The novel high-performance 3-D MT inverse solver
NASA Astrophysics Data System (ADS)
Kruglyakov, Mikhail; Geraskin, Alexey; Kuvshinov, Alexey
2016-04-01
We present novel, robust, scalable, and fast 3-D magnetotelluric (MT) inverse solver. The solver is written in multi-language paradigm to make it as efficient, readable and maintainable as possible. Separation of concerns and single responsibility concepts go through implementation of the solver. As a forward modelling engine a modern scalable solver extrEMe, based on contracting integral equation approach, is used. Iterative gradient-type (quasi-Newton) optimization scheme is invoked to search for (regularized) inverse problem solution, and adjoint source approach is used to calculate efficiently the gradient of the misfit. The inverse solver is able to deal with highly detailed and contrasting models, allows for working (separately or jointly) with any type of MT responses, and supports massive parallelization. Moreover, different parallelization strategies implemented in the code allow optimal usage of available computational resources for a given problem statement. To parameterize an inverse domain the so-called mask parameterization is implemented, which means that one can merge any subset of forward modelling cells in order to account for (usually) irregular distribution of observation sites. We report results of 3-D numerical experiments aimed at analysing the robustness, performance and scalability of the code. In particular, our computational experiments carried out at different platforms ranging from modern laptops to HPC Piz Daint (6th supercomputer in the world) demonstrate practically linear scalability of the code up to thousands of nodes.
3-D Inversion of MT Data for Imaging Deformation Fronts in NW Poland
NASA Astrophysics Data System (ADS)
Ślęzak, Katarzyna; Jóźwiak, Waldemar; Nowożyński, Krzysztof; Brasse, Heinrich
2016-07-01
The Pomerania region (northwest part of Poland) occupies a significant position, where the largest European tectonic boundary is situated. This is the area of the contact between the East European Craton (EEC) and the Paleozoic Platform (PP) and it is known as the Trans-European Suture Zone (TESZ). The TESZ was formed during Paleozoic time as a consequence of the collision of several crustal units and it extends from the Black Sea in the southeast to the British Isles in the northwest. It is a region of key importance for our understanding of the tectonic history of Europe. Previous magnetotelluric (MT) results, based on 2-D inverse modeling, show that the contact zone is of lithospheric discontinuity character and there are distinct differences in geoelectric structures between the Precambrian EEC, transitional zone (TESZ), and the younger PP. The presence of a significant conductor at mid and lower crustal depths was also shown. Thus, the main aim of the research presented here was to obtain detailed, 3-D images of electrical conductivity in the crust and upper mantle and its regional distribution below the TESZ in the northwest part of Poland. To accomplish this task we applied the latest 3-D inversion codes, which allowed us to get more realistic model geometries. Additionally, to confirm and complement the study, the Horizontal Magnetic Tensor (HMT) analysis was realized. This method gives us an opportunity to efficiently locate the position of well-conducting structures. As a result we obtain a clearer, three-dimensional model of conductivity distribution, where highly conductive rock complexes appear which we tentatively connected to deformation fronts.
NASA Astrophysics Data System (ADS)
Sass, P.; Ritter, O.; Rybin, A.; Batalev, V.
2012-12-01
Many geodynamic processes governing intra-continental collisional orogeny are largely unexplained and controversial. A key question is the state and dynamic behaviour of the lithosphere at middle and lower crustal levels while continental collision progresses. The Pamir - Tien Shan region in Central Asia may be the best location on Earth to study such lithospheric deformation processes in situ. The mountain ranges and high plateaus formed at the tip of the north-western Indian promontory through the Cenozoic experienced rates of shortening similar to the adjacent Himalaya-Tibet system. Today, the Pamir - Tien Shan orogenic belt hosts some of the deepest active intra-continental subduction zones on Earth and absorbs the highest strain rate over the shortest distance that is manifested in the India-Asia collision zone. The multi-disciplinary Tien Shan - Pamir Geodynamic Program (TIPAGE) was designed to address some of the geodynamic key questions in this region. A magnetotelluric (MT) survey was carried out in concert with other geophysical and geological observations in Kyrgyzstan and Tajikistan, predominantly along a 350 km long and 50 km wide corridor from southern Tajikistan to Osh in Kyrgyzstan across the Pamir Plateau and southern Tien Shan mountain ranges. In total we recorded MT data at 178 stations, 26 of them combine long-period and broad band recordings. We present and compare 2D and 3D MT inversion results. Strike analysis of the data revealed an overall mean geo-electric strike direction consistent with the predominant tectonic trends. 2D inversion yields a reasonable data fit, with exception of some sites which exhibit phases above 90 degrees. 3D inversion was carried out with the ModEM package. We inverted for all four impedance tensor components and the vertical magnetic transfer functions. Topography was also included. The 3D models are generally in agreement with the 2D results but achieve a better data fit, particularly phases which could not be
3D magnetotelluric inversion with full distortion matrix
NASA Astrophysics Data System (ADS)
Gribenko, A. V.; Zhdanov, M. S.
2014-12-01
Distortion of regional electric fields by local structures represent one of the major problems facing three-dimensional magnetotelluric (MT) interpretation. Effect of 3D local inhomogenities on MT data can be described by a real 2x2 distortion matrix. In this project we develop a method of simultaneous inversion of the full MT impedance data for 3D conductivity distribution and for the distortion matrix. Tikhonov regularization is employed to solve the resulting inverse problem. Integral equations method is used to compute MT responses. Minimization of the cost functional is achieved via conjugate gradient method. The inversion algorithm is tested on the synthetic data from Dublin Secret Model II (DSM 2) for which multiple inversion solutions are available for comparison. Inclusion of the distortion matrix provides faster convergence and allows coarser discretization of the near-surface while achievingsimilar or better data fits as inversion for the conductivity only with finely discretized shallow regions. As a field data example we chose a subset of the EarthScope MT dataset covering Great Basin and adjacent areas of the Western United States. Great Basin data inversion identified several prominent conductive zones which correlate well with areas of tectonic and geothermal activity.
High resolution 3D nonlinear integrated inversion
NASA Astrophysics Data System (ADS)
Li, Yong; Wang, Xuben; Li, Zhirong; Li, Qiong; Li, Zhengwen
2009-06-01
The high resolution 3D nonlinear integrated inversion method is based on nonlinear theory. Under layer control, the log data from several wells (or all wells) in the study area and seismic trace data adjacent to the wells are input to a network with multiple inputs and outputs and are integratedly trained to obtain an adaptive weight function of the entire study area. Integrated nonlinear mapping relationships are built and updated by the lateral and vertical geologic variations of the reservoirs. Therefore, the inversion process and its inversion results can be constrained and controlled and a stable seismic inversion section with high resolution with velocity inversion, impedance inversion, and density inversion sections, can be gained. Good geologic effects have been obtained in model computation tests and real data processing, which verified that this method has high precision, good practicality, and can be used for quantitative reservoir analysis.
3D Electromagnetic inversion using conjugate gradients
Newman, G.A.; Alumbaugh, D.L.
1997-06-01
In large scale 3D EM inverse problems it may not be possible to directly invert a full least-squares system matrix involving model sensitivity elements. Thus iterative methods must be employed. For the inverse problem, we favor either a linear or non-linear (NL) CG scheme, depending on the application. In a NL CG scheme, the gradient of the objective function is required at each relaxation step along with a univariate line search needed to determine the optimum model update. Solution examples based on both approaches will be presented.
3D stochastic inversion of magnetic data
NASA Astrophysics Data System (ADS)
Shamsipour, Pejman; Chouteau, Michel; Marcotte, Denis
2011-04-01
A stochastic inversion method based on a geostatistical approach is presented to recover 3D susceptibility models from magnetic data. The aim of applying geostatistics is to provide quantitative descriptions of natural variables distributed in space or in time and space. Cokriging, the method which is used in this paper, is a method of estimation that minimizes the theoretical estimation error variance by using auto- and cross-correlations of several variables. The covariances for total field, susceptibility and total field-susceptibility are estimated using the observed data. Then, the susceptibility is cokriged or simulated as the primary variable. In order to avoid the natural tendency of the estimated structure to lay near the surface, depth weighting is included in the cokriging system. The algorithm assumes there is no remanent magnetization and the observation data represent only induced magnetization effects. The method is applied on different synthetic models to demonstrate its suitability for 3D inversion of magnetic data. A case study using ground measurements of total field at the Perseverance mine (Quebec, Canada) is presented. The recovered 3D susceptibility model provides beneficial information that can be used to analyze the geology of massive sulfide for the domain under study.
3D geophysical inversion for contact surfaces
NASA Astrophysics Data System (ADS)
Lelièvre, Peter; Farquharson, Colin
2014-05-01
Geologists' interpretations about the Earth typically involve distinct rock units with contacts (interfaces) between them. In contrast, standard minimum-structure volumetric inversions (performed on meshes of space-filling cells) recover smooth models inconsistent with such interpretations. There are several approaches through which geophysical inversion can help recover models with the desired characteristics. Some authors have developed iterative strategies in which several volumetric inversions are performed with regularization parameters changing to achieve sharper interfaces at automatically determined locations. Another approach is to redesign the regularization to be consistent with the desired model characteristics, e.g. L1-like norms or compactness measures. A few researchers have taken approaches that limit the recovered values to lie within particular ranges, resulting in sharp discontinuities; these include binary inversion, level set methods and clustering strategies. In most of the approaches mentioned above, the model parameterization considers the physical properties in each of the many space-filling cells within the volume of interest. The exception are level set methods, in which a higher dimensional function is parameterized and the contact surface is determined from the zero-level of that function. However, even level-set methods rely on an underlying volumetric mesh. We are researching a fundamentally different type of inversion that parameterizes the Earth in terms of the contact surfaces between rock units. 3D geological Earth models typically comprise wireframe surfaces of tessellated triangles or other polygonal planar facets. This wireframe representation allows for flexible and efficient generation of complicated geological structures. Therefore, a natural approach for representing a geophysical model in an inversion is to parameterize the wireframe contact surfaces as the coordinates of the nodes (facet vertices). The geological and
Sensitivity of an MT Array to 3D Structure Outside the Array Footprint
NASA Astrophysics Data System (ADS)
Booker, J. R.; Mackie, R. L.; Burd, A. I.; Pomposiello, M. C.; Favetto, A. B.
2015-12-01
Standard data collection strategy in magnetotellurics (MT) is to deploy a profile or array of sites that spans the target of interest. There is no expectation that structure can be imaged outside the area covered by sites. We have inverted two MT arrays for 3D structure under Argentina. The two arrays do not overlap, but serendipitously the 3D model for the northern array overlaps the position of a prominent 3D deep conductive structure seen in the inversion of the southern array. To our surprise this deep southern feature is also imaged by the northern array even though it is well outside the footprint of the northern array. It therefore appears that typical intuition about one's ability to image structure outside the span of the sites is not always true. We present model studies to demonstrate why this is so and under what conditions one can expect a 3D array to be capable of imaging structure outside the array.
NASA Astrophysics Data System (ADS)
Beka, Thomas I.; Smirnov, Maxim; Birkelund, Yngve; Senger, Kim; Bergh, Steffen G.
2016-08-01
Broadband (0.001-1000 s) magnetotelluric (MT) data along a crooked profile collected to investigate the geothermal potential on Spitsbergen could not be fully explained by two-dimensional (2D) models; hence we interpret the data with three-dimensional (3D) inversion herein. To better accommodate 3D features and nearby off profile resistivity structures, the full MT impedance tensor data together with the tipper were inverted. As a model control, a detailed bathymetry is systematically incorporated in the inversion. Our results from testing different inversion settings emphasised that appropriately choosing and tuning the starting model, data error floor and the model regularization together are crucial to obtain optimum benefit from MT field data. Through the 3D inversion, we reproduced out of quadrant impedance components and obtained an overall satisfactory data fit (RMS = 1.05). The final 3D resistivity model displays a complex geology of the near surface region (< 1.5 km), which suggests fractures, localized and regional fault systems and igneous intrusions in the Mesozoic platform cover deposits. The Billefjorden fault zone is revealed as a consistent and deep rooted (> 2 km) conductive anomaly, confirming the regional nature of the fault. The fault zone is positioned between two uplifted basement blocks (> 1000 Ωm) of presumably pre-Devonian (Caledonian) metamorphic rocks, and the fault may have been responsible for deformation in the overlying Paleozoic-Mesozoic unit. Upper crustal conductive anomalies (< 10 Ωm) below the Paleozoic-Mesozoic succession in the western part of the 3D model are interpreted as part of a Devonian basin fill. These conductors are laterally and vertically bounded by resistive rocks, suggesting a conducive environment for deep geothermal heat storage. Having this scenario in an area of a known high heat-flow, deep faults and a thinned lithosphere makes the hypothesis on finding a technologically exploitable geothermal resource
On the Inverse Problem of Binocular 3D Motion Perception
Lages, Martin; Heron, Suzanne
2010-01-01
It is shown that existing processing schemes of 3D motion perception such as interocular velocity difference, changing disparity over time, as well as joint encoding of motion and disparity, do not offer a general solution to the inverse optics problem of local binocular 3D motion. Instead we suggest that local velocity constraints in combination with binocular disparity and other depth cues provide a more flexible framework for the solution of the inverse problem. In the context of the aperture problem we derive predictions from two plausible default strategies: (1) the vector normal prefers slow motion in 3D whereas (2) the cyclopean average is based on slow motion in 2D. Predicting perceived motion directions for ambiguous line motion provides an opportunity to distinguish between these strategies of 3D motion processing. Our theoretical results suggest that velocity constraints and disparity from feature tracking are needed to solve the inverse problem of 3D motion perception. It seems plausible that motion and disparity input is processed in parallel and integrated late in the visual processing hierarchy. PMID:21124957
3D stochastic geophysical inversion for contact surface geometry
NASA Astrophysics Data System (ADS)
Lelièvre, Peter; Farquharson, Colin; Bijani, Rodrigo
2015-04-01
Geologists' interpretations about the Earth typically involve distinct rock units with contacts (interfaces) between them. As such, 3D geological Earth models typically comprise wireframe contact surfaces of tessellated triangles or other polygonal planar facets. In contrast, standard minimum-structure geophysical inversions are performed on meshes of space-filling cells (typically prisms or tetrahedra) and recover smoothly varying physical property distributions that are inconsistent with typical geological interpretations. There are several approaches through which mesh-based geophysical inversion can help recover models with some of the desired characteristics. However, a more effective strategy is to consider a fundamentally different type of inversion that works directly with models that comprise surfaces representing contacts between rock units. We are researching such an approach, our goal being to perform geophysical forward and inverse modelling directly with 3D geological models of any complexity. Geological and geophysical models should be specified using the same parameterization such that they are, in essence, the same Earth model. We parameterize the wireframe contact surfaces in a 3D model as the coordinates of the nodes (facet vertices). The physical properties of each rock unit in a model remain fixed while the geophysical inversion controls the position of the contact surfaces via the control nodes, perturbing the surfaces as required to fit the geophysical data responses. This is essentially a "geometry inversion", which can be used to recover the unknown geometry of a target body or to investigate the viability of a proposed Earth model. We apply global optimization strategies to solve the inverse problem, including stochastic sampling to obtain statistical information regarding the likelihood of particular features in the model, helping to assess the viability of a proposed model. Jointly inverting multiple types of geophysical data is simple
NASA Astrophysics Data System (ADS)
Garcia Juanatey, M. A.; Hübert, J.; Tryggvason, A.; Juhlin, C.; Pedersen, L. B.; Bauer, T. E.; Dehghannejad, M.
2012-12-01
Broadband MT data were acquired in the Skellefte district, an important mining area in northern Sweden, as part of the VINNOVA project "4D modeling of the Skellefte District". The project aims to provide a better understanding of the local and regional processes that took place in the past and, thus, provide a framework for new exploration strategies to target deeper deposits in the area. The new MT data, acquired in the central part of the district, consist of 36 stations along two parallel profiles that follow seismic reflection lines and potential field modeling studies in the area. The dimensionality and quality of the data set were carefully analyzed and 2D and 3D inversions were performed. 2D inversions provided a basis to compare with other MT surveys in the area and to some extent validate 3D inversion results. 3D inversion was deemed necessary given the complexity of the geological setting of the studied area. The algorithms used were the data space based REBOCC and WSINV3DMT methods. For the 2D inversion only the determinant of the impedance tensor was used, while for the 3D inversion all its elements were considered. Prior to 3D inversion, new error floors were calculated using individual 1D inversions of the off-diagonal components of the impedance tensor. The obtained models have an RMS value of ~2, and share the main regional features. A detailed comparison reveals the superiority of the 3D model, both in model structures and data fit. An interpretation of the 3D model is presented using also results from previous geophysical studies. The most interesting features in the model are conductors associated to prominent shear zones (from 1 to 12 km deep) and hydrothermally altered zones within the Skellefte Group rocks (between 250 and 6000 m depth). In addition, it is possible to identify faults associated to the transport of hydrothermal fluids that might be closely related to ore forming processes.
Direct inversion of digital 3D Fraunhofer holography maps
NASA Astrophysics Data System (ADS)
Podorov, Sergei G.; Förster, Eckhart
2016-01-01
The Differential Fourier Holography (DFH) gives an exact mathematical solution of the inverse problem of diffraction in the Fraunhofer regime. After the first publication [1] the Differential Fourier Holography was successfully applied in many experiments to obtain amplitude and phase information about two-dimensional (2D) images. In this article we demonstrate numerically the possibility to apply the DFH also for investigation of unknown 3D Objects. The first simulation is made for a double-spiral structure plus a line as a reference object.
3D magnetic inversion by planting anomalous densities
NASA Astrophysics Data System (ADS)
Uieda, L.; Barbosa, V. C.
2013-05-01
We present a new 3D magnetic inversion algorithm based on the computationally efficient method of planting anomalous densities. The algorithm consists of an iterative growth of the anomalous bodies around prismatic elements called "seeds". These seeds are user-specified and have known magnetizations. Thus, the seeds provide a way for the interpreter to specify the desired skeleton of the anomalous bodies. The inversion algorithm is computationally efficient due to various optimizations made possible by the iterative nature of the growth process. The control provided by the use of seeds allows one to test different hypothesis about the geometry and magnetization of targeted anomalous bodies. To demonstrate this capability, we applied our inversion method to the Morro do Engenho (ME) and A2 magnetic anomalies, central Brazil (Figure 1a). ME is an outcropping alkaline intrusion formed by dunites, peridotites and pyroxenites with known magnetization. A2 is a magnetic anomaly to the Northeast of ME and is thought to be a similar intrusion that is not outcropping. Therefore, a plausible hypothesis is that A2 has the same magnetization as ME. We tested this hypothesis by performing an inversion using a single seed for each body. Both seeds had the same magnetization. Figure 1b shows that the inversion produced residuals up to 2000 nT over A2 (i.e., a poor fit) and less than 400 nT over ME (i.e., an acceptable fit). Figure 1c shows that ME is a compact outcropping body with bottom at approximately 5 km, which is in agreement with previous interpretations. However, the estimate produced by the inversion for A2 is outcropping and is not compact. In summary, the estimate for A2 provides a poor fit to the observations and is not in accordance with the geologic information. This leads to the conclusion that A2 does not have the same magnetization as ME. These results indicate the usefulness and capabilities of the inversion method here proposed.; a) total field magnetic anomaly
NASA Astrophysics Data System (ADS)
Usui, Yoshiya
2015-08-01
A 3-D magnetotelluric (MT) inversion code using unstructured tetrahedral elements has been developed in order to correct the topographic effect by directly incorporating it into computational grids. The electromagnetic field and response functions get distorted at the observation sites of MT surveys because of the undulating surface topography, and without correcting this distortion, the subsurface structure can be misinterpreted. Of the two methods proposed to correct the topographic effect, the method incorporating topography explicitly in the inversion is applicable to a wider range of surveys. For forward problems, it has been shown that the finite element method using unstructured tetrahedral elements is useful for the incorporation of topography. Therefore, this paper shows the applicability of unstructured tetrahedral elements in MT inversion using the newly developed code. The inversion code is capable of using the impedance tensor, the vertical magnetic transfer function (VMTF), and the phase tensor as observational data, and it estimates the subsurface resistivity values and the distortion tensor of each observation site. The forward part of the code was verified using two test models, one incorporating topographic effect and one without, and the verifications showed that the results were almost the same as those of previous works. The developed inversion code was then applied to synthetic data from a MT survey, and was verified as being able to recover the resistivity structure as well as other inversion codes. Finally, to confirm its applicability to the data affected by topography, inversion was performed using the synthetic data of the model that included two overlapping mountains. In each of the cases using the impedance tensor, the VMTF and the phase tensor, by including the topography in the mesh, the subsurface resistivity was determined more proficiently than in the case using the flat-surface mesh. Although the locations of the anomalies were
Inverse Tomo-Lithography for Making Microscopic 3D Parts
NASA Technical Reports Server (NTRS)
White, Victor; Wiberg, Dean
2003-01-01
According to a proposal, basic x-ray lithography would be extended to incorporate a technique, called inverse tomography, that would enable the fabrication of microscopic three-dimensional (3D) objects. The proposed inverse tomo-lithographic process would make it possible to produce complex shaped, submillimeter-sized parts that would be difficult or impossible to make in any other way. Examples of such shapes or parts include tapered helices, paraboloids with axes of different lengths, and even Archimedean screws that could serve as rotors in microturbines. The proposed inverse tomo-lithographic process would be based partly on a prior microfabrication process known by the German acronym LIGA (lithographie, galvanoformung, abformung, which means lithography, electroforming, molding). In LIGA, one generates a precise, high-aspect ratio pattern by exposing a thick, x-ray-sensitive resist material to an x-ray beam through a mask that contains the pattern. One can electrodeposit metal into the developed resist pattern to form a precise metal part, then dissolve the resist to free the metal. Aspect ratios of 100:1 and patterns into resist thicknesses of several millimeters are possible.
New Advances for a joint 3D inversion of multiple EM methods
NASA Astrophysics Data System (ADS)
Meqbel, N. M.; Ritter, O.
2013-12-01
Electromagnetic (EM) methods are routinely applied to image the subsurface from shallow to regional structures. Individual EM methods differ in their sensitivities towards resistive and conductive structures as well as in their exploration depths. Joint 3D inversion of multiple EM data sets can result in significantly better resolution of subsurface structures than the individual inversions. Proper weighting between different EM data is essential, however. We present a recently developed weighting algorithm to combine magnetotelluric (MT), controlled source EM (CSEM) and DC-geoelectric (DC) data. It is well known that MT data are mostly sensible to regional conductive structures, whereas, CSEM and DC data are more suitable to recover more shallow and resistive structures. Our new scheme is based on weighting individual components of the total data gradient after each model update. Norms of each data residual are used to assess how much weight individual components of the total data gradient must have to achieve an equal contribution of all data sets in the inverse model. A numerically efficient way to search for appropriate weighting factors could be established by applying a bi-diagonalization procedure to the sensitivity matrix. Thereby, the original inverse problem can be projected onto a smaller dimension in which the search of weighting factors is numerically cheap. We demonstrate the efficiency of the proposed weighting schemes and explore the model domain with synthetic data sets.
Novel accurate and scalable 3-D MT forward solver based on a contracting integral equation method
NASA Astrophysics Data System (ADS)
Kruglyakov, M.; Geraskin, A.; Kuvshinov, A.
2016-11-01
We present a novel, open source 3-D MT forward solver based on a method of integral equations (IE) with contracting kernel. Special attention in the solver is paid to accurate calculations of Green's functions and their integrals which are cornerstones of any IE solution. The solver supports massive parallelization and is able to deal with highly detailed and contrasting models. We report results of a 3-D numerical experiment aimed at analyzing the accuracy and scalability of the code.
Inverse rendering of faces with a 3D morphable model.
Aldrian, Oswald; Smith, William A P
2013-05-01
In this paper, we present a complete framework to inverse render faces with a 3D Morphable Model (3DMM). By decomposing the image formation process into geometric and photometric parts, we are able to state the problem as a multilinear system which can be solved accurately and efficiently. As we treat each contribution as independent, the objective function is convex in the parameters and a global solution is guaranteed. We start by recovering 3D shape using a novel algorithm which incorporates generalization error of the model obtained from empirical measurements. We then describe two methods to recover facial texture, diffuse lighting, specular reflectance, and camera properties from a single image. The methods make increasingly weak assumptions and can be solved in a linear fashion. We evaluate our findings on a publicly available database, where we are able to outperform an existing state-of-the-art algorithm. We demonstrate the usability of the recovered parameters in a recognition experiment conducted on the CMU-PIE database. PMID:23520253
Solution accelerators for large scale 3D electromagnetic inverse problems
Newman, Gregory A.; Boggs, Paul T.
2004-04-05
We provide a framework for preconditioning nonlinear 3D electromagnetic inverse scattering problems using nonlinear conjugate gradient (NLCG) and limited memory (LM) quasi-Newton methods. Key to our approach is the use of an approximate adjoint method that allows for an economical approximation of the Hessian that is updated at each inversion iteration. Using this approximate Hessian as a preconditoner, we show that the preconditioned NLCG iteration converges significantly faster than the non-preconditioned iteration, as well as converging to a data misfit level below that observed for the non-preconditioned method. Similar conclusions are also observed for the LM iteration; preconditioned with the approximate Hessian, the LM iteration converges faster than the non-preconditioned version. At this time, however, we see little difference between the convergence performance of the preconditioned LM scheme and the preconditioned NLCG scheme. A possible reason for this outcome is the behavior of the line search within the LM iteration. It was anticipated that, near convergence, a step size of one would be approached, but what was observed, instead, were step lengths that were nowhere near one. We provide some insights into the reasons for this behavior and suggest further research that may improve the performance of the LM methods.
NASA Astrophysics Data System (ADS)
Miensopust, Marion P.; Queralt, Pilar; Jones, Alan G.; 3D MT modellers
2013-06-01
Over the last half decade the need for, and importance of, three-dimensional (3-D) modelling of magnetotelluric (MT) data have increased dramatically and various 3-D forward and inversion codes are in use and some have become commonly available. Comparison of forward responses and inversion results is an important step for code testing and validation prior to `production' use. The various codes use different mathematical approximations to the problem (finite differences, finite elements or integral equations), various orientations of the coordinate system, different sign conventions for the time dependence and various inversion strategies. Additionally, the obtained results are dependent on data analysis, selection and correction as well as on the chosen mesh, inversion parameters and regularization adopted, and therefore, a careful and knowledge-based use of the codes is essential. In 2008 and 2011, during two workshops at the Dublin Institute for Advanced Studies over 40 people from academia (scientists and students) and industry from around the world met to discuss 3-D MT inversion. These workshops brought together a mix of code writers as well as code users to assess the current status of 3-D modelling, to compare the results of different codes, and to discuss and think about future improvements and new aims in 3-D modelling. To test the numerical forward solutions, two 3-D models were designed to compare the responses obtained by different codes and/or users. Furthermore, inversion results of these two data sets and two additional data sets obtained from unknown models (secret models) were also compared. In this manuscript the test models and data sets are described (supplementary files are available) and comparisons of the results are shown. Details regarding the used data, forward and inversion parameters as well as computational power are summarized for each case, and the main discussion points of the workshops are reviewed. In general, the responses
NASA Astrophysics Data System (ADS)
Dong, H.; Kun, Z.; Zhang, L.
2015-12-01
This magnetotelluric (MT) system contains static shift correction and 3D inversion. The correction method is based on the data study on 3D forward modeling and field test. The static shift can be detected by the quantitative analysis of apparent parameters (apparent resistivity and impedance phase) of MT in high frequency range, and completed correction with inversion. The method is an automatic processing technology of computer with zero-cost, and avoids the additional field work and indoor processing with good results shown in Figure 1a-e. Figure 1a shows a normal model (I) without any local heterogeneity. Figure 1b shows a static-shifted model (II) with two local heterogeneous bodies (10 and 1000 ohm.m). Figure 1c is the inversion result (A) for the synthetic data generated from model I. Figure 1d is the inversion result (B) for the static-shifted data generated from model II. Figure 1e is the inversion result (C) for the static-shifted data from model II, but with static shift correction. The results show that the correction method is useful. The 3D inversion algorithm is improved base on the NLCG method of Newman & Alumbaugh (2000) and Rodi & Mackie (2001). For the algorithm, we added the frequency based parallel structure, improved the computational efficiency, reduced the memory of computer, added the topographic and marine factors, and added the constraints of geology and geophysics. So the 3D inversion could even work in PAD with high efficiency and accuracy. The application example of theoretical assessment in oil and gas exploration is shown in Figure 1f-i. The synthetic geophysical model consists of five layers (from top to downwards): shale, limestone, gas, oil, groundwater and limestone overlying a basement rock. Figure 1f-g show the 3D model and central profile. Figure 1h shows the centrel section of 3D inversion, the resultsd show a high degree of reduction in difference on the synthetic model. Figure 1i shows the seismic waveform reflects the
NASA Astrophysics Data System (ADS)
Ullmann, A.; Scheunert, M.; Afanasjew, M.; Börner, R.-U.; Siemon, B.; Spitzer, K.
2016-07-01
As a standard procedure, multi-frequency helicopter-borne electromagnetic (HEM) data are inverted to conductivity-depth models using 1-D inversion methods, which may, however, fail in areas of strong lateral conductivity contrasts (so-called induction anomalies). Such areas require more realistic multi-dimensional modelling. Since the full 3-D inversion of an entire HEM data set is still extremely time consuming, our idea is to combine fast 1-D and accurate but numerically expensive 3-D inversion of HEM data in such a way that the full 3-D inversion is only carried out for those parts of a HEM survey which are affected by induction anomalies. For all other parts, a 1-D inversion method is sufficient. We present a newly developed algorithm for identification, selection, and extraction of induction anomalies in HEM data sets and show how the 3-D inversion model of the anomalous area is re-integrated into the quasi-1-D background. Our proposed method is demonstrated to work properly on a synthetic and a field HEM data set from the Cuxhaven tunnel valley in Germany. We show that our 1-D/3-D approach yields better results compared to 1-D inversions in areas where 3-D effects occur.
3D velocity structure of Mt. Fuji and the south Fossa Magna, Japan
NASA Astrophysics Data System (ADS)
Nakamichi, H.
2005-12-01
We present models of the velocity structure beneath the south Fossa Magna and Mt. Fuji, Japan, using local earthquake tomography and new data from a dense seismic network. The seismic network includes 28 temporary and 138 permanent 3-component seismic stations. The stations are deployed 2 - 10 km apart with a gradual increase in station spacing away from Mt. Fuji and are also densely distributed in the direction NE-SW across Mt. Fuji. We inverted 63,287 P- and 59,558 S-wave arrival times from 1087 local earthquakes to obtain the 3D P- (Vp) and S-wave velocity (Vs) and their ratio (Vp/Vs) structure. There is a high correlation between the Vp and Vs structures. At 5-15 km depths both velocity structures show low velocity anomalies trending northward in the west along the Fujikawa river, from Suruga Bay to northwest of Mt. Fuji. North of the Izu Peninsula, there is a broad high-velocity zone. These results correlate with Bouguer gravity anomalies previously observed. A shallowing high velocity anomaly is seen above sea level beneath Mt. Fuji. A low-Vp, Vs and Vp/Vs (1.5-1.6) anomaly is seen at depths of 7 - 17 km beneath Mt. Fuji, corresponding to locations of low-frequency (LF) earthquakes. Volatile fluids (CO2-H2O) could be abundant in the low Vp/Vs region and play an important role in generating the LF earthquakes. A low-Vp, Vs and high-Vp/Vs (1.8-1.9) anomaly is seen at depths of 15 - 25 km beneath Mt. Fuji and is interpreted as partial melt (basaltic magma). P-wave velocities of 6.0 - 6.5 km/s in the Izu collision zone beneath the Tanzawa Mountains indicate a plutonic body of tonalite within an accreted crustal slice of the Philippine Sea plate.
3 D gravity inversion based on SL0 norm
NASA Astrophysics Data System (ADS)
Meng, Zhaohai; Xu, Xuechun; Zheng, Changqing
2015-04-01
The inversion of three-dimensional geophysical properties (density, magnetic susceptibility, electrical resistivity) has occupies very important position in geophysical interpretation for geophysical interpreters, combining with the corresponding geological data, it will produce a very good solution to solve the corresponding geological problems, especially, in the separate abnormal body of ore bodies .the method would have produce much more good results. There are mainly three kinds of mainstream geophysical inversion methods in the now geophysical inversion method : 1. The minimum model method, 2. the most gentle model method, 3. The smoothest model. The main solution is the optimal solution by solving mixed set equations to solve the corresponding inverse problem, the main difference of the three methods is the differences of the weighting function mode, and in essence, it is to find the best solution based on regularization principle, finally, the reaction of the convergence are obtained. The methods are based on the minimum volume, such as compression inversion and focusing inversion. The two methods also can get much more clearer and sharper boundaries. This abstract choose of the inversion method is based on the theory of minimum volume method. The selection of weighted function can effectively reduce the inversion of the number of iterations and accelerate the rate of inversion. it can conform to the requirements of the current large-scale airborne gravity. Without reducing the quality of the inversion, at the same time, it can accelerate the rate of inversion. The inversion can get the sharp boundary, spatial location, and density attributes of the abnormal body. it needs the quality of the computer performance and geophysical data. Therefore it requests to reduce the random and random noise as far as possible. According to a lot of model tests, It proves that the choice of the weighting function can get very good inversion result. In the inversion
3D inversion based on multi-grid approach of magnetotelluric data from Northern Scandinavia
NASA Astrophysics Data System (ADS)
Cherevatova, M.; Smirnov, M.; Korja, T. J.; Egbert, G. D.
2012-12-01
In this work we investigate the geoelectrical structure of the cratonic margin of Fennoscandian Shield by means of magnetotelluric (MT) measurements carried out in Northern Norway and Sweden during summer 2011-2012. The project Magnetotellurics in the Scandes (MaSca) focuses on the investigation of the crust, upper mantle and lithospheric structure in a transition zone from a stable Precambrian cratonic interior to a passive continental margin beneath the Caledonian Orogen and the Scandes Mountains in western Fennoscandia. Recent MT profiles in the central and southern Scandes indicated a large contrast in resistivity between Caledonides and Precambrian basement. The alum shales as a highly conductive layers between the resistive Precambrian basement and the overlying Caledonian nappes are revealed from this profiles. Additional measurements in the Northern Scandes were required. All together data from 60 synchronous long period (LMT) and about 200 broad band (BMT) sites were acquired. The array stretches from Lofoten and Bodo (Norway) in the west to Kiruna and Skeleftea (Sweden) in the east covering an area of 500x500 square kilometers. LMT sites were occupied for about two months, while most of the BMT sites were measured during one day. We have used new multi-grid approach for 3D electromagnetic (EM) inversion and modelling. Our approach is based on the OcTree discretization where the spatial domain is represented by rectangular cells, each of which might be subdivided (recursively) into eight sub-cells. In this simplified implementation the grid is refined only in the horizontal direction, uniformly in each vertical layer. Using multi-grid we manage to have a high grid resolution near the surface (for instance, to tackle with galvanic distortions) and lower resolution at greater depth as the EM fields decay in the Earth according to the diffusion equation. We also have a benefit in computational costs as number of unknowns decrease. The multi-grid forward
Quasi MT Inversion of Short-Offset Transient Electromagnetic Data
NASA Astrophysics Data System (ADS)
Chen, Wei-ying; Xue, Guo-qiang; Khan, Muhammad Younis
2016-07-01
The short-offset transient electromagnetic method (SOTEM) has been extensively used for mineral and hydrocarbon exploration and hydrogeological investigations due to its ease of use and capability to generate diagnostic subsurface information. At present, the data processing methods of SOTEM are mainly focused on one dimensional inversion. To apply the proven inversion methods of frequency domain electromagnetic methods to SOTEM data, this paper presents a new transformation relation from time to frequency based on the similarity between SOTEM all-time apparent resistivity and magnetotelluric (MT) apparent resistivity. Results show that the transformation coefficients depend on the variation trend of SOTEM all-time apparent resistivity curves. Bostick inversion and conjugate gradient inversion techniques were applied to transformed SOTEM data and the results were validated by some simulated calculations and field measured data. This study provides a novel method to SOTEM data processing and a useful aid to join inversion with MT data.
3D Strucutural Geological Model of the Alpi Mt. Area (Southern Italy)
NASA Astrophysics Data System (ADS)
La Bruna, Vincenzo; Lamarche, Juliette; Viseur, Sophie; Agosta, Fabrizio; Prosser, Giacomo
2016-04-01
The study area is located in the inner portion of the southern Apennines fold-and-thrust belt. The Alpi Mt. is the only portion of the Apulian domain cropping in this sector. In fact, it is considered as a structural analogue of the Val d'Agri and Tempa Rossa reservoirs (Basilicata). The Alpi Mt. tectonic unit is composed of two main cronostratigraphic intervals, represented by a 2000m-thick Mesozoic carbonate succession and a Messinian mixed carbonate-terrigenous succession. The Messinian interval is made up of a Lower Messinian sedimentary cycle, wich form a paraconformity with the underlying Mesozoic carbonates, and an Upper Messinian cycle characterized by a marked unconformity at the bottom. This study aims to better understand the role exerted by the precontractional tectonic structures during the Messinian interval, wich are responsible for the development of the sedimentary angular unconformity. To reach this goal, a 3D structural geological model was build up by using the Gocad(R) software. The construction of the 3D model was gained through the integration of several results related to geological field mapping, well log analysis and seismic reflection data. Focusing on the Upper Messinian sedimentary horizon, in order to achieve the true geometry and kinematics of the high-angle extensional faults that bound the sedimentary depocenters, the model was restored through vertical line methodology. This process allows to obtain more information about location, geometry, and sedimentary depocenter orientations. Furthermore, the 3D structural model brings some important results from the 3D fault analysis that are represented by attitude, geometry and dimensional parameters of the fault network that affect the study area.
3D stochastic inversion and joint inversion of potential fields for multi scale parameters
NASA Astrophysics Data System (ADS)
Shamsipour, Pejman
In this thesis we present the development of new techniques for the interpretation of potential field (gravity and magnetic data), which are the most widespread economic geophysical methods used for oil and mineral exploration. These new techniques help to address the long-standing issue with the interpretation of potential fields, namely the intrinsic non-uniqueness inversion of these types of data. The thesis takes the form of three papers (four including Appendix), which have been published, or soon to be published, in respected international journals. The purpose of the thesis is to introduce new methods based on 3D stochastical approaches for: 1) Inversion of potential field data (magnetic), 2) Multiscale Inversion using surface and borehole data and 3) Joint inversion of geophysical potential field data. We first present a stochastic inversion method based on a geostatistical approach to recover 3D susceptibility models from magnetic data. The aim of applying geostatistics is to provide quantitative descriptions of natural variables distributed in space or in time and space. We evaluate the uncertainty on the parameter model by using geostatistical unconditional simulations. The realizations are post-conditioned by cokriging to observation data. In order to avoid the natural tendency of the estimated structure to lay near the surface, depth weighting is included in the cokriging system. Then, we introduce algorithm for multiscale inversion, the presented algorithm has the capability of inverting data on multiple supports. The method involves four main steps: i. upscaling of borehole parameters (It could be density or susceptibility) to block parameters, ii. selection of block to use as constraints based on a threshold on kriging variance, iii. inversion of observation data with selected block densities as constraints, and iv. downscaling of inverted parameters to small prisms. Two modes of application are presented: estimation and simulation. Finally, a novel
Flow-Through Stream Modeling with MODFLOW and MT3D: Certainties and Limitations.
Ben Simon, Rose; Bernard, Stéphane; Meurville, Charles; Rebour, Vincent
2015-01-01
This paper aims to assess MODFLOW and MT3D capabilities for simulating the spread of contaminants from a river exhibiting an unusual relationship with an alluvial aquifer, with the groundwater head higher than the river head on one side and lower on the other (flow-through stream). A series of simulation tests is conducted using a simple hypothetical model so as to characterize and quantify these limitations. Simulation results show that the expected contaminant spread could be achieved with a specific configuration composed of two sets of parameters: (1) modeled object parameters (hydraulic groundwater gradient, hydraulic conductivity values of aquifer and streambed), and (2) modeling parameters (vertical discretization of aquifer, horizontal refinement of stream modeled with River [RIV] package). The influence of these various parameters on simulation results is investigated, and potential complications and errors are identified. Contaminant spread from stream to aquifer is not always reproduced by MT3D due to the RIV package's inability to simulate lateral exchange fluxes between stream and aquifer. This paper identifies the need for a MODFLOW streamflow package allowing lateral stream-aquifer interactions and streamflow routine calculations. Such developments could be of particular interest for modeling contaminated flow-through streams.
New 3D parallel SGILD modeling and inversion
Xie, G.; Li, J.; Majer, E.
1998-09-01
In this paper, a new parallel modeling and inversion algorithm using a Stochastic Global Integral and Local Differential equation (SGILD) is presented. The authors derived new acoustic integral equations and differential equation for statistical moments of the parameters and field. The new statistical moments integral equation on the boundary and local differential equations in domain will be used together to obtain mean wave field and its moments in the modeling. The new moments global Jacobian volume integral equation and the local Jacobian differential equations in domain will be used together to update the mean parameters and their moments in the inversion. A new parallel multiple hierarchy substructure direct algorithm or direct-iteration hybrid algorithm will be used to solve the sparse matrices and one smaller full matrix from domain to the boundary, in parallel. The SGILD modeling and imaging algorithm has many advantages over the conventional imaging approaches. The SGILD algorithm can be used for the stochastic acoustic, electromagnetic, and flow modeling and inversion, and are important for the prediction of oil, gas, coal, and geothermal energy reservoirs in geophysical exploration.
NASA Astrophysics Data System (ADS)
Miller, Craig A.; Williams-Jones, Glyn
2016-06-01
A new 3D geophysical model of the Mt Tongariro Volcanic Massif (TgVM), New Zealand, provides a high resolution view of the volcano's internal structure and hydrothermal system, from which we derive implications for volcanic hazards. Geologically constrained 3D inversions of potential field data provides a greater level of insight into the volcanic structure than is possible from unconstrained models. A complex region of gravity highs and lows (± 6 mGal) is set within a broader, ~ 20 mGal gravity low. A magnetic high (1300 nT) is associated with Mt Ngauruhoe, while a substantial, thick, demagnetised area occurs to the north, coincident with a gravity low and interpreted as representing the hydrothermal system. The hydrothermal system is constrained to the west by major faults, interpreted as an impermeable barrier to fluid migration and extends to basement depth. These faults are considered low probability areas for future eruption sites, as there is little to indicate they have acted as magmatic pathways. Where the hydrothermal system coincides with steep topographic slopes, an increased likelihood of landslides is present and the newly delineated hydrothermal system maps the area most likely to have phreatic eruptions. Such eruptions, while small on a global scale, are important hazards at the TgVM as it is a popular hiking area with hundreds of visitors per day in close proximity to eruption sites. The model shows that the volume of volcanic material erupted over the lifespan of the TgVM is five to six times greater than previous estimates, suggesting a higher rate of magma supply, in line with global rates of andesite production. We suggest that our model of physical property distribution can be used to provide constraints for other models of dynamic geophysical processes occurring at the TgVM.
Direct inversion of digital 3D Fraunhofer holography maps.
Podorov, Sergei G; Förster, Eckhart
2016-01-20
Differential Fourier holography (DFH) gives an exact mathematical solution of the inverse problem of diffraction in the Fraunhofer regime. After the first publication [Opt. Express15, 9954 (2007)], DFH was successfully applied in many experiments to obtain amplitude and phase information about two-dimensional images. In this paper, we demonstrate numerically the possibility to apply DFH also for investigation of unknown three-dimensional objects. The first simulation is made for a double-spiral structure plus a line as a reference object.
NASA Astrophysics Data System (ADS)
Portal, Angélie; Fargier, Yannick; Lénat, Jean-François; Labazuy, Philippe
2016-04-01
The electrical resistivity tomography (ERT) method, initially developed for environmental and engineering exploration, is now commonly used for geological structures imaging. Such structures can present complex characteristics that conventional 2D inversion processes cannot perfectly integrate. Here we present a new 3D inversion algorithm named EResI, firstly developed for levee investigation, and presently applied to the study of a complex lava dome (the Puy de Dôme volcano, France). EResI algorithm is based on a conventional regularized Gauss-Newton inversion scheme and a 3D non-structured discretization of the model (double grid method based on tetrahedrons). This discretization allows to accurately model the topography of investigated structure (without a mesh deformation procedure) and also permits a precise location of the electrodes. Moreover, we demonstrate that a complete 3D unstructured discretization limits the number of inversion cells and is better adapted to the resolution capacity of tomography than a structured discretization. This study shows that a 3D inversion with a non-structured parametrization has some advantages compared to classical 2D inversions. The first advantage comes from the fact that a 2D inversion leads to artefacts due to 3D effects (3D topography, 3D internal resistivity). The second advantage comes from the fact that the capacity to experimentally align electrodes along an axis (for 2D surveys) depends on the constrains on the field (topography...). In this case, a 2D assumption induced by 2.5D inversion software prevents its capacity to model electrodes outside this axis leading to artefacts in the inversion result. The last limitation comes from the use of mesh deformation techniques used to accurately model the topography in 2D softwares. This technique used for structured discretization (Res2dinv) is prohibed for strong topography (>60 %) and leads to a small computational errors. A wide geophysical survey was carried out
Rodriguez, Brian D.; Sweetkind, Donald S.
2015-01-01
The 3-D inversion was generally able to reproduce the gross resistivity structure of the “known” model, but the simulated conductive volcanic composite unit horizons were often too shallow when compared to the “known” model. Additionally, the chosen computation parameters such as station spacing appear to have resulted in computational artifacts that are difficult to interpret but could potentially be removed with further refinements of the 3-D resistivity inversion modeling technique.
Levander, Alan R.
2004-12-01
Under ER63662, 3-D Seismic Experimentation and Advanced Processing/Inversion Development for Investigations of the Shallow Subsurface, we have completed a number of subprojects associated with the Hill Air Force Base (HAFB) high resolution 3-D reflection/tomography dataset.
Reduced Scan Time 3D FLAIR using Modulated Inversion and Repetition Time
Gai, Neville D.; Butman, John A.
2014-01-01
Purpose To design and evaluate a new reduced scan time 3D FLuid Attenuated Inversion Recovery (FLAIR) sequence. Materials and Methods The 3D FLAIR sequence was modified so that the repetition time was modulated in a predetermined smooth fashion (3D mFLAIR). Inversion times were adjusted accordingly to maintain CSF suppression. Simulations were performed to determine SNR for gray matter (GM), white matter (WM) and CSF. Fourteen volunteers were imaged using the modified and product sequence. SNR measurements were performed in GM, WM and CSF. Mean value and the 95% confidence interval ([CI]) were assessed. Scan time for the 3D FLAIR and 3D mFLAIR sequences was measured. Results There was no statistically significant difference in the SNR measured in GM (P value = 0.5; mean SNR = 42.8 [CI]: 38.2-45.5 vs 42.2 [CI]: 38.3-46.1 for 3D FLAIR and 3D mFLAIR, respectively) and WM (P value = 0.25; mean SNR = 32.1 [CI]: 30.3-33.8 vs 32.9 [CI]: 31.1-34.7). Scan time reduction greater than 30% was achieved for the given parameter set with the 3D mFLAIR sequence. Conclusion Scan time for 3D FLAIR can be effectively reduced by modulating repetition and inversion time in a predetermined fashion while maintaining the SNR and CNR of a constant TR sequence. PMID:24979311
NASA Astrophysics Data System (ADS)
Fadel, I.; van der Meijde, M.; Kerle, N.
2013-12-01
Non-uniqueness of satellite gravity interpretation has been usually reduced by using a priori information from various sources, e.g. seismic tomography models. The reduction in non-uniqueness has been based on velocity-density conversion formulas or user interpretation for 3D subsurface structures (objects) in seismic tomography models. However, these processes introduce additional uncertainty through the conversion relations due to the dependency on the other physical parameters such as temperature and pressure, or through the bias in the interpretation due to user choices and experience. In this research, a new methodology is introduced to extract the 3D subsurface structures from 3D geophysical data using a state-of-art 3D Object Oriented Image Analysis (OOA) technique. 3D OOA is tested using a set of synthetic models that simulate the real situation in the study area of this research. Then, 3D OOA is used to extract 3D subsurface objects from a real 3D seismic tomography model. The extracted 3D objects are used to reconstruct a forward model and its response is compared with the measured satellite gravity. Finally, the result of the forward modelling, based on the extracted 3D objects, is used to constrain the inversion process of satellite gravity data. Through this work, a new object-based approach is introduced to interpret and extract the 3D subsurface objects from 3D geophysical data. This can be used to constrain modelling and inversion of potential field data using the extracted 3D subsurface structures from other methods. In summary, a new approach is introduced to constrain inversion of satellite gravity measurements and enhance interpretation capabilities.
NASA Astrophysics Data System (ADS)
Rezaie, Mohammad; Moradzadeh, Ali; Kalate, Ali Nejati; Aghajani, Hamid
2016-09-01
Inversion of gravity data is one of the important steps in the interpretation of practical data. One of the most interesting geological frameworks for gravity data inversion is the detection of sharp boundaries between orebody and host rocks. The focusing inversion is able to reconstruct a sharp image of the geological target. This technique can be efficiently applied for the quantitative interpretation of gravity data. In this study, a new reweighted regularized method for the 3D focusing inversion technique based on Lanczos bidiagonalization method is developed. The inversion results of synthetic data show that the new method is faster than common reweighted regularized conjugate gradient method to produce an acceptable solution for focusing inverse problem. The new developed inversion scheme is also applied for inversion of the gravity data collected over the San Nicolas Cu-Zn orebody in Zacatecas State, Mexico. The inversion results indicate a remarkable correlation with the true structure of the orebody that is achieved from drilling data.
A research of 3D gravity inversion based on the recovery of sparse underdetermined linear equations
NASA Astrophysics Data System (ADS)
Zhaohai, M.
2014-12-01
Because of the properties of gravity data, it is made difficult to solve the problem of multiple solutions. There are two main types of 3D gravity inversion methods：One of two methods is based on the improvement of the instability of the sensitive matrix, solving the problem of multiple solutions and instability in 3D gravity inversion. Another is to join weight function into the 3D gravity inversion iteration. Through constant iteration, it can renewal density values and weight function to achieve the purpose to solve the multiple solutions and instability of the 3D gravity data inversion. Thanks to the sparse nature of the solutions of 3D gravity data inversions, we can transform it into a sparse equation. Then, through solving the sparse equations, we can get perfect 3D gravity inversion results. The main principle is based on zero norm of sparse matrix solution of the equation. Zero norm is mainly to solve the nonzero solution of the sparse matrix. However, the method of this article adopted is same as the principle of zero norm. But the method is the opposite of zero norm to obtain zero value solution. Through the form of a Gaussian fitting solution of the zero norm, we can find the solution by using regularization principle. Moreover, this method has been proved that it had a certain resistance to random noise in the mathematics, and it was more suitable than zero norm for the solution of the geophysical data. 3D gravity which is adopted in this article can well identify abnormal body density distribution characteristics, and it can also recognize the space position of abnormal distribution very well. We can take advantage of the density of the upper and lower limit penalty function to make each rectangular residual density within a reasonable range. Finally, this 3D gravity inversion is applied to a variety of combination model test, such as a single straight three-dimensional model, the adjacent straight three-dimensional model and Y three
3-D MT modelling and HMT analysis for the north-west part of Poland
NASA Astrophysics Data System (ADS)
Ślęzak, Katarzyna; Brasse, Heinrich; Jóźwiak, Waldemar; Nowożyński, Krzysztof
2014-05-01
The area covered by magnetotelluric survey is a part of the Trans-European Suture Zone (TESZ). The TESZ is the largest tectonic boundary in Europe, extending from the British Isles through Poland to the Black Sea. Several two-dimensional (2-D) models of the electrical resistivity distribution have already been constructed for this area but it turned out that the region had a complicated, three-dimensional structure. Thus a three-dimensional (3-D) inversion model appears to be relevant and interesting to investigate. In cooperation with the Berlin Magnetotelluric Work Group several additional long-period magnetotelluric (LMT) sites were assembled in 2012 and 2013. The mesh was located in the north-west part of Poland (Pomerania region). As a result we obtained 17 new sites over the surface area of approximately of 100 km × 50 km, in addition to 9 stations set up earlier. The collected data were converted to a uniform format and the initial processing was executed. By using the latest software the transfer functions (impedances) and the ellipses of the phase tensor for the sites of our mesh have been calculated. The apparent resistivities and phase responses as functions of period are calculated from the impedance components. The computer program ModEM (Egbert G.D., Kelbert A., 2012), which is used for this work, is a parallel 3-D inversion program for magnetotelluric data. The inversion code employs MPI and, besides impedances, includes tippers and magnetic tensor. The main result of this work is a 3-D model with a good RMS fit of ~2.2 which we could compare with previous outcomes. In this model two prominent, NW-SE striking conductive lineaments located in the mid-crustal levels are noticed. These structures we relate tentatively to the Variscan and Caledonian deformation fronts. Also the analysis of the invariants of the Horizontal Magnetic Tensor (HMT) obtained from previous results (Jozwiak, 2012) allowed us to examine the TESZ in more detail.
A fast and low-loss 3-D magnetotelluric inversion method with parallel structure
NASA Astrophysics Data System (ADS)
Zhang, K.; Zhang, L.
2013-12-01
The 2D assumption is valid in some cases of interpretation, the approximation does not work in most cases, especially in areas with complex geo-electrical structure. A number of 3D magentotelluric inversion methods has been proposed, including RRI, CG, QA, NLCG. Each of those methods has its own advantages and disadvantages. However, as the 3D dataset and mesh grid require greater computer memory and calculation time than 2D methods, the efficiency of the inversion scheme become a key concern of 3D inversions. We chose NLCG as the optimization method for inversion. A parameter matrix related with the current resisitivity model and data error is proposed to approximate the Hessian matrix. So four forward calculation can be avoided each iteration. In addition, OPENMP parallel API is utilized to establish an effecient parallel inversion structure based on frequency to reduce computation time. And both synthetic and field data are used to test the efficiency of the inversion and the preconditioning method. The model consists of four square prisms residing in a halfspace. The total computation time of invertion is 706s (use one PC). Fiugre 1 shows the inversion result. The abnormal bodies can be distinguished clearly. Field data from the NIHE dataset in China is used to verify the reliability and efficiency of the 3D inversion method. The total computation time is about 25 minutes after 60 iterations on one PC. Totally, four electrical layers can be corresponded to the four stratum in 3D AMT inversion model, and the faults can be seen clearly. In addition, we can get more information about fault and alteration interface from constrained inversion result. Finally, the inversion method is very fast and low-loss, so it can be used in modern PC (need only one PC) with few hardware constraints. (a): initial model; (b): inversion depth slices (1-4km); (c): fitting error (a): AMT 3D slice; (b): CSAMT 2D model; (c): TEM 1D model; (d): SIP 2D model; (e) AMT 3D constrained
Quasi-3D Waveform Inversion for Velocity Structures and Source Process Analyses Using its Results
NASA Astrophysics Data System (ADS)
Hikima, K.; Koketsu, K.
