed bioanalytical devices.
Bishop, Gregory W; Satterwhite-Warden, Jennifer E; Kadimisetty, Karteek; Rusling, James F
2016-07-15
While 3D printing technologies first appeared in the 1980s, prohibitive costs, limited materials, and the relatively small number of commercially available printers confined applications mainly to prototyping for manufacturing purposes. As technologies, printer cost, materials, and accessibility continue to improve, 3D printing has found widespread implementation in research and development in many disciplines due to ease-of-use and relatively fast design-to-object workflow. Several 3D printing techniques have been used to prepare devices such as milli- and microfluidic flow cells for analyses of cells and biomolecules as well as interfaces that enable bioanalytical measurements using cellphones. This review focuses on preparation and applications of 3D-printed bioanalytical devices. PMID:27250897
3D Biomaterial Microarrays for Regenerative Medicine
Gaharwar, Akhilesh K.; Arpanaei, Ayyoob; Andresen, Thomas Lars;
2015-01-01
Three dimensional (3D) biomaterial microarrays hold enormous promise for regenerative medicine because of their ability to accelerate the design and fabrication of biomimetic materials. Such tissue-like biomaterials can provide an appropriate microenvironment for stimulating and controlling stem...
Measuring Visual Closeness of 3-D Models
Morales, Jose A.
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
3D-FPA Hybridization Improvements Project
National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) is a small business, which has developed a compact, eye-safe 3D Flash LIDARTM Camera (FLC) well suited for real-time...
3D Flash LIDAR Space Laser Project
National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc (ASC) is a small business, which has developed a compact, eye-safe 3D Flash LIDARTM Camera (FLC) well suited for real-time...
3D Reconstruction of NMR Images
Peter Izak
2007-01-01
Full Text Available This paper introduces experiment of 3D reconstruction NMR images scanned from magnetic resonance device. There are described methods which can be used for 3D reconstruction magnetic resonance images in biomedical application. The main idea is based on marching cubes algorithm. For this task was chosen sophistication method by program Vision Assistant, which is a part of program LabVIEW.
Recognition of Symmetric 3D Bodies
Suk, Tomáš; Flusser, Jan
2014-01-01
Roč. 6, č. 3 (2014), s. 722-757. ISSN 2073-8994 R&D Projects: GA ČR GAP103/11/1552 Institutional support: RVO:67985556 Keywords : rotation symmetry * reflection symmetry * 3D complex moments * 3D rotation invariants Subject RIV: JD - Computer Applications, Robotics Impact factor: 0.826, year: 2014 http://library.utia.cas.cz/separaty/2014/ZOI/suk-0431156.pdf
Multifractal modelling and 3D lacunarity analysis
This study presents a comparative evaluation of lacunarity of 3D grey level models with different types of inhomogeneity. A new method based on the 'Relative Differential Box Counting' was developed to estimate the lacunarity features of grey level volumes. To validate our method, we generated a set of 3D grey level multifractal models with random, anisotropic and hierarchical properties. Our method gives a lacunarity measurement correlated with the theoretical one and allows a better model classification compared with a classical approach.
The properties of an extension of the new massive 3D gravity by scalar matter with Higgs-like self-interaction are investigated. Its perturbative unitarity consistency is verified for a family of cosmological bounce solutions found by the superpotential method. They correspond to the lower bound λ=-1 of the BHT unitarity window and describe eternally accelerated 3D Universe between two initial/final stable dS3 vacua states.
3D Printing for Tissue Engineering
Richards, Dylan Jack; Tan, Yu; Jia, Jia; Yao, Hai; Mei, Ying
2013-01-01
Tissue engineering aims to fabricate functional tissue for applications in regenerative medicine and drug testing. More recently, 3D printing has shown great promise in tissue fabrication with a structural control from micro- to macro-scale by using a layer-by-layer approach. Whether through scaffold-based or scaffold-free approaches, the standard for 3D printed tissue engineering constructs is to provide a biomimetic structural environment that facilitates tissue formation and promotes host ...
Ajosimulaation toteutus Unity 3D -pelimoottorilla
Tapio, Tomi
2014-01-01
Opinnäytetyön aiheena oli ajosimulaation toteutus Unity 3D -pelimoottorilla. Työn idea syntyi, kun ENVI-oppimisympäristöön tarvittiin liikealustalla toimiva ambulanssisimulaattori, jonka avulla opiskelijat voisivat oppia erilaisia hoitotilanteita. ENVI on terveydenalan opiskelijoiden virtuaalinen oppimisympäristö. Työn toimeksiantaja oli ohjelmistotekniikan laboratorio pLAB, joka sijaitsee Lapin ammattikorkeakoulun tiloissa Rantavitikalla. Opinnäytetyön tavoitteena oli toteuttaa Unity 3D ...
Luovasta konseptisuunnittelusta 3D-mainoselokuvaan
Salo, Suvi
2015-01-01
Insinöörityön tavoite oli luoda 3D-mainoselokuva myynnin tueksi ja nostaa esiin IT-alan yrityksen ja sen yksikön tuottamien palveluiden laajuutta ja yrityksen tapaa tuottaa tulostuspalvelua. Toteutettu mainoselokuva on tarkoitettu julkaistavaksi verkossa yrityksen omalla Youtube-kanavalla ja verkkosivuilla. 3D-mainoselokuvan suunnittelussa käytettiin luovan konseptisuunnittelun keinoja jalostaa tarina kohderyhmälähtöiseksi. Aluksi selvitettiin asiakasrajapinnan haastattelujen avulla kohde...
3D printing: technology and processing
Kurinov, Ilya
2016-01-01
The objective of the research was to improve the process of 3D printing on the laboratory machine. In the study processes of designing, printing and post-print-ing treatment were improved. The study was commissioned by Mikko Ruotsalainen, head of the laboratory. The data was collected during the test work. All the basic information about 3D printing was taken from the Internet or library. As the results of the project higher model accuracy, solutions for post-printing treatment, printin...
3D printing of functional structures
Krijnen, G.J.M.
2016-01-01
The technology colloquial known as ‘3D printing’ has developed in such diversity in printing technologies and application fields that meanwhile it seems anything is possible. However, clearly the ideal 3D Printer, with high resolution, multi-material capability, fast printing, etc. is yet to be developed. Nevertheless, one can al- ready start to wonder what possibilities for electrical engineering applications will become available in the near future. Here I try to give a brief and balanced o...
Louzada, H L C; Sotkov, G M
2010-01-01
The properties of an extension of the New Massive 3D Gravity by scalar matter with Higgs-like self-interaction are investigated. Its perturbative unitarity consistency is verified for a family of cosmological Bounce solutions found by the superpotential method. They correspond to the lower bound ${\\lambda = -1}$ of the BHT unitarity window and describe eternally accelerated 3D Universe between two initial/final stable $dS_3$ vacua states.
3D Printing Electrically Small Spherical Antennas
Kim, Oleksiy S.
2013-01-01
3D printing is applied for rapid prototyping of an electrically small spherical wire antenna. The model is first printed in plastic and subsequently covered with several layers of conductive paint. Measured results are in good agreement with simulations.......3D printing is applied for rapid prototyping of an electrically small spherical wire antenna. The model is first printed in plastic and subsequently covered with several layers of conductive paint. Measured results are in good agreement with simulations....
Visual Attention in 3D Video Games.
Seif El-Nasr, Magy; Yan, Su
2006-01-01
Understanding players’ visual attention patterns within an interactive 3D game environment is an important research area that can improve game level design and graphics. Several graphics techniques use a perception based rendering method to enhance graphics quality while achieving the fast rendering speed required for fast-paced 3D video games. Game designers can also enhance game play by adjusting the level design, texture and color choices, and objects’ locations, if such decisions are info...
Embedding 3D into multipurpose cadastre
A. A. Rahman; T. C. Hua; P. J. M. Van Oosterom
2011-01-01
There is no doubt that the cadastral map provides a useful entrance to information in a land parcel based information system. However, such information system could be made more meaningful and useful if it can be extended for multiple usages with multi data layers, and in three-dimensions (3D). Currently, many national mapping and cadastral agencies (NMCAs) and users deal with complex situations, and we believe that 3D could enhance the understanding of the situations better. This paper descr...