2007-12-01
In this study, we propose an efficient waveform inversion method for 2-D velocity structures and 3-D velocity structures are constructed by interpolating the results of the 2-D inversions. We apply these methods to a source process study of the 2003 Miyagi-ken Hokubu earthquake. We will first construct a velocity model, then determine the source processes of this earthquake sequence using the Green's function calculated with the resultant 3-D velocity model. We formulate the inversion procedure in a 2-D cross section. In a 2-D problem, an earthquake is forced to be a line source. Therefore, we introduce approximate transformation from a line source to a point source (Vidale and Helmberger, 1987). We use the 2-D velocity-stress staggered-grid finite difference scheme, so that the source representation is somewhat different from the original 'source box method' and we apply additional corrections to calculated waveforms. The boundary shapes of layers are expressed by connected nodes and we invert observed waveforms for layer thicknesses at the nodes. We perform 2-D velocity inversions along cross sections which involve a medium-size earthquake and observation points. We assemble the results for many stations and interpolated them to construct the 3-D velocity model. Finally, we calculate waveforms from the target earthquake by the 3-D finite difference method with this velocity model to confirm the validity of the model. We next perform waveform inversions for source processes of the 2003 Miyagi-ken Hokubu earthquake sequence using the resultant 3-D velocity model. We divide the fault plane into northern and southern subplanes, so that the southern subplane includes the hypocenter of the mainshock and the largest foreshock. The strike directions of the northern and southern subplanes were N-S and NE-SW, respectively. The Green's functions for these source inversions are calculated using the reciprocal theorem. We determine the slip models using the 3- D structure and
NASA Astrophysics Data System (ADS)
Simutė, S.; Fichtner, A.
2015-12-01
We present a feasibility study for seismic source inversions using a 3-D velocity model for the Japanese Islands. The approach involves numerically calculating 3-D Green's tensors, which is made efficient by exploiting Green's reciprocity. The rationale for 3-D seismic source inversion has several aspects. For structurally complex regions, such as the Japan area, it is necessary to account for 3-D Earth heterogeneities to prevent unknown structure polluting source solutions. In addition, earthquake source characterisation can serve as a means to delineate existing faults. Source parameters obtained for more realistic Earth models can then facilitate improvements in seismic tomography and early warning systems, which are particularly important for seismically active areas, such as Japan. We have created a database of numerically computed 3-D Green's reciprocals for a 40°× 40°× 600 km size area around the Japanese Archipelago for >150 broadband stations. For this we used a regional 3-D velocity model, recently obtained from full waveform inversion. The model includes attenuation and radial anisotropy and explains seismic waveform data for periods between 10 - 80 s generally well. The aim is to perform source inversions using the database of 3-D Green's tensors. As preliminary steps, we present initial concepts to address issues that are at the basis of our approach. We first investigate to which extent Green's reciprocity works in a discrete domain. Considering substantial amounts of computed Green's tensors we address storage requirements and file formatting. We discuss the importance of the initial source model, as an intelligent choice can substantially reduce the search volume. Possibilities to perform a Bayesian inversion and ways to move to finite source inversion are also explored.
3D Airborne Electromagnetic Inversion: A case study from the Musgrave Region, South Australia
NASA Astrophysics Data System (ADS)
Cox, L. H.; Wilson, G. A.; Zhdanov, M. S.; Sunwall, D. A.
2012-12-01
Geophysicists know and accept that geology is inherently 3D, and is resultant from complex, overlapping processes related to genesis, metamorphism, deformation, alteration, weathering, and/or hydrogeology. Yet, the geophysics community has long relied on qualitative analysis, conductivity depth imaging (CDIs), 1D inversion, and/or plate modeling. There are many reasons for this deficiency, not the least of which has been the lack of capacity for historic 3D AEM inversion algorithms to invert entire surveys so as to practically affect exploration decisions. Our recent introduction of a moving sensitivity domain (footprint) methodology has been a paradigm shift in AEM interpretation. The basis of this method is that one needs only to calculate the responses and sensitivities for that part of the 3D earth model that is within the AEM system's sensitivity domain (footprint), and then superimpose all sensitivity domains into a single, sparse sensitivity matrix for the entire 3D earth model which is then updated in a regularized inversion scheme. This has made it practical to rigorously invert entire surveys with thousands of line kilometers of AEM data to mega-cell 3D models in hours using multi-processor workstations. Since 2010, over eighty individual projects have been completed for Aerodat, AEROTEM, DIGHEM, GEOTEM, HELITEM, HoisTEM, MEGATEM, RepTEM, RESOLVE, SkyTEM, SPECTREM, TEMPEST, and VTEM data from Australia, Brazil, Canada, Finland, Ghana, Peru, Tanzania, the US, and Zambia. Examples of 3D AEM inversion have been published for a variety of applications, including mineral exploration, oil sands exploration, salinity, permafrost, and bathymetry mapping. In this paper, we present a comparison of 3D inversions for SkyTEM, SPECTREM, TEMPET and VTEM data acquired over the same area in the Musgrave region of South Australia for exploration under cover.
Lithologic identification & mapping test based on 3D inversion of magnetic and gravity
NASA Astrophysics Data System (ADS)
Yan, Jiayong; Lv, Qingtian; Qi, Guang; Zhao, Jinhua; Zhang, Yongqian
2016-04-01
Though lithologic identification & mapping to achieve ore concentration district transparent within 5km depth is the main way to realize deep fine structures study, to explore deep mineral resources and to reveal metallogenic regularity of large-scale ore district . Owing to the wide covered area, high sampling density and mature three-dimensional inversion algorithm of gravity and magnetic data, so gravity and magnetic inversion become the most likely way to achieve three-dimensional lithologic mapping at the present stage. In this paper, we take Lu-zong(Lujiang county to Zongyang county in Anhui province ,east China) ore district as a case, we proposed lithologic mapping flow based 3D inversion of gravity magnetic and then carry out the lithologic mapping test. Lithologic identification & mapping flow is as follows: 1. Analysis relations between lithology and density and magnetic susceptibility by cross plot. 2.Extracting appropriate residual anomalies from high-precision Bourger gravity and aeromagnetic. 3.Use same mesh, do 3D magnetic and gravity inversion respectively under prior information constrained, and then invert susceptibility and density 3D model. 4. According setp1, construct logical topology operations between density 3D model and susceptibility. 5.Use the logical operations, identify lithogies cell by cell in 3D mesh, and then get 3D lithological model. According this flow, we obtained three-dimensional distribution of five main type lithologies in the Lu-Zong ore district within 5km depth. The result of lithologic mapping not only showed that the shallow characteristics and surface geological mapping are basically Coincide,more importantly ,it reveals the deeper lithologic changes.The lithlogical model make up the insufficient of surface geological mapping. The lithologic mapping test results in Lu-Zong ore concentration district showed that lithological mapping using 3D inversion of gravity and magnetic is a effective method to reveal the
Laplace-domain waveform modeling and inversion for the 3D acoustic-elastic coupled media
NASA Astrophysics Data System (ADS)
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.
NASA Astrophysics Data System (ADS)
Gumilar, Irwan; Abidin, Hasanuddin Z.; Putra, Andreas D.; Haerani, Nia
2015-04-01
Indonesia is a country with many volcanoes. Each volcano in Indonesia typically has its own crater characteristics. One of them is the Mt.Talaga Bodas, located in Garut, West Java. Researches regarding the crater characteristics are necessary for volcanic disaster mitigation process. One of them is the modelling of the shape of the crater. One of the methods that can be used to model the volcanic crater is using Terrestrial Laser Scanner (TLS). This research aims to create a 3 dimensional (3D) model of the crater of the Mt. Talaga Bodas, that hopefully can be utilized for volcanic disaster mitigation. The methodology used in this research is by obtaining the scanning data using TLS and GPS measurements to obtain the coordinates of the reference points. The data processing methods consist of several steps, namely target to target registration, filterization, georeference, meshing point cloud, surface making, drawing, and 3D modelling. These steps were done using the Cyclone 7 software, and also using 3DS MAX for 3D modelling. The result of this data processing is a 3D model of the crater of the Mt. Talaga Bodas which is similar with the real shape. The calculation result shows that the height of the crater is 62.522 m, the diameter of the crater is 467.231 m, and the total area is 2961054.652 m2. The main obstacle in this research is the dense vegetation which becomes the noise and affects the crater model.
Research on Joint Parameter Inversion for an Integrated Underground Displacement 3D Measuring Sensor
Shentu, Nanying; Qiu, Guohua; Li, Qing; Tong, Renyuan; Shentu, Nankai; Wang, Yanjie
2015-01-01
Underground displacement monitoring is a key means to monitor and evaluate geological disasters and geotechnical projects. There exist few practical instruments able to monitor subsurface horizontal and vertical displacements simultaneously due to monitoring invisibility and complexity. A novel underground displacement 3D measuring sensor had been proposed in our previous studies, and great efforts have been taken in the basic theoretical research of underground displacement sensing and measuring characteristics by virtue of modeling, simulation and experiments. This paper presents an innovative underground displacement joint inversion method by mixing a specific forward modeling approach with an approximate optimization inversion procedure. It can realize a joint inversion of underground horizontal displacement and vertical displacement for the proposed 3D sensor. Comparative studies have been conducted between the measured and inversed parameters of underground horizontal and vertical displacements under a variety of experimental and inverse conditions. The results showed that when experimentally measured horizontal displacements and vertical displacements are both varied within 0 ~ 30 mm, horizontal displacement and vertical displacement inversion discrepancies are generally less than 3 mm and 1 mm, respectively, under three kinds of simulated underground displacement monitoring circumstances. This implies that our proposed underground displacement joint inversion method is robust and efficient to predict the measuring values of underground horizontal and vertical displacements for the proposed sensor. PMID:25871714
Shentu, Nanying; Qiu, Guohua; Li, Qing; Tong, Renyuan; Shentu, Nankai; Wang, Yanjie
2015-01-01
Underground displacement monitoring is a key means to monitor and evaluate geological disasters and geotechnical projects. There exist few practical instruments able to monitor subsurface horizontal and vertical displacements simultaneously due to monitoring invisibility and complexity. A novel underground displacement 3D measuring sensor had been proposed in our previous studies, and great efforts have been taken in the basic theoretical research of underground displacement sensing and measuring characteristics by virtue of modeling, simulation and experiments. This paper presents an innovative underground displacement joint inversion method by mixing a specific forward modeling approach with an approximate optimization inversion procedure. It can realize a joint inversion of underground horizontal displacement and vertical displacement for the proposed 3D sensor. Comparative studies have been conducted between the measured and inversed parameters of underground horizontal and vertical displacements under a variety of experimental and inverse conditions. The results showed that when experimentally measured horizontal displacements and vertical displacements are both varied within 0~30 mm, horizontal displacement and vertical displacement inversion discrepancies are generally less than 3 mm and 1 mm, respectively, under three kinds of simulated underground displacement monitoring circumstances. This implies that our proposed underground displacement joint inversion method is robust and efficient to predict the measuring values of underground horizontal and vertical displacements for the proposed sensor. PMID:25871714
NASA Astrophysics Data System (ADS)
Bean, C. J.; O'Brien, G.; de Barros, L.; Murphy, S.; Lokmer, I.; Saccorotti, G.; Patane, D.; Metaxian, J.
2009-05-01
Recent field observation and laboratory experiments have demonstrated a broad range of deformation mechanisms in volcanic rocks, and a juxtaposition of brittle and ductile deformation in both space and time. On the other hand seismological observations of transient deformation at volcanoes yield an equally wide variety of signal types including Volcano Tectonic (VT), Long Period (LP), Very Long Period (VLP) and tremor. A clear goal is to find robust connections between these independent sets of observations, linking detailed field studies, well controlled laboratory experiments and volcano seismology. In volcano seismology VT events are usually interpreted as the brittle response of the edifice to stressing whereas LP and VLP events are thought to result from fluid-filled conduit dynamics. However, strong wave propagation path effects and a large number of possible source mechanisms make it difficult to find a quantitative interpretation of mechanism/rheology. Numerical simulations have a key role to play in making the connection between well-controlled laboratory experiments and the field. Furthermore, many of the features seen in real volcano seismograms can be reproduced in 3D full wavefield simulations of both wet (coupled multi phase fluids and solids) and dry (rupture propagation) models. Even in simulated data the underlying rheology/source mechanisms are difficult to determine from an inversion of the synthetic seismograms, especially for sparse data with poor velocity control. With this in mind a detailed field experiment was undertaken on Mt Etna in June 2008, comprising 30+ stations in the summit area. Aided by simulated data in realistic velocity models, this has given us an unprecedented picture of shallow LP activity on Etna. These high resolution observations will be compared with recent results from laboratory experiments and with numerical simulations in an effort to better constrain the rheology/mechanism of the sources.
NASA Astrophysics Data System (ADS)
Rosas-Carbajal, M.; Linde, N.; Peacock, J.; Zyserman, F. I.; Kalscheuer, T.; Thiel, S.
2015-12-01
Surface-based monitoring of mass transfer caused by injections and extractions in deep boreholes is crucial to maximize oil, gas and geothermal production. Inductive electromagnetic methods, such as magnetotellurics, are appealing for these applications due to their large penetration depths and sensitivity to changes in fluid conductivity and fracture connectivity. In this work, we propose a 3-D Markov chain Monte Carlo inversion of time-lapse magnetotelluric data to image mass transfer following a saline fluid injection. The inversion estimates the posterior probability density function of the resulting plume, and thereby quantifies model uncertainty. To decrease computation times, we base the parametrization on a reduced Legendre moment decomposition of the plume. A synthetic test shows that our methodology is effective when the electrical resistivity structure prior to the injection is well known. The centre of mass and spread of the plume are well retrieved. We then apply our inversion strategy to an injection experiment in an enhanced geothermal system at Paralana, South Australia, and compare it to a 3-D deterministic time-lapse inversion. The latter retrieves resistivity changes that are more shallow than the actual injection interval, whereas the probabilistic inversion retrieves plumes that are located at the correct depths and oriented in a preferential north-south direction. To explain the time-lapse data, the inversion requires unrealistically large resistivity changes with respect to the base model. We suggest that this is partly explained by unaccounted subsurface heterogeneities in the base model from which time-lapse changes are inferred.
Fast 3D inversion of airborne gravity-gradiometry data using Lanczos bidiagonalization method
NASA Astrophysics Data System (ADS)
Meng, Zhaohai; Li, Fengting; Zhang, Dailei; Xu, Xuechun; Huang, Danian
2016-09-01
We developed a new fast inversion method for to process and interpret airborne gravity gradiometry data, which was based on Lanczos bidiagonalization algorithm. Here, we describe the application of this new 3D gravity gradiometry inversion method to recover a subsurface density distribution model from the airborne measured gravity gradiometry anomalies. For this purpose, the survey area is divided into a large number of rectangular cells with each cell possessing a constant unknown density. It is well known that the solution of large linear gravity gradiometry is an ill-posed problem since using the smoothest inversion method is considerably time consuming. We demonstrate that the Lanczos bidiagonalization method can be an appropriate algorithm to solve a Tikhonov solver time cost function for resolving the large equations within a short time. Lanczos bidiagonalization is designed to make the very large gravity gradiometry forward modeling matrices to become low-rank, which will considerably reduce the running time of the inversion method. We also use a weighted generalized cross validation method to choose the appropriate Tikhonov parameter to improve inversion results. The inversion incorporates a model norm that allows us to attain the smoothing and depth of the solution; in addition, the model norm counteracts the natural decay of the kernels, which concentrate at shallow depths. The method is applied on noise-contaminated synthetic gravity gradiometry data to demonstrate its suitability for large 3D gravity gradiometry data inversion. The airborne gravity gradiometry data from the Vinton Salt Dome, USE, were considered as a case study. The validity of the new method on real data is discussed with reference to the Vinton Dome inversion result. The intermediate density values in the constructed model coincide well with previous results and geological information. This demonstrates the validity of the gravity gradiometry inversion method.
Finite-Source Inversion for the 2004 Parkfield Earthquake using 3D Velocity Model Green's Functions
NASA Astrophysics Data System (ADS)
Kim, A.; Dreger, D.; Larsen, S.
2008-12-01
We determine finite fault models of the 2004 Parkfield earthquake using 3D Green's functions. Because of the dense station coverage and detailed 3D velocity structure model in this region, this earthquake provides an excellent opportunity to examine how the 3D velocity structure affects the finite fault inverse solutions. Various studies (e.g. Michaels and Eberhart-Phillips, 1991; Thurber et al., 2006) indicate that there is a pronounced velocity contrast across the San Andreas Fault along the Parkfield segment. Also the fault zone at Parkfield is wide as evidenced by mapped surface faults and where surface slip and creep occurred in the 1966 and the 2004 Parkfield earthquakes. For high resolution images of the rupture process"Ait is necessary to include the accurate 3D velocity structure for the finite source inversion. Liu and Aurchuleta (2004) performed finite fault inversions using both 1D and 3D Green's functions for 1989 Loma Prieta earthquake using the same source paramerization and data but different Green's functions and found that the models were quite different. This indicates that the choice of the velocity model significantly affects the waveform modeling at near-fault stations. In this study, we used the P-wave velocity model developed by Thurber et al (2006) to construct the 3D Green's functions. P-wave speeds are converted to S-wave speeds and density using by the empirical relationships of Brocher (2005). Using a finite difference method, E3D (Larsen and Schultz, 1995), we computed the 3D Green's functions numerically by inserting body forces at each station. Using reciprocity, these Green's functions are recombined to represent the ground motion at each station due to the slip on the fault plane. First we modeled the waveforms of small earthquakes to validate the 3D velocity model and the reciprocity of the Green"fs function. In the numerical tests we found that the 3D velocity model predicted the individual phases well at frequencies lower than 0
NASA Astrophysics Data System (ADS)
Bell, R. E.; Morgan, J. V.; Warner, M.
2013-12-01
Our understanding of subduction margin seismogenesis has been revolutionised in the last couple of decades with the discovery that the size of the seismogenic zone may not be controlled simply by temperature and a broad spectrum of seismic behaviour exists from stick-slip to stable sliding. Laboratory and numerical experiments suggest that physical properties, particularly fluid pressure may play an important role in controlling the seismic behaviour of subduction margins. Although drilling can provide information on physical properties along subduction thrust faults at point locations at relatively shallow depths, correlations between physical properties and seismic velocity using rock physics relationships are required to resolve physical properties along the margin and down-dip. Therefore, high resolution seismic velocity models are key to recovering physical property information at subduction plate boundaries away from drill sites. 3D Full waveform inversion (FWI) is a technique pioneered by the oil industry to obtain high-resolution high-fidelity models of physical properties in the sub-surface. 3D FWI involves the inversion of low-frequency (>2 to <7 Hz), early arriving (principally transmitted) seismic data, to recover the macro (intermediate to long-wavelength) velocity structure. Although 2D FWI has been used to improve velocity models of subduction plate boundaries before, 3D FWI has not yet been attempted. 3D inversions have superior convergence and accuracy, as they sample the subsurface with multi-azimuth multiply-crossing wavefields. In this contribution we perform a suite of synthetic tests to investigate if 3D FWI could be used to better resolve physical property information along subduction margin plate boundaries using conventionally collected 3D seismic data. We base our analysis on the Muroto Basin area of the Nankai margin and investigate if the acquisition parameters and geometry of the subduction margin render 3D seismic data collected across
NASA Astrophysics Data System (ADS)
Liu, B.; Li, S. C.; Nie, L. C.; Wang, J.; L, X.; Zhang, Q. S.
2012-12-01
Traditional inversion method is the most commonly used procedure for three-dimensional (3D) resistivity inversion, which usually takes the linearization of the problem and accomplish it by iterations. However, its accuracy is often dependent on the initial model, which can make the inversion trapped in local optima, even cause a bad result. Non-linear method is a feasible way to eliminate the dependence on the initial model. However, for large problems such as 3D resistivity inversion with inversion parameters exceeding a thousand, main challenges of non-linear method are premature and quite low search efficiency. To deal with these problems, we present an improved Genetic Algorithm (GA) method. In the improved GA method, smooth constraint and inequality constraint are both applied on the object function, by which the degree of non-uniqueness and ill-conditioning is decreased. Some measures are adopted from others by reference to maintain the diversity and stability of GA, e.g. real-coded method, and the adaptive adjustment of crossover and mutation probabilities. Then a generation method of approximately uniform initial population is proposed in this paper, with which uniformly distributed initial generation can be produced and the dependence on initial model can be eliminated. Further, a mutation direction control method is presented based on the joint algorithm, in which the linearization method is embedded in GA. The update vector produced by linearization method is used as mutation increment to maintain a better search direction compared with the traditional GA with non-controlled mutation operation. By this method, the mutation direction is optimized and the search efficiency is improved greatly. The performance of improved GA is evaluated by comparing with traditional inversion results in synthetic example or with drilling columnar sections in practical example. The synthetic and practical examples illustrate that with the improved GA method we can eliminate
The interpretation of magnetic anomalies by 3D inversion: A case study from Central Iran
NASA Astrophysics Data System (ADS)
Tavakoli, M.; Nejati Kalateh, A.; Ghomi, S.
2016-03-01
The thick sedimentary units in Central Iran contain structures that form oil traps and are underlain by a basaltic layer which is amenable for study using its magnetic susceptibility. The study and modeling of such sedimentary structures provide valuable exploratory information. In this study, we locate and interpret an underground magnetic susceptibility interface using 3D non-linear inverse modeling of magnetic data to make a better judgment in the context of hydrocarbon existence. The 3D structure is reconstructed by making it equal to a number of side by side rectangular hexahedrons or prisms and calculating their thicknesses such that the bottoms of the prisms are corresponding to the magnetic susceptibility interface. By one of the most important mathematical tool in computational science, Taylor series, the non-linear problem changes to a linear problem near to initial model. In many inverse problems, we often need to invert large size matrices. To find the inverse of these matrices we use Singular Value Decomposition (SVD) method. The algorithm by an iterative method comparing model response with actual data will modify the initial guess of model parameters. The efficiency of the method and subprograms, programmed in MATLAB, has been shown by inverse modeling of free noise and noise-contaminated synthetic data. Finally, we inverted magnetic field data from Garmsar area in Central Iran which the results were acceptable.
NASA Astrophysics Data System (ADS)
Cubuk-Sabuncu, Yesim; Taymaz, Tuncay; Fichtner, Andreas
2016-04-01
We present a 3D radially anisotropic velocity model of the crust and uppermost mantle structure beneath the Sea of Marmara and surroundings based on the full waveform inversion method. The intense seismic activity and crustal deformation are observed in the Northwest Turkey due to transition tectonics between the strike-slip North Anatolian Fault (NAF) and the extensional Aegean region. We have selected and simulated complete waveforms of 62 earthquakes (Mw > 4.0) occurred during 2007-2015, and recorded at (Δ < 10°) distances. Three component earthquake data is obtained from broadband seismic stations of Kandilli Observatory and Earthquake Research Center (KOERI, Turkey), Hellenic Unified Seismic Network (HUSN, Greece) and Earthquake Research Center of Turkey (AFAD-DAD). The spectral-element solver of the wave equation, SES3D algorithm, is used to simulate seismic wave propagation in 3D spherical coordinates (Fichtner, 2009). The Large Scale Seismic Inversion Framework (LASIF) workflow tool is also used to perform full seismic waveform inversion (Krischer et al., 2015). The initial 3D Earth model is implemented from the multi-scale seismic tomography study of Fichtner et al. (2013). Discrepancies between the observed and simulated synthetic waveforms are determined using the time-frequency misfits which allows a separation between phase and amplitude information (Fichtner et al., 2008). The conjugate gradient optimization method is used to iteratively update the initial Earth model when minimizing the misfit. The inversion is terminated after 19 iterations since no further advances are observed in updated models. Our analysis revealed shear wave velocity variations of the shallow and deeper crustal structure beneath western Turkey down to depths of ~35-40 km. Low shear wave velocity anomalies are observed in the upper and mid crustal depths beneath major fault zones located in the study region. Low velocity zones also tend to mark the outline of young volcanic
Kılıç, Emre Eibert, Thomas F.
2015-05-01
An approach combining boundary integral and finite element methods is introduced for the solution of three-dimensional inverse electromagnetic medium scattering problems. Based on the equivalence principle, unknown equivalent electric and magnetic surface current densities on a closed surface are utilized to decompose the inverse medium problem into two parts: a linear radiation problem and a nonlinear cavity problem. The first problem is formulated by a boundary integral equation, the computational burden of which is reduced by employing the multilevel fast multipole method (MLFMM). Reconstructed Cauchy data on the surface allows the utilization of the Lorentz reciprocity and the Poynting's theorems. Exploiting these theorems, the noise level and an initial guess are estimated for the cavity problem. Moreover, it is possible to determine whether the material is lossy or not. In the second problem, the estimated surface currents form inhomogeneous boundary conditions of the cavity problem. The cavity problem is formulated by the finite element technique and solved iteratively by the Gauss–Newton method to reconstruct the properties of the object. Regularization for both the first and the second problems is achieved by a Krylov subspace method. The proposed method is tested against both synthetic and experimental data and promising reconstruction results are obtained.
Simultaneous elastic parameter inversion in 2-D/3-D TTI medium combined later arrival times
NASA Astrophysics Data System (ADS)
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.
3-D full waveform inversion of seismic data; Part I. Theory
Lee, Ki Ha
2003-05-12
Full waveform inversion of seismic data is a challenging subject partly because of the lack of precise knowledge of the source. Since currently available approaches involve some form of approximations to the source, inversion results are subject to the quality and the choice of the source information used. A new full waveform inversion scheme has been introduced (Lee and Kim, 2003) using normalized wavefield for simple two-dimensional (2-D) scalar problems. The method does not require source information, so potential inversion errors due to source estimation may be eliminated. A gather of seismic traces is first Fourier-transformed into the frequency domain and a normalized wavefield is obtained for each trace in the frequency domain. Normalization is done with respect to the frequency response of a reference trace selected from the gather, so the complex-valued normalized wavefield is source-independent and dimensionless. The inversion algorithm minimizes misfits between measured normalized wavefield and numerically computed normalized wavefield. In this paper the full waveform inversion is extended to three-dimensional (3-D) problems.
3D Inversion of complex resistivity data: Case study on Mineral Exploration Site.
NASA Astrophysics Data System (ADS)
Son, Jeong-Sul; Kim, Jung-ho; Park, Sam-gyu; Park, My-Kyung
2016-04-01
Complex resistivity (CR) method is a frequency domain induced polarization (IP) method. It is also known as Spectral IP (SIP) method, if wider frequencies are used in data acquisition and interpretation. Although it takes more times than conventional time domain IP method, its data quality is more stable because its data acquisition which measures amplitude and phase is done when the source current is being injected. Our research group has been studying the modeling and inversion algorithms of complex resistivity (CR) method since several years ago and recently applied developed algorithms to various real field application. Due to tough terrain in our country, Profile survey and 2D interpretation were generally used. But to get more precise interpretation, three dimensional modeling and inversion algorithm is required. We developed three dimensional inversion algorithm for this purpose. In the inversion, we adopt the method of adaptive lagraingian multiplier which is automatically set based on the size of error misfit and model regularization norm. It was applied on the real data acquired for mineral exploration sites. CR data was acquired with the Zeta system, manufactured by Zonge Co. In the inversion, only the lower frequency data is used considering its quality and developed 3D inversion algorithm was applied to the acquired data set. Its results were compared to those of time domain IP data conducted at the same site. Resistivity image sections of CR and conventional resistivity method were almost identical. Phase anomalies were well matched with chargeability anomalies and the mining history of the test site. Each anomalies were well discriminated in 3D interpretation than those of 2D. From those experiments, we know that CR method was very effective for the mineral exploration.
Integrated gravity and gravity gradient 3D inversion using the non-linear conjugate gradient
NASA Astrophysics Data System (ADS)
Qin, Pengbo; Huang, Danian; Yuan, Yuan; Geng, Meixia; Liu, Jie
2016-03-01
Gravity data, which are critical in mineral, oil, and gas exploration, are obtained from the vertical component of the gravity field, while gravity gradient data are measured from changes in the gravity field in three directions. However, few studies have sought to improve exploration techniques by integrating gravity and gravity gradient data using inversion methods. In this study, we developed a new method to integrate gravity and gravity gradient data in a 3D density inversion using the non-linear conjugate gradient (NLCG) method and the minimum gradient support (MGS) functional to regularize the 3D inverse problem and to obtain a clear and accurate image of the anomalous body. The NLCG algorithm, which is suitable for solving large-scale nonlinear optimization problems and requires no memory storage, was compared to the Broyden-Fletcher-Goldfarb-Shanno (BFGS) quasi-Newton algorithm and the results indicated that the convergence rate of NLCG is slower, but that the storage requirement and computation time is lower. To counteract the decay in kernel function, we introduced a depth weighting function for anomalous bodies at the same depth, with information about anomalous body depth obtained from well log and seismic exploration data. For anomalous bodies at different depths, we introduced a spatial gradient weighting function to incorporate additional information obtained in the inversion. We concluded that the spatial gradient weighting function enhanced the spatial resolution of the recovered model. Furthermore, our results showed that including multiple components for inversion increased the resolution of the recovered model. We validated our model by applying our inversion method to survey data from Vinton salt dome, Louisiana, USA. The results showed good agreement with known geologic information; thus confirming the accuracy of this approach.
Rosas-Carbajal, Marina; Linde, Nicolas; Peacock, Jared R.; Zyserman, F. I.; Kalscheuer, Thomas; Thiel, Stephan
2015-01-01
Surface-based monitoring of mass transfer caused by injections and extractions in deep boreholes is crucial to maximize oil, gas and geothermal production. Inductive electromagnetic methods, such as magnetotellurics, are appealing for these applications due to their large penetration depths and sensitivity to changes in fluid conductivity and fracture connectivity. In this work, we propose a 3-D Markov chain Monte Carlo inversion of time-lapse magnetotelluric data to image mass transfer following a saline fluid injection. The inversion estimates the posterior probability density function of the resulting plume, and thereby quantifies model uncertainty. To decrease computation times, we base the parametrization on a reduced Legendre moment decomposition of the plume. A synthetic test shows that our methodology is effective when the electrical resistivity structure prior to the injection is well known. The centre of mass and spread of the plume are well retrieved.We then apply our inversion strategy to an injection experiment in an enhanced geothermal system at Paralana, South Australia, and compare it to a 3-D deterministic time-lapse inversion. The latter retrieves resistivity changes that are more shallow than the actual injection interval, whereas the probabilistic inversion retrieves plumes that are located at the correct depths and oriented in a preferential north-south direction. To explain the time-lapse data, the inversion requires unrealistically large resistivity changes with respect to the base model. We suggest that this is partly explained by unaccounted subsurface heterogeneities in the base model from which time-lapse changes are inferred.
Earthquake source tensor inversion with the gCAP method and 3D Green's functions
NASA Astrophysics Data System (ADS)
Zheng, J.; Ben-Zion, Y.; Zhu, L.; Ross, Z.
2013-12-01
We develop and apply a method to invert earthquake seismograms for source properties using a general tensor representation and 3D Green's functions. The method employs (i) a general representation of earthquake potency/moment tensors with double couple (DC), compensated linear vector dipole (CLVD), and isotropic (ISO) components, and (ii) a corresponding generalized CAP (gCap) scheme where the continuous wave trains are broken into Pnl and surface waves (Zhu & Ben-Zion, 2013). For comparison, we also use the waveform inversion method of Zheng & Chen (2012) and Ammon et al. (1998). Sets of 3D Green's functions are calculated on a grid of 1 km3 using the 3-D community velocity model CVM-4 (Kohler et al. 2003). A bootstrap technique is adopted to establish robustness of the inversion results using the gCap method (Ross & Ben-Zion, 2013). Synthetic tests with 1-D and 3-D waveform calculations show that the source tensor inversion procedure is reasonably reliable and robust. As initial application, the method is used to investigate source properties of the March 11, 2013, Mw=4.7 earthquake on the San Jacinto fault using recordings of ~45 stations up to ~0.2Hz. Both the best fitting and most probable solutions include ISO component of ~1% and CLVD component of ~0%. The obtained ISO component, while small, is found to be a non-negligible positive value that can have significant implications for the physics of the failure process. Work on using higher frequency data for this and other earthquakes is in progress.
3D Laplace-domain full waveform inversion using a single GPU card
NASA Astrophysics Data System (ADS)
Shin, Jungkyun; Ha, Wansoo; Jun, Hyunggu; Min, Dong-Joo; Shin, Changsoo
2014-06-01
The Laplace-domain full waveform inversion is an efficient long-wavelength velocity estimation method for seismic datasets lacking low-frequency components. However, to invert a 3D velocity model, a large cluster of CPU cores have commonly been required to overcome the extremely long computing time caused by a large impedance matrix and a number of source positions. In this study, a workstation with a single GPU card (NVIDIA GTX 580) is successfully used for the 3D Laplace-domain full waveform inversion rather than a large cluster of CPU cores. To exploit a GPU for our inversion algorithm, the routine for the iterative matrix solver is ported to the CUDA programming language for forward and backward modeling parts with minimized modification of the remaining parts, which were originally written in Fortran 90. Using a uniformly structured grid set, nonzero values in the sparse impedance matrix can be arranged according to certain rules, which efficiently parallelize the preconditioned conjugate gradient method for a number of threads contained in the GPU card. We perform a numerical experiment to verify the accuracy of a floating point operation performed by a GPU to calculate the Laplace-domain wavefield. We also measure the efficiencies of the original CPU and modified GPU programs using a cluster of CPU cores and a workstation with a GPU card, respectively. Through the analysis, the parallelized inversion code for a GPU achieves the speedup of 14.7-24.6x compared to a CPU-based serial code depending on the degrees of freedom of the impedance matrix. Finally, the practicality of the proposed algorithm is examined by inverting a 3D long-wavelength velocity model using wide azimuth real datasets in 3.7 days.
NASA Astrophysics Data System (ADS)
Wilson, G. A.; Cuma, M.; Zhdanov, M. S.; Gribenko, A.; Black, N.
2010-12-01
Three-dimensional (3D) inversion is required for defining 3D geoelectric structures associated with hydrocarbon (HC) deposits from marine controlled-source electromagnetic (CSEM) data. In 3D inversion, regularization is introduced to ensure uniqueness and stability in the inverse model. However, a common misconception is that regularization implies smoothing of the inverse model when in fact regularization and the stabilizing functionals are used to select the class of model from which an inverse solution is sought. Smooth stabilizers represent just one inverse model class from which the minimum norm or first or second derivatives of the 3D resistivity distribution are minimized. Smooth stabilizers have limited physical basis in geological interpretation aimed at exploration for HC reservoirs. Focusing stabilizers on the other hand make it possible to recover subsurface models with sharp resistivity contrasts which are typical for HC reservoirs. Using a synthetic example of the stacked anticlinal structures and reservoir units of the Shtokman gas field in the Barents Sea, we demonstrate that focusing stabilizers not only recover more geologically meaningful models than smooth stabilizers, but they provide better convergence for iterative inversion. This makes it practical to run multiple inversion scenarios based on the suite of a priori models, different data combinations, and various other parameters so as to build confidence in the recovered 3D resistivity model and to discriminate any artifacts that may arise from the interpretation of a single 3D inversion result.
NASA Astrophysics Data System (ADS)
Janssen, G.; Del Val Alonso, L.; Groenendijk, P.; Griffioen, J.
2012-12-01
We developed an on-line coupling between the 1D/quasi-2D nutrient transport model ANIMO and the 3D groundwater transport model code MT3DMS. ANIMO is a detailed, process-oriented model code for the simulation of nitrate leaching to groundwater, N- and P-loads on surface waters and emissions of greenhouse gasses. It is the leading nutrient fate and transport code in the Netherlands where it is used primarily for the evaluation of fertilization related legislation. In addition, the code is applied frequently in international research projects. MT3DMS is probably the most commonly used groundwater solute transport package worldwide. The on-line model coupling ANIMO-MT3DMS combines the state-of-the-art descriptions of the biogeochemical cycles in ANIMO with the advantages of using a 3D approach for the transport through the saturated domain. These advantages include accounting for regional lateral transport, considering groundwater-surface water interactions more explicitly, and the possibility of using MODFLOW to obtain the flow fields. An additional merit of the on-line coupling concept is that it preserves feedbacks between the saturated and unsaturated zone. We tested ANIMO-MT3DMS by simulating nutrient transport for the period 1970-2007 in a Dutch agricultural polder catchment covering an area of 118 km2. The transient groundwater flow field had a temporal resolution of one day and was calculated with MODFLOW-MetaSWAP. The horizontal resolution of the model grid was 100x100m and consisted of 25 layers of varying thickness. To keep computation times manageable, we prepared MT3DMS for parallel computing, which in itself is a relevant development for a large community of groundwater transport modelers. For the parameterization of the soil, we applied a standard classification approach, representing the area by 60 units with unique combinations of soil type, land use and geohydrological setting. For the geochemical parameterization of the deeper subsurface, however, we
Wang, Dafang; Kirby, Robert M; Johnson, Chris R
2011-06-01
We consider the inverse electrocardiographic problem of computing epicardial potentials from a body-surface potential map. We study how to improve numerical approximation of the inverse problem when the finite-element method is used. Being ill-posed, the inverse problem requires different discretization strategies from its corresponding forward problem. We propose refinement guidelines that specifically address the ill-posedness of the problem. The resulting guidelines necessitate the use of hybrid finite elements composed of tetrahedra and prism elements. Also, in order to maintain consistent numerical quality when the inverse problem is discretized into different scales, we propose a new family of regularizers using the variational principle underlying finite-element methods. These variational-formed regularizers serve as an alternative to the traditional Tikhonov regularizers, but preserves the L(2) norm and thereby achieves consistent regularization in multiscale simulations. The variational formulation also enables a simple construction of the discrete gradient operator over irregular meshes, which is difficult to define in traditional discretization schemes. We validated our hybrid element technique and the variational regularizers by simulations on a realistic 3-D torso/heart model with empirical heart data. Results show that discretization based on our proposed strategies mitigates the ill-conditioning and improves the inverse solution, and that the variational formulation may benefit a broader range of potential-based bioelectric problems.
A method to constrain the configuration of the subsurface structure in 3-D gravity inversion
Hu, Y.; Rabinowitz, P.D.
1996-12-31
A three-dimensional inversion technique is developed to investigate the structure of the oceanic crust, using high quality offshore bathymetry, gravity and seismic data. The gravity signatures associated with variations in the thickness of the oceanic crust are isolated from the observed free-air anomaly by subtracting the gravitational effects of seafloor topography and the upper mantle thermal structure, downward continued to the mean depth of the crust/mantle interface and converted onto the relief on that surface. The thickness of the oceanic crust is then calculated by subtracting sea water depth from the depth of the gravity-inferred crust/mantle interface. Seismic refraction data was introduced directly as a constraint in the construction of the initial model for the configuration of the crust/mantle interface and the iterative process of the 3-D joint inversion to reduce the ambiguity in gravity interpretation. This technique can be easily applied to the offshore areas to interpret bathymetry, gravity and seismic data that have been routinely collected for the purpose of geophysical exploration. Compared to the unconstrained gravity inversion, this technique can predict a 3-D crustal model that fits better both gravity and seismic observation data of the study area.
NASA Astrophysics Data System (ADS)
Smirnov, M. Yu.; Korja, T.; Pedersen, L. B.
2009-04-01
Two electromagnetic arrays are used in the EMMA project to study conductivity structure of the Archaean lithosphere in the Fennoscandian Shield. The first array was operated during almost one year, while the second one was running only during the summer time. Twelve 5-components magnetotelluric instruments with fluxgate magnetometers recorded simultaneously time variations of Earth's natural electromagnetic field at the sites separated by c. 30 km. To better control the source field and to obtain galvanic distortion free responses we have applied horizontal spatial gradient (HSG) technique to the data. The study area is highly inhomogeneous, thus classical HSG might give erroneous results. The method was extended to include anomalous field effects by implementing multivariate analysis. The HSG transfer functions were then used to control static shift distortions of apparent resistivities. During the BEAR experiment 1997-2002, the conductance map of entire Fennoscandia was assembled and finally converted into 3D volume resistivity model. We have used the model, refined it to get denser grid around measurement area and calculated MT transfer functions after 3D modeling. We have used trial-and-error method in order to further improve the model. The data set was also inverted using 3D code of Siripunvaraporn (2005). In the first stage we have used homogeneous halfspace as starting model for the inversion. In the next step we have used final 3D forward model as apriori model. The usage of apriori information significantly stabilizes the inverse solution, especially in case of a limited amount of data available. The results show that in the Archaean Domain a conductive layer is found in the upper/middle crust on contrary to previous results from other regions of the Archaean crust in the Fennoscandian Shield. Data also suggest enhanced conductivity at the depth of c. 100 km. Conductivity below the depth of 200-250 km is lower than that of the laboratory based estimates
NASA Astrophysics Data System (ADS)
Corall, Silke; Haraszti, Tamas; Bartoschik, Tanja; Spatz, Joachim Pius; Ludwig, Thomas; Cavalcanti-Adam, Elisabetta Ada
2014-03-01
Cell migration is a crucial event for physiological processes, such as embryonic development and wound healing, as well as for pathological processes, such as cancer dissemination and metastasis formation. Cancer cell migration is a result of the concerted action of matrix metalloproteinases (MMPs), expressed by cancer cells to degrade the surrounding matrix, and integrins, the transmembrane receptors responsible for cell binding to matrix proteins. While it is known that cell-microenvironment interactions are essential for migration, the role of the physical state of such interactions remains still unclear. In this study we investigated human fibrosarcoma cell migration in two-dimensional (2D) and three-dimensional (3D) fibronectin (FN) microenvironments. By using antibody blocking approach and cell-binding site mutation, we determined that -integrin is the main mediator of fibrosarcoma cell migration in 2D FN, whereas in 3D fibrillar FN, the binding of - and -integrins is not necessary for cell movement in the fibrillar network. Furthermore, while the general inhibition of MMPs with GM6001 has no effect on cell migration in both 2D and 3D FN matrices, we observed opposing effect after targeted silencing of a membrane-bound MMP, namely MT1-MMP. In 2D fibronectin, silencing of MT1-MMP results in decreased migration speed and loss of directionality, whereas in 3D FN matrices, cell migration speed is increased and integrin-mediated signaling for actin dynamics is promoted. Our results suggest that the fibrillar nature of the matrix governs the migratory behavior of fibrosarcoma cells. Therefore, to hinder migration and dissemination of diseased cells, matrix molecules should be directly targeted, rather than specific subtypes of receptors at the cell membrane.
3D Effects in the Formation of Zonal Jets Through Inverse Cascade
NASA Astrophysics Data System (ADS)
Sayanagi, Kunio M.; Showman, A. P.
2006-09-01
The atmospheric zonal jets on Jupiter and Saturn are characterized by the broad, prograde, equatorial jet and the narrower, higher-latitude jets that alternate between prograde and retrograde. The question of what controls the widths and directions of those jets remains a major unsolved problem in geophysical fluid dynamics. Past studies have shown that, in shallow flows on a rotating sphere, small random vortices can undergo inverse cascade to form zonal jets with a characteristic width called the Rhines scale. Most of the studies to date use 2D non-divergent or shallow-water models in studying this zonal jet formation mechanism. However, in the parameter ranges representative of the Jovian conditions, the flows produced by 2D non-divergent models are typically dominated by strong circumpolar jets, and the shallow-water models produce a robust retrograde equatorial jet. These models' apparent inabilities in reproducing some key Jovian jet features may suggest the importance of 3D effects in controlling the jets' large-scale horizontal structures. To date, Kitamura and Matsuda (Fluid Dynamics Research, 34, 33-57, 2004) is the only published study that analyzes the 3D effects in the zonalization of fine-scale random turbulence through the inverse cascade. Their two-layer primitive equation simulations of free-evolving flows resulted in circumpolar jet dominated flows, although slower mid-latitude jets are also present. Our study is a significant extension over that by Kitamura and Matsuda and includes substantially more layers to study the zonalization process to more fully resolve relevant 3D effects in the inverse cascade. We test the flow behavior's dependence on the deformation radius and the resulting vertical structures in both spherical and beta-plane geometries. Our study uses the Explicit Planetary Isentropic Coordinate (EPIC) model (Dowling et al, Icarus, 32, 221-238., 1998). The research is supported by a NASA Planetary Atmospheres grant to APS.
3D Effects in the Formation of Zonal Jets Through Inverse Cascade
NASA Astrophysics Data System (ADS)
Sayanagi, K. M.; Showman, A. P.
2006-12-01
The atmospheric zonal jets on Jupiter and Saturn are characterized by the broad, prograde, equatorial jet and the narrower, higher-latitude jets that alternate between prograde and retrograde. The question of what controls the widths and directions of those jets remains a major unsolved problem in geophysical fluid dynamics. Past studies have shown that, in shallow flows on a rotating sphere, small random vortices can undergo inverse cascade to form zonal jets with a characteristic width called the Rhines scale. Most of the studies to date use 2D non-divergent or shallow-water models in studying this zonal jet formation mechanism. However, in the parameter ranges representative of the Jovian conditions, the flows produced by 2D non- divergent models are typically dominated by strong circumpolar jets, and the shallow-water models produce a robust retrograde equatorial jet. These models' apparent inabilities in reproducing some key Jovian jet features may suggest the importance of 3D effects in controlling the jets' large-scale horizontal structures. To date, Kitamura and Matsuda (Fluid Dynamics Research, 34, 33-57, 2004) is the only published study that analyzes the 3D effects in the zonalization of fine-scale random turbulence through the inverse cascade. Their two-layer primitive equation simulations of free-evolving flows resulted in circumpolar jet dominated flows, although slower mid-latitude jets are also present. Our study is a significant extension over that by Kitamura and Matsuda and includes substantially more layers to study the zonalization process to more fully resolve relevant 3D effects in the inverse cascade. We test the flow behavior's dependence on the deformation radius and the resulting vertical structures in both spherical and beta-plane geometries. Our study uses the Explicit Planetary Isentropic Coordinate (EPIC) model (Dowling et al, Icarus, 32, 221-238., 1998). The research is supported by a NASA Planetary Atmospheres grant to APS.
Efficient 2D and 3D multiparameters frequency-domain full waveform inversion (Invited)
NASA Astrophysics Data System (ADS)
Virieux, J.; Operto, S.; Ribodetti, A.; Ben Hadj Ali, H.; Brossier, R.; Etienne, V.; Gholami, Y.; Hu, G.; Jia, Y.; Pageot, D.; Prieux, V.
2010-12-01
With the tremendous increase of the computational power provided by large-scale distributed-memory platforms and the development of dense 3D multi-component wide-aperture/wide-azimuth surveys, full waveform inversion (FWI) introduced in geophysics by Albert Tarantola has become a re-emerging technique to build high-resolution velocity models of the subsurface. Because of the cost of the forward modeling and the high dimensionality of the model space, full waveform inversion is actually a local optimization problem, the aim of which is the minimization of the misfit between the recorded and modeled seismic wavefields. Among all possible minimization criteria, the L1 norm provides the most robust and easy-to-tune criterion. With such criterion, white noise in all seismograms with outliers does not prevent the convergence to the nearly same minimum as for noise-free data. The frequency formulation of the FWI allows coarse sampling of the frequencies data over few frequencies for the reconstruction of the medium when wide-aperture geometries are considered. A preconditioned quasi-Newton L-BFGS modified algorithm provides scaled gradients of the misfit function for each class of parameters. The gradient is computed by the adjoint-state method where the forward field is stored in the core memory of the computer while computing the backpropagation of residuals for cross-correlation at each point of the medium, thanks to the frequency-domain approach. We are using a sequential multiscale hierarchical inversion algorithm with two nested levels of data preconditioning with respect to frequency and first-arrival time. We are able to reconstruct both Vp and Vs velocity structures in various offshore and onshore environments various configurations of crustal investigation where both body waves (and surface) waves are progressively included in the inversion scheme. Solving the forward problem for 2D geometry could be efficiently performed in frequency by using a direct solver
NASA Astrophysics Data System (ADS)
Heincke, B.; Moorkamp, M.; Jegen, M.; Hobbs, R. W.
2012-12-01
Imaging of sub-basalt sediments with reflection seismic techniques is limited due to absorption, scattering and transmission effects and the presence of peg-leg multiples. Although many of the difficulties facing conventional seismic profiles can be overcome by recording long offset data resolution of sub-basalt sediments in seismic sections is typically still largely restricted. Therefore multi-parametric approaches in general and joint inversion strategies in particular (e.g. Colombo et al., 2008, Jordan et al., 2012) are considered as alternative to gain additional information from sub-basalt structures. Here, we combine in a 3-D joint inversion first-arrival time tomography, FTG gravity and MT data to identify the base basalt and resolve potential sediments underneath. For sub-basalt exploration the three methods complement each other such that the null space is reduced and significantly better resolved models can be obtained than would be possible by the individual methods: The seismic data gives a robust model for the supra-basalt sediments whilst the gravity field is dominated by the high density basalt and basement features. The MT on the other hand is sensitive to the conductivity in both the supra- and sub-basalt sediments. We will present preliminary individual and joint inversion result for a FTG, seismic and MT data set located in the Faroe-Shetland basin. Because the investigated area is rather large (~75 x 40 km) and the individual data sets are relatively huge, we use a joint inversion framework (see Moorkamp et al., 2011) which is designed to handle large amount of data/model parameters. This program has moreover the options to link the individual parameter models either petrophysically using fixed parameter relationships or structurally using the cross-gradient approach. The seismic data set consists of a pattern of 8 intersecting wide-angle seismic profiles with maximum offsets of up to ~24 km. The 3-D gravity data set (size :~ 30 x 30 km) is
NASA Astrophysics Data System (ADS)
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%.
NASA Astrophysics Data System (ADS)
Zhdanov, M. S.; Gribenko, A.; Wilson, G. A.
2012-12-01
Geophysical monitoring of reservoir fluids and rock properties is relevant to oil and gas production, carbon sequestration, and enhanced geothermal systems. Different geophysical fields provide information about different physical properties of the earth. Multiple geophysical surveys spanning gravity, magnetic, electromagnetic, seismic, and thermal methods are often interpreted to infer geology from models of different physical properties. In many cases, the various geophysical data are complimentary, making it natural to consider a formal mathematical framework for their joint inversion to a shared earth model. We introduce a new approach to the 3D joint inversion of multiple geophysical datasets using Gramian spaces of model parameters and Gramian constraints, computed as determinants of the corresponding Gram matrices of the multimodal model parameters and/or their attributes. The basic underlying idea of this approach is that the Gramian provides a measure of correlation between the model parameters. By imposing an additional requirement of the minimum of the Gramian, we arrive at the solution of the joint multimodal inverse problem with the enhanced correlation between the different model parameters and/or their attributes. We demonstrate that this new approach is a generalized technique that can be applied to the simultaneous joint inversion of any number and combination of geophysical datasets. Our approach includes as special cases those extant methods based on correlations and/or structural constraints of different physical properties. We illustrate this approach by a model study of reservoir monitoring using different geophysical data.
NASA Astrophysics Data System (ADS)
Kordy, M.; Wannamaker, P.; Maris, V.; Cherkaev, E.; Hill, G.
2016-01-01
We have developed an algorithm, which we call HexMT, for 3-D simulation and inversion of magnetotelluric (MT) responses using deformable hexahedral finite elements that permit incorporation of topography. Direct solvers parallelized on symmetric multiprocessor (SMP), single-chassis workstations with large RAM are used throughout, including the forward solution, parameter Jacobians and model parameter update. In Part I, the forward simulator and Jacobian calculations are presented. We use first-order edge elements to represent the secondary electric field (E), yielding accuracy O(h) for E and its curl (magnetic field). For very low frequencies or small material admittivities, the E-field requires divergence correction. With the help of Hodge decomposition, the correction may be applied in one step after the forward solution is calculated. This allows accurate E-field solutions in dielectric air. The system matrix factorization and source vector solutions are computed using the MKL PARDISO library, which shows good scalability through 24 processor cores. The factorized matrix is used to calculate the forward response as well as the Jacobians of electromagnetic (EM) field and MT responses using the reciprocity theorem. Comparison with other codes demonstrates accuracy of our forward calculations. We consider a popular conductive/resistive double brick structure, several synthetic topographic models and the natural topography of Mount Erebus in Antarctica. In particular, the ability of finite elements to represent smooth topographic slopes permits accurate simulation of refraction of EM waves normal to the slopes at high frequencies. Run-time tests of the parallelized algorithm indicate that for meshes as large as 176 × 176 × 70 elements, MT forward responses and Jacobians can be calculated in ˜1.5 hr per frequency. Together with an efficient inversion parameter step described in Part II, MT inversion problems of 200-300 stations are computable with total run times
New Two-stage Approach For 3d Potential Field Data Inversion
NASA Astrophysics Data System (ADS)
Prutkin, I. L.
From the author's viewpoint the main challenges for a geophysicist dealing with po- tential field data inversion are following: 1) to make really three-dimensional inversion (to avoid the assumption that the object sought is an infinite cylinder); 2) to leave the simplest bodies (prisms, ellipsoids, cylinders of finite length) for the objects of more complex geometry, 3) to take into account the non-uniqueness of the inverse problem. In our investigation we've made an attempt to solve the above-mentioned problems. We take into account the non- uniqueness of the inverse problem in the framework of the equivalence theory developed by A.V. Tsyrulsky. We have reduced 3D grav- ity and magnetic inverse problems to the non-linear integral equations of the 1st kind relative to the function determining geometry of the object sought. They include a physical parameter as a numerical factor. Substituting different values of it, we obtain the opportunity to construct the whole equivalent family of the solutions. New inte- gral equations have been derived, which integrands are algebraic relative the function sought and don't contain its derivatives. The method of local corrections has been suggested, which makes it possible to curtail the time required to solve an inverse problem approximately by an order of magnitude. The parameterization of the solu- tion sought and regularization of an inverse problem were studied. On the base of his equivalence theory A.V. Tsyrulsky had suggested two-stage approach for 2D gravity and magnetic anomalies interpretation. The aim of the first stage is to approximate the observed field by the field of a sum of the simplest sources (point sources, thin layers, etc.) of no geological sense. On the second stage the field of a sum of some sources is regarded as a field of the object sought, we are able to try different variants to unite sources and to construct the equivalent family of solutions. Sole member of the family should be chosen with taking
NASA Astrophysics Data System (ADS)
Yang, Pengliang; Brossier, Romain; Métivier, Ludovic; Virieux, Jean
2016-07-01
In this paper we study 3D multiparameter full waveform inversion (FWI) in viscoelastic media based on the generalized Maxwell/Zener body (GMB/GZB) including arbitrary number of attenuation mechanisms. We present a frequency-domain energy analysis to establish the stability condition of a full anisotropic viscoelastic system, according to zero-valued boundary condition and the elastic-viscoelastic correspondence principle: the real-valued stiffness matrix becomes a complex-valued one in Fourier domain when seismic attenuation is taken into account. We develop a least-squares optimization approach to linearly relate the quality factor with the anelastic coefficients by estimating a set of constants which are independent of the spatial coordinates, which supplies an explicit incorporation of the parameter Q in the general viscoelastic wave equation. By introducing the Lagrangian multipliers into the matrix expression of the wave equation with implicit time integration, we build a systematic formulation of multiparameter full waveform inversion for full anisotropic viscoelastic wave equation, while the equivalent form of the state and adjoint equation with explicit time integration is available to be resolved efficiently. In particular, this formulation lays the foundation for the inversion of the parameter Q in the time domain with full anisotropic viscoelastic properties. In the 3D isotropic viscoelastic settings, the anelastic coefficients and the quality factors using bulk and shear moduli parameterization can be related to the counterparts using P- and S- velocity. Gradients with respect to any other parameter of interest can be found by chain rule. Pioneering numerical validations as well as the real applications of this most generic framework will be carried out to disclose the potential of viscoelastic FWI when adequate high performance computing resources and the field data are available.
NASA Astrophysics Data System (ADS)
Campanyà, Joan; Ogaya, Xènia; Jones, Alan G.; Rath, Volker; Vozar, Jan; Meqbel, Naser
2016-09-01
As a consequence of measuring time variations of the electric and the magnetic field, which are related to current flow and charge distribution, magnetotelluric (MT) data in two dimensional (2-D) and three dimensional (3-D) environments are not only sensitive to the geoelectrical structures below the measuring points but also to any lateral anomalies surrounding the acquisition site. This behaviour complicates the characterisation of the electrical resistivity distribution of the subsurface, particularly in complex areas. In this manuscript we assess the main advantages of complementing the standard MT impedance tensor (Z) data with inter-station horizontal magnetic tensor (H) and geomagnetic transfer function (T) data in constraining the subsurface in a 3-D environment beneath a MT profile. Our analysis was performed using synthetic responses with added normally distributed and scattered random noise. The sensitivity of each type of data to different resistivity anomalies is evaluated, showing that the degree to which each site and each period is affected by the same anomaly depends on the type of data. A dimensionality analysis, using Z, H and T data, identifies the presence of the 3-D anomalies close to the profile, suggesting a 3-D approach for recovering the electrical resistivity values of the subsurface. Finally, the capacity for recovering the geoelectrical structures of the subsurface is evaluated by performing joint inversion using different data combinations, quantifying the differences between the true synthetic model and the models from inversion process. Four main improvements are observed when performing joint inversion of Z, H and T data: (1) superior precision and accuracy at characterising the electrical resistivity values of the anomalies below and outside the profile; (2) the potential to recover high electrical resistivity anomalies that are poorly recovered using Z data alone; (3) improvement in the characterization of the bottom and lateral
Data-driven inversion of 3D GPR data for layered media
NASA Astrophysics Data System (ADS)
Slob, E. C.
2013-12-01
The number of GPR applications is large and still increasing. In several applications fixed-offset measurements can be sufficient and many dedicated imaging and inversion methods have been developed. Because there is insufficient amounts of data, these are necessarily model-driven schemes. For problems where quantitative information is needed, usually it is better to record multi-offset and possibly multicomponent data. Even for this data inversion is usually model-driven. This means the inverse problem is formulated as an iterative forward modeling problem and is solved by minimizing the amplitude difference between modeled and measured data. The model is modified such that data computed from the model fits the measured data. The information in the measured data itself is not used, except as a measure of the model data fit. For multi-offset multicomponent data a data-driven scheme is here developed to perform full waveform inversion of 3D ground-penetrating radar reflection data acquired on the surface of a layered medium. For data-driven models to work well, the data has to be properly sampled. The advantage is that no model information is necessary to carry out the inversion. The inversion is carried out in three steps. First the data is decomposed into up- and downgoing wave modes. In a layered earth the two modes are separable and are treated separately. This step provides the reflection response of the layered medium. For 3D waves in a layered medium this requires knowledge of the horizontal electric and magnetic field components. If the data is properly sampled the solution is unique. The second step consists of wave field synthesis, where the reflection response is used to construct a focusing wave field that can focus in a virtual receiver position at any depth level. At this stage of the process the depth level is only known in terms of one-way travel time. This is the intercept time in the slowness domain obtained directly from the data. A virtual
3D CSEM data inversion using Newton and Halley class methods
NASA Astrophysics Data System (ADS)
Amaya, M.; Hansen, K. R.; Morten, J. P.
2016-05-01
For the first time in 3D controlled source electromagnetic data inversion, we explore the use of the Newton and the Halley optimization methods, which may show their potential when the cost function has a complex topology. The inversion is formulated as a constrained nonlinear least-squares problem which is solved by iterative optimization. These methods require the derivatives up to second order of the residuals with respect to model parameters. We show how Green's functions determine the high-order derivatives, and develop a diagrammatical representation of the residual derivatives. The Green's functions are efficiently calculated on-the-fly, making use of a finite-difference frequency-domain forward modelling code based on a multi-frontal sparse direct solver. This allow us to build the second-order derivatives of the residuals keeping the memory cost in the same order as in a Gauss-Newton (GN) scheme. Model updates are computed with a trust-region based conjugate-gradient solver which does not require the computation of a stabilizer. We present inversion results for a synthetic survey and compare the GN, Newton, and super-Halley optimization schemes, and consider two different approaches to set the initial trust-region radius. Our analysis shows that the Newton and super-Halley schemes, using the same regularization configuration, add significant information to the inversion so that the convergence is reached by different paths. In our simple resistivity model examples, the convergence speed of the Newton and the super-Halley schemes are either similar or slightly superior with respect to the convergence speed of the GN scheme, close to the minimum of the cost function. Due to the current noise levels and other measurement inaccuracies in geophysical investigations, this advantageous behaviour is at present of low consequence, but may, with the further improvement of geophysical data acquisition, be an argument for more accurate higher-order methods like those
Levander, Alan Richard; Zelt, Colin A.
2015-03-17
The work plan for this project was to develop and apply advanced seismic reflection and wide-angle processing and inversion techniques to high resolution seismic data for the shallow subsurface to seismically characterize the shallow subsurface at hazardous waste sites as an aid to containment and cleanup activities. We proposed to continue work on seismic data that we had already acquired under a previous DoE grant, as well as to acquire additional new datasets for analysis. The project successfully developed and/or implemented the use of 3D reflection seismology algorithms, waveform tomography and finite-frequency tomography using compressional and shear waves for high resolution characterization of the shallow subsurface at two waste sites. These two sites have markedly different near-surface structures, groundwater flow patterns, and hazardous waste problems. This is documented in the list of refereed documents, conference proceedings, and Rice graduate theses, listed below.
The 3D inversion of airborne gamma-ray spectrometric data
NASA Astrophysics Data System (ADS)
Minty, Brian; Brodie, Ross
2016-07-01
We present a new method for the inversion of airborne gamma-ray spectrometric line data to a regular grid of radioelement concentration estimates on the ground. The method incorporates the height of the aircraft, the 3D terrain within the field of view of the spectrometer, the directional sensitivity of rectangular detectors, and a source model comprising vertical rectangular prisms with the same horizontal dimensions as the required grid cell size. The top of each prism is a plane surface derived from a best-fit plane to the digital elevation model of the earth's surface within each grid cell area. The method is a significant improvement on current methods, and gives superior interpolation between flight lines. It also eliminates terrain effects that would normally remain in the data after the conventional processing of these data assuming a flat-earth model.
Inverse modeling of InSAR and ground leveling data for 3D volumetric strain distribution
NASA Astrophysics Data System (ADS)
Gallardo, L. A.; Glowacka, E.; Sarychikhina, O.
2015-12-01
Wide availability of modern Interferometric Synthetic aperture Radar (InSAR) data have made possible the extensive observation of differential surface displacements and are becoming an efficient tool for the detailed monitoring of terrain subsidence associated to reservoir dynamics, volcanic deformation and active tectonism. Unfortunately, this increasing popularity has not been matched by the availability of automated codes to estimate underground deformation, since many of them still rely on trial-error subsurface model building strategies. We posit that an efficient algorithm for the volumetric modeling of differential surface displacements should match the availability of current leveling and InSAR data and have developed an algorithm for the joint inversion of ground leveling and dInSAR data in 3D. We assume the ground displacements are originated by a stress free-volume strain distribution in a homogeneous elastic media and determined the displacement field associated to an ensemble of rectangular prisms. This formulation is then used to develop a 3D conjugate gradient inversion code that searches for the three-dimensional distribution of the volumetric strains that predict InSAR and leveling surface displacements simultaneously. The algorithm is regularized applying discontinuos first and zero order Thikonov constraints. For efficiency, the resulting computational code takes advantage of the resulting convolution integral associated to the deformation field and some basic tools for multithreading parallelization. We extensively test our algorithm on leveling and InSAR test and field data of the Northwest of Mexico and compare to some feasible geological scenarios of underground deformation.
NASA Astrophysics Data System (ADS)
Yang, Pengliang; Brossier, Romain; Métivier, Ludovic; Virieux, Jean
2016-10-01
In this paper, we study 3-D multiparameter full waveform inversion (FWI) in viscoelastic media based on the generalized Maxwell/Zener body including arbitrary number of attenuation mechanisms. We present a frequency-domain energy analysis to establish the stability condition of a full anisotropic viscoelastic system, according to zero-valued boundary condition and the elastic-viscoelastic correspondence principle: the real-valued stiffness matrix becomes a complex-valued one in Fourier domain when seismic attenuation is taken into account. We develop a least-squares optimization approach to linearly relate the quality factor with the anelastic coefficients by estimating a set of constants which are independent of the spatial coordinates, which supplies an explicit incorporation of the parameter Q in the general viscoelastic wave equation. By introducing the Lagrangian multipliers into the matrix expression of the wave equation with implicit time integration, we build a systematic formulation of multiparameter FWI for full anisotropic viscoelastic wave equation, while the equivalent form of the state and adjoint equation with explicit time integration is available to be resolved efficiently. In particular, this formulation lays the foundation for the inversion of the parameter Q in the time domain with full anisotropic viscoelastic properties. In the 3-D isotropic viscoelastic settings, the anelastic coefficients and the quality factors using bulk and shear moduli parametrization can be related to the counterparts using P and S velocity. Gradients with respect to any other parameter of interest can be found by chain rule. Pioneering numerical validations as well as the real applications of this most generic framework will be carried out to disclose the potential of viscoelastic FWI when adequate high-performance computing resources and the field data are available.
3D elastic full waveform inversion: case study from a land seismic survey
NASA Astrophysics Data System (ADS)
Kormann, Jean; Marti, David; Rodriguez, Juan-Esteban; Marzan, Ignacio; Ferrer, Miguel; Gutierrez, Natalia; Farres, Albert; Hanzich, Mauricio; de la Puente, Josep; Carbonell, Ramon
2016-04-01
Full Waveform Inversion (FWI) is one of the most advanced processing methods that is recently reaching a mature state after years of solving theoretical and technical issues such as the non-uniqueness of the solution and harnessing the huge computational power required by realistic scenarios. BSIT (Barcelona Subsurface Imaging Tools, www.bsc.es/bsit) includes a FWI algorithm that can tackle with very complex problems involving large datasets. We present here the application of this system to a 3D dataset acquired to constrain the shallow subsurface. This is where the wavefield is the most complicated, because most of the wavefield conversions takes place in the shallow region and also because the media is much more laterally heterogeneous. With this in mind, at least isotropic elastic approximation would be suitable as kernel engine for FWI. The current study explores the possibilities to apply elastic isotropic FWI using only the vertical component of the recorded seismograms. The survey covers an area of 500×500 m2, and consists in a receivers grid of 10 m×20 m combined with a 250 kg accelerated weight-drop as source on a displaced grid of 20 m×20 m. One of the main challenges in this case study is the costly 3D modeling that includes topography and substantial free surface effects. FWI is applied to a data subset (shooting lines 4 to 12), and is performed for 3 frequencies ranging from 15 to 25 Hz. The starting models are obtained from travel-time tomography and the all computation is run on 75 nodes of Mare Nostrum supercomputer during 3 days. The resulting models provide a higher resolution of the subsurface structures, and show a good correlation with the available borehole measurements. FWI allows to extend in a reliable way this 1D knowledge (borehole) to 3D.
3D maps of the local ISM from inversion of individual color excess measurements
NASA Astrophysics Data System (ADS)
Lallement, R.; Vergely, J.-L.; Valette, B.; Puspitarini, L.; Eyer, L.; Casagrande, L.
2014-01-01
Aims: Three-dimensional (3D) maps of the Galactic interstellar matter (ISM) are a potential tool of wide use, but accurate and detailed maps are still lacking. One of the ways to construct the maps is to invert individual distance-limited ISM measurements, a method we have applied here to measurements of stellar color excess in the optical. Methods: We assembled color excess data together with the associated parallax or photometric distances to constitute a catalog of ≃23 000 sightlines for stars within 2.5 kpc. The photometric data are taken from Strömgren catalogs, the Geneva photometric database, and the Geneva-Copenhagen survey. We also included extinctions derived towards open clusters. We applied an inversion method based on a regularized Bayesian approach to this color excess dataset, a method previously used for mapping at closer distances. Results: We show the dust spatial distribution resulting from the inversion by means of planar cuts through the differential opacity 3D distribution, and by means of 2D maps of the integrated opacity from the Sun up to various distances. The mapping assigns locations to the nearby dense clouds and represents their distribution at the spatial resolution that is allowed by the dataset properties, i.e. ≃10 pc close to the Sun and increasing to ≃100 pc beyond 1 kpc. Biases toward nearby and/or weakly extincted stars make this dataset particularly appropriate to mapping the local and neighboring cavities and to locating faint, extended nearby clouds, which are both goals that are difficult or impossible with other mapping methods. The new maps reveal a ≃1 kpc wide empty region in the third quadrant in the continuation of the so-called CMa tunnel of the Local Cavity, a cavity that we identify as the Superbubble GSH238+00+09 detected in radio emission maps and that is found to be bounded by the Orion and Vela clouds. The maps also show an extended narrower tunnel in the opposite direction (l ≃ 70°) that also extends
3D-marine tCSEM inversion using model reduction in the Rational Krylov subspace
NASA Astrophysics Data System (ADS)
Sommer, M.; Jegen, M. D.
2014-12-01
Computationally, the most expensive part of a 3D time domain CSEM inversion is the computation of the Jacobian matrix in every Gauss-Newton step. An other problem is its size for large data sets. We use a model reduction method (Zaslavsky et al, 2013), that compresses the Jacobian by projecting it with a Rational Krylov Subspace (RKS). It also reduces the runtime drastically, compared to the most common adjoint approach and was implemented on GPU.It depends on an analytic derivation of the implicit Anzatz function, which solves Maxwell's diffusion equation in the Eigenspace giving a Jacobian dependent on the Eigenpairs and its derivatives of the forward problem. The Eigenpairs are approximated by Ritz-pairs in the Rational Krylov subspace. Determination of the derivived Ritz-pairs is the most time consuming and was fully GPU-optimized. Furthermore, the amount of inversion cells is reduced by using Octree meshes. The gridding allows for the incorporation of complicated survey geometries, as they are encountered in marine CSEM datasets.As a first result, the Jacobian computation is, even on a Desktop, faster than the most common adjoint approach on a super computer for realistic data sets. We will present careful benchmarking and accuracy tests of the new method and show how it can be applied to a real marine scenario.
KOALA: 3-D shape of asteroids from multi-data inversion
NASA Astrophysics Data System (ADS)
Carry, B.; Kaasalainen, M.; Merline, W. J.; Drummond, J. D.; Durech, J.; Berthier, J.; Conrad, A.
2011-10-01
We describe our on-going observing program to determine the physical properties of asteroids from groundbased facilities. We combine disk-resolved images from adaptive optics, optical lightcurves, and stellar occultations to put tighter constraints on the spin, 3-D shape, and size of asteroids. We will discuss the relevance of the determination of physical properties to help understand the asteroid population (e.g., density, composition, and non-gravitational forces). We will then briefly describe our multi-data inversion algorithm KOALA (Carry et al. 2010a, Kaasalainen 2011, see also Kaasalainen et al., same meeting), which allows the determination of certain physical properties of an asteroid from the combination of different techniques of observation. A comparison of results obtained with KOALA on asteroid (21) Lutetia, prior to the ESA Rosetta flyby, with the high spatial resolution images returned from that flyby, will then be presented, showing the high accuracy of KOALA inversion. Finally, we will describe our current development of the algorithm, and focus on examples of other asteroids currently being studied with KOALA.
Inverse cascades sustained by the transfer rate of angular momentum in a 3D turbulent flow
NASA Astrophysics Data System (ADS)
Burguete, Javier; Lopez-Caballero, Miguel
2013-11-01
The existence of energy cascades as signatures of conserved magnitudes is one of the universal characteristics of turbulent flows. In this work we present the evidence of an inverse cascade in a fully developed 3D experimental turbulent flow where the conserved magnitude is the angular momentum. We analyze the behavior of a fluid in a closed cavity where two inhomogeneous and strongly turbulent flows collide in a thin region. The experimental volume is a closed cylinder (diameter of 20 cm) where two impellers rotate in opposite directions. A key characteristic of this setup the high stability of the propellers (the instantaneous fluctuations are below 0 . 1 %). We have performed PIV and LDA measurements of the velocity fields. Typical characteristics of the turbulent flow in this setup are: turbulence intensity 50 % , the Reλ = 900 , the Taylor microscale λT = 1 . 8 mm and the integral scale LI = 15 mm. The analysis of the data series reveal that below the injection scales an inverse cascade can be identified (-1/3 in time, -7/3 in space) that can be explained as the transfer of angular momentum between the diferent fluid layers. A. de la Torre, J. Burguete, Phys Rev Lett 99 (2007) 054101. M. Lopez-Caballero, J. Burguete, Phys Rev Lett 110 (2013) 124501.
An optimal transport approach for seismic tomography: application to 3D full waveform inversion
NASA Astrophysics Data System (ADS)
Métivier, L.; Brossier, R.; Mérigot, Q.; Oudet, E.; Virieux, J.
2016-11-01
the L 2 distance, in 2D and 3D contexts.
Centroid Moment Tensor Inversion in a 3D heterogeneous Earth: Application to the Australasian region
NASA Astrophysics Data System (ADS)
Hejrani, B.; Tkalcic, H.; Fichtner, A.
2015-12-01
radially anisotropic structure: new insights into present and past states of the Australasian upper mantle. Earth Planet. Sci. Lett. 290, 270-280. Hingee, M., Tkalčić, H., Fichtner A., Sambridge, M., 2011. Moment tensor inversion using a 3-D structural model: Applications for the Australian region, Geophys. J. Int., 184(2), 949-964.
NASA Astrophysics Data System (ADS)
Kunyansky, Leonid A.
2004-10-01
The inversion problem for the 3D parallel-beam exponential ray transform is solved through inversion of a set of the 2D exponential Radon transforms with complex-valued angle-dependent attenuation. An inversion formula for the latter 2D transform is derived; it generalizes the known Kuchment-Shneiberg formula valid for real angle-dependent attenuation. We derive an explicit theoretically exact solution of the 3D problem which is valid for arbitrary closed trajectory that does not intersect itself. A simple reconstruction algorithm is described, applicable for certain sets of trajectories satisfying Orlov's condition. In the latter case, our inversion technique is as stable as the Tretiak-Metz inversion formula. Possibilities of further reduction of noise sensitivity are briefly discussed in the paper. The work of our algorithm is illustrated by an example of image reconstruction from two circular orbits.
NASA Astrophysics Data System (ADS)
Kim, B.; Byun, J.; Seol, S. J.; Jeong, S.; Chung, Y.; Kwon, T.
2015-12-01
For many decades, gas hydrates have been received great attention as a potential source of natural gas. Therefore, the detailed information of structures of buried gas hydrates and their concentrations are prerequisite for the production for the gas hydrate as a reliable source of alternate energy. Recently, for this reason, a lot of gas hydrate assessment methods have been proposed by many researchers. However, it is still necessary to establish as new method for the further improvement of the accuracy of the 3D gas hydrate distribution. In this study, we present a 3D joint inversion method that provides superior quantitative information of gas hydrate distributions using 3D seismic data obtained by ocean-bottom cable (OBC) and marine controlled-source electromagnetic (CSEM) data. To verify our inversion method, we first built the general 3D gas hydrate model containing vertical methane-flow pathways. With the described model, we generated synthetic 3D OBC data and marine CSEM data using finite element modeling algorithms, respectively. In the joint inversion process, to obtain the high-resolution volumetric P-wave velocity structure, we applied the 3D full waveform inversion algorithm to the acquired OBC data. After that, the obtained P-wave velocity model is used as the structure constraint to compute cross-gradients with the updated resistivity model in the EM inversion process. Finally, petrophysical relations were applied to estimate volumetric gas hydrate concentrations. The proposed joint inversion process makes possible to obtain more precise quantitative gas hydrate assessment than inversion processes using only seismic or EM data. This technique can be helpful for accurate decision-making in gas hydrate development as well as in their production monitoring.
Understanding how Fault-bounded Blocks Deform in 3D by Inverse Modelling
NASA Astrophysics Data System (ADS)
Jouen, G.; White, N.
2004-05-01
Normal faults play a crucial role in modifying basin stratigraphy. At the exploration scale, the internal deformation of tilted blocks is governed by the three-dimensional geometry of large-scale faults which bound these blocks. At the reservoir scale, the geometry and growth of normal faulting control the deformation of strata and the compartmentalisation of reservoir intervals. Despite their importance, large-scale normal faults are often difficult to image. The purpose of structural validation is two-fold: to determine the 3D shape of normal faults and to investigate the relationship between fault geometry and deformed stratigraphy including the intra-block faults. We have developed methods for tackling structural validation at a variety of scales in two and three dimensions. The cornerstone of our approach is the use of geophysical inverse theory to calculate optimal fault geometries from deformed strata. This approach allows us to focus on key questions: does a solution exist? Are there several possible solutions or just one unique one? In a complex normal fault system, which part of the fault controls the motion responsible for the deformation in the hanging-wall? Traditional forward modelling cannot answer these fundamental issues. We have applied the inversion on seismic data in particularly complex areas in the northern North Sea. The aims of this project are to determine the geometry of the basin-bounding fault, to assess the likelihood of out-of-plane motion as well as understanding the mode of deformation leading to the complexity of the present structure. Closely spaced inverse models show that the basin-bounding fault on the UK side is steeper and more planar than previously thought. This method also helped us to have a better view of what could have been the cause of the organisation and density of the intra-block faulting where it occurs. The North Cormorant study has shown how inverse modelling can yield important, quantitative, insights. Our
NASA Astrophysics Data System (ADS)
Rosenkjaer, G. K.; Heagy, L. J.; Cockett, R.; Kang, S.
2015-12-01
The MagnetoTelluric (MT) method is widely used in geophysical exploration, especially in geothermal exploration. The extensive frequency range allows mapping the resistivity structure to greater depths than typically achieved using controlled sources (on the order of 10 km's). This is advantageous in identifying structures of interest, such as those related to hydrothermal alterations in a geothermal system and the heat source of the system. To obtain information about subsurface resistivity structures from MT data, an inversion modelling is commonly performed. The goal of an inversion is to recover a resistivity model that explains the data (within a degree of accuracy), given sets of constraints on the model. An attention to detail, often through an iterative process, is required during the inversion. A workflow that is transparent and repeatable is important for addressing the complexities encountered in an inversion and make the iterative process more effective. In this presentation, we will show examples of a workflow for an inversion of MT data from the Krysuvik geothermal area in Iceland. The workflow is implemented as a Python script, where the SimPEG framework (http://simpeg.xyz) is used to implement an open-source code base to work with MT data . The SimPEG framework uses finite-volume discretizations for structured and semi-structured meshes and has built-in routines for optimization and regularization. By structuring and writing the simpegMT code in compliance with the modular, object-oriented framework of SimPEG, full compatibility is achieved and its functions can be leveraged directly. Further, the structure facilitates interoperability with other problem-types, streamlines testing and fosters cooperations between developers and users of the code. We will step through the workflow, where varying complexity leads to a recovery of 3D models of different detail. We show how we guide steps in the workflow based on the preceding results, iteratively
NASA Astrophysics Data System (ADS)
Meqbel, Naser M.; Egbert, Gary D.; Wannamaker, Philip E.; Kelbert, Anna; Schultz, Adam
2014-09-01
Long period (10-20,000 s) magnetotelluric (MT) data are being acquired across the continental USA on a quasi-regular grid of ˜70 km spacing as an electromagnetic component of the National Science Foundation EarthScope/USArray Program. These data are sensitive to fluids, melts, and other orogenic indicators, and thus provide a valuable complement to other components of EarthScope. We present and interpret results of 3-D MT data inversion from 325 sites acquired from 2006-2011 to provide a regional scale view of electrical resistivity from the middle crust to nearly the mantle transition zone, covering an area from NW Washington to NW Colorado. Beneath the active extensional subprovinces in the south-central region, on average we see a resistive upper crust, and then extensive areas of low resistivity in the lower crust and uppermost mantle. Further below, much of the upper half of the upper mantle appears moderately resistive, then subsequently the lower upper mantle becomes moderately conductive. This column suggests a dynamic process of moderately hydrated and fertile deeper upper mantle upwelling during extension, intersection of that material with the damp solidus causing dehydration and melting, and upward exodus of generated mafic melts to pond and exsolve saline fluids near Moho levels. Lithosphere here is very thin. To the east and northeast, thick sections of resistive lithosphere are imaged under the Wyoming and Medicine Hat Cratons. These are punctuated with numerous electrically conductive sutures presumably containing graphitic or sulfide-bearing meta-sediments deeply underthrust and emplaced during ancient collisions. Below Cascadia, the subducting Juan de Fuca and Gorda lithosphere appears highly resistive. Suspected oceanic lithosphere relicts in the central NW part of the model domain also are resistive, including the accreted “Siletzia” terrane beneath the Coast Ranges and Columbia Embayment, and the seismically fast “slab curtain” beneath
Xie, G.; Li, J.; Majer, E.; Zuo, D.
1998-07-01
This paper describes a new 3D parallel GILD electromagnetic (EM) modeling and nonlinear inversion algorithm. The algorithm consists of: (a) a new magnetic integral equation instead of the electric integral equation to solve the electromagnetic forward modeling and inverse problem; (b) a collocation finite element method for solving the magnetic integral and a Galerkin finite element method for the magnetic differential equations; (c) a nonlinear regularizing optimization method to make the inversion stable and of high resolution; and (d) a new parallel 3D modeling and inversion using a global integral and local differential domain decomposition technique (GILD). The new 3D nonlinear electromagnetic inversion has been tested with synthetic data and field data. The authors obtained very good imaging for the synthetic data and reasonable subsurface EM imaging for the field data. The parallel algorithm has high parallel efficiency over 90% and can be a parallel solver for elliptic, parabolic, and hyperbolic modeling and inversion. The parallel GILD algorithm can be extended to develop a high resolution and large scale seismic and hydrology modeling and inversion in the massively parallel computer.
Statistical Inverse Ray Tracing for Image-Based 3D Modeling.
Liu, Shubao; Cooper, David B
2014-10-01
This paper proposes a new formulation and solution to image-based 3D modeling (aka "multi-view stereo") based on generative statistical modeling and inference. The proposed new approach, named statistical inverse ray tracing, models and estimates the occlusion relationship accurately through optimizing a physically sound image generation model based on volumetric ray tracing. Together with geometric priors, they are put together into a Bayesian formulation known as Markov random field (MRF) model. This MRF model is different from typical MRFs used in image analysis in the sense that the ray clique, which models the ray-tracing process, consists of thousands of random variables instead of two to dozens. To handle the computational challenges associated with large clique size, an algorithm with linear computational complexity is developed by exploiting, using dynamic programming, the recursive chain structure of the ray clique. We further demonstrate the benefit of exact modeling and accurate estimation of the occlusion relationship by evaluating the proposed algorithm on several challenging data sets.
Wang, G.L.; Chew, W.C.; Cui, T.J.; Aydiner, A.A.; Wright, D.L.; Smith, D.V.
2004-01-01
Three-dimensional (3D) subsurface imaging by using inversion of data obtained from the very early time electromagnetic system (VETEM) was discussed. The study was carried out by using the distorted Born iterative method to match the internal nonlinear property of the 3D inversion problem. The forward solver was based on the total-current formulation bi-conjugate gradient-fast Fourier transform (BCCG-FFT). It was found that the selection of regularization parameter follow a heuristic rule as used in the Levenberg-Marquardt algorithm so that the iteration is stable.
Inks, T.L.; Agena, W.F.
2008-01-01
In February 2007, the Mt. Elbert Prospect stratigraphic test well, Milne Point, North Slope Alaska encountered thick methane gas hydrate intervals, as predicted by 3D seismic interpretation and modeling. Methane gas hydrate-saturated sediment was found in two intervals, totaling more than 100 ft., identified and mapped based on seismic character and wavelet modeling.
NASA Astrophysics Data System (ADS)
Meqbel, N. M.; Egbert, G. D.; Kelbert, A.
2010-12-01
Long period (10-20,000 s) magnetotelluric (MT) data are being acquired in a series of temporary arrays deployed across the continental United States through EMScope, a component of EarthScope, a multidisciplinary decade-long project to study the structure and evolution of the North American Continent. MT deployments in 2006-2010 have so far acquired data at 237 sites on an approximately regular grid, with the same nominal spacing as the USArray broadband seismic transportable array (~70 km), covering the Northwestern US, from the Oregon-Washington coast across the Rocky Mountains, into Montana and Wyoming. Preliminary 3-D inversion results (Patro and Egbert; 2008), based on data from the 110 westernmost “Cascadia” sites collected in the first two years, revealed extensive areas of high conductivity in the lower crust beneath the Northwest Basin and Range (NBR), inferred to result from fluids (including possibly partial melt at depth) associated with magmatic underplating, and beneath the Cascade Mountains, probably due to fluids released by the subducting Juan de Fuca slab. Here we extend this study, refining and further testing the preliminary results from Cascadia, and extending the inversion domain to the East, to include all of the EarthScope data. Although site spacing is very broad, distinct regional structures are clearly evident even in simple maps of apparent resistivity, phase and induction vectors. For the 3-D inversion we are using the parallelized version of our recently developed Modular Code (ModEM), which supports Non-Linear Conjugate Gradient and several Gauss-Newton type schemes. Our initial 3-D inversion results using 212 MT sites, fitting impedances and vertical field transfer functions (together and separately) suggest several conductive and resistive structures which appear to be stable and required by the measured data. These include: - A conductive structure elongated in the N-S direction underneath the volcanic arc of the Cascadia
Lithospheric structure of the Labrador Sea from constrained 3-D gravity inversion
NASA Astrophysics Data System (ADS)
Welford, J. Kim; Hall, Jeremy
2013-11-01
Regional inversions of free air gravity data constrained by bathymetric and sediment thickness information were undertaken over the Labrador Sea and its margins to generate 3-D density anomaly models to investigate broad-scale crustal structural variations across the extinct spreading centre. Benchmarked against independent seismic Moho depth constraints, a density anomaly isosurface within the inverted volumes was selected as a Moho-proxy and regional maps of Moho structure were developed. Inversions using two different sources for depth to basement constraints revealed similar Moho structures with a depth to Moho of 12 km beneath the Labrador Sea which deepens to 20 km and greater towards Davis Strait and beneath the offshore extension of the Grenville Province. Density anomaly slices through the models corresponding to seismic lines show good agreement between the inverted Moho-proxy and the seismic Moho, with the only exceptions occurring where a high velocity lower crustal zone or underplate has been modelled from wide-angle reflection/refraction profiling studies. The inverted depth to Moho estimates were combined with depth to basement constraints to investigate crustal thickness, both for the full crust and for individual crustal layers, revealing that the crust of the Labrador Sea is generally 5-10 km thick but thickens to 20-25 km towards Davis Strait and beneath the offshore extension of the Grenville Province, not taking into account high density underplates or anomalously high density lower crust. Sediment and crustal thickness variations were investigated to compute stretching factors, β, across the Labrador Sea and to identify zones which deviate from local isostatic compensation. Assuming both an initial unstretched crustal thickness of 35 km and using a variable unstretched crustal thickness model, much of the Labrador Sea has experienced 70-90 per cent thinning. The derived β values suggest that embrittlement of the entire crust and
NASA Astrophysics Data System (ADS)
Kelbert, A.; Schultz, A.
2004-12-01
The case for substantial heterogeneity in mantle conductivity has stimulated the development of methods for solving Maxwell's equations in a heterogeneous conducting sphere. A global 3-D frequency domain forward solver has been devised (Uyeshima & Schultz, 2000), accurate and efficient enough to be an attractive kernel of a practical inverse method. The solver employs a staggered-grid finite difference formulation in spherical coordinates. The induced fields are found as a solution to the integral form of Maxwell's equations, while the system is solved using stabilised biconjugate gradient methods. A single, accurate forward solution takes approx. 4 minutes on 5 GFLOP (peak) processor. The aim of our present research is to produce an inverse solver, to be applied to the Fujii & Schultz (2002) data set of globally-distributed EM response functions, which would reconstruct the 3-D electrical conductivity distribution in the upper to mid-mantle. Geophysical inversion is an ill-posed problem, therefore the aim is to apply suitable parameter constraints and a nonlinear search algorithm to identify candidate minima, then to apply local gradient methods around those minima. Our specific target involves designing a fast enough global optimisation routine that would allow us to produce at least one fully 3-D starting model, optimal with respect to the RMS misfit between the data and the forward solutions. A new and very flexible inverse solver has been developed utilizing parallel optimisation routines to obtain a starting model that satisfies the data. 3-D simulations have been run, the parametrization based on a spherical harmonic representation of a chess board model of varying degree and order. The inversion has demonstrated accurate fidelity in reproducing resolvable features of the test model. A study has been made of the reduction in fidelity as the number and distribution of observatory sites on the Earth's surface is degraded. An inversion of the Fujii & Schultz
NASA Astrophysics Data System (ADS)
Prutkin, Ilya; Vajda, Peter; Jentzsch, Gerhard
2016-04-01
wavelengths for the Thuringian Basin have shown, that if we explain negative anomalies with topography of near-surface layers, the obtained solution is not supported by boreholes data. Upper part of a geological section is usually well studied, therefore, it is not always possible, to shift sources upward, because it can contradict to available geological information. For each local anomaly, its interpretation includes several steps. We subtract the model of the regional field (2D harmonic function). Then, we approximate the residuals with 3D line segments, it provides reliable estimates for mass and center of mass coordinates. For the Kolarovo anomaly of 25 mGal, residuals by approximation have RMS = 0.57 mGal. Here we find very few parameters (14 for two segments) according to several thousand observations, which is quite stable. Finally, we transform a chosen set of line segments into a restricted object or a contact surface with the same field (in the situation where a solution of the inverse problem is unique). We have obtained a model for intermediate wavelengths in the Thuringian Basin, which includes three restricted bodies (granitic intrusions) and a density interface with topography below them.
Bedekar, Vivek; Morway, Eric D.; Langevin, Christian D.; Tonkin, Matthew J.
2016-09-30
MT3D-USGS, a U.S. Geological Survey updated release of the groundwater solute transport code MT3DMS, includes new transport modeling capabilities to accommodate flow terms calculated by MODFLOW packages that were previously unsupported by MT3DMS and to provide greater flexibility in the simulation of solute transport and reactive solute transport. Unsaturated-zone transport and transport within streams and lakes, including solute exchange with connected groundwater, are among the new capabilities included in the MT3D-USGS code. MT3D-USGS also includes the capability to route a solute through dry cells that may occur in the Newton-Raphson formulation of MODFLOW (that is, MODFLOW-NWT). New chemical reaction Package options include the ability to simulate inter-species reactions and parent-daughter chain reactions. A new pump-and-treat recirculation package enables the simulation of dynamic recirculation with or without treatment for combinations of wells that are represented in the flow model, mimicking the above-ground treatment of extracted water. A reformulation of the treatment of transient mass storage improves conservation of mass and yields solutions for better agreement with analytical benchmarks. Several additional features of MT3D-USGS are (1) the separate specification of the partitioning coefficient (Kd) within mobile and immobile domains; (2) the capability to assign prescribed concentrations to the top-most active layer; (3) the change in mass storage owing to the change in water volume now appears as its own budget item in the global mass balance summary; (4) the ability to ignore cross-dispersion terms; (5) the definition of Hydrocarbon Spill-Source Package (HSS) mass loading zones using regular and irregular polygons, in addition to the currently supported circular zones; and (6) the ability to specify an absolute minimum thickness rather than the default percent minimum thickness in dry-cell circumstances.Benchmark problems that implement the new
Bedekar, Vivek; Morway, Eric D.; Langevin, Christian D.; Tonkin, Matthew J.
2016-09-30
MT3D-USGS, a U.S. Geological Survey updated release of the groundwater solute transport code MT3DMS, includes new transport modeling capabilities to accommodate flow terms calculated by MODFLOW packages that were previously unsupported by MT3DMS and to provide greater flexibility in the simulation of solute transport and reactive solute transport. Unsaturated-zone transport and transport within streams and lakes, including solute exchange with connected groundwater, are among the new capabilities included in the MT3D-USGS code. MT3D-USGS also includes the capability to route a solute through dry cells that may occur in the Newton-Raphson formulation of MODFLOW (that is, MODFLOW-NWT). New chemical reaction Package options include the ability to simulate inter-species reactions and parent-daughter chain reactions. A new pump-and-treat recirculation package enables the simulation of dynamic recirculation with or without treatment for combinations of wells that are represented in the flow model, mimicking the above-ground treatment of extracted water. A reformulation of the treatment of transient mass storage improves conservation of mass and yields solutions for better agreement with analytical benchmarks. Several additional features of MT3D-USGS are (1) the separate specification of the partitioning coefficient (Kd) within mobile and immobile domains; (2) the capability to assign prescribed concentrations to the top-most active layer; (3) the change in mass storage owing to the change in water volume now appears as its own budget item in the global mass balance summary; (4) the ability to ignore cross-dispersion terms; (5) the definition of Hydrocarbon Spill-Source Package (HSS) mass loading zones using regular and irregular polygons, in addition to the currently supported circular zones; and (6) the ability to specify an absolute minimum thickness rather than the default percent minimum thickness in dry-cell circumstances.Benchmark problems that implement the new
Burgess, Ian B; Aizenberg, Joanna; Lončar, Marko
2013-12-01
Structural hierarchy and complex 3D architecture are characteristics of biological photonic designs that are challenging to reproduce in synthetic materials. Top-down lithography allows for designer patterning of arbitrary shapes, but is largely restricted to planar 2D structures. Self-assembly techniques facilitate easy fabrication of 3D photonic crystals, but controllable defect-integration is difficult. In this paper we combine the advantages of top-down and bottom-up fabrication, developing two techniques to deposit 2D-lithographically-patterned planar layers on top of or in between inverse-opal 3D photonic crystals and creating hierarchical structures that resemble the architecture of the bright green wing scales of the butterfly, Parides sesostris. These fabrication procedures, combining advantages of both top-down and bottom-up fabrication, may prove useful in the development of omnidirectional coloration elements and 3D-2D photonic crystal devices. PMID:24263010
Burgess, Ian B; Aizenberg, Joanna; Lončar, Marko
2013-12-01
Structural hierarchy and complex 3D architecture are characteristics of biological photonic designs that are challenging to reproduce in synthetic materials. Top-down lithography allows for designer patterning of arbitrary shapes, but is largely restricted to planar 2D structures. Self-assembly techniques facilitate easy fabrication of 3D photonic crystals, but controllable defect-integration is difficult. In this paper we combine the advantages of top-down and bottom-up fabrication, developing two techniques to deposit 2D-lithographically-patterned planar layers on top of or in between inverse-opal 3D photonic crystals and creating hierarchical structures that resemble the architecture of the bright green wing scales of the butterfly, Parides sesostris. These fabrication procedures, combining advantages of both top-down and bottom-up fabrication, may prove useful in the development of omnidirectional coloration elements and 3D-2D photonic crystal devices.
NASA Astrophysics Data System (ADS)
Sass, Paul; Ritter, Oliver; Rybin, Anatolii; Batalev, Vladislav
2013-04-01
Many geodynamic processes governing intra-continental collisional orogeny are largely unexplained and controversial. A key question is the state and dynamic behaviour of the lithosphere at middle and lower crustal levels while continental collision progresses. The Pamir - Tien Shan region in Central Asia may be the best location on Earth to study such lithospheric deformation processes in situ. The mountain ranges and high plateaus formed at the tip of the north-western Indian promontory through the Cenozoic experienced rates of shortening similar to the adjacent Himalaya-Tibet system. Today, the Pamir - Tien Shan orogenic belt hosts some of the deepest active intra-continental subduction zones on Earth and absorbs the highest strain rate over the shortest distance that is manifested in the India-Asia collision zone. The multi-disciplinary Tien Shan - Pamir Geodynamic Program (TIPAGE) was designed to address some of the geodynamic key questions in this region. A magnetotelluric (MT) survey was carried out in concert with other geophysical and geological observations in Kyrgyzstan and Tajikistan, predominantly along a 350 km long and 50 km wide corridor from southern Tajikistan to Osh in Kyrgyzstan across the Pamir Plateau and southern Tien Shan mountain ranges. In total we recorded MT data at 178 stations, 26 of them combine long-period and broad band recordings. We present and compare 2D and 3D MT inversion results. Strike analysis of the data revealed an overall mean geo-electric strike direction consistent with the predominant tectonic trends. 2D inversion yields a reasonable data fit, with exception of some sites which exhibit phases above 90 degrees. 3D inversion was carried out with the ModEM package. We inverted for all four impedance tensor components and the vertical magnetic transfer functions. Topography was also included. The 3D models are generally in agreement with the 2D results but achieve a better data fit, particularly phases which could not be
NASA Astrophysics Data System (ADS)
Barnoud, Anne; Bouligand, Claire; Coutant, Olivier
2015-04-01
We linearly invert magnetic data for 3D magnetization distribution using a Bayesian methodology with a grid discretization of the space. The Bayesian approach introduces covariance matrices to regularize the ill-posed problem and overcome the non-uniqueness of the solution (Tarantola & Valette, 1982). The use of spatial covariance matrices and grid discretization leads to smooth and compact models. The algorithm provides 3D magnetization models along with resolution parameters extracted from the resolution matrix. The direct computation of the magnetic field includes the surface topography and assumes a linear relationship between rock magnetization and the magnetic field they produce. The methodology is applied to aeromagnetic data from the volcanic island of Basse-Terre in Guadeloupe, Lesser Antilles (Le Borgne & Le Mouël 1976, Le Mouël et al., 1979). Low magnetizations (a few A/m) allow linear inversion that takes into account polarity inversions of the geomagnetic field that occurred across the volcanic history of the island. Inverted magnetizations are consistent with paleomagnetic measurements on surface samples (Carlut et al., 2000 ; Samper et al., 2007). The resulting 3D model is validated against a 2D inversion performed in the Fourier domain (Parker & Huestis, 1974; Bouligand et al., 2014). The 3D distribution of magnetization helps identifying the different volcanic edifices that build the island both at the surface and up to 3 km depth.
A new model of the Arctic crustal thickness from 3D gravity inversion
NASA Astrophysics Data System (ADS)
Lebedeva-Ivanova, N. N.; Gaina, C.; Minakov, A.; Kashubin, S.
2015-12-01
The remarkable increase of new data collections and compilations for the Arctic region during the last decade motivate for a re-evaluation of our knowledge about the crustal structure and the tectonic evolution of the Arctic basins. 3D forward and inverse gravity modelling methods in the spectral domain (Minakov et al. 2012); lithosphere thermal gravity anomaly correction (Alvey et al., 2008); a vertical density variation for the sedimentary layer and lateral crustal variation density are integrated in the algorithm for derive the crustal thickness of the High Arctic region. Recently updated grids of bathymetry (Jakobsson et al., 2012), gravity anomaly (Gaina et al, 2011) and dynamic topography (Spasojevic & Gurnis, 2012) were used as input data for the algorithm. TeMAr sedimentary thickness grid (Petrov et al., 2015) was modified according to the most recent published seismic data, and was re-gridded and utilized as input data. Other input parameters for the algorithm were calibrated using seismic crustal scale profiles. Derived crustal thickness and Moho depth grids cover the area northward from 66° N and fit within a few kilometres with seismic crustal models for the most parts of the High Arctic region. Greater misfit in Moho depth between our results and seismic study (Chain & Lebedeva-Ivanova, 2015) under the northern Canada Basin suggest exceptional property of crust or/and mantel in this part of the Basin. Assumed mantle density of 3.25 kg/cm3provide the best fit for the region; it may indicate pervasive subcontinental lithospheric mantle (Goldstein et al., 2008) under the whole Arctic region. New results show a possible crustal connection between the Alpha and the Lomonosov ridges near the Canadian margin. The deepest Moho depth of c.34 km for Alpha-Mendeleev Ridge System is observed under the southern Mendeleev Ridge. The derived crustal thickness and Moho depth show a substantial improvement from the publicly available grids (CRUST1 (Laske et al., 2013
NASA Astrophysics Data System (ADS)
Meqbel, N. M.; Egbert, G. D.; Wannamaker, P. E.; Kelbert, A.; Schultz, A.
2013-12-01
Long period (10-20,000 s) magnetotelluric (MT) data are being acquired across the continental USA on a quasi-regular grid of ~70 km spacing as an electromagnetic component of the National Science Foundation EarthScope/USArray Program. These data are sensitive to fluids, melts, and other orogenic indicators, and thus provide a valuable complement to other components of EarthScope. We present and interpret results of 3-D MT data inversion from 325 sites acquired from 2006-2011 to provide a regional scale view of electrical resistivity from the middle crust to nearly the mantle transition zone, covering an area from NW Washington to NW Colorado. Extensive areas of low resistivity are imaged in the lower crust and uppermost mantle beneath the extensional provinces, most plausibly explained by underplated, hybridized magmas and associated exsolved highly saline fluids. These pervasive low resistivities show aligned or 'streaky' textures roughly parallel to seismic fast-axes, possibly reflecting widespread flow induced alignment of melt in this area. Thick sections of resistive lithosphere imaged in the eastern and northeastern part of the domain coincide spatially with the Wyoming and Medicine Hat Cratons. Sutures bounding these cratonic blocks are electrically conductive most likely due to meta-sediments emplaced during ancient collisions. Below the Cascadia forearc, the subducting Juan de Fuca and Gorda lithosphere appears highly resistive. Other resistive zones in the NW part of the domain may denote relict oceanic lithosphere: the accreted 'Siletzia' terrane beneath the Coast Ranges and Columbia Embayment, and the seismically fast 'slab curtain' beneath eastern Idaho interpreted by others as stranded Farallon lithosphere. Quasi-horizontal patches of low resistivity in the deep crust beneath the Cascade volcanic arc and fore-arc likely represent fluids evolved from breakdown of hydrous minerals in the down-going slab. In the backarc, low resistivities concentrate in
Comparison of algorithms for non-linear inverse 3D electrical tomography reconstruction.
Molinari, Marc; Cox, Simon J; Blott, Barry H; Daniell, Geoffrey J
2002-02-01
Non-linear electrical impedance tomography reconstruction algorithms usually employ the Newton-Raphson iteration scheme to image the conductivity distribution inside the body. For complex 3D problems, the application of this method is not feasible any more due to the large matrices involved and their high storage requirements. In this paper we demonstrate the suitability of an alternative conjugate gradient reconstruction algorithm for 3D tomographic imaging incorporating adaptive mesh refinement and requiring less storage space than the Newton-Raphson scheme. We compare the reconstruction efficiency of both algorithms for a simple 3D head model. The results show that an increase in speed of about 30% is achievable with the conjugate gradient-based method without loss of accuracy.
NASA Astrophysics Data System (ADS)
Brasse, Heinrich; Schäfer, Anja; Díaz, Daniel; Alvarado, Guillermo E.; Muñoz, Angélica; Mütschard, Lutz
2015-11-01
A long-period magnetotelluric (MT) experiment was conducted in early 2009 in western Nicaragua to study the electrical resistivity and thus fluid/melt distribution at the Central American continental margin where the Cocos plate subducts beneath the Caribbean plate. Strike analysis yields a preference direction perpendicular to the profile, with moderate deviation from two-dimensionality, however. Two-dimensional modeling maps the sediments of the Nicaraguan Depression and a high-conductivity zone in the mid-crust, slightly offset from the arc. Further conductors are modeled in the backarc. However, these features are probably artifacts when a 2-D program is applied to data which show moderate 3-D characteristics. 3-D inversion clarifies the situation, and the major remaining conductive structure is now quasi directly beneath the volcanic chain and interpreted as a deep-seated magma deposit. Conductivity in the backarc is also relatively high and may either be caused by still existing partial melts beneath the Paleocene to Miocene volcanic arcs or by related metallic deposits in the aureoles of hydrothermal alteration.
Laplace-domain wave-equation modeling and full waveform inversion in 3D isotropic elastic media
NASA Astrophysics Data System (ADS)
Son, Woohyun; Pyun, Sukjoon; Shin, Changsoo; Kim, Han-Joon
2014-06-01
The 3D elastic problem has not been widely studied because of the computational burden. Over the past few years, 3D elastic full waveform inversion (FWI) techniques in the time and frequency domains have been proposed by some researchers based on developments in computer science. However, these techniques still have the non-uniqueness and high nonlinearity problems. In this paper, we propose a 3D elastic FWI algorithm in the Laplace domain that can mitigate these problems. To efficiently solve the impedance matrix, we adopt a first-order absorbing boundary condition that results in a symmetric system. A conjugate gradient (CG) solver can be used because the Laplace-domain wave equation is naturally positive definite. We apply the Jacobi preconditioner to increase the convergence speed. We identify the permissible range of Laplace damping constants through dispersion analysis and accuracy tests. We perform the Laplace-domain FWI based on a logarithmic objective function, and the inversion examples are designed for a land setting, which means that the source is vertically excited and multi-component data are considered. The inversion results indicate that the inversion that uses only the vertical component performs slightly better than the multi-component inversion. This unexpected result is obtained partly because we use a vertically polarized source. We analyze the residuals and Frechet derivatives for each component to examine the characteristics of the Laplace-domain multi-component FWI. The results indicate that the residuals and Frechet derivatives for the horizontal component have a singularity problem. The numerical examples demonstrate that the singularity problem is related to the directivity of the displacement and to taking the logarithm of Laplace-domain wave fields. To avoid this singularity problem, we use a simple method that excludes the data near the singular region. Although we can use either simultaneous or sequential strategies to invert the
Electromagnetic Response Inversion for a 3D Distribution of Conductivity/Dielect
2001-10-24
NLCGCS inverts electromagnetic responses for a 3D distribution of electrical conductivity and dielectric permittivity within the earth for geophysical applications using single processor computers. The software comes bundled with a graphical user interface to aid in model construction and analysis and viewing of earth images. The solution employs both dipole and finite size source configurations for harmonic oscillatory sources. A new nonlinear preconditioner is included in the solution to speed up solution convergence.
NASA Astrophysics Data System (ADS)
Santhanam, Anand P.; Min, Yugang; Mudur, Sudhir P.; Rastogi, Abhinav; Ruddy, Bari H.; Shah, Amish; Divo, Eduardo; Kassab, Alain; Rolland, Jannick P.; Kupelian, Patrick
2010-07-01
A method to estimate the deformation operator for the 3D volumetric lung dynamics of human subjects is described in this paper. For known values of air flow and volumetric displacement, the deformation operator and subsequently the elastic properties of the lung are estimated in terms of a Green's function. A Hyper-Spherical Harmonic (HSH) transformation is employed to compute the deformation operator. The hyper-spherical coordinate transformation method discussed in this paper facilitates accounting for the heterogeneity of the deformation operator using a finite number of frequency coefficients. Spirometry measurements are used to provide values for the airflow inside the lung. Using a 3D optical flow-based method, the 3D volumetric displacement of the left and right lungs, which represents the local anatomy and deformation of a human subject, was estimated from 4D-CT dataset. Results from an implementation of the method show the estimation of the deformation operator for the left and right lungs of a human subject with non-small cell lung cancer. Validation of the proposed method shows that we can estimate the Young's modulus of each voxel within a 2% error level.
2D and 3D separate and joint inversion of airborne ZTEM and ground AMT data: Synthetic model studies
NASA Astrophysics Data System (ADS)
Sasaki, Yutaka; Yi, Myeong-Jong; Choi, Jihyang
2014-05-01
The ZTEM (Z-axis Tipper Electromagnetic) method measures naturally occurring audio-frequency magnetic fields and obtains the tipper function that defines the relationship among the three components of the magnetic field. Since the anomalous tipper responses are caused by the presence of lateral resistivity variations, the ZTEM survey is most suited for detecting and delineating conductive bodies extending to considerable depths, such as graphitic dykes encountered in the exploration of unconformity type uranium deposit. Our simulations shows that inversion of ZTEM data can detect reasonably well multiple conductive dykes placed 1 km apart. One important issue regarding ZTEM inversion is the effect of the initial model, because homogeneous half-space and (1D) layered structures produce no responses. For the 2D model with multiple conductive dykes, the inversion results were useful for locating the dykes even when the initial model was not close to the true background resistivity. For general 3D structures, however, the resolution of the conductive bodies can be reduced considerably depending on the initial model. This is because the tipper magnitudes from 3D conductors are smaller due to boundary charges than the 2D responses. To alleviate this disadvantage of ZTEM surveys, we combined ZTEM and audio-frequency magnetotelluric (AMT) data. Inversion of sparse AMT data was shown to be effective in providing a good initial model for ZTEM inversion. Moreover, simultaneously inverting both data sets led to better results than the sequential approach by enabling to identify structural features that were difficult to resolve from the individual data sets.
NASA Astrophysics Data System (ADS)
Hara, Tatsuhiko
2004-08-01
We implement the Direct Solution Method (DSM) on a vector-parallel supercomputer and show that it is possible to significantly improve its computational efficiency through parallel computing. We apply the parallel DSM calculation to waveform inversion of long period (250-500 s) surface wave data for three-dimensional (3-D) S-wave velocity structure in the upper and uppermost lower mantle. We use a spherical harmonic expansion to represent lateral variation with the maximum angular degree 16. We find significant low velocities under south Pacific hot spots in the transition zone. This is consistent with other seismological studies conducted in the Superplume project, which suggests deep roots of these hot spots. We also perform simultaneous waveform inversion for 3-D S-wave velocity and Q structure. Since resolution for Q is not good, we develop a new technique in which power spectra are used as data for inversion. We find good correlation between long wavelength patterns of Vs and Q in the transition zone such as high Vs and high Q under the western Pacific.
NASA Astrophysics Data System (ADS)
Timur, Emre
2016-04-01
There are numerous geophysical methods used to investigate geothermal areas. The major purpose of this magnetic survey is to locate the boudaries of active hydrothermal system in the South of Gediz Graben in Salihli (Manisa/Turkey). The presence of the hydrothermal system had already been inferred from surface evidence of hydrothermal activity and drillings. Firstly, 3-D prismatic models were theoretically investigated and edge detection methods were utilized with an iterative inversion method to define the boundaries and the parameters of the structure. In the first step of the application, it was necessary to convert the total field anomaly into a pseudo-gravity anomaly map. Then the geometric boudaries of the structures were determined by applying a MATLAB based software with 3 different edge detection algorithms. The exact location of the structures were obtained by using these boundary coordinates as initial geometric parameters in the inversion process. In addition to these methods, reduction to pole and horizontal gradient methods were applied to the data to achieve more information about the location and shape of the possible reservoir. As a result, the edge detection methods were found to be successful, both in the field and as theoretical data sets for delineating the boundaries of the possible geothermal reservoir structure. The depth of the geothermal reservoir was determined as 2,4 km from 3-D inversion and 2,1 km from power spectrum methods.
NASA Astrophysics Data System (ADS)
Petrov, P.; Newman, G. A.
2014-12-01
An application of the 3D elastic full-waveform inversion (FWI) to wide-aperture seismic data obtained for a complex geological setting is presented. Imaging is implemented in the Fourier domain, exploiting damped wave fields. The modeling part is solved with a finite-difference method. The non-linear conjugate gradient method is used for the inverse problem solution. The nonlinearity of FWI leads to the presence of local and multiple minima in the least-squares error functional especially for large offset problems. That leads to the shutdown of the inverse problem convergence and uncertainty in the solution. An accurate starting velocity model can avoid this problem, but in many cases may not be available. Hence other strategies are necessary to address the problem. We propose a robust inversion process for an arbitrary starting velocity model, which allows avoiding local minima and obtaining acceptable images of the deep seated structures defined by large offset data. We proceed from the assumption that decreasing data offset reduces local minima problems but decreases the depth of the recovered image. So, the inversion process is realized sequentially from small to large offsets, allowing recovery of geological structures over the entire depth range of interest from the near surface to deeper depths sensed only by large aperture offsets. Increasing of data offset is first performed at the lowest frequency and then proceeding with treatment of all data offsets from low to high frequencies. A reverse loop is also implemented in the laddering of frequencies, where after the inversion at high frequencies and all offsets we return to the lower frequencies data to continue the IP. Returning to lower frequency data provides helping to ameliorate multiple minima encountered in the inversion. The inversion then concludes by sweeping over higher frequency data, at all offsets. We demonstrate our strategies for treating wide aperture offset data on the Marmousi model, using
Development of direct-inverse 3-D methods for applied transonic aerodynamic wing design and analysis
NASA Technical Reports Server (NTRS)
Carlson, Leland A.