Improving Accuracy for 3D RFID Localization
Chun Hung Wong; Yan Shun Cheng; Tse Lung Wong; Jinsong Han; Yiyang Zhao
2012-01-01
Radio Frequency Identification (RFID) becomes a prevalent labeling and localizing technique in the recent years. Deploying indoor RFID localization systems facilitates many applications. Previous approaches, however, are most based on 2D design and cannot provide 3D location information. The lack of one-dimensional information may lead 2D-based systems to inaccurate localization. In this paper, we develop an indoor 3D RFID localization system based on active tag array. In particular, we emplo...
LandSIM3D: modellazione in real time 3D di dati geografici
Lambo Srl Lambo Srl
2009-01-01
LandSIM3D: realtime 3D modelling of geographic dataLandSIM3D allows to model in 3D an existing landscape in a few hours only and geo-referenced offering great landscape analysis and understanding tools. 3D projects can then be inserted into the existing landscape with ease and precision. The project alternatives and impact can then be visualized and studied into their immediate environmental. The complex evolution of the landscape in the future can also be simulated and the landscape model ca...
Adaptive Enhancement of 3D Scenes using Hierarchical Registration of Texture-Mapped 3D Models
Ramalingam, Srikumar; Lodha, Suresh
2003-01-01
Adaptive fusion of new information in a 3D urban scene is an important goal to achieve in computer vision, graphics, and visualization. In this work we acquire new image pairs of a scene from closer distances and extract 3D models of successively higher resolutions. We present a new hierarchical approach to register these texture-mapped 3D models with a coarse 3D texture mapped model of an urban scene. First, we use the standard reconstruction algorithm to construct 3D models after establishi...
X3D Interoperability and X3D Progress, Common Problems versus Stable Growth [video
Tourtelotte, Dale R.; Brutzman, Don
2010-01-01
In large measure, the vision of making it easier to create and use 3D spatial data has been achieved through The Extensible 3D (X3D) Earth project. This project created a standards-based 3D visualization infrastructure for visualizing all manner of real-world objects and information constructs in a geospatial context. The ability to archive models using stable commercial tools and noncommercial international standards ensures that 3D work can remain accessible and repeatable for many years to...
Developing a 3D virtual geology field trip in Unity 3D: reflection of our experiences
Minocha, Shailey
2014-01-01
As a part of The OpenScience Laboratory(), an initiative of The Open University, UK and The Wolfson Foundation, we have developed a 3D simulation of a Geology field trip (), using the Unity 3D software (). The learning activities within the 3D App are designed to mirror the experience of a real field trip. The design and development of the 3D App has involved people with diverse skills in a University environment while working closely with an external developer who brought in Unity and 3D mod...
PRETVORBA 3D MODELOV IZ PROGRAMA BLENDER V BINARNI ZAPIS IGRALNEGA POGONA PRISM3D
Lušenc, Simon
2014-01-01
Magistrsko delo predstavi binarni zapis 3D modelov, uporabljenih v igralnem pogonu Prism3D in razvoj dodatka za pretvorbo 3D modelov s programskim orodjem Blender, ki ga tudi najprej na kratko opišemo. V nadaljevanju analiziramo zapise uporabljenih datotek, kar nam omogoči razvoj dodatka za uvoz in izvoz 3D modela, uporabljenega v igralnem pogonu Prism3D. Po predstavljeni izdelavi dodatka z vizualno primerjavo ocenimo njegovo uspešnosti in podamo možne izboljšave.
Auto convergence for stereoscopic 3D cameras
Zhang, Buyue; Kothandaraman, Sreenivas; Batur, Aziz Umit
2012-03-01
Viewing comfort is an important concern for 3-D capable consumer electronics such as 3-D cameras and TVs. Consumer generated content is typically viewed at a close distance which makes the vergence-accommodation conflict particularly pronounced, causing discomfort and eye fatigue. In this paper, we present a Stereo Auto Convergence (SAC) algorithm for consumer 3-D cameras that reduces the vergence-accommodation conflict on the 3-D display by adjusting the depth of the scene automatically. Our algorithm processes stereo video in realtime and shifts each stereo frame horizontally by an appropriate amount to converge on the chosen object in that frame. The algorithm starts by estimating disparities between the left and right image pairs using correlations of the vertical projections of the image data. The estimated disparities are then analyzed by the algorithm to select a point of convergence. The current and target disparities of the chosen convergence point determines how much horizontal shift is needed. A disparity safety check is then performed to determine whether or not the maximum and minimum disparity limits would be exceeded after auto convergence. If the limits would be exceeded, further adjustments are made to satisfy the safety limits. Finally, desired convergence is achieved by shifting the left and the right frames accordingly. Our algorithm runs real-time at 30 fps on a TI OMAP4 processor. It is tested using an OMAP4 embedded prototype stereo 3-D camera. It significantly improves 3-D viewing comfort.
Assessing 3d Photogrammetry Techniques in Craniometrics
Moshobane, M. C.; de Bruyn, P. J. N.; Bester, M. N.
2016-06-01
Morphometrics (the measurement of morphological features) has been revolutionized by the creation of new techniques to study how organismal shape co-varies with several factors such as ecophenotypy. Ecophenotypy refers to the divergence of phenotypes due to developmental changes induced by local environmental conditions, producing distinct ecophenotypes. None of the techniques hitherto utilized could explicitly address organismal shape in a complete biological form, i.e. three-dimensionally. This study investigates the use of the commercial software, Photomodeler Scanner® (PMSc®) three-dimensional (3D) modelling software to produce accurate and high-resolution 3D models. Henceforth, the modelling of Subantarctic fur seal (Arctocephalus tropicalis) and Antarctic fur seal (Arctocephalus gazella) skulls which could allow for 3D measurements. Using this method, sixteen accurate 3D skull models were produced and five metrics were determined. The 3D linear measurements were compared to measurements taken manually with a digital caliper. In addition, repetitive measurements were recorded by varying researchers to determine repeatability. To allow for comparison straight line measurements were taken with the software, assuming that close accord with all manually measured features would illustrate the model's accurate replication of reality. Measurements were not significantly different demonstrating that realistic 3D skull models can be successfully produced to provide a consistent basis for craniometrics, with the additional benefit of allowing non-linear measurements if required.
Evaluation of Bayesian tensor estimation using tensor coherence
Kim, Dae-Jin; Park, Hae-Jeong [Laboratory of Molecular Neuroimaging Technology, Brain Korea 21 Project for Medical Science, Yonsei University, College of Medicine, Seoul (Korea, Republic of); Kim, In-Young [Department of Biomedical Engineering, Hanyang University, Seoul (Korea, Republic of); Jeong, Seok-Oh [Department of Statistics, Hankuk University of Foreign Studies, Yongin (Korea, Republic of)], E-mail: parkhj@yuhs.ac
2009-06-21
Fiber tractography, a unique and non-invasive method to estimate axonal fibers within white matter, constructs the putative streamlines from diffusion tensor MRI by interconnecting voxels according to the propagation direction defined by the diffusion tensor. This direction has uncertainties due to the properties of underlying fiber bundles, neighboring structures and image noise. Therefore, robust estimation of the diffusion direction is essential to reconstruct reliable fiber pathways. For this purpose, we propose a tensor estimation method using a Bayesian framework, which includes an a priori probability distribution based on tensor coherence indices, to utilize both the neighborhood direction information and the inertia moment as regularization terms. The reliability of the proposed tensor estimation was evaluated using Monte Carlo simulations in terms of accuracy and precision with four synthetic tensor fields at various SNRs and in vivo human data of brain and calf muscle. Proposed Bayesian estimation demonstrated the relative robustness to noise and the higher reliability compared to the simple tensor regression.
Minkowski tensor shape analysis of cellular, granular and porous structures.