1989-01-01
An inverse wing design method was developed around an existing transonic wing analysis code. The original analysis code, TAWFIVE, has as its core the numerical potential flow solver, FLO30, developed by Jameson and Caughey. Features of the analysis code include a finite-volume formulation; wing and fuselage fitted, curvilinear grid mesh; and a viscous boundary layer correction that also accounts for viscous wake thickness and curvature. The development of the inverse methods as an extension of previous methods existing for design in Cartesian coordinates is presented. Results are shown for inviscid wing design cases in super-critical flow regimes. The test cases selected also demonstrate the versatility of the design method in designing an entire wing or discontinuous sections of a wing.
Aydmer, A.A.; Chew, W.C.; Cui, T.J.; Wright, D.L.; Smith, D.V.; Abraham, J.D.
2001-01-01
A simple and efficient method for large scale three-dimensional (3-D) subsurface imaging of inhomogeneous background is presented. One-dimensional (1-D) multifrequency distorted Born iterative method (DBIM) is employed in the inversion. Simulation results utilizing synthetic scattering data are given. Calibration of the very early time electromagnetic (VETEM) experimental waveforms is detailed along with major problems encountered in practice and their solutions. This discussion is followed by the results of a large scale application of the method to the experimental data provided by the VETEM system of the U.S. Geological Survey. The method is shown to have a computational complexity that is promising for on-site inversion.
Bhattacharya, Jishnu; Wolverton, C
2013-05-01
Spinel oxides represent an important class of cathode materials for Li-ion batteries. Two major variants of the spinel crystal structure are normal and inverse. The relative stability of normal and inverse ordering at different stages of lithiation has important consequences in lithium diffusivity, voltage, capacity retention and battery life. In this paper, we investigate the relative structural stability of normal and inverse structures of the 3d transition metal oxide spinels with first-principles DFT calculations. We have considered ternary spinel oxides LixM2O4 with M = Ti, V, Cr, Mn, Fe, Co and Ni in both lithiated (x = 1) and delithiated (x = 0) conditions. We find that for all lithiated spinels, the normal structure is preferred regardless of the metal. We observe that the normal structure for all these oxides has a lower size mismatch between octahedral cations compared to the inverse structure. With delithiation, many of the oxides undergo a change in stability with vanadium in particular, showing a tendency to occupy tetrahedral sites. We find that in the delithiated oxide, only vanadium ions can access a +5 oxidation state which prefers tetrahedral coordination. We have also calculated the average voltage of lithiation for these spinels. The calculated voltages agree well with the previously measured and calculated values, wherever available. For the yet to be characterized spinels, our calculation provides voltage values which can motivate further experimental attention. Lastly, we observe that all the normal spinel oxides of the 3d transition metal series have a driving force for a transformation to the non-spinel structure upon delithiation.
3D Inversion of a Self-Potential Dataset for Contaminant Detection and Mapping
NASA Astrophysics Data System (ADS)
Minsley, B. J.; Sogade, J.; Briggs, V.; Lambert, M.; Reppert, P.; Coles, D.; Morgan, F.; Rossabi, J.; Riha, B.; Shi, W.
2003-12-01
Due to the complicated nature of subsurface contaminant migration, it is difficult to determine the spatial extent and severity of contamination, which can provide essential information for efficient remediation efforts. Self-potential (SP) geophysics is employed to provide a minimally invasive, fast, and inexpensive method for remote in-situ detection and three-dimensional mapping of subsurface DNAPL (Dense Non-Aqueous Phase Liquid) in conjunction with inverse methods. The self-potential method is commonly used to detect a variety of phenomena that are typically related to thermoelectric, electrochemical, or electrokinetic coupling processes. Surface self-potential surveys have been documented to show anomalies over areas known to be contaminated, but interpretation of these datasets is often mostly qualitative, and can be plagued with problems of non-uniqueness. In this study, oxidation-reduction (redox) reactions, one of the mechanisms associated with the attenuation of chemicals released into the environment, provide an electrochemical source for the SP signal. Electrochemical potentials associated with subsurface zones of redox activity are analogous to localized 'batteries' buried within native earth materials, and produce an electric field that is remotely detected using electrodes placed at the surface and in nearby boreholes. Three-dimensional inversion of the self-potential data incorporating resistivity information is the necessary step in characterizing the source parameters, which are directly related to the redox activity, and therefore to the contaminant itself. Surface and borehole SP data are collected in order to help constrain the solution in depth, and resistivity information is taken from an induced polarization survey performed over the same area during this field excursion. Inversion results are correlated with contaminant concentration data sampled from a series of ground-truth boreholes within the region of interest.
Development of direct-inverse 3-D methods for applied transonic aerodynamic wing design and analysis
NASA Technical Reports Server (NTRS)
Carlson, Leland A.
1989-01-01
Progress in the direct-inverse wing design method in curvilinear coordinates has been made. This includes the remedying of a spanwise oscillation problem and the assessment of grid skewness, viscous interaction, and the initial airfoil section on the final design. It was found that, in response to the spanwise oscillation problem that designing at every other spanwise station produced the best results for the cases presented, a smoothly varying grid is especially needed for the accurate design at the wing tip, the boundary layer displacement thicknesses must be included in a successful wing design, the design of high and medium aspect ratio wings is possible with this code, and the final airfoil section designed is fairly independent of the initial section.
Barlebo, H.C.; Rosbjerg, D.; Hill, M.C.
1996-01-01
An extensive amount of data including hydraulic heads, hydraulic conductivities and concentrations of several solutes from controlled injections have been collected during the MADE 1 and MADE 2 experiments at a heterogeneous site near Columbus, Mississippi. In this paper the use of three-dimensional inverse groundwater models including simultaneous estimation of flow and transport parameters is proposed to help identify the dominant characteristics at the site. Simulations show that using a hydraulic conductivity distribution obtained from 2187 borehole flowmeter tests directly in the model produces poor matches to the measured hydraulic heads and tritium concentrations. Alternatively, time averaged hydraulic head maps are used to define zones of constant hydraulic conductivity to be estimated. Preliminary simulations suggest that in the case of conservative transport many, but not all, of the major plume characteristics can be explained by large-scale heterogeneity in recharge and hydraulic conductivity.
Brosten, T.R.; Day-Lewis, F. D.; Schultz, G.M.; Curtis, G.P.; Lane, J.W.
2011-01-01
Electromagnetic induction (EMI) instruments provide rapid, noninvasive, and spatially dense data for characterization of soil and groundwater properties. Data from multi-frequency EMI tools can be inverted to provide quantitative electrical conductivity estimates as a function of depth. In this study, multi-frequency EMI data collected across an abandoned uranium mill site near Naturita, Colorado, USA, are inverted to produce vertical distribution of electrical conductivity (EC) across the site. The relation between measured apparent electrical conductivity (ECa) and hydraulic conductivity (K) is weak (correlation coefficient of 0.20), whereas the correlation between the depth dependent EC obtained from the inversions, and K is sufficiently strong to be used for hydrologic estimation (correlation coefficient of -0.62). Depth-specific EC values were correlated with co-located K measurements to develop a site-specific ln(EC)-ln(K) relation. This petrophysical relation was applied to produce a spatially detailed map of K across the study area. A synthetic example based on ECa values at the site was used to assess model resolution and correlation loss given variations in depth and/or measurement error. Results from synthetic modeling indicate that optimum correlation with K occurs at ~0.5m followed by a gradual correlation loss of 90% at 2.3m. These results are consistent with an analysis of depth of investigation (DOI) given the range of frequencies, transmitter-receiver separation, and measurement errors for the field data. DOIs were estimated at 2.0??0.5m depending on the soil conductivities. A 4-layer model, with varying thicknesses, was used to invert the ECa to maximize available information within the aquifer region for improved correlations with K. Results show improved correlation between K and the corresponding inverted EC at similar depths, underscoring the importance of inversion in using multi-frequency EMI data for hydrologic estimation. ?? 2011.
Coordinate transformation method for the solution of inverse problem in 2D and 3D scatterometry
NASA Astrophysics Data System (ADS)
Ponnusamy, Sekar
2005-05-01
For scatterometry applications, diffraction analysis of gratings is carried out by using Rigorous Coupled Wave Analysis (RCWA). Though RCWA method is originally developed for lamellar gratings, arbitrary profiles can be analyzed using staircase approximation with S-Matrix propagation of field components. For improved accuracy, more number of Fourier waves need to be included in Floquet-Bloch expansion of the field components and also more number of slices are to be made in staircase approximation. These requirements increase the time required for the analysis. A coordinate transformation method (CTM) developed by Chandezon et. al renders the arbitrary grating profile into a plane surface in the new coordinate system and hence it does not require slicing. This method is extended to 3D structures by several authors notably, by Harris et al for non-orthogonal unit cells and by Granet for correct Fourier expansion. Also extended is to handle sharp-edged gratings through adaptive spatial resolution. In this paper, an attempt is made to employ CTM with correct Fourier expansion in conjunction with adaptive spatial resolution, for scatterometry applications. A MATLAB program is developed, and thereby, demonstrated that CTM can be used for diffraction analysis of trapezoidal profiles that are typically encountered in scatterometry applications.
Crustal Structure of the Flood Basalt Province of Ethiopia from Constrained 3-D Gravity Inversion
NASA Astrophysics Data System (ADS)
Mammo, Tilahun
2013-12-01
The Oligocene Afar mantle plume resulted in the eruption of a large volume of basaltic magma, including major sequences of rhyolitic ignimbrites, in a short span of time across Ethiopia. In order to assess the impact of these magmatic processes on the crust and to investigate the general crustal configuration beneath the Ethiopian plateau, northern part of the Main Ethiopian Rift and the Afar depression, analysis and modeling of the gravity field have been conducted. The Bouguer gravity map is dominated by long-wavelength anomalies that primarily arise from the isostatic compensation of the topography. Consequently, anomalies within the crust/upper mantle are masked and quantitative interpretation becomes difficult. The long-wavelength anomalies are approximated using admittance technique and subsequently removed from the Bouguer anomalies to obtain the residual isostatic anomalies. The residual map contains both short- and intermediate-wavelength anomalies related to geologic and tectonic features. The long-wavelength regional isostatic field is used to map the crust-mantle interface and the results are in good agreement with those determined by other geophysical methods. Seismic constrained gravity inversion was performed on the isostatic residual field and series of three-dimensional models have been constructed for the structures of the crust and upper mantle beneath the uplifted and rifted flood basalt province of northern Ethiopia. The inversion results have shown that the NW plateau has thick crust that rests on normal lithospheric mantle. Afar, On the other hand, is marked by thin stretched crust resting on a low-density upper mantle indicating a hotter thermal regime and partial melt. No lithospheric mantle is observed beneath Afar. The models further indicate the presence of an extensive sub-crustal thick (~12 km on average) and high-density (~3.06 gm/cc) mafic accreted igneous layer of fractionated cumulate (magmatic underplating) beneath the NW plateau
NASA Astrophysics Data System (ADS)
Götze, Hans-Jürgen; Choi, Sungchan
2015-04-01
We combined the global gravity dataset EGM2008 and a local terrestrial gravity data survey to conduct constrained 3-D crustal density modeling of a strato-volcanic complex and the surrounding area located close to the border of North Korea and China. The independent geophysical (seismic, seismology, geochemistry) and petrological constraints will be presented together with the preprocessing of data base by curvature analysis and Euler deconvolution. The multiple data base is used to assist a general interpretation of the investigated area, and the 3D density model (modelled by the in-house IGMAS+ software). Mt. Paekdu is characterized by a low of Bouguer anomaly of some -110 × 10-5 m/s2, which is caused by the combined gravity effects of (1) Moho depth of about 40 km, (2) a zone with both lower P-wave velocity and density than the surrounding, (3) low density volcanic rocks at the surface, and (4) the presence of a magma chamber that has not previously been identified. The terrestrial gravity field measured along the seismic profile shows a remarkable anomaly descending from the southern- to the northern flank of the Mt. Paekdu volcano, which should be a typical anomaly pattern generally observed over the active volcanic area in the world (e.g. the Yellow Stone volcano). The trend is interpreted to be caused by a prominent density difference between a serious of high density mid crustal sill beneath the southern flank and a predicted partial melted zone locating in the northern flank. With the help of several geoscientific observations (seismic, electromagnetic, gravity and geochemistry) and the 3D density model we conclude that a high density sill was formed in Pliocene and early Pleistocene after pre-shield plateau-forming eruption. Since the Pliocene, volcanic activity in the Mt. Paekdu region might be migrated from the southeastern of North Korea to the northwest, following the path of NW-SE-trending faults. Recently observed seismic tremors can be explained
NASA Astrophysics Data System (ADS)
Goetze, H. J.; Choi, S.
2014-12-01
In the presentation we get use of the global gravity dataset EGM2008 and a local terrestrial gravity data survey for a constrained 3-D crustal density modeling of a stratovolcano and its surrounding area located close to the border of North Korea and China. The independent geophysical (seismic, seismology, geochemistry) and petrological constraints will be presented together with the preprocessing of data base by curvature analysis and Euler deconvolution. The multiple data base is used to assist a general interpretation of the investigated area in time, and the 3D density model (modelled by the inhouse IGMAS+ software). Mt. Paekdu is characterized by a low of Bouguer anomaly of some -110 ´ 10-5 m/s2, which is caused by the combined gravity effects of (1) Moho depth of about 40 km, (2) a zone with both lower P-wave velocity and density than the surrounding, (3) low density volcanic rocks at the surface, and (4) the presence of a magma chamber that has not previously been identified. The terrestrial gravity field measured along the seismic profile shows a remarkable anomaly descending from the southern- to the northern flank of the Mt. Paekdu volcano, which should be a typical anomaly pattern generally obsered over the active volcanic area in the world (e.g. the Yellow Stone volcano). The trend is interpreted to be caused by a prominent density difference between a serious of high density mid crustal sill beneath the southern flank and a predicted partial melted zone locating in the northern flank. With the help of several geoscientific observations (seismic, electromagnetic, gravity and geochemistry) and the 3D density model we conclude that a high density sill was formed in Pliocene and early Pleistocene after pre-shield plateau-forming eruption. Since the Pliocene, volcanic activity in the Mt. Paekdu region might be migrated from the southeastern of North Korea to the northwest, following the path of NW-SE-trending faults. Recently observed seismic tremors can
MT2DInvMatlab—A program in MATLAB and FORTRAN for two-dimensional magnetotelluric inversion
NASA Astrophysics Data System (ADS)
Lee, Seong Kon; Kim, Hee Joon; Song, Yoonho; Lee, Choon-Ki
2009-08-01
MT2DInvMatlab is an open-source MATLAB® software package for two-dimensional (2D) inversion of magnetotelluric (MT) data; it is written in mixed languages of MATLAB and FORTRAN. MT2DInvMatlab uses the finite element method (FEM) to compute 2D MT model responses, and smoothness-constrained least-squares inversion with a spatially variable regularization parameter algorithm to stabilize the inversion process and provide a high-resolution optimal earth model. It is also able to include terrain effects in inversion by incorporating topography into a forward model. This program runs under the MATLAB environment so that users can utilize the existing general interface of MATLAB, while some specific functions are written in FORTRAN 90 to speed up computation and reuse pre-existing FORTRAN code in the MATLAB environment with minimal modification. This program has been tested using synthetic models, including one with variable topography, and on field data. The results were assessed by comparing inverse models obtained with MT2DInvMatlab and with a non-linear conjugate gradient (NLCG) algorithm. In both tests the new inversion software reconstructs the subsurface resistivity structure very closely and provides an improvement in both resolution and stability.
NASA Astrophysics Data System (ADS)
Jesús Moral García, Francisco; Rebollo Castillo, Francisco Javier; Monteiro Santos, Fernando
2016-04-01
Maps of apparent electrical conductivity of the soil are commonly used in precision agriculture to indirectly characterize some important properties like salinity, water, and clay content. Traditionally, these studies are made through an empirical relationship between apparent electrical conductivity and properties measured in soil samples collected at a few locations in the experimental area and at a few selected depths. Recently, some authors have used not the apparent conductivity values but the soil bulk conductivity (in 2D or 3D) calculated from measured apparent electrical conductivity through the application of an inversion method. All the published works used data collected with electromagnetic (EM) instruments. We present a new software to invert the apparent electrical conductivity data collected with VERIS 3100 and 3150 (or the more recent version with three pairs of electrodes) using the 1D spatially constrained inversion method (1D SCI). The software allows the calculation of the distribution of the bulk electrical conductivity in the survey area till a depth of 1 m. The algorithm is applied to experimental data and correlations with clay and water content have been established using soil samples collected at some boreholes. Keywords: Digital soil mapping; inversion modelling; VERIS; soil apparent electrical conductivity.
NASA Astrophysics Data System (ADS)
Oh, Ju-Won; Alkhalifah, Tariq
2016-07-01
Multi-parameter 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 multi component sensors, the potential for tradeoff 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.
NASA Astrophysics Data System (ADS)
Oh, Ju-Won; Alkhalifah, Tariq
2016-09-01
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.
NASA Astrophysics Data System (ADS)
Macquet, M.; Paul, A.; Pedersen, H.
2013-12-01
Barmin et al. (2001). The last step of our tomography is the inversion of local group velocity dispersion curves for the 3-D Vs structure. For this step, we carried out a combination of full non-linear inversion and linearized inversion. This combination is motivated by the strong lateral variation in seismic structure beneath the array, ranging from deep sedimentary basins to the Pyrenees mountain range. During the first step, we fully explore a ~2 700 000 models library averaging the 200 best fitting models to build an input model. We then use this average as input for a linearized inversion using the program package of Herrnann and Ammon (2002). This method makes it possibly to automatically and consistently build a 3-D Vs model in spite of the lateral variations of seismic structure.
1D nanorod-planted 3D inverse opal structures for use in dye-sensitized solar cells.
Park, Yesle; Lee, Jung Woo; Ha, Su-Jin; Moon, Jun Hyuk
2014-03-21
The effectiveness of the 1D nanorod (NR)-planted 3D inverse opal (IO) structure as an electrode for dye-sensitized solar cells (DSSCs) is demonstrated here. The NRs were grown on the surface of a macroporous IO structure and their longitudinal growth increased the surface area of the structure proportional to the growth duration. NR/IO electrodes with various NR growth times were compared. A remarkable JSC was obtained for the DSSCs utilizing a NR/IO electrode. The improvement of the JSC was analyzed in terms of its efficiency in light harvesting and electron transport. The growth of the NRs improved the dye adsorption density and scattering property of the electrode, resulting in an improvement in the light harvesting efficiency. Electrochemical impedance analysis revealed that the NRs also improved its electron transport properties. Further growth of the NRs tended to limit the increase of the JSC, which could be attributed to an overlap between them. PMID:24356878
Horie, Tomohiko; Kawakata, Mami; Kajihara, Nao; Takano, Hayato; Honda, Masatoshi; Muro, Isao; Ogino, Tetsuo
2011-01-01
The purpose of this study was to improve the visualization of long-axis black-blood imaging of the carotid arteries. We experimented on phantom and in-vivo study of 3 dimension (3D) inversion recovery T(1) turbo field echo combined with phase sensitive inversion recovery (PSIR-3D IR-T(1)TFE) at 3.0 Tesla. As a result, the contrast has been improved by calculated images of PSIR-3D IR-T(1)TFE set to inversion time (TI) 350 ms that is shorter than null point of blood. This displays that the contrast between blood and tissues can be improved when the longitudinal magnetization of blood is a negative. Therefore, the visualization of long-axis black-blood imaging of the carotid arteries has been improved by the calculated images of PSIR-3D IR-T(1)TFE set to TI that is shorter than null point of blood.
NASA Astrophysics Data System (ADS)
Windhari, Ayuty; Handayani, Gunawan
2015-04-01
The 3D inversion gravity anomaly to estimate topographical density using a matlab source code from gridded data provided by Parker Oldenburg algorithm based on fast Fourier transform was computed. We extend and improved the source code of 3DINVERT.M invented by Gomez Ortiz and Agarwal (2005) using the relationship between Fourier transform of the gravity anomaly and the sum of the Fourier transform from the topography density. We gave density contrast between the two media to apply the inversion. FFT routine was implemented to construct amplitude spectrum to the given mean depth. The results were presented as new graphics of inverted topography density, the gravity anomaly due to the inverted topography and the difference between the input gravity data and the computed ones. It terminates when the RMS error is lower than pre-assigned value used as convergence criterion or until maximum of iterations is reached. As an example, we used the matlab program on gravity data of Banten region, Indonesia.
NASA Astrophysics Data System (ADS)
Choi, S.; Kim, C.; Kim, H. R.; Park, C.; Park, H. Y.
2015-12-01
We performed the marine magnetic and the bathymetry survey in the Lau basin for finding the submarine hydrothermal deposits in October 2009. We acquired magnetic and bathymetry datasets by using Overhouser Proton Magnetometer SeaSPY(Marine Magnetics Co.) and Multi-Beam Echo Sounder EM120(Kongsberg Co.). We conducted the data processing to obtain detailed seabed topography, magnetic anomaly and reduction to the pole(RTP). The Lau basin is one of the youngest back-arc basins in the Southwest Pacific. This region was a lot of hydrothermal activities and hydrothermal deposits. In particular, Tofua Arc(TA) in the Lau basin consists of various and complex stratovolcanos(from Massoth et al., 2007).), We calculated the magnetic susceptibility distribution of the TA19-1 seamount(longitude:176°23.5'W, latitude: 22°42.5'W)area using the RTP data by 3-D magnetic inversion from Jung's previous study(2013). Based on 2D 'compact gravity inversion' by Last & Kubik(1983), we expend it to the 3D algorithm using iterative reweighted least squares method with some weight matrices. The used weight matrices are two types: 1) the minimum gradient support(MGS) that controls the spatial distribution of the solution from Porniaguine and Zhdanov(1999); 2) the depth weight that are used according to the shape of subsurface structures. From the modeling, we derived the appropriate scale factor for the use of depth weight and setting magnetic susceptibility. Furthermore, we have to enter a very small error value to control the computation of the singular point of the inversion model that was able to be easily calculated for modeling. In addition, we applied separately weighted value for the correct shape and depth of the magnetic source. We selected the best results model by change to converge of RMS. Compared between the final modeled result and RTP values in this study, they are generally similar to the each other. But the input values and the modeled values have slightly little difference
NASA Astrophysics Data System (ADS)
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.
NASA Astrophysics Data System (ADS)
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.
Modeling Coastal Salinity in Quasi 2D and 3D Using a DUALEM-421 and Inversion Software.
Davies, Gareth; Huang, Jingyi; Monteiro Santos, Fernando Acacio; Triantafilis, John
2015-01-01
Rising sea levels, owing to climate change, are a threat to fresh water coastal aquifers. This is because saline intrusions are caused by increases and intensification of medium-large scale influences including sea level rise, wave climate, tidal cycles, and shifts in beach morphology. Methods are therefore required to understand the dynamics of these interactions. While traditional borehole and galvanic contact resistivity (GCR) techniques have been successful they are time-consuming. Alternatively, frequency-domain electromagnetic (FEM) induction is potentially useful as physical contact with the ground is not required. A DUALEM-421 and EM4Soil inversion software package are used to develop a quasi two- (2D) and quasi three-dimensional (3D) electromagnetic conductivity images (EMCI) across Long Reef Beach located north of Sydney Harbour, New South Wales, Australia. The quasi 2D models discern: the dry sand (<10 mS/m) associated with the incipient dune; sand with fresh water (10 to 20 mS/m); mixing of fresh and saline water (20 to 500 mS/m), and; saline sand of varying moisture (more than 500 mS/m). The quasi 3D EMCIs generated for low and high tides suggest that daily tidal cycles do not have a significant effect on local groundwater salinity. Instead, the saline intrusion is most likely influenced by medium-large scale drivers including local wave climate and morphology along this wave-dominated beach. Further research is required to elucidate the influence of spring-neap tidal cycles, contrasting beach morphological states and sea level rise.
Modeling Coastal Salinity in Quasi 2D and 3D Using a DUALEM-421 and Inversion Software.
Davies, Gareth; Huang, Jingyi; Monteiro Santos, Fernando Acacio; Triantafilis, John
2015-01-01
Rising sea levels, owing to climate change, are a threat to fresh water coastal aquifers. This is because saline intrusions are caused by increases and intensification of medium-large scale influences including sea level rise, wave climate, tidal cycles, and shifts in beach morphology. Methods are therefore required to understand the dynamics of these interactions. While traditional borehole and galvanic contact resistivity (GCR) techniques have been successful they are time-consuming. Alternatively, frequency-domain electromagnetic (FEM) induction is potentially useful as physical contact with the ground is not required. A DUALEM-421 and EM4Soil inversion software package are used to develop a quasi two- (2D) and quasi three-dimensional (3D) electromagnetic conductivity images (EMCI) across Long Reef Beach located north of Sydney Harbour, New South Wales, Australia. The quasi 2D models discern: the dry sand (<10 mS/m) associated with the incipient dune; sand with fresh water (10 to 20 mS/m); mixing of fresh and saline water (20 to 500 mS/m), and; saline sand of varying moisture (more than 500 mS/m). The quasi 3D EMCIs generated for low and high tides suggest that daily tidal cycles do not have a significant effect on local groundwater salinity. Instead, the saline intrusion is most likely influenced by medium-large scale drivers including local wave climate and morphology along this wave-dominated beach. Further research is required to elucidate the influence of spring-neap tidal cycles, contrasting beach morphological states and sea level rise. PMID:25053423
3D structural cartography based on magnetic and gravity data inversion - Case of South-West Algeria
NASA Astrophysics Data System (ADS)
Hichem, Boubekri; Mohamed, Hamoudi; Abderrahmane, Bendaoud; Ivan, Priezzhev; Karim, Allek
2015-12-01
This article presents the results of 3D aeromagnetic and gravity data inversion across the West African Craton (WAC) in South West Algeria. Although the used data have different origins and resolutions, the performed manual and automatic interpretation for each dataset shows a good correlation with some earlier geological studies of the region, major structural aspects of the locality, as well as other new structural features. Many curved faults parallel to the suture zone indicate the presence of terranes or the metacratonization of the WAC and a related fault network of great importance with NE-SW and NW-SE directions. The mega shear zones from north to south, which are visible at the surface in the Hoggar, are also observed along the Saharan Platform. The fact that these faults are observed since the Cambro-Ordovician in all crust (including the Saharan Basins) indicates that this area, which is situated on the border of the WAC, remained active during the entire period of time.
NASA Astrophysics Data System (ADS)
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.
NASA Astrophysics Data System (ADS)
Kuvshinov, Alexey; Semenov, Alexey
2012-06-01
We present a novel frequency-domain inverse solution to recover the 3-D electrical conductivity distribution in the mantle. The solution is based on analysis of local C-responses. It exploits an iterative gradient-type method - limited-memory quasi-Newton method - for minimizing the penalty function consisting of data misfit and regularization terms. The integral equation code is used as a forward engine to calculate responses and data misfit gradients during inversion. An adjoint approach is implemented to compute misfit gradients efficiently. Further improvements in computational load come from parallelizing the scheme with respect to frequencies, and from setting the most time-consuming part of the forward calculations - calculation of Green's tensors - apart from the inversion loop. Convergence, performance, and accuracy of our 3-D inverse solution are demonstrated with a synthetic numerical example. A companion paper applies the strategy set forth here to real data.
NASA Astrophysics Data System (ADS)
Trovato, C.; Lokmer, I.; De Martin, F.; Aochi, H.
2016-11-01
Since a few decades volcanic long period (LP) events have been recorded on many active volcanoes and their study has been recognized as an important tool to characterize volcanic activity. LP event analyses through moment tensor (MT) inversions have led to kinematic descriptions of various source mechanisms. The main challenge in these inversions is to `strip out' the propagation effect in order to isolate the source; hence the velocity model used controls the accuracy of the retrieved source mechanism. We first carry out several synthetic tests of inversions on Mt Etna volcano (Italy). Four geological models with topography are considered with increasing complexity: the most complex model is used to generate synthetic data, while the other three models are used to calculate the Green's functions for inversions. The retrieved solutions from the three velocity models are similar. The MT solutions for a deeper source are well retrieved, while a shallower source test suffers from high uncertainties and strong misinterpretation of the source orientation. The homogeneous model gives the lowest misfit value, but source location and mechanism decomposition are inaccurate. When a complex model different from the true one is used, a high misfit value and a wrong solution is obtained. We then incorporate our findings into the MT inversion of an LP event recorded on Mt Etna in 2008. We obtain very different solutions among the three models in terms of source location and mechanism decomposition. The overall shape of the retrieved source time functions are similar, but some amplitude differences arise, especially for the homogeneous model. Our work highlights the importance of including the unconsolidated surface materials in the computation of Green's functions especially when dealing with shallow sources.
Weng Cho Chew
2004-10-27
The project aim was the improvement, evaluation, and application of one dimensional (1D) inversion and development and application of three dimensional (3D) inversion to processing of data collected at waste pits at the Idaho National Engineering and Environmental Laboratory. The inversion methods were intended mainly for the Very Early Time Electromagnetic (VETEM) system which was designed to improve the state-of-the-art of electromagnetic imaging of the shallow (0 to about 5m) subsurface through electrically conductive soils.
NASA Astrophysics Data System (ADS)
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.
Commer, Michael; Helwig, Stefan, L.; Hordt, Andreas; Scholl,Carsten; Tezkan, Bulent
2006-06-14
Three long-offset transient electromagnetic (LOTEM) surveyswerecarried out at the active volcano Merapi in Central Java (Indonesia)during the years 1998, 2000, and 2001. The measurements focused on thegeneral resistivity structure of the volcanic edifice at depths of 0.5-2km and the further investigation of a southside anomaly. The measurementswere insufficient for a full 3D inversion scheme, which could enable theimaging of finely discretized resistivity distributions. Therefore, astable, damped least-squares joint-inversion approach is used to optimize3D models with a limited number of parameters. The mode ls feature therealistic simulation of topography, a layered background structure, andadditional coarse 3D blocks representing conductivity anomalies.Twenty-eight LOTEM transients, comprising both horizontal and verticalcomponents of the magnetic induction time derivative, were analyzed. Inview of the few unknowns, we were able to achieve reasonable data fits.The inversion results indicate an upwelling conductor below the summit,suggesting hydrothermal activity in the central volcanic complex. Ashallow conductor due to a magma-filled chamber, at depths down to 1 kmbelow the summit, suggested by earlier seismic studies, is not indicatedby the inversion results. In conjunction with an anomalous-density model,derived from arecent gravity study, our inversion results provideinformation about the southern geological structure resulting from amajor sector collapse during the Middle Merapi period. The density modelallows to assess a porosity range andthus an estimated vertical salinityprofile to explain the high conductivities on a larger scale, extendingbeyond the foothills of Merapi.
NASA Astrophysics Data System (ADS)
Barnoud, A.; Coutant, O.; Bouligand, C.
2013-12-01
We propose to use a Bayesian methodology combined with a grid node discretization to invert linearly for 3D density distributions. The inversion and the forward modeling are derived from seismological travel-time inversion techniques in order to facilitate joint inversion or interpretation of density and seismic velocity models. The Bayesian method (Tarantola, 2005) introduces covariance matrices to regularize this ill-posed problem and reduce the non-uniqueness of the solution. Spatial covariances and grid discretization favor smooth and compact solutions that compare to usual seismic tomographic results. Compared to similar approaches our development includes i) the computation of the gravity field for linear vertical gradients and layers, including surface topography, a standard model description in seismology, ii) an explicit formulation of the a-priori covariance matrix. This last point allows to easily modify the spatial a-priori covariance (or scale, or wavelength) and hence, to perform successive linear inversions at different wavelengths. A series of synthetic tests is performed for validation, and used to show the advantage and limitation of this methodology. The method is appropriate for crustal and volcanological area studies, and allows a natural coupling with seismological inversions (Coutant et al., 2012). We present here two case studies for 3D gravity inversions. First, the inversion is performed in a crustal alpine context, the area of the well studied Ivrea Body in Italy. Secondly, we apply the inversion to gravity data from the volcanic island of Basse-Terre whose internal structure is badly constrained. We use data from previous studies supplemented with new high quality data acquired in 2012 within the frame of the Domoscan project. A 3D density model of the island of Basse-Terre is derived for the first time.
NASA Astrophysics Data System (ADS)
Lebedeva-Ivanova, Nina; Gaina, Carmen; Minakov, Alexander; Kashubin, Sergey
2016-04-01
We derived Moho depth and crustal thickness for the High Arctic region by 3D forward and inverse gravity modelling method in the spectral domain (Minakov et al. 2012) using lithosphere thermal gravity anomaly correction (Alvey et al., 2008); a vertical density variation for the sedimentary layer and lateral crustal variation density. Recently updated grids of bathymetry (Jakobsson et al., 2012), gravity anomaly (Gaina et al, 2011) and dynamic topography (Spasojevic & Gurnis, 2012) were used as input data for the algorithm. TeMAr sedimentary thickness grid (Petrov et al., 2013) was modified according to the most recently published seismic data, and was re-gridded and utilized as input data. Other input parameters for the algorithm were calibrated using seismic crustal scale profiles. The results are numerically compared with publically available grids of the Moho depth and crustal thickness for the High Arctic region (CRUST 1 and GEMMA global grids; the deep Arctic Ocean grids by Glebovsky et al., 2013) and seismic crustal scale profiles. The global grids provide coarser resolution of 0.5-1.0 geographic degrees and not focused on the High Arctic region. Our grids better capture all main features of the region and show smaller error in relation to the seismic crustal profiles compare to CRUST 1 and GEMMA grids. Results of 3D gravity modelling by Glebovsky et al. (2013) with separated geostructures approach show also good fit with seismic profiles; however these grids cover the deep part of the Arctic Ocean only. Alvey A, Gaina C, Kusznir NJ, Torsvik TH (2008). Integrated crustal thickness mapping and plate recon-structions for the high Arctic. Earth Planet Sci Lett 274:310-321. Gaina C, Werner SC, Saltus R, Maus S (2011). Circum-Arctic mapping project: new magnetic and gravity anomaly maps of the Arctic. Geol Soc Lond Mem 35, 39-48. Glebovsky V.Yu., Astafurova E.G., Chernykh A.A., Korneva M.A., Kaminsky V.D., Poselov V.A. (2013). Thickness of the Earth's crust in the
Kim, Hye-Na; Yoo, Haemin; Moon, Jun Hyuk
2013-05-21
We demonstrated the preparation of graphene-embedded 3D inverse opal electrodes for use in DSSCs. The graphene was incorporated locally into the top layers of the inverse opal structures and was embedded into the TiO2 matrix via post-treatment of the TiO2 precursors. DSSCs comprising the bare and 1-5 wt% graphene-incorporated TiO2 inverse opal electrodes were compared. We observed that the local arrangement of graphene sheets effectively enhanced electron transport without significantly reducing light harvesting by the dye molecules. A high efficiency of 7.5% was achieved in DSSCs prepared with the 3 wt% graphene-incorporated TiO2 inverse opal electrodes, constituting a 50% increase over the efficiencies of DSSCs prepared without graphene. The increase in efficiency was mainly attributed to an increase in J(SC), as determined by the photovoltaic parameters and the electrochemical impedance spectroscopy analysis. PMID:23536037
Kim, Hye-Na; Yoo, Haemin; Moon, Jun Hyuk
2013-05-21
We demonstrated the preparation of graphene-embedded 3D inverse opal electrodes for use in DSSCs. The graphene was incorporated locally into the top layers of the inverse opal structures and was embedded into the TiO2 matrix via post-treatment of the TiO2 precursors. DSSCs comprising the bare and 1-5 wt% graphene-incorporated TiO2 inverse opal electrodes were compared. We observed that the local arrangement of graphene sheets effectively enhanced electron transport without significantly reducing light harvesting by the dye molecules. A high efficiency of 7.5% was achieved in DSSCs prepared with the 3 wt% graphene-incorporated TiO2 inverse opal electrodes, constituting a 50% increase over the efficiencies of DSSCs prepared without graphene. The increase in efficiency was mainly attributed to an increase in J(SC), as determined by the photovoltaic parameters and the electrochemical impedance spectroscopy analysis.
NASA Astrophysics Data System (ADS)
Tiercelin, J.; Abdelfettah, Y.; Tarits, P.; Hautot, S.
2012-12-01
Combining data of different geophysical methods is more and more used to propose an accurate geological models. Joint inversion technique is a quantitative approach to inverse more than one parameter in the same inversion run. Many authors noted that the joint inversion reduce the number of acceptable model and offer a better final geological models. This kind of inversion is motivated by the limitations of each geophysical method. In this way, we applied 2-D magnetotelluric (MT) and gravity joint inversion on real MT and gravity data acquired in Turkana area, in order to understand the vertical stratigraphy of the west end of Turkana basin. The geology is comprised of thick basalt layers on top of sandstones and bedrock. Seismic studies suggested the presence of Paleogene sediments underneath the sandstones but this still remains uncertain because of the poor data quality due to the important basaltic cover. The final resistivity and density models obtained by joint inversion approach confirm the previous results obtained mainly by seismic reflection, and reveal new features under the Turkana volcanic formation. The geometry of the basins is well recovered where it is dominated by a half-graben structures. The thickness of the Miocene - Holocene sediments in the top is well identified, and its limits with the Turkana volcanics is also well identified. It is comparable with the limit showed by seismic interpretation presented recently, and which is localized on the same profile. The horizontal and vertical variations of the Turkana volcanics, the Lappur sandstones, and the basement is well revealed. A conceptual geological models are proposed under three profiles. It is build mainly by the combination of the density and the resistivity interpretations, as well as the geological knowledge available, which is derived mainly by the outcrop rocks study in Turkana and Kachoda basins.
Bao Yidong; Hu Sibo; Lang Zhikui; Hu Ping
2005-08-05
A fast simulation scheme for 3D curved binder flanging and blank shape prediction of sheet metal based on one-step inverse finite element method is proposed, in which the total plasticity theory and proportional loading assumption are used. The scheme can be actually used to simulate 3D flanging with complex curve binder shape, and suitable for simulating any type of flanging model by numerically determining the flanging height and flanging lines. Compared with other methods such as analytic algorithm and blank sheet-cut return method, the prominent advantage of the present scheme is that it can directly predict the location of the 3D flanging lines when simulating the flanging process. Therefore, the prediction time of flanging lines will be obviously decreased. Two typical 3D curve binder flanging including stretch and shrink characters are simulated in the same time by using the present scheme and incremental FE non-inverse algorithm based on incremental plasticity theory, which show the validity and high efficiency of the present scheme.
NASA Astrophysics Data System (ADS)
Morgan, Joanna; Warner, Michael; Arnoux, Gillean; Hooft, Emilie; Toomey, Douglas; VanderBeek, Brandon; Wilcock, William
2016-02-01
3-D full-waveform inversion (FWI) is an advanced seismic imaging technique that has been widely adopted by the oil and gas industry to obtain high-fidelity models of P-wave velocity that lead to improvements in migrated images of the reservoir. Most industrial applications of 3-D FWI model the acoustic wavefield, often account for the kinematic effect of anisotropy, and focus on matching the low-frequency component of the early arriving refractions that are most sensitive to P-wave velocity structure. Here, we have adopted the same approach in an application of 3-D acoustic, anisotropic FWI to an ocean-bottom-seismometer (OBS) field data set acquired across the Endeavour oceanic spreading centre in the northeastern Pacific. Starting models for P-wave velocity and anisotropy were obtained from traveltime tomography; during FWI, velocity is updated whereas anisotropy is kept fixed. We demonstrate that, for the Endeavour field data set, 3-D FWI is able to recover fine-scale velocity structure with a resolution that is 2-4 times better than conventional traveltime tomography. Quality assurance procedures have been employed to monitor each step of the workflow; these are time consuming but critical to the development of a successful inversion strategy. Finally, a suite of checkerboard tests has been performed which shows that the full potential resolution of FWI can be obtained if we acquire a 3-D survey with a slightly denser shot and receiver spacing than is usual for an academic experiment. We anticipate that this exciting development will encourage future seismic investigations of earth science targets that would benefit from the superior resolution offered by 3-D FWI.
NASA Astrophysics Data System (ADS)
Gao, J.; Zhang, H.
2015-12-01
Near surface geophysical exploration for the purpose of engineering design or construction For this reason, geophysical imaging demands a higher resolution and a better quantitative interpretation. Seismic travel time tomography and direct current resistivity tomography are two main methods for the near surface survey. Because of the limited coverage of observation system and the complex physical relationship between physical parameters and observations, individual geophysical method suffers issues of non-uniqueness and resolution limitation to some degree. We have developed a joint inversion method to combine seismic travel time tomography and full channel resistivity tomography. For the full channel resistivity survey, it uses two electrodes for power supply and all the other electrodes for recording. Compared with the traditional resistivity method, it collects more data and has a better model converge. Our joint inversion strategy relies on the structure constraint enforced through minimizing cross gradients between seismic velocity and resistivity models (Gallardo, 2003). For resistivity tomography, sensitivity kernels are obtained through the adjoint method by solving the electrostatic field equation with the finite-difference method. For seismic travel time tomography, ray paths and travel times are calculated using the fast marching method. We have tested our joint inversion method for a 2D cross-hole problem where two small zones with high and low velocity/resistivity anomalies. Seismic/electrical sources/receivers are installed in two boreholes. For separate seismic inversion, the smearing effect is evident and two anomaly zones are distorted and misplaced. For separate electric resistivity inversion, although two anomaly zones are positioned correctly their values are not accurate. By joint inversion, two velocity anomaly zones are clearly imaged and the smearing effect is greatly reduced. In comparison, for the resistivity model, the two anomaly zones
del Fernández-Alonso, María Carmen; Cañada, Javier; Jiménez-Barbero, Jesús; Cuevas, Gabriel
2005-04-01
Although the potential energy surface of highly symmetric cyclohexane has been extensively reviewed, no attention has been paid to the study of the effect of substitution of a methylene group by a heteroatom. The substitution may cause changes in molecular symmetry as well as the dipole moment, and the unshared electron pairs associated with the heteroatom may also introduce changes in molecular reactivity. However, these phenomena are not yet completely understood. To address these issues, a rigorous description of the inversion-topomerization process of methylcyclohexane and a revision of the conformational potential energy of oxane and thiane are presented. Moreover, the usefulness of providing a three-dimensional representation of these processes is discussed. In the case of methylcyclohexane, calculations show that three transition states are associated with inversion and four more with topomerization. In contrast, for oxane and thiane, only two transition states are involved with inversion and two with topomerization. Two fundamental conclusions can be drawn from this study. The first is that the inversion process occurs through elementary, stages that we have denoted "conformational elemental stages", which is an analogous term to that used for reaction mechanism description (minima-transition state-minima) where several elemental steps take place. The second conclusion is that two independent processes, inversion and topomerization, are connected by some common conformers. The inversion process controls the ring interchange, while topomerization allows exchange between skewed boats.
Design optimization of axial flow hydraulic turbine runner: Part I - an improved Q3D inverse method
NASA Astrophysics Data System (ADS)
Peng, Guoyi; Cao, Shuliang; Ishizuka, Masaru; Hayama, Shinji
2002-06-01
With the aim of constructing a comprehensive design optimization procedure of axial flow hydraulic turbine, an improved quasi-three-dimensional inverse method has been proposed from the viewpoint of system and a set of rotational flow governing equations as well as a blade geometry design equation has been derived. The computation domain is firstly taken from the inlet of guide vane to the far outlet of runner blade in the inverse method and flows in different regions are solved simultaneously. So the influence of wicket gate parameters on the runner blade design can be considered and the difficulty to define the flow condition at the runner blade inlet is surmounted. As a pre-computation of initial blade design on S2m surface is newly adopted, the iteration of S1 and S2m surfaces has been reduced greatly and the convergence of inverse computation has been improved. The present model has been applied to the inverse computation of a Kaplan turbine runner. Experimental results and the direct flow analysis have proved the validation of inverse computation. Numerical investigations show that a proper enlargement of guide vane distribution diameter is advantageous to improve the performance of axial hydraulic turbine runner. Copyright
NASA Astrophysics Data System (ADS)
Kelbert, A.; Schultz, A.; Egbert, G.
2006-12-01
We address the non-linear ill-posed inverse problem of reconstructing the global three-dimensional distribution of electrical conductivity in Earth's mantle. The authors have developed a numerical regularized least-squares inverse solution based on the non-linear conjugate gradients approach. We apply this methodology to the most current low-frequency global observatory data set by Fujii &Schultz (2002), that includes c- and d-responses. We obtain 4-8 layer models satisfying the data. We then describe the features common to all these models and discuss the resolution of our method.
NASA Astrophysics Data System (ADS)
Nguyen, Nhu; Nguyen, Thi
2013-04-01
The Moho depth, crustal thickness and fault systems of the East Vietnam Sea (EVS) are determined by 3D interpretation of satellite gravity. The Moho depth is calculated by 3D Parker inversion from residual gravity anomaly that is obtained by removing the gravity effects of seafloor and Pre-Cenozoic sediment basement topographies from the free air anomaly. The 3D inversion solution is constrained by power density spectrum of gravity anomaly and seismic data. The calculated Moho depths in the EVS vary from 30-31 km near the coast to 9 km in the Central Basin. A map of the lithosphere extension factor in the Cenozoic is constructed from Moho and Pre-Cenozoic sediment basement depths. The fault systems constructed by the maximum horizontal gradient approach include NE-SW, NW-SE, and N-S oriented faults. Based on the interpretation results, the EVS is sub-divided into five structural zones which demonstrated the different characteristics of the crustal structure.
NASA Astrophysics Data System (ADS)
Sosa, Anibal; Thompson, Lennox; Velasco, Aaron A.; Romero, Rodrigo; Herrmann, Robert B.
2014-09-01
The Southern terminus of the Rio Grande Rift region has been poorly defined in the geologic record, with few seismic studies that provide information on the deeper Rift structure. In consequence, important questions related to tectonic and lithospheric activity of the Rio Grande Rift remain unresolved. To address some of these geological questions, we collect and analyze seismic data from 147 EarthScope Transportable Array (USArray) and other seismic stations in the region, to develop a 3-D crust and upper mantle velocity model. We apply a constrained optimization approach for joint inversion of surface wave and receiver functions using seismic S wave velocities as a model parameter. In particular, we compute receiver functions stacks based on ray parameter, and invert them jointly with collected surface wave group velocity dispersion observations. The inversions estimate 1-D seismic S-wave velocity profiles to 300 km depth, which are then interpolated to a 3-D velocity model using a Bayesian kriging scheme. Our 3-D models show a thin lower velocity crust anomaly along the southeastern Rio Grande Rift, a persistent low velocity anomaly underneath the Colorado Plateau and Basin and Range province, and another one at depth beneath the Jemez lineament, and the southern RGR.
NASA Astrophysics Data System (ADS)
Zhang, Ying-Ying; Liu, De-Jun; Ai, Qing-Hui; Qin, Min-Jun
2014-10-01
Electrical resistivity tomography using a steel cased borehole as a long electrode is an advanced technique for geoelectrical survey based on the conventional mise-à-la-masse measurement. In most previous works, the steel casing is simplified as a transmission line current source with an infinitely small radius and constant current density. However, in practical stratified formations with different resistivity values, the current density along the casing cannot be constant. In this study, the steel casing is modeled by a conductive physical volume that the casing occupies in the finite element mesh. The current supply point is set on the center of the top surface of the physical volume. Synthetic modeling, using both a homogenous and layered formation, demonstrates reasonability of the forward modeling method proposed herein. Based on this forward modeling method, the inversion procedure can be implemented by using a freeware R3t (Lancaster University, UK). Inversion results of synthetic modeling data match fairly well with the defined target location and validate that the method works on the inversion of the casing-surface electrical resistivity data. Finally, a field example of Changqing oil field in China is carried out using the inversion method to image water flooding results and to discover wells with great potential to enhance residual oil recovery.
NASA Astrophysics Data System (ADS)
Ballard, S.; Begnaud, M. L.; Hipp, J. R.; Chael, E. P.; Encarnacao, A.; Maceira, M.; Yang, X.; Young, C. J.; Phillips, W.
2013-12-01
SALSA3D is a global 3D P wave velocity model of the Earth's crust and mantle developed specifically to provide seismic event locations that are more accurate and more precise than are locations from 1D and 2.5D models. In this paper, we present the most recent version of our model, for the first time jointly derived from multiple types of data: body wave travel times, surface wave group velocities, and gravity. The latter two are added to provide information in areas with poor body wave coverage, and are down-weighted in areas where body wave coverage is good. To constrain the inversions, we invoked empirical relations among the density, S velocity, and P velocity. We demonstrate the ability of the new SALSA3D model to reduce mislocations and generate statistically robust uncertainty estimates for a large set of realizations derived from a carefully chosen set of globally-distributed ground truth events. We obtain path-dependent travel time prediction uncertainties for our model by computing the full 3D model covariance matrix of our tomographic system and integrating the model slowness variance and covariance along paths of interest. This approach yields very low travel time prediction uncertainties for well-sampled paths through the Earth and higher uncertainties for paths that are poorly represented in the data set used to develop the model. While the calculation of path-dependent prediction uncertainties with this approach is computationally expensive, uncertainties can be pre-computed for a network of stations and stored in 3D lookup tables that can be quickly and efficiently interrogated using GeoTess software.
NASA Astrophysics Data System (ADS)
Martin, Roland; Monteiller, Vadim; Chevrot, Sébastien; Wang, Yi; Komatitsch, Dimitri; Dufréchou, Grégory
2015-04-01
We describe here a method of inversion applied to seismic data sets constrained by gravity data at the regional scale. This will allow us to obtain robust models of P and S wave velocities but also of density, providing key constraints on the composition and thermal state of the lithosphere. Our approach relies on teleseimic waves, which illuminate the medium from below. We have developped a hybrid method in which a wave propagation method at the global scale (DSM/Direct solution method) is coupled with a spectral element method at the regional scale (Monteiller et al. 2013). With the spectral element method, we are able to model the 3D wave propagation effects in a computational domain of 400km long x 400km wide and 200 km deep, for an incident teleseismic wavefront introduced at the boundaries of this domain with periods as short as 2 s. The DSM global method allows to compute this incident field for a spherical Earth model. We use a multi-scale joint inversion of both gravity and seismic waveform data, accounting for the long wavelengths of the gravity field taken from a global model. In terms of inversion technique, we have validated an adjoint method for the inversion of seismic waveforms. An optimized BFGS inversion technique is used to minimize the difference between observed and computed full waveforms. The gradient of the misfit function gives the direction over which the model must be perturbed to minimize this difference. At each step of the inversion procedure we choose an optimal step length that accelerates the minimization. This is the crucial ingredient that allows us to build an efficient iterative full waveform inversion. We have extended this method by incorporating gravity data provided by the BGI/Bureau Gravimétrique International into the inversion. If the waveforms allow us to constrain the seismic velocities, they are less sensitive to the structure in density, which gives independent and crucial information to constrain the nature of rocks
Speidel, M; Hatt, C; Tomkowiak, M; Raval, A; Funk, T
2014-06-15
Purpose: To develop a method for the fusion of 3D echocardiography and Scanning-Beam Digital X-ray (SBDX) fluoroscopy to assist with catheter device and soft tissue visualization during interventional procedures. Methods: SBDX is a technology for low-dose inverse geometry x-ray fluoroscopy that performs digital tomosynthesis at multiple planes in real time. In this study, transesophageal echocardiography (TEE) images were fused with SBDX images by estimating the 3D position and orientation (the “pose”) of the TEE probe within the x-ray coordinate system and then spatially transforming the TEE image data to match this pose. An initial pose estimate was obtained through tomosynthesis-based 3D localization of points along the probe perimeter. Position and angle estimates were then iteratively refined by comparing simulated projections of a 3D probe model against SBDX x-ray images. Algorithm performance was quantified by imaging a TEE probe in different known orientations and locations within the x-ray field (0-30 degree tilt angle, up to 50 mm translation). Fused 3D TEE/SBDX imaging was demonstrated by imaging a tissue-mimicking polyvinyl alcohol cylindrical cavity as a catheter was navigated along the cavity axis. Results: Detected changes in probe tilt angle agreed with the known changes to within 1.2 degrees. For a 50 mm translation along the source-detector axis, the detected translation was 50.3 mm. Errors for in-plane translations ranged from 0.1 to 0.9 mm. In a fused 3D TEE/SBDX display, the catheter device was well visualized and coincident with the device shadow in the TEE images. The TEE images portrayed phantom boundaries that were not evident under x-ray. Conclusion: Registration of soft tissue anatomy derived from TEE imaging and device imaging from SBDX x-ray fluoroscopy is feasible. The simultaneous 3D visualization of these two modalities may be useful in interventional procedures involving the navigation of devices to soft tissue anatomy.
3D Lithospheric Imaging by Time-Domain Full-Waveform Inversion of Teleseismic Body-Waves
NASA Astrophysics Data System (ADS)
Beller, S.; Monteiller, V.; Operto, S.; Nolet, G.; Combe, L.; Metivier, L.; Virieux, J.; Nissen-Meyer, T.; Paul, A.
2014-12-01
With the deployment of dense seismic arrays and the continuous growth of computing facilities, full-waveform inversion (FWI) of teleseismic data has become a method of choice for high-resolution lithospheric imaging. FWI can be recast as a local optimization problem that seeks to estimate Earth's elastic properties by iteratively minimizing the misfit function between observed and modeled seismograms.In passive teleseismic configurations, the seismic source no longer corresponds to a point source embedded in the targeted medium but rather corresponds to a wavefront incoming from the outside of the model. We develop a 3-dimensional time-domain full-waveform inversion program that is more designed for this configuration. The gradient of the misfit function is efficiently computed with the adjoint-state method. A velocity-stress finite-difference time-domain modeling engine, which is interfaced with the so-called total-field/scattered-field method, is used to propagate in the targeted medium the incident wavefield inferred from a global Earth simulation (AxiSEM). Such interfacing is required to account for the multiple arrivals in the incoming wavefield and the sphericity of the Earth. Despite the limited number of nearly plane-wave sources, the interaction of the incident wavefield with the topography (P-Sv conversions and P-P reflections acting as secondary sources) provides a suitable framework to record both transmitted wavefields and reflected wavefields from lithospheric reflectors. These recordings of both transmitted and reflected waves makes FWI amenable to a broadband-wavenumber (i.e., high resolution) reconstruction of the lithosphere.Feasibility of the method is assessed with a realistic synthetic model representative of the Western Alps. One key issue is the estimation of the temporal source excitation, as there might be some trade-off between the source estimation and the subsurface update. To avoid being trapped in a local minimum, we follow a
NASA Astrophysics Data System (ADS)
Voznyuk, I.; Litman, A.; Tortel, H.
2015-08-01
A Quasi-Newton method for reconstructing the constitutive parameters of three-dimensional (3D) penetrable scatterers from scattered field measurements is presented. This method is adapted for handling large-scale electromagnetic problems while keeping the memory requirement and the time flexibility as low as possible. The forward scattering problem is solved by applying the finite-element tearing and interconnecting full-dual-primal (FETI-FDP2) method which shares the same spirit as the domain decomposition methods for finite element methods. The idea is to split the computational domain into smaller non-overlapping sub-domains in order to simultaneously solve local sub-problems. Various strategies are proposed in order to efficiently couple the inversion algorithm with the FETI-FDP2 method: a separation into permanent and non-permanent subdomains is performed, iterative solvers are favorized for resolving the interface problem and a marching-on-in-anything initial guess selection further accelerates the process. The computational burden is also reduced by applying the adjoint state vector methodology. Finally, the inversion algorithm is confronted to measurements extracted from the 3D Fresnel database.