Schröder-Turk, G E; Mickel, W; Kapfer, S C; Klatt, M A; Schaller, F M; Hoffmann, M J F; Kleppmann, N; Armstrong, P; Inayat, A; Hug, D; Reichelsdorfer, M; Peukert, W; Schwieger, W; Mecke, K
2011-06-17
Predicting physical properties of materials with spatially complex structures is one of the most challenging problems in material science. One key to a better understanding of such materials is the geometric characterization of their spatial structure. Minkowski tensors are tensorial shape indices that allow quantitative characterization of the anisotropy of complex materials and are particularly well suited for developing structure-property relationships for tensor-valued or orientation-dependent physical properties. They are fundamental shape indices, in some sense being the simplest generalization of the concepts of volume, surface and integral curvatures to tensor-valued quantities. Minkowski tensors are based on a solid mathematical foundation provided by integral and stochastic geometry, and are endowed with strong robustness and completeness theorems. The versatile definition of Minkowski tensors applies widely to different types of morphologies, including ordered and disordered structures. Fast linear-time algorithms are available for their computation. This article provides a practical overview of the different uses of Minkowski tensors to extract quantitative physically-relevant spatial structure information from experimental and simulated data, both in 2D and 3D. Applications are presented that quantify (a) alignment of co-polymer films by an electric field imaged by surface force microscopy; (b) local cell anisotropy of spherical bead pack models for granular matter and of closed-cell liquid foam models; (c) surface orientation in open-cell solid foams studied by X-ray tomography; and (d) defect densities and locations in molecular dynamics simulations of crystalline copper. PMID:21681830
3D morphological and micromechanical modeling of cementitious materials
The goal of this thesis is to develop morphological models of cementitious materials and use these models to study their local and effective response. To this aim, 3D images of cementitious materials (mortar and concrete), obtained by micro-tomography, are studied. First, the mortar image is segmented in order to obtain an image of a real microstructure, to be used for linear elasticity computations. The image of concrete is used, after being processed, to determine various morphological characteristics of the material. A random model of concrete is then developed and validated by means of morphological data. This model is made up of three phases, corresponding to the matrix, aggregates and voids. The aggregates phase is modelled by implantation of Poisson polyhedra without overlap. For this purpose, an algorithm suited to the vector generation of Poisson polyhedra is introduced and validated with morphological measurements. Finally, the effective linear elastic properties of the mortar and other simulated microstructures are estimated with the FFT (Fast-Fourier Transform) method, for various contrasts between the aggregates and matrix' Young moduli. To complete this work, focused on effective properties, an analysis of the local elastic response in the matrix phase is undertaken, in order to determine the spatial arrangement between stress concentration zones in the matrix and the phases of the microstructure (aggregates and voids). Moreover, a statistical fields characterization, in the matrix, is achieved, including the determination of the Representative Volume Element (RVE) size. Furthermore, a comparison between effective and local elastic properties obtained from microstructures containing polyhedra and spheres is carried out. (author)
RAG-3D: a search tool for RNA 3D substructures.
Zahran, Mai; Sevim Bayrak, Cigdem; Elmetwaly, Shereef; Schlick, Tamar
2015-10-30
To address many challenges in RNA structure/function prediction, the characterization of RNA's modular architectural units is required. Using the RNA-As-Graphs (RAG) database, we have previously explored the existence of secondary structure (2D) submotifs within larger RNA structures. Here we present RAG-3D-a dataset of RNA tertiary (3D) structures and substructures plus a web-based search tool-designed to exploit graph representations of RNAs for the goal of searching for similar 3D structural fragments. The objects in RAG-3D consist of 3D structures translated into 3D graphs, cataloged based on the connectivity between their secondary structure elements. Each graph is additionally described in terms of its subgraph building blocks. The RAG-3D search tool then compares a query RNA 3D structure to those in the database to obtain structurally similar structures and substructures. This comparison reveals conserved 3D RNA features and thus may suggest functional connections. Though RNA search programs based on similarity in sequence, 2D, and/or 3D structural elements are available, our graph-based search tool may be advantageous for illuminating similarities that are not obvious; using motifs rather than sequence space also reduces search times considerably. Ultimately, such substructuring could be useful for RNA 3D structure prediction, structure/function inference and inverse folding. PMID:26304547
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)
3-D SAR image formation from sparse aperture data using 3-D target grids
Bhalla, Rajan; Li, Junfei; Ling, Hao
2005-05-01
The performance of ATR systems can potentially be improved by using three-dimensional (3-D) SAR images instead of the traditional two-dimensional SAR images or one-dimensional range profiles. 3-D SAR image formation of targets from radar backscattered data collected on wide angle, sparse apertures has been identified by AFRL as fundamental to building an object detection and recognition capability. A set of data has been released as a challenge problem. This paper describes a technique based on the concept of 3-D target grids aimed at the formation of 3-D SAR images of targets from sparse aperture data. The 3-D target grids capture the 3-D spatial and angular scattering properties of the target and serve as matched filters for SAR formation. The results of 3-D SAR formation using the backhoe public release data are presented.
3D-mallien muokkaus 3D-tulostamista varten CAD-ohjelmilla
Lehtimäki, Jarmo
2013-01-01
Insinöörityössäni käsitellään 3D-mallien tulostamista ja erityisesti 3D-mallien mallintamista niin, että kappaleiden valmistaminen 3D-tulostimella onnistuisi mahdollisimman hyvin. Työ tehtiin Prohoc Oy:lle, joka sijaitsee Vaasassa. 3D-tulostuspalveluun tuli jatkuvasti 3D-malleja, joiden tulostuksessa oli ongelmia. Työssäni tutkin näiden ongelmien syntyä ja tein ohjeita eri 3D-mallinnusohjelmille, joiden tarkoituksena on auttaa tekemään helpommin tulostettavia 3D-malleja. Työhön kuului myös et...
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
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.
A microfluidic device for 2D to 3D and 3D to 3D cell navigation
Shamloo, Amir; Amirifar, Leyla
2016-01-01
Microfluidic devices have received wide attention and shown great potential in the field of tissue engineering and regenerative medicine. Investigating cell response to various stimulations is much more accurate and comprehensive with the aid of microfluidic devices. In this study, we introduced a microfluidic device by which the matrix density as a mechanical property and the concentration profile of a biochemical factor as a chemical property could be altered. Our microfluidic device has a cell tank and a cell culture chamber to mimic both 2D to 3D and 3D to 3D migration of three types of cells. Fluid shear stress is negligible on the cells and a stable concentration gradient can be obtained by diffusion. The device was designed by a numerical simulation so that the uniformity of the concentration gradients throughout the cell culture chamber was obtained. Adult neural cells were cultured within this device and they showed different branching and axonal navigation phenotypes within varying nerve growth factor (NGF) concentration profiles. Neural stem cells were also cultured within varying collagen matrix densities while exposed to NGF concentrations and they experienced 3D to 3D collective migration. By generating vascular endothelial growth factor concentration gradients, adult human dermal microvascular endothelial cells also migrated in a 2D to 3D manner and formed a stable lumen within a specific collagen matrix density. It was observed that a minimum absolute concentration and concentration gradient were required to stimulate migration of all types of the cells. This device has the advantage of changing multiple parameters simultaneously and is expected to have wide applicability in cell studies.
A microfluidic device for 2D to 3D and 3D to 3D cell navigation
Microfluidic devices have received wide attention and shown great potential in the field of tissue engineering and regenerative medicine. Investigating cell response to various stimulations is much more accurate and comprehensive with the aid of microfluidic devices. In this study, we introduced a microfluidic device by which the matrix density as a mechanical property and the concentration profile of a biochemical factor as a chemical property could be altered. Our microfluidic device has a cell tank and a cell culture chamber to mimic both 2D to 3D and 3D to 3D migration of three types of cells. Fluid shear stress is negligible on the cells and a stable concentration gradient can be obtained by diffusion. The device was designed by a numerical simulation so that the uniformity of the concentration gradients throughout the cell culture chamber was obtained. Adult neural cells were cultured within this device and they showed different branching and axonal navigation phenotypes within varying nerve growth factor (NGF) concentration profiles. Neural stem cells were also cultured within varying collagen matrix densities while exposed to NGF concentrations and they experienced 3D to 3D collective migration. By generating vascular endothelial growth factor concentration gradients, adult human dermal microvascular endothelial cells also migrated in a 2D to 3D manner and formed a stable lumen within a specific collagen matrix density. It was observed that a minimum absolute concentration and concentration gradient were required to stimulate migration of all types of the cells. This device has the advantage of changing multiple parameters simultaneously and is expected to have wide applicability in cell studies. (paper)