NASA Astrophysics Data System (ADS)
Uzkeda, Hodei; Bulnes, Mayte; Poblet, Josep; García-Ramos, José Carlos; Piñuela, Laura
2016-09-01
We constructed a geological map, a 3D model and cross-sections, carried out a structural analysis, determined the stress fields and tectonic transport vectors, restored a cross section and performed a subsidence analysis to unravel the kinematic evolution of the NE emerged portion of the Asturian Basin (NW Iberian Peninsula), where Jurassic rocks crop out. The major folds run NW-SE, normal faults exhibit three dominant orientations: NW-SE, NE-SW and E-W, and thrusts display E-W strikes. After Upper Triassic-Lower Jurassic thermal subsidence, Middle Jurassic doming occurred, accompanied by normal faulting, high heat flow and basin uplift, followed by Upper Jurassic high-rate basin subsidence. Another extensional event, possibly during Late Jurassic-Early Cretaceous, caused an increment in the normal faults displacement. A contractional event, probably of Cenozoic age, led to selective and irregularly distributed buttressing and fault reactivation as reverse or strike-slip faults, and folding and/or offset of some previous faults by new generation folds and thrusts. The Middle Jurassic event could be a precursor of the Bay of Biscay and North Atlantic opening that occurred from Late Jurassic to Early Cretaceous, whereas the Cenozoic event would be responsible for the Pyrenean and Cantabrian ranges and the partial closure of the Bay of Biscay.
Camargo-Junior, Franklin; Ackermann, Marko; Loss, Jefferson F; Sacco, Isabel C N
2013-12-01
The aim of this study was to investigate the effect of errors in the location of the center of pressure (5 and 10 mm) on lower limb joint moment uncertainties at different gait velocities (1.0, 1.5, and 2.0 m/s). Our hypotheses were that the absolute joint moment uncertainties would be gradually reduced from distal to proximal joints and from higher to lower velocities. Joint moments of five healthy young adults were calculated by inverse dynamics using the bottom-up approach, depending on which estimate the uncertainty propagated. Results indicated that there is a linear relationship between errors in center of pressure and joint moment uncertainties. The absolute moment peak uncertainties expressed on the anatomic reference frames decreased from distal to proximal joints, confirming our first hypothesis, except for the abduction moments. There was an increase in moment uncertainty (up to 0.04 N m/kg for the 10 mm error in the center of pressure) from the lower to higher gait velocity, confirming our second hypothesis, although, once again, not for hip or knee abduction. Finally, depending on the plane of movement and the joint, relative uncertainties experienced variation (between 5 and 31%), and the knee joint moments were the most affected.
NASA Astrophysics Data System (ADS)
Ross, Z.; Ben-Zion, Y.; Zhu, L.; Graves, R. W.
2015-12-01
We perform a full source tensor inversion of several M > 4 earthquakes that occurred in the San Jacinto fault zone in southern California, with an emphasis on resolving signatures of volumetric source changes. A previous study on these events with Green's functions based on a 1D velocity model identified statistically significant explosive isotropic components (Ross et al. 2015). Here we use the SCEC 3D Community Velocity Model to derive Green's functions with source-receiver reciprocity and finite-difference calculations based on the code of Graves (1996). About 50 stations are used at epicentral distances of up to 55 km. The inversions are performed using the 'generalized Cut and Paste' method, which includes CLVD and isotropic components (Zhu and Ben-Zion 2013). The derived source tensors are compared to the results of the previous study based on the simplified 1D velocity model. The results are analyzed with bootstrap analysis to estimate uncertainties involved. Additional tests are performed using synthetic waveforms to study the effects of neglecting various features on the source inversions.
NASA Astrophysics Data System (ADS)
Ercoli, Maurizio; Pauselli, Cristina; Frigeri, Alessandro; Forte, Emanuele; Federico, Costanzo
2014-07-01
The activation of Late Quaternary faults in the Central Apennines (Italy) could generate earthquakes with magnitude of about 6.5, and the Monte Vettore fault system probably belongs to the same category of seismogenetic faults. Such structure has been defined `silent', because of its geological and geomorphological evidences of past activation, but the absence of historical records in the seismic catalogues to be associated with its activation. The `Piano di Castelluccio' intramountain basin, resulting from the Quaternary activity of normal faults, is characterized by a secondary fault strand highlighted by a NW-SE fault scarp: it has been already studied through palaeoseismological trenches, which highlighted evidences of Quaternary shallow faulting due to strong earthquakes, and through a 2-D ground penetrating radar (GPR) survey, showing the first geophysical signature of faulting for this site. Within the same place, a 3-D GPR volume over a 20 × 20 m area has been collected. The collection of radar echoes in three dimensions allows to map both the vertical and lateral continuity of shallow geometries of the fault zone (Fz), imaging features with high resolution, ranging from few metres to centimetres and therefore imaging also local variations at the microscale. Several geophysical markers of faulting, already highlighted on this site, have been taken as reference to plan the 3-D survey. In this paper, we provide the first 3-D subsurface imaging of an active shallow fault belonging to the Umbria-Marche Apennine highlighting the subsurface fault geometry and the stratigraphic sequence up to a depth of about 5 m. From our data, geophysical faulting signatures are clearly visible in three dimensions: diffraction hyperbolas, truncations of layers, local attenuated zones and varying dip of the layers have been detected within the Fz. The interpretation of the 3-D data set provided qualitative and quantitative geological information in addition to the fault location
Oldenburg, Amy L.; Yu, Xiao; Gilliss, Thomas; Alabi, Oluwafemi; Taylor, Russell M.; Troester, Melissa A.
2015-01-01
The progression of breast cancer is known to be affected by stromal cells within the local microenvironment. Here we study the effect of stromal fibroblasts on the in-place motions (motility) of mammary epithelial cells within organoids in 3D co-culture, inferred from the speckle fluctuation spectrum using optical coherence tomography (OCT). In contrast to Brownian motion, mammary cell motions exhibit an inverse power-law fluctuation spectrum. We introduce two complementary metrics for quantifying fluctuation spectra: the power-law exponent and a novel definition of the motility amplitude, both of which are signal- and position-independent. We find that the power-law exponent and motility amplitude are positively (p<0.001) and negatively (p<0.01) correlated with the density of stromal cells in 3D co-culture, respectively. We also show how the hyperspectral data can be visualized using these metrics to observe heterogeneity within organoids. This constitutes a simple and powerful tool for detecting and imaging cellular functional changes with OCT. PMID:26973862
Wang, Aijun; Liu, Wenfang; Tang, Junjie; Chen, Sheng-Li; Dong, Peng
2014-04-15
A photonic bandgap (PBG) extension of surface-disordered 3D photonic crystals (PCs) based on the TiO2 inverse opal (TiO2-IO) architecture has been demonstrated. By using a liquid phase deposition (LPD) process based on the controlled hydrolysis of ammonium hexafluorotitanate and boric acid, an extra layer of TiO2 nanoparticles were deposited onto the internal surface of the air voids in the TiO2-IOs to increase their surface roughness, thereby introducing surface disorder in the 3D order structures. The PBG relative width of surface-disordered TiO2-IOs has been broadened significantly, and, compared to the original TiO2-IO, its largest rate of increase (27%) has been obtained. It was found that the PBG relative width increased rapidly at first and then to a much slower rate of change with increase of the duration of the LPD time. A possible cause for this finding is discussed in this Letter. PMID:24978999
NASA Astrophysics Data System (ADS)
Mashayekhi, Parisa; Ghorbani-Dashtaki, Shoja; Mosaddeghi, Mohammad Reza; Shirani, Hossein; Nodoushan, Ali Reza Mohammadi
2016-04-01
In this study, HYDRUS-2D/3D was used to simulate ponded infiltration through double-ring infiltrometers into a hypothetical loamy soil profile. Twelve scenarios of inverse modelling (divided into three groups) were considered for estimation of Mualem-van Genuchten hydraulic parameters. In the first group, simulation was carried out solely using cumulative infiltration data. In the second group, cumulative infiltration data plus water content at h = -330 cm (field capacity) were used as inputs. In the third group, cumulative infiltration data plus water contents at h = -330 cm (field capacity) and h = -15 000 cm (permanent wilting point) were used simultaneously as predictors. The results showed that numerical inverse modelling of the double-ring infiltrometer data provided a reliable alternative method for determining soil hydraulic parameters. The results also indicated that by reducing the number of hydraulic parameters involved in the optimization process, the simulation error is reduced. The best one in infiltration simulation which parameters α, n, and Ks were optimized using the infiltration data and field capacity as inputs. Including field capacity as additional data was important for better optimization/definition of soil hydraulic functions, but using field capacity and permanent wilting point simultaneously as additional data increased the simulation error.
NASA Astrophysics Data System (ADS)
von Hebel, Christian; Rudolph, Sebastian; Huisman, Johan A.; van der Kruk, Jan; Vereecken, Harry
2013-04-01
three different coil offsets in HCP and VCP measurement modes. This resulted in six high spatial resolution data sets of approximately 60000 measurements with different sensing depths. A 5 m block-kriging was applied to all six data sets to re-grid the sampling points on the same regular grid. For each grid node, the six measured apparent conductivities were used in a three-layer inversion. The three-layer inversion results of electrical conductivity thus obtained were used to derive a three-dimensional (3D) model of subsurface heterogeneity, which clearly indicated lateral and vertical conductivity changes of the subsurface that are related to changes in soil texture and soil water content.
NASA Astrophysics Data System (ADS)
Liang, Q.; Chen, C.; Kaban, M. K.; Thomas, M.
2014-12-01
Mantle density structure is a key for tectonics. The density variations in the upper mantle are affected by temperature and composition. Seismic tomography method has been widely applied to obtain the P- and S-wave velocity structure in the mantle, which is then used to calculate the density perturbation. However, the velocity model is mainly due to the thermal effects but not the compositional effects. A method of 3-D inversion of gravity anomaly developed in spherical coordinates is used to image the large-scale density structure of upper mantle in Southeast Asia. The mantle gravity anomalies used in inversion are calculated by removing the crustal effects from the observed gravity. With constraints of thermal density model from seismic tomography, the integrative density structure is estimated from gravity inversion. Consequently, we obtain the compositional density by subtracting the thermal density from the integrative structure. The result of inversion shows the anisotropic composition of subduction zones, Cratons and plates boundary in Southeast Asia. In the shallow depth, the compositional density anomalies of large scales present uniform features in oceanic and continental mantle. In depth of 75-175 km, there are differences between the thermal and the compositional variations. The density anomalies at these depths are both affected by temperature and composition of the upper mantle. Below 175-km depth, the density anomalies are dominated by the compositional variations. Furthermore, comparing with high seismicity occurred at moderate-depth (50-300 km), we found that the compositional density variations is one of the factor that inducing earthquakes. The constrained inversion of mantle gravity anomaly has possibility to reveal the subduction which is not clearly seen from low-resolution tomography data, and may reveal the relation of seismicity and composition in the upper mantle. This study is supported by the Program of International Science and
NASA Astrophysics Data System (ADS)
Afonso, J. C.; Fullea, J.; Yang, Y.; Connolly, J. A. D.; Jones, A. G.
2013-04-01
Here we present a 3-D multi-observable probabilistic inversion method, particularly designed for high-resolution (regional) thermal and compositional mapping of the lithosphere and sub-lithospheric upper mantle that circumvents the problems associated with traditional inversion methods. The key aspects of the method are as follows: (a) it exploits the increasing amount and quality of geophysical datasets; (b) it combines multiple geophysical observables (Rayleigh and Love dispersion curves, body-wave tomography, magnetotelluric, geothermal, petrological, gravity, elevation, and geoid) with different sensitivities to deep/shallow, thermal/compositional anomalies into a single thermodynamic-geophysical framework; (c) it uses a general probabilistic (Bayesian) formulation to appraise the data; (d) no initial model is needed; (e) compositional a priori information relies on robust statistical analyses of a large database of natural mantle samples; and (f) it provides a natural platform to estimate realistic uncertainties. In addition, the modular nature of the method/algorithm allows for incorporating or isolating specific forward operators according to available data. The strengths and limitations of the method are thoroughly explored with synthetic models. It is shown that the a posteriori probability density function (i.e., solution to the inverse problem) satisfactorily captures spatial variations in bulk composition and temperature with high resolution, as well as sharp discontinuities in these fields. Our results indicate that only temperature anomalies of ΔT ⪆150°C and large compositional anomalies of ΔMg# > 3 (or bulk ΔAl2O3 > 1.5) can be expected to be resolved simultaneously when combining high-quality geophysical data. This resolving power is sufficient to explore some long-standing problems regarding the nature and evolution of the lithosphere (e.g., vertical stratification of cratonic mantle, compositional versus temperature signatures in seismic
West Flank Coso FORGE Magnetotelluric 3D Data
Doug Blankenship
2016-01-01
This is the 3D version of the MT data for the West Flank FORGE area.The Coso geothermal field has had three Magnetotelluric (MT) datasets collected including surveys in 2003, 2006, and 2011. The final collection, in 2011, expanded the survey to the west and covers the West Flank of FORGE area.This most recent data set was collected by Schlumberger/WesternGeco and inverted by the WesternGeco GeoSolutions Integrated EM Center of Excellence in Milan, Italy; the 2003 and 2006 data were integrated for these inversions in the present study.
NASA Astrophysics Data System (ADS)
Afonso, J. C.; Fullea, J.; Griffin, W. L.; Yang, Y.; Jones, A. G.; D. Connolly, J. A.; O'Reilly, S. Y.
2013-05-01
of natural mantle samples collected from different tectonic settings (xenoliths, abyssal peridotites, ophiolite samples, etc.). This strategy relaxes more typical and restrictive assumptions such as the use of local/limited xenolith data or compositional regionalizations based on age-composition relations. We demonstrate that the combination of our ρ(m) with a L(m) that exploits the differential sensitivities of specific geophysical observables provides a general and robust inference platform to address the thermochemical structure of the lithosphere and sublithospheric upper mantle. An accompanying paper deals with the integration of these two functions into a general 3-D multiobservable Bayesian inversion method and its computational implementation.
NASA Technical Reports Server (NTRS)
Pazmany, Andrew L.; Reehorst, Andrew (Technical Monitor)
2001-01-01
The Mount Washington Icing Sensors Project (MWISP) was a multi-investigator experiment with participants from Quadrant Engineering, NOAA Environmental Technology Laboratory (NOAA/ETL), the Microwave Remote Sensing Laboratory (MIRSL) of the University of Massachusetts (UMass), and others. Radar systems from UMass and NOAA/ETL were used to measure X-, Ka-, and W-band backscatter data from the base of Mt. Washington, while simultaneous in-situ particle measurements were made from aircraft and from the observatory at the summit. This report presents range and time profiles of liquid water content and particle size parameters derived from range profiles of radar reflectivity as measured at X-, Ka-, and W-band (9.3, 33.1, and 94.9 GHz) using an artificial neural network inversion algorithm. In this report, we provide a brief description of the experiment configuration, radar systems, and a review of the artificial neural network used to extract cloud parameters from the radar data. Time histories of liquid water content (LWC), mean volume diameter (MVD) and mean Z diameter (MZD) are plotted at 300 m range intervals for slant ranges between 1.1 and 4 km. Appendix A provides details on the extraction of radar reflectivity from measured radar power, and Appendix B provides summary logs of the weather conditions for each day in which we processed data.
NASA Astrophysics Data System (ADS)
Luciani, S.; LeNiliot, C.
2008-11-01
Two-phase and boiling flow instabilities are complex, due to phase change and the existence of several interfaces. To fully understand the high heat transfer potential of boiling flows in microscale's geometry, it is vital to quantify these transfers. To perform this task, an experimental device has been designed to observe flow patterns. Analysis is made up by using an inverse method which allows us to estimate the local heat transfers while boiling occurs inside a microchannel. In our configuration, the direct measurement would impair the accuracy of the searched heat transfer coefficient because thermocouples implanted on the surface minichannels would disturb the established flow. In this communication, we are solving a 3D IHCP which consists in estimating using experimental data measurements the surface temperature and the surface heat flux in a minichannel during convective boiling under several gravity levels (g, 1g, 1.8g). The considered IHCP is formulated as a mathematical optimization problem and solved using the boundary element method (BEM).
NASA Astrophysics Data System (ADS)
Suzuki, W.; Aoi, S.; Maeda, T.; Sekiguchi, H.; Kunugi, T.
2013-12-01
Source inversion analysis using near-source strong-motion records with an assumption of 1-D underground structure models has revealed the overall characteristics of the rupture process of the 2011 Tohoku-Oki mega-thrust earthquake. This assumption for the structure model is acceptable because the seismic waves radiated during the Tohoku-Oki event were rich in the very-low-frequency contents lower than 0.05 Hz, which are less affected by the small-scale heterogeneous structure. The analysis using more reliable Green's functions even in the higher-frequency range considering complex structure of the subduction zone will illuminate more detailed rupture process in space and time and the transition of the frequency dependence of the wave radiation for the Tohoku-Oki earthquake. In this study, we calculate the near-source Green's functions using a 3-D underground structure model and perform the source inversion analysis using them. The 3-D underground structure model used in this study is the Japan Integrated Velocity Structure Model (Headquarters for Earthquake Research Promotion, 2012). A curved fault model on the Pacific plate interface is discretized into 287 subfaults at ~20 km interval. The Green's functions are calculated using GMS (Aoi et al., 2004), which is a simulation program package for the seismic wave field by the finite difference method using discontinuous grids (Aoi and Fujiwara, 1999). Computational region is 136-146.2E in longitude, 34-41.6N in latitude, and 0-100 km in depth. The horizontal and vertical grid intervals are 200 m and 100 m, respectively, for the shallower region and those for the deeper region are tripled. The number of the total grids is 2.1 billion. We derive 300-s records by calculating 36,000 steps with a time interval of 0.0083 second (120 Hz sampling). It takes nearly one hour to compute one case using 48 Graphics Processing Units (GPU) on TSUBAME2.0 supercomputer owned by Tokyo Institute of Technology. In total, 574 cases are
NASA Astrophysics Data System (ADS)
Macquet, Marie; Paul, Anne; Pedersen, Helle A.; Villaseñor, Antonio; Chevrot, Sébastien; Sylvander, Matthieu; Wolyniec, David; Pyrope Working Group
2014-10-01
The lithospheric architecture of the Pyrenees is still uncertain and highly debated. Here, we provide new constraints from a high-resolution 3-D S-wave velocity model of the Pyrenees and the adjacent foreland basins. This model is obtained from ambient noise tomography on records of temporary and permanent seismic arrays installed in southwestern France and northern Spain. We first computed group velocity maps for Rayleigh waves in the 5 to 55 s period range using noise correlation stacks at 1500-8500 station pairs. As the crust is very heterogeneous, poor results were obtained using a single starting model in a linearized inversion of group velocity dispersion curves for the shear wave structure. We therefore built a starting model for each grid node by full exploration of the model space. The resulting 3-D shear wave velocity model is compared to data from previous geophysical studies as a validation test. Despite the poor sensitivity of surface waves to seismic discontinuities, the geometry of the top of the basement and the Moho depth are retrieved well, except along the Cantabrian coast. Major reflectors of the ECORS deep seismic sounding profiles in the central and western Pyrenees coincide with sharp velocity gradients in our velocity model. We retrieve the difference between the thicker Iberian crust and the thinner European crust, the presence of low-velocity material of the Iberian crust underthrust beneath the European crust in the central Pyrenees, and the structural dissymmetry between the South Pyrenean Zone and the North Pyrenean Zone at the shallow crustal level. In the Labourd-Mauléon-Arzacq region (western Pyrenees), there is a high S-wave velocity anomaly at 20-30 km in depth, which might explain the positive Bouguer anomaly of the Labourd Massif. This high-velocity lower crust, which is also detected beneath the Parentis area, might be an imprint of the Albian-Aptian rifting phase. The southeastern part of the Massif Central has an unusual
NASA Astrophysics Data System (ADS)
Favier, L.; Zwinger, T.; Gillet-Chaulet, F.; Durand, G.; Gagliardini, O.
2012-04-01
Ice discharge and grounding line retreat in West Antarctica have been accelerated during the last decades. One of the most striking example is Pine Island Glacier (PIG) which accelerated dramatically over the last 30 years. Such rapid changes in this part of Antarctica are due to large modifications of ice dynamics which are nevertheless poorly understood, and badly represented in numerical models, as pointed out by the IPCC fourth assessment report. Here, a 3D full-Stokes model of a marine ice sheet is used to carry out prognostic simulations of PIG over the next two centuries. The flow problem is coupled with the evolution of the upper and lower free surfaces, and the position of the grounding line is determined by solving the contact problem between the ice-shelf/ice-sheet lower surface and the bedrock. The upper and lower surfaces, and the bathymetry provided on a 1 km grid (courtesy of A. Le Brocq) are used to produce the initial geometry of the entire PIG basin. The mesh refinement is a function of the surface velocities (also provided on a 1 km grid by A. Le Brocq) Hessian matrix and the distance to the grounding line. Surface velocities are also used to infer the basal drag through the resolution of an inverse Robin problem. The initial surface is first relaxed and the results are compared to the observed current surface elevation, surface velocity and change in surface elevation. A perturbation experiment is then performed for which the whole ice-shelf is instantaneously removed. This test can be seen as a worst case scenario as all the buttressing induced by the ice shelf is lost instantaneously. The effect of the ice-shelf disintegration for the following two centuries is discussed in terms of grounding line retreat and increase in sea level.
NASA Astrophysics Data System (ADS)
Tietze, Kristina; Ritter, Oliver
2013-10-01
3-D inversion techniques have become a widely used tool in magnetotelluric (MT) data interpretation. However, with real data sets, many of the controlling factors for the outcome of 3-D inversion are little explored, such as alignment of the coordinate system, handling and influence of data errors and model regularization. Here we present 3-D inversion results of 169 MT sites from the central San Andreas Fault in California. Previous extensive 2-D inversion and 3-D forward modelling of the data set revealed significant along-strike variation of the electrical conductivity structure. 3-D inversion can recover these features but only if the inversion parameters are tuned in accordance with the particularities of the data set. Based on synthetic 3-D data we explore the model space and test the impacts of a wide range of inversion settings. The tests showed that the recovery of a pronounced regional 2-D structure in inversion of the complete impedance tensor depends on the coordinate system. As interdependencies between data components are not considered in standard 3-D MT inversion codes, 2-D subsurface structures can vanish if data are not aligned with the regional strike direction. A priori models and data weighting, that is, how strongly individual components of the impedance tensor and/or vertical magnetic field transfer functions dominate the solution, are crucial controls for the outcome of 3-D inversion. If deviations from a prior model are heavily penalized, regularization is prone to result in erroneous and misleading 3-D inversion models, particularly in the presence of strong conductivity contrasts. A `good' overall rms misfit is often meaningless or misleading as a huge range of 3-D inversion results exist, all with similarly `acceptable' misfits but producing significantly differing images of the conductivity structures. Reliable and meaningful 3-D inversion models can only be recovered if data misfit is assessed systematically in the frequency
ERIC Educational Resources Information Center
Brown, Malcolm
2009-01-01
Inversions are fascinating phenomena. They are reversals of the normal or expected order. They occur across a wide variety of contexts. What do inversions have to do with learning spaces? The author suggests that they are a useful metaphor for the process that is unfolding in higher education with respect to education. On the basis of…
NASA Astrophysics Data System (ADS)
Marinin, I. V.; Kabanikhin, S. I.; Krivorotko, O. I.; Karas, A.; Khidasheli, D. G.
2012-04-01
We consider new techniques and methods for earthquake and tsunami related problems, particularly - inverse problems for the determination of tsunami source parameters, numerical simulation of long wave propagation in soil and water and tsunami risk estimations. In addition, we will touch upon the issue of database management and destruction scenario visualization. New approaches and strategies, as well as mathematical tools and software are to be shown. The long joint investigations by researchers of the Institute of Mathematical Geophysics and Computational Mathematics SB RAS and specialists from WAPMERR and Informap have produced special theoretical approaches, numerical methods, and software tsunami and earthquake modeling (modeling of propagation and run-up of tsunami waves on coastal areas), visualization, risk estimation of tsunami, and earthquakes. Algorithms are developed for the operational definition of the origin and forms of the tsunami source. The system TSS numerically simulates the source of tsunami and/or earthquakes and includes the possibility to solve the direct and the inverse problem. It becomes possible to involve advanced mathematical results to improve models and to increase the resolution of inverse problems. Via TSS one can construct maps of risks, the online scenario of disasters, estimation of potential damage to buildings and roads. One of the main tools for the numerical modeling is the finite volume method (FVM), which allows us to achieve stability with respect to possible input errors, as well as to achieve optimum computing speed. Our approach to the inverse problem of tsunami and earthquake determination is based on recent theoretical results concerning the Dirichlet problem for the wave equation. This problem is intrinsically ill-posed. We use the optimization approach to solve this problem and SVD-analysis to estimate the degree of ill-posedness and to find the quasi-solution. The software system we developed is intended to
NASA Astrophysics Data System (ADS)
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.
Walroth, Richard C; Lukens, James T; MacMillan, Samantha N; Finkelstein, Kenneth D; Lancaster, Kyle M
2016-02-17
The contested electronic structure of [Cu(CF3)4](1-) is investigated with UV/visible/near IR spectroscopy, Cu K-edge X-ray absorption spectroscopy, and 1s2p resonant inelastic X-ray scattering. These data, supported by density functional theory, multiplet theory, and multireference calculations, support a ground state electronic configuration in which the lowest unoccupied orbital is of predominantly trifluoromethyl character. The consensus 3d(10) configuration features an inverted ligand field in which all five metal-localized molecular orbitals are located at lower energy relative to the trifluoromethyl-centered σ orbitals.
Yoshida, Ayako; Shiratori, Yoko; Suzuki, Makoto; Ozasa, Masaya; Takeyama, Mamoru; Eshima, Mitsuhiro; Shinohara, Maiko; Yamamoto, Takao; Tajima, Tsuyoshi
2015-05-01
To evaluate whether electrocardiography-gated is useful in non-contrast-enhanced MRA with time-spatial labeling inversion pulse (Time-SLIP) in renal transplantation patients compared with respiration-triggered free-breathing. Simulation-based analyses of black blood time interval (BBTI) values for spatial selective inversion-recovery pulse and electrocardiography rates were performed, and confirmed on human subjects using a three-dimensional (3D) coherent steady-state free precession (SSFP) sequence on a 1.5 tesla Toshiba MRI scanner. Signal acquisition interval and BBTI values in which signal of a water tissue becomes the null point showed a strong correlation, and successfully suppressed signals from the background and provided better contrast between the arteries and the background. Because electrocardiography-gated non-contrast MRA does not depend on the respiration interval, providing a contrast stable, it was suggested to be an effective screening tool for evaluation of pelvic arteries.
NASA Astrophysics Data System (ADS)
Khalil, Mohamed A.; Santos, Fernando M.; Farzamian, Mohammad
2014-04-01
Sinai Peninsula occupies a part of the arid zone belt of northern Africa and southwestern Asia. The largest ephemeral stream in the Sinai Peninsula is called Wadi El-Arish, which winds down northward to the Mediterranean Sea. The delta of Wadi El-Arish has been built by the heavy floods of the Wadi. The Quaternary aquifer is the main water supply of the delta of Wadi El-Arish and its vicinities. The combined action of aridity and extensive pumping from the Quaternary aquifer led to a noticeable increase in groundwater salinity. The hydrochemistry and isotope hydrology confirm that the Quaternary aquifer is recharged by an old saline groundwater from the Pre-Quaternary. A hydrogeological connection between Quaternary and Pre-Quaternary aquifers in the form of fault(s) should exist to explain the hydro-tectonic regime of this area. The Bouguer gravity map shows the high gravity anomaly of the doubly plunging anticline of Risan Aniza Mountain to the south of El-Arish area, which is a part of the Syrian Arc System of northern Sinai Peninsula. A 3D density contrast model, 3D Euler deconvolution, horizontal derivative and least square separation have been performed. The findings showed that (1) two deep regional faults extending NE-SW, surround the Risan Aniza anticline, and (2) two deep local N-S faults are in the area of Delta Wadi El-Arish. These deep faults are proposed to bring the deep Cretaceous aquifer into contact with the shallow Quaternary aquifer and work as a hydrogeological connection between both aquifers. The present hypothesis has some geological evidences from the subsurface lithology of the nearby wells.
NASA Astrophysics Data System (ADS)
Massoud, Usama; Soliman, Mamdouh; Taha, Ayman; Khozym, Ashraf; Salah, Hany
2015-12-01
Seawater intrusion is a widespread environmental problem in the Egyptian coastal aquifers. It affects the groundwater used in domestic and agricultural activities along these coasts. In this study, resistivity survey in the form of Vertical Electrical Sounding (VES) was conducted at ZAWYET EL HAWALA cultivated site, northwest coast of Egypt to outline a freshwater zone overlies the main saltwater body, and to determine the most suitable location for drilling water well for irrigation purposes. The VES data were measured at 11 stations in the studied site. After processing, the data were inverted in 1-D and 3-D schemes and the final model was presented as resistivity slices with depth. The results indicate that the effect of saltwater intrusion was observed, as low resistivity values, at 7.5 m below ground surface (bgs) at the northern part of the study area (toward the Mediterranean Sea), and extends southward with increasing depth covering the whole area at about 30 m bgs. The fresh water zone shows a minimum thickness of less than 7.5 m at the northern side and a maximum thickness of about 20 m at the southern side of the area. The proper site for drilling water well tap and the freshwater zone is the location of VES6 or VES9 with a maximum well depth of about 20 m bgs. The water withdrawal from the proposed well should be controlled not to raise the main saline water table in the well site. The main sources of the freshwater zone are the rainfall and surface runoff descending from the southern tableland. Excess rainfall and surface runoff can be avoided from direct discharge to the sea by collecting them in man-made outlined trenches and re-using the stored water in irrigation during the dry seasons.
Lee, Sunbok; Lee, Youngshin; Kim, Dong Ha; Moon, Jun Hyuk
2013-12-11
We for the first time demonstrated carbon-deposited TiO2 inverse opal (C-TiO2 IO) structures as highly efficient visible photocatalysts. The carbon deposition proceeded via high-temperature pyrolysis of phloroglucinol/formaldehyde resol, which had been coated onto the TiO2 IO structures. Carbon deposition formed a carbon layer and doped the TiO2 interface, which synergistically enhanced visible-light absorption. We directly measured the visible-light photocatalytic activity by constructing solar cells comprising the C-TiO2 IO electrode. Photocatalytic degradation of organic dyes in a solution was also evaluated. Photocatalytic dye degradation under visible light was only observed in the presence of the C-TiO2 IO sample and was increased with the content of carbon deposition. The IO structures could be readily decorated with TiO2 nanoparticles to increase the surface area and enhance the photocatalytic activity. Notably, the photocatalytic reaction was found to proceed in a viscous polymeric solution. A comparison of the mesoporous TiO2 structure and the IO TiO2 structure revealed that the latter performed better as the solution viscosity increased. This result was attributed to facile diffusion into the fully connected and low-tortuosity macropore network of the IO structure. PMID:24266769
NASA Astrophysics Data System (ADS)
Käufl, Paul; Valentine, Andrew P.; Trampert, Jeannot
2016-08-01
Despite the ever increasing availability of computational power, real-time source inversions based on physical modeling of wave propagation in realistic media remain challenging. We investigate how a nonlinear Bayesian approach based on pattern recognition and synthetic 3-D Green's functions can be used to rapidly invert strong-motion data for point source parameters by means of a case study for a fault system in the Los Angeles Basin. The probabilistic inverse mapping is represented in compact form by a neural network which yields probability distributions over source parameters. It can therefore be evaluated rapidly and with very moderate CPU and memory requirements. We present a simulated real-time inversion of data for the 2008 Mw 5.4 Chino Hills event. Initial estimates of epicentral location and magnitude are available ˜14 s after origin time. The estimate can be refined as more data arrive: by ˜40 s, fault strike and source depth can also be determined with relatively high certainty.
NASA Astrophysics Data System (ADS)
Efstathiou, Angeliki; Tzanis, Andreas; Chailas, Stylianos; Stamatakis, Michael
2013-04-01
We report the results of a joint analysis of geophysical (aeromagnetic) and seismotectonic data, applied to the investigation of the deep structure, magmatic activity and geothermal potential of the north-western stretches of the Hellenic Volcanic Arc (HVA). The HVA is usually considered to be a single arcuate entity stretching from Sousaki (near Corinth) at the NW, to Nisyros Island at the SE. However, different types of and their ages indicate the presence of two different volcanic groups. Our study focuses on the northern part of the west (older) volcanic group and includes the Crommyonian (Sousaki) volcanic field at the west end of Megaris peninsula (east margin on the contemporary Corinth Rift), the Aegina and Methana volcanic complex at the Saronic Gulf, where typical Quaternary calc-alkaline volcanics predominate, and the Argolid peninsula to the south and south-west. In addition to the rocks associated with Quaternary volcanism, the study area includes a series of Mesozoic ultramafic (ophiolitic) outcrops at the Megaris peninsula, to the north and north-east of the Crommyonian volcanic field, as well as throughout the Argolid. A major deep structural and tectonic feature of the study area, and one with profound influence on crustal deformation and the evolution of rapidly deforming extensional structures like the Corinth Rift and the Saronic Gulf, is the local geometry and dynamics of the African oceanic crust subducting beneath the Aegean plate. Locally, the subducting slab has a NNW strike and ENE plunge, with the dip angle changing rapidly (steepening) approx. beneath the Argolid. The aeromagnetic data was extracted from the recently (re)compiled aeromagnetic map of Greece (Chailas et al, 2010) and was inverted with the UBC-GIF magnetic inversion suite (Li and Oldenburg, 1996). The inversion included rigorous geological constraints introduced by means of numerous in-situ magnetic susceptibility measurements. The inversion has imaged several isolated
NASA Astrophysics Data System (ADS)
Lee, Tae Jong; Nam, Myung Jin; Lee, Seong Kon; Song, Yoonho; Uchida, Toshihiro
2009-06-01
Magnetotelluric (MT) surveys have been performed along five lines in the Jeju volcanic island located at South Sea of Korea. The purposes of the MT surveys are to see if there still remains thermal regime and if there exist deeply extended fractures or an aquifer system beneath the mid-mountain region of Mt. Halla in Jeju. By performing Audio-frequency MT (AMT) surveys together with MT surveys at each site and by operating far-remote reference site of approximately 480 km apart, we could get a broadband (10 - 4 -10 4 Hz) MT dataset of totally 108 sites with very good quality. 3D inversion of MT data from 88 measurement sites gives a reasonable estimation of the subsurface structures beneath the island. An induction vector analysis and 3D inversion results commonly indicate the existence of a conductive anomaly extended down to a few-kilometer depth beneath the central part of the island, which can be related to ancient volcanic activities. Because the island is surrounded by electrically conductive sea and has steep topographic variation, measured MT data in terms of impedance is seriously biased by distortion of electric fields and is suffered from the static shifts. The Jeju MT dataset is valuable for the research purpose in the sense that the dataset contains so many problems, some of which can frequently be observed in every field data, and that the geology of Jeju Island is relatively simple.
NASA Astrophysics Data System (ADS)
Park, Sunyoung; Ishii, Miaki
2015-11-01
Rupture properties, such as rupture direction, length, propagation speed and source duration, provide important insights into earthquake mechanisms. One approach to estimate these properties is to investigate the body-wave duration that depends upon the relative location of the station with respect to the rupture direction. Under the assumption that the propagation is unilateral, the duration can be expressed as a function of the dip and azimuth of the rupture. Examination of duration measurements with respect to both the take-off angle and the azimuth is crucial to obtain robust estimates of rupture parameters, especially for nearly vertical rupture propagation. Moreover, limited data coverage, such as using only teleseismic data, can bias the source duration estimate for dipping ruptures, and this bias can map into estimates of other source properties such as rupture extent and rupture speed. Based upon this framework, we introduce an inversion scheme that uses the duration measurements to obtain four parameters: the source duration, a measure of the rupture extent and speed, and dip and azimuth of the rupture propagation. The method is applied to two deep-focus events in the Sea of Okhotsk region, an Mw 7.7 event that occurred on 2012 August 14 and an Mw 8.3 event from 2013 May 24. The source durations are 26 ± 1 and 37 ± 1 s, and rupture speeds are 49 ± 4 per cent and 26 ± 3 per cent of shear wave speed for the Mw 7.7 and 8.3 events, respectively. The azimuths of the two ruptures are parallel to the trench, but are in opposite directions. The dips of the Mw 7.7 and 8.3 events are constrained to be 48° ± 8° downdip and 19° ± 8° updip, respectively. The fit to the data is significantly poorer for the Mw 8.3 event than the Mw 7.7 event, suggesting that the unilateral rupture may not be a good assumption. The analysis is expanded into a multi-episode model, and a secondary episode is determined for the Mw 8.3 event in the southeast direction. The two
Doug Blankenship
2011-05-04
This data includes the locations of the MT data collected in and around the Coso Geothermal field that covered the West Flank area. These are the data that the 3D MT models were created from that were discussed in Phase 1 of the West Flank FORGE project. The projected coordinate system is NAD 1927 State Plane California IV FIPS 0404 and the Projection is Lambert Conformal Conic. Units are in feet.
NASA Astrophysics Data System (ADS)
Abbassi, B.; Huebert, J.; Liu, L.; Lee, B.; Cheng, L.; Richards, J. P.; Unsworth, M. J.; Oldenburg, D.
2013-12-01
The Newton property is an epithermal Au-Ag deposit containing precious metals in association with disseminated sulfide minerals such as pyrite. This type of deposit often shows variable geological patterns, so it is important to find fast and cost-efficient methods for their exploration. Aeromagnetic surveys and ground electrical resistivity-induced polarization methods were applied over the Newton property. From preliminary 3D inversion of ZTEM and aeromagnetic data, and joint 3D inversion of electrical resistivity-induced polarization data, we show that low-resistivity and high-chargeability regions are signatures of disseminated sulfide mineralization. Potassic alteration, characterized by hydrothermal biotite (now mostly chloritized) and magnetite is also present locally, and may be related to underlying porphyry-type mineralization. This type of alteration can be identified from its magnetic signature, but the occurrence of other magnetic formations in the deposit area made interpretations of magnetic data difficult. We show that filtering geological noises related to background magnetic anomalies is an essential step in focusing on potassic alteration zones. We used electrical resistivity and induced polarization chargeability models to remove the signals of barren magnetic zones to focus on the susceptibilities pertaining to deep potassic alterations. In order to test the credibility of these interpretations, extensive petrophysical measurements (magnetic susceptibility, electrical resistivity, and gamma ray spectra) were collected on drill-core samples. We show that potassic alteration can also be characterized accurately from high levels of potassium to thorium ratio (K/Th) in gamma ray spectrometric measurements, and that this correlation is stronger than the magnetic signal (likely because hydrothermal magnetite is variable in abundance). Therefore, we focused on magnetic susceptibility values correlated with high K/Th ratios in order to reduce the
NASA Astrophysics Data System (ADS)
Bremner, P. M.; Panning, M. P.; Russo, R. M.; Mocanu, V. I.; Stanciu, A. C.; Torpey, M. E.; Hongsresawat, S.; VanDecar, J. C.
2014-12-01
We present the latest 3-D isotropic crustal velocity model beneath central Idaho and eastern Oregon. We produced the velocity model from vertical component Rayleigh wave group and phase velocity measurements on data from the IDaho/ORegon (IDOR) Passive seismic network, 86 broadband seismic stations, using ambient noise tomography and the methods of Gallego et. al (2010) and Lin et. al (2008). We calculated inter-station group/phase velocities in narrow frequency bands from travel-time measurements of the stacked cross-correlations (bandpass filtered between 2 and 30 seconds), which we used to invert for velocity structure beneath the network. Goals of our work include refining models of crustal structure in the accreted Blue Mountain terranes in the western study area; determining the depth extent of the Salmon River Suture/West Idaho Shear Zone (WISZ), which crosses north-south through the middle of the network; determining the architecture of the Idaho batholith, an extensive largely crustal-derived pluton; and examining the nature of the autochthonous (?) North American crust and lithosphere beneath and east of the batholith. We derived Rayleigh wave group and phase velocity maps for each frequency band using the damped least-squares inversion method of Tarantola (2005), and then jointly inverted for velocity with depth. Moho depths are prescribed in the joint inversions based on receiver functions, also from the IDOR seismic data, and provides a starting crustal velocity model. 3-D checkerboard resolution tests indicate lateral resolution of better than 40 km. Preliminary results show higher S wave velocities in the western study area, and lower velocities in the lower crust on the east side of the network, consistent with Basin-and-Range style extension there. A tabular velocity anomaly juxtaposing higher above lower seismic velocities dips shallow west in the midcrust on the west side of the network.
Clement, T.P.; Jones, N.L.
1998-02-01
RT3D (Reactive Transport in 3-Dimensions) is a computer code that solves coupled partial differential equations that describe reactive-flow and transport of multiple mobile and/or immobile species in a three dimensional saturated porous media. RT3D was developed from the single-species transport code, MT3D (DoD-1.5, 1997 version). As with MT3D, RT3D also uses the USGS groundwater flow model MODFLOW for computing spatial and temporal variations in groundwater head distribution. This report presents a set of tutorial problems that are designed to illustrate how RT3D simulations can be performed within the Department of Defense Groundwater Modeling System (GMS). GMS serves as a pre- and post-processing interface for RT3D. GMS can be used to define all the input files needed by RT3D code, and later the code can be launched from within GMS and run as a separate application. Once the RT3D simulation is completed, the solution can be imported to GMS for graphical post-processing. RT3D v1.0 supports several reaction packages that can be used for simulating different types of reactive contaminants. Each of the tutorials, described below, provides training on a different RT3D reaction package. Each reaction package has different input requirements, and the tutorials are designed to describe these differences. Furthermore, the tutorials illustrate the various options available in GMS for graphical post-processing of RT3D results. Users are strongly encouraged to complete the tutorials before attempting to use RT3D and GMS on a routine basis.
NASA Astrophysics Data System (ADS)
Bremner, P. M.; Panning, M. P.; Russo, R.; Mocanu, V. I.; Stanciu, A. C.; Torpey, M. E.; Hongsresawat, S.; VanDecar, J. C.
2015-12-01
We present new 3-D radially anisotropic and isotropic crustal velocity models beneath central Idaho and eastern Oregon. We produced the velocity models from Love and horizontal component Rayleigh wave group and phase velocity measurements on the IDaho/ORegon (IDOR) Passive seismic network, 86 broadband seismic stations, dataset using ambient noise tomography and the methods of Gallego et. al (2010) and Lin et. al (2008). We calculated inter-station group/phase velocities in narrow frequency bands from travel-time measurements of the rotated stacked horizontal component cross-correlations (bandpass filtered between 2 and 30 seconds), which we used to invert for velocity structure beneath the network. We derived group and phase velocity maps for each frequency band using the damped least-squares inversion method of Tarantola (2005), and then jointly inverted for velocity with depth. Moho depths are prescribed in the joint inversions based on receiver functions, also from the IDOR seismic data, and provides a starting crustal velocity model. Goals of our work include refining models of crustal structure in the accreted Blue Mountain terranes in the western study area; determining the depth extent of the Salmon River Suture/West Idaho Shear Zone (WISZ), which crosses north-south through the middle of the network; determining the architecture of the Idaho batholith, an extensive largely crustal-derived pluton; and examining the nature of the autochthonous (?) North American crust and lithosphere beneath and east of the batholith.
NASA Astrophysics Data System (ADS)
Ren, Cong; Liu, Tong; Maturavongsadit, Panita; Luckanagul, Jittima Amie; Chen, Fanglin
2015-04-01
Anode-supported micro-tubular solid oxide fuel cells (MT-SOFCs) have been fabricated by phase inversion method. For the anode support preparation, N-methyl-2-pyrrolidone (NMP), polyethersulfone (PESf) and poly ethylene glycol (PEG) were applied as solvent, polymer binder and additive, respectively. The effect of molecular weight and amount of PEG additive on the thermodynamics of the casting solutions was characterized by measuring the coagulation value. Viscosity of the casting slurries was also measured and the influence of PEG additive on viscosity was studied and discussed. The presence of PEG in the casting slurry can significantly influence the final anode support microstructure. Based on the microstructure result and the measured gas permeation value, two anode supports were selected for cell fabrication. For cell with the anode support fabricated using slurry with PEG additive, a maximum cell power density of 704 mW cm-2 is obtained at 750 °C with humidified hydrogen as fuel and ambient air as oxidant; cell fabricated without any PEG additive shows the peak cell power density of 331 mW cm-2. The relationship between anode microstructure and cell performance was discussed.
NASA Astrophysics Data System (ADS)
Pletinckx, D.
2011-09-01
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.
3d-3d correspondence revisited
NASA Astrophysics Data System (ADS)
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.
3d-3d correspondence revisited
Chung, Hee -Joong; Dimofte, Tudor; Gukov, Sergei; Sułkowski, Piotr
2016-04-21
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. As a result, we also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.
NASA Astrophysics Data System (ADS)
Ronchin, Erika; Masterlark, Timothy; Dawson, John; Saunders, Steve; Martí Molist, Joan
2015-04-01
In this study, we present a method to fully integrate a family of finite element models (FEMs) into the regularized linear inversion of InSAR data collected at Rabaul caldera (PNG) between February 2007 and December 2010. During this period the caldera experienced a long-term steady subsidence that characterized surface movement both inside the caldera and outside, on its western side. The inversion is based on an array of FEM sources in the sense that the Green's function matrix is a library of forward numerical displacement solutions generated by the sources of an array common to all FEMs. Each entry of the library is the LOS surface displacement generated by injecting a unity mass of fluid, of known density and bulk modulus, into a different source cavity of the array for each FEM. By using FEMs, we are taking advantage of their capability of including topography and heterogeneous distribution of elastic material properties. All FEMs of the family share the same mesh in which only one source is activated at the time by removing the corresponding elements and applying the unity fluid flux. The domain therefore only needs to be discretized once. This precludes remeshing for each activated source, thus reducing computational requirements, often a downside of FEM-based inversions. Without imposing an a-priori source, the method allows us to identify, from a least-squares standpoint, a complex distribution of fluid flux (or change in pressure) with a 3D free geometry within the source array, as dictated by the data. The results of applying the proposed inversion to Rabaul InSAR data show a shallow magmatic system under the caldera made of two interconnected lobes located at the two opposite sides of the caldera. These lobes could be consistent with feeding reservoirs of the ongoing Tavuvur volcano eruption of andesitic products, on the eastern side, and of the past Vulcan volcano eruptions of more evolved materials, on the western side. The interconnection and
NASA Astrophysics Data System (ADS)
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?
3D Magnetotelluic characterization of the Coso GeothermalField
Newman, Gregory A.; Hoversten, G. Michael; Wannamaker, Philip E.; Gasperikova, Erika
2007-04-23
-dimensional conductivitymodel. Initial analysis of the Coso MT data was carried out using 2D MTimaging. An initial 3D conductivity model was constructed from a seriesof 2D resistivity images obtained using the inline electric fieldmeasurements (Zyx impedance elements) along several measurementtransects. This model was then refined through a 3D inversion process.This model shows the controlling geological structures possiblyinfluencing well production at Coso and correlations with mapped surfacefeatures such as faults and regional geoelectric strike. The 3D modelalso illustrates the refinement in positioning of conductivity contactswhen compared to isolated 2D inversion transects. The conductivity modelhas also been correlated with microearthquake locations, well fluidproduction intervals and most importantly with an acoustic and shearvelocity model derived by Wu and Lees (1999). This later correlationshows the near-vertical high conductivity structure on the eastern flankof the producing field is also a zone of increased acoustic velocity andincreased Vp/Vs ratio bounded by mapped fault traces. South of theDevil's Kitchen is an area of high geothermal well density, where highlyconductive near surface material is interpreted as a clay cap alterationzone manifested from the subsurface geothermal fluids and relatedgeochemistry. Beneath the clay cap, however, the conductivity isnondescript, whereas the Vp/Vs ratio is enhanced over the productionintervals. It is recommended that more MT data sites be acquired to thesouthwest of the Devil's Kitchen area to better refine the conductivitymodel in that area.
The role of MT2-MMP in cancer progression
Ito, Emiko; Yana, Ikuo; Fujita, Chisato; Irifune, Aiko; Takeda, Maki; Madachi, Ayako; Mori, Seiji; Hamada, Yoshinosuke; Kawaguchi, Naomasa; Matsuura, Nariaki
2010-03-05
The role of MT2-MMP in cancer progression remains to be elucidated in spite of many reports on MT1-MMP. Using a human fibrosarcoma cell, HT1080 and a human gastric cancer cell, TMK-1, endogenous expression of MT1-MMP or MT2-MMP was suppressed by siRNA induction to examine the influence of cancer progression in vitro and in vivo. In HT1080 cells, positive both in MT1-MMP and MT2-MMP, the migration as well as the invasion was impaired by MT1-MMP or MT2-MMP suppression. Also cell proliferation in three dimensional (3D) condition was inhibited by MT1-MMP or MT2-MMP suppression and tumor growth in the nude mice transplanted with tumor cells were reduced either MT1-MMP or MT2-MMP suppression with a prolongation of survival time in vivo. MT2-MMP suppression induces more inhibitory effects on 3D proliferation and in vivo tumor growth than MT1-MMP. On the other hand, TMK-1 cells, negative in MT1-MMP and MMP-2 but positive in MT2-MMP, all the migratory, invasive, and 3D proliferative activities in TMK-1 are decreased only by MT2-MMP suppression. These results indicate MT2-MMP might be involved in the cancer progression more than or equal to MT1-MMP independently of MMP-2 and MT1-MMP.
ERIC Educational Resources Information Center
Hastings, S. K.
2002-01-01
Discusses 3 D imaging as it relates to digital representations in virtual library collections. Highlights include X-ray computed tomography (X-ray CT); the National Science Foundation (NSF) Digital Library Initiatives; output peripherals; image retrieval systems, including metadata; and applications of 3 D imaging for libraries and museums. (LRW)
Semiautomatic and Automatic Cooperative Inversion of Seismic and Magnetotelluric Data
NASA Astrophysics Data System (ADS)
Le, Cuong V. A.; Harris, Brett D.; Pethick, Andrew M.; Takam Takougang, Eric M.; Howe, Brendan
2016-09-01
Natural source electromagnetic methods have the potential to recover rock property distributions from the surface to great depths. Unfortunately, results in complex 3D geo-electrical settings can be disappointing, especially where significant near-surface conductivity variations exist. In such settings, unconstrained inversion of magnetotelluric data is inexorably non-unique. We believe that: (1) correctly introduced information from seismic reflection can substantially improve MT inversion, (2) a cooperative inversion approach can be automated, and (3) massively parallel computing can make such a process viable. Nine inversion strategies including baseline unconstrained inversion and new automated/semiautomated cooperative inversion approaches are applied to industry-scale co-located 3D seismic and magnetotelluric data sets. These data sets were acquired in one of the Carlin gold deposit districts in north-central Nevada, USA. In our approach, seismic information feeds directly into the creation of sets of prior conductivity model and covariance coefficient distributions. We demonstrate how statistical analysis of the distribution of selected seismic attributes can be used to automatically extract subvolumes that form the framework for prior model 3D conductivity distribution. Our cooperative inversion strategies result in detailed subsurface conductivity distributions that are consistent with seismic, electrical logs and geochemical analysis of cores. Such 3D conductivity distributions would be expected to provide clues to 3D velocity structures that could feed back into full seismic inversion for an iterative practical and truly cooperative inversion process. We anticipate that, with the aid of parallel computing, cooperative inversion of seismic and magnetotelluric data can be fully automated, and we hold confidence that significant and practical advances in this direction have been accomplished.
NASA Astrophysics Data System (ADS)
Samrock, F.; Kuvshinov, A.; Bakker, J.; Jackson, A.; Fisseha, S.
2015-09-01
The Main Ethiopian Rift Valley encompasses a number of volcanoes, which are known to be actively deforming with reoccurring periods of uplift and setting. One of the regions where temporal changes take place is the Aluto volcanic complex. It hosts a productive geothermal field and the only currently operating geothermal power plant of Ethiopia. We carried out magnetotelluric (MT) measurements in early 2012 in order to identify the source of unrest. Broad-band MT data (0.001-1000 s) have been acquired at 46 sites covering the expanse of the Aluto volcanic complex with an average site spacing of 1 km. Based on this MT data it is possible to map the bulk electrical resistivity of the subsurface down to depths of several kilometres. Resistivity is a crucial geophysical parameter in geothermal exploration as hydrothermal and magmatic reservoirs are typically related to low resistive zones, which can be easily sensed by MT. Thus by mapping the electrical conductivity one can identify and analyse geothermal systems with respect to their temperature, extent and potential for production of energy. 3-D inversions of the observed MT data from Aluto reveal the typical electrical conductivity distribution of a high-enthalpy geothermal system, which is mainly governed by the hydrothermal alteration mineralogy. The recovered 3-D conductivity models provide no evidence for an active deep magmatic system under Aluto. Forward modelling of the tippers rather suggest that occurrence of melt is predominantly at lower crustal depths along an off-axis fault zone a few tens of kilometres west of the central rift axis. The absence of an active magmatic system implies that the deforming source is most likely situated within the shallow hydrothermal system of the Aluto-Langano geothermal field.
3D conductivity image of a young continental rift: Taupo Volcanic Zone, New Zealand
NASA Astrophysics Data System (ADS)
Heise, W.; Caldwell, T. G.; Bibby, H. M.; Bennie, S. L.
2009-04-01
The Taupo Volcanic Zone (TVZ), in the North Island, New Zealand is a continental back arc rift associated with the subduction of the Pacific Plate under the Australian Plate and is characterised by the eruption of large volumes of rhyolitic magma during the last 1.6 Ma and an exceptionally high present-day heat flow. Data from 220 magnetotelluric soundings covering the central (rhyolitic) part of the TVZ were analysed using 3D inverse resistivity modelling and phase tensor visualisation techniques. Modelling results compare well with the thickness of conductive volcaniclastic material in filling the rift basin and calderas and expected from observed gravity anomalies. Phase tensor ellipticity correlates well with the resistivity gradient in the 3D inversion model showing how the phase data control the inversion and allowing identification of which structures are, or are not, resolved by the data. The inverse modelling results show a zone of high conductivity in the lower crust and upper-mantle along the central rift-axis that correlates with a zone of high phase observed at long periods. An unusual feature of the MT data at periods of 3-30s is the large phase tensor skew angle values that coincide with the margins of a localized gravity high in the centre of the survey area. This feature appears to be caused by the interaction of a thick near surface layer of high conductive volcaniclastic material with conductive structures at greater depth.
NASA Astrophysics Data System (ADS)
Meqbel, Naser; Weckmann, Ute; Muñoz, Gerard; Ritter, Oliver
2016-09-01
We report on a study to explore the deep electrical conductivity structure of the Dead Sea Basin (DSB) using magnetotelluric (MT) data collected along a transect across the DSB where the left lateral strike slip Dead Sea transform fault (DST) splits into two fault strands forming one of the largest pull-apart basins of the world. A very pronounced feature of our 2D inversion model is a deep, sub-vertical conductive zone beneath the DSB. The conductor extends through the entire crust and is sandwiched between highly resistive structures associated with Precambrian rocks of the basin flanks. The high electrical conductivity could be attributed to fluids released by dehydration of the uppermost mantle beneath the DSB, possibly in combination with fluids released by mid to low grade metamorphism in the lower crust and generation of hydrous minerals in the middle crust through retrograde metamorphism. Similar high conductivity zones associated with fluids have been reported from other large fault systems. The presence of fluids and hydrous minerals in the middle and lower crust could explain the required low friction coefficient of the DST along the eastern boundary of the Dead Sea basin and the high subsidence rate of basin sediments. 3D inversion models confirm the existence of a sub-vertical high conductivity structure underneath the DSB but its expression is far less pronounced. Instead, the 3D inversion model suggests a deepening of the conductive DSB sediments off-profile towards the south, reaching a maximum depth of approximately 12 km, which is consistent with other geophysical observations. At shallower levels, the 3D inversion model reveals salt diapirism as an upwelling of highly resistive structures, localized underneath the Al-Lisan Peninsula. The 3D model furthermore contains an E-W elongated conductive structure to the north-east of the Dead Sea basin. More MT data with better spatial coverage are required, however, to fully constrain the robustness of
NASA Astrophysics Data System (ADS)
Oldham, Mark
2015-01-01
Radiochromic materials exhibit a colour change when exposed to ionising radiation. Radiochromic film has been used for clinical dosimetry for many years and increasingly so recently, as films of higher sensitivities have become available. The two principle advantages of radiochromic dosimetry include greater tissue equivalence (radiologically) and the lack of requirement for development of the colour change. In a radiochromic material, the colour change arises direct from ionising interactions affecting dye molecules, without requiring any latent chemical, optical or thermal development, with important implications for increased accuracy and convenience. It is only relatively recently however, that 3D radiochromic dosimetry has become possible. In this article we review recent developments and the current state-of-the-art of 3D radiochromic dosimetry, and the potential for a more comprehensive solution for the verification of complex radiation therapy treatments, and 3D dose measurement in general.
NASA Astrophysics Data System (ADS)
Moore, Gregory F.
2009-05-01
This volume is a brief introduction aimed at those who wish to gain a basic and relatively quick understanding of the interpretation of three-dimensional (3-D) seismic reflection data. The book is well written, clearly illustrated, and easy to follow. Enough elementary mathematics are presented for a basic understanding of seismic methods, but more complex mathematical derivations are avoided. References are listed for readers interested in more advanced explanations. After a brief introduction, the book logically begins with a succinct chapter on modern 3-D seismic data acquisition and processing. Standard 3-D acquisition methods are presented, and an appendix expands on more recent acquisition techniques, such as multiple-azimuth and wide-azimuth acquisition. Although this chapter covers the basics of standard time processing quite well, there is only a single sentence about prestack depth imaging, and anisotropic processing is not mentioned at all, even though both techniques are now becoming standard.
Iliesiu, Luca; Kos, Filip; Poland, David; Pufu, Silviu S.; Simmons-Duffin, David; Yacoby, Ran
2016-03-17
We study the conformal bootstrap for a 4-point function of fermions <ψψψψ> in 3D. We first introduce an embedding formalism for 3D spinors and compute the conformal blocks appearing in fermion 4-point functions. Using these results, we find general bounds on the dimensions of operators appearing in the ψ × ψ OPE, and also on the central charge CT. We observe features in our bounds that coincide with scaling dimensions in the GrossNeveu models at large N. Finally, we also speculate that other features could coincide with a fermionic CFT containing no relevant scalar operators.
NASA Astrophysics Data System (ADS)
Plaut, J. J.
1993-08-01
Stereographic images of the surface of Venus which enable geologists to reconstruct the details of the planet's evolution are discussed. The 120-meter resolution of these 3D images make it possible to construct digital topographic maps from which precise measurements can be made of the heights, depths, slopes, and volumes of geologic structures.
Van, B.T.; Pajon, J.L.; Joseph, P. )
1991-11-01
This paper shows how some simple 3D computer graphics tools can be combined to provide efficient software for visualizing and analyzing data obtained from reservoir simulators and geological simulations. The animation and interactive capabilities of the software quickly provide a deep understanding of the fluid-flow behavior and an accurate idea of the internal architecture of a reservoir.
3D Elastic Wavefield Tomography
NASA Astrophysics Data System (ADS)
Guasch, L.; Warner, M.; Stekl, I.; Umpleby, A.; Shah, N.
2010-12-01
Wavefield tomography, or waveform inversion, aims to extract the maximum information from seismic data by matching trace by trace the response of the solid earth to seismic waves using numerical modelling tools. Its first formulation dates from the early 80's, when Albert Tarantola developed a solid theoretical basis that is still used today with little change. Due to computational limitations, the application of the method to 3D problems has been unaffordable until a few years ago, and then only under the acoustic approximation. Although acoustic wavefield tomography is widely used, a complete solution of the seismic inversion problem requires that we account properly for the physics of wave propagation, and so must include elastic effects. We have developed a 3D tomographic wavefield inversion code that incorporates the full elastic wave equation. The bottle neck of the different implementations is the forward modelling algorithm that generates the synthetic data to be compared with the field seismograms as well as the backpropagation of the residuals needed to form the direction update of the model parameters. Furthermore, one or two extra modelling runs are needed in order to calculate the step-length. Our approach uses a FD scheme explicit time-stepping by finite differences that are 4th order in space and 2nd order in time, which is a 3D version of the one developed by Jean Virieux in 1986. We chose the time domain because an explicit time scheme is much less demanding in terms of memory than its frequency domain analogue, although the discussion of wich domain is more efficient still remains open. We calculate the parameter gradients for Vp and Vs by correlating the normal and shear stress wavefields respectively. A straightforward application would lead to the storage of the wavefield at all grid points at each time-step. We tackled this problem using two different approaches. The first one makes better use of resources for small models of dimension equal
NASA Astrophysics Data System (ADS)
Agata, R.; Ichimura, T.; Hori, T.; Hirahara, K.; Hori, M.
2012-12-01
Crustal deformation analysis is important in order to understand the interplate coupling and coseismic fault slips. To perform it more accurately, we need a high-fidelity crustal structure model. However, in spite of accumulated crustal data, models with simplified flat shapes or relatively low resolution have been used, because the computation cost using high-fidelity models with a large degree-of-freedom (DOF) could be significantly high. Especially, estimation of the interplate coupling and coseismic fault slip requires the calculation of Green's function (the response displacement due to unit fault slip). To execute this computation in a realistic time, we need to reduce the computation cost. The objectives of our research is following: (1)To develop a method to generate 3D Finite Element (FE) models which represent heterogeneous crustal layers with the complex shape of crustal structure; (2)To develop a fast FE analysis method to perform crustal deformation analysis many times using single computation node, supposing the use of a small-scale computation environment. We developed an automatic FE model generation method using background grids with high quality meshes in a large area by extending the method of (Ichimura et al, 2009). We used Finite Element Method (FEM) because it has an advantage in representing the shape. Hybrid meshes consisting of tetrahedral and voxel elements are generated; the former is used when the interface surfaces and the grids intersect so that the shape of the crust is represented well, while the latter is used in the homogeneous areas. Also, we developed a method for crustal deformation analysis due to fault slip, which solves the FEM equation Ku=f assuming that the crust is an elastic body. To compute it fast, firstly we solved the problem by CG method with a simple preconditioning, parallelizing it by OpenMP. However, this computation took a long time, so we improved the method by introducing Multigrid Method (Saam, 2003) to the
RAG-3D: A search tool for RNA 3D substructures
Zahran, Mai; Sevim Bayrak, Cigdem; Elmetwaly, Shereef; Schlick, Tamar
2015-08-24
In this study, 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 describedmore » 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.« less
RAG-3D: A search tool for RNA 3D substructures
Zahran, Mai; Sevim Bayrak, Cigdem; Elmetwaly, Shereef; Schlick, Tamar
2015-08-24
In this study, 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.
RAG-3D: a search tool for RNA 3D substructures
Zahran, Mai; Sevim Bayrak, Cigdem; Elmetwaly, Shereef; Schlick, Tamar
2015-01-01
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
NASA Astrophysics Data System (ADS)
Isaksson, Folke; Borg, Johan; Haglund, Leif
2008-04-01
In this paper the performance of passive range measurement imaging using stereo technique in real time applications is described. Stereo vision uses multiple images to get depth resolution in a similar way as Synthetic Aperture Radar (SAR) uses multiple measurements to obtain better spatial resolution. This technique has been used in photogrammetry for a long time but it will be shown that it is now possible to do the calculations, with carefully designed image processing algorithms, in e.g. a PC in real time. In order to get high resolution and quantitative data in the stereo estimation a mathematical camera model is used. The parameters to the camera model are settled in a calibration rig or in the case of a moving camera the scene itself can be used for calibration of most of the parameters. After calibration an ordinary TV camera has an angular resolution like a theodolite, but to a much lower price. The paper will present results from high resolution 3D imagery from air to ground. The 3D-results from stereo calculation of image pairs are stitched together into a large database to form a 3D-model of the area covered.
Shim3d Helmholtz Solution Package
2009-01-29
This suite of codes solves the Helmholtz Equation for the steady-state propagation of single-frequency electromagnetic radiation in an arbitrary 2D or 3D dielectric medium. Materials can be either transparent or absorptive (including metals) and are described entirely by their shape and complex dielectric constant. Dielectric boundaries are assumed to always fall on grid boundaries and the material within a single grid cell is considered to be uniform. Input to the problem is in the formmore » of a Dirichlet boundary condition on a single boundary, and may be either analytic (Gaussian) in shape, or a mode shape computed using a separate code (such as the included eigenmode solver vwave20), and written to a file. Solution is via the finite difference method using Jacobi iteration for 3D problems or direct matrix inversion for 2D problems. Note that 3D problems that include metals will require different iteration parameters than described in the above reference. For structures with curved boundaries not easily modeled on a rectangular grid, the auxillary codes helmholtz11(2D), helm3d (semivectoral), and helmv3d (full vectoral) are provided. For these codes the finite difference equations are specified on a topological regular triangular grid and solved using Jacobi iteration or direct matrix inversion as before. An automatic grid generator is supplied.« less
Taming supersymmetric defects in 3d-3d correspondence
NASA Astrophysics Data System (ADS)
Gang, Dongmin; Kim, Nakwoo; Romo, Mauricio; Yamazaki, Masahito
2016-07-01
We study knots in 3d Chern-Simons theory with complex gauge group {SL}(N,{{C}}), in the context of its relation with 3d { 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,{{C}}) CS theory, in 3d { N }=2 theory, in 5d { 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 [1], which contains more details and more results.
NASA Technical Reports Server (NTRS)
1992-01-01
Ames Research Center research into virtual reality led to the development of the Convolvotron, a high speed digital audio processing system that delivers three-dimensional sound over headphones. It consists of a two-card set designed for use with a personal computer. The Convolvotron's primary application is presentation of 3D audio signals over headphones. Four independent sound sources are filtered with large time-varying filters that compensate for motion. The perceived location of the sound remains constant. Possible applications are in air traffic control towers or airplane cockpits, hearing and perception research and virtual reality development.
Zaiss, Moritz; Xu, Junzhong; Goerke, Steffen; Khan, Imad S; Singer, Robert J; Gore, John C; Gochberg, Daniel F; Bachert, Peter
2014-03-01
Endogenous chemical exchange saturation transfer (CEST) effects are always diluted by competing effects, such as direct water proton saturation (spillover) and semi-solid macromolecular magnetization transfer (MT). This leads to unwanted T2 and MT signal contributions that lessen the CEST signal specificity to the underlying biochemical exchange processes. A spillover correction is of special interest for clinical static field strengths and protons resonating near the water peak. This is the case for all endogenous CEST agents, such as amide proton transfer, -OH-CEST of glycosaminoglycans, glucose or myo-inositol, and amine exchange of creatine or glutamate. All CEST effects also appear to be scaled by the T1 relaxation time of water, as they are mediated by the water pool. This forms the motivation for simple metrics that correct the CEST signal. Based on eigenspace theory, we propose a novel magnetization transfer ratio (MTRRex ), employing the inverse Z-spectrum, which eliminates spillover and semi-solid MT effects. This metric can be simply related to Rex , the exchange-dependent relaxation rate in the rotating frame, and ka , the inherent exchange rate. Furthermore, it can be scaled by the duty cycle, allowing for simple translation to clinical protocols. For verification, the amine proton exchange of creatine in solutions with different agar concentrations was studied experimentally at a clinical field strength of 3 T, where spillover effects are large. We demonstrate that spillover can be properly corrected and that quantitative evaluation of pH and creatine concentration is possible. This proves that MTRRex is a quantitative and biophysically specific CEST-MRI metric. Applied to acute stroke induced in rat brain, the corrected CEST signal shows significantly higher contrast between the stroke area and normal tissue, as well as less B1 dependence, than conventional approaches.
Constructing 3D microtubule networks using holographic optical trapping
Bergman, J.; Osunbayo, O.; Vershinin, M.
2015-01-01
Developing abilities to assemble nanoscale structures is a major scientific and engineering challenge. We report a technique which allows precise positioning and manipulation of individual rigid filaments, enabling construction of custom-designed 3D filament networks. This approach uses holographic optical trapping (HOT) for nano-positioning and microtubules (MTs) as network building blocks. MTs are desirable engineering components due to their high aspect ratio, rigidity, and their ability to serve as substrate for directed nano-transport, reflecting their roles in the eukaryotic cytoskeleton. The 3D architecture of MT cytoskeleton is a significant component of its function, however experimental tools to study the roles of this geometric complexity in a controlled environment have been lacking. We demonstrate the broad capabilities of our system by building a self-supporting 3D MT-based nanostructure and by conducting a MT-based transport experiment on a dynamically adjustable 3D MT intersection. Our methodology not only will advance studies of cytoskeletal networks (and associated processes such as MT-based transport) but will also likely find use in engineering nanostructures and devices. PMID:26657337
3D differential phase contrast microscopy
NASA Astrophysics Data System (ADS)
Chen, Michael; Tian, Lei; Waller, Laura
2016-03-01
We demonstrate three-dimensional (3D) optical phase and amplitude reconstruction based on coded source illumination using a programmable LED array. Multiple stacks of images along the optical axis are computed from recorded intensities captured by multiple images under off-axis illumination. Based on the first Born approximation, a linear differential phase contrast (DPC) model is built between 3D complex index of refraction and the intensity stacks. Therefore, 3D volume reconstruction can be achieved via a fast inversion method, without the intermediate 2D phase retrieval step. Our system employs spatially partially coherent illumination, so the transverse resolution achieves twice the NA of coherent systems, while axial resolution is also improved 2× as compared to holographic imaging.
NASA Technical Reports Server (NTRS)
1997-01-01
Many prominent rocks near the Sagan Memorial Station are featured in this image, taken in stereo by the Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses are necessary to identify surface detail. Wedge is at lower left; Shark, Half-Dome, and Pumpkin are at center. Flat Top, about four inches high, is at lower right. The horizon in the distance is one to two kilometers away.
Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.
Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right
NASA Technical Reports Server (NTRS)
2004-01-01
This 3-D, microscopic imager mosaic of a target area on a rock called 'Diamond Jenness' was taken after NASA's Mars Exploration Rover Opportunity ground into the surface with its rock abrasion tool for a second time.
Opportunity has bored nearly a dozen holes into the inner walls of 'Endurance Crater.' On sols 177 and 178 (July 23 and July 24, 2004), the rover worked double-duty on Diamond Jenness. Surface debris and the bumpy shape of the rock resulted in a shallow and irregular hole, only about 2 millimeters (0.08 inch) deep. The final depth was not enough to remove all the bumps and leave a neat hole with a smooth floor. This extremely shallow depression was then examined by the rover's alpha particle X-ray spectrometer.
On Sol 178, Opportunity's 'robotic rodent' dined on Diamond Jenness once again, grinding almost an additional 5 millimeters (about 0.2 inch). The rover then applied its Moessbauer spectrometer to the deepened hole. This double dose of Diamond Jenness enabled the science team to examine the rock at varying layers. Results from those grindings are currently being analyzed.
The image mosaic is about 6 centimeters (2.4 inches) across.
NASA Technical Reports Server (NTRS)
1997-01-01
This area of terrain near the Sagan Memorial Station was taken on Sol 3 by the Imager for Mars Pathfinder (IMP). 3D glasses are necessary to identify surface detail.
The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.
Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.
Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right
West Flank Coso, CA FORGE Magnetotelluric Inversion
Doug Blankenship
2016-05-16
The Coso Magnetotelluric (MT) dataset of which the West Flank FORGE MT data is a subset, was collected by Schlumberger / WesternGeco and initially processed by the WesternGeco GeoSolutions Integrated EM Center of Excellence in Milan, Italy. The 2011 data was based on 99 soundings that were centered on the West Flank geothermal prospect. The new soundings along with previous data from 2003 and 2006 were incorporated into a 3D inversion. Full impedance tensor data were inverted in the 1-3000 Hz range. The modelling report notes several noise sources, specifically the DC powerline that is 20,000 feet west of the survey area, and may have affected data in the 0.02 to 10 Hz range. Model cell dimensions of 450 x 450 x 65 feet were used to avoid computational instability in the 3D model. The fit between calculated and observed MT values for the final model run had an RMS value of 1.807. The included figure from the WesternGeco report shows the sounding locations from the 2011, 2006 and 2003 surveys.
Carlos Torres-Verdin; Mrinal K. Sen
2004-03-01
The present report summarizes the work carried out between September 30, 2002 and August 30, 2003 under DOE research contract No. DE-FC26-00BC15305. During the third year of work for this project we focused primarily on improving the efficiency of inversion algorithms and on developing algorithms for direct estimation of petrophysical parameters. The full waveform inversion algorithm for elastic property estimation was tested rigorously on a personal computer cluster. For sixteen nodes on the cluster the parallel algorithm was found to be scalable with a near linear speedup. This enabled us to invert a 2D seismic line in less than five hours of CPU time. We were invited to write a paper on our results that was subsequently accepted for publication. We also carried out a rigorous study to examine the sensitivity and resolution of seismic data to petrophysical parameters. In other words, we developed a full waveform inversion algorithm that estimates petrophysical parameters such as porosity and saturation from pre-stack seismic waveform data. First we used a modified Biot-Gassmann equation to relate petrophysical parameters to elastic parameters. The transformation was validated with a suite of well logs acquired in the deepwater Gulf of Mexico. As a part of this study, we carried out a sensitivity analysis and found that the porosity is very well resolved while the fluid saturation remains insensitive to seismic wave amplitudes. Finally we conducted a joint inversion of pre-stack seismic waveform and production history data. To overcome the computational difficulties we used a simpler waveform modeling algorithm together with an efficient subspace approach. The algorithm was tested on a realistic synthetic data set. We observed that the use of pre-stack seismic data helps tremendously to improve horizontal resolution of porosity maps. Finally, we submitted four publications to refereed technical journals, two refereed extended abstracts to technical conferences
Animal testing using 3D microwave tomography system for breast cancer detection.
Lee, Jong Moon; Son, Sung Ho; Kim, Hyuk Je; Kim, Bo Ra; Choi, Heyng Do; Jeon, Soon Ik
2014-01-01
The three dimensional microwave tomography (3D MT) system of the Electronics and Telecommunications Research Institute (ETRI) comprises an antenna array, transmitting receiving module, switch matrix module and a signal processing component. This system also includes a patient interface bed as well as a 3D reconstruction algorithm. Here, we perform a comparative analysis of image reconstruction results using the assembled system and MRI results, which is used to image the breasts of dogs. Microwave imaging reconstruction results (at 1,500 MHz) obtained using the ETRI 3D MT system are presented. The system provides computationally reliable diagnosis results from the reconstructed MT Image. PMID:25160233
NASA Astrophysics Data System (ADS)
Belyavskii, V. V.; Nikolayev, Yu. I.
2011-01-01
We propose a system for the analysis of magnetotelluric (MT) data, which makes use of the invariant characteristics of the impedance tensor such as the maximum and minimum induction curves and the phase tensor. We examine the coefficients of the appearance and normalization of principal values of the impedance tensor. By the case study for Koryakiya, it is shown that the three-dimensional (3D) mathematical modeling and the Wiese-Parkinson vectors allow one to correct the results of one-dimensional (1D) and two-dimensional (2D) inversion of MT curves. Comparison between model and observed data based on the 1D inversion of MTS curves provides a pictorial view of the distortions of MT curves and their sensitivity to the parameters of a geological cross section.
NASA Astrophysics Data System (ADS)
Pujol, J. M.; Chiu, J. M.
2014-12-01
When applying seismic tomography to local arrival times from an area with a low-velocity sedimentary cover, the effect of the sediments on travel times should be taken into account. If that is not done, the resulting velocity model(s) cannot be assumed to be correct. This fairly obvious statement has been challenged recently by Powell et al. (JGR, 2010), who claimed that the sediments that cover the New Madrid seismic zone (NMSZ, central United States) can be ignored. This claim is examined here and shown to be incorrect. The NMSZ is covered by low-velocity, poorly consolidated sediments (Vp=1.8 km/s, Vs=3), which are underlain by Paleozoic rocks of much higher velocity. In the central NMSZ the sediment thickness varies between about 0.1 and 0.7 km. The JHD analysis of the data collected in that area by a portable network (PANDA) showed that the P- and S-wave station corrections spanned large ranges (0.35 and 0.63 s, respectively, Pujol et al., Eng. Geol., 1997). This study also showed that a Vp/Vs of 3 for the sediments would be too high if the lateral velocity variations were confined to the sedimentary cover. Here we generate synthetic traveltimes for a model with a sedimentary cover having variable depth (as determined from boreholes) underlain by the high-velocity layers in the 1-D model used for the JHD analysis. The synthetic data were generated for the station and event distributions corresponding to the Panda data. The tomographic inversion of the synthetic times produces spurious anomalies in Vp, Vs, and Vp/Vs, from the surface to a depth of 10 km. In addition, the events are mislocated in depth, with errors between 0 and 1 km for most of them. These results should dispel the notion that the effect of the unconsolidated sediments can be ignored. On the other hand, the inversion of the actual Panda data results in velocity anomalies similar to the synthetic anomalies, although larger, which is consistent with the conclusions of Pujol et al. (1997
NASA Astrophysics Data System (ADS)
Tung, Sui; Masterlark, Timothy
2016-05-01
We derive a coseismic slip model of the 2015 Mw7.8 Gorkha earthquake on the basis of GPS and line-of-sight displacements from ALOS-2 descending interferograms, using Green's functions calculated with a 3-D finite element model (FEM). The FEM simulates a nonuniform distribution of elastic material properties and a precise geometric configuration of the irregular topographical surface. The rupturing fault is modeled as a low-angle and north dipping surface within the Main Frontal Thrust along the convergent margin of the Himalayas. The optimal model that inherits heterogeneous material properties provides a significantly better solution than that in a homogenous domain at the 95% confidence interval. The best fit solution for the domain having a nonuniform distribution of material properties reveals a rhombus-shaped slip zone of three composite asperities. Slip is primarily concentrated at a depth of 15 km with both dip-slip (maximum 6.54 m) and strike-slip (maximum 2.0 m) components, giving rise to a geodetic-based moment of 1.09 × 1021 Nm in general agreement with the seismological estimate. The optimal relative weights among GPS and interferometric synthetic aperture radar (InSAR) are deduced from a new method, MC-HVCE which combines a Monte Carlo search and a Helmert Method of Variance Components Estimation. This method determines the relative weights in a systemic approach which preserves the intrinsic solution smoothness. The joint solution is significantly better than those inverted from each individual data set. This methodology allows us to integrate multiple data sets of geodetic observations with seismic tomography, in an effort to achieve a better understanding of seismic ruptures within crustal heterogeneity.
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 Elevation Program—Virtual USA in 3D
Lukas, Vicki; Stoker, J.M.
2016-04-14
The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) uses a laser system called ‘lidar’ (light detection and ranging) to create a virtual reality map of the Nation that is very accurate. 3D maps have many uses with new uses being discovered all the time.
3-D structure and dynamics of microtubule self-organization
NASA Astrophysics Data System (ADS)
Wang, Jing; Ou-Yang, H. Daniel
2008-03-01
Laser scanning confocal microscopy was used to study the dynamics of 3D assemblies spontaneously formed in microtubule (MT) solutions. Microtubule solutions prepared by mixing and incubating tubulin in the presence of GTP and Oregon Green conjugated taxol in PM buffer were placed in long, sub-millimeter thin glass cells by the capillary action. Within 24 hours, starting with a uniform distribution, microtubules were found to be gradually separated into a few large ``buckled'' bundles along the long direction, and in the middle plane, of the sample cell. A well-defined wavelength of the buckling sinusoids was around 510 μm. The cross section of these round bundles was approximately 40 μm in diameter and the lengths were several centimeters. Detailed analysis of the 3-D image within the bundles revealed that each bundle seemed to consist of loosely packed MTs. It appeared that MTs were phase separated resulting from attractive interactions between charged MT fibers. The ``buckling'' behavior could be the result of geometrical constraints of the repulsive cell walls and the repulsive interaction between bundles. Detailed 3-D observations of the dynamic evolution of MT assembly could provide insight to the mechanisms of cellular MT organization and phase separation of charged colloidal rods.
NASA Technical Reports Server (NTRS)
2001-01-01
[figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1 Movie
This 3-D anaglyph image of Mt. St. Helens volcano combines the nadir-looking and back-looking band 3 images of ASTER. To view the image in stereo, you will need blue-red glasses. Make sure to look through the red lens with your left eye. Figure 1: This ASTER image of Mt. St. Helens volcano in Washington was acquired on August 8, 2000 and covers an area of 37 by 51 km. Mount Saint Helens, a volcano in the Cascade Range of southwestern Washington that had been dormant since 1857, began to show signs of renewed activity in early 1980. On 18 May 1980, it erupted with such violence that the top of the mountain was blown off, spewing a cloud of ash and gases that rose to an altitude of 19 kilometers. The blast killed about 60 people and destroyed all life in an area of some 180 square kilometers (some 70 square miles), while a much larger area was covered with ash and debris. It continues to spit forth ash and steam intermittently. As a result of the eruption, the mountain's elevation decreased from 2,950 meters to 2,549 meters. The image is centered at 46.2 degrees north latitude, 122.2 degrees west longitude.
Movie: The simulated fly-over was produced by draping ASTER visible and near infrared image data over a digital topography model, created from ASTER's 3-D stereo bands. The color was computer enhanced to create a natural color image, where the vegetation appears green. The topography has been exaggerated 2 times to enhance the appearance of the relief.
The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.
The Galicia 3D experiment: an Introduction.
NASA Astrophysics Data System (ADS)
Reston, Timothy; Martinez Loriente, Sara; Holroyd, Luke; Merry, Tobias; Sawyer, Dale; Morgan, Julia; Jordan, Brian; Tesi Sanjurjo, Mari; Alexanian, Ara; Shillington, Donna; Gibson, James; Minshull, Tim; Karplus, Marianne; Bayracki, Gaye; Davy, Richard; Klaeschen, Dirk; Papenberg, Cord; Ranero, Cesar; Perez-Gussinye, Marta; Martinez, Miguel
2014-05-01
In June and July 2013, scientists from 8 institutions took part in the Galicia 3D seismic experiment, the first ever crustal -scale academic 3D MCS survey over a rifted margin. The aim was to determine the 3D structure of a critical portion of the west Galicia rifted margin. At this margin, well-defined tilted fault blocks, bound by west-dipping faults and capped by synrift sediments are underlain by a bright reflection, undulating on time sections, termed the S reflector and thought to represent a major detachment fault of some kind. Moving west, the crust thins to zero thickness and mantle is unroofed, as evidence by the "Peridotite Ridge" first reported at this margin, but since observed at many other magma-poor margins. By imaging such a margin in detail, the experiment aimed to resolve the processes controlling crustal thinning and mantle unroofing at a type example magma poor margin. The experiment set out to collect several key datasets: a 3D seismic reflection volume measuring ~20x64km and extending down to ~14s TWT, a 3D ocean bottom seismometer dataset suitable for full wavefield inversion (the recording of the complete 3D seismic shots by 70 ocean bottom instruments), the "mirror imaging" of the crust using the same grid of OBS, a single 2D combined reflection/refraction profile extending to the west to determine the transition from unroofed mantle to true oceanic crust, and the seismic imaging of the water column, calibrated by regular deployment of XBTs to measure the temperature structure of the water column. We collected 1280 km2 of seismic reflection data, consisting of 136533 shots recorded on 1920 channels, producing 260 million seismic traces, each ~ 14s long. This adds up to ~ 8 terabytes of data, representing, we believe, the largest ever academic 3D MCS survey in terms of both the area covered and the volume of data. The OBS deployment was the largest ever within an academic 3D survey.
Three-dimensional controlled-source electromagnetic and magnetotelluric joint inversion
Commer, M.; Newman, G.A.
2009-02-15
The growing use of the controlled-source electromagnetic method (CSEM) and magnetotellurics (MT) for exploration applications has been driving the development of data acquisition technologies, and three-dimensional (3-D) modeling and imaging techniques. However, targeting increasingly complex geological environments also further enhances the problems inherent in large-scale inversion, such as non-uniqueness and resolution issues. In this paper, we report on two techniques to mitigate these problems. We use 3-D joint CSEM and MT inversion to improve the model resolution. To avoid the suppression of the resolution capacities of one data type, and thus to balance the use of inherent, and ideally complementary information content, different data reweighting schemes are proposed. Further, a hybrid model parameterization approach is presented, where traditional cell-based model parameters are used simultaneously within a parametric inversion. The idea is to limit the non-uniqueness problem, typical for 3-D imaging problems, in order to allow for a more focusing inversion. The methods are demonstrated using synthetic data generated from models with a strong practical relevance.
NASA Technical Reports Server (NTRS)
1977-01-01
A market study of a proposed version of a 3-D eyetracker for initial use at NASA's Ames Research Center was made. The commercialization potential of a simplified, less expensive 3-D eyetracker was ascertained. Primary focus on present and potential users of eyetrackers, as well as present and potential manufacturers has provided an effective means of analyzing the prospects for commercialization.
None
2016-07-12
This video provides an overview of the Sandia National Laboratories developed 3-D World Model Building capability that provides users with an immersive, texture rich 3-D model of their environment in minutes using a laptop and color and depth camera.
2013-10-30
This video provides an overview of the Sandia National Laboratories developed 3-D World Model Building capability that provides users with an immersive, texture rich 3-D model of their environment in minutes using a laptop and color and depth camera.
2013-10-01
Earth3D is a computer code designed to allow fast calculation of seismic rays and travel times through a 3D model of the Earth. LLNL is using this for earthquake location and global tomography efforts and such codes are of great interest to the Earth Science community.
[3-D ultrasound in gastroenterology].
Zoller, W G; Liess, H
1994-06-01
Three-dimensional (3D) sonography represents a development of noninvasive diagnostic imaging by real-time two-dimensional (2D) sonography. The use of transparent rotating scans, comparable to a block of glass, generates a 3D effect. The objective of the present study was to optimate 3D presentation of abdominal findings. Additional investigations were made with a new volumetric program to determine the volume of selected findings of the liver. The results were compared with the estimated volumes of 2D sonography and 2D computer tomography (CT). For the processing of 3D images, typical parameter constellations were found for the different findings, which facilitated processing of 3D images. In more than 75% of the cases examined we found an optimal 3D presentation of sonographic findings with respect to the evaluation criteria developed by us for the 3D imaging of processed data. Great differences were found for the estimated volumes of the findings of the liver concerning the three different techniques applied. 3D ultrasound represents a valuable method to judge morphological appearance in abdominal findings. The possibility of volumetric measurements enlarges its potential diagnostic significance. Further clinical investigations are necessary to find out if definite differentiation between benign and malign findings is possible.
NASA Astrophysics Data System (ADS)
Kordy, M.; Wannamaker, P.; Maris, V.; Cherkaev, E.; Hill, G.
2016-01-01
Following the creation described in Part I of a deformable edge finite-element simulator for 3-D magnetotelluric (MT) responses using direct solvers, in Part II we develop an algorithm named HexMT for 3-D regularized inversion of MT data including topography. Direct solvers parallelized on large-RAM, symmetric multiprocessor (SMP) workstations are used also for the Gauss-Newton model update. By exploiting the data-space approach, the computational cost of the model update becomes much less in both time and computer memory than the cost of the forward simulation. In order to regularize using the second norm of the gradient, we factor the matrix related to the regularization term and apply its inverse to the Jacobian, which is done using the MKL PARDISO library. For dense matrix multiplication and factorization related to the model update, we use the PLASMA library which shows very good scalability across processor cores. A synthetic test inversion using a simple hill model shows that including topography can be important; in this case depression of the electric field by the hill can cause false conductors at depth or mask the presence of resistive structure. With a simple model of two buried bricks, a uniform spatial weighting for the norm of model smoothing recovered more accurate locations for the tomographic images compared to weightings which were a function of parameter Jacobians. We implement joint inversion for static distortion matrices tested using the Dublin secret model 2, for which we are able to reduce nRMS to ˜1.1 while avoiding oscillatory convergence. Finally we test the code on field data by inverting full impedance and tipper MT responses collected around Mount St Helens in the Cascade volcanic chain. Among several prominent structures, the north-south trending, eruption-controlling shear zone is clearly imaged in the inversion.
NASA Astrophysics Data System (ADS)
Walsh, J. R.
2004-02-01
The Euro3D RTN is an EU funded Research Training Network to foster the exploitation of 3D spectroscopy in Europe. 3D spectroscopy is a general term for spectroscopy of an area of the sky and derives its name from its two spatial + one spectral dimensions. There are an increasing number of instruments which use integral field devices to achieve spectroscopy of an area of the sky, either using lens arrays, optical fibres or image slicers, to pack spectra of multiple pixels on the sky (``spaxels'') onto a 2D detector. On account of the large volume of data and the special methods required to reduce and analyse 3D data, there are only a few centres of expertise and these are mostly involved with instrument developments. There is a perceived lack of expertise in 3D spectroscopy spread though the astronomical community and its use in the armoury of the observational astronomer is viewed as being highly specialised. For precisely this reason the Euro3D RTN was proposed to train young researchers in this area and develop user tools to widen the experience with this particular type of data in Europe. The Euro3D RTN is coordinated by Martin M. Roth (Astrophysikalisches Institut Potsdam) and has been running since July 2002. The first Euro3D science conference was held in Cambridge, UK from 22 to 23 May 2003. The main emphasis of the conference was, in keeping with the RTN, to expose the work of the young post-docs who are funded by the RTN. In addition the team members from the eleven European institutes involved in Euro3D also presented instrumental and observational developments. The conference was organized by Andy Bunker and held at the Institute of Astronomy. There were over thirty participants and 26 talks covered the whole range of application of 3D techniques. The science ranged from Galactic planetary nebulae and globular clusters to kinematics of nearby galaxies out to objects at high redshift. Several talks were devoted to reporting recent observations with newly
Dawood, A; Marti Marti, B; Sauret-Jackson, V; Darwood, A
2015-12-01
3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery. PMID:26657435
NASA Technical Reports Server (NTRS)
Walatka, Pamela P.; Buning, Pieter G.; Pierce, Larry; Elson, Patricia A.
1990-01-01
PLOT3D is a computer graphics program designed to visualize the grids and solutions of computational fluid dynamics. Seventy-four functions are available. Versions are available for many systems. PLOT3D can handle multiple grids with a million or more grid points, and can produce varieties of model renderings, such as wireframe or flat shaded. Output from PLOT3D can be used in animation programs. The first part of this manual is a tutorial that takes the reader, keystroke by keystroke, through a PLOT3D session. The second part of the manual contains reference chapters, including the helpfile, data file formats, advice on changing PLOT3D, and sample command files.
Dawood, A; Marti Marti, B; Sauret-Jackson, V; Darwood, A
2015-12-01
3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery.
PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITHOUT TURB3D)
NASA Technical Reports Server (NTRS)
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)
NASA Technical Reports Server (NTRS)
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
Unassisted 3D camera calibration
NASA Astrophysics Data System (ADS)
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.
NASA Astrophysics Data System (ADS)
Haefner, David P.; Preece, Bradley L.; Doe, Joshua M.; Burks, Stephen D.
2016-05-01
When evaluated with a spatially uniform irradiance, an imaging sensor exhibits both spatial and temporal variations, which can be described as a three-dimensional (3D) random process considered as noise. In the 1990s, NVESD engineers developed an approximation to the 3D power spectral density (PSD) for noise in imaging systems known as 3D noise. In this correspondence, we describe how the confidence intervals for the 3D noise measurement allows for determination of the sampling necessary to reach a desired precision. We then apply that knowledge to create a smaller cube that can be evaluated spatially across the 2D image giving the noise as a function of position. The method presented here allows for both defective pixel identification and implements the finite sampling correction matrix. In support of the reproducible research effort, the Matlab functions associated with this work can be found on the Mathworks file exchange [1].
NASA Astrophysics Data System (ADS)
Lee-Elkin, Forest
2008-04-01
Three dimensional (3D) autofocus remains a significant challenge for the development of practical 3D multipass radar imaging. The current 2D radar autofocus methods are not readily extendable across sensor passes. We propose a general framework that allows a class of data adaptive solutions for 3D auto-focus across passes with minimal constraints on the scene contents. The key enabling assumption is that portions of the scene are sparse in elevation which reduces the number of free variables and results in a system that is simultaneously solved for scatterer heights and autofocus parameters. The proposed method extends 2-pass interferometric synthetic aperture radar (IFSAR) methods to an arbitrary number of passes allowing the consideration of scattering from multiple height locations. A specific case from the proposed autofocus framework is solved and demonstrates autofocus and coherent multipass 3D estimation across the 8 passes of the "Gotcha Volumetric SAR Data Set" X-Band radar data.
Rich, D.O.; Pope, S.C.; DeLapp, J.G.
1994-10-01
In April, a 128 PE Cray T3D was installed at Los Alamos National Laboratory`s Advanced Computing Laboratory as part of the DOE`s High-Performance Parallel Processor Program (H4P). In conjunction with CRI, the authors implemented a 30 day acceptance test. The test was constructed in part to help them understand the strengths and weaknesses of the T3D. In this paper, they briefly describe the H4P and its goals. They discuss the design and implementation of the T3D acceptance test and detail issues that arose during the test. They conclude with a set of system requirements that must be addressed as the T3D system evolves.
Combinatorial 3D Mechanical Metamaterials
NASA Astrophysics Data System (ADS)
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.
LASTRAC.3d: Transition Prediction in 3D Boundary Layers
NASA Technical Reports Server (NTRS)
Chang, Chau-Lyan
2004-01-01
Langley Stability and Transition Analysis Code (LASTRAC) is a general-purpose, physics-based transition prediction code released by NASA for laminar flow control studies and transition research. This paper describes the LASTRAC extension to general three-dimensional (3D) boundary layers such as finite swept wings, cones, or bodies at an angle of attack. The stability problem is formulated by using a body-fitted nonorthogonal curvilinear coordinate system constructed on the body surface. The nonorthogonal coordinate system offers a variety of marching paths and spanwise waveforms. In the extreme case of an infinite swept wing boundary layer, marching with a nonorthogonal coordinate produces identical solutions to those obtained with an orthogonal coordinate system using the earlier release of LASTRAC. Several methods to formulate the 3D parabolized stability equations (PSE) are discussed. A surface-marching procedure akin to that for 3D boundary layer equations may be used to solve the 3D parabolized disturbance equations. On the other hand, the local line-marching PSE method, formulated as an easy extension from its 2D counterpart and capable of handling the spanwise mean flow and disturbance variation, offers an alternative. A linear stability theory or parabolized stability equations based N-factor analysis carried out along the streamline direction with a fixed wavelength and downstream-varying spanwise direction constitutes an efficient engineering approach to study instability wave evolution in a 3D boundary layer. The surface-marching PSE method enables a consistent treatment of the disturbance evolution along both streamwise and spanwise directions but requires more stringent initial conditions. Both PSE methods and the traditional LST approach are implemented in the LASTRAC.3d code. Several test cases for tapered or finite swept wings and cones at an angle of attack are discussed.
NASA Astrophysics Data System (ADS)
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
NASA Astrophysics Data System (ADS)
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.
Advanced 3D inverse method for designing turbomachine blades
Dang, T.
1995-10-01
To meet the goal of 60% plant-cycle efficiency or better set in the ATS Program for baseload utility scale power generation, several critical technologies need to be developed. One such need is the improvement of component efficiencies. This work addresses the issue of improving the performance of turbo-machine components in gas turbines through the development of an advanced three-dimensional and viscous blade design system. This technology is needed to replace some elements in current design systems that are based on outdated technology.
Remote 3D Medical Consultation
NASA Astrophysics Data System (ADS)
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.
NASA Technical Reports Server (NTRS)
2002-01-01
In 1999, Genex submitted a proposal to Stennis Space Center for a volumetric 3-D display technique that would provide multiple users with a 360-degree perspective to simultaneously view and analyze 3-D data. The futuristic capabilities of the VolumeViewer(R) have offered tremendous benefits to commercial users in the fields of medicine and surgery, air traffic control, pilot training and education, computer-aided design/computer-aided manufacturing, and military/battlefield management. The technology has also helped NASA to better analyze and assess the various data collected by its satellite and spacecraft sensors. Genex capitalized on its success with Stennis by introducing two separate products to the commercial market that incorporate key elements of the 3-D display technology designed under an SBIR contract. The company Rainbow 3D(R) imaging camera is a novel, three-dimensional surface profile measurement system that can obtain a full-frame 3-D image in less than 1 second. The third product is the 360-degree OmniEye(R) video system. Ideal for intrusion detection, surveillance, and situation management, this unique camera system offers a continuous, panoramic view of a scene in real time.
Au, Anthony K; Huynh, Wilson; Horowitz, Lisa F; Folch, Albert
2016-03-14
The advent of soft lithography allowed for an unprecedented expansion in the field of microfluidics. However, the vast majority of PDMS microfluidic devices are still made with extensive manual labor, are tethered to bulky control systems, and have cumbersome user interfaces, which all render commercialization difficult. On the other hand, 3D printing has begun to embrace the range of sizes and materials that appeal to the developers of microfluidic devices. Prior to fabrication, a design is digitally built as a detailed 3D CAD file. The design can be assembled in modules by remotely collaborating teams, and its mechanical and fluidic behavior can be simulated using finite-element modeling. As structures are created by adding materials without the need for etching or dissolution, processing is environmentally friendly and economically efficient. We predict that in the next few years, 3D printing will replace most PDMS and plastic molding techniques in academia.
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.
Joint Inversion Modelling of Geophysical Data From Lough Neagh Basin
NASA Astrophysics Data System (ADS)
Vozar, J.; Moorkamp, M.; Jones, A. G.; Rath, V.; Muller, M. R.
2015-12-01
Multi-dimensional modelling of geophysical data collected in the Lough Neagh Basin is presented in the frame of the IRETHERM project. The Permo-Triassic Lough Neagh Basin, situated in the southeastern part of Northern Ireland, exhibits elevated geothermal gradient (~30 °C/km) in the exploratory drilled boreholes. This is taken to indicate good geothermal exploitation potential in the Sherwood Sandstone aquifer for heating, and possibly even electricity production, purposes. We have used a 3-D joint inversion framework for modelling the magnetotelluric (MT) and gravity data collected to the north of the Lough Neagh to derive robust subsurface geological models. Comprehensive supporting geophysical and geological data (e.g. borehole logs and reflection seismic images) have been used in order to analyze and model the MT and gravity data. The geophysical data sets were provided by the Geological Survey of Northern Ireland (GSNI). Considering correct objective function weighting in favor of noise-free MT response functions is particularly important in joint inversion. There is no simple way how to correct distortion effects the 3-D responses as can be done in 1-D or 2-D case. We have used the Tellus Project airborne EM data to constrain magnetotelluric data and correct them for near surface effects. The shallow models from airborne data are used to constrain the uppermost part of 3-D inversion model. Preliminary 3-D joint inversion modeling reveals that the Sherwood Sandstone Group and the Permian Sandstone Formation are imaged as a conductive zone at the depth range of 500 m to 2000 m with laterally varying thickness, depth, and conductance. The conductive target sediments become shallower and thinner to the north and they are laterally continuous. To obtain better characterization of thermal transport properties of investigated area we used porosity and resistivity data from the Annaghmore and Ballymacilroy boreholes to estimate the relations between porosity
ERIC Educational Resources Information Center
Manos, Harry
2016-01-01
Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the "TPT" theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity…
2007-07-20
This software distribution contains MATLAB and C++ code to enable identity verification using 3D images that may or may not contain a texture component. The code is organized to support system performance testing and system capability demonstration through the proper configuration of the available user interface. Using specific algorithm parameters the face recognition system has been demonstrated to achieve a 96.6% verification rate (Pd) at 0.001 false alarm rate. The system computes robust facial featuresmore » of a 3D normalized face using Principal Component Analysis (PCA) and Fisher Linear Discriminant Analysis (FLDA). A 3D normalized face is obtained by alighning each face, represented by a set of XYZ coordinated, to a scaled reference face using the Iterative Closest Point (ICP) algorithm. The scaled reference face is then deformed to the input face using an iterative framework with parameters that control the deformed surface regulation an rate of deformation. A variety of options are available to control the information that is encoded by the PCA. Such options include the XYZ coordinates, the difference of each XYZ coordinates from the reference, the Z coordinate, the intensity/texture values, etc. In addition to PCA/FLDA feature projection this software supports feature matching to obtain similarity matrices for performance analysis. In addition, this software supports visualization of the STL, MRD, 2D normalized, and PCA synthetic representations in a 3D environment.« less
Russ, Trina; Koch, Mark; Koudelka, Melissa; Peters, Ralph; Little, Charles; Boehnen, Chris; Peters, Tanya
2007-07-20
This software distribution contains MATLAB and C++ code to enable identity verification using 3D images that may or may not contain a texture component. The code is organized to support system performance testing and system capability demonstration through the proper configuration of the available user interface. Using specific algorithm parameters the face recognition system has been demonstrated to achieve a 96.6% verification rate (Pd) at 0.001 false alarm rate. The system computes robust facial features of a 3D normalized face using Principal Component Analysis (PCA) and Fisher Linear Discriminant Analysis (FLDA). A 3D normalized face is obtained by alighning each face, represented by a set of XYZ coordinated, to a scaled reference face using the Iterative Closest Point (ICP) algorithm. The scaled reference face is then deformed to the input face using an iterative framework with parameters that control the deformed surface regulation an rate of deformation. A variety of options are available to control the information that is encoded by the PCA. Such options include the XYZ coordinates, the difference of each XYZ coordinates from the reference, the Z coordinate, the intensity/texture values, etc. In addition to PCA/FLDA feature projection this software supports feature matching to obtain similarity matrices for performance analysis. In addition, this software supports visualization of the STL, MRD, 2D normalized, and PCA synthetic representations in a 3D environment.
3D Printing: Exploring Capabilities
ERIC Educational Resources Information Center
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…
TACO3D. 3-D Finite Element Heat Transfer Code
Mason, W.E.
1992-03-04
TACO3D is a three-dimensional, finite-element program for heat transfer analysis. An extension of the two-dimensional TACO program, it can perform linear and nonlinear analyses and can be used to solve either transient or steady-state problems. The program accepts time-dependent or temperature-dependent material properties, and materials may be isotropic or orthotropic. A variety of time-dependent and temperature-dependent boundary conditions and loadings are available including temperature, flux, convection, and radiation boundary conditions and internal heat generation. Additional specialized features treat enclosure radiation, bulk nodes, and master/slave internal surface conditions (e.g., contact resistance). Data input via a free-field format is provided. A user subprogram feature allows for any type of functional representation of any independent variable. A profile (bandwidth) minimization option is available. The code is limited to implicit time integration for transient solutions. TACO3D has no general mesh generation capability. Rows of evenly-spaced nodes and rows of sequential elements may be generated, but the program relies on separate mesh generators for complex zoning. TACO3D does not have the ability to calculate view factors internally. Graphical representation of data in the form of time history and spatial plots is provided through links to the POSTACO and GRAPE postprocessor codes.
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.
Reduction of thermal conductivity by nanoscale 3D phononic crystal.
Yang, Lina; Yang, Nuo; Li, Baowen
2013-01-01
We studied how the period length and the mass ratio affect the thermal conductivity of isotopic nanoscale three-dimensional (3D) phononic crystal of Si. Simulation results by equilibrium molecular dynamics show isotopic nanoscale 3D phononic crystals can significantly reduce the thermal conductivity of bulk Si at high temperature (1000 K), which leads to a larger ZT than unity. The thermal conductivity decreases as the period length and mass ratio increases. The phonon dispersion curves show an obvious decrease of group velocities in 3D phononic crystals. The phonon's localization and band gap is also clearly observed in spectra of normalized inverse participation ratio in nanoscale 3D phononic crystal.
Reduction of Thermal Conductivity by Nanoscale 3D Phononic Crystal
Yang, Lina; Yang, Nuo; Li, Baowen
2013-01-01
We studied how the period length and the mass ratio affect the thermal conductivity of isotopic nanoscale three-dimensional (3D) phononic crystal of Si. Simulation results by equilibrium molecular dynamics show isotopic nanoscale 3D phononic crystals can significantly reduce the thermal conductivity of bulk Si at high temperature (1000 K), which leads to a larger ZT than unity. The thermal conductivity decreases as the period length and mass ratio increases. The phonon dispersion curves show an obvious decrease of group velocities in 3D phononic crystals. The phonon's localization and band gap is also clearly observed in spectra of normalized inverse participation ratio in nanoscale 3D phononic crystal. PMID:23378898
Forensic 3D scene reconstruction
NASA Astrophysics Data System (ADS)
Little, Charles Q.; Small, Daniel E.; Peters, Ralph R.; Rigdon, J. B.
2000-05-01
Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and contribute quantitative measurements such as accurate relative positioning of crime scene objects, would be an asset to law enforcement agents in collecting and recording significant forensic data. The purpose of this project is to develop a fieldable 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.
3D Printable Graphene Composite.
Wei, Xiaojun; Li, Dong; Jiang, Wei; Gu, Zheming; Wang, Xiaojuan; Zhang, Zengxing; Sun, Zhengzong
2015-07-08
In human being's history, both the Iron Age and Silicon Age thrived after a matured massive processing technology was developed. Graphene is the most recent superior material which could potentially initialize another new material Age. However, while being exploited to its full extent, conventional processing methods fail to provide a link to today's personalization tide. New technology should be ushered in. Three-dimensional (3D) printing fills the missing linkage between graphene materials and the digital mainstream. Their alliance could generate additional stream to push the graphene revolution into a new phase. Here we demonstrate for the first time, a graphene composite, with a graphene loading up to 5.6 wt%, can be 3D printable into computer-designed models. The composite's linear thermal coefficient is below 75 ppm·°C(-1) from room temperature to its glass transition temperature (Tg), which is crucial to build minute thermal stress during the printing process.
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.
NASA Technical Reports Server (NTRS)
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.
3D light scanning macrography.
Huber, D; Keller, M; Robert, D
2001-08-01
The technique of 3D light scanning macrography permits the non-invasive surface scanning of small specimens at magnifications up to 200x. Obviating both the problem of limited depth of field inherent to conventional close-up macrophotography and the metallic coating required by scanning electron microscopy, 3D light scanning macrography provides three-dimensional digital images of intact specimens without the loss of colour, texture and transparency information. This newly developed technique offers a versatile, portable and cost-efficient method for the non-invasive digital and photographic documentation of small objects. Computer controlled device operation and digital image acquisition facilitate fast and accurate quantitative morphometric investigations, and the technique offers a broad field of research and educational applications in biological, medical and materials sciences. PMID:11489078
[Real time 3D echocardiography
NASA Technical Reports Server (NTRS)
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.
[Real time 3D echocardiography].
Bauer, F; Shiota, T; Thomas, J D
2001-07-01
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. PMID:11494630
DYNA3D. Explicit 3-d Hydrodynamic FEM Program
Whirley, R.G.; Englemann, B.E. )
1993-11-30
DYNA3D is an explicit, three-dimensional, finite element program for analyzing the large deformation dynamic response of inelastic solids and structures. DYNA3D contains 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, thermoelastoplastic, 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, inviscid two invariant geologic cap, orthotropic crushable model, Moonsy-Rivlin rubber, resultant plasticity, closed form update shell plasticity, and Frazer-Nash rubber model. The hydrodynamic material models determine only the deviatoric stresses. Pressure is determined by one of 10 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 interface data for contact surfaces.
GPU-Accelerated Denoising in 3D (GD3D)
2013-10-01
The raw computational power GPU Accelerators enables fast denoising of 3D MR images using bilateral filtering, anisotropic diffusion, and non-local means. This software addresses two facets of this promising application: what tuning is necessary to achieve optimal performance on a modern GPU? And what parameters yield the best denoising results in practice? To answer the first question, the software performs an autotuning step to empirically determine optimal memory blocking on the GPU. To answer themore » second, it performs a sweep of algorithm parameters to determine the combination that best reduces the mean squared error relative to a noiseless reference image.« less
Shaverdashvili, Khvaramze; Zhang, Keman; Osman, Iman; Honda, Kord; Jobava, Rauli; Bedogni, Barbara
2015-01-01
Metastatic melanoma is the deadliest of all skin cancers. Despite progress in diagnostics and treatment of melanoma, the prognosis for metastatic patients remains poor. We previously showed that Membrane-type 1 Matrix Metalloproteinase (MT1-MMP) is one of the drivers of melanoma metastasis. Classically, MT1-MMP regulates a verity of cellular functions including cell-to-cell interaction and cell-to-matrix communication. Recently, MT1-MMP has been found to also modulate gene expression. To specifically assess MT1-MMP dependent gene regulation in melanoma, microarray gene expression analysis was performed in a melanoma cell line whose metastatic properties depend on the activity of MT1-MMP. We identified the tumor suppressor gene SPRY4 as a new transcriptional target of MT1-MMP that is negatively regulated by the protease. Knockdown of MT1-MMP enhances SPRY4 expression at the mRNA and protein level. SPRY4 expression inversely correlates with that of MT1-MMP in melanoma samples and importantly, correlates with melanoma patient survival. SPRY4 modulates MT1-MMP dependent cell migration such that inhibition of SPRY4 rescues cell migration that has been impaired by MT1-MMP knock down. MT1-MMP decreases SPRY4 in part through an MMP2/RAC1 axis we previously show promotes cell motility downstream of MT1-MMP. These results identify the tumor suppressor SPRY4 as a novel molecular effector of MT1-MMP affecting melanoma cell motility. PMID:26392417
NASA Astrophysics Data System (ADS)
Kent, G. M.; Harding, A. J.; Babcock, J. M.; Orcutt, J. A.; Bazin, S.; Singh, S.; Detrick, R. S.; Canales, J. P.; Carbotte, S. M.; Diebold, J.
2002-12-01
Multichannel seismic (MCS) images of crustal magma chambers are ideal targets for advanced visualization techniques. In the mid-ocean ridge environment, reflections originating at the melt-lens are well separated from other reflection boundaries, such as the seafloor, layer 2A and Moho, which enables the effective use of transparency filters. 3-D visualization of seismic reflectivity falls into two broad categories: volume and surface rendering. Volumetric-based visualization is an extremely powerful approach for the rapid exploration of very dense 3-D datasets. These 3-D datasets are divided into volume elements or voxels, which are individually color coded depending on the assigned datum value; the user can define an opacity filter to reject plotting certain voxels. This transparency allows the user to peer into the data volume, enabling an easy identification of patterns or relationships that might have geologic merit. Multiple image volumes can be co-registered to look at correlations between two different data types (e.g., amplitude variation with offsets studies), in a manner analogous to draping attributes onto a surface. In contrast, surface visualization of seismic reflectivity usually involves producing "fence" diagrams of 2-D seismic profiles that are complemented with seafloor topography, along with point class data, draped lines and vectors (e.g. fault scarps, earthquake locations and plate-motions). The overlying seafloor can be made partially transparent or see-through, enabling 3-D correlations between seafloor structure and seismic reflectivity. Exploration of 3-D datasets requires additional thought when constructing and manipulating these complex objects. As numbers of visual objects grow in a particular scene, there is a tendency to mask overlapping objects; this clutter can be managed through the effective use of total or partial transparency (i.e., alpha-channel). In this way, the co-variation between different datasets can be investigated
a Fast Method for Measuring the Similarity Between 3d Model and 3d Point Cloud
NASA Astrophysics Data System (ADS)
Zhang, Zongliang; Li, Jonathan; Li, Xin; Lin, Yangbin; Zhang, Shanxin; Wang, Cheng
2016-06-01
This paper proposes a fast method for measuring the partial Similarity between 3D Model and 3D point Cloud (SimMC). It is crucial to measure SimMC for many point cloud-related applications such as 3D object retrieval and inverse procedural modelling. In our proposed method, the surface area of model and the Distance from Model to point Cloud (DistMC) are exploited as measurements to calculate SimMC. Here, DistMC is defined as the weighted distance of the distances between points sampled from model and point cloud. Similarly, Distance from point Cloud to Model (DistCM) is defined as the average distance of the distances between points in point cloud and model. In order to reduce huge computational burdens brought by calculation of DistCM in some traditional methods, we define SimMC as the ratio of weighted surface area of model to DistMC. Compared to those traditional SimMC measuring methods that are only able to measure global similarity, our method is capable of measuring partial similarity by employing distance-weighted strategy. Moreover, our method is able to be faster than other partial similarity assessment methods. We demonstrate the superiority of our method both on synthetic data and laser scanning data.
NASA Astrophysics Data System (ADS)
Maris, Virginie
An existing 3-D magnetotelluric (MT) inversion program written for a single processor personal computer (PC) has been modified and parallelized using OpenMP, in order to run the program efficiently on a multicore workstation. The program uses the Gauss-Newton inversion algorithm based on a staggered-grid finite-difference forward problem, requiring explicit calculation of the Frechet derivatives. The most time-consuming tasks are calculating the derivatives and determining the model parameters at each iteration. Forward modeling and derivative calculations are parallelized by assigning the calculations for each frequency to separate threads, which execute concurrently. Model parameters are obtained by factoring the Hessian using the LDLT method, implemented using a block-cyclic algorithm and compact storage. MT data from 102 tensor stations over the East Flank of the Coso Geothermal Field, California are inverted. Less than three days are required to invert the dataset for ˜ 55,000 inversion parameters on a 2.66 GHz 8-CPU PC with 16 GB of RAM. Inversion results, recovered from a halfspace rather than initial 2-D inversions, qualitatively resemble models from massively parallel 3-D inversion by other researchers and overall, exhibit an improved fit. A steeply west-dipping conductor under the western East Flank is tentatively correlated with a zone of high-temperature ionic fluids based on known well production and lost circulation intervals. Beneath the Main Field, vertical and north-trending shallow conductors are correlated with geothermal producing intervals as well.
Interactive 3D Mars Visualization
NASA Technical Reports Server (NTRS)
Powell, Mark W.
2012-01-01
The Interactive 3D Mars Visualization system provides high-performance, immersive visualization of satellite and surface vehicle imagery of Mars. The software can be used in mission operations to provide the most accurate position information for the Mars rovers to date. When integrated into the mission data pipeline, this system allows mission planners to view the location of the rover on Mars to 0.01-meter accuracy with respect to satellite imagery, with dynamic updates to incorporate the latest position information. Given this information so early in the planning process, rover drivers are able to plan more accurate drive activities for the rover than ever before, increasing the execution of science activities significantly. Scientifically, this 3D mapping information puts all of the science analyses to date into geologic context on a daily basis instead of weeks or months, as was the norm prior to this contribution. This allows the science planners to judge the efficacy of their previously executed science observations much more efficiently, and achieve greater science return as a result. The Interactive 3D Mars surface view is a Mars terrain browsing software interface that encompasses the entire region of exploration for a Mars surface exploration mission. The view is interactive, allowing the user to pan in any direction by clicking and dragging, or to zoom in or out by scrolling the mouse or touchpad. This set currently includes tools for selecting a point of interest, and a ruler tool for displaying the distance between and positions of two points of interest. The mapping information can be harvested and shared through ubiquitous online mapping tools like Google Mars, NASA WorldWind, and Worldwide Telescope.
NASA Technical Reports Server (NTRS)
2004-01-01
This 3-D cylindrical-perspective mosaic taken by the navigation camera on the Mars Exploration Rover Spirit on sol 82 shows the view south of the large crater dubbed 'Bonneville.' The rover will travel toward the Columbia Hills, seen here at the upper left. The rock dubbed 'Mazatzal' and the hole the rover drilled in to it can be seen at the lower left. The rover's position is referred to as 'Site 22, Position 32.' This image was geometrically corrected to make the horizon appear flat.
NASA Astrophysics Data System (ADS)
Manos, Harry
2016-03-01
Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the TPT theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity well tailored to specific class lessons. Most of the supplies are readily available in the home or at school: rubbing alcohol, a rag, two colors of spray paint, art brushes, and masking tape. The cost of these supplies, if you don't have them, is less than 20.
Love, Lonnie
2015-01-09
ORNL's newly printed 3D Shelby Cobra was showcased at the 2015 NAIAS in Detroit. This "laboratory on wheels" uses the Shelby Cobra design, celebrating the 50th anniversary of this model and honoring the first vehicle to be voted a national monument. The Shelby was printed at the Department of Energy’s Manufacturing Demonstration Facility at ORNL using the BAAM (Big Area Additive Manufacturing) machine and is intended as a “plug-n-play” laboratory on wheels. The Shelby will allow research and development of integrated components to be tested and enhanced in real time, improving the use of sustainable, digital manufacturing solutions in the automotive industry.
3-D Printed Asteroids for Outreach Astronomy Education
NASA Astrophysics Data System (ADS)
Russell, April
2015-11-01
3-D printed asteroids provide new opportunities for outreach astronomy education due to their low cost, interactive potential, and high interest value. Telescopes are expensive, bulky, fragile, and cannot be used effectively during the day. 3-D printing of asteroids combines exciting new technology with astronomy, appealing to a broader audience. The printed models are scientifically accurate, as their shapes have been modeled using light-curve inversion techniques using and occultation data to provide a jumping off point for discussions of these advanced and exciting topics.
Positional Awareness Map 3D (PAM3D)
NASA Technical Reports Server (NTRS)
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.
3D acoustic atmospheric tomography
NASA Astrophysics Data System (ADS)
Rogers, Kevin; Finn, Anthony
2014-10-01
This paper presents a method for tomographically reconstructing spatially varying 3D atmospheric temperature profiles and wind velocity fields based. Measurements of the acoustic signature measured onboard a small Unmanned Aerial Vehicle (UAV) are compared to ground-based observations of the same signals. The frequency-shifted signal variations are then used to estimate the acoustic propagation delay between the UAV and the ground microphones, which are also affected by atmospheric temperature and wind speed vectors along each sound ray path. The wind and temperature profiles are modelled as the weighted sum of Radial Basis Functions (RBFs), which also allow local meteorological measurements made at the UAV and ground receivers to supplement any acoustic observations. Tomography is used to provide a full 3D reconstruction/visualisation of the observed atmosphere. The technique offers observational mobility under direct user control and the capacity to monitor hazardous atmospheric environments, otherwise not justifiable on the basis of cost or risk. This paper summarises the tomographic technique and reports on the results of simulations and initial field trials. The technique has practical applications for atmospheric research, sound propagation studies, boundary layer meteorology, air pollution measurements, analysis of wind shear, and wind farm surveys.
NASA Astrophysics Data System (ADS)
Laubenstein, John; Cockream, Kandi
2009-05-01
3D spacetime was developed by the IWPD Scale Metrics (SM) team using a coordinate system that translates n dimensions to n-1. 4-vectors are expressed in 3D along with a scaling factor representing time. Time is not orthogonal to the three spatial dimensions, but rather in alignment with an object's axis-of-motion. We have defined this effect as the object's ``orientation'' (X). The SM orientation (X) is equivalent to the orientation of the 4-velocity vector positioned tangent to its worldline, where X-1=θ+1 and θ is the angle of the 4-vector relative to the axis-of -motion. Both 4-vectors and SM appear to represent valid conceptualizations of the relationship between space and time. Why entertain SM? Scale Metrics gravity is quantized and may suggest a path for the full unification of gravitation with quantum theory. SM has been tested against current observation and is in agreement with the age of the universe, suggests a physical relationship between dark energy and dark matter, is in agreement with the accelerating expansion rate of the universe, contributes to the understanding of the fine-structure constant and provides a physical explanation of relativistic effects.
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.
3D medical thermography device
NASA Astrophysics Data System (ADS)
Moghadam, Peyman
2015-05-01
In this paper, a novel handheld 3D medical thermography system is introduced. The proposed system consists of a thermal-infrared camera, a color camera and a depth camera rigidly attached in close proximity and mounted on an ergonomic handle. As a practitioner holding the device smoothly moves it around the human body parts, the proposed system generates and builds up a precise 3D thermogram model by incorporating information from each new measurement in real-time. The data is acquired in motion, thus it provides multiple points of view. When processed, these multiple points of view are adaptively combined by taking into account the reliability of each individual measurement which can vary due to a variety of factors such as angle of incidence, distance between the device and the subject and environmental sensor data or other factors influencing a confidence of the thermal-infrared data when captured. Finally, several case studies are presented to support the usability and performance of the proposed system.
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 Printable Graphene Composite
Wei, Xiaojun; Li, Dong; Jiang, Wei; Gu, Zheming; Wang, Xiaojuan; Zhang, Zengxing; Sun, Zhengzong
2015-01-01
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. PMID:26153673
3D Printable Graphene Composite
NASA Astrophysics Data System (ADS)
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.
Larry Lawrence; Bruce Miller
2004-09-01
The Lott Ranch 3D seismic prospect located in Garza County, Texas is a project initiated in September of 1991 by the J.M. Huber Corp., a petroleum exploration and production company. By today's standards the 126 square mile project does not seem monumental, however at the time it was conceived it was the most intensive land 3D project ever attempted. Acquisition began in September of 1991 utilizing GEO-SEISMIC, INC., a seismic data contractor. The field parameters were selected by J.M. Huber, and were of a radical design. The recording instruments used were GeoCor IV amplifiers designed by Geosystems Inc., which record the data in signed bit format. It would not have been practical, if not impossible, to have processed the entire raw volume with the tools available at that time. The end result was a dataset that was thought to have little utility due to difficulties in processing the field data. In 1997, Yates Energy Corp. located in Roswell, New Mexico, formed a partnership to further develop the project. Through discussions and meetings with Pinnacle Seismic, it was determined that the original Lott Ranch 3D volume could be vastly improved upon reprocessing. Pinnacle Seismic had shown the viability of improving field-summed signed bit data on smaller 2D and 3D projects. Yates contracted Pinnacle Seismic Ltd. to perform the reprocessing. This project was initiated with high resolution being a priority. Much of the potential resolution was lost through the initial summing of the field data. Modern computers that are now being utilized have tremendous speed and storage capacities that were cost prohibitive when this data was initially processed. Software updates and capabilities offer a variety of quality control and statics resolution, which are pertinent to the Lott Ranch project. The reprocessing effort was very successful. The resulting processed data-set was then interpreted using modern PC-based interpretation and mapping software. Production data, log data
NASA Astrophysics Data System (ADS)
Ogaya, X.; Queralt, P.; Ledo, J.; Marcuello, A.; Jones, A. G.
2012-04-01
The work presented here is a component of an on-going project in the framework of establishing a Technical Development Plant (PDT) for carbon dioxide (CO2) storage in a deep saline aquifer. The Research Laboratory is located at the Spanish town of Hontomín, and the project is funded by Fundación Ciudad de la Energía-CIUDEN (http://www.ciuden.es) on behalf of the Spanish Government. In this setting, magnetotelluric (MT) data are providing a baseline model for estimating CO2 plume distribution after injection. The bulk electrical resistivity of rocks is expected to increase significantly due to the presence of CO2 inside the pores of the reservoir rock since the effective volume available for the ionic transport will be reduced. We present the preliminary results of the electromagnetic characterization of the Hontomín site. In total, 109 broadband magnetotelluric (BBMT) soundings were acquired in the area covering an extent of 3 x 4 km2. The data are organized mainly along five north-south profiles, each of around 4 km in length, in the period range of 15 to 4096 Hz. The stations were deployed at approximately 200 m intervals, recording data during 24 to 48 hours, and the average distance between profiles was 500 m. The instrumentation consisted of Metronix ADU06, Metronix ADU07 and Phoenix V8. A remote reference station was permanently placed around 20 km away from the study area. Different robust processing codes using remote reference methods have been tested and used at all stations to derive optimal MT responses. The 3D electrical resistivity model of the subsurface is being computed using different 3D inversion codes: commercial 3D inversion of Winglink® (Mackie and Madden, 1993), WSINV3DMT (Siripunvaraporn et al., 2005) and modEM (Egbert and Kelbert, 2012). The model is discretized on 73 x 114 x 113-layer grid and the inversions were undertaken using the 4 elements of the impedance tensor (8 responses) and more than 16 periods in the range of 0.001 to 10
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 (<10 mg cm(-3) ) 3D printed graphene aerogel presents superelastic and high electrical conduction.
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 (<10 mg cm(-3) ) 3D printed graphene aerogel presents superelastic and high electrical conduction. PMID:26861680
Sinclair, Michael B
2012-01-05
ShowMe3D is a data visualization graphical user interface specifically designed for use with hyperspectral image obtained from the Hyperspectral Confocal Microscope. The program allows the user to select and display any single image from a three dimensional hyperspectral image stack. By moving a slider control, the user can easily move between images of the stack. The user can zoom into any region of the image. The user can select any pixel or region from the displayed image and display the fluorescence spectrum associated with that pixel or region. The user can define up to 3 spectral filters to apply to the hyperspectral image and view the image as it would appear from a filter-based confocal microscope. The user can also obtain statistics such as intensity average and variance from selected regions.
Conducting Polymer 3D Microelectrodes
Sasso, Luigi; Vazquez, Patricia; Vedarethinam, Indumathi; Castillo-León, Jaime; Emnéus, Jenny; Svendsen, Winnie E.
2010-01-01
Conducting polymer 3D microelectrodes have been fabricated for possible future neurological applications. A combination of micro-fabrication techniques and chemical polymerization methods has been used to create pillar electrodes in polyaniline and polypyrrole. The thin polymer films obtained showed uniformity and good adhesion to both horizontal and vertical surfaces. Electrodes in combination with metal/conducting polymer materials have been characterized by cyclic voltammetry and the presence of the conducting polymer film has shown to increase the electrochemical activity when compared 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. PMID:22163508
2012-01-05
ShowMe3D is a data visualization graphical user interface specifically designed for use with hyperspectral image obtained from the Hyperspectral Confocal Microscope. The program allows the user to select and display any single image from a three dimensional hyperspectral image stack. By moving a slider control, the user can easily move between images of the stack. The user can zoom into any region of the image. The user can select any pixel or region from themore » displayed image and display the fluorescence spectrum associated with that pixel or region. The user can define up to 3 spectral filters to apply to the hyperspectral image and view the image as it would appear from a filter-based confocal microscope. The user can also obtain statistics such as intensity average and variance from selected regions.« less
NASA Technical Reports Server (NTRS)
2009-01-01
wavelengths. Since the amount 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
NASA Technical Reports Server (NTRS)
2009-01-01
wavelengths. Since the amount 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
Template-Directed Directionally Solidified 3D Mesostructured AgCl-KCl Eutectic Photonic Crystals.
Kim, Jinwoo; Aagesen, Larry K; Choi, Jun Hee; Choi, Jaewon; Kim, Ha Seong; Liu, Jinyun; Cho, Chae-Ryong; Kang, Jin Gu; Ramazani, Ali; Thornton, Katsuyo; Braun, Paul V
2015-08-19
3D mesostructured AgCl-KCl photonic crystals emerge from colloidal templating of eutectic solidification. Solvent removal of the KCl phase results in a mesostructured AgCl inverse opal. The 3D-template-induced confinement leads to the emergence of a complex microstructure. The 3D mesostructured eutectic photonic crystals have a large stop band ranging from the near-infrared to the visible tuned by the processing.
3D multiplexed immunoplasmonics microscopy
NASA Astrophysics Data System (ADS)
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
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
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.
Alán, Lukáš; Špaček, Tomáš; Ježek, Petr
2016-07-01
Data segmentation and object rendering is required for localization super-resolution microscopy, fluorescent photoactivation localization microscopy (FPALM), and direct stochastic optical reconstruction microscopy (dSTORM). We developed and validated methods for segmenting objects based on Delaunay triangulation in 3D space, followed by facet culling. We applied them to visualize mitochondrial nucleoids, which confine DNA in complexes with mitochondrial (mt) transcription factor A (TFAM) and gene expression machinery proteins, such as mt single-stranded-DNA-binding protein (mtSSB). Eos2-conjugated TFAM visualized nucleoids in HepG2 cells, which was compared with dSTORM 3D-immunocytochemistry of TFAM, mtSSB, or DNA. The localized fluorophores of FPALM/dSTORM data were segmented using Delaunay triangulation into polyhedron models and by principal component analysis (PCA) into general PCA ellipsoids. The PCA ellipsoids were normalized to the smoothed volume of polyhedrons or by the net unsmoothed Delaunay volume and remodeled into rotational ellipsoids to obtain models, termed DVRE. The most frequent size of ellipsoid nucleoid model imaged via TFAM was 35 × 45 × 95 nm; or 35 × 45 × 75 nm for mtDNA cores; and 25 × 45 × 100 nm for nucleoids imaged via mtSSB. Nucleoids encompassed different point density and wide size ranges, speculatively due to different activity stemming from different TFAM/mtDNA stoichiometry/density. Considering twofold lower axial vs. lateral resolution, only bulky DVRE models with an aspect ratio >3 and tilted toward the xy-plane were considered as two proximal nucleoids, suspicious occurring after division following mtDNA replication. The existence of proximal nucleoids in mtDNA-dSTORM 3D images of mtDNA "doubling"-supported possible direct observations of mt nucleoid division after mtDNA replication.
NASA Astrophysics Data System (ADS)
Hermanns, Maria
The Kitaev honeycomb model has become one of the archetypal spin models exhibiting topological phases of matter, where the magnetic moments fractionalize into Majorana fermions interacting with a Z2 gauge field. In this talk, we discuss generalizations of this model to three-dimensional lattice structures. Our main focus is the metallic state that the emergent Majorana fermions form. In particular, we discuss the relation of the nature of this Majorana metal to the details of the underlying lattice structure. Besides (almost) conventional metals with a Majorana Fermi surface, one also finds various realizations of Dirac semi-metals, where the gapless modes form Fermi lines or even Weyl nodes. We introduce a general classification of these gapless quantum spin liquids using projective symmetry analysis. Furthermore, we briefly outline why these Majorana metals in 3D Kitaev systems provide an even richer variety of Dirac and Weyl phases than possible for electronic matter and comment on possible experimental signatures. Work done in collaboration with Kevin O'Brien and Simon Trebst.
Locomotive wheel 3D reconstruction
NASA Astrophysics Data System (ADS)
Guan, Xin; Luo, Zhisheng; Gao, Xiaorong; Wu, Jianle
2010-08-01
In the article, a system, which is used to reconstruct locomotive wheels, is described, helping workers detect the condition of a wheel through a direct view. The system consists of a line laser, a 2D camera, and a computer. We use 2D camera to capture the line-laser light reflected by the object, a wheel, and then compute the final coordinates of the structured light. Finally, using Matlab programming language, we transform the coordinate of points to a smooth surface and illustrate the 3D view of the wheel. The article also proposes the system structure, processing steps and methods, and sets up an experimental platform to verify the design proposal. We verify the feasibility of the whole process, and analyze the results comparing to standard date. The test results show that this system can work well, and has a high accuracy on the reconstruction. And because there is still no such application working in railway industries, so that it has practical value in railway inspection system.
NASA Astrophysics Data System (ADS)
Mahjoubfar, A.; Goda, K.; Wang, C.; Fard, A.; Adam, J.; Gossett, D. R.; Ayazi, A.; Sollier, E.; Malik, O.; Chen, E.; Liu, Y.; Brown, R.; Sarkhosh, N.; Di Carlo, D.; Jalali, B.
2013-03-01
Laser scanners are essential for scientific research, manufacturing, defense, and medical practice. Unfortunately, often times the speed of conventional laser scanners (e.g., galvanometric mirrors and acousto-optic deflectors) falls short for many applications, resulting in motion blur and failure to capture fast transient information. Here, we present a novel type of laser scanner that offers roughly three orders of magnitude higher scan rates than conventional methods. Our laser scanner, which we refer to as the hybrid dispersion laser scanner, performs inertia-free laser scanning by dispersing a train of broadband pulses both temporally and spatially. More specifically, each broadband pulse is temporally processed by time stretch dispersive Fourier transform and further dispersed into space by one or more diffractive elements such as prisms and gratings. As a proof-of-principle demonstration, we perform 1D line scans at a record high scan rate of 91 MHz and 2D raster scans and 3D volumetric scans at an unprecedented scan rate of 105 kHz. The method holds promise for a broad range of scientific, industrial, and biomedical applications. To show the utility of our method, we demonstrate imaging, nanometer-resolved surface vibrometry, and high-precision flow cytometry with real-time throughput that conventional laser scanners cannot offer due to their low scan rates.
3D multiplexed immunoplasmonics microscopy
NASA Astrophysics Data System (ADS)
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
NASA Astrophysics Data System (ADS)
Somogyi, A.; Barsi, A.; Molnar, B.; Lovas, T.
2016-06-01
Web-based photo albums that support organizing and viewing the users' images are widely used. These services provide a convenient solution for storing, editing and sharing images. In many cases, the users attach geotags to the images in order to enable using them e.g. in location based applications on social networks. Our paper discusses a procedure that collects open access images from a site frequently visited by tourists. Geotagged pictures showing the image of a sight or tourist attraction are selected and processed in photogrammetric processing software that produces the 3D model of the captured object. For the particular investigation we selected three attractions in Budapest. To assess the geometrical accuracy, we used laser scanner and DSLR as well as smart phone photography to derive reference values to enable verifying the spatial model obtained from the web-album images. The investigation shows how detailed and accurate models could be derived applying photogrammetric processing software, simply by using images of the community, without visiting the site.
Faster, higher quality volume visualization for 3D medical imaging
NASA Astrophysics Data System (ADS)
Kalvin, Alan D.; Laine, Andrew F.; Song, Ting
2008-03-01
The two major volume visualization methods used in biomedical applications are Maximum Intensity Projection (MIP) and Volume Rendering (VR), both of which involve the process of creating sets of 2D projections from 3D images. We have developed a new method for very fast, high-quality volume visualization of 3D biomedical images, based on the fact that the inverse of this process (transforming 2D projections into a 3D image) is essentially equivalent to tomographic image reconstruction. This new method uses the 2D projections acquired by the scanner, thereby obviating the need for the two computationally expensive steps currently required in the complete process of biomedical visualization, that is, (i) reconstructing the 3D image from 2D projection data, and (ii) computing the set of 2D projections from the reconstructed 3D image As well as improvements in computation speed, this method also results in improvements in visualization quality, and in the case of x-ray CT we can exploit this quality improvement to reduce radiation dosage. In this paper, demonstrate the benefits of developing biomedical visualization techniques by directly processing the sensor data acquired by body scanners, rather than by processing the image data reconstructed from the sensor data. We show results of using this approach for volume visualization for tomographic modalities, like x-ray CT, and as well as for MRI.
NASA Technical Reports Server (NTRS)
1997-01-01
Mars Pathfinder's forward rover ramp can be seen successfully unfurled in this image, taken in stereo by the Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses are necessary to identify surface detail. This ramp was not used for the deployment of the microrover Sojourner, which occurred at the end of Sol 2. When this image was taken, Sojourner was still latched to one of the lander's petals, waiting for the command sequence that would execute its descent off of the lander's petal.
The image helped Pathfinder scientists determine whether to deploy the rover using the forward or backward ramps and the nature of the first rover traverse. The metallic object at the lower left of the image is the lander's low-gain antenna. The square at the end of the ramp is one of the spacecraft's magnetic targets. Dust that accumulates on the magnetic targets will later be examined by Sojourner's Alpha Proton X-Ray Spectrometer instrument for chemical analysis. At right, a lander petal is visible.
The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.
Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.
Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right
NASA Astrophysics Data System (ADS)
Becker, J. K.; Bons, P. D.
2009-04-01
Microstructures of rocks play an important role in determining rheological properties and help to reveal the processes that lead to their formation. Some of these processes change the microstructure significantly and may thus have the opposite effect in obliterating any fabrics indicative of the previous history of the rocks. One of these processes is grain boundary migration (GBM). During static recrystallisation, GBM may produce a foam texture that completely overprints a pre-existing grain boundary network and GBM actively influences the rheology of a rock, via its influence on grain size and lattice defect concentration. We here present a new numerical simulation software that is capable of simulating a whole range of processes on the grain scale (it is not limited to grain boundary migration). The software is polyhedron-based, meaning that each grain (or phase) is represented by a polyhedron that has discrete boundaries. The boundary (the shell) of the polyhedron is defined by a set of facets which in turn is defined by a set of vertices. Each structural entity (polyhedron, facets and vertices) can have an unlimited number of parameters (depending on the process to be modeled) such as surface energy, concentration, etc. which can be used to calculate changes of the microstructre. We use the processes of grain boundary migration of a "regular" and a partially molten rock to demonstrate the software. Since this software is 3D, the formation of melt networks in a partially molten rock can also be studied. The interconnected melt network is of fundamental importance for melt segregation and migration in the crust and mantle and can help to understand the core-mantle differentiation of large terrestrial planets.
3D Printing and Its Urologic Applications
Soliman, Youssef; Feibus, Allison H; Baum, Neil
2015-01-01
3D printing is the development of 3D objects via an additive process in which successive layers of material are applied under computer control. This article discusses 3D printing, with an emphasis on its historical context and its potential use in the field of urology. PMID:26028997
Imaging a Sustainable Future in 3D
NASA Astrophysics Data System (ADS)
Schuhr, W.; Lee, J. D.; Kanngieser, E.
2012-07-01
It is the intention of this paper, to contribute to a sustainable future by providing objective object information based on 3D photography as well as promoting 3D photography not only for scientists, but also for amateurs. Due to the presentation of this article by CIPA Task Group 3 on "3D Photographs in Cultural Heritage", the presented samples are masterpieces of historic as well as of current 3D photography concentrating on cultural heritage. In addition to a report on exemplarily access to international archives of 3D photographs, samples for new 3D photographs taken with modern 3D cameras, as well as by means of a ground based high resolution XLITE staff camera and also 3D photographs taken from a captive balloon and the use of civil drone platforms are dealt with. To advise on optimum suited 3D methodology, as well as to catch new trends in 3D, an updated synoptic overview of the 3D visualization technology, even claiming completeness, has been carried out as a result of a systematic survey. In this respect, e.g., today's lasered crystals might be "early bird" products in 3D, which, due to lack in resolution, contrast and color, remember to the stage of the invention of photography.
3D Printing and Its Urologic Applications.
Soliman, Youssef; Feibus, Allison H; Baum, Neil
2015-01-01
3D printing is the development of 3D objects via an additive process in which successive layers of material are applied under computer control. This article discusses 3D printing, with an emphasis on its historical context and its potential use in the field of urology.
NASA Astrophysics Data System (ADS)
Engle, Rob
2008-02-01
This paper discusses the creative and technical challenges encountered during the production of "Beowulf 3D," director Robert Zemeckis' adaptation of the Old English epic poem and the first film to be simultaneously released in IMAX 3D and digital 3D formats.
Teaching Geography with 3-D Visualization Technology
ERIC Educational Resources Information Center
Anthamatten, Peter; Ziegler, Susy S.
2006-01-01
Technology that helps students view images in three dimensions (3-D) can support a broad range of learning styles. "Geo-Wall systems" are visualization tools that allow scientists, teachers, and students to project stereographic images and view them in 3-D. We developed and presented 3-D visualization exercises in several undergraduate courses.…
Expanding Geometry Understanding with 3D Printing
ERIC Educational Resources Information Center
Cochran, Jill A.; Cochran, Zane; Laney, Kendra; Dean, Mandi
2016-01-01
With the rise of personal desktop 3D printing, a wide spectrum of educational opportunities has become available for educators to leverage this technology in their classrooms. Until recently, the ability to create physical 3D models was well beyond the scope, skill, and budget of many schools. However, since desktop 3D printers have become readily…
3D Elastic Seismic Wave Propagation Code
1998-09-23
E3D is capable of simulating seismic wave propagation in a 3D heterogeneous earth. Seismic waves are initiated by earthquake, explosive, and/or other sources. These waves propagate through a 3D geologic model, and are simulated as synthetic seismograms or other graphical output.
3D Flow Visualization Using Texture Advection
NASA Technical Reports Server (NTRS)
Kao, David; Zhang, Bing; Kim, Kwansik; Pang, Alex; Moran, Pat (Technical Monitor)
2001-01-01
Texture advection is an effective tool for animating and investigating 2D flows. In this paper, we discuss how this technique can be extended to 3D flows. In particular, we examine the use of 3D and 4D textures on 3D synthetic and computational fluid dynamics flow fields.
Three-dimensional Probabilistic Earthquake Location Applied to 2002-2003 Mt. Etna Eruption
NASA Astrophysics Data System (ADS)
Mostaccio, A.; Tuve', T.; Zuccarello, L.; Patane', D.; Saccorotti, G.; D'Agostino, M.
2005-12-01
Recorded seismicity for the Mt. Etna volcano, occurred during the 2002-2003 eruption, has been relocated using a probabilistic, non-linear, earthquake location approach. We used the software package NonLinLoc (Lomax et al., 2000) adopting the 3D velocity model obtained by Cocina et al., 2005. We applied our data through different algorithms: (1) via a grid-search; (2) via a Metropolis-Gibbs; and (3) via an Oct-tree. The Oct-Tree algorithm gives efficient, faster and accurate mapping of the PDF (Probability Density Function) of the earthquake location problem. More than 300 seismic events were analyzed in order to compare non-linear location results with the ones obtained by using traditional, linearized earthquake location algorithm such as Hypoellipse, and a 3D linearized inversion (Thurber, 1983). Moreover, we compare 38 focal mechanisms, chosen following stricta criteria selection, with the ones obtained by the 3D and 1D results. Although the presented approach is more of a traditional relocation application, probabilistic earthquake location could be used in routinely survey.
The Estimation and Inversion of Magnetotelluric Data with Static Shift
NASA Astrophysics Data System (ADS)
Wang, X.; Zhou, J.; Zhang, J.; Min, G.; Xia, S.
2015-12-01
IntroductionIn magnetotelluric sounding data processing, the static shift correction is one of the most important steps. Due to the complexity of near-surface inhomogeneous bodies distribution, it is difficult to estimate the static shift of measured data. For this problem, we put forward on the basis of the inversion model for static shift estimation, and reconstructed the initial model with using the original data for 2D or 3D inversion. Estimation and Inversion methodThe magnetotelluric impedance phase has the characteristics of not influenced by the static shift in Two-dimensional electrical structure. The objective function for static shift estimation can be constructed based on impedance phase data. On the basis of normal inversion, utilizing one-dimensional linear search algorithm, combined with the forward modeling, the MT static shift can be estimated.Using estimation results for translation of anomaly measured curve. According to the inversion(1-D) of these translated curve, the initial model for two-dimensional or two-dimensional inversion can be reconstructed. On this basis, we do inversion for the original data, which not only can effectively eliminate the influence of static shift on the deep structure of inversion model, but also can get the right shallow electrical structure in the inversionConclusionThe estimation value of static shift based on impedance phase can be close to the true value. This estimation results can be used to modify the initial model, which makes the deep electric structure of the model more reasonable. On this basis, the inversion of the original data can ensure the correctness of the final inversion results (including shallow and deep).Acknowledgement This paper is supported by National Natural Science Foundation (41274078) and National 863 High Technology Research and Development Program (2014AA06A612).Reference[1] deGroot-Hedlin C. Removal of static shift in two dimensions by regularized inversion[J]. Geophysics, 1991, 56
3-D Perspective Pasadena, California
NASA Technical Reports Server (NTRS)
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
Case study: Beauty and the Beast 3D: benefits of 3D viewing for 2D to 3D conversion
NASA Astrophysics Data System (ADS)
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.
Riemke, Richard Allan
2002-09-01
The Reactor Excursion and Leak Analysis Program with 3D capability1 (RELAP5-3D) is a reactor system analysis code that has been developed at the Idaho National Engineering and Environmental Laboratory (INEEL) for the U. S. Department of Energy (DOE). The 3D capability in RELAP5-3D includes 3D hydrodynamics2 and 3D neutron kinetics3,4. Assessment, verification, and validation of the 3D capability in RELAP5-3D is discussed in the literature5,6,7,8,9,10. Additional assessment, verification, and validation of the 3D capability of RELAP5-3D will be presented in other papers in this users seminar. As with any software, user problems occur. User problems usually fall into the categories of input processing failure, code execution failure, restart/renodalization failure, unphysical result, and installation. This presentation will discuss some of the more generic user problems that have been reported on RELAP5-3D as well as their resolution.
3D laptop for defense applications
NASA Astrophysics Data System (ADS)
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.
3-D Technology Approaches for Biological Ecologies
NASA Astrophysics Data System (ADS)
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).
Automatic 3D video format detection
NASA Astrophysics Data System (ADS)
Zhang, Tao; Wang, Zhe; Zhai, Jiefu; Doyen, Didier
2011-03-01
Many 3D formats exist and will probably co-exist for a long time even if 3D standards are today under definition. The support for multiple 3D formats will be important for bringing 3D into home. In this paper, we propose a novel and effective method to detect whether a video is a 3D video or not, and to further identify the exact 3D format. First, we present how to detect those 3D formats that encode a pair of stereo images into a single image. The proposed method detects features and establishes correspondences between features in the left and right view images, and applies the statistics from the distribution of the positional differences between corresponding features to detect the existence of a 3D format and to identify the format. Second, we present how to detect the frame sequential 3D format. In the frame sequential 3D format, the feature points are oscillating from frame to frame. Similarly, the proposed method tracks feature points over consecutive frames, computes the positional differences between features, and makes a detection decision based on whether the features are oscillating. Experiments show the effectiveness of our method.
Advances toward field application of 3D hydraulic tomography
NASA Astrophysics Data System (ADS)
Cardiff, M. A.; Barrash, W.; Kitanidis, P. K.
2011-12-01
Hydraulic tomography (HT) is a technique that shows great potential for aquifer characterization and one that holds the promise of producing 3D hydraulic property distributions, given suitable equipment. First suggested over 15 years ago, HT assimilates distributed aquifer pressure (head) response data collected during a series of multiple pumping tests to produce estimates of aquifer property variability. Unlike traditional curve-matching analyses, which assume homogeneity or "effective" parameters within the radius of influence of a hydrologic test, HT analysis relies on numerical models with detailed heterogeneity in order to invert for the highly resolved 3D parameter distribution that jointly fits all data. Several numerical and laboratory investigations of characterization using HT have shown that property distributions can be accurately estimated between observation locations when experiments are correctly designed - a property not always shared by other, simpler 1D characterization approaches such as partially-penetrating slug tests. HT may represent one of the best methods available for obtaining detailed 3D aquifer property descriptions, especially in deep or "hard" aquifer materials, where direct-push methods may not be feasible. However, to date HT has not yet been widely adopted at contaminated field sites. We believe that current perceived impediments to HT adoption center around four key issues: 1) A paucity in the scientific literature of proven, cross-validated 3D field applications 2) A lack of guidelines and best practices for performing field 3D HT experiments; 3) Practical difficulty and time commitment associated with the installation of a large number of high-accuracy sampling locations, and the running of a large number of pumping tests; and 4) Computational difficulty associated with solving large-scale inverse problems for parameter identification. In this talk, we present current results in 3D HT research that addresses these four issues
MT3DMSP - A parallelized version of the MT3DMS code
NASA Astrophysics Data System (ADS)
Abdelaziz, Ramadan; Le, Hai Ha
2014-12-01
A parallelized version of the 3-D multi-species transport model MT3DMS was developed and tested. Specifically, the open multiprocessing (OpenMP) was utilized for communication between the processors. MT3DMS emulates the solute transport by dividing the calculation into the flow and transport steps. In this article, a new preconditioner, derived from Symmetric Successive Over Relaxation (SSOR) was added into the generalized conjugate gradient solver. This preconditioner is well suited and appropriate for the parallel architecture. A case study in the test field at TU Bergakademie Freiberg was used to produce the results and analyze the code performance. It was observed that most of running time would be required for the advection, dispersion. As a result, the parallel version decreases significantly running time of solute transport modeling. In addition, this work provides a first attempt to demonstrate the capability and versatility of MT3DMS5P to simulate the solute transport in fractured gneiss rock.
Atmospheric Science Data Center
2013-04-17
article title: Multi-angle Portrayals of Mt. Etna's Plume View Larger Image ... (MISR) capture the energetic eruption of Sicily's Mount Etna volcano on October 29, 2002. Viewing Etna's eruptive activities at MISR's ...
Lack of mitochondrial topoisomerase I (TOP1mt) impairs liver regeneration.
Khiati, Salim; Baechler, Simone A; Factor, Valentina M; Zhang, Hongliang; Huang, Shar-yin N; Dalla Rosa, Ilaria; Sourbier, Carole; Neckers, Leonard; Thorgeirsson, Snorri S; Pommier, Yves
2015-09-01
The liver has an exceptional replicative capacity following partial hepatectomy or chemical injuries. Cellular proliferation requires increased production of energy and essential metabolites, which critically depend on the mitochondria. To determine whether Top1mt, the vertebrate mitochondrial topoisomerase, is involved in this process, we studied liver regeneration after carbon tetrachloride (CCl4) administration. TOP1mt knockout (KO) mice showed a marked reduction in regeneration and hepatocyte proliferation. The hepatic mitochondrial DNA (mtDNA) failed to increase during recovery from CCl4 exposure. Reduced glutathione was also depleted, indicating increased reactive oxygen species (ROS). Steady-state levels of ATP, O2 consumption, mtDNA, and mitochondrial mass were also reduced in primary hepatocytes from CCl4-treated KO mice. To further test whether Top1mt acted by enabling mtDNA regeneration, we tested TOP1mt KO fibroblasts and human colon carcinoma HCT116 cells and measured mtDNA after 3-d treatment with ethidium bromide. Both types of TOP1mt knockout cells showed defective mtDNA regeneration following mtDNA depletion. Our study demonstrates that Top1mt is required for normal mtDNA homeostasis and for linking mtDNA expansion with hepatocyte proliferation. PMID:26305952
Lack of mitochondrial topoisomerase I (TOP1mt) impairs liver regeneration
Khiati, Salim; Baechler, Simone A.; Factor, Valentina M.; Zhang, Hongliang; Huang, Shar-yin N.; Dalla Rosa, Ilaria; Sourbier, Carole; Neckers, Leonard; Thorgeirsson, Snorri S.; Pommier, Yves
2015-01-01
The liver has an exceptional replicative capacity following partial hepatectomy or chemical injuries. Cellular proliferation requires increased production of energy and essential metabolites, which critically depend on the mitochondria. To determine whether Top1mt, the vertebrate mitochondrial topoisomerase, is involved in this process, we studied liver regeneration after carbon tetrachloride (CCl4) administration. TOP1mt knockout (KO) mice showed a marked reduction in regeneration and hepatocyte proliferation. The hepatic mitochondrial DNA (mtDNA) failed to increase during recovery from CCl4 exposure. Reduced glutathione was also depleted, indicating increased reactive oxygen species (ROS). Steady-state levels of ATP, O2 consumption, mtDNA, and mitochondrial mass were also reduced in primary hepatocytes from CCl4-treated KO mice. To further test whether Top1mt acted by enabling mtDNA regeneration, we tested TOP1mt KO fibroblasts and human colon carcinoma HCT116 cells and measured mtDNA after 3-d treatment with ethidium bromide. Both types of TOP1mt knockout cells showed defective mtDNA regeneration following mtDNA depletion. Our study demonstrates that Top1mt is required for normal mtDNA homeostasis and for linking mtDNA expansion with hepatocyte proliferation. PMID:26305952
NASA Astrophysics Data System (ADS)
Cherevatova, M.; Smirnov, M. Yu.; Korja, T.; Pedersen, L. B.; Ebbing, J.; Gradmann, S.; Becken, M.
2015-06-01
New magnetotelluric (MT) data in north-west Fennoscandia were acquired within the framework of the project "Magnetotellurics in the Scandes" (MaSca). The project focuses on the investigation of the crustal and upper mantle lithospheric structure in the transition zone from stable Precambrian cratonic interior to passive continental margin beneath the Caledonian orogen and the Scandinavian Mountains in western Fennoscandia. An array of 59 simultaneous long period and 220 broad-band MT sites were occupied in the summers of 2011 to 2013. The 3-D inversion of the MaSca data was obtained using the ModEM 3-D code. The full impedance and tipper data were used for the inversion. The rocks of Archaean and Proterozoic basement towards east and the Caledonian nappes towards west are modelled as resistive structures. In the central and southern parts, the whole crust is resistive and reflects the Trans-Scandinavian Igneous Belt granitoids. The middle to lower crust of the Svecofennian province is conductive. An uppermost crustal conductor is revealed in the Skellefteå Ore District. The south end of the Kittilä Greenstone Belt is seen in the models as a strong upper to middle crustal conductor. In the Caledonides, the highly conductive alum shales are observed along the Caledonian Thrust Front. A map of the crustal conductance for the north-west Fennoscandian Shield is presented.
Dimensional accuracy of 3D printed vertebra
NASA Astrophysics Data System (ADS)
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.
Stereo 3-D Vision in Teaching Physics
NASA Astrophysics Data System (ADS)
Zabunov, Svetoslav
2012-03-01
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 current paper describes the modern stereo 3-D technologies that are applicable to various tasks in teaching physics in schools, colleges, and universities. Examples of stereo 3-D simulations developed by the author can be observed on online.
Software for 3D radiotherapy dosimetry. Validation
NASA Astrophysics Data System (ADS)
Kozicki, Marek; Maras, Piotr; Karwowski, Andrzej C.
2014-08-01
The subject of this work is polyGeVero® software (GeVero Co., Poland), which has been developed to fill the requirements of fast calculations of 3D dosimetry data with the emphasis on polymer gel dosimetry for radiotherapy. This software comprises four workspaces that have been prepared for: (i) calculating calibration curves and calibration equations, (ii) storing the calibration characteristics of the 3D dosimeters, (iii) calculating 3D dose distributions in irradiated 3D dosimeters, and (iv) comparing 3D dose distributions obtained from measurements with the aid of 3D dosimeters and calculated with the aid of treatment planning systems (TPSs). The main features and functions of the software are described in this work. Moreover, the core algorithms were validated and the results are presented. The validation was performed using the data of the new PABIGnx polymer gel dosimeter. The polyGeVero® software simplifies and greatly accelerates the calculations of raw 3D dosimetry data. It is an effective tool for fast verification of TPS-generated plans for tumor irradiation when combined with a 3D dosimeter. Consequently, the software may facilitate calculations by the 3D dosimetry community. In this work, the calibration characteristics of the PABIGnx obtained through four calibration methods: multi vial, cross beam, depth dose, and brachytherapy, are discussed as well.
[3D reconstructions in radiotherapy planning].
Schlegel, W
1991-10-01
3D Reconstructions from tomographic images are used in the planning of radiation therapy to study important anatomical structures such as the body surface, target volumes, and organs at risk. The reconstructed anatomical models are used to define the geometry of the radiation beams. In addition, 3D voxel models are used for the calculation of the 3D dose distributions with an accuracy, previously impossible to achieve. Further uses of 3D reconstructions are in the display and evaluation of 3D therapy plans, and in the transfer of treatment planning parameters to the irradiation situation with the help of digitally reconstructed radiographs. 3D tomographic imaging with subsequent 3D reconstruction must be regarded as a completely new basis for the planning of radiation therapy, enabling tumor-tailored radiation therapy of localized target volumes with increased radiation doses and improved sparing of organs at risk. 3D treatment planning is currently being evaluated in clinical trials in connection with the new treatment techniques of conformation radiotherapy. Early experience with 3D treatment planning shows that its clinical importance in radiotherapy is growing, but will only become a standard radiotherapy tool when volumetric CT scanning, reliable and user-friendly treatment planning software, and faster and cheaper PACS-integrated medical work stations are accessible to radiotherapists.
Quantifying Interparticle Forces and Heterogeneity in 3D Granular Materials
NASA Astrophysics Data System (ADS)
Hurley, R. C.; Hall, S. A.; Andrade, J. E.; Wright, J.
2016-08-01
Interparticle forces in granular materials are intimately linked to mechanical properties and are known to self-organize into heterogeneous structures, or force chains, under external load. Despite progress in understanding the statistics and spatial distribution of interparticle forces in recent decades, a systematic method for measuring forces in opaque, three-dimensional (3D), frictional, stiff granular media has yet to emerge. In this Letter, we present results from an experiment that combines 3D x-ray diffraction, x-ray tomography, and a numerical force inference technique to quantify interparticle forces and their heterogeneity in an assembly of quartz grains undergoing a one-dimensional compression cycle. Forces exhibit an exponential decay above the mean and partition into strong and weak networks. We find a surprising inverse relationship between macroscopic load and the heterogeneity of interparticle forces, despite the clear emergence of two force chains that span the system.
Quantifying Interparticle Forces and Heterogeneity in 3D Granular Materials.
Hurley, R C; Hall, S A; Andrade, J E; Wright, J
2016-08-26
Interparticle forces in granular materials are intimately linked to mechanical properties and are known to self-organize into heterogeneous structures, or force chains, under external load. Despite progress in understanding the statistics and spatial distribution of interparticle forces in recent decades, a systematic method for measuring forces in opaque, three-dimensional (3D), frictional, stiff granular media has yet to emerge. In this Letter, we present results from an experiment that combines 3D x-ray diffraction, x-ray tomography, and a numerical force inference technique to quantify interparticle forces and their heterogeneity in an assembly of quartz grains undergoing a one-dimensional compression cycle. Forces exhibit an exponential decay above the mean and partition into strong and weak networks. We find a surprising inverse relationship between macroscopic load and the heterogeneity of interparticle forces, despite the clear emergence of two force chains that span the system.
A parallel algorithm for solving the 3d Schroedinger equation
Strickland, Michael; Yager-Elorriaga, David
2010-08-20
We describe a parallel algorithm for solving the time-independent 3d Schroedinger equation using the finite difference time domain (FDTD) method. We introduce an optimized parallelization scheme that reduces communication overhead between computational nodes. We demonstrate that the compute time, t, scales inversely with the number of computational nodes as t {proportional_to} (N{sub nodes}){sup -0.95} {sup {+-} 0.04}. This makes it possible to solve the 3d Schroedinger equation on extremely large spatial lattices using a small computing cluster. In addition, we present a new method for precisely determining the energy eigenvalues and wavefunctions of quantum states based on a symmetry constraint on the FDTD initial condition. Finally, we discuss the usage of multi-resolution techniques in order to speed up convergence on extremely large lattices.
Quantifying Interparticle Forces and Heterogeneity in 3D Granular Materials.
Hurley, R C; Hall, S A; Andrade, J E; Wright, J
2016-08-26
Interparticle forces in granular materials are intimately linked to mechanical properties and are known to self-organize into heterogeneous structures, or force chains, under external load. Despite progress in understanding the statistics and spatial distribution of interparticle forces in recent decades, a systematic method for measuring forces in opaque, three-dimensional (3D), frictional, stiff granular media has yet to emerge. In this Letter, we present results from an experiment that combines 3D x-ray diffraction, x-ray tomography, and a numerical force inference technique to quantify interparticle forces and their heterogeneity in an assembly of quartz grains undergoing a one-dimensional compression cycle. Forces exhibit an exponential decay above the mean and partition into strong and weak networks. We find a surprising inverse relationship between macroscopic load and the heterogeneity of interparticle forces, despite the clear emergence of two force chains that span the system. PMID:27610890
FastScript3D - A Companion to Java 3D
NASA Technical Reports Server (NTRS)
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.
3D PDF - a means of public access to geological 3D - objects, using the example of GTA3D
NASA Astrophysics Data System (ADS)
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.
3D ultrafast ultrasound imaging in vivo.
Provost, Jean; Papadacci, Clement; Arango, Juan Esteban; Imbault, Marion; Fink, Mathias; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu
2014-10-01
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.
3D ultrafast ultrasound imaging in vivo
NASA Astrophysics Data System (ADS)
Provost, Jean; Papadacci, Clement; Esteban Arango, Juan; Imbault, Marion; Fink, Mathias; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu
2014-10-01
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.
3D ultrafast ultrasound imaging in vivo.
Provost, Jean; Papadacci, Clement; Arango, Juan Esteban; Imbault, Marion; Fink, Mathias; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu
2014-10-01
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. PMID:25207828
An aerial 3D printing test mission
NASA Astrophysics Data System (ADS)
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.
NASA Astrophysics Data System (ADS)
Moorkamp, M.; Fishwick, S.; Jones, A. G.
2015-12-01
Typical surface wave tomography can recover well the velocity structure of the upper mantle in the depth range between 70-200km. For a successful inversion, we have to constrain the crustal structure and assess the impact on the resulting models. In addition,we often observe potentially interesting features in the uppermost lithosphere which are poorly resolved and thus their interpretationhas to be approached with great care.We are currently developing a seismically constrained magnetotelluric (MT) inversion approach with the aim of better recovering the lithospheric properties (and thus seismic velocities) in these problematic areas. We perform a 3D MT inversion constrained by a fixed seismic velocity model from surface wave tomography. In order to avoid strong bias, we only utilize information on structural boundaries to combine these two methods. Within the region that is well resolved by both methods, we can then extract a velocity-conductivity relationship. By translating the conductivitiesretrieved from MT into velocities in areas where the velocity model is poorly resolved, we can generate an updated velocity model and test what impactthe updated velocities have on the predicted data.We test this new approach using a MT dataset acquired in central Botswana over the Okwa terrane and the adjacent Kaapvaal and Zimbabwe Cratons togetherwith a tomographic models for the region. Here, both datasets have previously been used to constrain lithospheric structure and show some similarities.We carefully asses the validity of our results by comparing with observations and petrophysical predictions for the conductivity-velocity relationship.
Wow! 3D Content Awakens the Classroom
ERIC Educational Resources Information Center
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…
ERIC Educational Resources Information Center
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…
3D Printed Block Copolymer Nanostructures
ERIC Educational Resources Information Center
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…
Immersive 3D Geovisualization in Higher Education
ERIC Educational Resources Information Center
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…
3D elastic control for mobile devices.
Hachet, Martin; Pouderoux, Joachim; Guitton, Pascal
2008-01-01
To increase the input space of mobile devices, the authors developed a proof-of-concept 3D elastic controller that easily adapts to mobile devices. This embedded device improves the completion of high-level interaction tasks such as visualization of large documents and navigation in 3D environments. It also opens new directions for tomorrow's mobile applications.
Static & Dynamic Response of 3D Solids
1996-07-15
NIKE3D is a large deformations 3D finite element code used to obtain the resulting displacements and stresses from multi-body static and dynamic structural thermo-mechanics problems with sliding interfaces. Many nonlinear and temperature dependent constitutive models are available.
ERIC Educational Resources Information Center
Love, Tyler S.; Roy, Ken
2016-01-01
Health concerns from 3D printing were first documented by Stephens, Azimi, Orch, and Ramos (2013), who found that commercially available 3D printers were producing hazardous levels of ultrafine particles (UFPs) and volatile organic compounds (VOCs) when plastic materials were melted through the extruder. UFPs are particles less than 100 nanometers…
3D Printing of Molecular Models
ERIC Educational Resources Information Center
Gardner, Adam; Olson, Arthur
2016-01-01
Physical molecular models have played a valuable role in our understanding of the invisible nano-scale world. We discuss 3D printing and its use in producing models of the molecules of life. Complex biomolecular models, produced from 3D printed parts, can demonstrate characteristics of molecular structure and function, such as viral self-assembly,…
A 3D Geostatistical Mapping Tool
Weiss, W. W.; Stevenson, Graig; Patel, Ketan; Wang, Jun
1999-02-09
This software provides accurate 3D reservoir modeling tools and high quality 3D graphics for PC platforms enabling engineers and geologists to better comprehend reservoirs and consequently improve their decisions. The mapping algorithms are fractals, kriging, sequential guassian simulation, and three nearest neighbor methods.
Pathways for Learning from 3D Technology
ERIC Educational Resources Information Center
Carrier, L. Mark; Rab, Saira S.; Rosen, Larry D.; Vasquez, Ludivina; Cheever, Nancy A.
2012-01-01
The purpose of this study was to find out if 3D stereoscopic presentation of information in a movie format changes a viewer's experience of the movie content. Four possible pathways from 3D presentation to memory and learning were considered: a direct connection based on cognitive neuroscience research; a connection through "immersion" in that 3D…
Stereo 3-D Vision in Teaching Physics
ERIC Educational Resources Information Center
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…
Rapid approximate inversion of airborne TEM
NASA Astrophysics Data System (ADS)
Fullagar, Peter K.; Pears, Glenn A.; Reid, James E.; Schaa, Ralf
2015-11-01
Rapid interpretation of large airborne transient electromagnetic (ATEM) datasets is highly desirable for timely decision-making in exploration. Full solution 3D inversion of entire airborne electromagnetic (AEM) surveys is often still not feasible on current day PCs. Therefore, two algorithms to perform rapid approximate 3D interpretation of AEM have been developed. The loss of rigour may be of little consequence if the objective of the AEM survey is regional reconnaissance. Data coverage is often quasi-2D rather than truly 3D in such cases, belying the need for `exact' 3D inversion. Incorporation of geological constraints reduces the non-uniqueness of 3D AEM inversion. Integrated interpretation can be achieved most readily when inversion is applied to a geological model, attributed with lithology as well as conductivity. Geological models also offer several practical advantages over pure property models during inversion. In particular, they permit adjustment of geological boundaries. In addition, optimal conductivities can be determined for homogeneous units. Both algorithms described here can operate on geological models; however, they can also perform `unconstrained' inversion if the geological context is unknown. VPem1D performs 1D inversion at each ATEM data location above a 3D model. Interpretation of cover thickness is a natural application; this is illustrated via application to Spectrem data from central Australia. VPem3D performs 3D inversion on time-integrated (resistive limit) data. Conversion to resistive limits delivers a massive increase in speed since the TEM inverse problem reduces to a quasi-magnetic problem. The time evolution of the decay is lost during the conversion, but the information can be largely recovered by constructing a starting model from conductivity depth images (CDIs) or 1D inversions combined with geological constraints if available. The efficacy of the approach is demonstrated on Spectrem data from Brazil. Both separately and in
Clinical applications of 3-D dosimeters
NASA Astrophysics Data System (ADS)
Wuu, Cheng-Shie
2015-01-01
Both 3-D gels and radiochromic plastic dosimeters, in conjunction with dose image readout systems (MRI or optical-CT), have been employed to measure 3-D dose distributions in many clinical applications. The 3-D dose maps obtained from these systems can provide a useful tool for clinical dose verification for complex treatment techniques such as IMRT, SRS/SBRT, brachytherapy, and proton beam therapy. These complex treatments present high dose gradient regions in the boundaries between the target and surrounding critical organs. Dose accuracy in these areas can be critical, and may affect treatment outcome. In this review, applications of 3-D gels and PRESAGE dosimeter are reviewed and evaluated in terms of their performance in providing information on clinical dose verification as well as commissioning of various treatment modalities. Future interests and clinical needs on studies of 3-D dosimetry are also discussed.
Fabrication of 3D Silicon Sensors
Kok, A.; Hansen, T.E.; Hansen, T.A.; Lietaer, N.; Summanwar, A.; Kenney, C.; Hasi, J.; Da Via, C.; 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.
BEAMS3D Neutral Beam Injection Model
Lazerson, Samuel
2014-04-14
With the advent of applied 3D fi elds in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous velocity reduction, and pitch angle scattering are modeled with the ADAS atomic physics database [1]. Benchmark calculations are presented to validate the collisionless particle orbits, neutral beam injection model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields.
3D Ultrafast Ultrasound Imaging In Vivo
Provost, Jean; Papadacci, Clement; Arango, Juan Esteban; Imbault, Marion; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu
2014-01-01
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 real-time 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 three dimensions 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 capability to track in 3D transient phenomena occurring in the millisecond range within a single ultrafast acquisition was demonstrated for 3-D Shear-Wave Imaging, 3-D Ultrafast Doppler Imaging and finally 3D Ultrafast combined Tissue and Flow Doppler. The propagation of shear waves was tracked in a phantom and used to characterize its stiffness. 3-D Ultrafast Doppler was used to obtain 3-D maps of Pulsed Doppler, Color Doppler, and Power Doppler quantities in a single acquisition and revealed, for the first time, the complex 3-D flow patterns occurring in the ventricles of the human heart during an entire cardiac cycle, and the 3-D 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 3-D Ultrafast Ultrasound Imaging for the 3-D real-time 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. PMID:25207828
The psychology of the 3D experience
NASA Astrophysics Data System (ADS)
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.
Low-cost 3D rangefinder system
NASA Astrophysics Data System (ADS)
Chen, Bor-Tow; Lou, Wen-Shiou; Chen, Chia-Chen; Lin, Hsien-Chang
1998-06-01
Nowadays, 3D data are popularly performed in computer, and 3D browsers manipulate 3D model in the virtual world. Yet, till now, 3D digitizer is still a high-cost product and not a familiar equipment. In order to meet the requirement of 3D fancy world, in this paper, the concept of a low-cost 3D digitizer system is proposed to catch 3D range data from objects. The specified optical design of the 3D extraction is effective to depress the size, and the processing software of the system is compatible with PC to promote its portable capability. Both features contribute a low-cost system in PC environment in contrast to a large system bundled in an expensive workstation platform. In the structure of 3D extraction, laser beam and CCD camera are adopted to construct a 3D sensor. Instead of 2 CCD cameras for capturing laser lines twice before, a 2-in-1 system is proposed to merge 2 images in one CCD which still retains the information of two fields of views to inhibit occlusion problems. Besides, optical paths of two camera views are reflected by mirror in order that the volume of the system can be minified with one rotary axis only. It makes a portable system be more possible to work. Combined with the processing software executable in PC windows system, the proposed system not only saves hardware cost but also processing time of software. The system performance achieves 0.05 mm accuracy. It shows that a low- cost system is more possible to be high-performance.
3D Visualization Development of SIUE Campus
NASA Astrophysics Data System (ADS)
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.
MOM3D/EM-ANIMATE - MOM3D WITH ANIMATION CODE
NASA Technical Reports Server (NTRS)
Shaeffer, J. F.
1994-01-01
MOM3D (LAR-15074) is a FORTRAN method-of-moments electromagnetic analysis algorithm for open or closed 3-D perfectly conducting or resistive surfaces. Radar cross section with plane wave illumination is the prime analysis emphasis; however, provision is also included for local port excitation for computing antenna gain patterns and input impedances. The Electric Field Integral Equation form of Maxwell's equations is solved using local triangle couple basis and testing functions with a resultant system impedance matrix. The analysis emphasis is not only for routine RCS pattern predictions, but also for phenomenological diagnostics: bistatic imaging, currents, and near scattered/total electric fields. The images, currents, and near fields are output in form suitable for animation. MOM3D computes the full backscatter and bistatic radar cross section polarization scattering matrix (amplitude and phase), body currents and near scattered and total fields for plane wave illumination. MOM3D also incorporates a new bistatic k space imaging algorithm for computing down range and down/cross range diagnostic images using only one matrix inversion. MOM3D has been made memory and cpu time efficient by using symmetric matrices, symmetric geometry, and partitioned fixed and variable geometries suitable for design iteration studies. MOM3D may be run interactively or in batch mode on 486 IBM PCs and compatibles, UNIX workstations or larger computers. A 486 PC with 16 megabytes of memory has the potential to solve a 30 square wavelength (containing 3000 unknowns) symmetric configuration. Geometries are described using a triangular mesh input in the form of a list of spatial vertex points and a triangle join connection list. The EM-ANIMATE (LAR-15075) program is a specialized visualization program that displays and animates the near-field and surface-current solutions obtained from an electromagnetics program, in particular, that from MOM3D. The EM-ANIMATE program is windows based and
Medical 3D Printing for the Radiologist.
Mitsouras, Dimitris; Liacouras, Peter; Imanzadeh, Amir; Giannopoulos, Andreas A; Cai, Tianrun; Kumamaru, Kanako K; George, Elizabeth; Wake, Nicole; Caterson, Edward J; Pomahac, Bohdan; Ho, Vincent B; Grant, Gerald T; Rybicki, Frank J
2015-01-01
While use of advanced visualization in radiology is instrumental in diagnosis and communication with referring clinicians, there is an unmet need to render Digital Imaging and Communications in Medicine (DICOM) images as three-dimensional (3D) printed models capable of providing both tactile feedback and tangible depth information about anatomic and pathologic states. Three-dimensional printed models, already entrenched in the nonmedical sciences, are rapidly being embraced in medicine as well as in the lay community. Incorporating 3D printing from images generated and interpreted by radiologists presents particular challenges, including training, materials and equipment, and guidelines. The overall costs of a 3D printing laboratory must be balanced by the clinical benefits. It is expected that the number of 3D-printed models generated from DICOM images for planning interventions and fabricating implants will grow exponentially. Radiologists should at a minimum be familiar with 3D printing as it relates to their field, including types of 3D printing technologies and materials used to create 3D-printed anatomic models, published applications of models to date, and clinical benefits in radiology. Online supplemental material is available for this article.
3D facial expression modeling for recognition
NASA Astrophysics Data System (ADS)
Lu, Xiaoguang; Jain, Anil K.; Dass, Sarat C.
2005-03-01
Current two-dimensional image based face recognition systems encounter difficulties with large variations in facial appearance due to the pose, illumination and expression changes. Utilizing 3D information of human faces is promising for handling the pose and lighting variations. While the 3D shape of a face does not change due to head pose (rigid) and lighting changes, it is not invariant to the non-rigid facial movement and evolution, such as expressions and aging effect. We propose a facial surface matching framework to match multiview facial scans to a 3D face model, where the (non-rigid) expression deformation is explicitly modeled for each subject, resulting in a person-specific deformation model. The thin plate spline (TPS) is applied to model the deformation based on the facial landmarks. The deformation is applied to the 3D neutral expression face model to synthesize the corresponding expression. Both the neutral and the synthesized 3D surface models are used to match a test scan. The surface registration and matching between a test scan and a 3D model are achieved by a modified Iterative Closest Point (ICP) algorithm. Preliminary experimental results demonstrate that the proposed expression modeling and recognition-by-synthesis schemes improve the 3D matching accuracy.
Digital relief generation from 3D models
NASA Astrophysics Data System (ADS)
Wang, Meili; Sun, Yu; Zhang, Hongming; Qian, Kun; Chang, Jian; He, Dongjian
2016-09-01
It is difficult to extend image-based relief generation to high-relief generation, as the images contain insufficient height information. To generate reliefs from three-dimensional (3D) models, it is necessary to extract the height fields from the model, but this can only generate bas-reliefs. To overcome this problem, an efficient method is proposed to generate bas-reliefs and high-reliefs directly from 3D meshes. To produce relief features that are visually appropriate, the 3D meshes are first scaled. 3D unsharp masking is used to enhance the visual features in the 3D mesh, and average smoothing and Laplacian smoothing are implemented to achieve better smoothing results. A nonlinear variable scaling scheme is then employed to generate the final bas-reliefs and high-reliefs. Using the proposed method, relief models can be generated from arbitrary viewing positions with different gestures and combinations of multiple 3D models. The generated relief models can be printed by 3D printers. The proposed method provides a means of generating both high-reliefs and bas-reliefs in an efficient and effective way under the appropriate scaling factors.
NUBEAM developments and 3d halo modeling
NASA Astrophysics Data System (ADS)
Gorelenkova, M. V.; Medley, S. S.; Kaye, S. M.
2012-10-01
Recent developments related to the 3D halo model in NUBEAM code are described. To have a reliable halo neutral source for diagnostic simulation, the TRANSP/NUBEAM code has been enhanced with full implementation of ADAS atomic physic ground state and excited state data for hydrogenic beams and mixed species plasma targets. The ADAS codes and database provide the density and temperature dependence of the atomic data, and the collective nature of the state excitation process. To be able to populate 3D halo output with sufficient statistical resolution, the capability to control the statistics of fast ion CX modeling and for thermal halo launch has been added to NUBEAM. The 3D halo neutral model is based on modification and extension of the ``beam in box'' aligned 3d Cartesian grid that includes the neutral beam itself, 3D fast neutral densities due to CX of partially slowed down fast ions in the beam halo region, 3D thermal neutral densities due to CX deposition and fast neutral recapture source. More details on the 3D halo simulation design will be presented.
Medical 3D Printing for the Radiologist.
Mitsouras, Dimitris; Liacouras, Peter; Imanzadeh, Amir; Giannopoulos, Andreas A; Cai, Tianrun; Kumamaru, Kanako K; George, Elizabeth; Wake, Nicole; Caterson, Edward J; Pomahac, Bohdan; Ho, Vincent B; Grant, Gerald T; Rybicki, Frank J
2015-01-01
While use of advanced visualization in radiology is instrumental in diagnosis and communication with referring clinicians, there is an unmet need to render Digital Imaging and Communications in Medicine (DICOM) images as three-dimensional (3D) printed models capable of providing both tactile feedback and tangible depth information about anatomic and pathologic states. Three-dimensional printed models, already entrenched in the nonmedical sciences, are rapidly being embraced in medicine as well as in the lay community. Incorporating 3D printing from images generated and interpreted by radiologists presents particular challenges, including training, materials and equipment, and guidelines. The overall costs of a 3D printing laboratory must be balanced by the clinical benefits. It is expected that the number of 3D-printed models generated from DICOM images for planning interventions and fabricating implants will grow exponentially. Radiologists should at a minimum be familiar with 3D printing as it relates to their field, including types of 3D printing technologies and materials used to create 3D-printed anatomic models, published applications of models to date, and clinical benefits in radiology. Online supplemental material is available for this article. PMID:26562233
Perception of detail in 3D images
NASA Astrophysics Data System (ADS)
Heynderickx, Ingrid; Kaptein, Ronald
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 to blurring or ghosting, and therefore to a decrease in perceived sharpness. However, people watching stereoscopic videos have reported that the 3D scene contained more details, compared to the 2D scene with identical spatial resolution. This is an interesting notion, that has never been tested in a systematic and quantitative way. To investigate this effect, we had people compare the amount of detail ("detailedness") in pairs of 2D and 3D images. A blur filter was applied to one of the two images, and the blur level was varied using an adaptive staircase procedure. In this way, the blur threshold for which the 2D and 3D image contained perceptually the same amount of detail could be found. Our results show that the 3D image needed to be blurred more than the 2D image. This confirms the earlier qualitative findings that 3D images contain perceptually more details than 2D images with the same spatial resolution.
3D bioprinting of tissues and organs.
Murphy, Sean V; Atala, Anthony
2014-08-01
Additive manufacturing, otherwise known as three-dimensional (3D) printing, is driving major innovations in many areas, such as engineering, manufacturing, art, education and medicine. Recent advances have enabled 3D printing of biocompatible materials, cells and supporting components into complex 3D functional living tissues. 3D bioprinting is being applied to regenerative medicine to address the need for tissues and organs suitable for transplantation. Compared with non-biological printing, 3D bioprinting involves additional complexities, such as the choice of materials, cell types, growth and differentiation factors, and technical challenges related to the sensitivities of living cells and the construction of tissues. Addressing these complexities requires the integration of technologies from the fields of engineering, biomaterials science, cell biology, physics and medicine. 3D bioprinting has already been used for the generation and transplantation of several tissues, including multilayered skin, bone, vascular grafts, tracheal splints, heart tissue and cartilaginous structures. Other applications include developing high-throughput 3D-bioprinted tissue models for research, drug discovery and toxicology. PMID:25093879
Medical 3D Printing for the Radiologist
Mitsouras, Dimitris; Liacouras, Peter; Imanzadeh, Amir; Giannopoulos, Andreas A.; Cai, Tianrun; Kumamaru, Kanako K.; George, Elizabeth; Wake, Nicole; Caterson, Edward J.; Pomahac, Bohdan; Ho, Vincent B.; Grant, Gerald T.
2015-01-01
While use of advanced visualization in radiology is instrumental in diagnosis and communication with referring clinicians, there is an unmet need to render Digital Imaging and Communications in Medicine (DICOM) images as three-dimensional (3D) printed models capable of providing both tactile feedback and tangible depth information about anatomic and pathologic states. Three-dimensional printed models, already entrenched in the nonmedical sciences, are rapidly being embraced in medicine as well as in the lay community. Incorporating 3D printing from images generated and interpreted by radiologists presents particular challenges, including training, materials and equipment, and guidelines. The overall costs of a 3D printing laboratory must be balanced by the clinical benefits. It is expected that the number of 3D-printed models generated from DICOM images for planning interventions and fabricating implants will grow exponentially. Radiologists should at a minimum be familiar with 3D printing as it relates to their field, including types of 3D printing technologies and materials used to create 3D-printed anatomic models, published applications of models to date, and clinical benefits in radiology. Online supplemental material is available for this article. ©RSNA, 2015 PMID:26562233
NASA Astrophysics Data System (ADS)
Moorkamp, Max; Avdeeva, Anna
2016-04-01
The static distortion of magnetotelluric (MT) impedances is a common problem that can prevent detailed imaging of the subsurface. The effect of distortion on the undistorted impedance Z can be described as a multiplication with an unknown, real-valued matrix C. Inverting the observed impedance Zobs = C ṡ Z without any consideration of distortion can result in strong artefacts, particularly in the near-surface. As a consequence, a variety of approaches have been developed to remove as much of the distortion effects as possible or compensate for them in the inversion. However, these either reduce the number of data and thus potentially reduce resolution, or make assumptions about the properties of the matrices C and Z which might not be generally valid. Recently we developed a new 3D inversion approach that includes the four unknown elements of C as parameters in the inversion and showed encouraging result with different synthetic test cases. In this presentation we will focus on the practical aspects of inverting real data with this approach. We will use a combined MT and transient electromagnetic (TEM) dataset acquired over the Kemaliye geothermal field in Turkey. We will demonstrate the improvements in imaging that can be obtained by incorporating distortion in the inversion. Having TEM data at each site, gives us some indication of the amount of distortion and we will compare our recovered distortion values with these measurements. Finally, we will also show in how far the inversion approach is robust in the presence of noise and present recipes for successful inversion with distortion correction.
Extra Dimensions: 3D in PDF Documentation
NASA Astrophysics Data System (ADS)
Graf, Norman A.
2012-12-01
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.
NASA Technical Reports Server (NTRS)
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.
2015-01-01
This manual describes the installation and execution of FUN3D version 12.7, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.
NASA Technical Reports Server (NTRS)
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.
NASA Technical Reports Server (NTRS)
Biedron, Robert T.; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, William L.; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; Rumsey, Christopher L.; Thomas, James L.; Wood, William A.
2015-01-01
This manual describes the installation and execution of FUN3D version 12.6, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.
NASA Technical Reports Server (NTRS)
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.
NASA Technical Reports Server (NTRS)
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.
NASA Technical Reports Server (NTRS)
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.
2015-01-01
This manual describes the installation and execution of FUN3D version 12.8, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.
NASA Technical Reports Server (NTRS)
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.
VALIDATION OF IMPROVED 3D ATR MODEL
Soon Sam Kim; Bruce G. Schnitzler
2005-11-01
A full-core Monte Carlo based 3D model of the Advanced Test Reactor (ATR) was previously developed. [1] An improved 3D model has been developed by the International Criticality Safety Benchmark Evaluation Project (ICSBEP) to eliminate homogeneity of fuel plates of the old model, incorporate core changes into the new model, and to validate against a newer, more complicated core configuration. This new 3D model adds capability for fuel loading design and azimuthal power peaking studies of the ATR fuel elements.
Explicit 3-D Hydrodynamic FEM Program
2000-11-07
DYNA3D 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, includingmore » frictional sliding, single surface contact and automatic contact generation.« less
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.
2015-04-23
A new type of graphene aerogel will make for better energy storage, sensors, nanoelectronics, catalysis and separations. Lawrence Livermore National Laboratory researchers have made graphene aerogel microlattices with an engineered architecture via a 3D printing technique known as direct ink writing. The research appears in the April 22 edition of the journal, Nature Communications. The 3D printed graphene aerogels have high surface area, excellent electrical conductivity, are lightweight, have mechanical stiffness and exhibit supercompressibility (up to 90 percent compressive strain). In addition, the 3D printed graphene aerogel microlattices show an order of magnitude improvement over bulk graphene materials and much better mass transport.
FIT3D: Fitting optical spectra
NASA Astrophysics Data System (ADS)
Sánchez, S. F.; Pérez, E.; Sánchez-Blázquez, P.; González, J. J.; Rosales-Ortega, F. F.; Cano-Díaz, M.; López-Cobá, C.; Marino, R. A.; Gil de Paz, A.; Mollá, M.; López-Sánchez, A. R.; Ascasibar, Y.; Barrera-Ballesteros, J.
2016-09-01
FIT3D fits optical spectra to deblend the underlying stellar population and the ionized gas, and extract physical information from each component. FIT3D is focused on the analysis of Integral Field Spectroscopy data, but is not restricted to it, and is the basis of Pipe3D, a pipeline used in the analysis of datasets like CALIFA, MaNGA, and SAMI. It can run iteratively or in an automatic way to derive the parameters of a large set of spectra.
3D packaging for integrated circuit systems
Chu, D.; Palmer, D.W.
1996-11-01
A goal was set for high density, high performance microelectronics pursued through a dense 3D packing of integrated circuits. A {open_quotes}tool set{close_quotes} of assembly processes have been developed that enable 3D system designs: 3D thermal analysis, silicon electrical through vias, IC thinning, mounting wells in silicon, adhesives for silicon stacking, pretesting of IC chips before commitment to stacks, and bond pad bumping. Validation of these process developments occurred through both Sandia prototypes and subsequent commercial examples.
Investigations in massive 3D gravity
Accioly, Antonio; Helayeel-Neto, Jose; Morais, Jefferson; Turcati, Rodrigo; Scatena, Eslley
2011-05-15
Some interesting gravitational properties of the Bergshoeff-Hohm-Townsend model (massive 3D gravity), such as the presence of a short-range gravitational force in the nonrelativistic limit and the existence of an impact-parameter-dependent gravitational deflection angle, are studied. Interestingly enough, these phenomena have no counterpart in the usual Einstein 3D gravity. In order to better understand the two aforementioned gravitational properties, they are also analyzed in the framework of 3D higher-derivative gravity with the Einstein-Hilbert term with the 'wrong sign'.
An Improved Version of TOPAZ 3D
Krasnykh, Anatoly
2003-07-29
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.
JAR3D Webserver: Scoring and aligning RNA loop sequences to known 3D motifs
Roll, James; Zirbel, Craig L.; Sweeney, Blake; Petrov, Anton I.; Leontis, Neocles
2016-01-01
Many non-coding RNAs have been identified and may function by forming 2D and 3D structures. RNA hairpin and internal loops are often represented as unstructured on secondary structure diagrams, but RNA 3D structures show that most such loops are structured by non-Watson–Crick basepairs and base stacking. Moreover, different RNA sequences can form the same RNA 3D motif. JAR3D finds possible 3D geometries for hairpin and internal loops by matching loop sequences to motif groups from the RNA 3D Motif Atlas, by exact sequence match when possible, and by probabilistic scoring and edit distance for novel sequences. The scoring gauges the ability of the sequences to form the same pattern of interactions observed in 3D structures of the motif. The JAR3D webserver at http://rna.bgsu.edu/jar3d/ takes one or many sequences of a single loop as input, or else one or many sequences of longer RNAs with multiple loops. Each sequence is scored against all current motif groups. The output shows the ten best-matching motif groups. Users can align input sequences to each of the motif groups found by JAR3D. JAR3D will be updated with every release of the RNA 3D Motif Atlas, and so its performance is expected to improve over time. PMID:27235417
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
Do-It-Yourself: 3D Models of Hydrogenic Orbitals through 3D Printing
ERIC Educational Resources Information Center
Griffith, Kaitlyn M.; de Cataldo, Riccardo; Fogarty, Keir H.
2016-01-01
Introductory chemistry students often have difficulty visualizing the 3-dimensional shapes of the hydrogenic electron orbitals without the aid of physical 3D models. Unfortunately, commercially available models can be quite expensive. 3D printing offers a solution for producing models of hydrogenic orbitals. 3D printing technology is widely…
Northern California Seismic Attenuation: 3-D Qp and Qs models
NASA Astrophysics Data System (ADS)
Eberhart-Phillips, D. M.
2015-12-01
The northern California crust exhibits a wide range of rock types and deformation processes which produce pronounced heterogeneity in regional attenuation. Using local earthquakes, 3-D Qp and Qs crustal models have been obtained for this region which includes the San Andreas fault system, the Central Valley, the Sierra Nevada batholith, and the Mendocino subduction volcanic system. Path attenuation t* values were determined from P and S spectra of 959 spatially distributed earthquakes, magnitude 2.5-6.0 from 2005-2014, using 1254 stations from NCEDC networks and IRIS Mendocino and Sierra Nevada temporary arrays. The t* data were used in Q inversions, using existing hypocenters and 3-D velocity models, with basic 10-km node spacing. The uneven data coverage was accounted for with linking of nodes into larger areas in order to provide useful Q images across the 3-D volume. The results at shallow depth (< 2 km) show very low Q in the Sacramento Delta, the Eureka area, and parts of the Bay Area. In the brittle crust, fault zones that have high seismicity exhibit low Q. In the lower crust, low Q is observed along fault zones that have large cumulative displacement and have experienced grain size reduction. Underlying active volcanic areas, low Q features are apparent below 20-km depth. Moderately high Q is associated with igneous rocks of the Sierra Nevada and Salinian block, while the Franciscan subduction complex shows moderately low Q. The most prominent high Q feature is related to the Great Valley Ophiolite.
Computation of optimized arrays for 3-D electrical imaging surveys
NASA Astrophysics Data System (ADS)
Loke, M. H.; Wilkinson, P. B.; Uhlemann, S. S.; Chambers, J. E.; Oxby, L. S.
2014-12-01
3-D electrical resistivity surveys and inversion models are required to accurately resolve structures in areas with very complex geology where 2-D models might suffer from artefacts. Many 3-D surveys use a grid where the number of electrodes along one direction (x) is much greater than in the perpendicular direction (y). Frequently, due to limitations in the number of independent electrodes in the multi-electrode system, the surveys use a roll-along system with a small number of parallel survey lines aligned along the x-direction. The `Compare R' array optimization method previously used for 2-D surveys is adapted for such 3-D surveys. Offset versions of the inline arrays used in 2-D surveys are included in the number of possible arrays (the comprehensive data set) to improve the sensitivity to structures in between the lines. The array geometric factor and its relative error are used to filter out potentially unstable arrays in the construction of the comprehensive data set. Comparisons of the conventional (consisting of dipole-dipole and Wenner-Schlumberger arrays) and optimized arrays are made using a synthetic model and experimental measurements in a tank. The tests show that structures located between the lines are better resolved with the optimized arrays. The optimized arrays also have significantly better depth resolution compared to the conventional arrays.
3D temperature field reconstruction using ultrasound sensing system
NASA Astrophysics Data System (ADS)
Liu, Yuqian; Ma, Tong; Cao, Chengyu; Wang, Xingwei
2016-04-01
3D temperature field reconstruction is of practical interest to the power, transportation and aviation industries and it also opens up opportunities for real time control or optimization of high temperature fluid or combustion process. In our paper, a new distributed optical fiber sensing system consisting of a series of elements will be used to generate and receive acoustic signals. This system is the first active temperature field sensing system that features the advantages of the optical fiber sensors (distributed sensing capability) and the acoustic sensors (non-contact measurement). Signals along multiple paths will be measured simultaneously enabled by a code division multiple access (CDMA) technique. Then a proposed Gaussian Radial Basis Functions (GRBF)-based approach can approximate the temperature field as a finite summation of space-dependent basis functions and time-dependent coefficients. The travel time of the acoustic signals depends on the temperature of the media. On this basis, the Gaussian functions are integrated along a number of paths which are determined by the number and distribution of sensors. The inversion problem to estimate the unknown parameters of the Gaussian functions can be solved with the measured times-of-flight (ToF) of acoustic waves and the length of propagation paths using the recursive least square method (RLS). The simulation results show an approximation error less than 2% in 2D and 5% in 3D respectively. It demonstrates the availability and efficiency of our proposed 3D temperature field reconstruction mechanism.
This 3-D flyby of Tropical Storm Ingrid's rainfall was created from TRMM satellite data for Sept. 16. Heaviest rainfall appears in red towers over the Gulf of Mexico, while moderate rainfall stretc...
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
3DSEM: A 3D microscopy dataset
Tafti, Ahmad P.; Kirkpatrick, Andrew B.; Holz, Jessica D.; Owen, Heather A.; Yu, Zeyun
2015-01-01
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
Tropical Cyclone Jack in Satellite 3-D
This 3-D flyby from NASA's TRMM satellite of Tropical Cyclone Jack on April 21 shows that some of the thunderstorms were shown by TRMM PR were still reaching height of at least 17 km (10.5 miles). ...
An Augmented Reality based 3D Catalog
NASA Astrophysics Data System (ADS)
Yamada, Ryo; Kishimoto, Katsumi
This paper presents a 3D catalog system that uses Augmented Reality technology. The use of Web-based catalog systems that present products in 3D form is increasing in various fields, along with the rapid and widespread adoption of Electronic Commerce. However, 3D shapes could previously only be seen in a virtual space, and it was difficult to understand how the products would actually look in the real world. To solve this, we propose a method that combines the virtual and real worlds simply and intuitively. The method applies Augmented Reality technology, and the system developed based on the method enables users to evaluate 3D virtual products in a real environment.
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.
Cyclone Rusty's Landfall in 3-D
This 3-D image derived from NASA's TRMM satellite Precipitation Radar data on February 26, 2013 at 0654 UTC showed that the tops of some towering thunderstorms in Rusty's eye wall were reaching hei...
3-D Animation of Typhoon Bopha
This 3-D animation of NASA's TRMM satellite data showed Typhoon Bopha tracking over the Philippines on Dec. 3 and moving into the Sulu Sea on Dec. 4, 2012. TRMM saw heavy rain (red) was falling at ...
Palacios field: A 3-D case history
McWhorter, R.; Torguson, B.
1994-12-31
In late 1992, Mitchell Energy Corporation acquired a 7.75 sq mi (20.0 km{sup 2}) 3-D seismic survey over Palacios field. Matagorda County, Texas. The company shot the survey to help evaluate the field for further development by delineating the fault pattern of the producing Middle Oligocene Frio interval. They compare the mapping of the field before and after the 3-D survey. This comparison shows that the 3-D volume yields superior fault imaging and interpretability compared to the dense 2-D data set. The problems with the 2-D data set are improper imaging of small and oblique faults and insufficient coverage over a complex fault pattern. Whereas the 2-D data set validated a simple fault model, the 3-D volume revealed a more complex history of faulting that includes three different fault systems. This discovery enabled them to reconstruct the depositional and structural history of Palacios field.
3D-printed bioanalytical devices
NASA Astrophysics Data System (ADS)
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.
3-D TRMM Flyby of Hurricane Amanda
The TRMM satellite flew over Hurricane Amanda on Tuesday, May 27 at 1049 UTC (6:49 a.m. EDT) and captured rainfall rates and cloud height data that was used to create this 3-D simulated flyby. Cred...
NASA Technical Reports Server (NTRS)
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.
3D Printing for Tissue Engineering
Jia, Jia; Yao, Hai; Mei, Ying
2016-01-01
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 tissue integration (e.g., cellular infiltration, vascularization, and active remodeling). This review will cover several approaches that have advanced the field of 3D printing through novel fabrication methods of tissue engineering constructs. It will also discuss the applications of synthetic and natural materials for 3D printing facilitated tissue fabrication. PMID:26869728
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.
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
Nonlaser-based 3D surface imaging
Lu, Shin-yee; Johnson, R.K.; Sherwood, R.J.
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.
3-D Flyover Visualization of Veil Nebula
This 3-D visualization flies across a small portion of the Veil Nebula as photographed by the Hubble Space Telescope. This region is a small part of a huge expanding remnant from a star that explod...
Future Engineers 3-D Print Timelapse
NASA Challenges K-12 students to create a model of a container for space using 3-D modeling software. Astronauts need containers of all kinds - from advanced containers that can study fruit flies t...
Modeling Cellular Processes in 3-D
Mogilner, Alex; Odde, David
2011-01-01
Summary Recent advances in photonic imaging and fluorescent protein technology offer unprecedented views of molecular space-time dynamics in living cells. At the same time, advances in computing hardware and software enable modeling of ever more complex systems, from global climate to cell division. As modeling and experiment become more closely integrated, we must address the issue of modeling cellular processes in 3-D. Here, we highlight recent advances related to 3-D modeling in cell biology. While some processes require full 3-D analysis, we suggest that others are more naturally described in 2-D or 1-D. Keeping the dimensionality as low as possible reduces computational time and makes models more intuitively comprehensible; however, the ability to test full 3-D models will build greater confidence in models generally and remains an important emerging area of cell biological modeling. PMID:22036197
High Resolution 3d Numerical Modelling of Rockfalls
NASA Astrophysics Data System (ADS)
Agliardi, F.; Crosta, G. B.
Accurate modelling of rockfall dynamics is a major issue for engineering geologists and land planners in rockfall prone areas, both for hazard assessment and the design of countermeasures. Numerical modelling of rockfalls has been generally performed in two dimensions. Thus, this is subjected to the crucial "a priori" choice of the rock- fall path and affected by a significant error due to the lateral dispersion of rockfall trajectories. In this study, an original 3D rockfall simulation program, first developed for regional scale distributed analysis, has been tested at a local scale with a very high spatial resolution, in order to show its performance in modelling site-specific prob- lems (runout definition, hazard assessment, design and verification of barriers). The code is based on a "lumped mass" kinematic algorithm allowing to simulate the free fall, impact-rebound and rolling motion of boulders on a three-dimensional topogra- phy described by a DTM. The code allows to run very detailed 3D simulations with almost no limitations in the number of modeled rockfall sources, slope elements and topographic points, using spatially distributed input data. Two case studies from the Mt. S.Martino area (Lecco, Larian Prealps) and the Gembrasca area (Valfurva, Central Alps), both from the mountainous area of the Lombardia Region (Northern Italy) are presented. Both the two examples are particularly intriguing because of the occurrence of well-known historical events (one of which causing fatalities) and the presence of valuable elements at risk (urban areas, transportation corridors) and defensive mea- sures (elasto-plastic barriers and catch walls). The Mt. S.Martino model is based on a DTM with cell size of 5 m, obtained from a 1:5.000 scale contour map, while the Gembrasca one uses an extremely detailed LIDAR-ALTM laser topography with a cell size of 1 m. The location of rockfall sources and the data used to develop and calibrate the two models have been collected
ERIC Educational Resources Information Center
Sharp, Len
1992-01-01
Provides a personal account of one science teacher's participation in a teacher workshop in which teachers learned about volcanic development, types of eruption, geomorphology, plate tectonics, volcano monitoring, and hazards created by volcanoes by examining Mt. St. Helens. Provides a graphic identifying volcanoes active since 1975. (MDH)
Atmospheric Science Data Center
2013-04-17
... shook the eastern edge of Sicily and parts of mainland Italy during September and October. The eruption of Etna sent a thick blanket ... date: Oct 27, 2002 Images: Italy: Mt. Etna location: Europe thumbnail: ...
3D MPRAGE evaluation of the internal auditory canals.
Shah, M; Ross, J S; Tkach, J; Modic, M T
1993-01-01
A heavily T1-weighted three-dimensional (3D) gradient echo sequence utilizing a 180 degrees inversion pulse has become available for clinical use, called magnetization prepared rapid acquisition gradient echo (MPRAGE). With the appropriate choice of repetition time, echo time, flip angle, and inversion time (TI), T1-weighted imaging can be performed with excellent anatomic detail and a good signal-to-noise ratio. We performed an initial evaluation of this sequence for detection of abnormalities of the internal auditory canals compared with conventional spin echo (SE) imaging. Fifteen men and 15 women were evaluated. Diagnoses included normal (n = 15 patients), acoustic neuromas (n = 7 tumors in 4 patients), cerebellopontine angle meningiomas (n = 3), postoperative for acoustic neuroma without residual tumor (n = 2), postoperative with evidence of residual tumor (n = 3), glomus jugulare (n = 1), Bell palsy (n = 1), and vestibular enhancement of probable viral etiology (n = 1). The 3D MPRAGE study consisted of 128 coronal partitions, (10/4/1), 10 degrees flip angle, 130 x 256 matrix, 2 mm slice thickness. TI time of 350 ms, 1 s recovery time, and 5.43 min examination time. All enhancing lesions identified on the conventional SE T1-weighted imaging were also identified on the MPRAGE imaging. No diagnostic difference existed between the MPRAGE and conventional SE sequences when pathology was present, but the MPRAGE sequence did have poorer resolution in the axial reformats related to the 130 x 256 in-plane matrix. While not currently able to replace conventional two-dimensional SE imaging, 3D MPRAGE may provide a valuable adjunct to the routine imaging protocol. This technique could replace the coronal T1-weighted SE sequence and provide excellent gray-white differentiation and many contiguous thin sections without a great increase in overall examination time. PMID:8491908
3D goes digital: from stereoscopy to modern 3D imaging techniques
NASA Astrophysics Data System (ADS)
Kerwien, N.
2014-11-01
In the 19th century, English physicist Charles Wheatstone discovered stereopsis, the basis for 3D perception. His construction of the first stereoscope established the foundation for stereoscopic 3D imaging. Since then, many optical instruments were influenced by these basic ideas. In recent decades, the advent of digital technologies revolutionized 3D imaging. Powerful readily available sensors and displays combined with efficient pre- or post-processing enable new methods for 3D imaging and applications. This paper draws an arc from basic concepts of 3D imaging to modern digital implementations, highlighting instructive examples from its 175 years of history.
Motif3D: Relating protein sequence motifs to 3D structure.
Gaulton, Anna; Attwood, Teresa K
2003-07-01
Motif3D is a web-based protein structure viewer designed to allow sequence motifs, and in particular those contained in the fingerprints of the PRINTS database, to be visualised on three-dimensional (3D) structures. Additional functionality is provided for the rhodopsin-like G protein-coupled receptors, enabling fingerprint motifs of any of the receptors in this family to be mapped onto the single structure available, that of bovine rhodopsin. Motif3D can be used via the web interface available at: http://www.bioinf.man.ac.uk/dbbrowser/motif3d/motif3d.html.
Assessing 3d Photogrammetry Techniques in Craniometrics
NASA Astrophysics Data System (ADS)
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.
Exploring interaction with 3D volumetric displays
NASA Astrophysics Data System (ADS)
Grossman, Tovi; Wigdor, Daniel; Balakrishnan, Ravin
2005-03-01
Volumetric displays generate true volumetric 3D images by actually illuminating points in 3D space. As a result, viewing their contents is similar to viewing physical objects in the real world. These displays provide a 360 degree field of view, and do not require the user to wear hardware such as shutter glasses or head-trackers. These properties make them a promising alternative to traditional display systems for viewing imagery in 3D. Because these displays have only recently been made available commercially (e.g., www.actuality-systems.com), their current use tends to be limited to non-interactive output-only display devices. To take full advantage of the unique features of these displays, however, it would be desirable if the 3D data being displayed could be directly interacted with and manipulated. We investigate interaction techniques for volumetric display interfaces, through the development of an interactive 3D geometric model building application. While this application area itself presents many interesting challenges, our focus is on the interaction techniques that are likely generalizable to interactive applications for other domains. We explore a very direct style of interaction where the user interacts with the virtual data using direct finger manipulations on and around the enclosure surrounding the displayed 3D volumetric image.
Gierke, Sarah; Wittmann, Torsten
2012-01-01
SUMMARY Background Epithelial remodeling, in which apical-basal polarized cells switch to a migratory phenotype, plays a central role in development and disease of multicellular organisms. Although dynamic microtubules (MTs) are required for directed migration on flat surfaces, how MT dynamics are controlled or contribute to epithelial remodeling in a more physiological three-dimensional (3D) environment is not understood. We use confocal live cell imaging to analyze MT function and dynamics during 3D epithelial morphogenesis and remodeling of polarized Madin-Darby canine kidney (MDCK) epithelial cells that undergo partial epithelial-to-mesenchymal transition (EMT) in response to hepatocyte growth factor (HGF). Results We find that HGF treatment increases MT growth rate before morphological changes are evident, and that large numbers of MTs grow into HGF-induced cell extensions independent of centrosome reorientation. Using lentivirus-mediated shRNA, we demonstrate that EB1, an adaptor protein that mediates recruitment of numerous other +TIP proteins to growing MT plus ends, is required for this HGF-induced MT reorganization. We further show that protrusion and adhesion dynamics are disorganized, and that vesicular trafficking to the tip of HGF-induced cell extensions is disrupted in EB1-depleted cells. Conclusions We conclude that EB1-mediated interactions with growing MTs are important to coordinate cell shape changes and directed migration into the surrounding extracellular matrix during epithelial remodeling in a physiological 3D environment. In contrast, EB1 is not required for the establishment or maintenance of apical-basal cell polarity, suggesting different functions of +TIPs and MTs in different types of cell polarity. PMID:22483942
Recording stereoscopic 3D neurosurgery with a head-mounted 3D camera system.
Lee, Brian; Chen, Brian R; Chen, Beverly B; Lu, James Y; Giannotta, Steven L
2015-06-01
Stereoscopic three-dimensional (3D) imaging can present more information to the viewer and further enhance the learning experience over traditional two-dimensional (2D) video. Most 3D surgical videos are recorded from the operating microscope and only feature the crux, or the most important part of the surgery, leaving out other crucial parts of surgery including the opening, approach, and closing of the surgical site. In addition, many other surgeries including complex spine, trauma, and intensive care unit procedures are also rarely recorded. We describe and share our experience with a commercially available head-mounted stereoscopic 3D camera system to obtain stereoscopic 3D recordings of these seldom recorded aspects of neurosurgery. The strengths and limitations of using the GoPro(®) 3D system as a head-mounted stereoscopic 3D camera system in the operating room are reviewed in detail. Over the past several years, we have recorded in stereoscopic 3D over 50 cranial and spinal surgeries and created a library for education purposes. We have found the head-mounted stereoscopic 3D camera system to be a valuable asset to supplement 3D footage from a 3D microscope. We expect that these comprehensive 3D surgical videos will become an important facet of resident education and ultimately lead to improved patient care.
CFL3D, FUN3d, and NSU3D Contributions to the Fifth Drag Prediction Workshop
NASA Technical Reports Server (NTRS)
Park, Michael A.; Laflin, Kelly R.; Chaffin, Mark S.; Powell, Nicholas; Levy, David W.
2013-01-01
Results presented at the Fifth Drag Prediction Workshop using CFL3D, FUN3D, and NSU3D are described. These are calculations on the workshop provided grids and drag adapted grids. The NSU3D results have been updated to reflect an improvement to skin friction calculation on skewed grids. FUN3D results generated after the workshop are included for custom participant generated grids and a grid from a previous workshop. Uniform grid refinement at the design condition shows a tight grouping in calculated drag, where the variation in the pressure component of drag is larger than the skin friction component. At this design condition, A fine-grid drag value was predicted with a smaller drag adjoint adapted grid via tetrahedral adaption to a metric and mixed-element subdivision. The buffet study produced larger variation than the design case, which is attributed to large differences in the predicted side-of-body separation extent. Various modeling and discretization approaches had a strong impact on predicted side-of-body separation. This large wing root separation bubble was not observed in wind tunnel tests indicating that more work is necessary in modeling wing root juncture flows to predict experiments.
3D and 4D magnetic susceptibility tomography based on complex MR images
Chen, Zikuan; Calhoun, Vince D
2014-11-11
Magnetic susceptibility is the physical property for T2*-weighted magnetic resonance imaging (T2*MRI). The invention relates to methods for reconstructing an internal distribution (3D map) of magnetic susceptibility values, .chi. (x,y,z), of an object, from 3D T2*MRI phase images, by using Computed Inverse Magnetic Resonance Imaging (CIMRI) tomography. The CIMRI technique solves the inverse problem of the 3D convolution by executing a 3D Total Variation (TV) regularized iterative convolution scheme, using a split Bregman iteration algorithm. The reconstruction of .chi. (x,y,z) can be designed for low-pass, band-pass, and high-pass features by using a convolution kernel that is modified from the standard dipole kernel. Multiple reconstructions can be implemented in parallel, and averaging the reconstructions can suppress noise. 4D dynamic magnetic susceptibility tomography can be implemented by reconstructing a 3D susceptibility volume from a 3D phase volume by performing 3D CIMRI magnetic susceptibility tomography at each snapshot time.
Self assembled structures for 3D integration
NASA Astrophysics Data System (ADS)
Rao, Madhav
Three dimensional (3D) micro-scale structures attached to a silicon substrate have various applications in microelectronics. However, formation of 3D structures using conventional micro-fabrication techniques are not efficient and require precise control of processing parameters. Self assembly is a method for creating 3D structures that takes advantage of surface area minimization phenomena. Solder based self assembly (SBSA), the subject of this dissertation, uses solder as a facilitator in the formation of 3D structures from 2D patterns. Etching a sacrificial layer underneath a portion of the 2D pattern allows the solder reflow step to pull those areas out of the substrate plane resulting in a folded 3D structure. Initial studies using the SBSA method demonstrated low yields in the formation of five different polyhedra. The failures in folding were primarily attributed to nonuniform solder deposition on the underlying metal pads. The dip soldering method was analyzed and subsequently refined. A modified dip soldering process provided improved yield among the polyhedra. Solder bridging referred as joining of solder deposited on different metal patterns in an entity influenced the folding mechanism. In general, design parameters such as small gap-spacings and thick metal pads were found to favor solder bridging for all patterns studied. Two types of soldering: face and edge soldering were analyzed. Face soldering refers to the application of solder on the entire metal face. Edge soldering indicates application of solder only on the edges of the metal face. Mechanical grinding showed that face soldered SBSA structures were void free and robust in nature. In addition, the face soldered 3D structures provide a consistent heat resistant solder standoff height that serve as attachments in the integration of dissimilar electronic technologies. Face soldered 3D structures were developed on the underlying conducting channel to determine the thermo-electric reliability of
PLOT3D Export Tool for Tecplot
NASA Technical Reports Server (NTRS)
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
NASA Astrophysics Data System (ADS)
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.
NASA Astrophysics Data System (ADS)
Schultz, A.; Bedrosian, P.; Key, K.; Livelybrooks, D.; Egbert, G. D.; Bowles-martinez, E.; Wannamaker, P. E.
2014-12-01
We report on preliminary analyses of data from the EarthScope MT Transportable Array, and from two high-resolution EarthScope MT studies in Cascadia. The first of these, iMUSH, is acquiring wideband MT data at 150 sites, as well as active and passive seismic data in SW Washington (including Mounts Saint Helens, Adams and Rainier). iMUSH seeks to determine details of crustal magma transport and storage, and to resolve major tectonic controls on volcanism along the arc. iMUSH may help to settle a debate over the origin of the SW Washington Crustal Conductor (SWCC), which covers ~5000 km2and that has alternately been attributed to accreted Eocene metasediments or to an extensive region of partial melt in the lower crust beneath the three volcanoes. The iMUSH array is continguous with an amphibious ~150 station MT experiment (MOCHA) onshore and offshore of the Washington and Oregon forearc. MOCHA iwill image the crust and upper mantle of the subduction system in 3D, constraining the fluid input to the system from offshore and the distribution of fluids released from the down-going slab, including along the transitional zone where Episodic Tremor and Slip occurs. Our goal is to refine our understanding of the segmentation, structure and fluid distribution along the convergent margin segments, and their relationship to the spatial pattern of ETS. In contrast to the active Cascadia margin, the Mid-Continent Rift (MCR) is the trace of a massive igneous event that nearly split North America 1.1 billion years ago. Initial results from 3D inversion of MT Transportable Array data show less fine-scale heterogeneity in the upper mantle (250 km depth) than is evident in western, tectonic North America, but a division at the base of thick lithosphere, with higher conductivities beneath and immediately south of the Great Lakes, than to the south. From the base of the lithosphere to the Moho, this high conductivity feature narrows, ultimately disappearing in the mid-crust. In the
ICER-3D Hyperspectral Image Compression Software
NASA Technical Reports Server (NTRS)
Xie, Hua; Kiely, Aaron; Klimesh, matthew; Aranki, Nazeeh
2010-01-01
Software has been developed to implement the ICER-3D algorithm. ICER-3D effects progressive, three-dimensional (3D), wavelet-based compression of hyperspectral images. If a compressed data stream is truncated, the progressive nature of the algorithm enables reconstruction of hyperspectral data at fidelity commensurate with the given data volume. The ICER-3D software is capable of providing either lossless or lossy compression, and incorporates an error-containment scheme to limit the effects of data loss during transmission. The compression algorithm, which was derived from the ICER image compression algorithm, includes wavelet-transform, context-modeling, and entropy coding subalgorithms. The 3D wavelet decomposition structure used by ICER-3D exploits correlations in all three dimensions of sets of hyperspectral image data, while facilitating elimination of spectral ringing artifacts, using a technique summarized in "Improving 3D Wavelet-Based Compression of Spectral Images" (NPO-41381), NASA Tech Briefs, Vol. 33, No. 3 (March 2009), page 7a. Correlation is further exploited by a context-modeling subalgorithm, which exploits spectral dependencies in the wavelet-transformed hyperspectral data, using an algorithm that is summarized in "Context Modeler for Wavelet Compression of Hyperspectral Images" (NPO-43239), which follows this article. An important feature of ICER-3D is a scheme for limiting the adverse effects of loss of data during transmission. In this scheme, as in the similar scheme used by ICER, the spatial-frequency domain is partitioned into rectangular error-containment regions. In ICER-3D, the partitions extend through all the wavelength bands. The data in each partition are compressed independently of those in the other partitions, so that loss or corruption of data from any partition does not affect the other partitions. Furthermore, because compression is progressive within each partition, when data are lost, any data from that partition received
Turner, D.
1983-08-01
The T-HEMP3D (Transportable HEMP3D) computer program is a derivative of the STEALTH three-dimensional thermodynamics code developed by Science Applications, Inc., under the direction of Ron Hofmann. STEALTH, in turn, is based entirely on the original HEMP3D code written at Lawrence Livermore National Laboratory. The primary advantage STEALTH has over its predecessors is that it was designed using modern structured design techniques, with rigorous programming standards enforced. This yields two benefits. First, the code is easily changeable; this is a necessity for a physics code used for research. The second benefit is that the code is easily transportable between different types of computers. The STEALTH program was transferred to LLNL under a cooperative development agreement. Changes were made primarily in three areas: material specification, coordinate generation, and the addition of sliding surface boundary conditions. The code was renamed T-HEMP3D to avoid confusion with other versions of STEALTH. This document summarizes the input to T-HEMP3D, as used at LLNL. It does not describe the physics simulated by the program, nor the numerical techniques employed. Furthermore, it does not describe the separate job steps of coordinate generation and post-processing, including graphical display of results. (WHK)
The importance of 3D dosimetry
NASA Astrophysics Data System (ADS)
Low, Daniel
2015-01-01
Radiation therapy has been getting progressively more complex for the past 20 years. Early radiation therapy techniques needed only basic dosimetry equipment; motorized water phantoms, ionization chambers, and basic radiographic film techniques. As intensity modulated radiation therapy and image guided therapy came into widespread practice, medical physicists were challenged with developing effective and efficient dose measurement techniques. The complex 3-dimensional (3D) nature of the dose distributions that were being delivered demanded the development of more quantitative and more thorough methods for dose measurement. The quality assurance vendors developed a wide array of multidetector arrays that have been enormously useful for measuring and characterizing dose distributions, and these have been made especially useful with the advent of 3D dose calculation systems based on the array measurements, as well as measurements made using film and portal imagers. Other vendors have been providing 3D calculations based on data from the linear accelerator or the record and verify system, providing thorough evaluation of the dose but lacking quality assurance (QA) of the dose delivery process, including machine calibration. The current state of 3D dosimetry is one of a state of flux. The vendors and professional associations are trying to determine the optimal balance between thorough QA, labor efficiency, and quantitation. This balance will take some time to reach, but a necessary component will be the 3D measurement and independent calculation of delivered radiation therapy dose distributions.
3D Spray Droplet Distributions in Sneezes
NASA Astrophysics Data System (ADS)
Techet, Alexandra; Scharfman, Barry; Bourouiba, Lydia
2015-11-01
3D spray droplet clouds generated during human sneezing are investigated using the Synthetic Aperture Feature Extraction (SAFE) method, which relies on light field imaging (LFI) and synthetic aperture (SA) refocusing computational photographic techniques. An array of nine high-speed cameras are used to image sneeze droplets and tracked the droplets in 3D space and time (3D + T). An additional high-speed camera is utilized to track the motion of the head during sneezing. In the SAFE method, the raw images recorded by each camera in the array are preprocessed and binarized, simplifying post processing after image refocusing and enabling the extraction of feature sizes and positions in 3D + T. These binary images are refocused using either additive or multiplicative methods, combined with thresholding. Sneeze droplet centroids, radii, distributions and trajectories are determined and compared with existing data. The reconstructed 3D droplet centroids and radii enable a more complete understanding of the physical extent and fluid dynamics of sneeze ejecta. These measurements are important for understanding the infectious disease transmission potential of sneezes in various indoor environments.
Extra dimensions: 3D in PDF documentation
Graf, Norman A.
2011-01-11
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) file format in its free Adobe Reader software, Adobe has made it easy to distribute and interact with 3D content. By providing support for scripting and animation, temporal data can also be easily distributed to a wide, non-technical audience. We discuss how the field of radiation imaging could benefit from incorporating full 3D information about not only the detectors, but also the results of the experimental analyses, in its electronic publications. In this article, we present examples drawn from high-energy physics, mathematics and molecular biology which take advantage of this functionality. Furthermore, we demonstrate how 3D detector elements can be documented, using either CAD drawings or other sources such as GEANT visualizations as input.
3D dynamic roadmapping for abdominal catheterizations.
Bender, Frederik; Groher, Martin; Khamene, Ali; Wein, Wolfgang; Heibel, Tim Hauke; Navab, Nassir
2008-01-01
Despite rapid advances in interventional imaging, the navigation of a guide wire through abdominal vasculature remains, not only for novice radiologists, a difficult task. Since this navigation is mostly based on 2D fluoroscopic image sequences from one view, the process is slowed down significantly due to missing depth information and patient motion. We propose a novel approach for 3D dynamic roadmapping in deformable regions by predicting the location of the guide wire tip in a 3D vessel model from the tip's 2D location, respiratory motion analysis, and view geometry. In a first step, the method compensates for the apparent respiratory motion in 2D space before backprojecting the 2D guide wire tip into three dimensional space, using a given projection matrix. To countervail the error connected to the projection parameters and the motion compensation, as well as the ambiguity caused by vessel deformation, we establish a statistical framework, which computes a reliable estimate of the guide wire tip location within the 3D vessel model. With this 2D-to-3D transfer, the navigation can be performed from arbitrary viewing angles, disconnected from the static perspective view of the fluoroscopic sequence. Tests on a realistic breathing phantom and on synthetic data with a known ground truth clearly reveal the superiority of our approach compared to naive methods for 3D roadmapping. The concepts and information presented in this paper are based on research and are not commercially available. PMID:18982662
3D bioprinting for engineering complex tissues.
Mandrycky, Christian; Wang, Zongjie; Kim, Keekyoung; Kim, Deok-Ho
2016-01-01
Bioprinting is a 3D fabrication technology used to precisely dispense cell-laden biomaterials for the construction of complex 3D functional living tissues or artificial organs. While still in its early stages, bioprinting strategies have demonstrated their potential use in regenerative medicine to generate a variety of transplantable tissues, including skin, cartilage, and bone. However, current bioprinting approaches still have technical challenges in terms of high-resolution cell deposition, controlled cell distributions, vascularization, and innervation within complex 3D tissues. While no one-size-fits-all approach to bioprinting has emerged, it remains an on-demand, versatile fabrication technique that may address the growing organ shortage as well as provide a high-throughput method for cell patterning at the micrometer scale for broad biomedical engineering applications. In this review, we introduce the basic principles, materials, integration strategies and applications of bioprinting. We also discuss the recent developments, current challenges and future prospects of 3D bioprinting for engineering complex tissues. Combined with recent advances in human pluripotent stem cell technologies, 3D-bioprinted tissue models could serve as an enabling platform for high-throughput predictive drug screening and more effective regenerative therapies.
Full-color holographic 3D printer
NASA Astrophysics Data System (ADS)
Takano, Masami; Shigeta, Hiroaki; Nishihara, Takashi; Yamaguchi, Masahiro; Takahashi, Susumu; Ohyama, Nagaaki; Kobayashi, Akihiko; Iwata, Fujio
2003-05-01
A holographic 3D printer is a system that produces a direct hologram with full-parallax information using the 3-dimensional data of a subject from a computer. In this paper, we present a proposal for the reproduction of full-color images with the holographic 3D printer. In order to realize the 3-dimensional color image, we selected the 3 laser wavelength colors of red (λ=633nm), green (λ=533nm), and blue (λ=442nm), and we built a one-step optical system using a projection system and a liquid crystal display. The 3-dimensional color image is obtained by synthesizing in a 2D array the multiple exposure with these 3 wavelengths made on each 250mm elementary hologram, and moving recording medium on a x-y stage. For the natural color reproduction in the holographic 3D printer, we take the approach of the digital processing technique based on the color management technology. The matching between the input and output colors is performed by investigating first, the relation between the gray level transmittance of the LCD and the diffraction efficiency of the hologram and second, by measuring the color displayed by the hologram to establish a correlation. In our first experimental results a non-linear functional relation for single and multiple exposure of the three components were found. These results are the first step in the realization of a natural color 3D image produced by the holographic color 3D printer.
DYNA3D Code Practices and Developments
Lin, L.; Zywicz, E.; Raboin, P.
2000-04-21
DYNA3D is an explicit, finite element code developed to solve high rate dynamic simulations for problems of interest to the engineering mechanics community. The DYNA3D code has been under continuous development since 1976[1] by the Methods Development Group in the Mechanical Engineering Department of Lawrence Livermore National Laboratory. The pace of code development activities has substantially increased in the past five years, growing from one to between four and six code developers. This has necessitated the use of software tools such as CVS (Concurrent Versions System) to help manage multiple version updates. While on-line documentation with an Adobe PDF manual helps to communicate software developments, periodically a summary document describing recent changes and improvements in DYNA3D software is needed. The first part of this report describes issues surrounding software versions and source control. The remainder of this report details the major capability improvements since the last publicly released version of DYNA3D in 1996. Not included here are the many hundreds of bug corrections and minor enhancements, nor the development in DYNA3D between the manual release in 1993[2] and the public code release in 1996.
BEAMS3D Neutral Beam Injection Model
NASA Astrophysics Data System (ADS)
McMillan, Matthew; Lazerson, Samuel A.
2014-09-01
With the advent of applied 3D fields in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous slowing down, and pitch angle scattering are modeled with the ADAS atomic physics database. Elementary benchmark calculations are presented to verify the collisionless particle orbits, NBI model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields. Notice: this manuscript has been authored by Princeton University under Contract Number DE-AC02-09CH11466 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license